Naimi Meriem

Ait-Aoudia

Ewa Berezowska-Azzag

Algiers water issue: Key indicators for a diagnosis of water resources carrying capacity

Keywords: Algiers water supply, Key indicators, Water system diagnosis, Carrying Capacity

In Algeria and especially in Algiers the capital city, ensuring inhabitants water requirements remains a critical issue despite huge investments made by the government to secure water supply over the past years. Indeed, in the face of erratic climate conditions with recurrent drought episodes and constantly increasing water demand, due to population growth and economic activity rise, the water supply system is subject to various problems of environmental, economic, technical and managerial nature. This could ultimately affect the water supply of Algiers city. A rigorous and effective management of water resources requires analysis of elements that affect in the long run water resources carrying capacity (WRCC). This latter can be defined as the level of human activity that can be withstood by the available water resources without major degradation of aquatic environments while maintaining an adequate standard of living for the population. Water resources carrying capacity depends mainly onto two major components that are water supply capacity and inhabitants' global water demand. This study aims at proposing key indicators and related thresholds for analysing Algiers water carrying capacity in order to provide a diagnosis tool for policy makers to lay down the foundations of a sustainable water strategy in Algiers city.

Introduction

Access to drinking water is a major concern as the survival of the human being depends entirely on it. Thus, the issue of securing water supply and sustainable management of this resource must be included in the priorities of any development strategy. This is all the more important in a country like Algeria, which have an average water availability less than 500 m3 per inhabitant per year well below the scarcity threshold set at 1000 m3 per inhabitant per year [START_REF] Falkenmark | The massive water scarcity now threatening Africa: why isn't it being addressed?[END_REF], is clearly in water stress situation. Even worse, the situation will get more dramatic due to global warming, which could lead to an increased recurrence of drought episodes.

Among Algeria cities, Algiers, the political and economic capital, suffered from severe water scarcity due to several factors. The most important ones are recurrent droughts conditions and high pressure on resources, due to a fast population growth. In order to meet the growing demand for water, the Algerian authorities have favoured a policy of supply, investing heavily in new infrastructures. Transfer systems were implemented bringing water from dams located hundreds of kilometres from the capital. At the same time, desalination of seawater has been implemented to address the problem of the shortfall in natural water supply, in this region subjected to recurrent episodes of drought. It should be noted that this process is quite costly in terms of energy, and the long-term impact on aquatic ecosystems is unclear.

As a result of the efforts made, Algiers' citizens benefit now from water availability 24 hours a day. However, this relative comfort in terms of water supply remains questionable in many respects, because: groundwater, due to exploitation beyond its potential, is threatened with exhaustion and subject, as they are coastal, to the phenomenon of marine intrusion; about half the volume of water allocated to the capital comes from superficial resources located in neighboring departments, which are forced to concede part of their water resources to the detriment of their own development (Chikhr Saïdi, 1997); Recurrent droughts greatly affect the contribution of these surface resources, while desalination of seawater cannot be a safe and sustainable solution as regards economical and environmental aspects [START_REF] Cotruvo | Desalination technology: health and environmental impacts[END_REF].

In view of these concerns, the objective of water policy is, on the one hand, to guarantee the sustainability of the resource and, on the other hand, to satisfy the demands of growing populations and different socio-economic activities, and allocating water amounts among different competitive uses taking into account local constraints [START_REF] Kettab | Les ressources en eau en Algérie: stratégies, enjeux et vision[END_REF].

A rigorous and effective management of water resources requires analysis of elements that affect in the long run water resources carrying capacity (WRCC) [START_REF] Shi | Carrying Capacity ofWater Resources in Urumqi River Basin and its Rational Utilization[END_REF][START_REF] Zhongmin | Scenario-Based Framework for Multicriteria Decision Analysis in Water Carrying Capacity[END_REF][START_REF] Li | Water resources supporting capacity of Chaidamu Basin[END_REF][START_REF] Liu | Water resources carrying capacity based on the theory of ANN[END_REF][START_REF] Feng | Application of system dynamics in analyzing the carrying capacity of water resources in Yiwu City, China[END_REF][START_REF] Li | Optimising the allocation of groundwater carrying capacity in a data-scarce region[END_REF]. This latter can be defined as the level of human activity that can be withstood by the available water resources without major degradation of aquatic environments while maintaining an adequate standard of living for the population [START_REF] Ait-Aoudia | Water Resources Carrying Capacity Assessment: the case of Algeria's Capital City[END_REF].

This study aims at proposing key indicators and related thresholds for analyzing Algiers water carrying capacity in order to provide a diagnosis tool for policy makers to lay down the foundations of a sustainable water strategy in Algiers city. This paper is organized as follows. Section 2 is devoted to Water carrying capacity key indicators. Thresholds of these indicators are detailed in section 3. The diagnosis of Algiers household water resources carrying capacity is given in section 4. Section5 concludes the paper.

Water carrying capacity key indicators

The study of the urban carrying capacity relative to water resources is based on two key concepts: supply capacity and the demand side. These two concepts will be fleshed out in a set of indicators.

Supply water indicators

To study the carrying capacity at the urban level, [START_REF] Oh | Determining development density using the Urban Carrying Capacity Assessment System[END_REF] define four components that are: environmental capacity, infrastructure capacity, perceptual capacity and institutional capacity. These components focus on the description of supply capacity. In the area of water, the environmental component represents amounts of water provided by the annual average flow of rivers and the annual renewal of groundwater resources; The infrastructure component represents the infrastructure for water intake and transport, as well as facilities for the production of unconventional resources, namely desalination of seawater and waste water recycling; Integrated water resource management has several objectives as increasing water availability by preventing resources from depletion and by promoting reuse, limiting water withdrawals to sustainable levels by maximizing water use efficiency, minimizing wastewater production and optimizing the distribution of water between competing users (OCDE, 1998); Perceptual carrying capacity includes human attitudes and behaviors.

In this study we will focus on indicators related to the environmental, infrastructure and management components. The objectives of these indicators are diverse and varied. Indicators for the environmental component aim at describing the factors affecting the overall availability of water resources. Infrastructure component indicators aim at assessing the actual capacity and effectiveness of infrastructure. The indicators of the management component are intended to characterize the effectiveness of regulation, institutions, and water services.

Finally, 10 indicators were chosen to describe the supply capacity: 'exploitation rate of groundwater resources',' surface water mobilization rate ',' desalination capacity ',' loss rate in adduction network ',' loss rate in the distribution network ',' Water reuse rate 'and' water structure ', Quality of administration and water service (ordinal scale), Quality of regulation (ordinal scale), Law authority (ordinal scale)

Individual water consumption indicators

The domestic consumption component focuses on measures to reduce domestic demand for drinking water in order to reduce water withdrawals. The three axes that are favored to get people saving water, and which we propose to describe through indicators, are pricing, promotion of water-saving household equipment and rainwater harvesting.

Key indicators for individual water consumption are, 'water expenditure in household budget', 'percentage of households with water-saving devices' and 'percentage of homes using rainwater'.

