• 제목/요약/키워드: 1/4 scale model

검색결과 1,200건 처리시간 0.032초

제한투기시설에서 배출되는 여수의 거동 (The Behavior of Effluent Discharged from the Confined Dumping Facility)

  • 정대득;이중우
    • 한국항만학회지
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    • 제14권4호
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    • pp.429-439
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    • 2000
  • The primary purpose of dredging work is to maintain navigational readiness and to increase environmental amenity. Therefore the dredging project, which is composed of excavating, removing, transporting and storing or dumping dredged material, must be carefully managed to insure that dredging works are completed in a cost-effective and environmentally safe method. The most important point in dumping operations is evaluating and decreasing the impacts of dumping works at the dumping area. One of the most effective method for this purpose is using the schematic process composed of the sophisticate plan, precise work and predicting/reducing the impacts based on an numerical model being closely linked with field observation. In this study, a numerical model is used to predict the spatial transport and fate of the effluent discharged from the confined dumping facility(CDF) located at a coastal area. To achive this purpose, numerical models were used for reappearing the tidal current of concerned area. These models were then applied to Mokpo harbpr where capital dredging and maintenance dredging are being conducted simultaneously and the CDF is under construction. In series of model case study, we found that the effluent discharged from CDF was governed by the receiving water condition and outfall geometry, so that limit of near-field was 14∼500 meter down stream and 4∼150 meter in transverse direction. dilution ranged from 1.1 to 8.2 on the cases. Long-term diffusion characteristics was governed by the dilution rate during near-field behavior, ambient conditions and CDF operation modes.

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LOA 47.7m급 쌍동선의 저항 및 내항 시험 (Resistance and Seakeeping Tests of a LOA 47.7m Class Catamaran)

  • 전호환;정용관;정성섭;장용훈;하상훈;김진문
    • 대한조선학회논문집
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    • 제36권4호
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    • pp.56-63
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    • 1999
  • 47.7m급 쌍동선의 1/21.5 축척 모형선으로 예인수조에서 저항 및 내항성능 시험을 수행하였다. 저항 시험은 선미트림탭을 부착하여 트림탭각의 변화에 따른 트림 및 저항변화를 조사하여 트림 탭이 없는 경우와 비교하고 그 영향을 조사하였다. 해상상태 3,4 및 5에서 3가지 실선속력에 대해서 상하 및 종운동을 계측하였으며 갑판위 5점에서 수직가속도도 계측하였다. 측정한 가속도 값은 ISO 2631/3의 규정과 비교하여 설계선형의 우수함을 보였다.

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다중 회귀분석 기반 도시형 생활주택의 공사기간 산정 모델 개발 (Development of a Model for Calculating the Construction Duration of Urban Residential Housing Based on Multiple Regression Analysis)

  • 김준상;김영석
    • 토지주택연구
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    • 제12권4호
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    • pp.93-101
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    • 2021
  • 국내 소규모 가구가 점차적으로 증가함에 따라 소규모 가구를 위한 주거공급 정책에 대한 중요성이 높아지고 있다. 이러한 중요성에 따라 정부에서는 소규모 가구를 위한 도시형 생활주택을 지속적으로 공급해오고 있다. 도시형 생활주택은 공동주택, 일반 업무시설과 동일하게 분양 및 임대 사업이므로 발주자는 프로젝트 기획단계에서 적정공사기간을 산정하는 것은 중요하다. 그러나, 선행연구에서는 대규모 건축물의 공사기간을 산정할 수 있는 모델이 존재하나 도시형 생활주택과 같은 소규모 건축물에 대한 적정 공사기간 산정 모델은 부재한 것으로 분석되었다. 따라서 본 연구의 목적은 기획단계에서 발주자가 적정 공사기간을 산정할 수 있는 다중 회귀분석 기반 도시형 생활주택의 공사기간 산정 모델을 개발 및 검증하는 것이다. 개발된 모델에 입력되는 독립변수는 연면적, 수도권, 지하층수, 지상층수, 주 건축물 수, 강원권의 총 6개이며, 개발된 모델의 수정된 결정계수(Ra2)는 0.547로 분석되었다. 개발된 모델의 성능은 RMSE의 경우 171.26일, MAPE의 경우 26.53%로 도출되었다. 본 연구를 통해 개발된 모델은 발주자에게 신뢰성 있는 공사기간 산정 결과를 제공할 수 있을 것으로 기대된다.

