• Journal of the Korean Statistical Society
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• 제15권1호
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• pp.31-45
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• 1986

It is often necessary to obtain some run orders in factorial designs which have a small number of factor level changes and a small linear time trend. In this paper we propose an algorithm to find optimal or near-optimal run orders for $2^4, 2^5, 3^2$ and $2\cdot 3^2$ factorial designs under the criterion that the number of factor level changes and the linear time trend should be simultaneously small.

• Wind and Structures
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• 제23권6호
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• pp.577-594
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• 2016

In this paper a practical modelling methodology is presented for a series of aero- servo- elastic- coupled numerical analyses of small wind turbine operation, with particular emphasis on variable speed generator modelling in various wind speed conditions. The following characteristics are determined using the available computer tools: the tip speed ratio as a function of the generator constant (under the assumption of constant wind speed), the turbine coefficient of power as a function of the tip speed ratio (the torque curve is modified accordingly and generator speed and power curves are plotted), turbine power curves and coefficient of power curve as functions of the incoming wind speed. The last stage is to determine forces and torques acting on rotor blades and turbine tower for specific incoming wind speeds in order to examine the impact of the stall phenomena on these values (beyond the rated power of the turbine). It is shown that the obtained results demonstrate a valuable guideline for small wind turbines design process.

• International Journal of Computer Science & Network Security
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• 제21권7호
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• pp.359-364
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• 2021

In recent years Hadoop usage has been increasing day by day. The need of development of the technology and its specified outcomes are eagerly waiting across globe to adopt speedy access of data. Need of computers and its dependency is increasing day by day. Big data is exponentially growing as the entire world is working in online mode. Large amount of data has been produced which is very difficult to handle and process within a short time. In present situation industries are widely using the Hadoop framework to store, process and produce at the specified time with huge amount of data that has been put on the server. Processing of this huge amount of data having small files & its storage optimization is a big problem. HDFS, Sequence files, HAR, NHAR various techniques have been already proposed. In this paper we have discussed about various existing techniques which are developed for accessing and storing small files efficiently. Out of the various techniques we have specifically tried to implement the HDFS- HAR, NHAR techniques.

• 한국컴퓨터정보학회논문지
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• 제3권3호
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• pp.129-137
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• 1998

국민경제에서 중소기업이 차지하고 있는 비중은 계속 증가하고 있는 가운데 중소기업의 경영상의 애로점으로 자금 조달의 문제가 가장 심각한 것으로 지적되고 있다. 본 연구는 중소기업의 경영 문제 가운데 재무구조의 실태를 파악하고 이를 대기업 또는 우리나라산업평균 재무비율과 비교함으로써 중소기업의 재무안정성 비율을 분석한 것이다. 조사 분석 결과 전체적으로 산업별 표준비율에는 그 수준이 미치지 못하고 있으나 산업평균과 비교할 때 그 수준이 양호한 것으로 조사되었으며 산업평균에 비해 안정성과 유동성이 양호한 반면 차입금 의존도가 대단히 낮은 것으로 조사되어 국가 또는 행정 자치적인 측면에서 중소기업 자금 지원 정책이 개발되어야 할 것으로 인식되었다.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.495-502
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• 2021

The study is devoted to substantiation of directions of intensification of development of small innovative enterprise, which has a significant impact on the overall innovation activity of the country and promotes innovative development, transition to more advanced technological systems. The outlined role of small business in innovative development in the direction of intensifying innovation in the economy, improving organization and production, as well as in the form of direct participation in the innovation process, production of science-intensive products, stimulating demand for innovation. A group of factors hindering the development of small innovative entrepreneurship was identified, including: financial aspects of the activity, shortcomings of organizational and communicative nature, underdeveloped technology market, information plan problems, internal production problems of small business, market problems. The directions of intensification of the development of small innovative entrepreneurship are substantiated, namely: financial and credit support of small innovative entrepreneurship; introduction of tax incentives; material and technical support; nationwide intensification of innovation activity; information support; development of innovation infrastructure. The involvement of the outlined directions of intensification of small innovative entrepreneurship will help to obtain a synergistic effect of innovative development of both small innovative business structures and the economy as a whole.

