• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.1
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• pp.17-24
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• 2014

In this paper, we implement and evaluate the performance of a vector-based rasterization algorithm for 3D graphics by using a SIMD (single instruction multiple data) many-core processor architecture. In addition, we evaluate the impact of a data-per-processing elements (DPE) ratio that is defined as the amount of data directly mapped to each processing element (PE) within many-core in terms of performance, energy efficiency, and area efficiency. For the experiment, we utilize seven different PE configurations by varying the DPE ratio (or the number PEs), which are implemented in the same 130 nm CMOS technology with a 500 MHz clock frequency. Experimental results indicate that the optimal PE configuration is achieved as the DPE ratio is in the range from 16,384 to 256 (or the number of PEs is in the range from 16 and 1,024), which meets the requirements of mobile devices in terms of the optimal performance and efficiency.

• Transactions of Materials Processing
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• v.29 no.5
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• pp.272-281
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• 2020

As the thickness of mobile communication devices is getting thinner, the size of the internal parts is also getting smaller. Among them, the battery case requires a high-level deep drawing technique because it has a rectangular shape with a large aspect ratio. In this study, the initial blank shape was optimized to minimize earing in a multi-stage deep drawing process using an artificial neural network(ANN). There has been no reported case of applying artificial neural network technology to the initial blank optimal design for a square case with large aspect ratio. The training data for ANN were obtained though simulation, and the model reliability was verified by performing comparative study with regression model using random sample test and goodness-of-fit test. Finally, the optimal design of the initial blank shape was performed through the verified ANN model.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.335-336
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• 2014

This paper investigates the design of coupled inductor for minimum inductor current ripple in rapid traction battery charger systems. Based on the general circuit model of coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor which corresponds to a minimum inductor ripple current becomes -1, i.e. a complete inverse coupling without leakage inductance, as the steady-state duty ratio operating point approaches 0.5. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the steady-state duty ratio operating point approaches either zero or one. Coupled inductors having optimal coupling factor can minimize the ripple current of inductor and battery current resulting in a reliable and efficient operation of battery chargers.

• International Journal of Computer Science & Network Security
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• v.21 no.4
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• pp.33-40
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• 2021

The traveling salesman problem (TSP) is one of the well-known and extensively studied NPC problems in combinatorial optimization. To solve it effectively and efficiently, various optimization algorithms have been developed by scientists and researchers. However, most optimization algorithms are designed based on the concept of improving route in the iterative improvement process so that the optimal solution can be finally found. In contrast, there have been relatively few algorithms to find the optimal solution using route construction mechanism. In this paper, we propose a route construction optimization algorithm to solve the symmetric TSP with the help of ratio value. The proposed algorithm starts with a set of sub-routes consisting of three cities, and then each good sub-route is enhanced step by step on both ends until feasible routes are formed. Before each subsequent expansion, a ratio value is adopted such that the good routes are retained. The experiments are conducted on a collection of benchmark symmetric TSP datasets to evaluate the algorithm. The experimental results demonstrate that the proposed algorithm produces the best-known optimal results in some cases, and performs better than some other route construction optimization algorithms in many symmetric TSP datasets.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.455-460
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• 2006

This paper presents the convergency property of the Auxiliary Problem Principle when it is applied to large-scale Optimal Power Flow problems with Distributed or Parallel computation features. The key features and factors affecting the convergence ratio and solution stability of APP are also analyzed.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.1003-1007
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• 2001

