• 제목/요약/키워드: Internal variable

검색결과 797건 처리시간 0.025초

내부제어밸브를 가진 가변 사판식 압축기의 소음개선에 관한 연구 (A Study of Noise Improvement of variable displascement swash plate type compressor with internal control valve)

  • 한규석;노경덕;공문성
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.165-168
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    • 2006
  • Due to the distinct advantages of comfort, drive ability and fuel economy standard, the variable displacement swash plate type compressor which can control the compressor displacement by increasing of reducing the swash plate angle has developed for automotive air-conditioning system. That can be obtained constant temperature of car room on the variation cooling capacities of engine speeds. In this paper we investigated the improvement of internally controlled variable displacement swash plate compressor on noise.

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Analytical design of constraint handling optimal two parameter internal model control for dead-time processes

  • Tchamna, Rodrigue;Qyyum, Muhammad Abdul;Zahoor, Muhammad;Kamga, Camille;Kwok, Ezra;Lee, Moonyong
    • Korean Journal of Chemical Engineering
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    • 제36권3호
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    • pp.356-367
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    • 2019
  • This work presents an advanced and systematic approach to analytically design the optimal parameters of a two parameter second-order internal model control (IMC) filter that satisfies operational constraints on the output process, the manipulated variable as well as rate of change of the manipulated variable, for a first-order plus dead time (FOPDT) process. The IMC parameters are designed to minimize a control objective function composed of the weighted sum of the error between the process variable and the set point, and the rate of change of the manipulated variable, and to satisfy the desired constraints. The feasible region of the constrained IMC control parameters was graphically analyzed, as the process parameters and the constraints varied. The resulting constrained IMC control parameters were also used to find the corresponding industrial proportional-integral controller parameters of a Smith predictor structure.

정보시스템 사용에 대한 내부통제 효과성이 정보역량에 미치는 영향에 관한 연구

  • 이재범;김상수;이재철
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2007년도 추계학술대회 및 정기총회
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    • pp.58-63
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    • 2007
  • Recently, as the management environments are changing rapidly and the uncertainty is becoming larger, the needs of internal control for management and IS become stronger. In order to construct a new internal control system for IS, it is necessary to evaluate the former research of the system. This study emphasizes the importance of effective internal control system, presents a conceptual framework for the preceding factors to consider, and verifies empirically the framework. This study sets the organization citizenship behavior, IS innovation resistance, and IT capability from the viewpoint of Socio-Technical system as the preceding factors for the effectiveness of internal control system. A research model, affecting the above factors on IS capability as a mediating variable of the internal control effectiveness for the use of IS, is set up. PLS-Graph 3.0 is used to verify the model. We found that the internal control effectiveness have affirmative effect on information capability, a surrogate variable of the IS effectiveness and a mediation effect is meaningful.

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간호단위의 내부마케팅요인이 간호사의 조직시민행동에 미치는 영향 - 직무만족을 매개변수로 - (The Influence of Internal Marketing Factors on Organizational Citizenship Behavior of Nurses - Mediation Effect of Job Satisfaction -)

  • 장경화
    • 동서간호학연구지
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    • 제13권1호
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    • pp.31-39
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    • 2007
  • Purpose: This study was to identify the influence of internal marketing factors on organizational citizenship behavior of nurses based on the mediate variable of job satisfaction. Method: Structured questionnaires were used with a convenience sample of 267 subjects working at 2 hospitals which have more than 500beds. The data were analyzed using descriptive statistics, ANOVA, Scheffe test, Pearson's correlation and multiple regression. Result: Empowerment($\beta$= .395) and compensation($\beta$= -.232) among the internal marketing factors had significant influences on organizational citizenship behaviors. However, job satisfaction($\beta$= .266) showed a mediate variable between compensation and organizational citizenship behaviors. Conclusion: This result indicates that empowerment and job satisfaction are important factors in predicting organizational citizenship behavior of nurses in hospitals. Thus it would be necessary to include this two factors in inhencing production of a nursing unit.

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The influence of guide vane opening on the internal flow of a francis turbine

  • Wei, Qingsheng;Choi, Young-Do
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권3호
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    • pp.274-281
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    • 2013
  • The variable demand on the energy market requires a great flexibility in operating hydro turbines. However, Francis turbine operated at off-design conditions poses technical challenges related to large unsteady forces given by residual swirl and angular momentum. In order to improve the performance of a Francis turbine, the paper presents a numerical investigation of the 3D flow in the turbine at off-design conditions and discusses the influence of variable guide vane openings on the internal flow of a Francis turbine with the help of computational fluid dynamics. First, the internal flow characteristics of Francis turbine operated by varied guide vane angle at off design condition are computed and the optimal guide vane angle is obtained. Secondly, the Francis turbine is operated with guide vane number varies at the optimal guide vane angle. Finally, pressure contours and velocity distributions in the distributor are discussed and compared.

