• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.05a
• /
• pp.287-293
• /
• 2005

Ubiquitous Computing has introduced one of the most innovative international research contributions on the design and evaluation of new generations of handheld and mobile information appliances. New devices are being invented and existing devices are being improved with smaller size and increased mobility. These changes of computing paradigm are enabling the enterprises' legacy services to be automated and value-added all the more. We suggest a service framework and algorithms of provisioning healthcare services in a ubiquitous computing environment. We construct domain ontology that is related to diabetes and minimum common sense ontology for service composition. The results of this research enable integration and interconnection of devices, applications, and functions of enterprises within the healthcare services.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.24 no.4
• /
• pp.99-113
• /
• 2013

The study investigated the intellectual structure of the library and information science field by journal co-citation analysis on thirty LIS journals with high journal impact factors. Patterns of journal-to-journal citation show the structure of journals in the field, visualized by a networked map of the journals. The result shows journals that can be considered as the core group and as the peripheral group, which corresponds to other studies for investigating the field's intellectual structure using other techniques, such as cluster analysis and multidimensional scaling.

• Journal of Power Electronics
• /
• v.18 no.5
• /
• pp.1434-1447
• /
• 2018

The control design of inductive power transfer (IPT) systems has attracted a lot of attention in the field of wireless power transmission. Due to the high-order resonant networks and multiple loads in IPT systems, a simplified model of an IPT system is preferred for analysis and control design, and a controller with strong robustness is required. Hence, an active disturbance rejection control (ADRC) for IPT systems is proposed in this paper. To realize the employment of ADRC, firstly a small-signal model of an LC series-compensative IPT system is derived based on generalized state-space averaging (GSSA), then the ADRC is implemented in the designed IPT system. The ADRC not only provides superior robustness to unknown internal and external disturbances, but also requires few knowledge of the IPT system. Due to the convenient realization of ADRC, the designed IPT system retains its simple structure without any additional circuits. Finally, a frequency domain analysis and experimental results have validated the effectiveness of the employed ADRC, especially its robustness in the presence of frequency drifts and other common disturbances.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.6
• /
• pp.2277-2287
• /
• 2015

In recent times, multilevel inverters are given high priority in many large industrial drive applications. However, the reliability of multilevel inverters are mainly affected by the failure of power electronic switches. In this paper, open-switch and short-switch failure of multilevel inverters and its identification using a high performance diagnostic system is discussed. Experimental and simulation studies were carried out on five level cascaded H-Bridge multilevel inverter and its output voltage waveforms were analyzed at different switch fault cases and at different modulation index values. Salient frequency domain features of the output voltage signal were extracted using the discrete wavelet transform multi resolution signal decomposition technique. Real time application of the proposed fault diagnostic system was implemented through the LabVIEW software. Artificial neural network was trained offline using the Matlab software and the resultant network parameters were transferred to LabVIEW real time system. In the proposed system, it is possible to precisely identify the individual faulty switch (may be due to open-switch (or) short-switch failure) of multilevel inverters.

• Journal of the Korean Society for information Management
• /
• v.22 no.2 s.56
• /
• pp.41-56
• /
• 2005

For the purpose of extending the Web that is able to understand and process information by machine, Semantic Web shared knowledge in the ontology form. For exquisite query processing, this paper proposes a method to use semantic relations in the ontology as relevance feedback information to query expansion. We made experiment on pharmacy domain. And in order to verify the effectiveness of the semantic relation in the ontology, we compared a keyword based document retrieval system that gives weights by using the frequency information compared with an ontology based document retrieval system that uses relevant information existed in the ontology to a relevant feedback. From the evaluation of the retrieval performance. we knew that search engine used the concepts and relations in ontology for improving precision effectively. Also it used them for the basis of the inference for improvement the retrieval performance.

• Journal of Korean Library and Information Science Society
• /
• v.45 no.2
• /
• pp.311-337
• /
• 2014

This study intends to investigate how many LIS students take a interest in cultural programs offered by local libraries, and whether such a interest leads to actual participation in cultural programs. To the end, surveys and in-depth interviews were conducted on 2nd and 3rd year students from department of Library and Information Science in Busan. The result of this study shows low participation and passive attitude, even though LIS students fully recognize the importance of cultural programs in local libraries. The final suggestions include both educational strategies and practical guidance which might be helpful to attract voluntary participation from prospective librarians and to promote absorption of domain knowledge.

