Mian Atif Hafeez
email: atifhafeez@qu.edu.qa

Racha Chahrour
email: racha.chahrour@hochtief.de

Vladimir Vukovic
email: v.vukovic@tees.ac.uk

Nashwan Dawood
email: n.n.dawood@tees.ac.uk

Mohamad Kassem
email: m.kassem@tees.ac.uk

Investigating the potential of delivering Employer Information Requirements in BIM enabled Construction Projects in Qatar

Keywords: BIM, EIR, Information Requirements, lifecycle information flow

Employer's Information Requirements (EIR) is a key document for the successful delivery of construction projects using Building Information Modeling (BIM). EIR sets out the information to be delivered and the standards and processes to be adopted by the suppliers as part of their project delivery approach. The concept of EIR has been developed by the UK BIM Task Group as a holistic framework for the UK construction industry to deliver the UK construction client requirements in projects using BIM. It includes a set of requirements and guidelines in three macro areas namely, technical, management and commercial. EIR, which are specific to the construction industry in Qatar, do not exist yet despite BIM is increasingly adopted across the Qatari construction industry. However, construction projects using BIM in Qatar adopts various aspects in technical, management and commercial areas. In this paper, we analyze the current BIM practice in Qatar and compare the findings against the items of the three EIR's areas. The overarching aim is to assess the potential of delivering EIR in BIM based construction projects in Qatar. To accomplish this aim, major construction industry players (clients, consultants, contractors), representing a significant part of Qatar construction industry, were interviewed about the three EIR's areas and their items. The results showed discrepancies in addressing EIR and varied levels of readiness in delivering the different EIR's areas and items. The paper has proposed general guidelines for delivering EIR in Qatar which are informed by the survey and current international EIR standards.

Introduction

Employer Information Requirements (EIR), a terminology developed by the UK BIM Task Group, is a "pre-tender document setting out the information to be delivered, and the standards and processes to be adopted by the supplier as part of the project delivery process" [START_REF] Bsi | PAS 1192-2:2013 Specification for information management for the capital / delivery phase of construction projects using building information modelling[END_REF]. The UK's Publicly Available Standard (PAS 1192) series makes distinction between a 'Client' and an 'Employer'. A client may appoint an employer who is the legal entity named in the contract and responsible for procuring the asset [START_REF] Bsi | PAS 1192-2:2013 Specification for information management for the capital / delivery phase of construction projects using building information modelling[END_REF].

The client is considered to be a body which incorporates the interests of the buyer of construction services, prospective users and other interest groups [START_REF] Kamara | Process model for client requirements processing in construction[END_REF]. The client's decision to commission a project is influenced by organizational factors (e.g. strategic, operational, etc.) that add complexity to the process of defining the requirements of the design phase and other project delivery phases [START_REF] Kometa | Evaluation of Factors Influencing Construction Clients' Decision to Build[END_REF]. Additional project related requirements are related to site selection, environmental considerations, regulatory framework, design specifications, construction process and life cycle performance [START_REF] Kamara | Process model for client requirements processing in construction[END_REF]. The multidisciplinary and fragmented nature of contracted organizations makes it also difficult for project stakeholders to work towards a consistent understanding of client's requirements.

The adoption of Building Information Modeling (BIM) concepts and workflows is proliferating within organizations, through project teams, and across the whole construction industry [START_REF] Succar | Macro-BIM adoption: Conceptual structures[END_REF]. Strategic steps are taken by various governments including UK, Singapore, Finland, USA, among others to encourage the adoption of BIM in their respective AECO industries [START_REF] Kassem | Building Information Modeling: Analyzing Noteworthy Publications of Eight Countries Using a Knowledge Content Taxonomy[END_REF]. Client's requirements should be processed and communicated properly to all project stakeholders throughout the whole project life cycle from the early initiation phase to the handover and operation. Building Information Modeling (BIM) can be a means for project stakeholders to communicate, manage and deliver client's requirements. However, this requires the clear definition of the EIR that sets the processes and standards to be adopted by the suppliers throughout the project life cycle.

While there are no explicit guidelines for defining EIR in Qatar, BIM is increasingly adopted on construction projects. This paper aims to analyze the current BIM adoption in Qatar against the EIR's areas and their items as defined by the UK BIM Task Group. The content outline of the EIR covers three areas and their items include: technical (specification of software platforms, and definitions of levels of detail), management (management processes to be adopted in connection with BIM on a project) and commercial (BIModel deliverables, timing of data drops and definitions of information purposes). More information about the items is included in the subsequent literature review section. Following the literature review, the paper conducts the comparison and discusses the findings.

Literature Review

Client requirements can be described in terms of the objectives, needs, wishes and expectations of the client (i.e., the person or firm responsible for commissioning the design and construction of a facility)" [START_REF] Kamara | Client Requirements Processing for Concurrent Life-Cycle Design and Construction[END_REF]. Client's requirements tend to evolve along the life cycle of the project either due to a change in the client requirements itself or due to adaption of the project to an unintended use [START_REF] Jallow | Life cycle approach to requirements information management in construction projects: State-ofthe-art and future trends[END_REF]. Therefore a requirements management system is needed to cater for these evolving client's requirements.

Requirements Management is also a well-researched area that has been applied to product development industries. "Requirements management is the process of eliciting, documenting, organizing, and tracking requirements and communicating this information across the various stakeholders and the project team" [8]. However much of these studies are not BIM related.

It was proposed that management of requirements should extend beyond elicitation and documentation and requires an approach that will enable changeability and impact analysis, accessibility, traceability and communication to all stakeholders [START_REF] Jallow | Life cycle approach to requirements information management in construction projects: State-ofthe-art and future trends[END_REF]. It was further suggested that there should be a process for client's requirements information management across the whole life cycle and that the requirements and their impact should be tracked throughout whole life cycle of project including Facilities Management (FM) [START_REF] Jallow | Life cycle approach to requirements information management in construction projects: State-ofthe-art and future trends[END_REF].

While project requirements are essential for the physical delivery of the project, with the recent advances in BIM and use of ICT in construction, the information requirements, which present a part of overall client's requirements, are gaining importance. Information is the key component of BIM and needs explicit attention in order to achieve the full potential of BIM across the whole life cycle. Therefore the EIR was introduced to address the information requirements and deliverables the client requires to make effective strategic and operational decisions across a project life cycle. One of the prominent EIR are those proposed in the UK by the BIM Task Group [START_REF]Employer's Information Requirements Core Content and Guidance Notes[END_REF]. They include three areas of requirements with several items as illustrated in Table 1 To deliver the EIR, there are Publicly Available Specifications (PAS 1192-2:2013 [START_REF] Bsi | PAS 1192-2:2013 Specification for information management for the capital / delivery phase of construction projects using building information modelling[END_REF], PAS 1192-3:2014 [START_REF] Bsi | PAS1192-3:2014 Specification for information management for the operation phase of assets using building information modelling[END_REF] and PAS 1192-5:2015 [START_REF] Bsi | PAS 1192-5:2015 Specification for security-minded building information modelling , digital built environments and smart asset management[END_REF]), standards (BS 1192-2:2007 [START_REF] Bsi | BS 1192 : 2007 Collaborative Production of Architectural , Engineering and Construction Information -Code of practice[END_REF] and BS 1192-4:2014 [START_REF]BS 1192-4:2014 Collaborative production of information Part 4 : Fulfilling employer ' s information exchange requirements using COBie -Code of practice[END_REF] ), protocols (i.e. CIC BIM Protocol [START_REF]BUILDING INFORMATION MODEL (BIM) PROTOCOL[END_REF]), classification systems (Uniclass 2015) and technologies (the Digital Plan of Work) that are available for the entire UK construction industry. These specifications, standards, protocols, classification systems and technologies address various aspects of the application of BIM and related issues across the whole life cycle of a project. For example, the PAS 1192-2:2013 [START_REF] Bsi | PAS 1192-2:2013 Specification for information management for the capital / delivery phase of construction projects using building information modelling[END_REF] specifies processes for information management for the capital/delivery phase of construction projects using BIM starting with Plane Language Questions (PLQ) to determine employer's/client's requirements through EIR and BIM Execution Plan (BEP) that specifies collaboration processes along the project life cycle, from the early design until the handover stage. Similarly CIC BIM Protocol [START_REF]BUILDING INFORMATION MODEL (BIM) PROTOCOL[END_REF] addresses issues regarding BIModels including the handling of intellectual property rights (IPR) and certain contractual requirements specific to BIModel at defined stages of projects.

