• 제목/요약/키워드: 1/4 scale model

검색결과 1,200건 처리시간 0.026초

트롤그물의 기본 성능에 관한 고찰 (Study on the basic efficiency of trawl net)

  • 오택윤;김영승;최석관;배재현;조삼광;박창두;안희춘;신종근;양원석;문대연
    • 수산해양기술연구
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    • 제42권3호
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    • pp.148-157
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    • 2006
  • A model experiment, simulation test using personal computer and real sea trial fishing were carried out to investigate the basic efficiency of bottom trawl net which can be used in the sea mount of North West Pacific, and experimental values were analyzed as the values of full-scale bottom trawl net. Hydrodynamic resistance for the full-scale trawl net according to the Koyama equation was 2.1 times higher than that of simulation and 2.4 times higher than that of model experiment at the average towing velocity. At the 3.5kt's of towing speed, net width of the full-scale trawl net was 2.5% smaller than that of simulation and 8.2% larger than that of model experiment. On the fishing experiment of the full-scale trawl net for the 3.5kt's of average towing speed, average net height of A group(same direction with external force) was 423.5% higher than that of model experiment and 457.1% higher than that of simulation and that of B group(opposite direction with external force) were 283.8% and 306.3% higher than in case of model experiment and Simulation respectively. Net mouth of the full-scale trawl net was 338.1-504.6% higher than those of model experiment and simulation in A group, and 525.2-745.3% higher in B group.

고성장 전기·전자사업의 경영효율성 (Management Efficiency of High-growth Electrical and Electronics Industry)

  • 강다연;이기세
    • 한국콘텐츠학회논문지
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    • 제19권8호
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    • pp.151-158
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    • 2019
  • 국내 전기 전자 산업이 보유하고 있는 높은 기술력은 국외 시장에서도 인정받고 있지만 현재 주변국과의 기술경쟁 등이 갈수록 심화되어져 가고 있는 상황이다. 따라서 이들 기업들이 경쟁우위를 차지하기 위해서는 무엇보다 운영상의 비효율성을 재정비하여 효율적인 생산 활동을 실시하여야한다. 이에 본 논문에서는 DEA 기업을 통해 국내 고성장 전기 전자사업의 경영효율성을 분석하며 비효율적인 기업의 투사값을 제시하며 벤치마킹의 대상이 될 수 있는 기업들의 참조집합을 확인하고자 한다. 이를 위해 총 20개 고성장 전기 전자기업들의 CCR와 BCC모형의 효율성과 규모수익성(RTS)을 분석하였다. 분석결과 BCC 효율성이 1인 기업은 총 12개, CCR 효율성이 1인 기업은 총 4개 기업으로 나타났다. 그리고 BCC, CCR 효율성이 모두 1인 기업은 총 4개 기업이었다. 또한 기업의 규모수익성은 IRS가 11개 기업, CRS가 6개 기업 그리고 DRS가 3개 기업으로 분석되었으며 참조빈도 분석에서는 BCC모형에서는 4개 기업과 CCR 모형을 통해 4개 기업을 벤치마킹이 할 수 있는 기업으로 제시하였다. 이러한 결과는 동종 산업의 후발 기업들에게 기업의 운영환경을 개선할 수 있는 유용한 정보가 될 것이다.

HOME, 사회인구론적 변인과 아동의 지적, 사회적 능력간의 관계분석 I -만 4세 아동을 대상으로- (Analysis of the Relationship of HOME, Socio-demographic Variables and Children's Intellectual and Social Abilities I - at Age Four -)

  • 정영애
    • 대한가정학회지
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    • 제27권1호
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    • pp.181-194
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    • 1989
  • This study examined the characteristics of the relationship of HOME, socio-demographic variables and children's intellectual and social abilities. The subjects of this study were 80 children at age four and their mothers. Instruments included inventory of home stimulation (HOME) and the inventory of socio-demographic variables and K-Binet scale, social naturation scale, and the social-emotional developmental rating scale. The results obtained from this study were as follows: 1. HOME, socio-demographic variables had a significant positive correlation (.37∼..66) with children's intellectual ability. 2. HOME, Socio-demographic variables had a significant positive correlation(.26∼..67) with children's social ability. 3. The variables that significantly predicted children's intellectual ability were play materials, breadth of experience and quality of langage environment. 4. The variables that significantly predicted children's social ability were play materials, economic status of the home and parent education. 5. The results of the causal model showed that the kind of variables that affected children's intellectual ability directly were direct stimulation, parent's education, indirect stimulation, and the emotional climate of the home. 6. The results of the analysis of the causal model showed that the kind of variables that affected children's social ability directly were direct stimulation, parent's education, economic status of the home.

