• The KIPS Transactions:PartD
• /
• v.14D no.6
• /
• pp.675-688
• /
• 2007

Memory access errors are frequently occurred in C programs. A number of tools and research works have been trying to detect the errors automatically. However, they have one or more of the following problems: inability to detect all memory errors, changing the memory allocation mechanism, incompatibility with libraries, and excessive performance overhead. In this paper, we suggest a new method to solve these problems, and then present a result of comparison to the previous research works through the experiments. Our approach consists of two phases. First is to transform source code at compile time through inserting instrumentation into the source code. And second is to detect memory errors at run time with a bitmap that maintains information about memory allocation. Our approach has improved the error detection abilities against the binary code analysis based ones by using the source code analysis technique, and enhanced performance in terms of both space and time, too. In addition, our approach has no problem with respect to compatibility with shared libraries as well as does not need to modify memory allocation mechanism.

• KIPS Transactions on Computer and Communication Systems
• /
• v.6 no.5
• /
• pp.219-230
• /
• 2017

General-Purpose Graphics Processing Units (GPGPUs) build massively parallel architecture and apply multithreading technology to explore parallelism. By using programming models like CUDA, and OpenCL, GPGPUs are becoming the best in exploiting plentiful thread-level parallelism caused by parallel applications. Unfortunately, modern GPGPU cannot efficiently utilize its available hardware resources for numerous general-purpose applications. One of the primary reasons is the inefficiency of existing warp/thread block schedulers in hiding long latency instructions, resulting in lost opportunity to improve the performance. This paper studies the effects of hardware thread scheduling policy on GPGPU performance. We propose a novel warp scheduling policy that can alleviate the drawbacks of the traditional round-robin policy. The proposed warp scheduler first classifies the warps of a thread block into two groups, warps with long latency and warps with short latency and then schedules the warps with long latency before the warps with short latency. Furthermore, to support the proposed warp scheduler, we also propose a supplemental technique that can dynamically reduce the number of streaming multiprocessors to which will be assigned thread blocks when encountering a high contention degree at the memory and interconnection network. Based on our experiments on a 15-streaming multiprocessor GPGPU platform, the proposed warp scheduling policy provides an average IPC improvement of 7.5% over the baseline round-robin warp scheduling policy. This paper also shows that the GPGPU performance can be improved by approximately 8.9% on average when the two proposed techniques are combined.

• Journal of Digital Convergence
• /
• v.17 no.8
• /
• pp.379-384
• /
• 2019

This study is an online survey user experience study. The purpose of this research is user experience research to make use and development of online surveys. In-depth interviews were conducted with 8 native Koreans who were not experienced with Naver and Google, and were surveyed using Peter Morville's Honeycomb model. In addition, we performed evaluation through tasks and think-aloud. Naver is highly useful, usable, desirable and findable, and Google can confirm its superior accessible and flexible. Research has shown that improvements in usability and ease of functioning are needed by reclassifying and moving menu categories. Online survey user experience that has not been studied previously can predict the direction of usability improvement and can help the user side. We hope that this research will improve the usability of online surveys, and will lead to various related research.

• 한국HCI학회:학술대회논문집
• /
• 2006.02b
• /
• pp.296-301
• /
• 2006

한국향토문화전자대전은 각 지방의 역사와 문화 유산을 비롯하여, 정치 경제사회의 변화 발전상에 관한 모든 정보를 집대성한 지역 문화 콘텐츠 디지털 백과사전을 말한다. 본 연구는 국내 각 지방의 지역 문화 콘텐츠를 디지털 정보시스템으로 구축함에 있어 적합한 인터페이스의 개발을 위해 진행된 시범 서비스의 사용성 평가에 관한 연구이다. 2003 년 6 월부터 2004 년 12 월까지 경기도 성남시 지역을 대상으로 개발된 디지털성남문화대전에 대하여 전반적인 서비스 및 시스템, 인터페이스 등에 대하여 사용성 평가를 실시하였다. 12 개의 콘텐츠 접근방법에 대하여 5 명의 피실험자를 대상으로 한 자유테스트와 15 개의 태스크로 실험된 수행도 평가를 진행하였다. 4 명의 인터뷰 참여자를 대상으로 FGI 를 실시하고, 테스트의 모든 참여자를 대상으로 한 설문조사를 통해 전반적인 만족도와 선호도를 분석하였다. 평가 대상 서비스에 대한 시스템, 사용자, 인터페이스, 콘텐츠 영역으로 나누어 문제점을 도출하였으며, 이는 시스템 설계와 세부적인 인터페이스 개선에 제안되었다. 특히 평가 결과 도출된 네이밍의 문제와 사용자 가이드, 메뉴 및 네비게이션 체계 등 인터페이스 설계에 대한 개선은 향후 10 년 동안 구축 될 한국향토문화전자대전을 기획하는데 실증적 기초 연구자료가 될 것으로 기대된다. 이는 구체적으로 2005 년 청주지역 및 지속적으로 개발되어가는 사업의 서비스, 인터페이스 기획 및 개발에 기초 가이드라인으로 사용되고 있다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.2
• /
• pp.220-225
• /
• 2010