Indicators thresholds

Measurement scale

The relevance of an indicator depends on its ability to depict the phenomenon being measured. In order for an indicator to be appreciable, it is important to compare it to a benchmark value on an ordinal scale (which makes possible to establish a hierarchy with respect to the measured indicator, e.g. good, fair, poor) or on a cardinal scale that allows quantification of the measurement with respect to a target value [START_REF] Mayster | Une démarche pour négocier les décisions relatives à l'aménagement des territoires et à la gestion de l'environnement[END_REF][START_REF] Spangenberg | Towards indicators for institutional sustainability: lessons from an analysis of Agenda 21[END_REF] [START_REF] Desthieux | Approche systémique et participative du diagnostic urbain. Processus de représentation cognitive du système urbain en vue de l'élaboration d'indicateurs géographiques[END_REF]. This latter can be a standard proposed by international, national or even local bodies, resulting from a benchmark, or relating to the evaluation of the state of the phenomenon at different times [START_REF] Stokar | Planification directrice cantonale et développement durable[END_REF].

The three institutional indicators: Quality Index of Administration and Water Service, Quality of Regulation, Authority of Law, are qualitative indicators measured on an ordinal scale (good, fair, poor), All the other selected indicators are cardinal, so their assessment is quantifiable and is done in relation to a benchmark value. All these quantitative indicators are expressed as a percentage and could take values between 0% and 100% called extreme thresholds, which after standardization take respectively the values 0 and 100. The significant thresholds in the range 0-100 represent benchmarks defining intervals of values that the indicator: could or should take (recommended) represented by the green color, could take with reserve (reserve) represented by the orange color, avoid taking (prohibited) represented by red color, and finally could take but its impact would be insignificant compared to the system studied (not significant), represented by the gray color. We adopted this color code, inspired by nutrition labeling in use in some countries for its obvious and easy apprehension by decision-makers.

Indicators significant thresholds

Significant thresholds for indicators as regards exploitation of superficial natural resources refer to United Nations standards (in the comprehensive inventory of world resources (E/CN.17/1997/9) which set a water withdrawal rate not exceeding 40% for a sustainable use of the resources respecting the minimum needs of the ecosystems. Beyond 70% the situation is called critical [START_REF] Pnue | Fiches méthodologiques des 34 indicateurs prioritaires pour le suivi de la Stratégie Méditerranéenne pour le Développement Durable[END_REF] and reveals an intense shortage of water.

With regard to underground resources, water withdrawals should be made only from renewable water volume estimated 300 million cubic meter in order to avoid ground water lowering. In a study referred to as PAC on the coastal area of Algiers, a rate of withdrawals on the renewable water above 80 % is allowed, without exceeding the maximum threshold of 100% [START_REF] Larid | Analyse de durabilité dans le cadre du PAC « Zone côtière algéroise" (Algérie)[END_REF]. For this indicator, the threshold of 100% means exploiting totally the renewed volume of water. Exceeding 100% means that the water table level will drop until a state of dangerous depletion.

Due to the absence of national standards about the loss rate in adduction network and the loss rate in the distribution network, we have referred to performances in developing and OECD countries. Hence, the maximum threshold of lost in the distribution network is fixed at 10%, a performance achieved in several countries of the OECD [START_REF] Oced | Gestion de l'eau. Performances et défis dans les pays de l'OCDE[END_REF]. With regard to losses in adduction network, whose pipes are easier to fix, freed from the constraints of urbanization, a maximum threshold of 5% is adopted.

As well, a rate of 1% for the indicator 'water expenditure in household budget, constitutes the minimum threshold observed in several countries and local communities. Proper water pricing is necessary to cover the actual costs of water service but also to encourage the consumer to adopt a more sparing use of this scarce resource. The OECD estimates that it is possible to go up to a rate of 3%, if necessary. It is also worth noting that a rate of 10% or more can be a threat to the standard of living of low-income households.

Indicators related to wastewater reuse, rainwater recovery and the use of water-saving appliances reflect the success of the policy of promoting the rational use of water resources. The goal is to reuse 100% of the wastewater and to get 100% of the households installing rainwater recovery and water-saving appliances. However, below the threshold of 5%, the impact on water demand will not be significant.

As regards desalination of seawater, setting thresholds is not evident, since it is an expensive process for the production of drinking water [START_REF] Thivet | La gestion de la demande en eau : L'expérience méditerranéenne[END_REF], and the knowledge surrounding this technique is still insufficient to assert that it is safe for the marine aquatic environment. In some countries the supply is only made through desalination but the use of this process is still subject to reservation. Therefore the whole field of value relating to this indicator will be set to reserve.

The same applies to the amount of water allocated to domestic households, which depends on socio-economic conditions, level of development, nature of the predominant activities in the region and also climatic hazard which, in some cases forces to privilege domestic consumption. The current amount of domestic use is about 51% but could be increased if measures are taken to promote more efficient use of water by other activities such as the generalization of economical irrigation techniques, wastewater reuse by industrial and agricultural activities.

Algiers household water resources carrying capacity diagnosis

For an easy reading of the indicators values, we use a stacked bar chart. Every stacked bar, corresponding to one indicator, has colors according to defined significant thresholds. The diagram become, hence, a matrix for reading indicators values. Figure 1 shows color code for the indicators and the measured value of each indicator relative to the situation of Algiers. The measurement of key indicators provides a global view of the main determinants of the carrying capacity of water resources in the capital city.

In terms of supply capacity

From a previous study, we know that the infrastructure in place allows us to mobilize about 20% of the water collected in the watersheds, that groundwater table is overexploited and that the desalination water constitutes 17% of the total amount of water allocated to the capital (Naimi-Ait-Aoudia & Berezowska-Azzag, 2014). In addition, the loss rates are around 12% in the supply networks [START_REF] Benblidia | L'efficience d'utilisation de l'eau et approche économique[END_REF], and 30% in distribution networks according to SEEAL the company in charge of water management in Algiers. Thus, apart from the exploitation of surface resources, which has a positive value and reflects the region's perspective in improving water supply capacity through the construction of new dams, the rest of the indicators of this category are in orange and red, which implies the need to take tangible measures to improve the availability of water and preserve the underground resources.

In terms of management capacity

The Algerian government seems to have succeeded in setting out a water management policy. The legislation adopted is clear [START_REF] Benblidia | Gestion des ressources en eau : les limites politique de l'offre[END_REF], covering all aspects related to the water sector, namely exploitation and concession of resources, pricing, combating water pollution and social policy. In addition, under a recent law, the concept of sustainability has become a guideline for water policy. The shift from sector management policy to sustainable and integrated resource management was achieved through the establishment of river basin agencies [START_REF] Benblidia | Gestion des ressources en eau : les limites politique de l'offre[END_REF][START_REF] Mozas | État des lieux du secteur de l'eau en Algérie[END_REF] which take, among other things, responsibility to raise domestic, industrial and agricultural users awareness for rational use and protection of resources. It should be noted that the status of basin agencies provides for the participation of users in the preparation of master plans (BAfD/OCDE, 2007), a first in the annals of management in Algeria. However, river basin agencies face difficulties in becoming a mediator in integrated water resources management, due to duplication of work with central government departments and lack of financial resources. Despites this, the quality of the administration appears to be generally satisfactory. [START_REF] Mozas | État des lieux du secteur de l'eau en Algérie[END_REF] underline a better distribution of competences between the different agencies in the water sector compared to the past. Ultimately, it seems clear that the public authorities have the necessary institutional means to lead the management of a sensitive sector in the country, even if there some flouting in law enforcement.

