• International journal of advanced smart convergence
• /
• 제11권2호
• /
• pp.171-184
• /
• 2022

The purpose of this paper is output oriented, in order to maximize the output level of sustainable development efficiency of foreign trade in western China with limited input. This paper adopts the relevant input-output indicators of sustainable foreign trade development of 11 provinces and cities in western China from 2016 to 2020, and uses DEA model to measure their technical efficiency, pure technical efficiency and scale efficiency. Malmquist index was used to calculate the total factor productivity change index of each province in western China from 2016 to 2020. We found that, on the whole, the average values of technical efficiency, pure technical efficiency and scale efficiency of provinces and cities in western China from 2016 to 2020 are greater than 0.8, indicating that the western region has high technical efficiency, relatively high management and institutional level and high existing scale level. Scale efficiency is lower than pure technical efficiency on the whole, indicating that the current sustainable development efficiency of foreign trade in western China is mainly limited by its scale level. The technological progress index is higher than the technological efficiency change index, indicating that the total factor productivity of the sustainable development of foreign trade in western China is mainly driven by technological progress and more influenced by external factors. We think the conclusion of this study can provide important reference information for the sustainable development of foreign trade of provinces and cities in western China.

• 수산해양교육연구
• /
• 제11권1호
• /
• pp.1-23
• /
• 1999

The fisheries control system being now enforced in all countries may be generally classified as three types - the input control system, the output control system, and the technical control system. In Asian countries that have relatively small fishery scales, diverse object species and the fisheries resources has been regarded as "governmental possessions", fisheries have been controled subsidiarily using the technical control system based on the input control system traditionally. While in Europe and America that have relatively large fisheries scales, simple object species and the fisheries resources has been regarded as "common property", fisheries have been controled subsidiarily using the input control system and the technical control system based on the output control system. In Korea, fisheries have been controled subsidiarily using the technical control system based on the input control system traditionally, nevertheless overexplotation and overcapitalization have not been solved. Recently the EEZ was promulgated, the total allowable catch system was introduced to control the EEZ. But the output control system is totally different from the input control system of the Korea traditional fisheries system, simultaneous availableness of both system is considerably difficulty. Therefore a study on new systems to make both systems harmonized has to be performed. The thesis is aimed at presenting the general improvement direction of the Korea fisheries control system as the basis for establishment of the new fisheries control system.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2016년도 추계학술대회
• /
• pp.128-130
• /
• 2016

온라인 콘텐츠와 모바일 단말기의 대중화에 따라 국내 디지털 콘텐츠 산업은 높은 성장률을 보이면서 빠르게 발전하고 있다. 본 연구에서는 DEA 모형을 이용하여 온라인 디지털 콘텐츠 산업의 기술적 효율성을 측정하고 효율성 제고를 위한 시사점을 모색한다. 실증분석을 위한 투입요소로는 업종별 사업체수와 종사자수를 사용하였고, 산출요소로는 총매출액을 사용하였다. 실증분석 결과, 온라인 디지털 콘텐츠 산업의 기술적 효율성은 상당히 낮은 수준인 것으로 나타났으며 이는 주로 규모의 비효율성에 기인한 것으로 분석되었다. 이와 같은 결과는 기술혁신역량을 강화하기 위한 산업성장전략 추진이 필요함을 시사하는 것으로 향후 온라인 디지털 콘텐츠 산업의 경쟁력 제고에 도움이 되는 실질적인 참고자료로 활용될 것으로 기대된다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.218-221
• /
• 2006

In this paper, a high-voltage generator with several mA draw output currents using LTPS-TFT technology is proposed. The new generator can be efficiently boosted about +18V output voltages with 5mA draw output currents and power efficiency ${\eta}$ is around 84% under the conditions of +5V power-supply voltage and 250kHz frequency.

• ETRI Journal
• /
• 제41권2호
• /
• pp.145-159
• /
• 2019

To reduce the number of radio frequency (RF) chains in multiple input multiple output (MIMO) systems, generalized spatial modulation (GSM) techniques have been proposed in the literature. In this paper, we propose a zero-forcing (ZF)-based detector, which performs an initial pruning of the search tree that will be considered as the initial condition in a sphere decoding (SD) algorithm. The proposed method significantly reduces the computational complexity of GSM systems while achieving a near maximum likelihood (ML) performance. We analyze the performance of the proposed method and provide an analytic performance difference between the proposed method and the ML detector. Simulation results show that the performance of the proposed method is very close to that of the ML detector, while achieving a significant computational complexity reduction in comparison with the conventional SD method, in terms of the number of visited nodes. We also present some simulations to assess the accuracy of our theoretical results.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
• /
• pp.91-94
• /
• 2000

This paper is focussed on an optimal efficiency control which is operated by voltage-current pattern such as to maintain the maximum efficiency output characteristics of the motor. The voltage control is realized by phase control thyristers.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 B
• /
• pp.1005-1008
• /
• 1992

This paper deals with a method to Improve the input current waveform in a single phase Rectifier. This method is based on the sophisiticated utilization of the auxiliary circuit consisting of two SCRs and a interphase reacter and the condenser necessary for reducing the fluctuating voltage in output side. The basic theories of the proposed system is treated, and its validity is verified with simulation.

• 한국산학기술학회:학술대회논문집
• /
• 한국산학기술학회 2004년도 추계학술대회
• /
• pp.134-136
• /
• 2004

여러 종류의 제어기중에서 PLC(Programmable Logic Controller)가 가장 많이 사용된다. 그러나 PLC는 PLC의 기종에 따라서 입력 및 출력의 점수가 한정되어 있어 입력 또는 출력을 확장하고자 할 때는 유닛을 추가해야 한다. 이러한 단점을 극복하고자 출력점수의 확장 개수가 적을 경우에는 디코딩에 의한 방법을 사용하면 효율적으로 출력을 활용할 수 있을 것이다. 본 논문에서는 출력 유닛을 위한 디코딩 방법을 제안하고 이의 타당성을 확인한다.

• Transactions on Control, Automation and Systems Engineering
• /
• 제1권1호
• /
• pp.44-49
• /
• 1999

This paper presents a new T-S(Tae-Sugeno) fuzzy controller design method satisfying the output energy bound. Maximum output energy via a quadratic Lyapunov function to obtain the bound on output energy is derived. LMI(Linear Matrix Inequality) problems which satisfy an output energy bound for both of the continuous-time and discrete-time T-S fuzzy control system are also derived. Solving these LMIs simultaneously, we find a common symmetric positive definite matrix P which guarantees the global asymptotic stability of the system and stable feedback gains K's satisfying the output energy bound. A simple example demonstrates validity of the proposed design method.

• 한국정밀공학회지
• /
• 제29권6호
• /
• pp.693-701
• /
• 2012

In this study, a small wind turbine airfoil specialized for national wind condition was designed in order to develop the furling control type HAWT. And then a flow analysis was carried out based on the blade drawing which was designed to characterize of the developed airfoil. The result of the flow analysis showed that the torque on the 3 blades was 180.23N.m. This is equivalent to an output power of 5.66kw and an output efficiency of 0.44. Then we produced and constructed a 3kW - furling control type HAWT by getting the system unit design technology such as the specialized furling control device. By operating this turbine, we could get 3kW of the rated power at a wind speed of 10.5m/s through the ability test. Cut-in wind speed was 2m/s, generator efficiency was 92% at the rated power output. Sound power level was 87.2dB(A). Also we observed that the output power was limited to 10.5m/s with furling system operation.