• 한국정보통신학회논문지
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• 제3권4호
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• pp.723-736
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• 1999

컴파일러의 코드 최적화(code optimization)는 생성되는 기계 코드의 실행 시간을 감소시키고 기억장소 크기를 감소시키기 때문에 매우 중요한 단계이다. 본 연구에서는 튜플(tuple) 형태의 중간코드에서 제어 및 자료 흐름 분석(control and data flow analysis)을 수행하여 프로그램의 흐름 분석 정보를 얻어 각종 최적화를 수행하는 최적화기(optimizer)를 구현하였다. 또한, 각 최적화기들이 수행한 최적화 정도를 비교 분석하고 최적화기들 상호간의 의존성을 분석하였다. 따라서, 컴파일러 최적화 단계에서 우선적으로 수행할 최적화기를 선택 문제를 해결하구 상호간의 의존도로부터 최적화들간의 순서를 정할 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권5호
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• pp.695-702
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• 2010

Numerical analysis information will be very useful to improve fluid system. General information about an internal gas flow is presented by numerical analysis approach. Relating with hydrogen compressing system, which have an important role in hydrogen energy utilization, this should be a useful tool to observe the flow quickly and clearly. Flow characteristic analysis, including pressure and turbulence kinetic energy distribution of hydrogen gas coming to the cylinder of a reciprocating compressor are presented in this paper. Suction-passage model is designed based on real model of hydrogen compressor. Pressure boundary conditions are applied considering the real condition of operating system. The result shows pressure and turbulence kinetic energy are not distributed uniformly along the passage of the Hydrogen system. Path line or particles tracks help to demonstrate flow characteristics inside the passage. The existence of vortices and flow direction can be precisely predicted. Based on this result, the design improvement, such as reducing the varying flow parameters and flow reorientation should be done. Consequently, development of the better hydrogen compressing system will be achieved.

• International journal of advanced smart convergence
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• 제9권1호
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• pp.141-153
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• 2020

This study aims to understand the antecedents and consequences of flow experience in online movie information sharing behavior of young Chinese moviegoers residing in Korea to explore a potential market. We followed the Stimulus-Organism-Response (S-O-R) theory and flow theory approaches for developing measures of constructs and investigated previous related studies. This study collected 186 data from Chinses students who attend Korean university. Statistical analysis revealed that information seeking behavior and telepresence are related to online flow experience. In addition, the online flow experience affected consumer satisfaction and information sharing behavior. Flow experience also has been predicted the mediation effect between stimulus information seeking behavior, telepresence and satisfaction and information sharing behavior. Our research findings offer insights for marketers in the movie distribution business who are interested in a better understanding of the behaviors of Chinese moviegoers residing in Korea

• Journal of Advanced Marine Engineering and Technology
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• 제32권8호
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• pp.1201-1207
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• 2008

Numerical analysis information will be very useful to improve fluid system. General information about an internal gas flow is presented by numerical analysis approach. Relating with hydrogen compressing system, which have an important role in hydrogen energy utilization, this should be a useful tool to observe the flow quickly and clearly. Flow characteristic analysis, including pressure and turbulence kinetic energy distribution of hydrogen gas coming to the cylinder of a reciprocating compressor are presented in this paper. Suction-passage model is designed based on real model of hydrogen compressor. Pressure boundary conditions are applied considering the real condition of operating system. The result shows pressure and turbulence kinetic energy are not distributed uniformly along the passage of the Hydrogen system. Path line or particles tracks help to demonstrate flow characteristics inside the passage. The existence of vortices and flow direction can be precisely predicted. Based on this result, the design improvement, such as reducing the varying flow parameters and flow reorientation should be done. Consequently, development of the better hydrogen compressing system will be achieved.

