Ricardo Avó
email: ricardoavo@ualg.pt

Paula Laurêncio

Maria C R Madeiros
email: cmedeiro@ualg.pt

Transmission Performance of mm-waves on Radio Over Fiber Systems: Dispersion and Intermodulation Issues

Keywords: radio over fiber, optical single sideband, subcarrier multiplexing, intermodulation distortion

Next generation wireless networks must provide high broadband access, which can be achieved by combining the fiber optics and wireless technologies. In this paper we analyze a mm-wave radio over fiber (RoF) optical access network architecture, combining radio subcarrier multiplexing techniques to improve system efficiency with fiber dispersion mitigation provided by optical single sideband modulation techniques. Our results show the system degradation introduced by the fiber link, namely fiber dispersion and intermodulation effects.

Introduction

Consumer bandwidth requirements are increasing, driven by applications requiring high speed data transmission such as regular file transfers which are becoming larger and an increasing number of transparent applications, such as IP Television (IPTV) and Voice over IP (VoIP). The consensus to overcome this bottleneck is to take optical fiber closer to the consumer. Additionally, these needs are placing increasing demands for more bandwidth allocation via wireless access networks. Nowadays, the most used technologies for Wireless Local Area Networks (WLAN) are 802.11b/g/a with throughputs up to ~27 Mbps, the 802.11n should ease the problem with ~100 Mbps throughput [START_REF] Chang | Architectures and Enabling Technologies for Super-Broadband Radio-over-Fiber Optical-Wireless Access Networks[END_REF]. However, such speeds do not match the wireline home networks provided by Fiber To The Home (FTTH) connections, such as 1 Gbit/s Internet. Other problematic scenarios are in-home IPTV distribution, especially with HDTV and future 3D HDTV, or even sharing content from a Personal Video Recorder (PVR) with different TV sets. The scenario on the Wireless Wide Area Networks (WWAN) connections is even worst, with theoretical maximum speeds of 14.4 Mbps with current High-Speed Packet Access (HSPA). The next generation technologies provide 42Mbps in HSPA+ and 100Mbps with Long Term Evolution (LTE).

The increased bandwidth requirements cause spectral congestion at lower microwave frequencies, which are currently used in wireless access networks. In the millimeter-wave (mm-wave) region there is a large bandwidth available, with friendly regulation conditions, especially in the 60 GHz band, which has at least 5 GHz available bandwidth common thought out the main regions [START_REF] Ohata | 1.25Gbps Wireless Gigabit Ethernet Link at 60GHz-Band[END_REF].

The reminder of this paper is organized as follows. In section 2 the contribution to the technological innovation is shown. In section 3, the network architecture is presented, emphasizing the effects of fiber dispersion and intermodulation introduced by the Optical Single Side Band (OSSB) modulator. Section 4 presents the simulation results for the downlink, and finally section 5 concludes the paper.

Contribution to Technological Innovation

Due to the small coverage area, 60 GHz networks require a large number of base stations (BSs) to cover a service area. This requirement has led to the development of system architectures where functions such as signal, routing, processing, handover and frequency allocation are performed at the central office (CO). The best solution for connecting the CO with BSs in such radio network is via an optical fiber network, now known as radio over fiber (RoF) [START_REF] O'reilly | Broadband wireless systems and networks: an enabling role for radio-over-fibre[END_REF]. RoF has proven to be a viable solution to transport analog signals, e.g. CATV on hybrid fiber-coax networks or on PON networks with the RF overlay. By exploiting high bandwidth wavelength-division multiplexing (WDM) networks, an integrated efficient fiber radio backbone network can be realized, where mm-wave carriers are modulated with data and placed on a particular wavelength channel and delivered to a specific BS.

In this paper we analyze the downlink operation of a RoF network that delivers directly the mm-wave signals from the CO to the BSs. The transmission of mm-wave signals over optical fiber is highly impaired by the fiber chromatic dispersion. To minimize this effect OSSB is used. To further improve the system efficiency Sub-Carrier Multiplexing (SCM) is employed, this allows for the use of multiple independent radio channels in each BS. We consider using four independent SCM channels feeding each BS.

System Description

The downlink basic configuration is shown in figure 1. At the central office, four base-band 1 Gbit/s data signals modulate four different microwave carriers (58.1 GHz, 60.3 GHz, 62.5 GHz and 64.7 GHz) by using Binary Phase Shift Keying (BPSK) modulation. The modulated subcarriers are combined and the composite signal is used to externally modulate a laser using OSSB modulation. The optical signal is then delivered to a specific BS through an optical fiber link. At the BS, a photodiode with a bandwidth greater than the subcarrier frequency is used to directly detect the composite signal. The electrical mm-wave signal is filtered, amplified and directly delivered to the BS antenna. This approach has the advantage of a simplified BS design but it is susceptible to fiber chromatic dispersion that severely limits the transmission distance [START_REF] Schmuck | Comparison of optical millimeter-wave system concepts with regard to chromatic dispersion[END_REF]. For this reason the architecture considered here employs OSSB modulation. The OSSB external modulator used in this work is the one proposed in [START_REF] Sieben | Optical single sideband transmission at 10 Gb/s using only electrical dispersion compensation[END_REF]. The optical field at its output is given by:

( ) ( ) ( ) _ ( ) cos( ( ) / 4) exp MZ SSB in c c E t E t x m t jx m t π π π = - . (1)
where

( ) 2 c j t in o E t P e ω =
is the optical field at the input of the MZ modulator, with optical angular frequency ω c and average power P o , x c is the channel modulation parameter, m(t) represents the applied SCM electrical signal composed by N channels using BPSK modulation and ( )

t m ˆ
is its Hilbert transform. Assuming m(t) to be a pure carrier at angular frequency ω m , the optical field at the output of the OSSB modulator can be written as a series of Bessel functions [START_REF] Laurêncio | Dynamic range of optical links employing optical single side-band modulation[END_REF]:

( )       - ∞ -∞ = ∑       - = 2 0 _ ) ( 4 1 cos 2 ) ( π ω ω π t jn I n n t j SSB MZ m c e m J n e P t E . ( 2
)
where J n is n order Bessel function, the modulation index

m I A x m π 2 =
and A m is the m(t) amplitude. For small values of m I only the fundamental harmonic is significant, under this circumstances the modulator can be considered linear and intermodulation introduced by the modulator is not an issue. However, for high values of m I other harmonics become relevant, as shown in figure 2a and may degrade the system performance, this is particularly important when combined with fiber dispersion.

The Effect of Fiber Dispersion

The ideal optical spectrum of a mm-wave over fiber is a signal which uses double sideband modulated (DSB), is composed by the optical carrier at optical frequency f 0 and by the mm-wave carrier f i located at the optical frequency ± f i + f 0 . When the mmwave propagates through fiber modeled as a linear and dispersive link with a frequency response, H L I N K ( z , ω ) = e x p ( -j β 2 ω 2 z / 2 ) , ω is the angular modulation frequency, z is the longitudinal coordinate of the fiber, β 2 =-λ 2 D/(2πc) denotes the group velocity dispersion, with D the dispersion parameter, c the light speed in vacuum and λ the carrier wavelength), the two optical field harmonics, ± f i + f 0, are affected by different phase changes due to the fiber dispersion. Furthermore, upon photodetection the two optical field harmonics interact in such a way leading to a detected photocurrent that change with distance and frequency, as shown in figure 2b. Theoretically, if optical single sideband modulation is employed, and the modulation index is small, dispersion does not affect the propagation of the mm-wave signal [START_REF] Laurêncio | Dynamic range of optical links employing optical single side-band modulation[END_REF].

Note that, in practical systems the OSSB modulator, owing to its inherent nonlinearity, specially for higher values of m I , generates other significant harmonic components as illustrated in figure 2a, and therefore the system behaviour approaches an Optical Double Side Band (ODSB).

The Effect of Intermodulation Distortion

For an OSSB/SCM system, intermodulation distortion mainly arises from the nonlinear characteristics of the optical modulator, the linear fiber dispersion and from the square law characteristics of the photodetection process. Here, we focus on the intermodulation distortion arising from the nonlinear characteristics of the optical modulator. Assuming m(t) to represent the applied SCM electrical signal composed by N channels and ( ) t m ˆ is its Hilbert transform: where i ω represents the RF angular subcarrier of the i th channel ( ) = 1 i u t ± for BPSK (+ for '1' and -for '0'), and i θ is the subcarrier phase.

The optical field at the output of the OSSB modulator, _ ( )

MZ SSB E t , can be expanded as a series of Bessel functions, for small channels modulation indexes (1) and can be rewritten as:

[ ] [ ] [ ] _ 1 1 2 ( ) / 2 exp / 4 1 ( ) ( ) 2 2 ˆ + j 1 ( ) ( ) exp( ) 2 N I MZ SSB o i i i N I i i c i m E t P j j s t s t m j s t s t j t π ω = =       = - - - -               - -       ∏ ∏ (4)
with channel modulation index 2 .

I c m m

x A π = The optical field at the output of a fiber link of length z is given by [START_REF] Laurêncio | Impact of the combined effect of RIN and intermodulation distortion on OSSB/SCM systems[END_REF],

( ) [ ] [ ] 2 2 2 1 1 2 2 2 1 1 2 ( ) / 2 exp / 4 1 ( ) ( ) exp( ) 2 2 2 ˆ 1 ( ) ( ) exp exp( ) 2 2 N I out o i i i N I i i c i m E t P j j s t s t j i z m j j s t s t j i z j t β π ω β ω ω = =      = - × - - - -                + - - - ×           ∏ ∏ (5)
Furthermore, as the envelope of the optical field is detected by a photodetector with responsivity, R λ , the detected photocurrent is proportional to the envelope of optical field at the fiber output. Considering the intermodulation products, the temporal expression of the detected current may be expressed as int ( ) ( ) ( )

DC sig i t i i t i t ≈ + +
, where DC i is the detected current DC term, ( ) sig i t is the SCM electrical signal, int ( ) i t accounts for the intermodulation products, which acts as noise.

