• 제목/요약/키워드: Characteristic variation

검색결과 1,459건 처리시간 0.033초

드럼세탁기 구동시스템 시뮬레이션을 위한 부하 모델링 (Load modeling for the drum washing machine system simulation)

  • 이정효;이병국;원충연
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2007년도 하계학술대회 논문집
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    • pp.412-414
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    • 2007
  • In motor driving, one of the most important consideration is the load characteristic and variation. Generally, the motor drive should be made enough for the current by load variation, and it should be controlled by the load weight. However, the drum washing machine's load variation is irregular and large. Therefore, we want to make the motor drive that considering this load pattern, this paper describes the drum washing machine's load pattern modeling by the mathematical theory.

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벡터제어-구동 유도전동기의 파라미터 변동에 대한 비선형 제어특성의 해석 (Analysis of Nonlinear Control Characteristic for the Parameter Variation of Vector Control-Fed Induction Motors)

  • 손진근;석원엽;송양회;전희종
    • 전기학회논문지P
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    • 제53권2호
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    • pp.51-57
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    • 2004
  • Vector control schemes are used in inverter-fed induction motor drives to obtain high performance. Crucial to the success of the vector control scheme is the knowledge of the instantaneous position of the rotor flux. However, the position of the rotor flux change with temperature and magnetic saturation of the motor. This variation cause deterioration of both steady state and dynamic operation of the motor drives. Performance degradation is in the form of input-output torque nonlinearity and saturation of the motor. Analytic expressions are derived to evaluate the effects due to parameter sensitivity. Also, dynamic response is shown by speed command with the variation of stator and rotor resistance.

정원등(lanterns)용 태양전지셀의 온도특성 변화연구 (A study on characteristic variation of solar cells for lanterns as a temperature change)

  • 이세현;박창용;조미령;신상욱;황명근;양승용
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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    • pp.233-236
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    • 2006
  • In this paper, I try to measure the electrical characteristics of PV cell for lanterns with solar simulator and simulated with PC1D software. 1 keep my eye on the characteristics variation of PV cell as a temperature change. Therefore, I try to increase a temperature of controlled block from $10^{\circ}C\;to\;50^{\circ}C$ while measuring the PV cell. As a result A variation caused by voltage have an effect on the efficacy of PV cell. Hence, it is an important variable when a designer plan to make a solar cell for lanterns.

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A method of selecting an active factor and its robustness against correlation in the data

  • Yamada, Shu;Harashima, Jun
    • International Journal of Quality Innovation
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    • 제4권2호
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    • pp.16-31
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    • 2003
  • A reducing variation of quality characteristics is a typical example of quality improvement. In such a case, we treat the quality characteristic, as a response variable and need to find active factors affecting the response from many candidate factors since reducing the variation of the response will be achieved by reducing variation of the active factors. In this paper, we first derive a method of selecting an active factor by linear regression. It is well known that correlation between factors deteriorates the precision of estimators. We, therefore, examine robustness of the selecting method against the correlation in the data set and derive an evaluation method of the deterioration brought by the correlation. Furthermore, some examples of selecting and evaluation methods are shown to demonstrate practical usage of the methods.

정원등(lanterns)용 태양전지셀의 온도특성 변화연구 (A study on characteristic variation of solar cells for lanterns as a temperature change)

  • 이세현;조미령;신상욱;황명근;양승용
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.206-209
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    • 2006
  • In this paper, I try to measure the electrical characteristics of PV cell for lanterns with solar simulator and simulated with PC1D software. I keep my eye on the characteristics variation of PV cell as a temperature change. Therefore, I try to increase a temperature of controlled block from $10^{\circ}C$ to $50^[\circ}C$ while measuring the FV cell. As a result, A variation caused by voltage have an effect on the efficacy of PV cell. Hence it is an important variable when a designer plan to make a solar cell for lanterns.

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철도차량용 LIM의 공극변화에 따른 추력/수직력 특성 분석 (A study on thrust and normal force by air-gap variation of a linear induction motor used for an urban railway transit)

  • 양원진;박찬배;이형우;권삼영;박현준;원충연
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.316-320
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    • 2008
  • A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.

