• 제목/요약/키워드: segregation

검색결과 1,166건 처리시간 0.03초

Complex segregation analysis

  • Shin, Han-Poong
    • Journal of the Korean Statistical Society
    • /
    • 제3권2호
    • /
    • pp.103-115
    • /
    • 1974
  • During the last few years there has been an interest in models for qualitative attributes, where complex signifies that affection may be caused in two or more ways [1-3]. These models have in common the prediction of variable recurrence risks among families with given parental phenotpes. Segregation analysis has covered only a few cases [4,5]. The present paper extends segregation analysis to three complex models under two mode of ascertainment.

  • PDF

커패시터 구동형 단상 유도전동기의 손실분리 연구 (Study of Losses segregation for Capacitor-Run Single phase Induction Motor)

  • 김광수;김기찬;이상훈;이주
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
    • /
    • pp.16-18
    • /
    • 2008
  • Several methods are proposed in the literature for losses segregation of single phase induction motor. Generally we could divide two methods for experimental determination of losses segregation for single phase induction motor. The one is relatively complicated method based on Parameter estimation of single phase induction motor. The other is simple method based on IEEE Standard 114. Segregation of losses in single phase induction motor is more complicated than that in three phase induction motor, because of the backward magnetic field component in the motor and multiplicity of different single phase type. In this paper, therefore, we studied losses segregation of capacitor-run single phase induction motor.

  • PDF

분리저감형 유동화제를 이용하는 고유동 콘크리트의 특성에 미치는 플라이애쉬의 영향 (Influences of Fly ash on the Properties of High Flowing Concrete Using Segregation-Reducing Type Superplasticizer)

  • 윤길봉;전충근;손성운;김성수;한천구
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
    • /
    • pp.661-664
    • /
    • 2000
  • It is known that high flowing concrete performs much higher fluidity, segregation resistibility and better placeability than normal concrete. However, it is hard to apply high fluidity concrete in field because of high manufacturing cost. Therefore, we intend to investigate the validity of segregation reducing type superplasticizer which is made by combining 0.61 of viscosity agent and 0.022 of AE agent for 1 of superplasticizer. Test are conducted on high flowing concrete using fly ash by applying segregation reducing type superplasticizer. According to experimental results, As contents of fly ash increase, fluidity, segregation resistibility and placeability shows favorable results. And also compressive strength at early age shows to be retarded, while it gains high strength at later age.

  • PDF

고액공존재료의 변형거동에서 재료의 크기가 액상편석에 미치는 영향 (The Effect of Test Peace Size on Liquid Segregation in deformation Behavior in Mushy state Material)

  • 윤성원;서판기;강충길
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 추계학술대회 논문집
    • /
    • pp.167-170
    • /
    • 1997
  • For the optimal net shape forging of semi-solid materials (SSM), it is important to predict the deformation for variation of strain rate. It should be necessruy to conduct a formation of stress-strain curve in semi-solid alloys for analysis of the thixoforming process. Particularly, important problem to application of computer aided engineering in SSM processing is to prevent a segregation of liquid component during compression process. The liquid segregation is studied as multistage change of the strain rate and test piece size to prevent the liquid segregation during the compression process. The compression test for semi-solid aluminium alloy with a controlled solid fraction is performed by dynamic material test system with a furnace. Moreover morphology of structure and fraction of pore are investigated through compression test.

  • PDF

용탕단조한 Al-7%Si-0.3% Mg합금 봉상시료의 편석거동 (Segregation of Squeeze Cast Al-7% Si-0.3% Mg Alloy Bars)

  • 김기영;기석도;박종락
    • 한국주조공학회지
    • /
    • 제13권1호
    • /
    • pp.71-80
    • /
    • 1993
  • Squeeze casting has advantages to improve mechanical properties of nonferrous castings without losing high productivity. Sound pore free structure makes it possible to be subjected to heat treatment and welding. This process became popular to produce lighter automobile parts alternating cast iron parts. It has, however, two disadvantages of segregation and scattered structure due to the solidified layers in sleeve. In this study segregation behavior of squeeze cast Al-7%Si-0.3%Mg alloy bars was investigated using HVSC machine under various injection conditions. Degree of segregation decreased with injection pressure and effect of injection velocity on it was small. Segregation mode of solute was strongly governed by solidification mode and flow pattern.

  • PDF

Modeling on Hydrogen Effects for Surface Segregation of Ge Atoms during Chemical Vapor Deposition of Si on Si/Ge Substrates

  • Yoo, Kee-Youn;Yoon, Hyunsik
    • Korean Chemical Engineering Research
    • /
    • 제55권2호
    • /
    • pp.275-278
    • /
    • 2017
  • Heterogeneous semiconductor composites have been widely used to establish high-performance microelectronic or optoelectronic devices. During a deposition of silicon atoms on silicon/germanium compound surfaces, germanium (Ge) atoms are segregated from the substrate to the surface and are mixed in incoming a silicon layer. To suppress Ge segregation to obtain the interface sharpness between silicon layers and silicon/germanium composite layers, approaches have used silicon hydride gas species. The hydrogen atoms can play a role of inhibitors of silicon/germanium exchange. However, there are few kinetic models to explain the hydrogen effects. We propose using segregation probability which is affected by hydrogen atoms covering substrate surfaces. We derived the model to predict the segregation probability as well as the profile of Ge fraction through layers by using chemical reactions during silicon deposition.

