• Title/Summary/Keyword: STEPwise

Search Result 3,556, Processing Time 0.032 seconds

Improved sintering process of counter electrode for dye-sensitized solar cells

  • Lee, Su Young;Kim, Sang Ho
    • 한국표면공학회:학술대회논문집
    • /
    • 한국표면공학회 2012년도 춘계학술발표회 논문집
    • /
    • pp.227-228
    • /
    • 2012
  • In interfaces between carbon black or Pt and FTO glass in dye-sensitized solar cell counter electrodes, a marginal resistant channel for electrons, we tried to improve the connection by modifying the sintering process. A stepwise sintering process for carbon black and Pt counter electrodes was applied and its effect on power conversion efficiency was studied. Power conversion efficiencies of built-in DSSC made by a one-step sintering process with carbon black and Pt counter electrodes were about 5.01% and 5.02%, respectively. Cells made with the stepwise sintering process were 5.96% and 6.21%, respectively, indicating an 20% improvement. Fill factor (FF) increased, and it was them main reason for the power conversion efficiency improvement. Step wise sintering increased the adhesion of the interface and reduced the film thickness and surface roughness. As a result, the resistivity of the counter electrode and EIS impedance of DSSCs decreased.

  • PDF

단계적 절차를 이용한 산업기술연구단지 최적입지 결정 - 울산산업기술연구단지를 중심으로 - (Site Selection of Ulsan Industrial Technology Research Park Using Stepwise Procedures)

  • 김복만;최성운
    • 산업경영시스템학회지
    • /
    • 제22권49호
    • /
    • pp.99-113
    • /
    • 1999
  • This paper describes a study which was undertaken in Ulsan City. It attempted to develop stepwise procedures that would aid Ulsan City in making decision of primary importance: what is the optimal site location for establishing a new Industrial Technology Research Park for public development\ulcorner The presented modeling procedures are an adaption of a number of exiting methods for the evaluation of industrial site potential. The procedures to determine the best site location can be divided into three phases : (i)defining the information necessary to compare potential sites, (ii) collecting the information for each site and (iii)evaluation potential sites utilizing the location model.

  • PDF

철도차량 현수장치의 탈선에 대한 민감도 연구 (The Sensitivity Analysis of Derailment in Suspension Elements of Rail Vehicle)

  • 심태웅;박찬경;김기환
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 1999년도 추계학술대회 논문집
    • /
    • pp.566-573
    • /
    • 1999
  • This paper is the result of sensitivity analysis of derailment with respect to the selected suspension elements for the rail vehicle. Derailment phenominon has been explained by the derailment quotient. Thus, the sensitivity of derailment is suggested by a response surface model(RSM) which is a functional relationship between derailment quotient and characteristics of suspension elements. To summarize generation of RSM, we can introduce the procedure of sensitivity analysis as follows. First, to form a RSM, a experiment is performed by a dynamic analysis code, VAMPIRE according to a kind of the design of experiments(DOE). Second, RSM is constructed to a 1$\^$st/ order polynomial and then main effect fators are screened through the stepwise regression. Finally, we can see the sensitivity level through the RSM which only consists of the main effect factors and is expressed by the liner, interaction and quadratic effect terms.

  • PDF

치과대학병원 수익성에 영향을 미치는 요인 분석 (Identifying Factors Affecting Dental University Hospitals' Profitability)

  • 이지훈;김성식
    • 한국병원경영학회지
    • /
    • 제26권2호
    • /
    • pp.17-26
    • /
    • 2021
  • Purposes: This study aims to identify factors affecting dental university hospitals' profitability and understand recent their business condition. Methodology: Data from 2016 to 2019 was collected from financial statement, public open data in 8 dental university hospitals. For the study, multiple regression test with stepwise selection was applied. Findings: First of all, 9 out of 19 independent variables were selected by stepwise selection. As a result of multiple regression test with selected independent variables and the dependent variable(operating profit margin ratio), the factors affecting hospitals' profitability were the number of dental unit chair, hospital location, debt ratio, total capital turnover ratio, employment cost rate, material cost rate, management expense rate, the number of patient per a dentist. Practical Implication: To improve dental university hospitals' profitability, hospitals specifically analysis and manage their cost such as employment, material and management cost and seek effectiveness by managing the proper number of patient per a dentist.

퍼지의 사다리꼴 타입과 영상 단계적 분할을 이용한 동적 적응적 이진화 방법 (Dynamic Adaptive Binarization Method Using Fuzzy Trapezoidal Type and Image Stepwise Segmentation)

  • 이호창
    • 한국멀티미디어학회논문지
    • /
    • 제25권5호
    • /
    • pp.670-675
    • /
    • 2022
  • This study proposes an improved binarization method to improve image recognition rate. The research goal is to minimize the information loss that occurs during the binarization process, and to transform the object of the original image that cannot be determined through the transformation process into an image that can be judged. The proposed method uses a stepwise segmentation method of an image and divides blocks using prime numbers. Also, within one block, a trapezoidal type of fuzzy is applied. The fuzzy trapezoid is binarized by dividing the brightness histogram area into three parts according to the degree of membership. As a result of the experiment, information loss was minimized in general images. In addition, it was found that the converted binarized image expressed the object better than the original image in the special image in which the brightness region was tilted to one side.

단계적 최적화 기법을 통한 관광지역 내 궤도교통수단의 요금결정 연구 (A Study on Determining Fares for Rail Transit in Tour Regions Using a Stepwise Optimization)

  • 양재호;김응철;최은진
    • 대한교통학회지
    • /
    • 제31권6호
    • /
    • pp.12-21
    • /
    • 2013
  • 관광지역 내 궤도교통수단 요금은 사업 타당성 판단의 중요한 변수가 되는 요소이다. 기존 운영자 위주의 요금 결정에서 벗어나, 이용자 측면까지 동시에 고려된 요금을 산출함으로써 운영자와 이용자를 동시에 만족시키는데 본 연구의 목적이 있다. 본 연구의 대상은 인천광역시 중구 월미도 일대를 순환하는 월미은하레일이다. 본 연구에서는 요금의 적정 범위를 판단하기 위해 운영자 비용과 이용자 비용을 최적화하는 모형을 구축하였다. 최적화된 모형을 활용하여 각 변수의 값을 산출한 결과, 정류장 간격은 0.532km, 운행 간격은 0.206시, 정류장 수는 12개소, 운행 대수는 3대로 도출되었다. 이렇게 도출된 변수들을 활용하여 이용자가 지불해야하는 최소요금과 운영자가 징수해야 하는 최소요금을 산출하고, 이를 근거로 요금의 적정범위를 분석한 결과 최소 1,261원에서 최대 5,063원인 것으로 분석되었다. 관광교통수단의 경우 정류장 자체가 관광지 내에 위치하므로 모형 적용시 접근거리 감소폭이 매우 적어 접근비용의 변화폭이 미미하다는 점을 확인할 수 있었다.