In such systems it is important to consider the intermodulation effects between the sub-carriers as well as between sub-carrier and higher harmonics when high modulation indexes are considered.

For small modulation indexes intermodulation can be calculated using (5), however, for high values of m I system simulation is necessary. When using system simulation the bandwidth of each channel and not just the carrier are taken into account.

( ) ( ) ( )

N m i i i i m t A u t sin t ω θ = = + ∑ 1 ˆ( ) ( ) cos( ) N m i i i i m t A u t t ω θ = = - + ∑ (3) a b

Simulation Results

System simulations were performed using VPI TransmissionMaker™. The library blocks of the simulator were complemented when necessary with blocks implemented using MathWorks software tool MATLAB®. The light source considered in the simulation is an ideal laser, with 1 mW of emission power.

Figure 3 shows the simulation overview showing the signal at some system points. The 1 Gbit/s data which is filtered by a 100% roll over square root raised cosine filter. The filtered data modulates the mm-wave carrier using BPSK modulation. The 4 channels are mixed and used to modulate the optical carrier to OSSB with a m I =0.2. After transmission through standard singlemode fiber, operating at 1553 nm, 16 ps/(nm.km) dispersion coefficient, the signal is directly detected by a high speed PIN photodetector. The receiver considered introduces a noise current of 10e -12 / A Hz . The photodetected channels are separated by mixing with the respective carrier and filtered by a 100% roll over square root raised cosine filter.

To measure the intermodulation distortion falling in a given channel, the channel under analysis is switched off, and the intermodulation power falling in the channel is measured. Figure 4a and4b show the simulated received electrical spectrum when the 60 GHz channel is switched off, for two modulation indexes m I =0.44 and m I =1.1 respectively and a fiber length of 5 km. For m I =0.44 the intermodulation power falling in the 60 GHz channel is not relevant whereas for m I =1.1, the intermodulation power resulting from the sum of the different optical field harmonic beats is significant. Intermodulation power also depends on fiber length, since due to dispersion the different optical field harmonics suffer phase changes which depend on fiber length leading to total intermodulation power variations. In some situations, the intermodulation power falling in a given channel can even decrease with distance, as shown in figure 4c. Figure 5 shows the eye diagrams of the received data of the 60 GHz channel corresponding to the two modulation indexes and different fiber lengths. For a fiber length of 0 km as expected for m I =1.1, the received eye presents higher distortion when compared with m I =0.4. For small values of m I intermodulation is not relevant and the system performance is not significantly affected by dispersion, therefore the received eye diagrams are kept widely open when transmission distance increases. However, the most interesting results arise when the distortion introduced by the OSSB modulator is combined with fiber dispersion. For high modulation indexes m I =1.1, the combined effect of dispersion and intermodulation give rise to oscillations on the system performance, for example for a fiber length of 46.8 km the eye is wider than for 9.6 km. Although not shown in this paper, we note that these results depend strongly on the mm-wave carrier frequency.

Conclusions

Although SSB improves the system reach, the intermodulation distortion and fiber dispersion are still the main issues, as shown by our numerical simulation. This implies a careful consideration when choosing the network architecture.

Other optical modulation techniques should be studied, such as optical carrier suppression or optical filtering, to compare the fiber chromatic dispersion effect with our OSSB system. The data transmission rate should be analyzed and its robustness should be compared to different modulation formats. Orthogonal Frequency Multiplexing (OFDM) could be a good candidate to improve the system performance when using high bit rates by dividing the transmission channel in several low rate channels.

Fig. 1 .

 1 Fig. 1. Overall network architecture.

Fig. 2 .

 2 Fig. 2. a) Optical spectrum at the output of the OSSB modulator, for m I =1.1. b) Normalized received optical power for an ideal optical system employing ODSB. Three RF carrier frequencies are considered, 20 GHz, 40 GHz and 60 GHz.

Fig. 3 .

 3 Fig. 3. Overall simulated system with illustrative signals.

Fig. 4 .Fig. 5 .

 45 Fig. 4. Received electrical spectrum, showing intermodulation power falling on the 60 GHz channel. a) m I =0.44 fiber length of 5 km. b) m I =1.1 fiber length of 5 km. c) m I =1.1 fiber length of 50 km. m I =0.4, L=0 km m I =0.4, L=9.6 km m I =0.4, L=46.8 km

Acknowledgments. This work was supported by the Portuguese Foundation for Science and Technology within the project PTDC/EEA-TEL/71678/2006, Research Unity, I&D 631 and by the PhD grant SFRH/BD/29138/2006.


Duncan Sumitra
email: duncan@frick.org

Head

Resources Consortium (NYARC): Collaboration to preserve specialist born-digital art resources

Keywords: Web-archiving, born-digital, collection development, collaboration, GLAM

In late-2013 the New York Art Resources Consortium (NYARC), consisting of the research libraries and archives of three leading art museums in New York City (the Brooklyn Museum, The Frick Art Reference Library of the Frick Collection, and the Museum of Modern Art), implemented a program for web archiving born-digital specialist art and art historical resources. In the three years following the initiation of NYARC's collaborative web archiving program, ten collections of archived art websites have seen steady growth, with particular focus on archiving the websites of the institutions themselves, sites pertaining to New York City galleries, and those of born-digital catalogues raisonnés. NYARC works in partnership with the Internet Archive's Archive-It service to build their web archive collections and harvest web content, as well as partners with those in the galleries, libraries, archives, and museums (GLAM) community to raise awareness about the inherent need for preservation of ephemeral borndigital materials of high risk of disappearance from the live web. NYARC has pioneered the archiving of born-digital catalogue raisonné, with the collection of catalogue raisonné in Archive-It now including 40 discreet projects. NYARC's overall web archive collections now encompass approximately 3,900 sites. While web archiving is still considered an "emerging" area of focus for collection development within libraries and archives, preservation of borndigital materials remains absolutely crucial to future scholarship. Digital art history in particular depends upon the existence and accessibility of these web-native ephemeral materials, with the many use cases for web archive collections by independent scholars only just being considered as big data analysis gains momentum in the humanities. Additionally, given the rapid rate at which citations for web-based materials within scholarly publications suffer from "link rot" or drifting URLs, it is especially pertinent that web archiving becomes a more prominent practice within cultural heritage institutions, universities, and in collaboration with the GLAM community. This paper seeks to examine the current state of web archiving of born-digital art and art history materials, with particular focus on archiving catalogues raisonnés and New York City gallery sites; NYARC's practice of providing free and public access to their complete web archive collections via the new NYARC Discovery interface; and a discussion of future collaboration for the GLAM community.

Introduction

The New York Art Resources Consortium (NYARC) consists of the libraries and archives of three leading art museums in New York City: The Brooklyn Museum, The Frick Collection, and The Museum of Modern Art. NYARC formed in 2006, with the mission to facilitate collaboration that results in enhanced resources to research communities and the shared goals of improving access to art research resources through technology, advancing the scholarly, educational, and cultural enrichment missions of the three museums, and providing leadership in the development of innovative and model information services programs.

The NYARC libraries each have highly specialized collections, and given the unique nature of their consortial holdings, the directors of the NYARC libraries were driven to continue to build collections of specialist art and art historical resources in the born-digital era. NYARC began to explore web archiving as a collection building strategy in 2010, having recognized that publication methods for art research materials, such as auction and exhibition catalogs, and catalogues raisonnés, were drifting from analog to digital formats.

Web archiving is the process of creating collections of URLs, with websites harvested via software tools that crawl the web and capture the digital content as well as the look and feel of sites at a given point in time. These captures are converted to digital files that conform to an ISO standard format called WARC (the Web ARChive file format). WARC files contain the content from a harvested website during a specific capture and web archive collections document the changes that occur in websites over time.

Current State of Web Archiving in the U.S.

Globally, many different types of institutions are engaged in web archiving, the process of collecting, preserving, and enabling access to web-native materials. This includes national libraries and archives, some with a legal deposit mandate in place. Many university libraries and government offices engage in web archiving, as well as smaller museum libraries and consortia. These institutions engage in web archiving to collect web-native resources in their traditional collecting scope, to fulfill a records retention requirement, to document spontaneous events online, and to combat link rot and content drift. Results from the 2016 NDSA survey, "Web Archiving in the United States," show that the majority of institutions engaged in web archiving in the United States are colleges and universities.

A major player in web archiving (in particular within the United States) is the Internet Archive, which offers the largest publicly available web archive in existence, via the Wayback Machine. As of mid-2017, it contains over 150 billion archived webpages and over 100 million websites in 40 or more languages. Approximately one million URLs are added to the Wayback Machine per week. In contrast, many national libraries and archives engaged in web archiving are not able to allow for public access to their web collections and instead must offer access with restrictions only in an onsite reading room.

Archive-It is the subscription web archiving service of the Internet Archive and it helps organizations in harvesting, building, and preserving collections of born-digital content. Presently they partner with over 500 organizations globally. Partner organizations use a web application to collect, catalog, and manage their collections of archived content and Archive-It offers full-text search of partner collections, with content hosted and stored at the Internet Archive data centers.

