• 제어로봇시스템학회논문지
• /
• 제7권11호
• /
• pp.912-917
• /
• 2001

In this study, we define the measuring method of crank angle precisely using an event and perform a study on the hardware structure and software algorithms which is applicable for the commercial engine. Also we developed a Computer-ECU(Personal computer based electronic control unit) using a computer and a microprocessor, for performing the ignition at a desire position(angle) and for controlling a duty ratio a pulse for ISC(Idle speed control). We applied these algorithms to the modeling which is induced a concept of event and got a better result than a conventional ECU in the state of transient as a result of performing air fuel ratio control in a commercial engine. This technique can be used for the back to improve ECU performance. It the present type of Hybrid I. C voltage regulator is altered to the new type of regulator, we will be surely able to reduce the production cost as well as simplify the design of alternator\`s rear bracket and rectifier part because of the removal of trio diode. Experiment is taken by MS-R004.

• 한국전기전자재료학회논문지
• /
• 제23권11호
• /
• pp.901-905
• /
• 2010

PV module has many power loss factors, and series resistance is the most important elements of them. It is therefore easy to expect the partial shading decrease the lifetime of the semiconductor depletion layer in thin film PV module. Different shading losses could be related with the hot spot which is critical in expecting the reliability issue. In this paper we have modelled the series resistance of the PV module with both different direction of the cell line and shading area of the panel. From the results, thin film a-Si PV module has shown different properties by shading direction.

• 한국생활과학회지
• /
• 제16권2호
• /
• pp.443-454
• /
• 2007

Survey questionnaires were conducted on housewives under 60 who had bought an apartment in Daegu. The data used in this study is collected Dalseo-Gu, Soosung-Gu and Buk-Gu by means of cluster sampling and from those chosen samples I use convenience sampling. The data were analyzed by SPSS WIN 10.0 program. The purpose of this study is to examine housing characteristics and apartment choice as a social class closely in order to improve value of apartment and to provide housing plan of apartment supply which is distinguished by a social class and moreover, to achieve efficient marketing strategy according to a recent recognition that housing is a kind of commodities. Objective and subjective measure of value are used to classify a social class. Objective measure of value includes scale apartment, a form of possession, a price of apartment, an occupation of husband, family income and academic background and subjective measure of value includes the standard of living out of people's own head. These measure of value are classified by giving consequence to each item with reference to ISC (index of status characteristics) of Wanner. There is a difference of housing characteristics and apartment choice as a social class as a consequence of this study. Therefore, this study suggests repeatedly that it should need not standardized housing supply but apartment supply of diverse demand desire because there is a difference of housing characteristics and apartment choice as a social class.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
• /
• pp.36-41
• /
• 2008

In this paper, we study The Effects of PV Cell's Electrical Characteristics for PV Module Application. Photovoltaic module consists of serially connected solar cell which has low open circuit voltage and high short circuit current characteristics. The whole current flow of PV module is restricted by lowest current of one solar cell. For the experiment, we make PV module composing the solar cells that have short circuit current difference of 0%, 1%, 3% and Random. The PV module exposed about 35days, its the maximum power drop ratio was 4.282% minimum and 6.657% maximum. And PV module of low current characteristics has electrical stress from other modules. The solar cell temperature of PV module was higher compared to PV cell. To prevent early degradation, it is need to have attention to PV cell selection.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
• /
• pp.252-256
• /
• 2008

Photovoltaic (PV) modules output changes noticeable with variations in temperature and irradiance. In general it is has been shown that a $1^{\circ}C$ increase in temperature results in a 0.5% drop in output. In this paper, seven PV module types are analyzed for variation in temperature and irradiance, and the resulting output characteristics examined. The 7 modules types utilized are as follows; 3 poly crystalline modules, 2 single crystalline modules, 1 back contact single crystalline module and 1 HIT module. 3 groups of experiments are then conducted on the modules; tests with varying irradiance values, tests with module temperature varying under $25^{\circ}C$ and tests with module temperature varying over $25^{\circ}C$. The experiments results show that as temperature rises the follow is observed; Pmax decreases by 0.6%, Voc decreases by about 0.4%, and Isc increasing by between 0.03%${\sim}$0.08%. In addition, an irradiance decrease of 100 w/m2 translates into a 10% drop in Pmax.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
• /
• pp.257-262
• /
• 2008

