• 한국컴퓨터정보학회논문지
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• 제23권10호
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• pp.111-117
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• 2018

CHAM is a lightweight block cipher, proposed in ICISC 2017. CHAM-n/k has the n-bit block and the k-bit key, and designers recommend CHAM-64/128, CHAM-128/128, and CHAM-128/256. In this paper, we study how to make optimal software implementation of CHAM such that it has high encryption speed on CPUs with high computing power. The best performances of our CHAM implementations are 1.6 cycles/byte for CHAM-64/128, 2.3 cycles/byte for CHAM-128/128, and 3.8 cycles/byte for CHAM-128/256. The comparison with existing software implementation results for well-known block ciphers shows that our results are competitive.

• 전자공학회논문지C
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• 제34C권12호
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• pp.61-69
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• 1997

This paper proposes a new method for improving the performances of the neural network for optimization using a hyubrid of gradient descent method and dynamic tunneling system. The update rule of gradient descent method, which has the fast convergence characteristic, is applied for high-speed optimization. The update rule of dynamic tunneling system, which is the deterministic method with a tunneling phenomenon, is applied for global optimization. Having converged to the for escaping the local minima by applying the dynamic tunneling system. The proposed method has been applied to the travelling salesman problems and the optimal task partition problems to evaluate to that of hopfield model using the update rule of gradient descent method.

• 음성과학
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• 제14권2호
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• pp.105-114
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• 2007

The performance of speaker identifier is severely degraded in noisy environments. A study suggested the concept of observation membership for enhancing performances of speaker identifier with noisy speech [1]. The method scaled observation probabilities of input speech by observation identification values decided by SNR. In the paper [1], the authors suggested heuristic parameter values for membership function. In this paper we attempt to apply particle swarm optimization (PSO) for obtaining the optimal parameters for speaker identification in noisy environments. With the speaker identification experiments using the ETRI database we prove that the optimization approach can yield better performance than using only the original membership function.

• 한국CDE학회논문집
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• 제11권5호
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• pp.351-358
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• 2006

Recently, the development of new structural model in fixed partial denture system is required to be started from the conceptual design with low cost, high performance and quality. In this point, a FEM based design of partial denture is used to investigate stress distribution on the durable shape. In this paper, the structural performances of partial dentures were analyzed under three biting forces. The periodontal embedding model is introduced on behalf of the detailed supporting tissue, which is composed of dentin, cortical bone, cancellous bone and periodontal ligament. Using topology optimization, the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture was designed.

• International Journal of Fluid Machinery and Systems
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• 제9권4호
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• pp.362-369
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• 2016

The shock-free inflow criterion applied in the development of two-dimensional cascade for turbomachinery design. The developed cascade analysis with potential flow calculation through a panel method has been used to determine the shock-free inflow condition. The combination between cascade analysis and PSO (particle swarm optimization) algorithm provides an opportunity to develop a diagram of a two-dimensional parameter cascade at various airfoil shapes. Analytical equations have been derived from the diagram that will facilitate the turbomachinery designer in applying the shock-free inflow criterion on their developed cascade. This method has been used to develop the very low head axial hydraulic turbine and provides excellent results of numerical and actual prototype performances.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.36-43
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• 2003

This paper presents an optimal tuning method for Fuzzy Logic Controller (FLC) of current controller for HVDC using Genetic Algorithm(GA). GA is probabilistic search method based on genetics and evolution theory. The scaling factors of FLC are tuned by using real-time GA. The proposed tuning method is applied to the scaled-down HVDC simulator at Korea Electrotechnology Research Institute(KERI). Experimental result shows that disturbances are well-damped and the dynamic performances of FLC have the better responses than those of PI controller for small and large disturbances such as ULTC tap change, reference DC current change and DC ground fault.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.110-116
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• 2005

In this paper, a low-complexity ML decoder based on QR decomposition, called LCMLDec decoder, is proposed for the V-BLAST with 2 transmit antennas. Then, it is combined with other suboptimal interference nulling and cancelling decoders originated form QR decomposition such as sorted QR or MMSE-SQRD decoder to generate efficient decoders that significantly improve the performance of the V_BLAST with more than 2 transmit antennas, at the expense of a small increase in complexity. Simulation results are provided to demonstrate the performances and complexities of the proposed decoders.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2001년도 학술논문발표회
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• pp.40-45
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• 2001

The purposes of this study were mix design and quality control of high strength concrete for the construction of high rise complex structure. Desired performances of this high strength concrete were slump flow 50$\pm$10cm, air content 4.5$\pm$1.5% and design strength 400kgf/$cm^2$. Experimental flow was that optimal mix design was selected in the indoor experiment and after that, producing test was done in the batcher plant. Excel lent results of experiment was obtained from binder content 475kg/$m^2$ with replacement ratio 10% of fly ash. The results of field application of high strength concrete was sufficiently satisfied both flowability and compressive strength.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.276-284
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• 1998

Optimum design of bumper beam is investigated using nonlinear CAE structural analysis techniques.In order to minimize its weight, while enhancing structural performances, bumper beam structural analyses were carried out to produce optimum section. Model is composed of bumper beam and stay. First, considering FMVSS safety standard, static strength and energy absorbing capability were estimated for several competitive bumpers through pendulum static analysis, and most promising section was chosen. Next, to ensure dynamic crashworthinesss performance for center pole impact was evaluated for the bumper beam with chosen section through pendulum static analysis, referring to DHS bumper dynamic impact standard. Finally, 2.5 mph bumper beam was designed and its structural performance was estimated. Through this investigation, an optimized bumper beam section with less weight of 20% while maintaining almost equal carshworthiness, compared with a conventional bumper beam section which proved its impact crashworthiness by experiments, was developed.

• 한국농공학회지
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• 제36권3호
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• pp.47-59
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• 1994

The irrigation reservoir operation models developed were tested with weather and field data, and the sensitivity of the water requirement deficiency indices(WRDI) were checked with different initial reservoir storages, irrigated areas, and other water uses from the reservoir storage. Seven reservoir release rules were applied to Yongseol Reservoir. Twenty year WRDIs were computed to check performances of those reservoir release rules. Mean WRDIs were 138, 198, 198, 200, 240, 344, and 1033mm for ROM, TOS, COS, CRR, MSC, FAS, and SRC, respectively. The results indicated that ROM contributes consistently to higher operation efficiencies of an irrigation reservoir. The test results of LFROM and SFROM showed that reservoir operation with the proposed optimization technique ROM would be better suited for an irrigation district than those with the other rules. And the proposed model could be used as a tool to improve reservoir operations.