BIM adoption is also increasing in Qatar and is being required by most of the major procurers (e.g. Ashghal, the Public Works Authority, Qatar Rail, Qatar Foundation, etc.). However, in Qatar there is a lack of EIR guidelines. This paper investigates the potential of delivering EIR by comparing current practice against the EIR of the UK BIM Task Group. The ultimate aim is to conduct a gap analysis and suggest recommendations for a Qatari-specific Employer Information Requirements (QEIR).

Methodology

This research adopted qualitative survey-based research approach. Surveys are designed to provide 'a snapshot of things are at a specific time' [START_REF] Martyn | The Good Research Guide -for small-scale social research projects[END_REF]. Surveys can be conducted using either questionnaires or interviews. This research combines a semistructured interview approach with the observation of secondary sources such as invitation to tender documentations. The interviews were conducted in two stages, starting from a less structured first stage to a more structured second stage. Six interviews were conducted in the first stage. The questions evolved during these initial interviews, resulting in a version restricted from further changes. The questions were still kept open ended to allow for interviewees' input beyond the given choices and examples of possible answers. The final version of the interview questions was used to interview additional 22 interviewees. Available invitation to tender documents were also collected and analyzed for getting relevant requirements. United Kingdom (UK) was selected as a benchmark as it is the only country where client's requirements are explicit and considered a cornerstone of the UK BIM policy.

The interviewees included stakeholders from Client (9, 32%), Contractor (5, 18%) and Consultant (14, 50%) organizations working on several ongoing projects in Qatar. The information gathered from the interviews was structured in a way that information can be compared against the areas and items of the UK EIR. Based on the comparison performed and inductive reasoning that caters for the special circumstances of Qatar construction industry (e.g. international companies of varying sizes, with origins from different parts of the world bringing their own perspectives) recommendations were made for a QEIR (Qatar Employer Information Requirements).

Results

Table 1, Table 2 and Table 3 summarize the results from the comparison against the items of the three EIR's Technical, Commercial and Management areas respectively. The EIR items, which were not addressed by the interviewees, are marked as N/A (Not Applicable). The comparison provided in the three tables is detailed and self-explanatory. The first column in each table indicates the item of the EIR which is the subject of investigation. The second column denotes the general requirements for that item as specified within the UK's EIR. The third column includes the finding about that item in Qatar. Finally, the fourth column provides evidence from the interviews that support the finding. The result from the comparison will be discussed in the next section where some general recommendations for QEIR are made.

Discussion and Recommendations

The key distinguishing factors between the EIR guidelines of the UK and BIM current practice in Qatar are in the degree of completeness or coverage of items; the clarity and consistency in the definition of EIR items, and the project stage in which requirements are embedded. In the UK, the PAS 1192-2 requires that design team and contractor team include an outline BIM Execution Plan (BEP) in their proposals at the pre-contract stage to demonstrate their approach to deliver the EIR [START_REF] Bsi | PAS 1192-2:2013 Specification for information management for the capital / delivery phase of construction projects using building information modelling[END_REF]. After the award of the contract, the responsible supply chain needs to develop a detailed BIM execution plan aligned with the EIR.

The EIR items that are included in tender documents in Qatar mainly address a few items of each of the EIR's areas. However, such items are not consistently prescribed and are often interpreted differently by the various project stakeholders.

Under the technical items of the EIR, the Level of Details (LOD) is specified without referring to a specific methodology which sets the incremental development of the LODs. LODs are also often misunderstood by some suppliers or mandated on specific trades (e.g. architectural and structural) involved in a construction project. Software tools are generally not prescribed. However, some large scale projects specify the use of certain design authoring tools and collaboration networks. There are no data exchange format (i.e. neutral format) prescribed across the whole industry but these are usually specified within the protocols developed by the lead consultant or contractor on project. Much of the large-scale projects in Qatar require IFC (Industry Foundation Classes) and 3dPDF.

Within the commercial area of the EIR, BIM capability of organizations is assessed at the pre-qualification phase although they are no standards for BIM capability assessment. It is often assessed based on the number of previous BIM projects undertaken by the suppliers. There are no requirements for the generation of BIM data drops or specific datasets at certain work stages. Several work stages are adopted within Qatar's construction industry including the RIBA Plan of Work, the AIA Phases of Work, and their modified versions by large procurers such as Ashghal (Public Work Agency). The respondents reported circumstances where suppliers working on the same project referred to different project work phases resulting in conflicts and issues that affected the progress of projects.

Under the management area of the EIR, similarly to the project work phases, a combination of standards, protocols and specifications (BS 1192-2, PAS 1192-2, AIA BIM protocols, etc.) are adopted depending on the country of origin of the lead consultant or contractor. Some BIM deliverables such as design coordination (clash avoidance) and 4D and 5D planning are increasingly specified. There are increasing number of projects which require production and site drawings to be produced out of a coordinated model. Also, site inspections, and the consequent authorization of payment, are increasingly conducted within and linked 5D environments. There are no agreed upon definition of BIM roles and their responsibility. The role that is often required by contracts is the "BIM Manager". Finally, there are no clear BIM requirements for the delivery of data to the facility management phase.

The definition of EIR as early as possible in projects, their shared understanding among the supply chain, and the implementation of protocols to deliver them, are key principle for achieving a whole life cycle approach in construction projects. It is clear from the comparison that a whole life cycle approach in Qatar's construction industry is currently not possible. However, in each of the areas of EIR (technical, commercial and management), Qatar's construction industry exhibits capabilities in several items. To build upon current capabilities and build the foundation for the industry to start moving towards a more diffused and mature adoption of BIM, there is a need to develop Qatar Employer Information Requirements (QEIR). The QEIR may require adjustments depending on asset type, project stages, project needs, procurements strategy, IT requirements, terminology, and detailed technical information requirements. This is also important as several large employers and clients have started in recent year hiring consultants to define their EIR and roll them out on their projects as it was observed during the interviews. Over time this will result in several competing commercial, technical and management requirements. Therefore, regarding the general requirements for the definition of guidelines for QEIR, it is important to ensure that they:

• Are adequately generic so that can be adopted across different projects and employers and are un-biased towards current technologies or/and processes; • Are defined based on sufficient knowledge of employer's internal processes;

• Are related roles and responsibilities at employer's organization or agree on a specific changes to current roles; • Build up a BIM team at employer's side to supervise the EIR compliance;

• Consider applicable standards in Qatar, e.g. QCS and to evaluate the applicability of international BIM/information standards; • Clarify the interactions with other management systems within employer organizations; • Clarify model ownership and intellectual property issues, and • Include definition of BIM related terminologies to avoid misunderstanding among project stakeholders. In addition to above general guidelines, a self-explanatory list of recommendations is included in Table 4, Table 5 and Table 6 representing specific recommendations for the items of the three areas of EIR Guidelines.

