• Korean Journal of Occupational Therapy
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• v.26 no.4
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• pp.127-143
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• 2018

Objective : The purpose of this study was to compare with the effects of driving simulator and Dynavision training after stroke through the test of cognitive ability and driving performance. Methods : Twenty-one stroke patients were randomly classified to the driving simulator training group (N=11) and Dynavision training group (N=10), and were carried out respectively training for 15 times. The driving performances was measured by the driving simulator test, and cognitive-perceptive abilities was measured by the DriveABLE Cognitive Assessment Tool, Trail Making Test-A, Trail Making Test-B and Mini Mental State Examination-K. Results : The driving simulator training group showed significant changes in all cognitive tests and most of driving performances. The Dynavision training group also showed significant changes in all cognitive tests except for Trail Making Test-A and some driving performances. The significant differences on both groups were found regarding the estimated degree of results on the on-road evaluation, the number of off road accidents and collisions. In addition, the causal influence of the two training methods on these variables was analyzed to be more than 20%. Conclusion : The driving simulator and Dynavision training were found to be effective intervention in the driving rehabilitation after stroke. In particular, it was confirmed that the driving simulator is an effective training to improve overall driving ability of stroke patients. In addition, the difference in training effect between the two training methods was found to be more than 20%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.445-454
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• 2022

Ice accretion on the aircraft components, such as wings, fuselage, and empennage, can occur when the aircraft encounters a cloud zone with high humidity and low temperature. The prevention of ice accretion is important because it causes a decrease in the aerodynamic performance and flight stability, thus leading to fatal safety problems. In this study, a shape design optimization of a multi-element airfoil is performed to minimize the amount of ice accretion on the high-lift device including leading-edge slat, main element, and trailing-edge flap. The design optimization framework proposed in this paper consists of four major parts: air flow, droplet impingement and ice accretion simulations and gradient-free optimization algorithm. Reynolds-averaged Navier-Stokes (RANS) simulation is used to predict the aerodynamic performance and flow field around the multi-element airfoil at the angle of attack 8°. Droplet impingement and ice accretion simulations are conducted using the multi-physics computational analysis tool. The objective function is to minimize the total mass of ice accretion and the design variables are the deflection angle, gap, and overhang of the flap and slat. Kriging surrogate model is used to construct the response surface, providing rapid approximations of time-consuming function evaluation, and genetic algorithm is employed to find the optimal solution. As a result of optimization, the total mass of ice accretion on the optimized multielement airfoil is reduced by about 8% compared to the baseline configuration.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.770-778
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• 2023

Purpose: In order to reduce forklift industrial accidents, it is necessary to classify them into institutional, technical, and educational factors and conduct research on whether each factor affects disaster reduction. Method: Descriptive statistical analysis, validity analysis, reliability analysis, and multiple regression analysis were conducted using SPSS 18 program based on an offline questionnaire based on a 5-point Likert scale. Result: As a result of multiple regression analysis, it was found that institutional, technical, and educational factors, which are independent variables for disaster reduction, explain about 62.5% of the variance in disaster prevention, which is the dependent variable. The regression model verification was found to be statistically significant with F=118.775 and significance probability p<0.01. Conclusion: First, there is a need to prevent disasters by including electric forklifts weighing less than 3 tons in the inspection system. Second, there is a need to make it mandatory to install front and rear cameras and forklift line beams to prevent forklift collision disasters. Third, there is a need to conduct special training related to forklifts every year, and drivers and nearby workers need to be included in the special training for forklifts.

• Korea journal of population studies
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• v.19 no.2
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• pp.175-205
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• 1996

The purpose of this study was to find the distribution of the variables on the quality of life and the determinants of the sexual attitude and behavior of the unmarried female workers. This study was surveyed to the 306 unmarried women who worked in the small and medium scale industries in Kyungin area and analyzed the respondent's knowledge of sex, sexual behavior, health behavior, health status, satisfaction of working condition and recognition of working environment. The result of this study could be summarized as follows: The respondent's age are mostly early of twenties and their education level are high school and more. They recognize that their health condition is not so good but they hardly try to improve health condition. They think that their working condition are mostly unsatisfied and they also believe that they expose themselves to the toxic working environment. Although their knowledge of sex are low they have few chances for the education of sex and family planning. Their attitude of premarital sex are conservertive but the rate of approval of living together before marriage are high and the rate of premarital sex is around 15 percent. The premarital sex behavior are positively related with family size, living condition, knowledge of sex and working period but the sex experiences are negatively related with working period and knowledge of sex. As a result we suggest that the sex education and consultative program are necessary for improving the quality of life of the unmarried working women in small and medium scale industries.