In terms of demand regulation

While the Algerian government has made considerable efforts to increase supply capacity, efforts to make efficient use of this resource have been delayed or not undertaken at all. From all the actions aiming at reducing water demand described by the key indicators selected, only that relating to pricing was implemented. Prices have been revised upwards in conjunction with gradual pricing in terms of volume consumption.

The incentive for water savings should be implemented through awareness of consumer about the importance of preserving this valuable resource and the advantages of adopting behaviors aimed at that goal both on environmental and economic aspects. Furthermore, the gain that might bring the reuse of water was unfortunately ignored for a long time by public authorities. But recently, the intention to exploit this water potential, especially in irrigation, was clearly stated in the preparation of the Metropolitan Land Use Plan.

Conclusion

The urban management aims at matching the objectives of urban development with urban ecosystem capacity to provide the necessary resources for human development. That is why the management of water demand as much as on supply is of critical importance especially in a country with limited fresh water resources like Algeria. In this respect, water carrying capacity assessment provides, policy makers, elements of appreciation to lay down the foundations of a sustainable urban development policy. Based on the characterisation of both supply and demand water components, we have proposed key indicators and related thresholds for analysing Algiers water carrying capacity in order to provide a diagnosis tool and a dialogue interface for policy makers to negotiate possibilities for improving the water service while maintaining water resource sustainability.

Figure 1 .

 1 Figure 1. Vectorial stacked bar chart for the diagnosis of water policy.

Table 1 .

 1 Indicators and related thresholds.

	Indicator	Significant thresholds
	exploitation rate of renewable groundwater resource	≤80% Recommended	> 80% et <100% with reserve	>100% To avoid
	Surface water mobilization	≤ 40%	> 40% et <70%	>70%
	rate	Recommended	with reserve	To avoid
	Desalination capacity		with reserve
	loss rate in adduction	≤ 5%	> 5%
	network (%)	with reserve	To avoid
	loss rate in the distribution	≤ 10%	> 10%
	network	with reserve	To avoid
	Water reuse rate	≤ 5% Not significant	> 5% Recommended
	Domestic water structure	<50% with reserve	≥50% Recommended
	Quality of administration	Poor	Fair	Good
	and water service
	Quality of regulation	Poor	Fair	Good
	Law authority	Poor	Fair	Good
	water expenditure in	≥ 1% et ≤3%	<1%, >3% et ≤10%	>10%
	household budget	Recommended	with reserve	to avoid
	percentage of households	< 5%	≥ 5%
	with water-saving devices	Not significant	Recommended
	percentage of homes using	< 5%	≥ 5%
	rainwater	Not significant	Recommended


Arnim Nethe
email: arnim.nethe@tu-cottbus.de

Irene Krebs

A New Electronic Path to the Hospital -a Prenatal Observation System

Keywords: telemonitoring, IT-system, secure access, virtual visitor system, health care, early born children

Premature babies represent a particularly endangered group of children. At the same time, their parents are frequently traumatized by the early birth and full of fear for their child. The question which arises here now is how parents can build up a relationship to their child. This article describes a visitor system which establishes the connection between child and parents and, on the other hand, could substantially support the hospital personnel with their daily work. A clinical example for this e-health application is given. This is a faster step in the direction of e-society.

Introduction

Telemedical applications, such as intelligent assistance systems and telemonitoring systems, and their technical implementation gain more and more importance. According to BBC Research, the global market for telemedical systems alone will annually grow to approx. 11 billion Euros till 2012 [START_REF] Reinhardt | Potenziale für intelligente Assistenzsysteme[END_REF]. Based on current research an application for a new target group in telemedicine is presented in this paper. For this practice-oriented example only few field tests have been conducted worldwide [START_REF] Leduc | An observation unit in a pediatric emergency department: One children's hospital's experience[END_REF][START_REF]Vocera Benefits Study at The Children's Hospital at Westmead, Prepared by The NTF Group March 2007[END_REF].

Premature Infants and Ill Newborn Children

Premature infants represent a particularly endangered group of children. At the same time their parents are frequently traumatized by the early birth and full of fear for their child. In this situation we must not leave them alone, but must help them to be able to be there for their children because especially in the first weeks of life they particularly need the attention of their parents.

About 60,000 premature babies are born in Germany per year -with rising tendency: Despite a sinking birth rate premature babies constitute an ever larger share of all newborn children. Meanwhile 8.5% of all newborn children are premature babies. Thus they form the largest children's group of patients in the Federal Republic. Of the 60,000 premature children per year about 8,000 children are born with a birth weight of less than 1,500g. Despite the early birth a large part of these children is in a good course of development. About 30% are risk patients with different forms of restriction and handicap.

In addition to this, investigations verify that the social environment is of particular importance for the optimal support of premature and ill newborn children. After early birth, parents experience a phase of severe stress, accompanied by fears, feelings of guilt and helplessness. Frequently the situation asks too much of them. It is difficult for them to establish a relationship to their child in the hospital. Incubators, medical equipment, cannulae and tubes are additional barriers.

Particularly very premature children spend a long time in the incubator in a nonnatural environment in the neonatological intensive care unit. Studies indicate that the attachment behavior of premature infants frequently exhibits uncertainties or is even disorganized, as it is often observed with abused children. Therefore a failed establishment of relationships can result in permanent impairments of the cognitive, social and emotional development of the child. The fear for the survival of the child, the concern about the health development and possible impairments as well as the own feelings of guilt of having "caused" the situation impair the basis for a stable parenthood [START_REF] Kinderhilfe | Das Frühförderprogramm der Deutschen Kinderhilfe (FFP)[END_REF].

A Concept for the Improvement of the Situation

The question which arises here now is how a mutual bond can be established and developed. In addition, the psycho-social support of the families is a significant factor which must be considered.

A possible solution can be a virtual visitor system in the neonatology intensive care unit. If parents could see the baby again the evening before bedtime, that would minimize the fears and increase the bond to the child. Thus family life can also be more relaxed since the new family member can be integrated into the family. The parents can show the child to friends and relatives and thereby integrate him/her into the family environment. In addition, the virtual visitor system would supplement the control services of the hospital personnel. It is possible for the personnel to additionally observe the child by a camera from the monitoring room. In cases when the child accidentally pulls out the tubes, the nursing personnel can react faster because this can be noticed by the live monitoring.

Thus, on the one hand, the virtual visitor system would strengthen the mutual bond between child and parents and, on the other hand, would substantially support the hospital personnel in their daily work. Thus the nurses, hospital aides and physicians can do their jobs more productively and more efficiently.

The approach of installing a prenatal monitoring system -we call it "BabyLive"in hospitals cannot be taken for granted today, although the advantages are obvious and a technical implementation would be possible without any problems. In the following part it is explained how the approach described can be implemented and which factors have to be considered.