In this paper, we study the electric characteristics of shading effects in photovoltaic module in case of outdoor operation. When fabricating PV module, solar cells are connected serially to obtain the high voltage because of its low open circuit voltage. And total current is determined by lowest current among solar cells. When the shading happens on PV module's surface, the current of shaded solar cell determine the total current flow. Because of this, generally by-pass diode is installed on junction box. The bypass diode operate when revered and shaded solar cell's voltage is over 0.6 voltage. The reverse-biased solar cell gives reduced maximum power of PV module and might give negative effect on durability. So, adequate by-pass installation and selection is needed.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 하계학술대회 논문집
• /
• pp.64-64
• /
• 2010

This paper presents the results of changes of optical properties of front materials in crystalline PV modules. If PV modules on the outdoor, transmittance of front materials is reduced by solar light. That is UV, IR included Solar spectrum will have change the properties of glass. Therefore decrease in transmittance leads to loss of the PV modules output. All the PV modules showed the loss in Isc by 1~5% within few hors. To investigate the changes we are analyzed using spectrophotometer from raw glass to laminated glass.

• 대한기계학회논문집B
• /
• 제32권11호
• /
• pp.884-890
• /
• 2008

Many researches have been carried out to reduce the emission levels and lower the fuel consumption in SI engines. Recently electronically controlled injection system is widely adapted to a passenger car to achieve these goals. Throttle body is also an important factor which influences on the emissions and engine power. In this study we redesigned a throttle body and conducted an experimental study to see the effects on engine performance and emission characteristics. We could find that idle speed control(ISC) showed stable operation characteristics as the cooling water temperature varied. And CO and HC emissions also satisfied the regulation limit.

• 한국수학사학회지
• /
• 제21권3호
• /
• pp.157-182
• /
• 2008

TIMSS는 수학 과학 성취도 추이변화 국제비교 연구로서 가장 대규모로 여러 국가의 수학 성취도를 파악, 분석하고 있다. 본 연구는 두 가지 연구 내용을 담고 있는데, 첫째는 4주기에 걸친 TIMSS의 인지영역 평가틀의 변화를 살펴봄으로써 평가틀과 문항 개발의 시사점을 얻는 것이다. 둘째는 TIMSS 2007 인지영역 평가틀에 따라 우리나라 학생들의 수학 성취도를 6개국과 비교 분석하는 것이다. TIMSS 2003에서 우리나라는 수학 전체 성취도가 싱가포르와 유의한 차이로 2위를 차지했는데, 수학적 능력을 살펴볼 수 있는 인지영역별로는 알기가 국제 1위, 적용하기가 3위, 추론하기가 2위를 차지하였다. 이를 바탕으로 평가틀 개발 및 다른 나라의 교육 체계나 교육과정으로부터의 시사점 등에 대한 제언을 하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.1100-1101
• /
• 2008

After lamination process, Isc is increased by sheet reflection. This paper presents the electrical output characteristics by back sheet reflection. The experiments was conducted by using single crystalline and multi crystalline PV module. The reflection area of single crystalline PV module is larger than multi one due to the difference of solar cell manufacturing. The experiments show that the increased performance ratio of single crystalline PV module output power is 1.55% rather than that of multi crystalline PV module output power is 1.13%. In addition, it is expected that the output power of single one rather than multi-one is increased by the lower temperature when the PV module is installed outside. The results can be reconsidered by the test material and test process. Back sheet used for humidity prevention makes PV module output power increasing.