Table 4: Recommendations for the technical area of the QEIR

Item Recommendations

Software Platforms

Should not be dictated by the employer unless the project is at later stage and models are already produced in specific software tools. However as the employers in Qatar are often dealing with multiple mega projects, a clear strategy is required to clarify how to deal with deliverables prepared in various software packages. Viewer software at employer's offices may require specific exports format too. At minimum software should be clarified in contractor's BEP and is subject of approval. The employer's choice of document management system (DMS) should be communicated to the supply chain to get consistent and seamless submissions.

Data Exchange Format

Beside the native format, neutral data formats should be made available such as IFC or PDF. However the information content in case of IFC should be verified. As several projects are infrastructure and utilities, the Centre for Geographic Information Systems (CGIS) needs should be considered in the QEIR.

Co-ordinates

Qatar National Grid (QNG) and QND (Qatar National Datum), origin and units as a minimum

Level of Detail

Level of Detail for geometry (LOD) and Level of Information (LOI) including clarification on evolution along the project work phases. A model element matrix should be requested for all project phases to describe LOD and LOI in more detail. LOD should be defined to serve the purpose of models as unnecessary detailed geometry will affect the performance. LOI should be also planned carefully to serve decisions along the project work phases and the O&M requirements.

Training

Areas of training covering different types of competencies should be specified and suppliers should demonstrate their training plan in these areas.

Clients Strategic Purpose

The overall purpose of the employer mandating BIM should be made clear in the contract. Also the purpose of each required BIM process should be addressed. This will help contractors/consultant to understand the scope and utilization of their deliverables.

BIM-specific competence assessment

There is a need to develop a competency based system for the BIM roles (e.g. BIM Manager) in Qatar and a system to assess the BIM capability of organization. QEIR could require the project staff and their organizations with this system. .

Table 5: Recommendations for the management area of the QEIR Item Recommendations

Standards

There is a need to develop BIM standards/guidelines and protocols for Qatar's construction industry. Such standards should be structured by BIM use. A suitable classification system should be adopted. National BIM protocols or BIM Execution Protocols (BEP) and templates should be developed. Also the codifications/naming dictated by specific standards at file level should be compared with existing CAD and documents naming defined in DMS in case there is no overall information requirements established. This is very important in large scale projects.

Roles and Responsibilities

Specific roles and responsibilities related to BIM should be included in the QEIR. Minimum qualification and experience in previous projects for the key BIM personnel is also recommended. A role specific assessment system for assessing BIM personnel should be developed.

Planning the work and Data Segregation

The EIR should clarify model management, folder structure and collaboration environment (Common Data Environments) according to project needs. It is recommended to define how and when models and information will be published to the employer. This should reflect the employer's DMS and internal processes, review, monitoring and reporting periods.

In mega projects, where several contractors are involved, it is important that the QEIR defines a common model breakdown and clear zoning strategy.

Security

Depending on how information will be published to employer, security requirements should be included. There could be special security for certain data with high level of confidentiality and the importance.

Coordination and Clash Detection process

The QEIR should require the specification of software involved, clash matrix and settings at different stages, the coordination process workflow including frequency, meetings and client presentations. Also the description of quality procedure and the reporting on clash status should be requested as part of QEIR.

Collaboration Process

Mandate that suppliers adopt a Common Data Environment (CDE) and define how information will be managed among them and shared with the employer

Health and Safety and Construction Design Management

It is recommended to collect H&S related information at defined data drops. Specific presentations could be requested to clarify safety issues or resolutions strategies with BIM support.

System Performance

Employers could make restrictions according to their specific in house applications, e.g. model size and formats, software and versions and model viewer capabilities.

Compliance Plan

QA/QC procedures should be mandated to ensure quality of information and models.

Delivery Strategy for Asset Information

This area has not been addressed with adequate details in the interviews. It was only identified that COBie is mandated on many projects in Qatar. COBie could be used as a data structure to convey data for the O&M Phase. However, it respondents in Qatar reported interoperability issues with their FMS and lack of understanding in this area.

Management Instruments

Further management instruments should be addressed, especially drawings and models registers that should be submitted regularity to show status. Also clear strategies on how to progress model elements between project phases -i.e. design, construction and as built, including ownership -is required.

Processes

Further BIM supported processes e.g. progress monitoring, payments procedures, cost control, interface management, site logistics, etc. should be addressed in the QEIR.

Conclusion and Limitations

This paper analyzed the potential of delivering EIR in Qatar using the EIR guidelines of the UK BIM Task group. The results showed that the construction industry in Qatar has certain capabilities in several items under each of the three areas of EIR (technical, commercial, management). However, there are significant challenges related to the lack of Qatari-specific BIM standards, BIM dictionary, project work phases, capability assessment, etc. Based on the gap analysis conducted, the research suggested the development of Qatar Employer Information Requirements (QEIR) and some recommendation for its various items.

The limitation of this study is related to the inconsistent coverage of all items of EIR in the interviews. Also the interviews were conducted with relatively large organizations working on large projects. Therefore, the results of the study may be skewed towards larger stakeholders, which however, represent the largest share of the Qatari construction market.

Finally, the outcomes from this research aim to instigate Qatar's construction industry stakeholders to work towards the development of QEIR by proposing this seed of recommendations as the starting point for this discussion.

Table 1 .

 1 . EIR Guidance notes by BIM Task Group

	Technical	Management	Commercial
	1. Software Platforms	1. Standards	1. Data drops and project
	2. Data Exchange Format	2. Roles and	deliverables
	3. Co-ordinates	Responsibilities	2. Clients Strategic
	4. Level of Detail	3. Planning the work and	Purpose
	5. Training	Data Segregation	3. Defined BIM/Project
		4. Security	Deliverables
		5. Coordination and Clash	4. BIM-specific
		Detection process	competence assessment
		6. Collaboration Process
		7. Health and Safety and
		Construction Design
		Management
		8. System Performance
		9. Compliance Plan
		10. Delivery Strategy for
		Asset Information

Table 1 : Technical items of EIR

 1

	Item	Employer	Client Information	Frequently
		Information	Requirements in	Reported issues
		Requirements	Qatar	by Interviewees
		guideline UK
		Should not be		Difficulty in
		Mandated except		exchanging
		those for		information due to
	Software	collaboration,	Not prescribed in	interoperability
	tools	information	most cases	issues. The use of
		exchange and		specific tools is
		Facility Management		prescribed in some
		Requirement		projects..
	Data Exchange Format	Define formats to deliver data at data drops	Mostly Specified	Data Loss in exchange
	Coordinates	Adopt Common Coordinate system for spatial coordination	Specified using local systems such as Qatar National Grid (QNG) and QND (Qatar National Datum	Qatar National Grid (QNG) and QND (Qatar National Datum are used.
	Level of Detail / Level of Development	Levels of Details to be aligned with Stages	Required but inconsistent with no clear definition	Lack of common understanding about what LODs mean
	Training	Specify Training Requirements for bidders and from bidders	Not Specified explicitly. Mostly Ad-Hoc.	There is more demand for BIM training but limited supply (training providers)

Table 2 : Commercial items of EIR Item Employer Information Requirements guideline UK Client Information Requirements in Qatar Frequently Reported Issues by Interviewees

 2

	Data drops	Communicate	Not clearly defined	The information
	and project	the content of		deliverables or data
	deliverables	data drops and		drops are not clearly
		their alignment		defined and cause
		with work stages		misunderstanding among
				stakeholders.
	Clients	Communicate	The existing	Clients require certain
	Strategic	the purpose of	information	BIM deliverables
	Purpose	Client's	requirements do not	without having clear
		information	clearly state the	intention for those
		requirements	purpose for which it	deliverables
		and deliverables	will be used