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Blink reflex changes and sensory perception in infraorbital nerve-innervated areas following zygomaticomaxillary complex fractures

  • Park, Young Sook;Choi, Jaehoon;Park, Sang Woo
    • Archives of Plastic Surgery
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    • 제47권6호
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    • pp.559-566
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    • 2020
  • Background Infraorbital nerve dysfunction is commonly reported after zygomaticomaxillary complex fractures. We evaluated sensory changes in four designated areas (eyelid, nose, zygoma, and lip) innervated by the infraorbital nerve. This evaluation was conducted using the static two-point discrimination test and the vibration threshold test. We assessed the diagnostic significance of the blink reflex in patients with infraorbital nerve dysfunction. Methods This study included 18 patients, all of whom complained of some degree of infraorbital nerve dysfunction preoperatively. A visual analog scale, the infraorbital blink reflex, static two-point discrimination, and the vibration threshold were assessed preoperatively, at 1 month postoperatively (T1), and at a final follow-up that took place at least 4 months postoperatively (T4). The results were analyzed using a multilevel generalized linear mixed model. Results Scores on the visual analog scale significantly improved at T1 and T4. The infraorbital blink reflex significantly improved at T4. Visual analog scale scores improved more rapidly than the infraorbital blink reflex. Two-point discrimination significantly improved in all areas at T4, and the vibration perception threshold significantly improved in the eyelid at T4. Conclusions Recovery of the infraorbital blink reflex reflected the recovery of infraorbital nerve dysfunction. We also determined that the lip tended to recover later than the other areas innervated by the infraorbital nerve.

표상적 관계에 대한 영유아의 이해와 발달 (Development of Young Children's Understanding of Representational Relations)

  • 박찬형;이종희
    • 아동학회지
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    • 제32권1호
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    • pp.51-69
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    • 2011
  • This study examined how young children understand representational relations between referents and their representational objects. Ninety-four children aged 2- to 4.5-years of age were individually tested; firstly in the scale-model tasks, and then in the scale-map tasks. Data were analyzed both by means of Chi-Square test and by a more descriptive, micro analysis. According to the results, there were significant age differences in the understanding of representational relations, regardless of the type of representational objects. In the descriptive, micro analysis, it was found that before 3 years of age, young children have a great deal of difficulties in understanding representational relations. More importantly, young children under three seemed unable to understand representational relations, especially when the similarities as well as the differences between the representational object and the referent were very high. These results suggest that teachers of very young children need to select representational materials carefully, taking into consideration children's understanding of representational relations.

공간 상호작용 모델에 대한 공간단위 수정가능성 문제(MAUP)의 영향 (Effects of the Modifiable Areal Unit Problem (MAUP) on a Spatial Interaction Model)

  • 김감영
    • 대한지리학회지
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    • 제46권2호
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    • pp.197-211
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    • 2011
  • 공간 상호작용의 복잡성, 공간적 재현과 모델링의 필요성에 의해서 공간 상호작용 데이터의 합역이 불가피하다. 이러한 상황에서 본 연구의 목적은 공간 상호작용 데이터를 스케일을 달리하여 합역하거나 혹은 동일 스케일에서 합역 방식을 달리하여 합역하였을 때, 공간 상호작용 모델의 결과가 어떻게 달라지는지 평가하는 것이다. 공간 상호작용 데이터의 합역은 공간단위 수정가능성의 문제(Modifiable Areal Unit Problem: MAUP)를 야기한다. 공간 상호작용 데이터의 합역을 위하여 무작위로 구역 시드를 선정한 후 인접한 공간단위를 할당하는 방법, 구역 시드와 공간단위 사이의 연구 가중 거리를 최소화하는 방법, 구역 내 상호작용 비율을 최대화하는 방법, 구역 내 상호작용 비율을 최소화하는 방법을 사용하였다. MAUP의 영향을 평가하기 위한 공간 상호작용 모텔로 기원지-목적지 제약 포아송 회귀 모델을 이용하였다. 분석 결과는 모델 잔차의 공간적 특성뿐만 아니라 파라미터 추정값, 적합도 등이 MAUP의 영향을 받는다는 것을 보여주었다. 모델은 합역 방식 보다는 합역 수준에 더 민감하게 반응하였고, 모델에 대한 스케일 효과는 구획 방식에 따라 상이하게 나타났다.