광물질 혼화재 치환이 고유동 콘크리트의 재료분리 저항성에 미치는 영향 (Influence of High Fluidity Concrete on Segregation Resistance When Replacing Mineral Admixture)

  • 이혁주;이영준;현승용;한인덕;한동엽;한민철
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
    • /
    • pp.139-140
    • /
    • 2019
  • In this study, we considered the influence on segregation resistance at the time of substitution of FA and BS, which are substance admixtures of high fluidity concrete. According to the research results, EIS, which is an index of segregation in high fluidity concrete replacement, showed a low value, and the composition also showed a higher value than OPC. Therefore, it is confirmed that the resistance to segregation at the time of admixture replacement of high fluidity concrete is improved.

  • PDF

커패시터 구동형 단상유도전동기의 손실분리에 대한 연구 (Study on Losses Segregation for Capacitor-Run Single Phase Induction Motor)

  • 김광수;김기찬;이성구;고성철;전연도;이철규;이주
    • 전기학회논문지
    • /
    • 제57권9호
    • /
    • pp.1546-1551
    • /
    • 2008
  • This paper is concerned with the problems of accurate losses segregation in capacitor-run single phase motor. Segregation of losses in single phase induction motor is more complicated than that in three phase induction motor, because of the backward magnetic field component in the motor. Generally there are two methods for losses segregation of single phase induction motor. The one is relatively complicated method based on parameter estimation of single phase induction motor. By the way, the other one is simplified method based on IEEE Standard 114. All of the methods for the experimental determination of single phase induction motor losses are studied in this paper. Since the IEEE Standard is not possible to be applied for all type of single phase induction motors, we modified that method to apply for losses segregation of capacitor-run single phase induction motor as unifying the method based on parameter estimation.

MTV를 적용한 아스팔트 포설에서 열분리 저감 효과 (Effect of Thermal Segregation Reduction in Asphalt Paving with MTV)

  • 권기철
    • 한국도로학회논문집
    • /
    • 제20권4호
    • /
    • pp.1-6
    • /
    • 2018
  • PURPOSES : The objective of this study is to evaluate of the effect of thermal segregation reduction in asphalt paving using material transfer vehicles (MTVs). METHODS : Asphalt paving using MTVs was carried out, and the paved surface temperature was measured using an infrared camera. The amount of thermal segregation was estimated from temperature variations. RESULTS : The transportation of hot mix asphalt (HMA) using dump trucks caused temperature segregation that persisted in the paving surface if an MTV was not used. The average temperature variation was 8.58% in paved surfaces where an MTV was not used. However, the temperature variation was 3.10%, 2.86%, and 4.53% for the base layer, inter-layer, and surface layer, respectively, when an MTV was used. CONCLUSIONS : The use of an MTV in asphalt paving reduces thermal segregation approximately 2.3 times in an asphalt mat via a remixing process and also allows for a smoother work process because the paver never needs to stop to receive HMA. However, MTV equipment without pre-heating devices requires careful temperature control during the warm up process at the MTV during construction in the winter.

용접 저온균열 감수성에 미치는 중심 편석의 영향 (Effects of Center Segregation on Weld Cold Cracking Susceptibility)

  • 안영호;이종봉;장래웅;소문섭
    • Journal of Welding and Joining
    • /
    • 제12권2호
    • /
    • pp.87-96
    • /
    • 1994
  • Correlation between microstructural features and segregation of elements (Si, Mn, P and S) near the mid of thickness in the base metal and the synthetic HAZ was investigated. Furthermore, the relationship between the degree of center segregation and weld cold cracking susceptibility in the thickness direction was also conducted by evaluating the effect of P concentration on the critical applied stress. The results obtained are as follows: 1) Pearlite band, containing the MnS type inclusion and a locally transformed structure with a higher hardness, was observed in the center segregation region. 2) By the weld thermal cycle, center segregation region was transformed to the white band which had a higher hardness than that of base metal due to a greater hardenability of concentrated Mn, P etc.. 3) Weld cold cracking susceptibility in the thickness direction was mainly dependent on the concentration of impurity elements rather than on the number of the segregated particles near the mid of thickness. 4) During welding, the higher concentrated region was easily changed into white band. Therefore, it could be predicted that the initiation and propagation of a cold crack would be promoted by increasing the restraint stress and hydrogen content.

  • PDF