Table 3 : Management items of EIR

 3

	Item	Employer	Client Information	Frequently
		Information	Requirements in	Reported Issues
		Requirements	Qatar	by Interviewees
		guideline UK
	Standards	Define BIM	There are no Qatari	64% of
		standards	specific BIM	interviewees
		incorporated into	standards. A	reported BIM
		information	combination of	standards are
		requirements	international	required by
			standards is used	contracts.
			and is often required	Both clients and
			by contract.	suppliers have
				different preference
				for BIM standards
				because of the
				availability of
				several standards
				and their countries
				of origin.
	Roles and	Allocate roles	BIM specific roles	Lack of industry
	Responsibilities	associated with the	are required but both	wide agreement
		management of the	role names and	over the job
		model and project	responsibilities are	description of a
		information	not consistently	BIM Manager. The
			used.	job profile for BIM
				managers is not
				known.
	Planning the	Set out requirements	N/A	N/A
	work and Data	for the bidder's
	Segregation	proposals for the
		management of the
		modeling process
	Security	Communicate Client	N/A	N/A
		specific security
		measures for data
		security
	Coordination	Define Coordination	Coordination or	71% of
	and Clash	process along with	clash detection is	interviewees
	Detection	quality control	used on almost all	reported use of
	process	requirements	BIM projects.	software for

Table 6 : Recommendations for the commercial area of the QEIR Item Recommendation

 6 It is recommended to clearly define deliverables at specific data drops. The latter should be also aligned with project stages and linked to other projects deliverables. It should be also made clear which employer's processes the BIM deliverables are supporting at each stage. A pre submission presentation or workshop can facilitate and speed up the approval process.

	Data drops and
	project
	deliverables

Acknowledgement

The work described in this publication was part of the research project funded by the National Priority Research Program NPRP No.: 6 -604 -2 -253.


Aryani Ahmad Latiffi
email: aryani@uthm.edu.my

Juliana Brahim

Mohamad Syazli Fathi

Roles and Responsibilities of Construction Players in Projects Using Building Information Modeling (BIM)

Keywords: Building Information Modeling (BIM), Roles, Responsibilities, Construction Player, Construction Projects

Building Information Modeling (BIM) has been implemented in construction projects to overcome problems such as project delay, cost overrun and poor quality of project. BIM enhances construction player to perform their activities in effective and efficient through the development of three dimensional (3D) model. However, BIM requires changes in current practices among construction players in terms of the processes and technology that use for managing projects. Therefore, this paper is aimed to discuss on roles and responsibilities of construction players in projects using BIM. This is a review paper that discusses on BIM, its definition, activities with roles and responsibilities of construction players in managing projects. The findings revealed that roles and responsibilities of construction players in projects using BIM are differ from conventional practice by the use of BIM tool. The findings of this paper provide useful information for construction players that considering implementing BIM in projects.

Introduction to Building Information Modeling (BIM)

The concept of Building Information Modeling (BIM) has been introduced in the Architecture, Engineering and Construction (AEC) industry to overcome problems in construction projects [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Latiffi | Building Information Modeling (BIM): Application in Malaysian Construction Industry[END_REF]. BIM is said as a new methodology to improve construction projects by the use of BIM tool [START_REF] Latiffi | The Development of Building Information Modeling (BIM) Definition[END_REF]. The use of BIM significantly has increased across the projects life cycle from design to the operation and maintenance of the projects [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Latiffi | Building Information Modeling (BIM): Application in Malaysian Construction Industry[END_REF][START_REF] Latiffi | The Development of Building Information Modeling (BIM) Definition[END_REF][START_REF] Azhar | Building Information Modeling (BIM): A New Paradigm for Visual Interactive Modeling and Simulation for Construction Projects[END_REF][START_REF] Azhar | Building Information Modeling (BIM): Trends, Benefits, Risks, and Challenges for the AEC Industry[END_REF].

Each of construction player uses BIM for different purposes. BIM helps client to understand more on projects' need [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Azhar | Building Information Modelling (BIM): Now and Beyond[END_REF][START_REF] Bryde | The Project Benefits of Building Information Modelling (BIM)[END_REF][START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF]. While architect and engineers use BIM for analyzing and developing projects design. Meanwhile, BIM helps contractor to manage the construction activities and scheduling by using four-dimensional (4D) model. Quantity surveyor (QS) uses BIM to produce an accurate project cost estimation [START_REF] Azhar | Building Information Modeling (BIM): Trends, Benefits, Risks, and Challenges for the AEC Industry[END_REF][START_REF] Nagalingam | Building Information Modelling and Future Quantity surveyors Practice in Sri Lanka Construction Industry[END_REF] and facility manager uses BIM for managing the operation and maintenance of the facility [START_REF] Azhar | Building Information Modeling (BIM): Trends, Benefits, Risks, and Challenges for the AEC Industry[END_REF][START_REF] Bryde | The Project Benefits of Building Information Modelling (BIM)[END_REF]. In order to get the benefits offered by BIM, construction players need to aware on the changes in current practices and the use of information needed in projects using BIM. Therefore, this paper is aimed to explore on the roles and responsibilities of construction players in projects using BIM.

Methodology

A literature review was conducted to explore and discuss on the roles and responsibilities of construction players in projects using BIM. All information related to BIM was gathered from journal articles, international conference papers, books and material available from the internet. Results and findings from the literature review are now discussed.

Roles and Responsibilities of Construction Players in Projects

Using BIM Construction players use BIM to achieve better integration of project information, construction process improvement and to enhance collaboration among them from the early phase of projects [START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF]. Therefore, the use of BIM definitely changed the roles and responsibilities of construction players [START_REF] Gu | Understanding and Facilitating BIM Adoption in the AEC Industry[END_REF][START_REF] Porwal | Building Information Modeling (BIM) Partnering Framework for Public Construction Projects[END_REF]. The literature review on roles and responsibilities of construction players in projects using BIM identifies the activities that need to be conducted by them. Table 1 shows roles and responsibilities of construction players in projects using BIM. To put the information of building into the 3D model for the purpose of FM.

Client

Client or known as an owner is the person or organization that responsible for the cost of projects and get the benefits from the completed projects [START_REF] Gould | Construction project management[END_REF]. In project using BIM, client uses BIM to streamline the delivery of higher quality with better performing building [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF]. Therefore, BIM helps client to increase building performance through the use of BIM-based energy and lighting design, reduce financial risk by obtaining earlier and reliable projects cost estimates and improves collaboration of project team [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF].

In order to get the benefits of using BIM, client should concentrate on the efforts to define the process of using BIM in projects [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF]. This is important for determining the success of using BIM in projects [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF]. Client should specify the method of using BIM and the level of detail of the model in order to develop BIM requirement. This is because, if the BIM requirement are too broad, the outcome from using BIM will be broad and will not meet client expectation. Hence, it is vital for client to determine the deliverables based on the requirement, so that the client could lead the process and get the benefit of using BIM [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF].

Architect

Architect is the principal designer in most of construction projects [START_REF] Gould | Construction project management[END_REF]. Architect is responsible to translate and develop the design concept based on the client's requirement. The roles of architect in project using BIM are to develop conceptual design, detail design and design analysis as well as to develop construction-level information [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF][START_REF] Becerik-Gerber | Building Information Modeling in Architecture, Engineering, and Construction: Emerging Research Directions and Trends[END_REF]. Conceptual design is a basic framework of design that brings all aspects of the project in terms of its function, cost, construction methods, materials, environmental impact as well as aesthetic considerations. The architect uses BIM tool such as Revit Architecture to perform conceptual level design. Based on the figure, architect develops conceptual design to explore early design concepts before creating details of project model. Revit Architecture automatically helps architect to build a parametric framework around the most complex forms and giving greater levels of creative control, accuracy and flexibility [15]. In addition to that, architect could convert any individual face of building masses into building components such as walls, roofs, floors and curtain system [START_REF]Cadalyst, 1-2-3 revit:BIM Concept to Completion[END_REF]. Moreover, Revit Architecture could also maintain the relationship between conceptual model geometry with building component.

