• International Journal of Concrete Structures and Materials
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• v.4 no.2
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• pp.77-87
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• 2010

Prestressed concrete (PSC) I-type girders have been used for span length around up to 40 m in domestic region. PSC girders are very cost effective girder type and extending their lengths more than 50 m will bring large benefit in cost. A new design method was proposed by combining two notable design concept in order to extend the applicable span length in this study. First of all, several numbers of openings was introduced in the girder web, and half of the anchorage devices were moved into the openings. In this way, large compressive stress developed at end zone was reduced, and the portion of design load coming from self-weight was reduced as well. Secondly, prestressing force was introduced in the girder not once at the initial stage, but through multiple loading stages. A full scale girder with the length of 50 m with the girder depth of 2 m was fabricated, and a flexural test was conducted in order to verify the performance of newly developed girder. Test results showed that the new holed web design concept can provide a way to design girders longer than 50 meters with the girder height of 2 m.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.1
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• pp.171-178
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• 1999

Despite of decrease in shear and moment strengths, most steel structural designers use web openings in beams because of economical benefit and requirement. The purpose of this study is to suggest the method of reinforcement of H-shape steel beams with a rectangular web opening. If shear predominates over bending, it is necessary to consider all possible combinations of shear force and bending moment acting at the opening. In this paper, the ultimate strength and behavior of perforated beams have been investigated according to parameters (ratio of M/V, opening width within opening height ratio D/h, various reinforcing types A/B/C/D/M/N/W). The results of this study are as follows ; 1. Deformation of H-shape steel beams with a rectangular web opening was greatly affected by not only bending but also shear. 2. SB1-2/3 series have little difference in the reinforced efficiency, but SB1-2E/3E series have difference in the reinforced efficiency according to the reinforcement type. 3. Efficiency of SB1-2E/3E series is determined by reinforcing types, which RB1-2E-B/M/C and RB1-3E-M/D/C specimens have good efficient. Reinforcing type of perforated beams chooses efficient method according to ratio of M/V and D/h.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.834-836
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• 2003

Recently, web services concept is rapidly rising as new solution to solve the integration problem among heterogeneous application systems . This web servic es concept is adaptable in the field of 4S application systems integration that handles the spatial information of GIS, SIIS, GNSS and ITS. So, this paper suggests a new 4S web services model for the infrastructures of nationwide spatial clearinghouse, which is mainly based on the OGC and W3C web services specifications. Conclusively, this proposed model that could serve various spatial data and services has some advantages of being flexibly and powerfully capable of integrating the 4S application systems owing to adapting the international standard specifications of OGC and W3C.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.166-173
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• 1999

Al forged parts are many cases with rib-web section which is difficult to manufacture precisely. Therefore, process conditions must be optimized for precision forging of Al alloys. In this study, various process parameters such as die design, lubricant, ram speed, forging temperature have been investigated using the experiment, upper bound theory and F.E.M. simulation to develop the precision forging technology for rib-web shape component. When lubricant is applied to both material and die, shear friction factor is 0.1 which shows best effect of lubricant. It is specific corner radius of die that minimized forging load regarding process conditions, especially according to the ratio of the width of rib and web. In conclusion, optimum corner radius is 2~3mm when the width of rib and web is 3mm and 20mm respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.94-97
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• 2009

본 연구에서 개발한 UPC(Ubiquitous Personal Computer)는 무선 네트워크를 지원하는 모바일 폰을 이용하여 언제 어디서든 PC의 자원을 사용할 수 있는 기술로서, 모바일 폰은 WebDAV 프로토콜을 이용하여 WebDAV 서버자원(PC의 자원)을 관리하며, GUI 환경의 간편한 사용자 인터페이스를 제공한다. 사용자는 구현된 인터페이스와 WebDAV 기본 메소드를 이용하여 PC에 자원을 등록하고, PC 자원에 대하여 열람, 검색, 삭제, 업로드, 다운로드 등을 제공한다. 이와 같은 시스템은 휴대용 기기(PDA, 모바일 폰)의 저장 공간 한계를 극복하는 하나의 해결책이 될 수 있다. 개발되어진 UPC를 적용 모델은 삼성 Anycall SCH-M470을 이용하였으며 일차적으로는 에뮬레이터를 이용하여 실험을 거쳤고 이 실험을 바탕으로 솔루션을 SCH-M470모델에 배포하여 실험 및 검증을 하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.586-589
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• 2012

Web Services have been utilized in a wide variety of applications and have turned into a key technology in developing business operations on the Web. Originally, Web Services can be exploited in an isolated form, however when no single Web Service can satisfy the functionality required by a user, there should be a possibility to compose existing services together in order to fulfill the user requirement. However, since the same service may be offered by different providers with different non-functional Quality of Service (QoS), the task of service selection for Web Service composition is becoming complicated. Also, as Web Services are inherently unreliable, how to deliver reliable Web Services composition over unreliable Web Services should be considered while composing Web Services. In this paper, we propose an approach on a QoS-aware Web Service selection for reliable Web Service composition. In our approach, we select and classify Web Services using Decision Tree based on QoS attributes provided by the client. Service classifier will improve selection of relevant Web Services early in the composition process and also provide flexibility to replace a failed Web Services with a redundant alternative Web Services, resulting in high availability and reliability of Web Service composition. We will provide an implementation of our proposed approach along with efficiency measurements through performance evaluation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1708-1727
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• 2021

In the advent of the twenty-first century, human beings began to closely interact with technology. Today, technology is developing, and as a result, the world wide web (www) has a very important place on the Internet and the significant task is fulfilled by Web services. A lot of Web services are available on the Internet and, therefore, it is difficult to find matching Web services among the available Web services. The recommendation systems can help in fixing this problem. In this paper, our observation was based on the recommended method such as the collaborative filtering (CF) technique which faces some failure from the data sparsity and the cold-start problems. To overcome these problems, we first applied an ontology-based clustering and then the k-nearest neighbor (KNN) algorithm for each separate cluster group that effectively increased the data density using the past user interests. Then, user ratings were predicted based on the model-based approach, such as singular value decomposition (SVD) and the predictions used for the recommendation. The evaluation results showed that our proposed approach has a less prediction error rate with high accuracy after analyzing the existing recommendation methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.763-764
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• 2012

Web Services are considered to be a promising technology to add a new level of functionality to the existing World Wide Web. However, despite the growing use of Web Services by many organizations, there are several issues that are slowing their deployment such as service discovery, recovery from faults and security. In this paper, we give a detailed overview of issues surrounding Web Services, discuss existing solutions and describe their limitations.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.1365-1368
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• 2011

The Kalman Filter is one of the most common techniques of tracking mobile user. Web service is a promising method of reusing programs. Therefore, this paper presents our implementation of Kalman Filter web service. There are three ways of implementing a web service system. Ours is Kalman filter as RPC web service.

• Computational Structural Engineering
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• v.23 no.6
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• pp.29-32
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• 2010