제주도 주변해엽 고등어 포착망의 연구 - 1 . 정수에 있어서 망형 변화에 관한 모형실험 - (Studies on the Mackerel Purse Seine Operation in the Sea Area of Cheju Island - 1 . Model Experiment on the Changes of Net Shape in Stagnant Water -)

  • 박정식
    • 수산해양기술연구
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    • 제22권2호
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    • pp.7-15
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    • 1986
  • In order to investigate the performance for the mackerel purse seine of one boat purse seiner using in the sea area of Cheju Island, a model net is made of the scale of 1/400 of its full scale, and model test on the shape of net and the tension of purse line is carried out in the stagnant water channel of the circulating water tank. Designing and testing for the model net are based on the Tauti's law. The obtained results are as follows; 1. The sinking rate of net is maximized the value of 6.40 m/min from 5 to 10 minutes after shooting net, and the mean value is 6.13 m/min. 2. The enclosed area formed with the float line after pursing operation is 76-84% of the area which is formed immediately after the shooting operation. At that time, purse seine is pulled inward the circle of surrounding net about 26.5% of the diameter. 3. In operating, when longitudinal section area of the central part of the net is maximized, the split area of both the wing-ends is 31-32% of the former. 4. When the time for the completing of pursing is 20 minutes, the maximum tension of the purse line is about 10.2 tons.

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충격반향기법을 이용한 암반근입 현장타설말뚝의 선단조건 평가 (Assessment of End Condition of Drilled Shafts Socketed into Rock by Impact Echo Test)

  • 김형우;김동수;김원철
    • 한국지반공학회논문집
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    • 제18권4호
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    • pp.21-32
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    • 2002
  • 말뚝 선단 조건에 따른 충격반향기법의 시간영역 신호를 실내 모형실험에 의하여 분석하였다. 선단조건으로는 자유단, 고정단, 암반 근입, 연약 선단부의 네 가지 조건을 고려하였으며, 이를 위하여 폴리우레탄 재질의 모형말뚝과 모노캐스트 재질의 모형암반을 제작하여 실험을 수행하였다. 실내실험 결과 각각의 경계조건에 대한 신호의 특성을 파악할 수 있었으며, 말뚝 선단 조건뿐만 아니라 말뚝과 주변 암반과의 부착상태도 추정할 수 있는 가능성을 확인하였다. 또한 실내 모형실험의 결과를 검증하기 위하여 현장실험을 수행하였으며, 암반 근입 말뚝에 대한 신호 분석 결과 충격반향기법에 의한 현장타설말뚝의 비파괴 건전도 평가는 적용성이 충분히 있는 것으로 파악되었다.

수평평판위 의 혼합대류 열전말 계산 을 위한 4-방정식 모델 의 개발 (Development of four-equation turbulence model for prediction of mixed convective heat transfer on a flat plate)

  • 성형진;정명균
    • 대한기계학회논문집
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    • 제7권2호
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    • pp.193-203
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    • 1983
  • The mixed convective heat transfer problems are characterized by the relatively significant contribution of buoyancy force to the transport processes of momentum and heat. Past analytical studies on this kind of problems have been carried out by employing either the conventional R-.epsilon. turbulence model which includes constant turbulent Prandtl number .sigma.$_{+}$ 1 or an extended R-.epsilon. turbulence model which takes account of the buoyancy effect in appropriate length scale equations. But in the latter case, the temperature variance .the+a.$^{2}$ over bar is approximated by a model under local equilibrium condition and the time scale ratio between velocity and temperature is assumed to be constant. These approximation is known to break down when the buoyancy effect is dominant. The present study is aimed at development of new computational turbulence closure level which can be applied to this rather complex turbulent process. The temperature variance is obtained directly by solving its dynamic transport equation and the time scale ratio which is variable in space is computed by a solution of a dynamic equation for the rate of scalar dissipation .epsilon.$_{\thetod}$ It was found that the computational results are in good agreement with available experimental data of wide range of unstable conditions.

패션브랜드자산의 형성과정에 관한 연구: 캐주얼 브랜드를 중심으로 (The Conceptual Framework of Building Fashion Brand Equity; Focused on casual wear brand)

  • 김혜정;임숙자
    • 한국의류학회지
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    • 제28권2호
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    • pp.252-261
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    • 2004
  • In this complex marketing world, marketers find themselves having to grapple with difficult issues about branding and their brand management. In many cases, a deeper understanding of how consumers feel, think, and act could provide valuable guidance to address these brand-management challenges. The objective of this study is to conceptualize and test the framework of building fashion brand equity, utilizing Keller's CBBE Model as a theoretical framework and Kim and Lim's (2002) scale as a measurement model of fashion brand equity. We conducted a survey toward 696 university students using Kim and Lim's fashion brand equity scale. To test the hypothesized building paths of fashion brand equity, statistical analyses were performed with AMOS 4.1 program using confirmatory factor analysis and structural equation model. The results of this study were as follows. First, fashion brand equity was defined in terms of six components; customer-brand resonance, customer feeling, customer judgment, brand imagery. brand performance and brand awareness. Fashion brand equity was multi-dimensional brand attitude, which could be measured by 16 items. Consequently, Kim and Lim's scale acquired a statistical validity. Second, the proposed conceptual framework of this study was partially significant. We can provide an effectiveness of Keller's CBBE model to conceptualize the building process of fashion brand equity. Third, it was different between two brands to build fashion brand equity.