As soon as the conceptual design is established, the architect will develop design analysis [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF]15]. It is a measure of physical parameters that can be expected in the real building. It covers on the functional aspect of building performance, temperature and ventilation air flow [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Becerik-Gerber | Building Information Modeling in Architecture, Engineering, and Construction: Emerging Research Directions and Trends[END_REF]. The information regarding the building component in the model is used to conduct an analysis.

Fig. 2 Design Analysis on Sustainability of Building using Revit [15]

Figure 2 shows the example of design analysis to determine whole building energy, day lighting, water and carbon emission analysis based on the conceptual design [15]. By using BIM tool, it allows architect to analyze the location of building that could contribute to the use of electricity and water usage cost. This activity is concerned with collaboration and coordination of other construction players such as civil and structural engineers (C&S Engineers) as well as mechanical, electrical and plumbing engineers (MEP Engineers) as the analysis will be made by using technical information from other players [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF].

The role of architect in project using BIM also to produce construction documents. This process involves the integration of design and construction. The architect should determine the level of detail required in the model before proceeds for construction of documents [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF]. The architect uses BIM tool for placement and composition rules so that it can expedite the generation of standard construction documentation. Therefore, the use of BIM tool helps architects to speed the production of documents in more efficient.

Engineers

Engineers are also known as professional designer that design the projects [START_REF] Gould | Managing the Construction Process[END_REF]. The engineers can be categorized into civil and structural (C&S), mechanical, electrical and plumbing (MEP) [START_REF] Becerik-Gerber | Building Information Modeling in Architecture, Engineering, and Construction: Emerging Research Directions and Trends[END_REF]. The C&S and MEP engineers use BIM tool such as Revit Structural and Revit MEP to develop design analysis coordination process. Based on the figure, C&S and MEP engineer use BIM tool to view different structural systems and alternate design option within the same digital model. Any changes made on the design will automatically coordinate the changes across other representation of the projects. In addition to that, by using BIM tool, they could create shop drawings, fabricate and installing C&S and MEP systems in more accurate [START_REF] Dossick | Messy Talk and Clean Technology: Communication, Problem-Solving and Collaboration Using Building Information Modelling[END_REF]. The shop drawings also contain details of the items that will be manufactured, purchased and installed [START_REF] Dossick | Messy Talk and Clean Technology: Communication, Problem-Solving and Collaboration Using Building Information Modelling[END_REF].

Contractor

A contractor is a person that has a contract with a client and responsible for the construction of a project [START_REF] Gould | Managing the Construction Process[END_REF]. In projects using BIM, contractor develops digital model using BIM tool such as Naviswork for identifying any design issues before the construction take place [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Azhar | Building Information Modeling (BIM): Trends, Benefits, Risks, and Challenges for the AEC Industry[END_REF][START_REF] Azhar | Building Information Modelling (BIM): Now and Beyond[END_REF]. With the digital model, the contractor could simulate the process; identify construction outcomes, any problems that affect cost, schedule and quality of projects [START_REF] Reddy | BIM for Building Owners and Developers: Making a Business Case for Using BIM on Projects[END_REF]. Figure 4 shows the construction planning and scheduling using 4D model.

Fig. 4 Construction Planning using 4D model [15]

Based on the figure, the contractor uses BIM to conduct an analysis to see the performance levels and requirement such as structural loads, maximum shear and moments [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Hardin | BIM and Construction Management: Proven Tools, Method and Workflows[END_REF]. This analysis is vital to ensure the constructability of the projects [START_REF] Azhar | Building Information Modeling (BIM): Trends, Benefits, Risks, and Challenges for the AEC Industry[END_REF][START_REF] Hardin | BIM and Construction Management: Proven Tools, Method and Workflows[END_REF]. The contractor could also prepare the schedule of work as well as to track the progress of work [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Azhar | Building Information Modeling (BIM): Trends, Benefits, Risks, and Challenges for the AEC Industry[END_REF][START_REF] Bryde | The Project Benefits of Building Information Modelling (BIM)[END_REF][START_REF] Hardin | BIM and Construction Management: Proven Tools, Method and Workflows[END_REF]. The status of each of component is added into a digital model for easier coordination. Then, the model could perform sequence of the work with and without appearance of facilities such as crane [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF]. From the digital model, the contractor also capable to extract counts of components, area, volumes of spaces, material and quantities for producing project cost estimates [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF].

Quantity Surveyors (QS)

Quantity Surveyor (QS) is a person that is responsible to perform financial control, cost and contractual administration of project [START_REF] Nagalingam | Building Information Modelling and Future Quantity surveyors Practice in Sri Lanka Construction Industry[END_REF]. A QS uses BIM-based quantity taking off to eliminate errors in conventional quantity taking off [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF][START_REF] Monteiro | BIM Modeling For Contractors-Improving Model Takeoffs[END_REF][START_REF] Monteiro | A Survey on Modeling Guidelines for Quantity Takeoff-oriented BIM-based Design[END_REF]. Figure 5 shows taking off from the digital model. Fig. 5 Taking off using Vico [START_REF] Nomitech | [END_REF] By using BIM tool such as Vico [START_REF]VicoSoftware[END_REF], QS could perform automatic quantity taking off with automatic extraction of visual information such as floor plan, elevation, 2D and 3D sections including quantities, model analysis and simulation results [START_REF] Monteiro | A Survey on Modeling Guidelines for Quantity Takeoff-oriented BIM-based Design[END_REF]. BIM tool has a feature that link to items and assemblies annotate the model as well as create a visual takeoff diagram. However, this application requires collaboration of other construction players such as architect and engineers while developing the model [START_REF] Sattineni | Estimating with BIM: A survey of US construction companies[END_REF]. This is because, the accuracy of project cost estimating, count and measurement are highly depending on the developmental digital model by architect and engineers [START_REF]VicoSoftware[END_REF][START_REF] Sattineni | Estimating with BIM: A survey of US construction companies[END_REF].

Facility Manager

Facility Manager's role is closely related to the project conception and planning for future facility's need [START_REF] Gould | Managing the Construction Process[END_REF]. Facility manager uses BIM to leverage facility data that provide safe, healthy, effective and efficient work environment [START_REF] Jordani | BIM and FM: The Portal to Lifecycle Facility Management[END_REF][START_REF] Lavy | A Case Study of Using BIM and COBie for Facility Management[END_REF]. Fig. 6 Information of the Facility in Digital Model [START_REF] Lavy | A Case Study of Using BIM and COBie for Facility Management[END_REF] Based on Figure 6, the information in the building model associated with spaces, masses, construction level details, scope of the model (such as architectural and details of MEP elements) and facility assets [START_REF] Eastman | BIM Handbook: A Guide to Building Information Modelling For Owners, Managers, Designers[END_REF]. The information is vital for future analysis, assets tracking as well as future maintenance schedule. Facility manager will obtain the information of the building from the contractor, so that facility manager could track any components in the building, identify any inefficiencies of building operations. As a result, facility manager could respond immediately to client based on the information in the building model [START_REF] Lavy | A Case Study of Using BIM and COBie for Facility Management[END_REF].

Discussion

This paper is the fundamental for construction players to shows the roles and responsibilities of construction players in projects using BIM and how it differ from conventional practice. Figure 7 has been created based on the information on the roles and responsibilities of construction players in projects using BIM which has been discussed in this paper.