• Journal of Mechanical Science and Technology
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• 제15권3호
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• pp.300-308
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• 2001

Tracking of moving objects within video streams is a complex and time-consuming process. Large number of moving objects increases the time for computation of tracking the moving objects. Because of large computations, there are real-time processing problems in tracking of moving objects. Also, the change of environment causes errors in estimation of tracking information. In this paper, we present a new method for tracking of moving objects using optical flow motion analysis. Optical flow represents an important family of visual information processing techniques in computer vision. Segmenting an optical flow field into coherent motion groups and estimating each underlying motion are very challenging tasks when the optical flow field is projected from a scene of several moving objects independently. The problem is further complicated if the optical flow data are noisy and partially incorrect. Optical flow estimation based on regulation method is an iterative method, which is very sensitive to the noisy data. So we used the Combinatorial Hough Transform (CHT) and Voting Accumulation for finding the optimal constraint lines. To decrease the operation time, we used logical operations. Optical flow vectors of moving objects are extracted, and the moving information of objects is computed from the extracted optical flow vectors. The simulation results on the noisy test images show that the proposed method finds better flow vectors and more correctly estimates the moving information of objects in the real time video streams.

• 한국컴퓨터정보학회논문지
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• 제23권12호
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• pp.89-94
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• 2018

In this paper, we implemented a static analysis tool for weakness. We implemented on JavaCC using syntax information and control flow information among various information. We also tested the performance of the tool using Juliet-test suite on Eclipse. We were classified using information necessary for diagnosis and diagnostic methods were studied and implemented. By mapping the information obtained at each compiler phase the security weakness, we expected to link the diagnostic method with the program analysis information to the security weakness. In the future, we will extend to implement diagnostic tools using other analysis information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.4825-4847
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• 2016

In this paper, we focus on the per-flow throughput analysis of IEEE 802.11 multi-hop ad hoc networks. The importance of an accurate saturation throughput model lies in establishing the theoretical foundation for effective protocol performance improvements. We argue that the challenge in modeling the per-flow throughput in IEEE 802.11 multi-hop ad hoc networks lies in the analysis of the freezing process and probability of collisions. We first classify collisions occurring in the whole transmission process into instantaneous collisions and persistent collisions. Then we present a four-dimensional Markov chain model based on the notion of the fixed length channel slot to model the Binary Exponential Backoff (BEB) algorithm performed by a tagged node. We further adopt a continuous time Markov model to analyze the freezing process. Through an iterative way, we derive the per-flow throughput of the network. Finally, we validate the accuracy of our model by comparing the analytical results with that obtained by simulations.

• 경영과학
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• 제30권1호
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• pp.149-165
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• 2013

This study empirically investigated the changes of performance evaluation systems under the environment of supply-chain e-commerce. The objectives of e-commerce include obtaining financial profit, internal innovation through processes integration, learning with information flow, and customer satisfaction through quick response. These objectives are generally consistent with the four evaluation measures of balanced scorecard(BSC). This study, first, demonstrated that perceived environmental uncertainty(PEU) has a significant effect on the adoptions of e-commerce and BSC, and severe competition positively influences the use of e-commerce. With cluster analysis and subgroup analysis, we also showed that under the high adoption levels of e-commerce, the high utilization of BSC can improve the supply-chain performance of a firm. In addition, it was found that the use of e-commerce indirectly and significantly affects supply-chain performance through inter-organizational information flow, and the supply-chain performance of a firm leads to the improvement of organizational performance.

• 제어로봇시스템학회논문지
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• 제18권2호
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• pp.110-117
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• 2012

This paper describes a new design of optical flow estimation system with three cameras. Optical flow provides useful information of camera movement; however a unique solution is not usually available for unknowns including the depth information. A camera and two tilted cameras are used to have different view of angle and direction of movement to the camera axis. Geometric analysis is performed for cases of several independent movements. The ideas of taking advantage of the extra information for robot navigation are discussed with experimental results.

• 산업경영시스템학회지
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• 제23권56호
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• pp.35-43
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• 2000

In order to obtain rigorous systems analysis and design, it is essential to understand accurate information flow in the system. For the effective capturing of accurate information flow in a system, it Is vital to control information flow in the system. Also, information and information flow have to be simplified as a deliverable form. This paper presents partitioning and conveyance technique based on the application of situation theory. First, historical background of situation theory will be given. Then necessary conditions and definitions will be provided. Lastly, this paper provides specific technique with example. This introduced technique will be a powerful tool for sharing timely and relevant information in a complex manufacturing system that can be used continuously and efficiently throughout systems operation.