Results from the 2016 NDSA survey also identified only three percent of the institutions engaged in web archiving in the U.S. as museums (2%) or consortium (1%). A few Archive-It partners do now collect art and art history related websites, yet there remains a significant gap in collecting of websites in this subject area. Rhizome, the New York-based non-profit arts organization developing the Webrecorder tool, has recently made great strides in successfully harvesting born-digital artwoks and social media art.

Many organizations simply are not engaged in web archiving at all -particuarly the content producers. It's important that the library and archives community not assume that publishers are archiving the content that they produce/disseminate, as most content producers/publishers do not archive their digital output. For NYARC, it's particularly notable that auction houses are not archiving their own catalogs and sales results, and much of their content does not exist on their webpages for more than a few months before being removed. Galleries and artists are often also not archiving their own websites, nor are they aware that there would be a need to do so in support of future art historical scholarship. The lack of a U.S. legal deposit program for born-digital resources is also a challenge, as well as the fact that the majority of cultural institutions do not archive their websites and born-digital output.

Given that an estimated 75% of the material online will change, disappear, or drift from it's initial URL each year, preservation has become a significant challenge for ephemeral information sources. The NYARC directors knew that their libraries were well positioned to leverage existing consortial resources in a collaborative way to be nimble in this emerging and challenging territory of web archiving. As we identified that publication methods for art research materials were shifting from analog to digital formats, NYARC began working incrementally to address the inherent challenges of the digital transition. In 2010, NYARC began to explore the efficacy of implementing a consortial web archiving program with a pilot study at the Frick Art Reference Library. The pilot study was followed by a year-long exploratory study, funded by a grant from The Andrew W. Mellon Foundation, as it was clear that establishing a sustainable program of web archiving for the NYARC libraries would require a more focused investigation about publishing trends and perceived technical and organizational challenges for building and preserving a web archive collection. In 2013 NYARC received a two-year grant from the Mellon Foundation, in support of implementing our consortial web archiving program. The implementation grant allowed the NYARC libraries to actively expand our web archive collection and develop workflows for administering it. Web archiving as a collection development activity has become highly critical for the consortium and as of mid-2017 we have archived 3.9 TB of data across ten collections with the use of the Archive-It subscription service-all publicly accessible online.

NYARC's Archive-It Collections

NYARC presently has ten collections in Archive-It and we have archived over 3,900 distinct URLs (commonly referred to as seed URLs, as they are the starting point for the web crawler to harvest a site). We are focusing on collecting subject-based websites for auction houses and their embedded catalogs, catalogues raisonnés, artists' websites, the websites of New York City galleries and art dealers, sites devoted to scholarship for the restitution of lost or looted art, and ephemeral art resources of scholarly value. We also devote a great deal of effort to archiving the institutional websites of the Frick Collection, the Brooklyn Museum, The Museum of Modern Art, and our NYARC consortium site and project sites.

We have found that our growing collections of the websites of New York City galleries and art dealers and those of born-digital catalogues raisonnés are highly unique, with no other organizations seeking to comprehensively collect these resources. At this point we are archiving the sites of 160 galleries on a monthly basis. In contacting the gallerists and discussing our interest in archiving their gallery websites, we have begun to raise awareness of the need for such work -and from these conversations it is clear that web archiving is not yet being considered very heavily in the gallery world. Gallerists have been highly supportive of our program and enthusiastic to participate.

NYARC is presently working to archive the sites of nearly 40 born-digital catalogue raisonné projects and we are the only organization that is partnering with the producers and publishers of these born-digital catalogues in order to preserve them for future public access by researchers. We are meeting with both art historians and platform developers behind the online catalogues raisonnés to discuss the technical challenges of fully harvesting these resources, many of which employ the use of a backend database for catalogue entries. These collections will be of rich value to researchers in the future, particularly those seeking to study the output and representation of specific artists and the evolution of the New York City gallery scene over time. In the relatively short period of time that NYARC has been archiving gallery sites we have already seen a number of galleries close permanently, move to new neighborhoods within the city, and numerous new galleries have opened. Given the extensive number of galleries in New York City, it has been a challenge to scale this collection to cover the many hundreds of sites that would be representative of all New York-based galleries. The gallery world is an area we feel is rich for collaboration with other art libraries via a shared web archiving program with a geographic distribution for stewardship.

Similarly to other existing web archiving initiatives, NYARC's life cycle for our web archiving program begins with collection development, curation, and administration, and spans from harvesting and quality assurance, to preservation, long-term storage, and description and access. Initial steps involving the selection of websites for inclusion, communications with site owners, and especially the harvesting and quality assurance of web crawls, are all quite timeintensive for staff. Quality assurance review has been particularly manual, and thus slowmoving, but we feel it is essential for building representative collections. In dealing with websites about visual art it's especially imporant to capture not only the embedded information, but also the visual appearance and the functionality/behavior of the websites.

NYARC has developed a collaborative collection development policy for websites and we now have a consortial workflow in place for our program. Websites of scholarly value are selected and nominated for inclusion in the consortium's ten curated Archive-It collections, each of which is aligned with the collecting objectives and strengths of the three NYARC libraries. Due to the rapid pace of change in the content, functionality, and features of websites, the collection development policy is reviewed and revised accordingly on a periodic basis. We knew going into the implementation of our program that we faced many challengesamong them: scale, rapidly evolving and new web technologies, cost and limitations of currently available infrastructure or tools, and permissions considerations for intellectual property. Scale is perhaps the greatest challenge, but the requirements of web archiving are time intensive, more complex, and require more decision-making than we were accustomed to with collecting print materials.

Access and Discovery

In 2014, as part of our web archiving grant, we launched the NYARC Discovery research tool. The core objective for NYARC Discovery was to unite our Archive-It collections with additional scholarly resources, such as our books, periodicals, photoarchive images, journals, and e-books. The interface continues to be developed as we unite scholarly resources into this single search environment. A component of our two-year implementation web archiving grant involved review of several discovery layer interface proofs-of-concept, with the requirement of full integration of our web archive collections into the search result set. Staff from our institutions formed a Discovery Working Group to evaluate the proofs-of-concept. We selected the Primo product from Ex Libris, which features a central index, for implementation. NYARC Discovery's hybrid approach in promoting access to our Archive-It collections is via two main access points. The first point of access is the MARC records that our catalogers are creating for both the live and archived versions of all seed URLs in our Archive-It collections (these records are also all made available in OCLC's WorldCat database). The second is via the full-text search results from Archive-It which are achieved with the OpenSearch API integration (this is a dynamic display, thus the result shows in the second display place and no faceting is available due to the API not being included in the central index of Primo). Users now discover full-text search results from NYARC's Archive-It collections with the same ease as identifying a monographic title in NYARC's research collections, and all of the web archive collection content is freely and publicly available via the NYARC Discovery interface and through NYARC's partner page.

In March 2017, in collaboration with Martin Klein of Los Alamos National Laboratory, NYARC also integrated the MEMENTO API into NYARC Discovery. When users search via keyword, they now also have the option to "view all mementos" in addition to NYARC's captures of a site in Archive-It. When the user clicks the link to "view all captures" they are directed to the Memento Time Travel interface in a new window and this interface offers the option to view all available captures of the particular archived resource brought together from 25 different web archives.

The next phase of investigation for NYARC Discovery will pertain to researcher usage and expanded web archive content offerings, including a usability study of the NYARC Discovery interface which we have just begun in collaboration with the School of Information at Pratt Institute in New York City. Additionally, we will work to promote use of web archive collections with institutional staff, researchers, and for data analysis with special projects.

Collaboration in the GLAM Community

The challenges of digital preservation are not unique to art historical scholarship or to our institutions -they are issues faced by a much larger community with an investment in digital preservation and providing access to born-digital materials. Many would agree these issues are better addressed collaboratively by the community in a way that avoids duplication of effort. We've benefited greatly from being active in the web archiving community and sharing information with our colleagues who are undertaking similar work. NYARC is involved with organizations such as the Art Libraries Society of North America (ARLIS/NA), the National Digital Stewardship Alliance (NDSA) in the U.S., the OCLC Web Archiving Metadata Working Group, the Archive-It New York Users Group, and the Metropolitan New York Library Council (METRO) Web Archiving Group. In collaboration with members of the ARLIS/NA Web Archiving Special Interest Group (SIG) and the ARLIS/NA Digital Humanities SIG, a meeting was held at the most recent ARLIS/NA annual conference in New Orleans to discuss a project to create a digital art history registry, which would include web archiving digital art history project sites. This initiative would promote dissemination and centralize access to the variety of projects currently in development and/or publicly accessible.

NYARC is also actively pursuing a collaborative partnership to extend our web archiving program activities to a broader geographic network of art libraries in the U.S., and perhaps ideally those that are already involved with the ARLIS/NA network. We will be working to expand the web archiving of North American gallery websites, as well as institutional websites of the art libraries, in order to more comprehensively address the long-term accessibility of these unique web-based resources.

It's imperative that we make research on the web persistant, as it is estimated that the average lifespan of a unique URL is less than 75 days. The ever-evolving nature of the web often means that URLs in citations no longer link to the original information. In contrast to printed materials that exist for hundreds of years, web-based content seems unreliable and thus researchers are at times reluctant to cite URLs in their own scholarly output. In order for born-digital scholarship to be considered at a level equivalent to print publications, there must be a method for insuring accuracy and permanence. Confidence in permanent access will be vital to integrating born-digital scholarship into the scholarly canon. Fortunately, there are several easy ways to create archived versions of websites and permanent links to URLs (even if you are not part of a larger program of web collecting). One such way is by saving webpages in the Wayback Machine and then referencing the new archived URL that is produced.