Fig. 7 Differences of Relationship of Construction Players between Conventional

Practice and Project Using BIM.

Figure 7 shows the similarity of roles and responsibilities of construction players in conventional practice and projects using BIM. However, the difference of practices is the use of technology, which is BIM tool for developing projects information into digital models. The use of BIM tool helps construction players to conduct their roles and responsibilities in more efficient and effective by overtake the traditional 2D paper-based of managing project information into virtual digital model and also allow to have collaboration and communication among construction players. Compare to traditional way of working in conventional practice, construction players normally working independently without coordination of their work with other players, prone to errors in managing project information and lead to delay making a decision. By using BIM, collaboration and communication among construction players could happen as they work in a coordinate way in developing project information into digital models. The construction players could give immediate feedback and decision regarding the projects information. Consequence to that, they could improve project design, producing accurate project cost estimation, better work integration and facilities.

Conclusion and Further Work

The use of BIM has given benefits to construction players in improving their roles and responsibilities in construction projects. However, they should be aware on the changes of practices so that they could gain the benefits. Further work will be conducted with construction players that involves in projects using BIM to explore more on their current practices in projects using BIM.

  Figure. 1 shows the example of conceptual design using Revit Architecture.

Fig. 1

 1 Fig. 1 Conceptual Design by using Revit [15]

Figure 3 (

 3 a) and (b) show example of design analysis for C&S and MEP engineers.

Fig. 3 (

 3 Fig. 3 (a) Examples of Design Analysis for C&S [15]

Table 1 . Roles and Responsibilities of Construction Players No. Construction Player Role and Responsibilities of Construction Players in Project using BIM

 1

	1	Client/Owner	•	Defining a suitable method of using BIM
	2	Architect	•	To develop conceptual design.
			•	To develop detail design and analysis.
			•	To develop construction level information
			•	To develop construction documents.
	3	C&S and MEP	•	To develop detail design.
		Engineer	•	To develop shop drawings with detail elements.
	4	Contractor	•	Perform constructability analysis
			•	Scheduling and planning using 4D model
			•	Produce cost reliability

Table Cont' No. Construction Player Role and Responsibilities of Construction Players in Project using BIM

	5	Quantity Surveyor (QS) •	To extract quantities and produce cost estimation
				from the 3D model
	6	Facility Manager	•

Acknowledgement

The authors would like to thank to Ministry of Education of Malaysia (MOE), and Office of Research, Innovation, Commercialization and Consultancy (ORRIC), UTHM for supporting this research under the Exploratory Research Grant Scheme (ERGS), (Vote No. E029).


Haiqing Zhang
email: haiqing.zhang.zhq@gmail.com

Aicha Sekhari
email: aicha.sekhari@univ-lyon2.fr

Florendia Fourli-Kartsouni

Yacine Ouzrout
email: yacine.ouzrout@univ-lyon2.fr

Abdelaziz Bouras
email: abdelaziz.bouras@qu.edu.qa

Customer Reviews Analysis Based on Information Extraction Approaches

Keywords: Information Extraction, TF-IDF, Opinion Mining, Dependency Relations, Part-of-Speech

The existing information extraction approaches are generally analyzed and then categorized into several groups based on the superiority and the intelligence of the approaches as well as their capability to solve complex problems. Two practical approaches are provided to clarify how to use the information extraction solutions to obtain the valuable information from numerous reviews. The first approach is to support the front-end services in the EASY-IMP project. The customer preference and the optimum interest of customers is determined based on TF-IDF approach. Roughly 100,000 pages have been analyzed and the customer preference is studied based on the most relevant keywords. However, TF-IDF approach limits on the capability to provide the personalized infromation, which can only obtain the restricted information based on weights calcualtion. In order to extract more efficient customerized infromation, an opinion mining algorithm is proposed. The proposed algorithm aims to obtain sufficient information extraction results and reduce the complexity and running time of information extraction by jointly discovering the main opinion mining elements. The analyzed reviews show that the proposed algorithm can effectively and simultaneously identify the main elements.

Introduction

EASY-IMP 1 project is founded to develop methodologies, tools, and platforms for design and production of personalized meta-products by combining wearable sensors embedded into garment based on mobile and web-based technologies. A meta-product means a customer driven customizable entity that integrates sensory and computing units, leading to a paradigm shift from mass production to intelligent, over-the-web configurable products. The widely used Web communication on mobile and web-based technologies in this project has dramatically changed the way individuals and communities express their opinions on meta-products. More and more reviews are posted online to describe customers' opinions on various types of products. These reviews are fundamental bits of information to support both firms and customers for making correct decisions. The features and attributes of a product extracted from online customer reviews can be used in recognizing the strengths and weaknesses of the heterogeneous products for firms. While customers do not always have the ability to wisely choose among a variety of products in the market, they commonly seek product information from online reviews before purchasing a new product. Moreover, the number of reviews grows rapidly, which becomes impractical if analyzing the reviews by hand. If features and the related opinions can be obtained from the massive reviews and then firms will gain great benefits by using the extracted information to evaluate how and where to improve the product through the product development process. Hence, in this paper, we have studied the information extraction approaches to analyze the reviews of meta-products.

The information extraction (IE) task is to identify the entities, relations between objects, and obtain the relevant features of the identified entities. Based on [START_REF] Mccallum | Information extraction: Distilling structured data from unstructured text[END_REF], The IE tasks are categorized in five groups in terms of segmentation, classification, association, normalization, and de-duplication. In order to extract the structured data from haphazard, noisy, and unstructured data to complete the IE tasks, the research works also adopt the previous techniques such as machine learning, data mining, information retrieval, and computer linguistics to solve the IE tasks.

However, fully addressing IE is a tough problem that the existing proposed algorithms can only solve a small part of IE tasks from the emergence of IE till now. In order to better comprehend the advantages and the capabilities of IE, we will give two practical applications by adopting IE solutions. This paper is structured in the following way: A brief study and categorize the existing IE solutions in section 2. Section 3 provides an application that comes from EASY-IMP project, which supplies end-user services based on the TF-IDF (Information Retrieval) approach. In order to more intelligently and more automatically extract the customer information from the reviews, section 4 proposed an opinion mining extraction algorithm to jointly extract features, opinions, and feature-opinion relations to reveal the strengths and weaknesses of the products' attributes; meanwhile, some extracted information is given based on the proposed algorithm. Section 5 concludes the work.

Literature Review

2.1

The Representative Approach of Information Retrieval: TF-IDF

The traditional techniques of IE mainly refer to information retrieval techniques, which are based on key word searches to figure out the most likely document or term by the searcher. In order to complete this task, the weights of the documents must be calculated to answer which one can best satisfy the searching query. The methods are used to assign the weights of terms are Binary Weights [START_REF] Salton | Extended Boolean information retrieval[END_REF], Raw term frequency (Paltoglou and Thelwall, 2010), TF-IDF (Term Frequency-Inverse document frequency) [START_REF] Hiemstra | A probabilistic justification for using tf$\times$ idf term weighting in information retrieval[END_REF], etc. Particularly, TF-IDF is the most commonly used method for web search tasks that orders the documents or terms based on the relevance to the searched query. Therefore, we will give a detailed explanation of TF-IDF. Term frequency (tfxi) is used to measure the term density in a document (Dx), which means the frequency of term Ti in document Dx. Inverse document frequency (IDF) is used to measure the discriminating ability of a term, which means the rarity of the term across the whole documents. Based on [START_REF] Aizawa | An information-theoretic perspective of tf-idf measures[END_REF], the theoretical justification of TF-IDF shows that the optimal calculation of IDF for document retrieval is:

log ti ti n idf df   =     (1)
Where, n is the total number of collected documents, dfxi is the total number of collected documents (Dt) that contain searched term Ti. And then, the formula that is used to express the term weights obtained by TF-IDF is shown as follows:

log ti xi xi ti xi n w tf idf tf df   = × = ×     (2)
For instance, the term frequency tables for two documents are shown in Table 1. Then the calculation of tf-idf for two terms "Cricket" and "Grappling" is given in the following:

Cricket 2 (D1) 2 log 1 0 0 2 xi ti w tf idf   = × = × = × =     (3) Grappling 2 (D2) 4 log 4 log 2 1.2040 1 xi ti w tf idf   = × = × = × ≈     (4)

Morden Information Extraction Solutions

The modern information extraction solutions differ from the traditional techniques that extract the most important facts about features, entities, and relations from various documents (which may be combined by multiple languages). The obtained important facts are usually used to analyze the changing trend of reviewers' preference and recommendation, the summary of the document, and serve the new products development.