섬유조직염환자의 우울에 영향을 미치는 요인 (Effecting Factors on Depression in Patients with Fibromyalgia)

  • 한상숙;이상철
    • 대한간호학회지
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    • 제35권1호
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    • pp.87-94
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    • 2005
  • Purpose: The purpose of this research was to provide basic data in the control of depression found in patients with fibromyalgia by analysing the main factors that affect them. Method: The subjects were 207 out-patients in three university medical centers diagnosed with fibromyalgia according to the conditions by American College of Rheumatology (1990). Depression was measured by the CES-D Scale. Dependant variables, such as stress and anxiety were measured by the VAS Scale and physical activity was measured using 10(4-point-scale) questions developed by the researcher. The number of tender points was converted to scores based on the criteria of the ACR(1990) and of Yunus. Self-efficacy was measured by the Self-Efficacy Scale developed by Lorig et al. (1989) for arthritis patients. Result: The main factors that affect depression of patients with fibromyalgia were self-efficacy, anxiety, physical activity, tender points fatigue, and family support, which explained 49% of the depression. Conclusion: It has been confirmed that the regression equation model of this research may serve as a predictor of depression in patients with fibromyalgia.

하나원 입소 북한 이탈주민의 개인적 특성과 건강 신념이 건강 행위에 미치는 영향 (The Effects of individual Characteristics and Health Beliefs on North Korean Refugees' Health Behavior)

  • 전정희;박영숙
    • 지역사회간호학회지
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    • 제23권1호
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    • pp.82-90
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    • 2012
  • Purpose: The purpose of this study is to provide base data for preparing plans that North Korean (NK) Refugees can adjust themselves to our society with a healthy mind after they get over their health problems using the Health Belief Model, knowing the relationship between individual characteristics and health beliefs, and health behavior. Methods: The subjects were 304 NK adult refugees in Hanawon. Data were collected by demographic questionnaire, health behavior scale, self-efficacy scale, perceived benefit scale, perceived barrier scale, perceived seriousness, perceived sensibility, and individual characteristics. Results: The factors influencing the health behavior of NK refugees were perceived benefits, self-efficacy, the period in the third country and experience in being expelled to NK, and these variables were describing 31.4% of the health behaviors of refugees. Conclusion: The perceived benefits and self-efficacy of health belief and specific experiences related to refugee affected NK refugees' health behavior.

국가 역량을 고려한 효율성 기반 한국형 항공모함 규모 최적화 연구 (A Study on the Scale Optimization of the Korean-type Aircraft Carrier based on Efficiency Considering National Competency)

  • 정병기;김기태;박성제
    • 산업경영시스템학회지
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    • 제45권3호
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    • pp.49-56
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    • 2022
  • ROK Navy intends to secure the Korean-type aircraft carrier in order to effectively prepare for various future security threats. In general, the Korean national competency is considered to be at the level of having an aircraft carrier, but it is unclear what scale aircraft carrier would be appropriate. In this study, the efficiency was evaluated through the relative comparison between national competency(national power, economic power) and the scale of aircraft carriers, and the optimal scale of the Korean-type aircraft carrier that could be acquired was presented. A DEA(Data Envelopment Analysis) model was applied to aircraft carriers(19 aircraft carriers in 11 countries) currently in operation and scheduled to be possessed in the world. As input variables, CINC(Composite Index of National Capability) and GDP(Gross Domestic Product), which are the most widely used as indicators of national and economic power, and as output variables, the full-load displacement, length, and width of aircraft carriers were selected. ARIMA(short-term within 5 years) and simple regression(long-term over 5 years) were used to estimate the future national competency of each country at the time of aircraft carriers acquisition. The relative efficiency score of the Korean-type aircraft carrier currently being evaluated is 1.062, and it was evaluated as small-scale aircraft carrier compared to the national competency. Based on Korean national competency, the optimal scale of the Korean-type aircraft carrier calculated by aggregating benchmark groups, is 58,308.1 tons of full-load displacement, 279.4m in length, and 68.3m in width.

횡응모형에 의한 오차전파에 관한 연구 -공중삼각측량의 실험을 중심으로- (Studies on Error Propagation by Simulation Model -Main description of experments of aero-triangulation-)