The Frick Art Reference Library formed a Digital Art History Lab (DAHL) in late 2014 with the objective of providing art historians with the digital tools and data necessary to explore new methodologies. The DAHL group also works to stimulate collaborations between art historians and specialists from a variety of fields, from computer science to historical Geographic Information Systems (GIS). As part of the DAHL programming, which includes regular lectures and workshops at the library and museum, we taught a workshop in 2016 on web archiving and the preservation of art scholarship. This workshop will be repeated in fall 2017 at the Frick and is open to the public. We have additionally hosted workshops on mapping tools, data visualization, online catalogue raisonné softwares, and open-source web publishing platforms.

Beyond conducting workshops about saving art historical scholarship, we also seek to work in an interdisciplinary capacity with researchers who might benefit from anaylzing the data within the WARC files created via NYARC's web archiving program. We will be able to generate data sets from our WARC files that show key metadata elements representing all crawled resources, longitudinal graph analysis files, and web archive data sets which utilize named-entity recognitions tools to generate a list of all of the people, places, and organizations mentioned in each URI in a collection along with a timestamp. The potential for data visualization is one that excites us as far as the use of these collections and we will be interested to hear from researchers as to how they might envision collaborating to make use of NYARC's collections for data analysis.

Our initial experience in developing a web archiving program, which compliments our historic analog collection development actitivites at the NYARC libraries, leads us to believe that there is rich potential for greater collaboration within the cultural heritage sector and GLAM community. We envision our future collaboration to encompass both shared effort in the collection and preservation of born-digital scholarly resources and exploration of potential researcher use and analysis of web archive data sets.

Figure 1 :

 1 Figure 1: Web archiving life cycle at NYARC

  The development work was done by Lily Pregill (former NYARC Systems Administrator) and Ido Peled of Ex Libris, with the result of NYARC's Archive-It collections being integrated in the Primo interface through use of the already available OpenSearch API. Through the OpenSearch API, full-text results are delivered from NYARC's ten Archive-It collections (and additional Archive-It partner collections could easily be included via the API as well). The default search setting in the interface is to include the web archive results, although users may remove them should they wish. Links out to the full web archive search result set in the Archive-It interface are also provided.

Figure 2 .

 2 Figure 2. NYARC Discovery interface: single search environment includes web archive collection results


Lotte Wilms
email: lotte.wilms@kb.nl

Michiel Cock
email: m.p.cock@vu.nl

Ben Companjen
email: b.a.companjen@library.leidenuniv.nl

Digital Humanities Clinicsleading Dutch librarians into DH

Academic libraries in the Netherlands have the ambition to increase the knowledge level of their librarians on digital humanities (DH). Three libraries therefore set up a series of full-day training events aimed specifically at library professionals of academic and research libraries in the Netherlands, named DH Clinics. The aim of these clinics is to provide basic methodological competencies and technical skills in DH, for a diverse group of library employees, consisting of both subject and technical librarians with basic technical skills. The content of these sessions should 1) enable them to provide services to researchers and students, 2) identify remaining gaps in knowledge or skills that they could address by self-directed learning and 3) (possibly) to automate their daily library work. This paper describes final schedule of the DH Clinics, how we organised the design process by involving the user community and the lessons we learned.

Introduction

Library professionals of academic libraries in the Netherlands have mostly worked with digital humanities (DH) researchers on an ad-hoc basis. Most organisations had not yet formed policy relating to digital humanities when the libraries came in contact with each other at a meeting in 2015. During this meeting, initiated by the KB, National Library of the Netherlands, the Vrije Universiteit Library and the Library Lab of Ghent University and inspired by the dh + lib community of the Association of College and Research Libraries Digital Humanities Special Interest Group 1 , library professionals from the Netherlands and Belgium shared their activities related to DH and agreed to keep sharing experiences through a Google Group. However, due to changes in personnel, the Google Group was only initiated in 2016 and little had changed with regard to activities in the field of digital humanities within the academic library community.

Two members, Lotte Wilms, Digital Scholarship Advisor of the KB and Michiel Cock, at the time team manager Academic Support for Humanities and Social Sciences at the University Library of the Vrije Universiteit Amsterdam, were working independently on training activities on DH for their colleagues and decided to combine their efforts to organise sessions that would be open for all library colleagues from the GLAM community. Together, we proposed our idea for a national training programme to the board of UKB 2 , the Dutch consortium of university libraries and the national library, for institutional support. Our proposal was 1 dh + lib 2 UKB accepted and Ben Companjen, Digital Scholarship Librarian at Leiden University Libraries' Centre for Digital Scholarship was put forward by the director of his library to join us in our endeavour.

Together we started organising what we then named DH Clinics, the Dutch initiative to educate GLAM librarians on the digital humanities.

Inspiration

We were inspired by several other initiatives: Library Carpentry, the Programming Historian and the Digital Scholarship training programme at the British Library. Library Carpentry "introduces you to the fundamentals of computing and provides you with a platform for further self-directed learning"3 and is aimed at librarians. The Programming Historian "offers novice-friendly, peer-reviewed tutorials that help humanists learn a wide range of digital tools, techniques, and workflows to facilitate their research."4 And last, the training programme of the British Library "engages with those operating at the intersection of academic research, cultural heritage and technology to enable innovative use of [their] digital collections, and creates opportunities for library staff to develop skills necessary to support emerging areas of modern scholarship, particularly the Digital Humanities5 ".

Library Carpentry and the Programming Historian are great resources for tutorials on working with data using available software and on programming simple new applications for a specific task. The materials provided by both platforms have been collaboratively created and peer-reviewed. Library Carpentry, like its 'sibling-projects' Software Carpentry and Data Carpentry, provides not just lesson content, but lesson plans as well. The Digital Scholarship training programme run at the British Library showed that librarians not involved with digital tools or scholarship on a daily basis enjoyed the training and feel they benefit from it.

Goals

Our goals for the program are threefold:

1. to teach academic librarians about the basics of digital humanities 2. to strengthen the relationship between libraries and the academic community 3. to build a knowledge network of Dutch librarians working in DH Our first goal is to provide librarians with basic methodological competencies and technical skills in DH. The content of these sessions should enable them to provide services to researchers and students, identify remaining gaps in knowledge or skills that they could address by self-directed learning and (perhaps) to automate their daily library work by using the techniques the clinics introduce them to. We are not setting out to turn them into programmers or data crunchers, but want to boost their knowledge level to where they feel comfortable providing information about DH projects, follow the literature and research, follow online tutorials and hopefully take up the challenge of continuing this professional development by engaging with the DH community.

Second, we wish to provide the library professionals access to a network of digital humanities researchers within and across universities and research institutes, by asking those researchers to teach the sessions in the clinics. We also hope that learning about the computational possibilities in humanities research directly from the researchers themselves, who often talk about their work with great enthusiasm, will spark the librarian's interest in these matters.

Last, we hope the program will provide an opportunity for librarians to connect and build a knowledge network across institutional boundaries, both offline during the sessions and online (e.g. through the aforementioned DH+LIB NL/VL Google Group). If the program is successful, we will maintain the community feeling by organising follow-ups, e.g. in the form of a DH Project Day, in which we collaboratively work on a library related DH project, such as cleaning and linking catalogue data.

Selection of topics

Digital humanities is a term that is difficult, if not impossible, to define using a limited number of research topics. However, a certain selection of topics was needed to decide the scope of the clinics. Not wanting to miss a relevant method or application, we started our selection process with a brainstorm with several librarians working in DH. This produced a list of concepts, methods and software applications. We then compared this list to other educational programmes in DH, most notably The Programming Historian and Johanna Drucker's Introduction to Digital Humanities6 , to make sure we had not missed any important items, which as it happened we did not.

Next to this, we did a literature review on digital humanities in libraries. What does it entail to be a DH librarian and what skills are required, which are currently lacking? 7 Two surveys done in the United States provide a good overview of skills needed for librarians who work in the digital humanities. The Association of Research Libraries published the report 'Supporting Digital Scholarship', written by Rikk Mulligan who surveyed 73 ARL member libraries. Molly Dahl Poremski undertook a similar endeavour and surveyed 117 librarians who agreed with the statement "I am a librarian that works with digital humanities 8 " in her study. The two reports found similar results with regards to skills on DH for librarians. As Poremski states, "it is the technologically advanced skills (digital mapping, text encoding, and computer programming) that are most often lacking in the current digital librarians' skill set" 9 . This was also found by Mulligan who saw that "[t]he greatest gaps remain in visualization (65%), computational text analysis and support (64%), statistical analysis support (60%), and in developing software (54%)." 10 These US based surveys are supported by the recently published report by Christina Kamposiori of Research Libraries UK (RLUK) 11 , who undertook a similar survey amongst 27 libraries, of which 26 were RLUK member organisation and found that those surveyed looked for skills in DH librarians such as programming (77.8%), a knowledge base (77.8%), negotiation and communication skills (66,7%), leadership skills (55,6%) and research skills (59,3%) 12 .

Next to this, we gathered 15 job descriptions to get an overview of the qualifications that libraries ask of their DH librarians (see Figure 1). From this we learned that soft skills such as collaboration, communication and strategic thinking are asked quite often from a DH librarian, but that a general knowledge of digital research methods and tools returns in all descriptions, in one form or another, as is confirmed in the RLUK survey above. This overview is exactly what we intend to provide the Dutch librarians with the DH Clinics.