The Proposed Front-End Services for EASY-IMP Project Based on TF-IDF Approach

A number of web-based services have been developed based on the EASY-IMP project. The users can build the profiles, discover the most suitable Meta-Products (MP) based on the related requirements, and then configure the MPs based on the customer preferences. In order to overcome the challenges related to the complexity and the creativity of the MPs, the front end services are provided to support customer profile building and personalized recommendation based on TF-IDF approach. The modules of the provided front-end services are briefly shown in Figure 1.

The front end services focus on developing the parts of 'user profiling' and 'MP recommendation'. In order to more accurately reveal the user preference, the information including user interests and product preferences should be obtained. Once the basic user information has been retrieved, the user preferences are determined by the frequent items that have been predefined in a list of keywords with respect to a specific subject. The keywords in the social media are automatically generated through analysis of a large corpus of Facebook pages that related to the defined subjects, and the most relevant keywords are identified and selected as the preferred. Roughly 100,000 pages related to the topics of 'Fitness', 'Exercise', 'Running', and 'Cycling' have been obtained by using the Facebook Graph API. Text processing approaches have been used to do preprocessing. TF-IDF is adopted to calculate the relevance weights among words.

In short summary, the EASY-IMP front-end services have been created to provide the useful information about MPs development. The user profiling is built based on basic user information and the inferred user interests. The analyzed 100,000 Facebook pages has proved that the word weight determination base on TF-IDF approach can provide a list of meaningful keywords for accurately classifying new pages based on the predefined user preferences.

The Proposed Opinion Mining Extraction Algorithm to Jointly Execute Opinion Mining Extraction Tasks

Information Extraction Sextuple

On the basis of keywords retrieval, in order to more intelligently discover the customers' preferences, more useful information will be obtained. The essential elements of customer reviews contain the features, with the opinion it expresses, and the relations between features and opinion expressions. The necessary information of reviews is defined as a quintuple in (Liu and Zhang, 2012), we extend the quintuple into a sextuple by adding the relations among features and opinions, which is shown as (ei, fij, ooijkl, rijkl ,hk, tl), where ei is the name of an entity; fij is a feature of ei; ooijkl is the opinion expression on feature fij of entity ei; rijkl is the sets of feature-opinion relation extraction, feature-feature relation extraction, and opinion-opinion relation extraction; hk is the opinion holder; and tl is the time when the opinion is expressed by hk. This definition can provide a basis for transforming unstructured text to structured data in the following sections. The added attribute rijkl can be used to summarize the overall attitude of the whole review and reflect the opinions with respect to a specific feature.

Information Extraction Rules Defined Based on Dependency Relations

The extraction is mainly between features and opinion words. For convenience, some symbols are defined to be able to reuse them easily. The relations between opinions and features are defined as FO↔Rel, between opinion words themselves are OO↔Rel, and between features are FF↔Rel. Six basic extraction tasks are defined to separate information extraction: [START_REF]Mining Text Data[END_REF]. Extracting products' features by using opinion words (FO↔Rel); [START_REF] Aizawa | An information-theoretic perspective of tf-idf measures[END_REF]. Retrieving opinions by using the obtained features (OF↔Rel);

(3). Extracting features by using the extracted features (FF-Rel); (4). Retrieving opinions based on the known opinion words (OO-Rel). [START_REF] De Marneffe | Generating typed dependency parses from phrase structure parses[END_REF]. Extracting products' features by using both the extracted opinion words and the related features; [START_REF] Dey | Text-Driven Multi-structured Data Analytics for Enterprise Intelligence[END_REF]. Extracting opinions based on the extracted opinions and features. The added two more tasks focus on implicit dependency relations especially for long distance dependency. Six catalogues of running rules are clarified for the proposed six tasks and the detail analysis is depicted in Table 2.

In Table 2, o (or f) represents for the obtained opinions (or product features). {O} (or {F}) is the set of known opinions (or features) either given or obtained. POS (O/F) means the POS information that contains linguistic category of words such as noun and verb.{NN, NNS, JJ, RB,VB} are POS tags to describe opinions or features. O-Dep represents the opinion word O depends on the second word based on O-dep relation, F-dep means the feature word F depends on the second word through F-dep relation. MR={nsubj, mod, prep, obj, conj,dep}, 'mod' contains {amod, advmod}, 'obj' contains {pobj, dobj}, which are dependency relations describing relations among words. Finally, the rules are formalized (we only show the main rules in this paper) and employed to extract features (f) or opinion words (O) based on the previously defined six tasks. (good→amod→photos) (Figure 2)

The images are excellent. (photos→conj→videos

) R4 O { } ( ) { } i ( j ) O Dep i ( j) j(i ) j(i ) i ( j) i ( j) O O , s.t. O O , advmod, O Dep , conj POS O RB - ∈ - ∈ ∈  →      
o=O{OO} Canon PowerShot SX510 takes significantly better indoor photos.

(better←advmod←significantly)

This camera is light and easy to hold.

(light←conj←easy)

Opinion Mining Extraction Algorithm

Table 3 shows the detailed opinion mining extraction algorithm. The initial values of the proposed algorithm are shown as: opinions dictionary O, the opinion degree intensifiers OD, and the review data RD. The opinion dictionary is based on Hu and Liu ( 2004) and the opinion degree intensifiers are defined by the authors. This algorithm adopts a single review from customers as the basic analysis unit. The products' features should be unique, while the opinion words to describe the features can be reused in each review. The algorithm stops when no more new features can be found. Input: Opinion word dictionary O, Opinion Degree Intensifiers OD, Review Data: RD Output: The set of features F, the set of expanded opinion words EO, the opinion polarity (or orientation) for a product: OW BEGIN 1. Expanded opinion words: EO= ∅ ; F= ∅ ; ODI= ∅ ; 2. For each dependency parsed review RDk 3. // Obtaining the initial opinion words and intensifier degree words in RDk based on the dictionaries of O and OD 4.

for each word tagged JJ,RB, and VB in RDk 5.

Traversing the RDk, and extracting the opinion words (OPi) if they are appearing in O; i++; 6.

Extracting new opinion words {OPj} in RDk by using the Rules R41-R42 based on extracted opinion words {OPi}; j++; 7.

Inputting the obtained OPi and OPj into EO, and then EO={OP[1,…,i] , OP[1,…,j] }(for short EO={ OP1-i, OP1-j }); 8.

Traversing the RDk, and extracting the degree intensifier words (DWd) if they are appearing in OD; 9.

Inputting the obtained DWd into ODI, and then ODI={DW1-d}; d++; 10.

End for 11. //Extracting the features based on the obtained initial opinion words and opinion degree intensifier words 12. Extracting features {Ffi} in RDk by using the Rules R1-R1 based on opinion words EO={OP1-i, OP1-j }; fi++; 13.

if (Extracted new features not in F) 14.

