• Nuclear Engineering and Technology
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• v.31 no.3
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• pp.344-363
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• 1999

A multi-dimensional thermal-hydraulic system analysis code, MARS 1.3.1, has been developed in order to have the realistic analysis capability of two-phase thermal-hydraulic transients for pressurized water reactor (PWR) plants. As the backbones for the MARS code, the RELAP5/MOD3.2.1.2 and COBRA-TF codes were adopted in order to take advantages of the very general, versatile features of RELAP5 and the realistic three-dimensional hydrodynamic module of COBRA-TF. In the MARS code, all the functional modules of the two codes were unified into a single code first. Then, the source codes were converted into the standard Fortran 90, and then they were restructured using a modular data structure based on "derived type variables" and a new "dynamic memory allocation" scheme. In addition, the Windows features were implemented to improve user friendliness. This paper presents the developmental work of the MARS version 1.3.1 including the hydrodynamic model unification, the heat structure coupling, the code restructuring and modernization, and their verifications.their verifications.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.2
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• pp.167-178
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• 2000

Software RAID(Redundant Arrays of Inexpensive Disks) is defined as a storage system that provides capabilities of hardware RAID, and guarantees high reliability as well as high performance. In this paper, we propose an enhanced disk scheduling algorithm and a scheme to guarantee reliability of data. We also design and implement software RAID by utilizing these mechanism to develop a storage system for multimedia applications. Because the proposed algorithm improves a defect of traditional GSS algorithm that disk I/O requests arc served in a fixed order, it minimizes buffer consumption and reduces the number of deadline miss through service group exchange. Software RAID also alleviates data copy overhead during disk services by sharing kernel memory. Even though the implemented software RAID uses the parity approach to guarantee reliability of data, it adopts different data allocation scheme. Therefore, we reduce disk accesses in logical XOR operations to compute the new parity data on all write operations. In the performance evaluation experiments, we found that if we apply the proposed schemes to implement the Software RAID, it can be used as a storage system for small-sized video-on-demand servers.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.151-163
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• 2013

Recently the attention on digital hologram that is regarded as to be the final goal of the 3-dimensional video technology has been increased. Digital hologram is calculated by modeling the interference phenomenon between an object wave and a reference wave. The modeling for digital holograms is called by computer generated hologram (CGH) Generally, CGH requires a very large amount of calculation. So if holograms are generated in real time, high-speed method should be needed. In this paper, we analyzed CGH equation, optimized it for mapping general purpose graphic processing unit (GPGPU), and proposed a optimized CGH calculation technique for GPGPU by resource allocation and various experiments which include block size changing, memory selection, and hologram tiling. The implemented results showed that a digital hologram that has $1,024{\times}1,024$ resolution can be generated during approximately 24ms, using 1K point clouds. In the experiment, we used two GTX 580 GPGPU of nVidia Inc.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1027-1059
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• 2005

The purpose of this paper is to analyze the dynamic characteristics of innovation sources such as scientific knowledges, processing technologies and user's needs in advanced metals technology. The journal articles data of four advanced materials are analyzed; amorphous metals, superplastic materials, shape memory alloys and aluminum-lithium alloy. Some regularities are found from the analysis of the four materials. The innovation proceeds through close interactions among the innovation sources. As the innovation proceeds, the relative importance of each source changes: scientific knowledge initiates the innovation and becomes the most important source in the first phase, then the processing technologies increase importance in the second phase, and then scientific knowledge, again, becomes the leading factor of innovation. Scientific knowledge and processing technology take turns leading the innovation. The impacts of users' needs to the innovation increase more and more as innovation proceeds. The results of analysis imply to the policy makers that emphasis of policy, and therefore the allocation of sources for innovation, should vary along the phases in the life cycle of advanced metals technology.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.19-24
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• 2009

When a dynamic method is applied at the time of occurrence of an client's connection request for most of the online gaming server engine, the gaming server is processing a session connection, it's initialization. Yet, such a method will cause a lot of loading and bottle-neck in the gaming server at the same time. Therefore we propose the object polling scheme to minimizes a memory fragmentation and loading of the initialization on the client using a static allocation method for an efficient On-lin gaming serverin this paper. We implement the gaming server applying to our proposed scheme, and we show an improvement in our proposed scheme by performance analysis in this paper.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.5
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• pp.36-42
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• 1980