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웹 객체 이질성 기반의 적응형 웹캐싱 기법 (An Adaptive Web Caching Method based on the Heterogeneity of Web Object)

  • 고일석;나윤지;임춘성
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2004년도 춘계학술발표대회
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    • pp.1379-1382
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    • 2004
  • The use of a cache for storing and processing of Web objects is becoming larger. Also, many studies on the efficient management of the storing scope of caches are being done. Web caching algorithms have many differences from traditional algorithms. Particularly, heterogeneity of Web objects that are processing units of Web caching, and a variation of Web object reference characteristic with time are the important causes of the decrease the performance of existing algorithms. In this study, we proposed the new web-caching algorithm. A heterogeneity variation of an object can be reduced as the proposed method dividedly managing Web objects and a cache scope with heterogeneity, and it is adaptively reflecting a variation of object reference characteristics with the flowing of time. In the experiments, we verified that the performance of the proposed method was more improved than existing algorithms through the two experiment models which considered heterogeneity of an object.

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간접증거성과 인식양상: 기능변이의 문제를 중심으로 (Indirect Evidentiality and Epistemic Modality: With Reference to Functional Variation)

  • 홍택규
    • 비교문화연구
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    • 제25권
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    • pp.649-678
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    • 2011
  • The purpose of this work is to explain categorial correlations between indirect evidentiality and epistemic modality on the basis of semantic, pragmatic usages of Russian so-called non-specialized lexical markers of evidentiality, such as kazhetsja, naverno, vidimo, poxozhe, dolzhno byt' etc. To do this, firstly I concentrated on the parameter of internal functional variation of a given parenthetic word. Secondly, I approached this topic from a typological perspective. Thirdly, I accepted Sweeter(1990)'s methodological assumption that etymological prototype of a given word plays a great role in grammatical, semantic, pragmatic changes. As a result, I could postulate general tendencies of grammaticalizations (or semantic, pragmatic, funtional changes) in the direction from epistemic modality to indirect evidentialty, which consists of inferentives, presumptives, and quotatives. For example, such a parenthetic word as kazhetsja can functions not only as a marker of epistemic modality of uncertainty, but also as inferentives. Besides, it is very interesting that this word lately has started to function as quotatives, too. This kind of functional variations are very characteristic in these spheres.

Frequency characteristic analysis on acoustic emission of mortar using cement-based piezoelectric sensors

  • Lu, Youyuan;Li, Zongjin
    • Smart Structures and Systems
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    • 제8권3호
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    • pp.321-341
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    • 2011
  • Acoustic emission (AE) monitoring was conducted for mortar specimens under three types of static loading patterns (cubic-splitting, direct-shear and pull-out). Each of the applied loading patterns was expected to produce a particular fracture process. Subsequently, the AEs generated by various fracture or damage processes carried specific information on temporal micro-crack behaviors of concrete for post analysis, which was represented in the form of detected AE signal characteristics. Among various available characteristics of acquired AE signals, frequency content was of great interest. In this study, cement-based piezoelectric sensor (as AE transducer) and home-programmed DEcLIN monitoring system were utilized for AE monitoring on mortar. The cement-based piezoelectric sensor demonstrated enhanced sensitivity and broad frequency domain response range after being embedded into mortar specimens. This broad band characteristic of cement-based piezoelectric sensor in frequency domain response benefited the analysis of frequency content of AE. Various evaluation methods were introduced and employed to clarify the variation characteristics of AE frequency content in each test. It was found that the variation behaviors of AE frequency content exhibited a close relationship with the applied loading processes during the tests.

시공간적, 계절적 특성을 고려한 사면에서의 토양수분의 거동파악 (Movement Analyzing of Soil Moisture at a Hillslope Scale Considering Spatial-Temporal and Seasonal Characteristics)

  • 오경준;곽용석;김도훈;김상현;김현준;김남원
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.678-682
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    • 2006
  • In order to analyze movement of soil moisture, Time Domain Reflectometry(TDR) with multiplex system has been installed at the Bumreunsa hillslope of Sulmachun Watershed to configure spatial-temporal variation pattern considering seasonal characteristic. An intensive surveying was performed to build a refined digital elevation model(DEM) and flow determination algorithms with inverse surveying have been applied to establish an efficient soil moisture monitoring system. Soil moisture data were collected through an intensive and long term monitoring 380 hrs in November of 2003 and 1037 hrs in May and June of 2004. Soil moisture data shows corresponding variation characteristics of soil moisture on the up slope, buffer, main channel zones of the hillslope which were classified from terrain analysis. Inferences and limitations of measured soil moisture data were discussed in conjunction with flow characteristic through terrain analysis.

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