We believed it was important to not only address the topics we came across in our work as librarians, but to also see what researchers needed and expected from their libraries. We therefore took this discussion to the THATcamp Amsterdam on 27 October 2016 where we proposed a session on 'DH and Libraries' 13 . The accepted session gave us the opportunity to discuss our ideas and list of topics with researchers from the DH community. This provided us with very useful feedback, both on the role of a DH librarian in general and on our ideas for the programme. The most important advice was to focus on teaching the library professionals about concepts and methods, not specific tools. One specific topic that participants felt librarians did not understand well enough was the influence of data completeness and correctness on DH research, which has been a reason to include data criticism in the programme.

Organisation of topics in sessions

Our list of concepts, methods and software applications was still a very large one, without any self-evident structure that would help us divide the list into training sessions. We therefore mapped the items on our list onto the TaDiRAH 14 research taxonomy (Taxonomy 11 Kamposiori (2017) 12 Kamposiori (2017) 16 13 Cock and Claeyssens (2016) 14 TaDiRAH -Taxonomy of Digital Research Activities in the Humanities of Digital Research Activities in the Humanities). To do this, we also used a subdivision of our topics related to text, structured data and audio visual material. 15 Some general topics we assigned to multiple phases in the taxonomy, e.g. Natural Language Processing (which we assigned to both Enrichment/Annotating and Analysis/Structural Analysis) and XML (which we assigned to both Capture/Transcription and Enrichment/Editing). These borderline cases were few and most of our items could be assigned to one phase.

Looking at this distribution over topics of TaDiRAH and the current practice of libraries in the Netherlands, we decided to select four phases which we felt were underrepresented in academic libraries: capture, creation, enrichment and analysis. Due to the diversity of material we wanted to include and the different approaches needed, we chose to subdivide analysis into text and non-text.

Library community feedback

To ensure the topics we selected from the list are also what the participants expect from the clinics, we invited them to offer feedback on our programme. We put together a survey using Google Forms, in which we asked respondents to indicate their preferences by ranking three possible workshop topics workshop for each day.

Each question had a short introduction about the topic of the day, the proposed workshops and links to more information. The respondents could then select their first, second and third choice of workshop (Figure 2 and Figure 3). We also asked them if we had missed a crucial topic in our programme. Next to this, we asked more general questions about the organisation, such as which day they would prefer the lectures to be on and whether they would like to follow the whole programme or just a (number of) day(s) (see Figure 4). The survey was sent out to members of the Google Group DH+Lib NL/VL, colleagues in the GLAM community and posted as a news item on the KB Lab website16 , which was shared in its newsletter17 and on Twitter18 .

Within the two weeks that the survey was open (25 April -10 May 2017) we received 40 responses, from 14 institutions (see figure 5 below). The timing of the survey was not optimal, as it was the national May holiday during these two weeks and we received several messages from people who would have liked to provided us with feedback, but were away from the office. The open questions led us to adapting some of the workshops we suggested. For example, one respondent added that they would like to know more about how to model data for a database, which was not something we had provided as an option.

Other responses to our open question on what we had missed in the survey will be addressed during the whole programme, such as examples based on current library practice, information about often used software and background information on digital humanities.

Setup

Once the feedback cycle was complete, we could finalise the programme and start the practical organisation of the events. The clinics are scheduled as full-day events with three weeks between each event, from 5 September 2017 until 7 November 2017, organised in central locations in the Netherlands. Each morning session consists of two lectures and the afternoon sessions are practical, hands-on workshops.

To ensure we will reach the widest audience possible, the afternoon sessions are not mandatory. Librarians who only want to know about DH, but have no interest in or time for working with the tools and methods can simply join the lectures, while attendees who wish to be able to work with applications can participate in the workshops. We do require the workshop participants to also attend the lectures in the morning.

Day 5 -Analysis non-text

Analysis of audio visual sources

GIS Computer vision

We intend to incorporate feedback we receive from the participants during the first clinics in further clinics.

Practicalities

To keep an overview of all activities and training materials, we set up a Github Pages website at dhclinics.github.io. From this website we link to the registration forms on Eventbrite 19 . Due to the limited spaces available in the workshops, we ask that no more than two people from one organisation join the workshop.

We do not have our own budget, but work with day sponsors. Libraries and supporting organisations are asked to pledge a small sum (approximately 500 euro) to cover costs for lunch and travel costs for lecturers and workshop instructors. In return they receive 5 minutes of speaking time at the start of their sponsored day and their logo on all online and offline communication of that day.

Lessons learned

Even though the clinics have yet to take place, we have already learned much from the design process. As often, a major lesson is that it is very important to decide your scope. Try to limit it as much as you can, to make sure you can focus on what is important for your cause. We did this for example when deciding which categories to select for a theme. If there was already a good training programme in place within the Netherlands, we chose to not duplicate that.

We also learned that it was quite easy to involve the community that we were working for. The survey was put together quite quickly and respondents were not difficult to find.

However, what was more difficult to find was time. It is important to ensure you have enough free time to work on an effort as big as this, because otherwise things move too slowly. We therefore planned weekly Skype calls with each other and used a Trello 20 board to keep track of what was happening and make sure that we spent the necessary time on the actions we discussed.

By getting together virtually on a weekly basis, we got to keep the speed of our efforts, but it is important to not be too quick. We wanted to organise a first clinic before the summer, but it soon became apparent that we could not get the speakers we needed for this date. We therefore decided to plan all clinics in the fall and winter. Do not be afraid to postpone if that improves your sessions.

19 Eventbrite 20 Trello

Future plans

Registrations for the clinics open in the summer and we will be continuously talking to our participants to improve the following clinics and our communication.

When the DH Clinics are successful we plan to organise a DH Project day (or two) where all participants join forces to design a small DH project together, ideally with a library base, such as catalogue data. We will formulate a research question, acquire source material, clean the data, analyse the data, answer questions and share the results. With this, we hope the participants will be able to put what they learned into practice and to not only provide support in the endeavours of the researchers they work with in their libraries, but also possibly improve their own workflow by applying the method they learn in this project, such as cleaning data, to their daily work.

Figure 1 -

 1 Figure 1 -Soft skills versus hard skills in job descriptions (n=15)

Figure 2 -Figure 3 -

 23 Figure 2 -Example of survey question

Figure 4 -

 4 Figure 4 -Response to question: 'How do you want to follow the clinics?'. Blue is 'I only want to join you for (a few) lectures', dark orange is 'I want to do all lectures and workshops, depending on my agenda' and light orange is 'I want to do some lectures and workshops'.

Figure 5 -

 5 Figure 5 -Number of respondents of the survey and corresponding institutionsThe feedback provided in the multiple choice questions gave us a mostly clear overview of what respondents are interested in. The open questions led us to adapting some of the workshops we suggested. For example, one respondent added that they would like to know more about how to model data for a database, which was not something we had provided as an option.

Library Carpentry

The Programming Historian

[START_REF] Mcgregor | The Digital Scholarship Training Programme at British Library: Concluding Report & Future Developments[END_REF]

[START_REF] Drucker | Introduction to Digital Humanities: Concepts, Methods, and Tutorial for Students and Instructors[END_REF]

For all collected literature, see https://www.zotero.org/groups/969489/liber_digital_humanities_working_group/items/collectionKey/W XP2WW4G

Poremski (2017) 4

[START_REF] Poremski | Evaluating the landscape of digital humanities librarianship[END_REF]

 10 Mulligan (2016) 8

Based on the division of the Dutch research infrastructure consortium CLARIAH (the Common Lab Research Infrastructure for the Arts and Humanities, https://www.clariah.nl) into three work packages

[START_REF] Wilms | Digital Humanities Clinics voor bibliotheekmedewerkers: input gevraagd! Available at[END_REF]

KB Lab newsletter (2017)

KBNLResearch (2017)

The programme is organised in such a way that each clinic is a separate entity, so participants do not have to follow the whole five-day programme. They can pick and choose what they find relevant for their work.

From the survey we conducted, we expect about 30-40 participants for the lectures and 15-20 participants for the workshops, which is also the maximum number of people we can accommodate in a workshop setting.

Lecturers

To find lecturers for the morning sessions, we wrote profiles for each lecturer, such as; Is (or was) responsible for a large digitisation project and can share knowledge on processes, copyright, techniques and data formats. Added bonus would be if the person also has experience with digitisation of audio, video and objects.

With these profiles we contacted the CLARIAH consortium for tips to find lecturers that fit our profiles. With their suggestions and our combined knowledge of the DH field we contacted several people from not only universities, but also research institutes throughout the Netherlands and Belgium. We also paid attention to having a good gender balance and that the people we contacted already gave similar lectures before to ensure the time they needed to prepare would be limited.

The programme of the workshops was finalised after the aforementioned survey was closed. We believe it to be very important to reuse what is available and looked for teachers who would be able to use already existing material, such as the Library Carpentry workshops. Here, we took the same approach as with the lectures and contacted people who already gave similar workshops or were familiar with the material available online.

Schedule

With the final schedule we hope to address several main activities of and related to the digital humanities, which are relevant for library professionals.


