• 가정과삶의질연구
• /
• 제16권4호
• /
• pp.69-82
• /
• 1998

As a way to serve housing information providing on internet will be a useful method in the near future in Korea. This study was planned to review the housing information on internet network which provided by U. S. .University CES(cooperative extension service) Comparative analysis was used as a Research method in terms of contents and items about housing information on internet provided by U. S. university CES during two weeks each in August 1997 and July 1998. Findings are as follows; Universities providing housing information and information items had been remarkably increased during one year since August 1997. Most of housing informations except one university CES were free to use in 1997 but three university CES among 12 universities showed only the title of items with charge amounts in 1998. Informations about 'Housing Management' and 'Environment' items were the large parts of the housing information in 1997. In 1998. 'Environment' items were remarkably increased. Items bout insects and mildew removing were large portion of the 'Housing Management'. Items about energy saving water and air quality were large portion of the 'Environment' These findings will be useful to develop items of housing information on internet network with Korean language which should be compensated by the survey research.

• Journal of Electrical Engineering and Technology
• /
• 제5권4호
• /
• pp.552-560
• /
• 2010

This paper presents an application of layered Artificial Neural Network controller to study load frequency control problem in power system. The objective of control scheme guarantees that steady state error of frequencies and inadvertent interchange of tie-lines are maintained in a given tolerance limitation. The proposed controller has been designed for a two-area interconnected power system. Only one artificial neural network controller (ANN), which controls the inputs of each area in the power system together, is considered. In this study, back propagation-through time algorithm is used as neural network learning rule. The performance of the power system is simulated by using conventional integral controller and ANN controller, separately. For the first time comparative study has been carried out between SMES and CES unit, all of the areas are included with SMES and CES unit separately. By comparing the results for both cases, the performance of ANN controller with CES unit is found to be better than conventional controllers with SMES, CES and ANN with SMES.

• Journal of Electrical Engineering and Technology
• /
• 제5권4호
• /
• pp.530-537
• /
• 2010

By development of renewable energy and more efficient facilities in an increasingly deregulated electricity market, the operation cost of distributed generation (DG) is becoming more competitive. International environmental regulations of the leaking carbon become effective to reinforce global efforts for a low-carbon paradigm. Through increased DG, operators of DG are able to supply electric power to customers who are connected directly to DG as well as loads that are connected to entire network. In this situation, a community energy system (CES) with DGs is a new participant in the energy market. DG's purchase price from the market is different from the DG's sales price to the market due to transmission service charges and other costs. Therefore, CES who owns DGs has to control the produced electric power per hourly period in order to maximize profit. Considering the international environment regulations, CE will be an important element to decide the marginal cost of generators as well as the classified fuel unit cost and unit's efficiency. This paper introduces the optimal operation of CES's DG connected to the distribution network considering CE. The purpose of optimization is to maximize the profit of CES. A Particle Swarm Optimization (PSO) will be used to solve this complicated problem. The optimal operation of DG represented in this paper would guide CES and system operators in determining the decision making criteria.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2011년도 학술발표회
• /
• pp.327-327
• /
• 2011

본 연구에서는 영국 환경청의 지원 하에 HR Wallingford에서 2003년에 개발한 Conveyance Estimation System(CES)을 이용하여 하천 조도계수를 산정해보고자 하였다. CES프로그램은 하천지형 정보인 단면 형상, 하상경사, 하상재료, 식생 상태 등의 정보를 바탕으로 임의 단면내 각 저항요인에 따라 프로그램에서 제시하고 있는 조도계수를 적용함으로써 수위변화에 따른 단면적, 유량, 통수능, 동수반경 등의 계산 결과를 제공한다. 이러한 계산 결과들을 Manning식에 대입함으로 써 유량 변화에 따른 조도계수를 산정할 수 있다. 섬진강 곡성 지점에 CES프로그램을 적용하여 계산된 조도계수를 실측 조도계수, 하천정비기본 계획에 제시된 조도계수와 비교하였다. 산정된 조도계수는 모두 유량 증가에 따라 감소하는 경향을 보이며, 약 $1,000m^3/s$이상의 고유량에서 실측자료를 이용하여 산정된 조도계수와 유사한 값에서 수렴하는 결과를 나타내고 있다. 섬진강 곡성지점 외에 추가 지점을 분석한 결과에서도 실측 조도계수와 CES를 이용한 조도계수가 큰 차이를 보이지 않았다. 따라서 CES프로그램을 이용하면 하천의 지형 정보만을 가지고도 조도계수, 수위-유량 관계식 등의 추정이 가능하기 때문에 실무적으로 유용하게 사용될 것이다.

