• 한국기계가공학회지
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• 제10권6호
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• pp.46-49
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• 2011

The grinding is a popular process for studying constant velocity joint and process in automobile industry. In this study, The study gives the data of wheel type and grinding of inner race is developed. As a result I obtained the data of grinding conditions makes good surface roughness get a grinding conditions. The grinding characteristics and conditions of inner race were investigated with respect to grinding feed, cutting depth, grinding time. The results were suddenly increased and the detailed surfaces were extremely obtained. Grinding condition was big more affected by grinding time, grinding speed and grinding depth.

• International Journal of Safety
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• 제1권1호
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• pp.28-35
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• 2002

Kullback Discrimination Information (KDI) is one of the pattern recognition methods. KDI defined as a measure of the mutual dissimilarity computed between two time series was studied for detection and classification of bearing flaking on outer-race and inner-races. To model the damages, the bearings in normal condition, outer-race flaking condition and inner-races flaking condition were provided. The vibration sensor was attached by the bearing housing. This produced the total 25 pieces of data each condition, and we chose the standard data and measure of distance between standard and tested data. It is difficult to detect the flaking because similar pulses come out when balls pass the defection point. The detection and classification method for inner and outer races are defected by KDI and nearest neighbor classification rule is proposed and its high performance is also shown.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.388-393
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• 2012

Vibration condition monitoring at low rotational speeds is still a challenge. Acoustic emission (AE) is the most used technique when dealing with low speed bearings. At low rotational speeds, the energy induced from surface contact between raceway and rolling elements is very weak and sometimes buried by interference frequencies. This kind of issue is difficult to solve using vibration monitoring. Therefore some researchers utilize artificial damage on inner race or outer race to simplify the case. This paper presents vibration signal analysis of low speed slewing bearings running at a low rotational speed of 15 rpm. The natural damage data from industrial practice is used. The fault frequencies of bearings are difficult to identify using a power spectrum. Therefore the relatively improved method of empirical mode decomposition (EMD), ensemble EMD (EEMD) is employed. The result is can detect the fault frequencies when the FFT fail to do it.

• 정보처리학회논문지A
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• 제9A권4호
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• pp.525-534
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• 2002

병렬프로그램에서 경합 조건은 비결정적인 수행 결과를 초래하므로 디버깅을 위해 반드시 탐지되어야 한다. 이러한 경합을 수행 중에 탐지하는 기존의 기법들은 병행성 정보 생성 시에 공유 자료구조를 사용하여 심각한 병목현상을 발생시키거나, 병행성 정보 비교 시에 내포병렬성의 정도에 의존하는 비효율적인 시간 복잡도를 가진다. 본 논문에서는 개별 자료구조를 사용함으로써 병목현상을 제거하여 병행성 정보를 확장적으로 생성하며, 생성된 병행성 정보의 비교 시간을 상수적인 복잡도로 개선한 새로운 레이블링 기법을 제안한다. 그러므로 제안된 레이블링 기법의 확장성 및 효율성은 공유메모리와 메시지전달 프로그램뿐만 아니라 이를 혼합하여 사용하는 병렬프로그램에서도 효율적인 수행중 경합탐지를 가능하게 한다.

• International Journal of Human Ecology
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• 제4권2호
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• pp.55-75
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• 2003

The purpose of this study was to investigate the effect of employment related factors on household savings for precautionary purposes when controlling for financial security and to compare the results between the two different economic periods. A conceptual framework was developed based on the precautionary saving theory, the family stress theory, and previous empirical studies. As a self-insurance, a measure of security funds were developed and used as the dependent variable. Using data on working households in the 1992 and the 1998 Survey of Consumer Finances (SCF), a MLE estimation was conducted on the pooled data. The 1992 and 1998 data were used to reflect periods of economic recession and expansion, respectively. The results suggested that factors representing resources played the most significant role in determining the amount of security funds. Some of the employment related factors, preferences, financial security, and race were also significantly affected the amount of security funds. The results suggested that stable employment conditions were important for households to accumulate security funds. Households with more human resources and financial resources had a larger amount of security funds than those that had less human and financial resources. From the findings, implications for research, policies, and financial educators had been suggested.

