• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.73-76
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• 2003

This paper proposes a maximum output power control of grid-connected wind power generation system using cage-type induction generators. For generator control, indirect vector control is used, where d-axis current controls the excitation level and q-axis current controls the generator speed. The generated power flows into the utility through the grid-side converter, by which the do link voltage is controlled to be constant and the ac current is controlled in sinusoid and. The generator speed is adjusted according to wind speed for extracting maximum power generation. Experimental results are shown to verify the validity of the proposed scheme.

• 가정과삶의질연구
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• 제21권3호
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• pp.87-99
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• 2003

The purpose of this study was to examine how the life styles of Korean people are influenced by the value systems of different generations. We analyzed the survey data of the 869 Korean participants aged from 20 to 69. The following results were obtained. First, differences exist among generations in various values such as collectivism, authoritarianism, environmental control, individualism , universalism, egalitarianism, and environmental accommodation. Especially, the older generation shows high scores in collectivism, authoritarianism and environmental accommodation, among traditional values. On the other hand, younger generation scored a higher level in individualism and egalitarianism. Second, there is a generation gap in the life style, as shown in family activities, household work, consumption activities, and leisure activities. In family activities, leisure activities and consumption activities, the younger generations gained higher scores than the older generations. Third, Korean people's value systems affect their life styles. Also, it was found that the interaction between the genera(ion and the value systems affects the life styles of Korean people.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.661-663
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• 2003

Electric generation cost in district Heating CHP system has close relationship with the level of heating price. So far, the calculation of CHP generation cost has been based on cost recovery system in which revenue requirement deducted the revenue from heating-sales. The restructuring of electricity industry determines the market-clearing price every hour and made it impossible that the loss due to the above market cost can be attributed to the generation cost. Hence, the loss is compensated by energy subsidy program in public benefit charge. This analysis derives an efficient action plan for future subsidy program.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권6호
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• pp.230-235
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• 2003

In this paper, a superposed discharge type ozonizer with an internal dielectric that can be made into a vacuum tube has been designed and fabricated. Ozone generation and discharge characteristics have been investigated in accordance with output voltage of power supply, flow-rate, discharge power and vacuum of inside internal dielectric. Pure oxygen was used as the supply gas of the ozonizer. Ozone concentration and ozone generation are gradually increased when discharge power is increased at the same flow-rate and they are both proportional to the vacuum level. As such, the maximum ozone concentration of 8840 ppm was obtained at vacuum 0.1 Torr and flow-rate 0.5 $\ell$/min.

• 대한전기학회논문지
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• 제43권3호
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• pp.504-514
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• 1994

Combinational automatic test pattern generators (CATPG) have already been commercialized because their algorithms are well known and practical, while sequential automatic test pattern generators(SATPG) have been regarded as impractical because they are computationally complex. A technique to use CATPG instead of SATPG for test generation of sequential circuits is proposed. Redesign of seauential circuits such as Level Sensitive Scan Design (LSSD) is inevitable to use CATPG. Various partial scan techniques has been proposed to avoid full scan such as LSSD. It ha sbeen reported that SATPG is required to use partial scan techniques. We propose a technique to use CATPG for a new partial scan technique, and propose a new CATPG algorithm for the partially scanned circuits. The partial scan technique can be another choice of design for testability because it is computationally advantageous.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.40-47
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• 2000

One of the drawbacks of GA-based structural optimization is that the fitness evaluation of a population of hundreds of individuals requiring hundreds of structural analyses at each CA generation is computational too expensive. Therefore, a parallel genetic algorithm is developed for structural optimization on a cluster of personal computers in this paper. Based on the parallel genetic algorithm, a population at every generation is partitioned into a number of sub-populations equal to the number of slave computers. Parallelism is exploited at sub-population level by allocationg each sub-population to a slave computer. Thus, fitness of a population at each generation can be concurrently evaluated on a cluster of personal computers. For implementation of the algorithm a virtual distributed computing system in a collection of personal computers connected via a 100 Mb/s Ethernet LAN. The algorithm is applied to the minimum weight design of a steel structure. The results show that the computational time requied for serial GA-based structural optimization process is drastically reduced.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.19-25
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• 2013

Energy generation from an instrumented Skystream 3.7 small wind turbine was used to investigate the effect of ambient turbulence levels on wind turbine power output performance. It is widely known that elevated ambient turbulence level results in decreased energy production, especially for large sized wind turbine. However, over the entire wind speed range from cut in to the rated wind speed, the measured energy generation increased as ambient turbulence levels elevated. The impact degree of turbulence levels on power generation was reduced as measured wind speed approached to the rated wind speed of 13m/s.

• Journal of Communications and Networks
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• 제7권1호
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• pp.54-64
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• 2005

This paper presents an advanced architecture for a traffic generator capable of producing ATM traffic streams according to fully general semi-Markovian stochastic models. The architecture employs a basic traffic generator platform and enhances it by adding facilities for 'driving' the cell generation process through high-level specifications. Several kinds of optimization are employed for enhancing the software's speed to match the hardware's potential and for ensuring that traffic streams corresponding to models with a wide range of parameters can be generated efficiently and reliably. The proposed traffic generation procedure is highly modular. Thus, although this paper deals with ATM traffic, the main elements of the architecture can be used equally well for generating traffic loads on other networking technologies, IP-based networks being a notable example.

• 전력전자학회논문지
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• 제24권2호
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• pp.105-110
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• 2019

This study proposed a reactive power variation (RPV) method equipped with positive feedback (PF) for detecting the islanding operation of distributed generation systems. The proposed RPV consists of the constant reactive power component and a certain reactive power term and uses the frequency deviation between the rated and the measured frequencies. The constant reactive power is injected from distributed generation system and power factor is to 0.9975 in grid-connected operation. PF is activated from generation of the frequency deviation and the injected reactive power is continuously increased due to PF when islanding occurs. Consequently, the increasing reactive power causes the point of common coupling frequency to deviate from the maximum/minimum threshold level. Performance of the proposed RPV is verified in a 1.7 kW T-type inverter, and the detection times are 53 and 150 ms.

• ETRI Journal
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• 제46권1호
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• pp.106-117
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• 2024

Large language models (LLMs) have revolutionized various applications in natural language processing and exhibited proficiency in generating programming code. We propose a framework for evaluating the code generation ability of LLMs and introduce a new metric, pass-ratio@n, which captures the granularity of accuracy according to the pass rate of test cases. The framework is intended to be fully automatic to handle the repetitive work involved in generating prompts, conducting inferences, and executing the generated codes. A preliminary evaluation focusing on the prompt detail, problem publication date, and difficulty level demonstrates the successful integration of our framework with the LeetCode coding platform and highlights the applicability of the pass-ratio@n metric.