Extracting new features {Ffj} using Rules R31-R33 based on the new extracted features {Ffi}; fj++; 15.

Extracting and updating new opinion words {OP1-p} using Rules R21-R23 based on extracted features F={Ffi, Ffj }; 16.

Extracting new features {Ffp} in RDk by using the Rules R1 based on new opinion words EO={OP1-p}; fp++; 17.

End if 18.

Setting F={Ffi, Ffj , Ffp }; EO={OP1-i, OP1-j, OP1-p }; 19.

KernelFeature_OpinionSets=Build_kernel(F, EO, RDk); 20.

Recording In order to test the proposed algorithm, the raw customer opinion data were collected by using publicly available information from the Amazon site. The experiments were conducted in three domains that including Canon camera, Casio watch, and Nike shoes. The test data included 3,458 customer reviews of 17 different type canon cameras, 354 customer reviews of Casio G-Shock watch, and 252 customer reviews of Nike woman shoes. Feature-by-feature comparison of the studied products is conducted based on the extracted features, opinions, and feature-opinion relations. Moreover, the strengths and the weaknesses of the studied products are given, which has a beneficial effect on the new product development and customer personalized recommendation.

The Extracted Results Comparison for the Proposed Two Approaches

In order to demonstrate the differences between the proposed two approaches, we analyzed 517 reviews about the product of Canon PowerShot SX280. The focused keywords are 'zoom', 'video', and 'battery'. The TF-IDF approach can obtain the weight of each word in each document. The weights of studied keywords in seven documents are shown in Table 4. The results reveal the facts that the first document has the highest probability relevant with 'zoom' and the seventh document has the highest probability relevant with 'video'. The keyword 'battery' appears in most of the documents, which means the majority of customers have discussed the attributes related to 'battery'. The proposed opinion mining algorithm is adopted to extract information from the reviews related to 'zoom', 'video', and 'battery'. The important obtained information is analyzed in the following. More than half of the obtained feature-opinion in the battery dimension referred to a terrible battery quality, such as: 'bad battery life', 'battery died', 'battery drains', 'disappointed battery', and 'battery indicator issue' (Top 5 extracted negative frequent terms). Negative frequency terms of extracted feature opinion from the proposed algorithm are 'video problem', 'video issues', 'video shuts off', 'video not work', and 'disappointed video performance'. Moreover, 39.84% of extracted terms point to 'short battery life' and 21.48% are obtained as 'battery indicators issues'. Battery indicator issues are mainly about the indicators misleading the actual state of charge of the battery. The results also have 57 terms like 'defective firmware upgrade' in battery dimension. Therefore, we report the poor battery dimension, because of the battery life and the indicator problem; and the proposed solution from the company cannot completely solve the problem. As for the video dimension, the extracted results are more inconsistent and disorganized, such as: 'video camera died', 'minutes video battery shut(s) off', and 'zoom video mode battery shut down'. We can deduce that the video problem is probably caused by a battery problem.

Based on above analysis, the TF-IDF approach can be adopted to obtain the weights of studied keywords in reviews. The proposed opinion mining algorithm complements TF-IDF approach, which can extract more efficient information based on the content of reviews.

Conclusion

Information extraction is a tough problem that the existing approaches cannot obtain the desired extraction results. This paper globally views the existing approaches and then categorizes them into several groups based on the superiority and intelligence of the approaches and their capability to solve the complex information extraction (retrieval) problems. Two practical approaches are provided to demonstrate how to use the IE solutions based on different objectives. The first application aims to provide the front-end services for EASY-IMP project based on TF-IDF approach. The TF-IDF approach is adopted to analyze the customer's preference and determine the optimum interest of customers. TF-IDF approach is used to discover the most relevant keywords for the defined topics. Finally, roughly 100,000 pages have been analyzed and the customer's preference is determined based on the sets of selected keywords. In order to be more efficient for extracting the useful information from customer reviews, the opinion mining extraction algorithm is proposed. This algorithm can jointly identify features, opinion expressions, and feature-opinion, which capable to determine opinion boundaries and adopt syntactic parsing to learn and infer propagation rules between opinions and features. The proposed algorithm allows opinion extraction to be executed at the phrase level and can automatically detect the features that contain more than one word by building kernels through closest words. Experimental evaluations are conducted in 3,458 reviews and show that the proposed algorithm can complete the expected IE tasks. In the future, we will concentrate on testing the proposed algorithm. In order to obtain more accurate and efficient results, the proposed algorithm is considered as a supplement of TF-IDF approach when extracting information from various reviews.

Fig. 1 .

 1 Fig. 1. The Modules of Front-End Services

  , photos as the known word and good as the extracted word. photos and great videos too.

Fig. . . . 2 .

 2 Fig. . . .2. The dependency structure for the sentence: Canon PowerShot SX510 takes good photos

Table 1 . Example data: Term, Term Frequency and documents

 1

		Document 1		Document 2
	Term	Term frequency	Term	Term frequency
	Cricket	2	Cricket	1
	Rugby	1	Grappling	3

  The main modern information extraction solutions are categoried in the following: -Statistical approaches[START_REF] Dey | Text-Driven Multi-structured Data Analytics for Enterprise Intelligence[END_REF][START_REF] Blei | Latent dirichlet allocation[END_REF][START_REF] Blunsom | Hidden markov models[END_REF]: supervised or unsupervised to learn the properties or attributes of text; classification of content into various categories through analysis of humantagged labeled samples; extraction of hidden topics or grouping similar content. One of the representative methods is hidden Markov model (McCallum et al., 2000). This method calculates the probability that from one state to another based on the theory of probabilities, and hence obtaining the probabilities of several words emerging together. -Natural language processing approaches, which mainly contain three main components are shown in the following: 1). Taggers: POS (part-ofspeech)(Tsuruoka et al., 2005), which is used to understand the structure of the sentences. 2). Parses (McDonald et al., 2005; Nivre, 2005;De Marneffe et al., the components of a single sentence. To identify finer grained emotions like wish, anger, fear etc. 3). Named Entity Recognizer (Nadeau and Sekine, 2007), which is a special category of NLP tools that employ pattern recognition techniques to extract named entities from documents. Named Entities include names of people, places, organizations, product models, time (money) -values, email addresses; telephone numbers, etc.

	2006): Analyze	whole	sentence structures	and	try	to	derive
	semantic relationships among

graph(or Tree)-based method

[START_REF] Litvak | Graph-based keyword extraction for single-document summarization[END_REF]

: The type approach mainly has three parts that include sentence structure analysis, constructing graph database, and graph similarity for merging.

regular expressions

[START_REF] Li | Regular expression learning for information extraction[END_REF]

: Compile the regular expressions to explain the sentence pattern. machine learning (Aggarwal and Zhai, 2012): Define the specific rule or parameter to automatically extract the information.

Table 2 .

 2 Simplified Rules for Features and Opinion Expressions Extraction

	Rule	Input	Representation Formula	Output	Example
	R1	O	O	Depend (O-Dep) →	F;	f=F; {FO} Canon PowerShot SX510 takes good
			{ } where, O O , O-Dep ∈	photos.
			∈	{ } MR , POS F ( )	∈
			{	} NN, NNS

Table 3 .

 3 Algorithm: opinion mining extraction algorithm

	Algorithm Opinion_Mining_Extraction()

Table 4 .

 4 Sample Output of the TF-IDF Approach

	Document No.	1	2	3	4	5	6	7
	Weight('zoom')	0.1100	0	0.0204 0.0766 0	0.0464 0
	Weight('video')	0.0271	0	0.0151 0.0189 0	0.0229 0.0216
	Weight('battery') 0	0.0842 0.0197 0.0443 0.1010 0.0089 0.0112

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