IT Concept for the Implementation of the BabyLive System

In an IT concept all technical prerequisites for the implementation of the project in a hospital are described. A basic prerequisite for the IT application is, among other things, the development and implementation of a uniform IT security concept with the goal of guaranteeing the integrity, confidentiality and availability of data and services, the operation of an efficient, highly-available, preferably open and safe clinical center net for the transmission of digital data of all kinds as well as the build-up and operation of a need-oriented support structure.

In addition to the basic equipment of the workplaces, the users expect that a number of superordinate IT services are provided with high availability and reliability. This includes, among other things, a central listing service for purposes of user, assigning the parts, the rights management, a network server for the supply of the personal computers, secured access to the clinical center net, IT security checks, as well as reactive and proactive IT safety precautions (e.g. firewall, intrusion detection, intrusion prevention, virus defense, spam defense), email services as well as videoconference services (video transmission of the child's photographs).

Services in the IT Environment

In connection with the basic equipment and IT services mentioned above there are also further requirements. They can roughly be divided into four groups:  A platform for rapid informing about current events on the homepage of the clinical center and information about the further development of BabyLive by means of newsletter.  A consultation for informing parents about the use of the service and a catalog for frequently asked questions (FAQ).  Training on general IT topics for nursing personnel and parents for using the service BabyLive.  Technical support for the staff, analysis of the use of the service, assessment and/or planning of IT procurements as well as the procurement of software on the basis of valid contracts.

Security in the IT Environment

The planning phase covers the threat analysis, a risk analysis, the preparation of a safety strategy and a safety model. In the threat analysis possible dangers are determined and their causes such as organizational, technical or user-related causes are found out. These tasks can only be mastered if certain knowledge and experience in the field of IT security is available and the weaknesses of the existing systems and services are known (see Fig. 1).

Fig. 1. Process model for the implementation of the BabyLive system [START_REF] Poguntke | Basiswissen IT-Sicherheit. Das wichtigste für den Schutz von Systemen & Daten[END_REF] In the risk analysis the determined threats are evaluated. The evaluation contains, on the one hand, the estimation of the probability of the occurrence of the threats, and, on the other hand, the estimation of the caused potential damage when a threat occurs. Due to the threat and risk analysis it can be decided which safety requirements are to be set for the system to be designed. These requirements are summarized in a safety strategy. To meet the security needs general basic safety functions can be used. These functions are:  Identification and authentification: Subjects and objects must be clearly identifiably, for example with the access to resources or to certain files. To facilitate identification characteristics for an authentification must be specified, such as passwords and a digital fingerprint.  Rights administration: This concerns the prevention of unauthorized access to objects. Administrative rights must be specified for the objects to be protected, such as reading and writing rights.  Rights examination: In order to implement rights administration the accesses must be controlled. This is the task of rights examination. For this the time and the kind of control must be specified. Further the measures to be taken in cases of unauthorized access must be regulated.  Preservation of evidence: The preservation of evidence is to secure proof so that accomplished actions cannot to be denied later. For this it must be specified which events and information are to be logged and who possesses access to the logged information.  Reprocessing: To retain information privacy shared operational funds must be settled before another process accesses them.

Practical Example in the Pediatric Clinic of the Carl-Thiem-Klinikums (CTK) Cottbus

The neonatology unit of the pediatric clinic of the Carl-Thiem-Klinikum Cottbus is one of four institutions of care level 1 in the Federal State of Brandenburg. Care level 1 means that only these institutions are allowed to bill health insurance companies for the treatment of newborn children under a birth weight of 1250 grams. Further hospitals with neonatology units are located at a great geographical distance from Cottbus.

The neonatology unit in Cottbus is divided into two sections. In the intensive room for premature infants in the delivery room ill premature and newborn infants are primarily treated, for example those who need breathing support. The second section is the intensive care unit for premature infants, where those newborn children are cared for who do not need intensive medical treatment (any more). [START_REF] Erler | Die Gesichter der Opfer -Auswirkungen von Gewalt bei Kindern und Jugendlichen erkennen[END_REF] In all areas of the neonatology unit where premature infants are cared for, connections for hospital-internal communication are available. Furthermore, the monitors (security camera screens), which for example display the heart frequencies of the children, are all interconnected with one another. These data can be retrieved by means of administrative software at several terminals at the unit. The clinical center has its own homepage with a babysite, where only photos of newborn children have been made available so far. This site could be supplemented by an extension for retrieving video transmissions of the children. Due to the special operation of a hospital information system it is necessary to parallel implement the complete infrastructure for the BabyLive system. After the introduction to IT security it is now to be illustrated how internal and external security can be implemented using the pediatric clinic in the CTK as an example. For the illustration of the section which is to be considered here see figure 2.

The internal view represents the Carl-Thiem-Klinikum Cottbus and the participants who use video transmission and can be observed by the camera. The pictures are transferred to the Internet platform. The users of the platform, such as the parents, can then access the Internet platform and the picture transmissions. The Internet platform is an interface between the clinical center and the platform users. Additionally to the users already specified, the nursing personnel can also use the service. The nursing personnel can track the picture transmission of all cameras on the computer in the monitoring room.

Internal Security

For internal security no information should get out which is not intended for the outside world. This could be, for example, the treatment of the child which is not to be filmed and thus must not become visible by the users of the platform of the virtual visitor system, but also the protection against an internal access to the system by unauthorized people. First, possible risks for the clinical center and its personnel must be listed. These are:  The treatment and care of the child by the nursing personnel and the physicians are filmed and transmitted.  Staff of the clinical center could overhear the data traffic.  A coworker can use the service of the video transmission for which s/he does not possess authorization.  By pretending identity a coworker reroutes the data.

From the threat analysis the following protection goals result:  Video transmission must be prevented during the treatment and nursing of the child.  The access to the service, the servers and the data must be controlled and checked. Before using the service the personnel must authorize themselves. So that the nursing personnel and the physicians are not observed during the treatment of the child, the camera must either be turned off every time or the bed is put away from the camera. However, this is too difficult, costs time and especially in emergencies cannot always be implemented. Instead a sign could be attached in front of the lens of the camera, for example with the text "I am off" or "I am being fed", which is placed in front of it every time the child is not to be observed. The solution is simple, does not cost too much time and the user of the Internet platform knows what is happening in these moments.

So that the data traffic cannot be overheard by staff, it must be ensured that the net of the video transmission is operated separately from the remaining clinical center net.

Thus only the staff of the neonatology unit can access and use the service of the virtual visitor system. Further, authorization before using the service can guarantee that no unauthorized persons have access to the data communication on the net and thus cannot reroute or abuse the data.

External Security

The ways from the Internet platform to the user of the platform and from the user to the platform are of importance for external security. Possible dangers could be:  Unauthorized access to the Internet platform,  Abuse of the access to data,  Spoofing of emails by an aggressor,  Unauthorized reading of emails,  Attack on communication between the interface and the PC of the user,  Spoofing of the identity,  Execution of malware on the web server by the user.