In this study, multi-microprocessors system in which slave microprocessor is conrlected with master microprocessor bus through the DMA controller is designed by the use of four 8085 CPU. A high degree of processing efficiency could be obtained by making this system work parallel processing. The result of measuring relat ions bet ween working microproressor and system throughput was 70-80 percents lower than ideal value Master microprocessor takes charge of resource allocation and scheduling, common memory assigns communication between microprocessors and a store of common data. The met hod of detecting Pa rallelism from source Program composed by series is also suggested.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.9
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• pp.531-538
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• 2005

This paper proposes an expert system which is able to enhance the accuracy and productivity by determining the test strategy based on heuristic rules for test of the hybrid electronic circuit board producted massively in production line. The test heuristic rules are obtained from test system designer, test experts and experimental results. The guarding method separating the tested device with circumference circuit of the device is adopted to enhance the accuracy of measurements in the test of analog devices. This guarding method can reduce the error occurring due to the voltage drop in both the signal input line and the measuring line by utilizing heuristic rules considering the device impedance and the parallel impedance. Also, PSA(Parallel Signature Analysis) technique Is applied for test of the digital devices and circuits. In the PSA technique, the real-time test of the high integrated device is possible by minimizing the test time forcing n bit output stream from the tested device to LFSR continuously. It is implemented in Visual C++ computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique, the interface with the electronic circuit database and the hardware direct control. Finally, the effectiveness of the builded expert system is proved by simulating the several faults occurring in the mounting process the electronic devices to the surface of PCB for a typical hybrid electronic board and by identifying the results.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.11
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• pp.1457-1463
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• 1999

This paper develops an real-time expert system for the electronic interlocking system. it obtains the higher safety by determining the railway interlocking strategy in order to prevent trains from colliding, and derailing in the viewpoint of veteran expert, considering the situation of station in real-time. The expert system determines the real-time interlocking strategy by confirming the interlocking relationships among signal facilities based on the interlocking knowledge base from input information such as signal, points, and it is implemented as the rule-based system in order to represented accurately and effectively the interlocking relationships. Especially in case of emergency the function which determines the rational route coordinating with IIKBAG on the workstation is designed in order to minimize the spreading effect. It is implemented in C computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique, the build and interface of the station structure database. And, the validity of the built expert system is proved by simulating the diversity cases which may occur in the real system for the typical station model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.6
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• pp.1375-1382
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• 2019

The latest version of commercial protector, Themida, has been updated, it is impossible to apply a normalized unpacking mechanism from previous studies by disable the use of a virtual memory allocation that provides initial data to be tracked. In addition, compared to the previous version, which had many values that determined during execution and easy to track dynamically, it is difficult to track dynamically due to values determined at the time of applying the protector. We will look at how the latest version of Themida make it difficult to normalize the API wrapping process by adopted techniques and examine the possibilities of applying the unpacking techniques to further develop an automated unpacking system.

• Journal of the Korea Society of Computer and Information
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• v.17 no.2
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• pp.149-157
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• 2012

In this thesis, the problem of computing approximate answers to continuous sliding-window joins over data streams when the available memory may be insufficient to keep the entire join state. One approximation scenario is to provide a maximum subset of the result, with the objective of losing as few result tuples as possible. An alternative scenario is to provide a random sample of the join result, e.g., if the output of the join is being aggregated. It is shown formally that neither approximation can be addressed effectively for a sliding-window join of arbitrary input streams. Previous work has addressed only the maximum-subset problem, and has implicitly used a frequency based model of stream arrival. There exists a sampling problem for this model. More importantly, it is shown that a broad class of applications for which an age-based model of stream arrival is more appropriate, and both approximation scenarios under this new model are addressed. Finally, for the case of multiple joins being executed with an overall memory constraint, an algorithm for memory allocation across the join that optimizes a combined measure of approximation in all scenarios considered is provided.