  • 백은기
    • 한국농공학회지
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    • 제18권1호
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    • pp.4021-4037
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    • 1976
  • This paper describes the actual experiments of the error propagation and studies of analytical photogrammetry using the simulation method in which we can find the causes of the errors. These studies and the results give the valuable data which are very effective for systematically controlling the errors in aerial triangulation. The main contents in my paper are as follows: 1. Dose the scale errors in the successive models in the form of normal distribution appear when the observation errors propagate in the form of normal distribution\ulcorner 2. In what form does this scale error propagation in the actual model appear\ulcorner 3. When the causes of the scale error propagation are found, is the evaluation standard determined normally\ulcorner 4. What degree of influence is there form the constant errors\ulcorner I have done several experiments using the simulation method technique to solve the complicated error propgation of aerial triangulation which is the effective means to research the relations between cause and effect. In this paper, the studies have concentrated on the following points of simulation experiments. (1) The first part descries how we can produce the soft program of the simulation experiment. (2) The second part is the method propagating the errors in the simulation models and the kinds of errors. (3) The final part is the most important; that is the analyzing and evaluation of control during actual work. From the above-mentioned points, it is said that these studies are a very important development in the field of controlling and managing aerial photogrammetry and especially in the case of error propagation, we can clearly find the causes of the errors and steps and parts of errors generated when we use these techniques.

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청소년의 건강증진 행위 (Health promoting behavior of adolescents)

  • 소희영;김현리
    • 한국보건간호학회지
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    • 제12권2호
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    • pp.107-121
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    • 1998
  • The purpose of this study was to test the revised Health Promotion Model of Pender and to determine the factors to promote health behavior for adolescents' smoking behavior. The subjects of the study was 783 boys of 4 high school students. among 39. schools locating in Daejeon metropolitan city. The data was collected from July 1st to 15th. 1997 by school health nurse The research tool were HPLP of Walker. Pender. General self-efficacy scale of Sherer. control scale was measured by subconcept of hardiness scale of Pollock. and perceived barrier. perceived benefit. activity-related-affect tool were made by researcher via literature review The data were analyzed by SAS program using frequency. t-test. ANOVA. Schefee test. regression. The results were as follows 1. The mean of total health promoting behavior was $2.27\pm.35$. Among sub domain of health promoting behavior, the highest score was interpersonal support$(2.72\pm.60)$. and the lowest was health responsibility $(1.58\pm.44)$. 2. There were statistically significant difference in total health promoting behavior according to religion. parenting style. school performance. girl friend. father's smoking of individual characteristics. 3. The socioeconomic status. smoking, parent pattern. family structure of individual characteristics and experience domain associated with perceived benefit. perceived barrier. activity-related affect. interpersonal influence of behavior-specific cognition and affect domain. The perceived barrier. self-efficacy. girl friend and father's smoking of interpersonal influence. and control explained $25.8\%$ of variance of health promoting behavior. From above results school health nurse has to emphasize on health responsibility for health promotion of adolescent. But they couldn't intervene for parent pattern. socioeconomic status. family structure of individual characteristics and experience domain. it could be possible for school health nurse to promote health of adolescents through improving perceived barrier. also develop program to increase self-efficacy and through parent health class for fathers. Above results point to the importance of including parents in smoking prevention effort targeting adolescents. Because increasing control also promotes health of adolescents. it should be studied further about the specific measure. To verify the variables for increasing the fitness of health promoting model. it needs further replication of the research.

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Optimization of drag reduction effect of air lubrication for a tanker model

  • Park, Seong Hyeon;Lee, Inwon
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제10권4호
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    • pp.427-438
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    • 2018
  • The reduction of $CO_2$ emissions has been a key target in the marine industry since the IMO's MEPC published its findings in 2009. Air lubrication method is one of the mature technologies for commercialization to reduce the frictional resistance and enhance fuel efficiency of ships. Air layer is formed by the coalescence of the injected air bubbles beyond a certain air flow rate. In this study, a model ship (${\lambda}=33.33$) of a 50,000 ton medium range tanker is equipped with an air lubrication system. The experiments were conducted in the 100 m long towing tank facility at the Pusan National University. By selecting optimal air injector configuration and distribution ratio between two injectors, the total resistance of model $R_{TM}$ was able to be reduced down to 18.1% in the model scale. Key issue was found to suppress the sideway leakage of injected air by appropriate injection parameters.

Simulation of Quantum Effects in the Nano-scale Semiconductor Device

  • Jin, Seong-Hoon;Park, Young-June;Min, Hong-Shick
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제4권1호
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    • pp.32-40
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    • 2004
  • An extension of the density-gradient model to include the non-local transport effect is presented. The governing equations can be derived from the first three moments of the Wigner distribution function with some approximations. A new nonlinear discretization scheme is applied to the model to reduce the discretization error. We also developed a new boundary condition for the $Si/SiO_2$ interface that includes the electron wavefunction penetration into the oxide to obtain more accurate C-V characteristics. We report the simulation results of a 25-nm metal-oxide-semiconductor field-effect transistor (MOSFET) device.