• 한국태양에너지학회 논문집
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• 제39권2호
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• pp.81-92
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• 2019

When Photovoltaic inverter is connected to grid and used as PVPCS (Photovoltaic Power Conditioning System), 120 Hz AC ripple occurs at the dc-link capacitor voltage. This AC ripple reduces the efficiency of PVPCS and shortens the lifetime of the capacitor. In this paper, we design a notch filter to remove AC ripple. As a result, the AC voltage ripple was removed from the dc link and the THD of the PVPCS output current with the notch filter was lowered. This notch filter is determined by the damping coefficient, the bandwidth coefficient, and the switching frequency. Among these, the switching frequency determines the switching loss and the size of the LC filter, and the PVPCS with the high switching frequency has a greater efficiency loss due to the switching loss than the efficiency improvement by the notch filter. Therefore, it is important to set the optimum switching frequency in the PVPCS with the notch filter applied. In this paper, THD and switching loss of PVPCS output current with notch filter are calculated through simulation, and cost function to calculate optimum switching frequency through data is proposed.

• 한국정보처리학회논문지
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• 제4권1호
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• pp.29-53
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• 1997

기존의 교환기 시스템은 주로 화일 시스템이나 관계형 데이터베이스를 이용하여 교환기 운용에 관련된 데이타를 관리해 오고 있다. 하지만, 통신망이 급속히 발전하 면서 교환기에 다양한 기능이 요구됨에 따라 관계형 데이타베이스 시스템으로는 효과 적인 데이타 관리가 어렵게 되었다. 본 연구는 교환기 시스템을 위한 관계형 데이타 베이스 시스템인 DREAM을 확장하여, 보다 강력한 데이타 모델링 기능을 지원하여 객 체지향 인터페이스를 제공하는 방안을 제시한다. 아울러, 제시하는 기법을 DREAM 시 스템 상에 적용하는 과정을 예시한다.

• 한국컴퓨터정보학회논문지
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• 제11권5호
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• pp.231-239
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• 2006

교환 시스템을 구동하는 대규모 소프트웨어에서는 여러 기능간의 상호 데이터 교환과 그 처리를 위하여 실시간 데이터베이스의 사용이 필수적이다. 교환기용 DBMS 소프트웨어 개발에서는, 데이터베이스 질의어를 포함하는 응용 프로그램을 우선 호스트 컴퓨터상에서 개발하고, 이렇게 개발한 응용 프로그램을 나중에 교환기 본체에 로딩하여 그 기능을 시험한다. 호스트 컴퓨터 상에서 데이터베이스 응용 프로그램을 개발할 수 있도록 하기 위해 연구 개발한 것이 호스트 기반 DBMS 시뮬레이션 시스템(HDBMS) 이다. 본 논문에서는 HDBMS의 역할과 기능, 시스템 구성, 시스템 구현을 위한 기술적인 세부 사항에 대해 우리가 연구한 내용을 소개한다.

• 한국의류학회지
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• 제31권3호
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• pp.440-450
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• 2007

The purpose of this study was intended to investigate influence of consumer's brand loyalty, competitor's brand price and brand switching intention in condition of discount sale of casual apparel products. The data for the study was obtained through the use of an experimental design which was $2{\times}[2{\times}2]$ mixed factorial design. The subjects were 730 college students. The data were analyzed by cluster analysis, ANOVA, simple interaction analysis and simple main-effect analysis. The following results were founded: First, The results indicated that the 3-way interaction effects among consumer's brand loyalty competitor's brand price and discount on brand switching of casual apparel products. Second, the results indicated that the 3-way interaction effects among consumer's brand loyalty competitor's brand price and discount on consumer preference of casual apparel products. These results indicated that low brand loyalty group on casual products showed high preference and high brand switching on competitors brand when competitor's brand price was lower than preferred brand price and discount type was absolute frame. High bran loyalty group on casual apparel products preferred and switched high competitor's brand when discount type was absolute frame.