• 전력전자학회논문지
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• 제22권4호
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• pp.369-372
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• 2017

This paper presents a control scheme for three-level NPC inverters using small DC-link capacitors. To reduce the inverter system volume, the film capacitor with small capacitance is a promising candidate for the DC-link. When small capacitors are applied in a three level inverter, however, the AC ripple component increases in the DC-link NPV (neutral point voltage). In addition, the three-phase input grid currents are distorted when the DC-link capacitors are fed by diode rectifier. In this paper, the additional circuit is applied to compensate for small capacitor systems defect, and the offset voltage injection method is presented for the stabilization in NPV. These two proposed processes evidently ensure the quality improvement of the input grid currents and output load currents. The feasibility of the proposed method is verified by experimental results.

• 전력전자학회논문지
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• 제27권3호
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• pp.192-199
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• 2022

In DC distribution systems, a TAB converter employing multiple transformers is one of the most widely used topologies due to its high power density, modularizability, and cost-effectiveness. However, the conventional control technique for a grid-connected mode in the TAB converter cannot maintain its reliability for an islanding mode under a blackout situation. In this paper, the islanding mode control technique is proposed to solve this issue. To verify the relative stability and dynamic characteristics of the control technique, small-signal models of both the grid connected and the islanding mode are derived. Based on the small-signal models, PI controllers are designed to provide suitable power control. The proposed control technique, the accuracy of small-signal models, and the performance of the controllers are verified by simulations and experiments with a 1-kW prototype TAB converter.

• 한국항행학회논문지
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• 제14권5호
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• pp.752-759
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• 2010

이 논문에서는 DDR-SSD 기반의 소프트웨어 RAID에서 작은 쓰기 (Small Write) 요청에 대한 RAID5의 RMW (Read Modify Write) 성능 향상을 위한 차-로깅 (Differential Logging) 기법을 제안한다. 엔터프라이즈 웅용에서 빈번하게 발생하는 작은 쓰기 요청은 RAID5에서 주요한 성능 저하의 요인이다. RAID5 에서는 패리티 블록의 일관성을 유지하기 위해 변경이 발생하면 패리티 블록에 대한 변경을 같이 수행해야 한다. 작은 쓰기가 발생하면 기존 데이터에 대한 변경 뿐 아니라, 패리티 블록을 다시 계산하기 위한 추가 입출력연산 및 패리티 계산이 병행되어야 하며 이를 RMW 연산이라 한다. 기존의 하드 디스크 기반의 소프트웨어 RAID 에서는 이러한 작은 쓰기로 인한 성능저하 문제를 해결하기 위해 다양한 방법을 제안하였다. 이 논문에서는 하드 디스크와 전혀 다른 특성을 보이는 DDR-SSD를 고려하여 RAID5의 작은 쓰기 성능을 향상 시키는 차-로깅 기법 기반의 RAIDS를 제안한다. 제안하는 기법은 시뮬레이션을 통해서 리녹스 기반의 MID와 비교하여 성능의 우수함을 보였다.

• 한국컴퓨터산업학회논문지
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• 제2권12호
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• pp.1549-1556
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• 2001

전사적 품질 관리(TQM)의 원칙 적용이 많은 선두 대기업들에 있어서 굉장한 성공을 가져왔음에도 불구하고, 중소기업들은 전사적 품질 관리(TQM)를 채택한 큰 대기업에 비해 뒤쳐져 왔다. 이는, 대기업과 중소기업사이에 현저한 차이가 존재하기 때문으로, 중소기업의 장점과 약점을 이해하는 것이 필수조건이다. 본 연구에서는 전사적 품질 관리(TQM)의 바탕위에 중소기업에 대한 전사적 품질 관리(TQM)의 원칙 적용을 돕기 위한 의도로, 장점과 약점을 규명하고, 적용 전략을 토론한다.

• 한국컴퓨터산업학회논문지
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• 제2권10호
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• pp.1301-1308
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• 2001

이 논문에서는 기존의 number-theoretic 순환함수와 연계된 word-theoretic 순환함수 및 술어(predicates)들의 Grzegorzyk 클래스를 논한다. 특히 small 클래스 $\xi\sum{n}$($n\leq2$)에서의 특성은 그에 대응하는 number-theoretic small 클래스 $\xi\sum{n}$과는 매우 틀린 특성을 보인다 [2]. 흥미 있는 문제 중의 하나인 $\xi\sum{0}$ 등급에서의 동치문제는 undecidable 임을 증명한다.