• 한국보건간호학회지
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• 제25권2호
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• pp.255-265
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• 2011

Purpose: The study investigated the knowledge and actual condition of sexuallytransmitted diseases(STD) in Mongoloian. Method: Data from 210 Mongolians were collected for 6days from August 10-15, 2008 using a questionnaire translated by Mongolians to identify the knowledge of STD and with permission, analysis of blood and human immuno deficiency virus(HIV) by SD Bioline Syphilis 3.2 test and SD Bioline HIV-1/2 3.0 test respectively. The data was scored by mean ${\pm}$ standard deviation. Differences were evaluated according to the subjects' general characteristics by t-test and the ANOVA. Results: The average knowledge score concerning STD 48.99(${\pm}.19$) indicated a low level of knowledge. STD was detected in six(2.9%) and HIV was four(1.9%) of the 210 subjects. General characteristics significantly different knowledge level were gender(t=-3.098, p=.002), education(F=6.090, p=.003), type of employment(F=2.443, p=.049), and sexual education experience(F=5.604, p=.004). Conclusion: Education programs to increase STD awareness and its prevention must be developed and regular health evaluations for those already have sexual transmitted disease is needed.

• 수산해양교육연구
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• 제27권6호
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• pp.1783-1796
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• 2015

The purpose of this study was to verify the formation of serious leisure experience for water sports mania using grounded theory method approach. Research participants were selected 6 water sports mania by reputational sampling method. Six participants who usually participated in water sports club were selected as research participants. The data for this study included participants' observation and in-depth interview. This study categorized the coding paradigm which was presented by using the findings derived from data as they were into casual condition, contextual element, central phenomenon, critical situation, mediative element, interaction, final result and core category to draw out the process of becoming a water sports mania and its significances. The results of were as follows. First, water sports mania recognized the environmentally safe pleasure and value. Second, water sports mania was in a race against myself. Third, water sports mania felt the social and environmental changes. Fourth, water sports mania was looking for alternative method. Fifth, water sports mania overcome physical limitations and liberation from fear of water. Lastly, water sports mania felt alive through the enthusiastic participation.

• 정보처리학회논문지D
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• 제12D권6호
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• pp.863-868
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• 2005

하드웨어와 소프트웨어를 통합 설계하는 프레임워크인 PeaCE(Ptolemy extension as a Codesign Environment)가 개발되었다. PeaCE 에서는 데이터 흐름과 제어 흐름을 모두 표현할 수 있는데, 제어 흐름은 상태 기계를 확장한 fFSM으로 나타낸다. fFSM은 계층형 상태 기계로서 제어흐름을 표현하기 위해 많은 구문을 제공하지만, 모델에 대한 의미가 정의되어 있지 않아서 명세를 검증하는데 어려움이 많다. fFSM의 의미를 정의하기 위해서, 본 논문에서는 계층형 상태 기계를 먼저 평탄화한 후에 평탄화된 모델에 대해서 단계 의미를 정의하였다. 그 결과 레이스 조건, 애매한 전이, 순환 전이 등의 주요한 버그들을 정형적으로 검출할 수 있었다.

• 정보처리학회논문지D
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• 제13D권1호
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• pp.117-124
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• 2006

UML(Unified Modeling Language)은 객체지향 모델링을 위한 언어이다 UML에 포함되어 있는 AD(Activity Diagram; 활동 다이어그램)는 워크플로우 시스템의 모델링에 적합하지만 수행 과정의 평가가 수학적이지 못하므로 수행 과정을 직관적으로 파악해야 하는 단점이 있다. 그러나 EMFG(Extended Mark Flow Graph)는 이산적인 시스템의 모델링에 적합할 뿐 아니라 수행 과정을 수학적으로 평가할 수 있다. 따라서 본 연구에서는 EMFG를 사용하여 모델링된 AD의 수행 동작을 평가하려고 한다. 우선 AD를 EMFG로 변환하는 방법에 대하여 제안하고, 변환된 EMFG의 수행을 평가함으로써 모델링된 AD의 수행완료 가능성을 평가한다. 그리고 컴퓨터 시뮬레이션을 통하여 이를 입증한다. 제안한 알고리듬은 대규모 워크플로우 시스템을 모델링한 AD의 수행완료 가능성도 쉽게 평가할 수 있는 장점이 있다.

• 정보처리학회논문지A
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• 제12A권7호
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• pp.563-570
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• 2005

하드웨어와 소프트웨어를 통합 설계하는 프레임워크인 PeaCE(Ptolemy extension as a Codesign Environment)에서는 데이터 흐름과 제어흐름을 모두 표현할 수 있다. PeaCE에서 제어 흐름을 표현하는 fFSM 명세를 정형 검증하기 위해 fFSM의 단계 의미를 정의하였다. 본 논문에서는 이전 연구에서 정의된 정형 의미를 바탕으로 개발한 자동 검증 도구를 소개한다. 이 도구는 내부 모델체커로 SMV를 사용하며 사용자는 직접 논리식을 기술하지 않고도 레이스 조건, 애매한 전이, 순환 전이 등의 주요한 버그들을 검증할 수 있다.