This paper deals with the robust stability analysis of STATCOM (Static Synchronous Compensator) power system for power quality enhancement and power system stability. The STATCOM plays an important role in controlling the reactive power flow to the power network and hence the system voltage fluctuations and stability. The control areas of this plant are very large and the overall composition of the system is nonlinear. Also, STATCOM is influence of the uncertainties so that it is necessary to apply the new control technique. For solving these problems, we perform the fuzzy modeling and robust analysis for STATCOM system.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.20 no.4
• /
• pp.106-114
• /
• 2012

As Incheon International Airport(IIA) is located in an island 50-km away from Seoul, various travel equipments for access are required. So far two connecting bridges are constructed funded by civilian funds. For the further bridge construction, the reduction of forecast traffic amount and the government subsidy for the civilian funds are big issues. Comparing the access traffics of IIA to those other competing airports, traffic conditions inside the airport are superior to other competing airports from the management point of view, as utilization conditions and equipment capacities are periodically monitored and evaluated to set up comprehensive countermeasures following constructing by stages. However, while the accessability to IIA is very important, as IIA is built on an island the conflicts between near-by developers and traffic facility operators make further bridge construction difficult. As improving the accessibility to an airport is not easy to achieve only by the IIA management's efforts, the central government level authorities should organize a committee with agencies concerned and analyze the characteristics of access traffic periodically to suggest reform measures for each organization concerned to implement appropriate undertakings at apt timing. For the future, central government's level empirical research on the airport accessibility for synthetic and systematic plan set-up is expected.

• Journal of the Korean Society for Railway
• /
• v.13 no.1
• /
• pp.125-130
• /
• 2010

The government makes an effort to disperse the centralization of Seoul through the its surroundings development for relieving the various social problems caused by the capital region concentration. But, the planless rail system development in the capital region have made it difficult to approach into Seoul city center from its surroundings. Through Seoul metro line 9, constructed by private company first in Korea, that has operation plan with normal and express train together, we would like to study up on promotion of passenger service quality such as "the improvement of the accessibility to Seoul city center from its surroundings" and "service of various pattern of trains".

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.8A
• /
• pp.779-785
• /
• 2002

This paper presents a phase-based stereo matching algorithm in order to efficiently extract 3-dimensional objects from two 2D images. Conventional phase-based methods, especially using windowed Fourier phases, inherit good properties in the case of hierarchical approaches, because they basically use a multi-resolution phase map. On the contrary, their computational costs are very heavy. Therefore, a fast hierarchical approach, using multi-resolution phase-based strategy and reducing the redundancy of phase calculations, is proposed in this pare. In addition, a structural matching algorithm on the phase domain is adopted to improve the matching quality. In experimental results, it is shown that the computation loads are considerably reduced about 8 times and stable outputs are obtained.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.7
• /
• pp.696-708
• /
• 1992

In this study, we have several objectives. First, In spite of a fixed bandwidth waste of reservation channel, we maximize the efficiency of transmission channel by the multiple access algorithm that performs channel reservation and data transmission independently, eliminating the frame structure of transmission channel and reserving it by the slot unit . Second, In order to improve the entire system performance, we accommodate the variation of traffic at each earth station more effectively, and accomplish the stable delay characteristics and the equlity of service #or users. For this purpose, we design the satellite channel that consists of reservation channel and transmission channel which are logically separate and operate Independently. We also design a demand assignment multiple access algorithm based on the satellite channel structure.

• Annual Conference of KIPS
• /
• 2001.04a
• /
• pp.47-50
• /
• 2001

본 논문은 워크플로우 관리 시스템 중 Workflow Management Coalition (WfMC)의 명세서의 WfMC 참조 모델 중 인터페이스 3 에 해당하는 런타임 클라이언트와 워크플로우 엔진과의 상호작용에 기술하였다. 명세서를 통해서 발생되는 문제점을 검토 후 이에 대한 문제해결 방법으로 기존의 접근방법과 다르게 XML 기반의 응용프로그램 호출 메커니즘을 통해서 프로세스의 오버헤드를 줄이고 엔진과의 API 를 통하지 않고도 쉽게 응용프로그램 개발을 할 수 있게 했다. 또한 B2C/B2B로 대변되는 전자상거래 및 전자시장(E-Market Place)의 활성화가 급속하게 확장됨에 따라 개선된 응용프로그램의 호출방법으로 XML 기반 접근방법을 제시한다. 또한 워크플로우 관리 시스템에서 중요한 요소인 상호운용성에서도 이러한 XML 기반 응용프로그램 호출은 워크플로우 관리 시스템간 상호운용성에도 중대한 영향을 줄 수 있게 되는 것이다. 또한 인터넷이라는 환경을 위해 XML 을 사용하여 기존의 접근방법에서부터 많은 변화를 가져올 수 있는 것이다.