ANP 기반 도시환경정비사업의 변화관리 요인 도출 및 중요도 산정 (Deduction of Change Management Factors and Weight Estimation based on ANP in Urban Renewal Project)

  • 신승윤;손명진;현창택
    • 한국건설관리학회논문집
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    • 제14권3호
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    • pp.176-186
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    • 2013
  • 대규모로 진행되는 도시환경정비사업의 경우, 다수의 참여주체의 요구 및 내/외부적인 요인에 의하여 사업의 환경, 주체, 법규, 계획 등이 빈번히 변화되는 특성을 지닌다. 이처럼 대규모로 진행되는 도시환경정비사업에서는 다수의 변화의 가능성을 가지고 있는 만큼, 전체 사업의 업무프로세를 기반으로 변화요인을 정의하여 사업추진단계별로 발생 가능한 변화요인을 사전에 인지하고 체계적으로 관리할 수 있는 방안이 필요한 실정이다. 따라서 본 연구에서는 도시환경정비사업과 같이 다수의 변화 가능성이 내재된 사업의 체계적인 변화관리를 위하여, 업무프로세스를 기반으로 주요 변화관리 요인을 도출하였다. 또한 ANP방법론을 활용하여 도출된 변화요인들에 대한 외적, 내적 특성을 반영함으로써 사업 추진단계별 특성화된 주요 변화요인들의 중요도를 정량적으로 제시하였다.

내력상태계수 개념을 도입한 철근콘크리트 보의 전단파괴 트러스모델에 관한 연구 (A Study on Truss Model Incorporated with Internal Force State Factor for Shear Failure Mechanism in slender RC Beam)

  • 정제평;김우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.609-614
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    • 2001
  • This paper is to explain reasonable shear behavior that can apply usually to reinforced concrete beams on the basic concepts of existent analysis and experimental research information. This study is succession $paper^{2) 3) 4) 5)}$ of treatise announced in existing and main control variable of reinforced concrete beams with stirrups used internal force state factor($\alpha$). Shear failure of reinforced concrete beams with stirrups is Influenced greatly because of the actual geometrical shape(a/d) of the concrete and flexural reinforcement steel ratio, stirrup reinforcement ratio and concrete compression strength, size effect etc. Therefore, shear behavior of reinforced concrete beams with stirrups that flexural crack is happened can be explained easily through proper extent proposal of internal force state factor($\alpha$) that express internal force state flowing. Use existent variable truss model by analysis model to explain arch action. Also, wish to compose each failure factors and correlation with internal force state factor by function, and when diagonal cracks happens, internal force state factor($\alpha$) study whether shear stress and some effect are.

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내시경으로 절제한 십이지장 Brunner선 선종 1예 (A Case of Duodenal Brunner's Gland Adenoma Treated by Endoscopic Rescetion)

  • 김성준;구민근;박준석;김경옥;이시형;김태년;최준혁
    • Journal of Yeungnam Medical Science
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    • 제28권1호
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    • pp.84-89
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    • 2011
  • Brunneroma, also known as Brunner's gland adenoma or harmatoma, is a very rare benign tumor of the duodenum, which is usually asymptomatic, and is discovered incidentally during endoscopic exam. These lesions are most commonly located in the duodenal bulb and clinical manifestations are variable. We report on a case of a large Brunner's gland adenoma in a 54-year-old man, which was successfully removed by endoscopic resection without complications, such as bleeding or perforation. Microscopically, it was composed entirely of variable Brunner's gland.

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Analysis of leakage factors affecting ECV performance in variable compressor

  • Mahmud, Md. Iqbal;Cho, Haeng Muk
    • 에너지공학
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    • 제23권4호
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    • pp.183-188
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    • 2014
  • Solenoid operated electromagnetic control valve (ECV) using in an external variable displacement swash plate type compressor is widely used for air conditioning control system because of its low energy consumption and high efficient characteristics. ECV controls the entire vehicle air conditioning system by means of a pulse width modulation (PWM) system that supplied from an external controller. Different pressure ports located within ECV has important functions to control the air/refrigerant flow through its internal passages. The flow paths are preciously maintained with acceptable ranges of leakage (gap) between the parts inside it which is followed by effective design and critical dimensioning of its internal features. Therefore, it saves energy losses from the solenoid operation as well as ensures the balance of forces within it. The research paper highlights analysis of the leakages (at different pressure ports) and dimensioning tolerance factors that affects the ECV performance.

소비자 정보원에 따른 정보탐색량과 구매후 만족에 관한 연구 -서울특별시 주부 소비자의 냉장고 구매를 중심으로- (A Study on Amount of Information Search and Consumer's Post-purchase Satisfaction according to Consumer Information Sources)

  • 이일경;이기춘
    • 가정과삶의질연구
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    • 제10권1호통권19호
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    • pp.27-42
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    • 1992
  • This study focused on consumer information search activity and consumer's post-purchase satisfaction. For these purpose, a survey was conducted suing questionaires on 430 homemakers that lived in seoul. Statistics used for data were Frequency Distribution. Percentile, Mean, One-way AAANOVA., Scheffe-test, T-test, Pearson's correlation. Multiple Regression Analysis and Multiple Classification Analysis. The major findings were ; 1) The level of each amount information search was lower than average. And the level of consumer's post-purchase satisfaction was a little higher than average. 2) On amount of "noncommercial-personal" information search, the influencing variables were desire to seek information, education, brand royalty in turn. These three variables explained 7% of dependent variable's variance. 3) On amount of "noncommercial-media" information search, the influencing variables were desire to seek information, amount of internal information, education, occupational status in turn. These variables explained 14% of dependent variable's variance. 4) On amount of "commercial-personal" information search, the influencing variable was desire to seek information, and this variable explained 3.1% of dependent variable'a variance. 5) On amount of "commercial-media" information search, the influencing variables were desire to seek information, education, amount of internal information in turn. These three variables explained 12.1% dependent variable's variance. 6) Resulting from multiple classification analysis, influencing variables on consumer's post-purchase satisfaction were amount of noncommercial-media information search and printed media search, and brand royalty. These three variables explained 9% of dependent variable's variance. Furthermore, througout all the subareas of consumer's satisfaction, the amount of noncommercial-media information search was the most influencing variable.

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