Llanos Cuenca
email: llcuenca@cigip.upv.es

Andres Boza
email: aboza@cigip.upv.es

Angel Ortiz
email: aortiz@cigip.upv.es

Enterprise Architecture Framework with Early Business/ICT Alignment for Extended Enterprises

Keywords: Enterprise Engineering, Business and ICT Strategic Alignment, Enterprise Architecture Framework

Incorporating information and communication technology (ICT) is strongly necessary in extended enterprises. To do this, enterprise engineering approach has important benefits; however, there is not a complete framework to model ICT components and ICT/business alignment. This paper presents an enterprise architecture framework for extended enterprises. The main aim enclosed in this paper is to provide a modeling framework from enterprise engineering approach which including ICT. A comparative analysis has been conducted in life cycle phases, modeling views and strategic alignment between different enterprise architectures. Next, the required building blocks have been proposed: ICT conceptualization, application portfolio, maturity model, alignment heuristics and strategic dependencies. This proposal has been applied in the collaborative order management process of a ceramic tile company.

Introduction

The current economic conditions and the high level of market uncertainty, forces the companies to be in a continuous adaptation to respond constant changes. The competitive advantages in the changing business environment have moved organizational structures from single enterprises to extended or virtual enterprise networks. The collaboration of enterprises requires that all of the enterprise elements should interact efficiently with each other based upon a complete framework [START_REF] Choi | An enterprise architecture framework for collaboration of virtual enterprise chains[END_REF]. Information technology allows making better the value chain (improving the enterprise processes and defining new processes) changing the way companies do business. In this sense, it is important to define a framework to model business and information and communication technology components, and its alignment, in an extended enterprise.

In this paper we propose a modeling framework from an enterprise engineering approach identifying views, life cycle and building blocks to model extended enterprises. This framework incorporates in early life cycle phases the required elements for business and information technology alignment.

Nowadays many industrial organizations are focusing specifically on linking and unifying supply chains. This linking process leads to the synchronized behavior of all participants [START_REF] Vasiliu | An integrated modeling approach of the Extended Enterprise using fractals, game theory and neural networks structure The[END_REF]. They form entities, commonly called extended enterprises (EE). Extended Enterprise has been defined as: "Individual companies work together to form inter-enterprise networks across the product value chain in order to survive and achieve business success" [START_REF] Zhang | Extended and Virtual Enterprises -Similarities and Differences[END_REF]. The Extended Enterprise follows a philosophy where people throughout the business supply chain participate in the decision-making process [START_REF] O'neill | The Extended Manufacturing Enterprise Paradigm[END_REF].

In the modern global competitive environment, manufacturing enterprises need active co-operation with a large network of suppliers and customers to form extended enterprises [START_REF] Cheng | Internet-enabled modelling of extended manufacturing enterprises using process-based techniques[END_REF]. With inter-organizational networks, firms begin to perceive the benefits derived from a vertical disintegration process which enables them to concentrate on their distinctive capacities, while identifying and developing mechanisms which boost the rapid configuration of operative structures that are quick to reconfigure and to adapt to rapidly changeable environments [START_REF] Camarinha-Matos | Collaborative networks: a new scientific discipline[END_REF]. Creating new organizational forms requires the intense use of information and communication technology (ICT).

Enterprise architecture is a key issue in the development of enterprises supporting by technology. Enterprise architecture should have addressed more on how to align of business strategy to technology for implementation, and not just focused on business or IT with separated research and development [START_REF] Chen | Architectures for enterprise integration and interoperability:past, present and future[END_REF].

Enterprise Architectures and Modeling Frameworks Review

Enterprise engineering (EE) concerns the analysis, optimization and re-engineering of all or part of business processes, information systems and organization structures in an enterprise or in an enterprise network [START_REF] Vernadat | Enterprise Modeling and Integration[END_REF].

According to Hoogervorst [START_REF] Hoogervorst | Enterprise Governance and Enterprise Engineering[END_REF] this engineering approach has important benefits such as: 1) the formal approach for addressing organized complexity and the realization of a unified and integrated design, 2) the formal identification of all coordination actions makes clear responsibilities. These benefits generally do not appear with other types of business process modeling. To ensure that this design is carried out coherently the concept of enterprise architecture arises. Enterprise architecture (EA) is defined as a way to structure and design the company's organization and operations. Enterprise architecture is a coherent whole of principles, methods and models that are used in the design and realization of an enterprise's organizational structure, business processes, information systems, and infrastructure [START_REF]Enterprise Architecture Modeling -the Issue of Integration[END_REF].

The framework, as it applies to the enterprise, is a logical structure for classifying and organizing the descriptive representations of an enterprise that are significant to the management of the enterprise as well as to the development of the enterprise systems [START_REF] Inmon | Data stores, data warehousing and the Zachman framework[END_REF]. An enterprise architecture framework is applied to describe both the current (as-is) and future (to-be) states [START_REF] Tang | A Comparative Analysis of Architecture Frameworks[END_REF]. The framework should also simplify the enterprise architecture development, since it helps to articulate how the different components of the architecture relate to one another. A framework should provide a general mechanism for defining views. Views are used in modeling because the complexity of an enterprise makes it unfeasible for a single descriptive representation to be comprehensible in its entirety [START_REF] Martin | Architectural principles for enterprise frameworks[END_REF].

Another adjacent concept to EA is Enterprise Modeling (EM). EM describes the EA from various viewpoints in detail to allow specifying and implementing the systems [START_REF] Chen | Architectures for enterprise integration and interoperability:past, present and future[END_REF]. The use of these models in enterprise engineering can shorten design times and increase modeling consistency [START_REF]Vernadat. Standard on enterprise integration and engineering-state of the art[END_REF].

Enterprise models have a life cycle that is related to the life cycle of the modeled entity. EM uses modeling languages, methods and tools chosen according to the life cycle phase (or life cycle activity) of the enterprise. Several architecture frameworks exist today and they all have a modeling framework organizing enterprise model that may have to be created during the life of a business entity [START_REF] Bernus | Handbook on enterprise architecture[END_REF].

All the enterprise architectures contain views in their frameworks, however, life cycle, building blocks, and how the building blocks fit together, is not defined by all of them [START_REF] Ll | Business and IS/IT Strategic Alignment Framework[END_REF].

Comparative Analysis between Enterprise Architecture Frameworks

The Enterprise architectures analyzed have been: TOGAF [START_REF]TOGAF The Open Group Architecture Framework[END_REF], GERAM [START_REF]IFIP-IFAC Task Force: Generalized Enterprise Reference Architecture and Methodology, Version 1.6.2[END_REF], IE-GIP [START_REF] Ortiz | IE-GIP. A proposal for a Methodology to Develop Enterprise Integration Program[END_REF], Zachman [START_REF] Sowa | Extending and formalizing the framework for information-systems architecture[END_REF] and EAP [21]. The comparative analysis has been conducted in life cycle phases (Identification, Conceptualization, Requirements Definition, Design, Implementation Description, Construction, Operation and Decommission) and modeling views (Business view, Information view, Data view, Application view, Technological view, Organizational view and Resource view).

We can summarize that some modeling views are included with the same name in the enterprise architecture frameworks analyzed. In other cases, the modeling views are included but with a different name, finally other views are not explicitly included but can be complemented from other views. Similar conclusions were obtained from life cycle analysis.

The next figure shows the relationships between modeling views and life cycle phases. The identification and conceptualization phases, do not take into account the information, resources, data, applications and technology views.

The requirements definition phase incorporates the information, resources and data views. Only from design specification are considered the applications and technology views (To abbreviate the figure 1 does not include operation and decommission phases). As discussed earlier, ICT is very important for the extended manufacturing and its alignment with business process and business strategies. The figure above shows that it is not possible to define aspects of information, resources, data, application and technology in early stages of life cycle. Incorporating information systems and information technology in the organizations have considerable risks, and these risks are increased when a strategic plan for its incorporation is not done.

There are a number of proposals that relate the alignment models with enterprise architectures [START_REF] Wegmann | A Method and Tool for Business-IT Alignment[END_REF] [23] [START_REF] Plazaola | An Approach to Associate Strategic Business-IT Alignment Assessment to Enterprise Architecture[END_REF] 25]. In most of cases, the strategic alignment is conducted from business strategy to organizational infrastructure. ICT strategy is hardly defined and when it is done, it does not influence in business strategy. So, it is necessary to improve the definition of ICT strategy and its alignment with business strategy in enterprise architecture.

According [START_REF] Chen | SOA, Enterprise Architecture, and Business-IT Alignment: An Integrated Framework[END_REF] in the enterprise architecture approach is not defined how to align and what to align. It is necessary identify what elements must be included in the enterprise architecture framework. The table 1 shows these elements and checks if they are included or not in the enterprise architectures framework analyzed. In some cases, this elements are mentioned in the enterprise architecture but it is not identified how to define them (this case has been labeled as "Limited" in the table ). The identified ICT and alignment components must be incorporated in the enterprise architecture framework in order to facilitate ICT strategic definition and alignment with business strategy in extended manufacturing.

We propose new building blocks according to ICT strategy components: 1) ICT conceptualization, 2) application portfolio and 3) maturity model. Other building blocks are proposed in order to promote strategic alignment between business and ICT: 4) alignment heuristics and 5) strategic dependencies.

1) ICT Conceptualization: The purpose of this building block is that the company validates whether the ICT strategy is fully established for the company and business entity. ICT conceptualization is a checklist to indicate what documents have been completed. Finally, it must also carry out a joint analysis with the business strategy. The ICT objectives may precede the formulation of business objectives and will be used as input to their development.