From the threat analysis the following protection goals result:  Access to the service and the data must be controlled and checked.  Before using the service the user must authenticate himself/herself.  The integrity, authenticity and privacy of emails must be guaranteed.  Access of the user to the clinical center's internal net must be impossible. For the implementation of the schematic representation of the BabyLive system shown in Figure 3 the following steps are necessary: On the Internet site of the Carl-Thiem-Klinikum Cottbus a link is to be established, which is to refer to the site of the BabyLive system. The link indicates the IP address of the SDSL modem of the unit.

Technical Realization

For safety reasons, an inquiry about the user name and the password will be carried out here. This authentification is global, i.e. each user of the camera platform has this registration for the front page of the cameras. The protection is organized so that no unauthorized persons can access this homepage. Furthermore, this global registration is logged in a log file. This file can also be used for statistical purposes in order to determine how successfully this service is used and if further investments would be worthwhile. A camera is assigned to every child. The parents select the camera which was assigned to them. Again there will be an inquiry about the user name and the password. The router implements port forwarding to the server in the nurses' room, on which the hosting of the webpage of the camera entrances is run. The IP addresses of the cameras are mapped on the individual IP of the server by the port forwarding, so that the internal infrastructure remains transparent for the user. After the authentification the video transmission of the child becomes visible by means of a live stream point to point. This means that the video transmission is converted into a video/audio stream in real time by means of encoder software. In this way the stream can be transmitted via the Internet. Point to point streaming means that a central server provides a connection between the participants (child/parents). This data exchange is server independent. The video transmission is only stopped by logout or the end of the visiting time. The visiting time is dependent on the organization of the care of the children, as it is also usual with normal visits in the hospital. Furthermore, the visibility of the child in the net can be disturbed by certain events, for example when the child is being fed or examined. As already mentioned, in such events posters are placed in front of the camera.

The relatives take over a significant part of the implementation. They must make themselves familiar with the technology, receive instructions and give their agreement for the video transmission. In order to make the project a success, parents would have to accept and use this hospital service. The extent to which the service offered is used helps decide whether there should be more investment in this project.

The fear that the pictorial material could be abused by unauthorized people can be taken away by entrance identification. By this identification only authorized users of the respective camera can see the child. If the relatives forget the access code, the staff of the hospital can help by generating a new access code and a new password (see Fig. 4 and Fig. 5).

Conclusions

Today there is a highly complex IT structure in every hospital. The implementation and adaption of a completely new access path with previously non-existent users for a prenatal observation system increases the complexity of this IT structure. Thus, among other things, new requirements arise regarding the development and implementation of a uniform IT security concept with the aim of guaranteeing the integrity, confidentiality and availability of data and services, organizing the operation of a highly efficient and available, preferably open and secure hospital network for the transmission of digital data of all kinds as well as organizing the setup and operation of a demand-oriented support structure. In addition, there is the training of all people involved on how to use the prenatal observation system.

A priori a modern hospital is a part of e-health. Thus with this prenatal observation system a telemedical platform is created for the computer affine generation of young parents with which a children's hospital can significantly improve e-service and in this way can make a big step in the direction of e-society.

Fig. 2 .

 2 Fig. 2. Participants and use relationships

Fig. 3 .

 3 Fig. 3. Schematic representation of the BabyLive system

Fig. 4 .

 4 Fig.4. Homepage of the Internet platform: "Welcome to BabyLive: With the project BabyLive parents of premature infants at the unit K3 of the hospital for child and adolescent medicine of the CTK are offered the possibility to visit their child "virtually". This means that a web camera is installed at the bed of the child via which parents can see the child at all times of the day and night. Using the field "Kamerazugang" you can select the camera which was assigned to you. Then you only have to authentificate yourselves and see your child live".

Fig. 5 .

 5 Fig. 5. Camera site of the Internet platform


Hele-Mai Haav
email: helemai@cs.ioc.ee

A Practical Methodology for Development of a Network of e-Government Domain Ontologies

Keywords: ontology, ontology networks, ontology development methodology, e-government

Ontologies are widely proposed for solving semantic interoperability problems in e-government domain. However, less attention is paid on methodological issues of ontology development in this domain. These are not sufficiently solved. Existing approaches in ontology development are technically very demanding and require long learning curve and are therefore inefficient for this purpose. E-government domain ontologies could be efficiently developed by domain experts rather than ontology engineers. The paper proposes a novel ontology development methodology for construction of light-weight domain ontologies by bringing ontology modeling closer to domain experts that are actual domain knowledge holders. The approach is illustrated and evaluated by development of a network of e-government domain ontologies used for achieving semantic interoperability of state information systems (IS) in Estonia.

Introduction

Applicability of semantic technologies in the e-Government domain has been investigated for many years. A number of EU projects (e.g. SemanticGov [START_REF] Loutas | Providing public services to citizens at the national and pan-european level using semantic web technologies[END_REF], SmartGov [START_REF] Georgiadis | SmartGov: A Knowledge-based Platform for Transactional ElectronicServices[END_REF], OntoGov [START_REF] Stojanovic | Ontologyenabled e-Gov Service Configuration[END_REF], Access-eGOV [START_REF] Bednár | Semantic Integration of Government Services -the Access-eGov Approach[END_REF], etc) are devoted to the several aspects of using ontologies in e-government domain and for different applications. Most of the projects are dealing with building semantic e-government services (i.e. electronic governmental services enhanced by semantic annotations) in order to provide their semantic interoperability.

Many member states of the European Union have started some semantic interoperability initiatives as for example Italian's initiative in public administration 1 , Finnish semantic initiative FinnONTO [START_REF] Hyvönen | Building a National Semantic Web Ontology and Ontology Service Infrastructure -The FinnONTO Approach[END_REF], Semantic Latvia project [START_REF] Barzdins | Towards Semantic Latvia[END_REF] and Estonian Semantic Interoperability Framework [START_REF] Haav | Ensuring Large-Scale Semantic Interoperability: The Estonian Public Sector's Case Study[END_REF][START_REF] Tomingas | Semantic Interoperability Framework for Estonian Public Sector's E-Services Integration[END_REF].

There are also pan-European initiatives, which include SEMIC (SEMantic Interoperability Centre Europe) 2 and SemanticGov project [START_REF] Loutas | Providing public services to citizens at the national and pan-european level using semantic web technologies[END_REF].

However, practical effects of this research and initiatives to e-government domain and applications do not well meet expectations.

One of the main reasons as three years experience of Estonian semantic interoperability initiative shows is complexity of the semantic modeling (e.g. ontology development) and annotation process. There is lack of ontology development methodologies that are not technically demanding in order to be used by e-government domain experts and that are easy to learn by employees of public administrations (PA-s).

This paper concentrates to the problem of complexity of semantic modeling by answering the question: How to easily develop domain ontologies that could be used for semantic annotation of e-government data services?

