• 한국가정과교육학회지
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• 제20권4호
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• pp.59-75
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• 2008

본 연구는 청소년의 노년기 주생활 교육 실태 및 교육 필요도를 파악하여 개정 가정 교육과정 주생활영역에서의 교과서 개발 연구와 교사의 교수 시 도움을 주고자 하였다. 연구결과, 중학교 때 배웠던 노년기 주생활 수업이 이론 위주이고 교육내용이 흥미롭지 않아 상당수가 불만족하므로 학습자들이 실습과 체험활동 등을 경험할 수 있는 교육내용과 다양한 수업방식이 필요하겠다. 청소년은 노년기 주생활 교육내용으로 노인을 배려한 공간계획 요소(안전성, 관리, 실내 환경), 노년 주거계획 전반, 노인복지 서비스를 필요로 하였고, 3세대 가족 주거와 노인전용주택의 필요도는 상대적으로 낮았다. 이러한 교육내용은 성별, 거주면적, 가정소득, 출신 중학교 학교형태, 현 주택 거주 년 수의 일부 관련 변인에 따라 차이가 있었다. 따라서 2007년 개정 교육과정의 교과서에서는 필요도가 높은 교육내용을 적절한 단원에 포함시키도록 한다. 현행 7차 교육과정의 노년기 주생활 교육내용은 교과서별로 편차가 크므로 교과서 집필 시는 노년기 주생활 교육내용이 골고루 포함될 수 있도록 고려한다. 아울러 교사의 교수 시는 특성 변인의 차이를 감안하여 교육내용을 구성할 필요가 있겠다. 개정 교육과정에서는 교수.학습방법으로 학생들의 체험적인 활동을 중시하고, 지역사회와 밀접한 관계를 가지도록 권장하므로 현재의 장애체험 교육활동의 범위를 확장시켜 노인체험활동을 포함할 수 있도록 교육내용을 구성한다면 노년기 주생활 교육의 효과가 더 커질 것이므로 이를 위한 프로그램 개발도 요망된다.

• 감성과학
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• 제20권2호
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• pp.103-116
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• 2017

본 논문에서는 산업안전보건연구원에서 실시한 제 4차 근로환경조사(2014) 원시자료를 활용하여 서비스 종사자들의 고용형태에 따른 근로환경 실태와 근무사기에 관하여 연구하였다. 근로환경 실태는 업무자세, 감정노동, 업무 자율성으로 구성되어졌으며, 근로사기와 관련된 심리적 차원은 업무에서 느끼는 유능감, 직무만족, 사회적지지, 직무스트레스로 이루어졌다. 아울러 고용형태는 상용직, 임시직, 일용직 근로자를 중심으로 분류하여 분석하였다. 연구결과 상용직 근로자에 비해 임시직과 일용직 근로자들이 좀 더 열악한 환경에서 근무하는 것으로 밝혀졌다. 그러나 상용직 근로자들의 감성노동에 대한 질적 피로도는 더 높은 것으로 추정되었다 뿐만 아니라 근무환경과 근로사기 간에는 밀접한 상관관계가 있는 것으로 나타났다. 본 연구를 토대로 서비스업 종사자들이 가지는 실태와 문제점에 대해서 알 수 있었으며, 좀 더 나은 서비스가 되기 위해 근로자들의 근로환경과 근무사기를 높일 수 있는 방안들에 대한 모색들이 이루어질 수 있으리라 기대된다.