• 한국수소및신에너지학회논문집
• /
• 제32권6호
• /
• pp.663-668
• /
• 2021

For the development of highly efficient quantum dot-sensitized solar cells (QDSCs), it is important to enhance the electrocatalytic activity of the counter electrodes (CEs). Herein, a fabrication process of Cu₂S CEs are optimized for the development highly efficient QDSCs. The surface of brass film is treated with HCl solution to prepare the Cu₂S CEs, and the concentraion as well as the temperature of HCl solution are controlled. It is found that the uniformity for the thickness of prepared Cu₂S CEs is enhanced when the diluted HCl solution is used, compared to the HCl solution of standard concentration. In addition, the electrocatalytic activity of the Cu₂S CEs is also increased with the modificed process, which is confirmed by impedance data and Tafel polarization curves. As a result, the photoconversion efficiency of QDSCs is improved from 4.49% up to 5.73%, when the concentraion and temperature of the HCl treatment are efficiently optimized.

• 한국수소및신에너지학회논문집
• /
• 제34권6호
• /
• pp.785-791
• /
• 2023

Copper sulfide (Cu_xS) has been extensively utilized as a counter electrode (CE) material for quantum dot solar cells (QDSCs) due to its exceptional catalytic activity for polysulfide electrolytes. The typical fabrication method of Cu₂S CEs based on brass substrate is dangerous, involving the use of a highly concentrated hydrochloric acid solution in a relatively high temperature. In contrast, electroplating presents a safer alternative by employing a less acidic solution at a room temperature. In addition, the electroplating method increases the probability of obtaining CEs of consistent quality compared to the brass method. In this study, the optimized electroplating cycle for CuS CEs in QDSCs has been studied for the highly efficient photovoltaic performances. The QDSCs, featuring electroplated CuS CEs, achieved an impressive efficiency of 7.18%, surpassing the conventional method employing brass CEs, which yielded an efficiency of 6.62%.

• Korean Journal of Mathematics
• /
• 제25권1호
• /
• pp.117-126
• /
• 2017

The subnormality of some classes of operators is a very interesting property. In this paper, we prove that the weighted $Ces{\grave{a}}ro$ operator $C_h{\in}{\ell}^2(h)$ is subnormal and we described completely the set of the extended eigenvalues for the weighted $Ces{\grave{a}}ro$ operator, some other important results are also given.

• Kyungpook Mathematical Journal
• /
• 제45권1호
• /
• pp.73-85
• /
• 2005

In this paper a criterion for $L^1-convergence$ of a new modified sine sums is obtained by using $Ces{\grave{a}}ro$ means of integral and non-integral orders.

• Kyungpook Mathematical Journal
• /
• 제56권2호
• /
• pp.357-366
• /
• 2016

In this paper, deferred statistical convergence is defined by using deferred $Ces{\grave{a}}ro$ mean instead of $Ces{\grave{a}}ro$ mean in the definition of statistical convergence. The obtained method is compared with strong deferred $Ces{\grave{a}}ro$ mean and statistical convergence under some certain assumptions. Also, some inclusion theorems and examples are given.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2008년도 추계학술대회 논문집
• /
• pp.157-159
• /
• 2008

본 논문은 전력의 안정적 공급 및 신뢰도 확보를 위해 전력설비의 실시간 감시 및 예방진단 시스템을 위해 텔레메트릭스 기법을 이용한 원격 통신시스템에 대한 연구를 통한 옥내용 전기안전감시진단시스템 (CES_RTU : Consumer Electrical Safety-Remote Terminal Unit)에 대한 새로운 알고리즘을 설계에 관련된 연구를 하였다.