• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.974-978
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• 2002

For the efficient operation of container terminals, it is essential to develop optimal operation rules for marshaling yard and yard cranes. However, derision rules for conventional container terminals expose various limitations to be applied to automated container terminals. This paper introduces a development of a simulation model for evaluating various operation rules for automated transfer cranes (ATCs) and yard operation in the marshaling yard.

• Journal of Korea Water Resources Association
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• v.46 no.4
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• pp.373-387
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• 2013

For the efficient operation and management of the water resources system, coordinated operation of weirs and reservoirs is required. A simulation based, and an optimization based approaches are available to deal with the operation and management problems. The simulation based approach does not guarantee an optimal solution, and the optimization based approach is not so flexible to consider, complex, nonlinear problems we will face when trying to allocate water to different uses, various demand sectors in a basin. Hence, it is important to develop a model that would compensate for the weak points in both models. We will compare and contrast intrinsic and extrinsic properties of two modeling approaches, addressing issues related to setting system operation and control rules that would lead us to more efficient use of water in the basin. As a result, we propose to use CoWMOM(Coordinated weirs and multi-reservoir operating model), a "simulation based" optimization model for a simple simulation of the past periods, and for the real-time simulation process considering uncertain inflow.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1069-1074
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• 2008

This paper presents an efficient architecture for $2^n$-point DCT algorithm. The proposed approach makes use of the fact that, in most DCT applications, the scaling operation in the DCT unit can be eliminated and combined with the scaling operation in the quantizer unit. This important property is efficiently exploited with the CORDIC(COordinate Rotation DIgital Computer) algorithm to produce a regular architecture suitable for VLSI implementation. Although there have been several attempts to exploit CORDIC algorithm in developing DCT architectures, the proposed approach provides the most efficient way for scaled DCT applications by completely eliminating the scale factor compensation.

• Journal of Korea Multimedia Society
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• v.14 no.10
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• pp.1238-1242
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• 2011

An efficient architecture for the reduction of complexity in forward quantization of H.264/AVC is presented in this paper. Since the multiplication operation in forward quantization plays crucial role in complexity of algorithm. More efficient quantization architecture with simplified high speed multiplier is proposed. It uses the modification of the quantization operation and the high speed multiplier is applied for simplification of quantization process.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.516-520
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• 2009

RSA crypto-processors equipped with more than 1024 bits of key space handle the entire key stream in units of blocks. The RSA processor which will be the target design in this paper defines the length of the basic word as 128 bits, and uses an 256-bits register as the accumulator. For efficient execution of 128-bit multiplication, 32b*32b multiplier was designed and adopted and the results are stored in 8 separate 128-bit registers according to the status flag. In this paper, an efficient method to execute 128-bit MAC (multiplication and accumulation) operation is proposed. The suggested method pre-analyzed the all possible cases so that the MAC unit can remove unnecessary calculations to speed up the execution. The proposed architecture prototype of the MAC unit was automatically synthesized, and successfully operated at 20MHz, which will be the operation frequency in the RSA processor.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.11-13
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• 2007

There has been much interest in stream query processing. Various index techniques and advanced join techniques have been proposed to efficiently process data stream queries. Previous proposals support rapid and advanced response to the data stream queries. However, the amount of data stream is increasing and the data stream query processing needs more speedup than before. In this paper, we proposed novel query processing techniques for large number of incoming documents stream. We proposed Dissection Technique for efficient query processing in the data stream environment. We focused on the dissection technique in join query processing. Our technique shows efficient operation performance comparing with the other proposal in the data stream. Proposed technique is applied to the sensor network system and XML database.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.503-508
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• 2002

According to passengers gain and headway's contraction, railway vehicle is required quick and correct running. The importance of ATC device was increased gradually, and also is acting important role in safe train running and efficient use in this reason. Now, railway vehicle that is manufactured or is remodeled are designed to most automatic driving system, and ATC device design direction than other device of railway vehicle influences to whole system in this reason. Also, according as system becomes complicated gradually, importance of fault tracing function fur ATC device is emphasized gradually, and in this reason research about efficient fault tracing method is to act important role heightening reliability of ATC device. In this document, that analyzing about result through examination of automatic train operation system of localization model ATC device(SG-100) and application example, and do so that investigate about efficient fault Bracing.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.12
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• pp.979-986
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• 2003

The performance characteristics of heating and cooling operation for a heat pump system using seawater heat source and exhaust energy are presented. The heat pump system is made of a waste heat recovery system and a vapor compression refrigeration system. The working fluid is R-22. The heat pump system COPs are measured during heating and cooling operation modes, and the resultant COPs were 9.7 and 7.9, respectively, which are three times higher than those of the heat pump itself. Therefore, the performance of the heat pump system using exhaust energy is excellent compared to that of a general heat pump. The experimental data can be effectively used for the design of the high efficient heat pump using a seawater heat source.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.3
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• pp.121-127
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• 2012

An integrated crypto engine for encryption and decryption of AES algorithm based on unified data-path architecture is efficiently designed and implemented in this paper. In order to unify the design of encryption and decryption, internal steps in single round is adjusted so as to operate with columns after row operation is completed and efficient method for a buffer is developed to simplify the Shift Rows operation. Also, only one S-box is used for both key expansion and crypto operation and Key-Box saving expended key is introduced provide the key required in encryption and decryption. The functional simulation based on ModelSim simulator shows that 164 clocks are required to process the data of 128bits in the proposed engine. In addition, the proposed engine is implemented with 6,801 gates by using Xilinx Synthesizer. This demonstrate that 40% gates savings is achieved in the proposed engine, compared to individual designs of encryption and decryption engine.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.805-812
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• 1989

An efficient diagnostic approach for real-time operation aiding expert system in chemical process plants is discussed. The approach is based on the hybrid of the simplified symptom tree(SST) and the fault consequence digraph(FCD), representation of propagation patterns of fault states. The SST generates fault hypothesis efficiently and the FCD resolve the real fault accurately. Frame based knowledge representation and object-oriented programming make diagnostic system general and efficient. Truth maintenance system enables robust pattern matching and provides enhanced explain facilities. A prototype expert system for supports operation of naphtha furnaces process, called OASYS, has been built and tested to demonstrate this methodology. Utilization of diversified process symbolic data, produced using dynamic normal standards, overcomes the problem of qualitative Boolean reasoning and enhance the applicability.