• Journal of KIISE:Databases
• /
• v.27 no.2
• /
• pp.141-150
• /
• 2000

There are three significant drawbacks in extant fuzzy rule-based expert system languages. First, they lack the functionality of composite object inference. Second, they do not support fuzzy reasoning semantically easy to understand and conceptually simple to use. Third, knowledge representation and reasoning style of their model have a great semantic gap with those of current database models. Therefore, it is very difficult for the two models to be seamlessly integrated with each other. This paper provides the formal specification of a fuzzy object inference model to solve the three drawbacks. GIS(Geographic Information System) application domain is used to demonstrate that our model naturally models complex GIS information in terms of composite objects and successfully performs fuzzy inference between them.

• Journal of the Korean Society for information Management
• /
• v.23 no.2
• /
• pp.147-165
• /
• 2006

The explosive growth of Web-based educational resources requires a new approach for accessing relevant information effectively. Social searching in the context of social navigation is one of several answers to this problem, in the domain of information retrieval. It provides users with not merely a traditional ranked list, but also with visual hints which can guide users to information provided by their colleagues. A personalized and context-dependent social searching system has been implemented on a platform called KnowledgeSea II, an open-corpus Web-based educational support system with multiple access methods. Validity tests were run on a variety of aspects and results have shown that this is an effective way to help users access relevant, essential information.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1998.10a
• /
• pp.407-410
• /
• 1998

Configuration is a set of building block processes, a series of selection and combining parts or components which composes a whole thing. A whole thing could be such a configurable object as manufacturing product, network system, financial portfolio, system development plan, project team, etc. Configuration problem could happen during any phase of product life cycle: design, production, sales, installation, and maintenance. Configuration has long been one of cost and time consuming work, because only high salaried technical experts on product and components can do configuration. Rework for error adjustments of configurations at later process causes far much cost and time, so accurate configuration is required. Under the on-line electronic commerce environment, configuration problem solving becomes more important, because component-based sales should be done automatically on the merchant web site. Automated product search, order placement, order fulfillment and payment make that manual configuration is no longer feasible. Automated configuration means that all the constraints among components should be checked and confirmed by configuration engine automatically. In addition, technical constraints and customer preferences like price range and a specific function required should be considered. This paper gives an brief overview of configuration problems: characteristics, representation paradigms, and solving algorithms and introduce CRSP(Constraint and Rule Satisfaction Problem) method. CRSP method adopts both constraint and rule for configuration domain knowledge representation. A survey and analysis on web sites adopting configuration functions are provided. Future directions of configuration for EC is discussed in the three aspects: methodology itself, companies adopting configuration function, and electronic commerce industry.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2000.04a
• /
• pp.261-270
• /
• 2000

개념 계층(Concept Hierarchy)은 데이터베이스 분야에서 사용되는 대표적인 배경 지식(Background Knowledge)으로써, 데이터베이스에 내재되어 있는 구조적인 정보, 데이터의 분포, 영역전문가(Domain Expert)에 의해 주어지는 외부 지식 등이 반영되어 있다. 개념 계층의 특성상 부모(parent)-자식(child) 관계가 있는 두 노드가 있을 때, 한 노드의 값으로부터 다른 노드의 값을 추정할 수 있다. 이 추정된 값을 기대치라고 하고, 한 노드의 값으로부터 추정된 기대치와 실제치가 상당히 상이한 값을 보이는 노드가 있을 때, 이를 흥미롭다(interesting)라고 할 수 있다. 그러나 아직까지 개념계층상에서의 흥미로운 부분 탐색에 대한 연구가 없었으며, 흥미로움(interestingness)의 척도(measurement)에 대한 연구로서는 신뢰도(confidence), 리프트(lift), 컨빅션(conviction)등이 있다. 그러나 이런 흥미도의 척도에 관한 연구도 연관규칙에 한정되어 이루어졌으므로 개념계층상의 데이터에 적용하기 위해서는 약간의 수정 및 새로운 정의가 필요하다. 본 논문에서는 데이터의 특성에 따른 개념계층이 존재할 때, 이를 이용하여 기대치와 실제치가 상이한 흥미로운 부분을 발견하고자 하며, 이를 위하여 개념계층이 존재할 때, 이를 이용하여 기대치와 실제치가 상이한 흥미로운 부분을 발견하고자 하며, 이를 위하여 개념계층상에서의 흥미도의 척도를 제안하고 흥미로운 부분을 탐색하는 방법을 기술하고자 한다. 또한 데이터마이닝의 결과인 연관규칙을 개념계층에 적용하여 연관규칙을 통해 얻어질 수 있는 기대치를, 지지도(support), 신뢰도(confidence), 리프트(lift), 컨빅션(conviction)등의 관계를 통해 다양한 방법으로 모색해본다. 이 연구에서 제안하는 이러한 개념계층상의 흥미로운 부분의 탐색은, 전자 상거래에서의 CRM(Customer Relationship Management)나 틈새시장(niche market) 마케팅 등에 적용가능하리라 여겨진다.