• 한국농공학회지
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• 제17권4호
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• pp.3962-3969
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• 1975

1. When the frame of the experimental apparatus was directly fixed on the platform, result from the spectrum density analysis showed that the generated vibration frequecy of the system was nearly-same as the system's own characteristic vibration frequency, 80Hz, in the case of the forcing vibration frequency was 7.5 to 22.5Hz. The reduction ratio of acceleration by balanced type model compare to non-balanced type one was 26.66 percent. 2. When the frame of experimental apparatus was fixed on the platform with putting a shock absorbing rubber between the frame and the platform, the generated vibration frequency of the system was same as forcing vibration frequency. When either frequency or the amplitude of the forcing vibration was increased, the acceleration ratio was increased too. The average reduction ratio was resulted 44.77 per cent. It was concluded that this method of acceleration measurement(the method using a shock absorbing rubber) was a reaonable method, because actual machine will work under such condition. As the vibration frequency and aptitude were increased, the absolute magnitude of acceleration was increased. 3. unbalanced rotating parts, and unbalanced moment of inertia of links were supposed to be causing factors of residual vibration in spite of using the balanced type oscillating mole drainer. This fact suggested that the attachment of the counter weight on the rotating parts which satisfy the condition mw$.$rw=m0e, was necessary. And also, it was expected that the shock absorbing effect could be improved by putting the shock absorbing materials between the moving parts and their supports.

• Journal of Biosystems Engineering
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• 제43권2호
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• pp.103-109
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• 2018

Purpose: This study has been conducted to develop a potato yield monitoring system, consisting of a segmentation algorithm to detect potatoes scattered on a soil surface and a counting system to count the number of potatoes and convert the data from two-dimensional images to masses. Methods: First, a segmentation algorithm was developed using top-hat filtering and processing a series of images, and its performance was evaluated in a stationary condition. Second, a counting system was developed to count the number of potatoes in a moving condition and calculate the mass of each using a mass estimation equation, where the volume of a potato was obtained from its two-dimensional image, and the potato density and a correction factor were obtained experimentally. Experiments were conducted to segment potatoes on a soil surface for different potato sizes. The counting system was tested 10 times for 20 randomly selected potatoes in a simulated field condition. Furthermore, the estimated total mass of the potatoes was compared with their actual mass. Results: For a $640{\times}480$ image size, it took 0.04 s for the segmentation algorithm to process one frame. The root mean squared deviation (RMSD) and average percentage error for the measured mass of potatoes using this counting system were 12.65 g and 7.13%, respectively, when the camera was stationary. The system performance while moving was the best in L1 (0.313 m/s), where the RMSD and percentage error were 6.92 g and 7.79%, respectively. For 20 newly prepared potatoes and 10 replication measurements, the counting system exhibited a percentage error in the mass estimation ranging from 10.17-13.24%. Conclusions: At a travel speed of 0.313 m/s, the average percentage error and standard deviation of the mass measurement using the counting system were 12.03% and 1.04%, respectively.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.19-25
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• 2008

Selective Catalytic Reduction is effective in the reduction of NOx emission. This research focused to evaluate the performance of a urea-SCR system and was conducted in two procedures. One is SCR reactor test using model gas in order to provide an optimal injection condition itself. In this step, some parametric study on emission temperature, space velocity, aspect ratio and the formation of urea spray were made by using flow visualization and Computation Fluid Dynamics techniques. The basic simulation results contributed in determining the layout for an actual engine test. The other is an engine performance and emission test. The urea injector was placed at the opposite direction of exhaust gases emitted into an exhaust duct and an optimal amount of a reducing agent is estimated accurately under different engine loads and speeds. Furthermore, the variation of NOx emission and applied amount of urea was investigated in terms of modes under the condition of with and without SCR, and other emissions such as PM, CO and NMHC were evaluated quantitatively as well. This research may provide fundamental data for the practical use of urea-SCR in future.

• 대한조선학회논문집
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• 제56권3호
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• pp.231-241
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• 2019

In this study, a simplified analysis method was developed to evaluate the fatigue damage of an ice-going ship under broken ice condition. The global ice load, which is essentially calculated at the design stage of the Arctic vessel, and the hull form information were used to estimate the local ice load acting on the outer-shell of the ship. The local ice load was applied to the finite element analysis model, and the Weibull parameters for the target fatigue point were derived. Finally, fatigue damage was evaluated by applying the S-N curve and the Palmgren-Miner rule. For the verification of the proposed method, numerical analyses using direct approach were performed for the same conditions. A numerical model that implements the interaction between ice and structure was introduced to verify the local ice load and the stress calculated from the proposed method. Finally, the fatigue analyses of the Baltic Sea for actual ice conditions were performed, and the results of the proposed method, the method using numerical analysis, and the LR method were compared.