2) Application portfolio: 2.1) As-Is portfolio: The purpose of the as-is portfolio is to support the information associated with each application and its relationships with as-is business objectives. 2.2) To-Be portfolio: The purpose of the to-be portfolio is to support the information associated with each application and its relationships with tobe business objectives. There must be at least a relationship with a business objective. 2.3) Application and services portfolio: The applications and services portfolio include those that have been identified in the to-be portfolio and those who remain in the as-is portfolio. Each one can be associated with business objectives and business process that execute them.

3) Maturity Model: It is based on the maturity models of [27] and [START_REF] Santana | Towards a business-IT alignment maturity model for collaborative networked organizations[END_REF] and allows you to define the maturity level of strategic alignment. The building block maturity model allows identifying the maturity level reached by the business entity. It is important to define the revision date and the last level assigned to analyze the alignment evolution.

4) Alignment heuristics: Alignment heuristics are used in this case to detect weakness in business and ICT alignment. By using this building block, different views are related by an alignment question. The company will react with improvement actions depending on the answer.

5) Strategic dependencies: The strategic dependencies model is based on i * framework [START_REF] Yu | Modeling Strategic Relationships for Process Reengineering[END_REF]. The strategic dependency building block represents the resource, task or goal dependencies among different actors (roles, organizational units, organization cells or set of roles). It also indicates whether or not dependency is critical for the business entity. The purpose is to detect dependencies between actors. The figure 2 shows as the modeling views have been extended in the enterprise architecture framework proposed.

The relations between new elements described above, and its location in each view and modeling phase can be found in [START_REF] Ll | Business and IS/IT Strategic Alignment Framework[END_REF].

Case Study

This proposal has been applied in a ceramic tile company. It was necessary to identify the components of extended manufacturing process and several interviews with the managers appointed by the company. The business entity selected was the collaborative order management because is a critical process for the company. Information systems and information technology are essential to support this process.

The business and ICT conceptualization was carried out after identifying the business entity. With the definition of the alignment heuristic at this stage, was possible to identify aspects that had not been well resolved in the conceptualization.

The strategic dependencies model helped to identify the dependencies between actors, and allowed detecting bottlenecks and vulnerabilities. First, the actors involved were identified: suppliers, manufacturers, wholesalers and customers (bringing together retailers and end customers). Besides these actors, we propose a new one to be modeled, the computer system, which includes the information system and technology to use, in this way, strategic relationships with it can be modeled.

The application and services portfolio has enabled the company to link the enterprise business processes to applications and services at the macro level through goals. Also, it has allowed a prioritization of the applications.

The maturity model has allowed a detailed analysis of the alignment between business and ICT, with an allocation of values from one to five, where one represents the lowest value. For the company, the result was a low value which represents an emerging alignment. This encouraged the company to improve some alignment aspects.

The table 2 shows an example of strategic dependency identified in the company.

Conclusion

This paper set out the needs for a modeling framework to include information and communication technology in early life cycle phases in extended enterprises.

Traditionally, business strategy is the driver of organization and IT infrastructure. The alignment it is not concerned with the exploitation of emerging IT capabilities to impact new products and services; technology is not seen as competitive advantage.

Hence it is necessary to extend all modeling views to all life cycle phases and to define the strategic alignment components. The proposed framework allows defining ICT strategy, business and IT alignment assessment, incorporating IT definition in earlier life cycle phases, incorporating application and services portfolio and incorporates business and IT alignment maturity model by the following blocks: ICT conceptualization, application portfolio, maturity model, alignment heuristics and strategic dependencies.

Its application to an extended process, (collaborative order management), has allowed validating the usefulness of the framework.

Fig. 1 .

 1 Fig. 1. The incorporation of modeling views in life cycle phases of enterprise architectures.

Fig. 2 .

 2 Fig. 2. Enterprise architecture framework for extended manufacturing.

Table 1 .

 1 ICT and alignment components

		Togaf	Geram IE-GIP Zachman	EAP
	ICT strategy	Yes	No	No	Limited	Limited
	Business and IT alignment assessment	Limited	No	Limited	Limited	Limited
	Incorporating IT
	definition in earlier life
	cycle phases

Table 2 .

 2 Strategic dependency


M Rostami

J Razmi

F Jolai
email: fjolai@ut.ac.ir

Designing a Genetic Algorithm to Solve an Integrated Model in Supply Chain Management Using Fuzzy Goal Programming Approach

Keywords: fuzzy goal programming, supply chain management, genetic algorithm

Application of fuzzy goal programming and genetic algorithm is considered in this paper. We extend a multi-objective model for integrated inventory-production-distribution planning in supply chain (SC). We consider a supply chain network which consists of a manufacture, with multiple plants, multiple distribution centers (DCs), multiple retailers and multiple customers. The manufacturer produces several items. Decision maker's imprecise aspiration levels of goals are incorporated into model using fuzzy goal programming approach. Due to the complexity of problem in large size and in order to get a satisfactory near optimal solution with great speed, a new genetic algorithm is proposed to solve constrained problems. To show the efficiency of the used model and fuzzy goal programming approach and genetic algorithm for the collaborative inventory-production-distribution problem, computational experiments are performed on a hypothetically constructed case problem.

Introduction

Industries around the world are now all rushing the territory of globalization and specialization. Cooperating with good strategic partner is the sure way to tackle the potential problems arising from competition. Companies can achieve the optimum operating efficiency by working with other companies through communication and specialization which evolve a new type of relationship, the SC relationship, among these companies and further faster a new concept in management: the supply chain management (SCM). Production and distribution operations are the two most important operational functions in a SC. To achieve optimal operational performance in a SC, it is critical to integrate these two functions and plan them jointly in a coordinated way [ [START_REF] Abbasbandy | Ranking of fuzzy numbers by sign distance[END_REF], [START_REF] Nozick | Inventory ,transportation,service quality and the location of distribution centers[END_REF]]. Different aspects of integrated problems for different parts of supply chain have been considered in the literatures. Nozick and Turnquist [START_REF] Nozick | Inventory ,transportation,service quality and the location of distribution centers[END_REF] tried to integrate inventory, transportation and location functions of a supply chain. The proposed model has been confined to a single period, single echelon problem with no capacity constraint. Some researchers have investigated fuzzy production planning problems in SC ( [START_REF] Selim | Collaborative production-distribution planning in supply chain: A fuzzy goal programming approach[END_REF], [START_REF] Abbasbandy | Ranking of fuzzy numbers by sign distance[END_REF], [START_REF] Gao | Intelligent decision making in disassembly process based on fuzzy reasoning Petri nets[END_REF]). Decision analysis in e-supply chain using fuzzy set approach mainly on the basis of fuzzy reasoning Petry nets has been considered by Gao et al [START_REF] Gao | Intelligent decision making in disassembly process based on fuzzy reasoning Petri nets[END_REF]. The method proposed by Liang [START_REF] Liang | Distribution planning decisions using interactive fuzzy multi-objective linear programming[END_REF] aims at simultaneous minimization of total distribution costs and the total delivery time on the basis of fuzzy available supply, total budget, fuzzy forecast demand, and warehouse space. Chen et al. [START_REF] Chen | A mathematical programming approach to supply chain models with fuzzy parameters[END_REF] suggested an approach to deriving the membership function of the fuzzy minimum total cost of the multi-period SC model with fuzzy parameters. The considered fuzzy production planning models and methods are mainly a single product type and separate production planning model without integration with distribution and inventory problems. Computational intelligence is widely used in economics and finance [Chen [3], Sheen [START_REF] Sheen | Fuzzy financial profitability analyses of demand side management alternatives from participant perspective[END_REF], Zadro et al. [START_REF] Zadro_Znya | Computing with words for text processing: an approach to the text categorization[END_REF]]. Torabi and Hassini [START_REF] Torabi | An interactive possibilistic programming approach for multiple objective supply chain master planning[END_REF] considered a supply chain master planning model consisting of multiple suppliers, one manufacturer and multiple distribution centers. They proposed a method to solve multi-objective linear programming (MOLP) models, named TH. Although many researchers have been devoted to solve production-distribution problems in SC environment, there is a few researches that integrates an aggregate inventory-production and distribution plan in a collaborative manner using fuzzy modeling approaches.

This paper contributes to the literature by presenting a multi objective model with resource constraints and lead times and considering a manufacturer with states which is near to real world rather than other models and using FGP approach for handling the collaborative inventory-production-distribution planning problems SC and presenting a new genetic algorithm approach for constrained problems. Evolutionary algorithms such as genetic algorithm were used to solve combinatorial problems. A Genetic algorithm (GA) based method has been used to develop an efficient solution algorithm by Tasan [START_REF]Tasan:A Two Step Approach for the Integrated Production and Distribution Planning of a Supply Chain[END_REF]. Fuzzy-Genetic approach has been proposed to aggregate production and distribution planning in supply chain management by Aliev et al [START_REF] Aliev | Fuzzy-genetic approach to aggregate production -distribution planning in supply chain management[END_REF]. Many challenges arise when the algorithm is applied to heavily constrained problems where feasible regions may be sparse or disconnected. This study proposes an approach to obtain solutions which are close to the feasible region.

Problem Assumptions

The assumptions to model the problem are as follows:

1. It has been considered a manufacturer with p plants, d distributors, r retailers, and c customers 2. All of the decisions are made within multi-periods. 3. Customers assign cost for backorder as a penalty for retailers. 4. There is transportation capacity constraint for all echelons. 5. Delivery due dates have been assigned by distributors.

Parameters

: Amount of product i demanded by customer c from retailer r in period t.

: Unit production cost of product i.

: Unit sales price for product i from manufacturer to DCs in period t. This included product cost, the cost of transportation, and ordering cost.