Majority of current ontology development methodologies [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF][START_REF] Haase | NeOn Deliverable D1.1.1 Networked Ontology Model[END_REF][START_REF] Staab | Knowledge Processes and Ontologies[END_REF][START_REF] Uschold | Ontologies: principles, methods and applications[END_REF]] require a role of mediator (e.g. knowledge engineer) between actual knowledge holders (e.g. domain experts) and ontology engineers who encode knowledge in one of available onotology formalisms (e.g. OWL 3 ).

In contrast, this paper proposes a novel ontology development methodology for construction of light-weight domain ontologies by bringing ontology modeling closer to domain experts (PA employees) that are actual knowledge holders. The methodology could be used for construction of domain ontologies by domain experts without any high level knowledge of semantic technologies.

The approach is illustrated and evaluated by development of network of egovernment domain ontologies used for annotation of governmental data services in order to support semantic interoperability of state information systems (IS) in Estonia.

The paper is structured as follows. Section 2 gives a brief overview of related semantic e-government projects and ontology creation methodologies. In section 3 a motivating Estonian e-government case study is described and analysed. Section 4 presents a practical ontology development methodology for network of e-government domain ontologies. Section 5 is evaluation of the methodology and section 6 concludes the work.

Related Works

Majority of e-government projects use ontologies for achieving semantic interoperability and integration between e-Government systems. For example, in OntoGov [START_REF] Stojanovic | Ontologyenabled e-Gov Service Configuration[END_REF] ontologies are constructed for representing the meaning of processed data, resources and provided functionality of e-Government services. However, it is not always clear, what methodology is used for the ontology development in egovernment projects. Usually top-down approach is used. There are some general methodological approaches (e.g., METHONTOLOGY [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF], On-To-Knowledge [START_REF] Staab | Knowledge Processes and Ontologies[END_REF], etc.) for ontology construction. More detailed overview of wide range of methodologies can be found in [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF].

The most well-know methodology is METHONTOLOGY methodology [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF] that enables the construction of ontologies at the knowledge level. METHONTOLOGY is based on the main activities identified by the software development process [START_REF]IEEE Standard for Developing Software Life Cycle Processes[END_REF] and by knowledge engineering methodologies. This methodology includes the ontology development process, a life cycle based on evolving prototypes and techniques to carry out each activity in the management, development and support activities. Another approach is TOVE [START_REF] Uschold | Ontologies: principles, methods and applications[END_REF] where authors suggest using questionnaires, which is useful where domain experts have very little knowledge of knowledge modeling.

There are also attempts to improve existing methodologies by incorporating Rapid Application Development (RAD) approaches in ontology development [START_REF] Lavbiĉ | Rapid Ontology Development[END_REF][START_REF] Zhou | Toward Rapid Ontology Development for Underdeveloped Domains[END_REF].

The NeOn [START_REF] Haase | NeOn Deliverable D1.1.1 Networked Ontology Model[END_REF] ontology development methodology takes software engineering approach and goes step further having an ambitious goal to serve as a methodology for building a very large number of ontologies embedded in ontology networks built collaboratively by distributed teams. NeOn methodology is also supported by several tools collected into the NeOn toolkit [START_REF] Haase | NeOn Deliverable D1.1.1 Networked Ontology Model[END_REF].

All these approaches have turned ontology construction to an engineering activity. However, there is lack of methodologies that follow a user-oriented (e.g. domain expert oriented) approach. The majority of approaches require extensive technical knowledge of formal languages and techniques for capturing knowledge of a domain.

Therefore, this paper is devoted to bringing ontology modeling closer to domain experts. The proposed practical methodology for e-government ontology building is taking into account some of the proposals from the NeOn methodology as egovernment ontologies in principle are networked ontologies.

Use Case: Semantic Interoperability of e-Government Services in Estonia

In Estonia, interoperability of state IS-s is achieved by using middleware platform X-Road [START_REF] Kalja | New version of the x-road[END_REF] that provides the technical interoperability of the components and registries of state IS. X-Road is a technical and organizational environment that enables secure data transfer between digital government databases and enables secure data transfer between individuals and government institutions. X-road platform is based on SOAP4 standard and governmental e-service descriptions are presented in WSDL5 language. According to the statistics of the using X-Road [START_REF] Kalja | New version of the x-road[END_REF] the estimated number of uses in 2010 was 100 million.

The X-Road does not support semantic interoperability. In order to initiate semantic interoperability activities, Ministry of Economic Affairs issued strategic document on semantic interoperability of state information technology (IT) in 2005. This document presents a vision of semantic interoperability of state information systems in Estonia. Following this vision, the semantic interoperability architecture for Estonian state IS-s was proposed in 2007 [START_REF] Haav | Ensuring Large-Scale Semantic Interoperability: The Estonian Public Sector's Case Study[END_REF]. It is designed as the semantic layer to be built on top of X-Road infrastructure.

Important components of semantic interoperability architecture are domain ontologies of state IS-s. Primary use of ontologies as foreseen by the architecture is semantic annotation of descriptions of e-government data services and data structures of databases of state IS-s. As WSDL descriptions of existing services are available then SAWSDL 6 has been chosen for enabling these to be enhanced with semantic descriptions. For data structures, their XMI7 descriptions are enriched with SAWSDL references to corresponding components of domain ontologies.

As a repository of ontologies and semantic descriptions, the Administrative System of the State Information System (RIHA) [START_REF] Parmakson | The administration system of the state information system (RIHA)[END_REF] is used. It is a secure web-based database and software application that supports various processes of public sector information systems and that stores systematic and reliable metadata about public databases. According to statistics [START_REF] Parmakson | The administration system of the state information system (RIHA)[END_REF], at the end of 2009, RIHA contained the data of 450 databases and IS-s.

Another important tool currently under development is SEHKE [START_REF] Tomingas | Semantic Interoperability Framework for Estonian Public Sector's E-Services Integration[END_REF] that is a webbased collaborative environment for creating, managing and annotating semantic resources of state IS-s and registries.

The semantic interoperability architecture was set up and supported by related legislation in Estonia in 2008 demanding from holders of state IS-s creation of corresponding domain ontologies and semantic annotations of web-services. However, in reality this is not happening so easily. There is lack of knowledge about semantic technologies in general and about ontology engineering in particular. Within the semantic interoperability framework a large number of training courses have been provided to stakeholders (i.e. approximately to 200 participants), mainly to domain experts, who are responsible for ontology creation in their respective domains. A feedback from the very first training courses already has shown a need for a methodology and guidelines for ontology development that are closer to domain experts than general existing methodologies. In public administration agencies, it was impossible to have a large number of ontology engineers or knowledge engineers to help to convert domain knowledge to a formal ontology. The practical methodology for development of e-government domain ontologies presented in this paper is motivated by the situation described above.

A Practical Ontology Development Methodology

Goal, Object and Approach of the Methodology

A practical ontology development methodology presented in this paper aims at providing a systematic approach to development of ontologies capturing domain knowledge and semantics of databases fields related to different state IS-s. Most important goal of ontology development is their reuse across many applications and for building other ontologies.

From the methodological point of view, development of ontologies is a complex task and a lot of ontology building experiences are needed in order to produce well established ontologies. Therefore, one of the goals of current methodology is to make ontology development process easier for domain experts by providing processes and guidelines that they could use.