This experiment was conducted to investigate the effects of dietary SAA (sulfur-containing amino acids) on growth performance, nutrient digestibility and blood urea nitrogen (BUN) content, and to determine the optimal SAA:lysine ratio for growing barrows and gilts. A total of 150 pigs (75 barrows and 75 gilts, Landrace${\times}$Yorkshire${\times}$Duroc) were assigned to 6 treatments with 5 replicates of 5 pigs per pen. All pigs were fed diets containing either 1.12 (for barrows) or 1.33% (for gilts) dietary lysine with increasing SAA levels (50, 55 and 60% of dietary lysine) in a $2{\times}3$ factorial design. Throughout the whole experimental period (15 to 54 kg body weight), there was no interaction between sexes and SAA:lysine ratios on ADG, ADFI and FCR. However, increasing the SAA:lysine ratio from 50 to 60% in a diet showed a trend to increase ADG and ADFI of barrows. None of differences in nutrient digestibilities except for calcium and phosphorus were observed and gilts showed higher digestibility of calcium and phosphorus (p<0.05). Among dietary SAA:lysine ratios, there were no differences in apparent nutrient digestibility. Mean values of the essential amino acids (EAA), non-essential amino acids (NEAA) and total amino acids (TAA) digestibilities were higher in gilts than barrows (p<0.01). However, no differences in mean value of EAA, NEAA and TAA digestibilities were observed among dietary SAA:lysine ratios. Between sexes and among SAA:lysine ratios, no significant difference in BUN concentration was observed. This study demonstrated that the optimal inclusion ratio of SAA:lysine was 55% and below 50% in barrows and gilts, respectively.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.4
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• pp.156-163
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• 2001

In this paper an optimal switching angle control of a switched reluctance motor (SRM) drive system is investigated for achieving maximum energy conversion ratio. A new magnetizing method is proposed with a low switching frequency. The proposed algorithm maximizes the positive energy conversion region, which is directly related to the mechanical output, and reduces the reactive power region with the same field energy region. As a consequence, a torque ripple is also sufficiently reduced compared with that of the conventional switching angle magnetizing method. Experimental results show that the proposed scheme provides a high efficiency and a low ripple drive.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.251-258
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• 2004

This paper presents the parameter study of multiple tuned liquid damper (MTLCD) applied to the 76-story benchmark building. A parameter study involves the effects of number of TLCD, frequency range, and central tuning frequency ratio, which are important parameters of MTLCD. The performance of MTLCD is carried out numerical analysis which reflects the nonlinear property of liquid motion. The parameters of TLCD exist different each optimal values according to mass ratio. The performance of single-TLCD (STLCD) is sensitive for tuning frequency ratio. Therefore, MTLCD is proposed to protect such the shortcoming of STLCD. The result of numerical analysis presents improved performance for robustness of MTLCD

• Korean Management Science Review
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• v.27 no.1
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• pp.45-60
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• 2010

This study evaluates life annuity plans based on two different types of measures : financial benefit and utility on consumption. The financial benefit is measured by Money's Worth (MW) ratio and return on annuity. For the measure of utility, an optimization problem is formulated with the objective of maximizing utility on consumption. To solve the optimization model, we use Dynamic Programming (DP) technique. The both types of measures are applied to cases of Korean pre-retirees at age 40 with different accumulation years of annuity (i.e. level of annuity asset at the age of retirement) and different timings of annuitization. Our results generally indicate that the utility based optimization model is superior to the financial measures in terms of providing a better evaluation of an annuity plan due to its capability to consider an individual's financial situation during his/her retirement period. Also, they suggest that the level of annuity asset is an important factor when an individual determines the optimal annuitization timing.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.111-119
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• 1997

In this paper, engine-CVT consolidated control performance were investigated experimentally. Engine-CVT consolidated control was composed of engine throttle control based on power difference and CVT ratio control based on CVT ratio map. Experimental results showed that engine optimal operation was obtained while satisfying the driver's desire, i. e., following the given drive mode by engine-CVT consolidated control. Also, it was found that engine performance is subjected to inertia of the powertrain where the magnitude of acceleration changes abruptyly. Comparing with the results of CVT only control, the results of engine-CVT consolidated control showed better performance. Therefore, in order to meet the driver's desire as well as keeping the engine optimal operation, the engine-CVT consolidated control could be suggested as an integral solution.