• Asian Journal of Business Environment
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• 제11권3호
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• pp.5-19
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• 2021

Purpose: The purpose of this research is to study the role of life satisfaction, quality consciousness, and religiosity, which are integrated with the TRA Model to explain the switching intention of Muslim consumers to use Halal Cosmetics and Personal Care (HCPC). The second purpose is to investigate the relationship between variables used in this study to provide recommendations to HCPC producers about Muslim consumer behavior in the market. Research design, data, and methodology: The target population in this study is Muslims who live in Greater Jakarta. Data collection is carried out by the self-administered survey method based on the Purposive sampling technique, and the questionnaire is distributed online. The statistical analysis to test the research hypotheses is the Partial Least Squares - Structural Equation Model (PLS-SEM). Results: Life satisfaction, product quality consciousness, and religious commitment have a significant effect on attitude to switching but do not significantly influence the intention of switching to use HCPC. Conclusions: Life satisfaction, quality consciousness, and religiosity that represent individual factors indirectly affect the intention to switch to use HCPC. Thus, religious commitment influences attitude to switching both directly and indirectly.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2005년도 추계학술대회
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• pp.161-169
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• 2005

In this paper we propose a fuzzy c-regression model based on weighted least squares support vector machine(LS-SVM), which can be used to detect outliers in the switching regression model while preserving simultaneous yielding the estimates of outputs together with a fuzzy c-partitions of data. It can be applied to the nonlinear regression which does not have an explicit form of the regression function. We illustrate the new algorithm with examples which indicate how it can be used to detect outliers and fit the mixed data to the nonlinear regression models.

• 대한전자공학회논문지SD
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• 제41권9호
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• pp.57-64
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• 2004

본 논문에서는 비동기식 회로 설계시 2선식(Dual-Rail) 코드를 사용할 때, 회로 구조에서 갖는 신호 천이를 줄여 소비전력을 감소시키는 RZ/NRZ 혼합 데이터 전송 방식을 제안한다. RZ 방식 2선식 코드는 비동기 회로 구현에 많이 사용되고 있으며, 고정 지연을 사용하는 단선구조와는 달리 데이터를 통하여 신호의 유효성을 판별할 수 있다 그러나, 단선 구조에 비해 많은 회로 면적과 모든 신호가 Return-to-Zero의 스위칭에 의해 전력 소비를 가져오므로, 신호 천이의 수를 감소시킬 필요가 있다. 본 논문에서는 RZ/NRZ 방식을 제안하여 스위칭을 약 50% 감소시키며 소비전력을 비교한 결과, 기존의 2선식에 비해 약 23% 정도 감소하는 결과를 얻었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.353-356
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• 2003

As the wireless mobile telecommunication system has been developed with astonishment, its offering service has also widely been expanded including various data service. Currently, the wireless mobile telecommunication network presents voice service that covers for the most part of the whole service areas. For this reason, the availability of the switching capacity in the mobile switching center(MSC) is manipulated by the required volume of voice service. However, considering the increase of data service, it is desirable for the current switching method to be modified for more efficiency. In this Paper, we analyze the data traffic caused by providing data service in the wireless mobile telecommunication network. For this, we are firstly going to review the result of the analysis in the feature of the data traffic. Secondly, based on the review, we are also going to perform analyzing the other feature of the data traffic normally generated in the wireless mobile telecommunication network. We expect that this paper would be utilized as an elementary source for the feature of the SMS data .traffic and it will be an honour for ourselves to work on it.

• 한국위성정보통신학회논문지
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• 제10권4호
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• pp.71-76
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• 2015

본 연구는 LTE, 5G의 무선 통신네트워크망에서 효율적으로 무선에너지하비스팅과 데이터 전송 실시하기 위한 시스템 모델을 제시한다. 수신 된 신호의 파워를 타임 스위칭(Time Switching)과 파워 스플릿팅(Power Splitting) 기법을 통해 우리가 원하는 무선에너지하비스팅 효율과 데이터 전송률을 만족시키기 위한최적의 타암 & 파워 비율을 찾는다. 그래서 최적의 시간 & 파워 비율을 선정함으로써 우리는 효율적으로 데이터 전송과 에너지하비스팅이 가능하다. 또 이상적인 수신기와 제안한 시스템 모델의 비교를 통해 성능 분석을 실시하고, 앞으로의 연구방향을 제시한다.

• 전자공학회논문지
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• 제50권1호
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• pp.97-101
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• 2013

There is a growing need for optical communication systems that convert large volumes of data to optical signals and that accommodate and transmit the signals across long distances. Digital optical communication consists of a master unit (MU) and a slave unit (SU). The MU transmits data to SU using digital optical signals. However, digital optical units that are commercially available or are under development transmit data using two's complement representation. At low input levels, a large number of SSOs (simultaneous switching outputs) are required because of the high rate of bit switching in two's complement, which thereby increases the power noise. This problem reduces the overall system capability because a DSP (digital signal processor) chip (FPGA, CPLD, etc.) cannot be used efficiently and power noise increases. This paper proposes a change from two's complement to a more efficient method that produces less SSO noise and can be applied to existing digital optical units.