The provided methodology is primarily intended to be used for development of ontologies represented in OWL enabling semantic annotation of database objects and e-government services (described in WSDL) of state IS-s.

In reality, domain ontologies of state IS-s form a network of ontologies, in what different domain ontologies are related by linking, modularity, versioning or by other relationships. Such ontology network creates certain requirements to ontology development methodology. Ontology maintenance becomes much more complex in the case of ontology network than in the case of isolated ontologies.

Concerning methods for building domain ontologies, already accepted ontology development methodologies like METHONTOLOGY [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF] and NeOn [START_REF] Haase | NeOn Deliverable D1.1.1 Networked Ontology Model[END_REF] are taken as a basis for creation of a new methodology that better meets specific needs of domain experts.

Ontology Development Process

The ontology development process refers to activities that are performed when building ontologies as defined in METHONTOLOGY methodology for ontology construction [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF]. Ontology development process proposed in this paper is based on this definition. It takes into account as an input different re-useable knowledge resources that are available in governmental agencies, who are responsible of their IS as well as resources managed by developers of those IS. For example, re-useable knowledge resources could be regulations of creation of a state IS, conceptual schema of a state IS database, data structures in the form of XMI file, descriptions of data services etc.

For creation of a domain ontology for each of the state IS domains an iterative life cycle model was chosen. According to this model ontology development starts from partial satisfaction of requirements. During each of the iterations ontologies will be improved until all the requirements will be met. This life cycle model was successfully used in development of many domain ontologies of Estonian state IS including the most important and complex ones as ontology of central commercial register 8 , address objects, mineral deposits, Estonian topographic database etc. In development of a network of domain ontologies of state IS a method of evolutionary prototyping is proposed. According to this a partial result (a partial network of state IS domain ontologies) that meets known requirements is developed at first. This prototype of ontology network is evaluated and assessed by using it in different applications and the requirements are refined based on such evaluations.

(Re)usable Knowledge Resources

Reusable knowledge resources are formed from general and specific domain knowledge, non-ontological and ontological resources. Reuse of these resources speeds up ontology development process. Non-ontological resources are conceptual schemas of databases, glossaries, vocabularies, thesauri, regulatory documents of a state IS, descriptions of database objects, databases, service descriptions, etc. Ontological resources are existing ontologies in RDF or OWL format available at ontology libraries or repositories. For example, domain ontologies of state IS collected to RIHA repository could be reused for construction of a new ontology in ontology network.

Sequence of Activities

Sequence of ontology development activities is depicted in Figure 1.

Non-ontological resources Ontological resources

Ontology in OWL

Figure 1 shows also relationships of non-ontological and ontological resources with development process through corresponding activities.

Main activities of ontology development process are given in the Figure 1 as the following sequence: specification, conceptualization and implementation. According to iterative life cycle model early implementation of domain concepts and relationships is foreseen. At the first iteration, basic (central) domain concepts and relationships are arranged to ontological structure and implemented. After that, during each of the iterations, new concepts and relationships are added and implemented. Attributes of individuals of concepts are added in the final stage. After that ontology is evaluated according to the requirements e.g. are all input/output parameters of web services covered by corresponding components of respective domain ontology?. If not, then missing components need to be added.

In the following sections the ontology development process and corresponding activities are provided in detail.

Management and Support Activities

Management and support activities are similar to those defined in METHONTOLOGY methodology [START_REF] Gómez-Pérez | Ontological Engineering with examples from the areas of Knowledge Management, e-Commerce and the Semantic Web[END_REF]. Ontology development starts with activity of knowledge acquisition that will continue during the whole development process. Most of the knowledge will be acquired in the beginning of the process; needed amount of new knowledge is declining according to the development process proceeds.

Reuse of Resources

We consider ontological and non-ontological resources as stated above. In the development process of state IS domain ontologies both types of resources could be used. Reuse of non-ontological resources is most important at the stages of ontology specification and conceptualization. Reuse of ontological resources is not possible only during specification and conceptualization but also during the implementation activity. For example, ontology import is a part of implementation of ontology.

Resource reuse activities are dependent on its type as follows.

In case of non-ontological resources first resource reuse is performed and then resource reengineering activity is carried out. For example, a domain model of an IS can be easily used for acquiring possible classes to be included to corresponding domain ontology. Descriptions of data objects from the corresponding XMI file can be reused for defining data type properties for individuals of classes.

In the process of non-ontological resource (e.g. database schema) reuse the resource is analyzed with respect to its usability for ontology creation. If reusable resources are found, then reengineering of these resources is carried out. This is the process of transforming an existing non-ontological resource (e.g. data base schema, database etc.) into ontology that can be reused in the process of ontology engineering of current domain ontology.

In case of ontological resources, reengineering of some existing ontology is performed. An example is geometry ontology that can be reused in a number of ontologies related to the domain of land IS-s.

Process of ontology reuse can be divided into the following activities: 1. Retrieval of possible candidate ontologies from public ontology repositories like Swoogle9 and WATSON 10 . Ontologies developed for Estonian state IS can be retrieved from RIHA 11 . 2. Evaluation of retrieved candidate ontologies from the point of view of requirements (content, language, formal representation, documentation, quality, etc). 3. Choice of suitable ontology 4. Deciding a way how ontology is to be reused. Ontology can be reused as it is.

Ontology might need reengineering before it can be reused. Ontology reengineering is the process during what its conceptual model is transformed into a new conceptual model that meets requirements of a new ontology and which is then implemented. Ontology could also be merged to a new ontology.

Specification

In parallel with knowledge acquisition a set of requirements that ontology should meet are to be defined. In the process of specification activity, goal and scope of ontology, resources, and use cases are specified. In addition, a list and descriptions of central domain concepts are provided. For the development process specification helps to stay within the frame of the scope of the problem. For third parties, ontology specification serves as an initial overview of ontology.

Conceptualization and an Early Implementation

Ontology specification activity is followed by ontology conceptualization. During the conceptualization, a conceptual model of ontology that represents domain concepts and relationships between them is created. The conceptual model of ontology should take into account that ontology will be later implemented in OWL language. Ontology conceptualization is carried out according to acquired knowledge of a domain. Ontology conceptualization is followed by ontology implementation activity resulting in ontology description of OWL language. In provided methodology ontology conceptualization and implementation are considered together because iterative life cycle model of ontology development is applied. Therefore, we call implementation stage here as an early implementation.

Different strategies could be used for conceptualization as follows:  Top-down strategy starts from most general domain concepts and step-by-step moves to specific concepts.  Middle out strategy proposes at first to concentrate to a set of basic (central) concepts of a domain and then to move to the direction of their generalization and specialization.  Buttom-up strategy tries to generalize meaning of data fields related to an application/service.

Taking into account that domain ontologies for state IS will be created by domain experts on the basis of their data collections and corresponding IS the middle out conceptualization strategy is the most appropriate. Central concepts can be identified easily by domain experts as these are usually denoted by central terms used to talk about data collection of the corresponding IS. These terms are also used in legislation documents related to IS. Using top-down approach (from legislation terminology to data fields) creates too many concept hierarchy levels to ontology. Bottom-up method makes it hard to generalize from the level of data fields to more general concepts and therefore it takes more time to distinguish between concepts and attributes. This in turn means that development of ontology that satisfies requirements takes more time.