• 한국전산유체공학회지
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• 제14권3호
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• pp.69-75
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• 2009

The objective of this study is to investigate the suitable design for a domestic Circulating water pump(CWP), which is used in cooling-water intakes for the unit 3 and 4 of Yeonggwang nuclear power plant. All the simulations are performed, using CFD method with a commercial code STAR-CCM+ version 3.02. After modeling a present design of the pump, the flow around the rotating blade was calculated by using quasi-static method and sliding mesh method with the almost same condition as an actual state. Based on fundamental simulations with various depth of sea water, the reference pressure for the boundary condition of the present study was decided. To verify the reliability of the calculation results, the suction flow rate of the data was compared with that of the experimental data. As a result of this comparison, it is confirmed that two results are fairly consistent. For the improvement of the suction flow rate, computational analysis was done by changing a flow channel and blade shapes. It is shown that the suction flow rate of the new pump was improved.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.960-965
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• 2014

Transmission loss of specimen is calculated by measuring energy of incident and transmission and using reverberant room of large size. But normal measurement of transmission loss has trouble because it is actually demanded that large area and specimen of certain size is satisfied with condition of diffused sound field. Especially, in case of mechanical component, interested frequency band is mid-frequency band between 500 ~ 2k Hz, and it is used to be available to minimize a reverberation chamber under conditions satisfying acoustic one because production of specimen for transmission loss measurement has limit. But, as in semi-reverberation room, it is difficult to satisfy condition of diffuse sound field and modification factor is applied to complement that. Correction factor when measuring transmission loss using semi-reverberation chamber is required accuracy because it works as main factor determining reliability of reuslts on transmission loss. In this study, it is analyzed that an effect on correction factor based on varying materials and sizes of specimens in order to deduction of it. Also It is confirmed that applied by elicited correction factor with actual railway vehicle's floor has reliability.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.232-238
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• 2009

The objective of this study is to investigate the suitable design for a domestic CWP pump, which is used in cooling-water intakes for the unit 3 and 4 of Yeonggwang nuclear power plant. All the simulations are performed, using CFD method with a commercial code STAR-CCM+ version 3.02. After modeling a present design of the pump, the flow around the rotating blade was calculated by using quasi-static method and sliding mesh method with the almost same condition as an actual state. Based on fundamental simulations with various depth of sea water, the reference pressure for the boundary condition of the present study was decided. To verify the reliability of the calculation results, the suction flow rate of the data was compared with that of the experimental data. As a result of this comparison, it is confirmed that two results are fairly consistent. For the improvement of the suction flow rate, computational analysis was done by changing a flow channel and blade shapes. It is shown that the suction flow rate of the new pump was improved.

• 소성∙가공
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• 제29권4호
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• pp.218-228
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• 2020

The prediction of final mass and optimized process conditions of injection molded products using Artificial Neural Network (ANN) were demonstrated. The ANN was modeled with 10 input parameters and one output parameter (mass). The input parameters, i.e.; melt temperature, mold temperature, injection speed, packing pressure, packing time, cooling time, back pressure, plastification speed, V/P switchover, and suck back were selected. To generate training data for the ANN model, 77 experiments based on the combination of orthogonal sampling and random sampling were performed. The collected training data were normalized to eliminate scale differences between factors to improve the prediction performance of the ANN model. Grid search and random search method were used to find the optimized hyper-parameter of the ANN model. After the training of ANN model, optimized process conditions that satisfied the target mass of 41.14 g were predicted. The predicted process conditions were verified through actual injection molding experiments. Through the verification, it was found that the average deviation in the optimized conditions was 0.15±0.07 g. This value confirms that our proposed procedure can successfully predict the optimized process conditions for the target mass of injection molded products.