: Unit sales price for product i from DC d to retailer r in period t.

: Unit transportation cost for product i from plant p to DC d in period t. DC pay it.

: Unit inventory holding cost of final product i in plant p. : Unit inventory holding cost of final product i in DC d.

: Final product i warehouse capacity in plant p in period t. : Final product i warehouse capacity in DC d in period t. : Final product i warehouse capacity in retailer r in period t. : Unit processing time for final product i.

: Transportation capacity from DC d to retailer r in period t.

: Delivery due date for product i from DC d to manufacturer in period t.

: The time required to ship the products from plant p to DC d.

: Transportation capacity from plant p to DC d in period t.

Decision Variables

: Amount of product i to be transported from DC d to retailer r in period t. : Amount of product i to be transported from retailer r to customer c in period t.

: Amount of product i to be transported from plant p to DC d in period t. : Inventory of product i at the DC d in period t. : Inventory of final product i in retailer r in period t. : Production quantity of product i in plant p in period t.

: The amount of backorder of product i from retailer r to customer c at the end of period t.

: The time in which final product i is maintain in plant p in period t.

The amount of inventory of product i in plant p in period t

Objective functions

Manufacturer Profit :( Maximization)=sales revenue-total manufacturing costtotal inventory types holding cost =

(1)

inventory cost-total transportation cost = - - - (2)
Backorder Level For Retailer r : (Minimization)

= (3) 2.6 Constraints (4) (5) (6)
(4), ( 5), ( 6) state that inventory level in each echelon is restricted by inventory capacity.

Since, distributors set due date for delivering items from manufacturer, thus sum of production time in manufacturer and inventory holding time in plants in each period and delivery time items to distributor, should be less than product delivery due date. Thus we have: [START_REF] Nozick | Inventory ,transportation,service quality and the location of distribution centers[END_REF], mean that the amount of product i to be transported among echelons is limited by transportation capacity.

(7) (8) (9) (8),
(10) (10) is balance equation for DCs; the amount of products that enter to DC d must be equal to the amount of products that leave from and stored at this DC.

Inventory of product i in plant p in period t is equal to inventory of that product in previous period plus production quantity of product i in plant p in period t minus amount of product i transported from plant p to DCs in period t. As shown by ( 11):

(11)
Backorder level of product i incurred by retailer r in period t equals to backorder level of that product in previous period plus total demand of the product by retailer r in that period. This is shown by [START_REF]Tasan:A Two Step Approach for the Integrated Production and Distribution Planning of a Supply Chain[END_REF].

(12)
And finally, the backorder level at the last period should be zero for fulfilling the customer demand:

(13)
All of variables are continuous and positive.

Methodology

The Proposed Genetic Algorithm

In this problem we are dealing with a multiple objective possibilistic linear programming model. To solve this problem, we apply a two-step approach. In the first step, the original problem is converted into an equivalent auxiliary crisp multiple objective linear model. In the second step, a fuzzy goal programming approach which is named TH is used. In this method the crisp multi-objective model convert to a single objective model considering decision maker's imprecise aspiration levels for goals.

To solve the problem, we propose a genetic algorithm (PGA) considering constrained model and compare the results with algorithm which is proposed by Haupt and Haupt [START_REF] Haupt | Practical Genetic Algorithm[END_REF] (HGA). We use continuous genetic algorithm versus binary genetic algorithm, because variables are continuous. For dealing with our constrained model when model's size is large, we propose a genetic algorithm which its solutions are selected from feasible region as far as possible because it is impossible to select all members of population from feasible region. Then we compare obtained results through this method with method which is proposed by Haupt and Haupt [START_REF] Haupt | Practical Genetic Algorithm[END_REF] named HGA. In HGA method, constraints are added to objective function by using penalty coefficients. A constrained model can be stated as follows:

Min f(x) s.t (x)=0 i=1,…,I In majority of algorithms, for generating initial population random numbers are used for generating initial population. While, in a problem which includes constraints in addition to objective functions, using this random numbers cannot imply that initial population has been selected from a feasible region or has minimum violation. Also, initial population is the base for constructing next populations. In genetic algorithm which is presented here, we consider this problem. Also initial solution is constructed with minimization of violation. We do it, using PSO algorithm which is an evolutionary algorithm similar to genetic algorithm but it have operators less than genetic algorithm. Thus, for generating initial population, we minimize below fitness function: Violation= + Another difference between our proposed genetic algorithm and other algorithms is that in this algorithm fitness function is the same as objective function. The method for mating which has been proposed by Haupt and Haupt [START_REF] Haupt | Practical Genetic Algorithm[END_REF] is as follows:

The blending method finds ways to combine variable values from the two parents into new variable values in the offspring. A single offspring variable value, , comes from a combination of the two corresponding offspring variable values = +(1-) Where: = random number on the interval [0, 1], = nth variable in the mother chromosome, = nth variable in the father chromosome. In our proposed genetic algorithm for mating, change while the violation for new offspring is less than the average violation in initial population. Also for mutation and selecting the member which should be affected by mutation ,we continue generating random numbers while interested violation will be occurred, then replace the amount of selected member with the amount of same member in chromosome which has minimum violation.

Analysis of variance

In addition to achievement level, another characteristic which has been considered to compare performance of HGA and PGA is violation. It has been done by analysis of variance (ANOVA). An independent t-test has been conducted to test the difference between mean of violations. It is assumed that: M1: violation which was resulted from HGA M2: violation which was resulted from PGA Analysis of variance was done using Minitab. Thus following 2 tests of hypothesis were performed. Amount of obtained p-value for test of hypothesis 1 is 0.045. Considering, test of hypothesis is performed with 0.95 for confidence level, and p-value for test of hypothesis is less than 0.05, thus, null hypothesis is rejected. It shows that mean of violation in PGA is less than HGA (P-value<0.05).

Numerical Example

To demonstrate the practicality of the proposed model, we considered an assumed SC. In our hypothetically constructed SC, there is a manufacturer company consists of multiple plants, multiple DCs, retailers and customers. First, a problem with a small size has been designed and then results have been compared with Lingo's results. Both genetic algorithms run 30 times and satisfaction degree for each goal is calculated. Then we set:

(Weight of manufacturer)=0.3, (Weight of DCs)=0.3, (Weight of retailers)=0.4. Also, we set =0.5( is coefficient in TH method) i=3, t=4, p=3, d=2, r=3, c=3. We generate all of required parameters randomly. For receiving further information about these random numbers, please contact the corresponding author. To survey the results obtained from Lingo8 and genetic algorithm, a problem with small size has been solved and results have been presented in table1. It is concluded that the average difference between PGA and HGA and lingo is 7% and 10% respectively. Obviously, difference between results obtained from PGA and HGA are not large; thus, methods can be used in problems with large size. Now, consider a large model and set: i=6, t=8, p=5, d=2, r=3, c=3. The satisfaction degree of each goal is shown in table 2; as can be seen, the satisfaction degree for goals in PGA algorithm is more than HGA, and it reveals the efficiency of proposed genetic algorithm.

Conclusions

Managing operations in today's competitive market place poses significant challenges. Based on the traditional thought there were so many conflicts in the multiple demands on the operational functions that trade-offs were made in achieving excellence in one or more of these dimensions.

This paper tackled with integrated inventory-production-distribution planning problem in SC system. A multi-objective linear programming model has been developed in this concern. Decision maker's imprecise aspiration levels for the goals have been incorporated into the model using fuzzy goal programming approach.

Computational experiments have been provided from a case problem. A genetic algorithm has been proposed to solve constrained problem and results have been compared to genetic algorithm suggested by [START_REF] Haupt | Practical Genetic Algorithm[END_REF]. While, in solving problems with constraints there is no guarantee that initial population is feasible or has minimum violation. Proposed Genetic Algorithm, using PSO algorithm, tries to construct initial solution with minimum violation. Also a new mating method has been proposed in our genetic algorithm. In addition we don't use penalty function as fitness function. Numerical results obtained, showed the efficiency of proposed algorithm rather than algorithm used by Haupt and Haupt [START_REF] Haupt | Practical Genetic Algorithm[END_REF]. The paper contributes to literature in designing a multiple objective linear model for integrated inventory-production-distribution planning which is close to real world supply chain and using fuzzy goal programming, also proposing a new genetic algorithm. Analysis of variance has been used to compare mean of violation in HGA and PGA. It is resulted that violation in PGA is less than HGA. Thus, PGA is closer than HGA to feasible solution

  of production items (i=1,…,I) t: index of time periods(t=1,…,T) p: index of plants(p=1,…,P) d: index of DC s(d=1,…,D) r: index of retailers(r=1,…,R) c:index of customers(c=1,…,C)

Table 1 .

 1 : Achievement levels obtained by Lingo, HGA, PGA in small size.

	Achievement	Lingo	HGA	PGA
	Level(%)
	µprofitM	0.85	0.63	0.66
	µDC1profit	0.94	0.75	0.80
	µDC2profit	0.92	0.72	0.76
	µRET1BLG	0.95	0.75	0.79
	µRET2BLG	0.75	0.61	0.69
	µRET3BLG	0.87	0.65	0.71

Table 2 .

 2 : Achievement levels obtained by HGA, PGA in large size

	Achievement	HGA	PGA
	Level(%)
	µprofitM	0.59	0.6
	µDC1profit	0.71	0.7
	µDC2profit	0.68	0.69
	µRET1BLG	0.72	0.74
	µRET2BLG	0.6	0.62
	µRET3BLG	0.67	0.69