In proposed methodology ontology conceptualization and implementation are divided into sub-activities as follows: 1. Collection of concepts. Central concepts of a domain are identified (for example, 7-10 concepts). Purpose and scope of IS, most often used database fields and service parameters are helpful indicators for identifying central domain concepts of ontology. 2. Concept generalization and specification of one level. Not all concepts of ontology should correspond to input/output parameters of services, there could be concepts that make ontology better understandable for third parties. However, it is recommendable to keep ontology as minimal as possible with respect to its scope. 3. Identification and addition of main relationships. After central concepts and their generalizations and specifications are identified, then the main relationships between these concepts are to be added to ontology. 4. Early implementation. Result of ontology implementation is its description in OWL. Early implementation enables to detect logical errors of ontology description as well as get a view of its complexity and see how well it meets the requirements. As a rule, ontology creation tools like Protégé12 are used. These tools include built-in DL reasoners (for example, Pellet 13 , Fact++ 14 etc) in order to automatically find inconsistencies in ontology description presented in OWL. 5. Iterative development. As the main goal of ontology its to cover all concepts related to input/output parameters of services, then during consecutive iterations all service parameters will be taken into account and corresponding to them concepts are identified and step-by-step added to ontology. In case of iterative development a set of new concepts to be added to ontology is decreasing making possible to limit development process to implementation activity in the final iteration steps. 6. Addition of datatype properties. As a rule, datatype properties correspond to data objects (database fields like last name, first name, SSN, etc) of a given state IS and are added to the ontology and implemented during final iteration of its development. 7. Annotation of ontology components. After logical consistency of ontology is proved ontology components are to be annotated (e.g. descriptions of natural language(s) are added to components). It is user-friendly to provide a documentation of ontology in addition to its description in the form of machinereadable OWL file. This makes it easier to reuse, maintain and further development of ontology. In order to create conceptual model of ontology it is recommended to use some method of knowledge organization and structuring. Glossary of terms and concepts, concept taxonomy, list of relationships between concepts and attributes of individuals could serve for this purpose. Corresponding activity could be called as documentation of conceptualization of ontology.

Evaluation of the Methodology

The provided methodology has been iteratively developed and evaluated during the last 2 years within the framework of achieving semantic interoperability of state IS in Estonia. The methodology was widely used in numerous training courses on ontology engineering provided for domain experts of state IS-s. The feedback from participants of courses was used to improve the methodology in order to meet needs and take into account background knowledge of domain experts. By now, the methodology is accepted as the ontology development methodology for creation of domain ontologies of state IS in Estonia. During the year 2010, 21 domain ontologies of state IS were developed using this methodology. The complexity of ontologies required for achieving semantic interoperability of state IS as already mentioned is not very high. Domain ontologies of state IS are intended to be used for semantic annotation of web services and as a rule do not contain descriptions of defined classes. The following table 1 represents some quantitative characteristics of a few typical state IS domain ontologies. It was intention from the very beginning of the ontology development for state IS to keep ontologies as simple as possible in order to make it possible to domain experts to create ontologies of their respective fields. Some of ontologies are not entirely finalized as more datatype properties are to be added in order to meet requirements of semantic annotations of web services. According to the law, domain ontologies are to be collected to RIHA repository. However, not all of them are there. In 2010, only 7 ontologies were published. A quality assurance procedure of ontologies to be stored in RIHA has put in place and before ontology does not meet respective requirements, it is not published in RIHA.

The methodology proposed in this paper aimed at development of ontology network of state IS domain ontologies. With this respect RIHA serves as ontology repository for ontology reuse and re-engineering. The SEHKE tool [START_REF] Tomingas | Semantic Interoperability Framework for Estonian Public Sector's E-Services Integration[END_REF] is intended to support collaborative ontology development and managing network of ontologies.

State IS in Estonia has according to RIHA over 20 000 data objects. These should be annotated using corresponding ontology components (i.e. datatype properties). Consequently, the ontology network should contain approximately the same number of datatype properties in addition to concepts and object properties. By now, we have about 500 datatype properties defined in our current version of the ontology network. According to this, we are in the beginning of development of ontology network of state IS in Estonia.

These data objects are used by about 1500 X-road services (machine-to-machine data services) which input/output parameters should be semantically annotated. This process has just started.

Conclusion

Demand for state IS domain ontologies to be used for solving semantic interoperability problems of e-government services requires easier process of creating ontologies than general technically complex ontology development methodologies provide. In this paper we presented a novel ontology development methodology for domain experts who being actual domain knowledge holders easily identify central domain concepts and using early implementation and iterative development activity could build ontologies without need for ontology engineer. The approach is evaluated by development of network of e-government domain ontologies of state IS in Estonia.

Lessons learned from the use of the methodology show that implementation activity is sometimes still too complex for domain experts even if they use easy-to-use ontology editors. Therefore, the future work is planned to make this ontology development methodology even easier by using simple intermediate representations of domain conceptualization that can be automatically translated to OWL ontology. In this case, implementation activity of provided methodology will be automatic or will be at least semi-automatic.

Fig. 1 .

 1 Fig. 1. Development process of domain ontologies for state IS: sequence of activities Ontology management and support activities are performed in parallel with other ontology development activities during the whole ontology development process.

Table 1 .

 1 Ontology metrics of some state IS ontologies

	Name of ontology	Count	Object	Data-type	Subclass	DL expressivity
		of	properties	properties	axioms
		classes
	Address objects	17	13	48	17	ALCQ(D)
	Central commercial	101	39	147	100	ALQOIQ(D)
	register
	Mineral deposits	25	19	133	12	ALCQ(D)
	Estonian	159	9	39	158	ALCRQ(D)
	topographic domain
	Estonian geodetic	16	23	58	0	ALU(D)
	domain

http://www.digitpa.gov.it

http://semic.eu/about_semantic_interoperability_centre_europe.html

OWL DL, www.w3.org/TR/owl-guide

SOAP standard, http://www.w3.org/TR/soap12-part1/#intro

WSDL, http://www.w3.org/TR/wsdl

SAWSDL, http://www.w3.org/TR/sawsdl/

XMI, http://www.omg.org/spec/XMI/

https://riha.eesti.ee/riha/onto/ettevotlus.ariregister/2010/r2

Swoogle; http://swoogle.umbc.edu/

Watson; http://watson.kmi.open.ac.uk/WatsonWUI/

RIHA; http://riha.eesti.ee

Protégé; http://protege.stanford.edu/

Pellet; http://www.clarkparsia.com/pellet

Fact++; http://owl.man.ac.uk/factplusplus

Acknowledgments. This research was partially supported by the target-financed theme No. 0322709s06 of the Estonian Ministry of Education and Research as well as by the ERDF funded Estonian Centre of Excellence in Computer Science, EXCS. I am particularly grateful to Leive Turi for creating the first ontology using this methodology and collaborating to the development of the methodology.