• Journal of Korea Technology Innovation Society
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• v.20 no.1
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• pp.127-152
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• 2017

China's utility model as a supplement to the invention patent, has short application duration, fast authorized speed, and has the same exclusive rights with patents, so companies can quickly dominate the market. But the utility model does not need to carry out substantive examination, so has lower stability, high frequency of invalid to accepted, so compare with the invention patent, difficult to be protected. In order to actively encourage the small and medium-sized enterprises to promote their inventions, and protect domestic patents, China established a protection policy of patent evaluation report for the utility model rights, especially the patent evaluation report can be used as evidence in a patent infringement trial, to provide judicial remedies for utility model patentee and the party of patent disputes. Many experts believe that the establishment of patent evaluation report system can improve the stability of the utility model patent right, and when the defendant request for invalidation of the patent right in the defense period, if there is no novelty, creativity lost or no other reason has not led to the stability of patent right given in a patent evaluation report of the utility model patents, the court may not suspend the trial, without having to wait for the Patent Reexamination Board makes the patent invalid declaration decisions, can improve the efficiency of the judicial process, accelerate the patentee's time. However, in practical patent infringement, the patent evaluation report system and invalidation system are in conflict. In this paper, through the analysis of the current China utility model system and compared with the South Korean utility model system, review the role and character of the patent evaluation report system, and through the actual cases of the utility model patent infringement litigation, analysis possible variates from the decision of patent evaluation report, to find out the reason of the patent evaluation report system being in conflict with the invalidation system, and research on the effectiveness for protecting Utility Model with China's Patent Evaluation Report.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4675-4681
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• 2014

This study examined the $H_2S$ removal characteristics, such as breakthrough time, adsorption capacity, and adsorption rate of adsorbents between Zeolite 3A and DETOX in terms of the $H_2S$ inflow concentration and adsorption temperature. The adsorption capacity of Zeolite 3A increased with increasing mass flow rate of hydrogen sulfide($H_2S$) inflow, but the breakthrough time decreased. On the other hand, both the adsorption capacity and breakthrough time of DETOX decreased with increasing mass flow rate of $H_2S$ inflow. The adsorption capacity and breakthrough time of Zeolite 3A decreased with increasing adsorption temperature but those of DETOX increased. The adsorption capacity of DETOX was higher than that of Zeolite 3A by a factor of 2.5 - 16.4 because the collision frequency that overcomes the activation energy barrier increased with increasing adsorption temperature. For Zeolite 3A and DETOX, the adsorption rate of $H_2S$ increased with increasing mass flow rate of $H_2S$ inflow and adsorption temperature. The adsorption rate of $H_2S$ for Zeolite 3A was 4 times as much as that for DETOX. For the removal of $H_2S$ in biogas, DETOX had an advantage over Zeolite 3A because DETOX had a much longer breakthrough time and greater adsorption capacity in the temperature range of 308~318K than Zeolite 3A.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.249.2-249.2
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• 2010

최근의 고유가와 환경오염에 대한 대응 수단으로 수송용 바이오연료의 보급에 대한 관심이 세계적으로 높아지고 있다. 이 중 바이오디젤은 동식물성 기름으로부터 메탄올과의 전이에스테르화 반응에 의해 생산되는 경유대체 연료로서 환경 친화성과 지속가능성이 인정됨에 따라 그 생산량이 급격히 증가하고 있다. 바이오디젤의 생산량이 증가함에 따라 대두유, 유채유, 팜유 등의 원료유 가격 상승 및 수급 불안정 문제가 대두되고 있으며 식량자원과의 충돌 문제도 발생되고 있다. 이를 해결하기 위한 방안으로 유리지방산 함량이 높은 저가유지 자원(폐식용유, 폐돈지, 폐우지, soapstock, trapped grease)을 이용한 공정 개발 연구가 활발히 진행되고 있다. 본 연구에서는 비활용되고 있는 해외 열대작물 열매씨앗에서 착유한 식물성 오일의 바이오디젤 원료유로서의 사용 가능성을 검토하였다. 열대작물 오일의 물성 분석 결과 고형물, 수분, 인, 유리지방산 함량이 대두원유보다 매우 높게 나타났다. 오일 중의 인지질은 바이오디젤 제조 반응후 에스테르와 글리세린의 층분리를 방해하여 공정 효율을 감소시키고 유리지방산은 염기촉매와 결합하여 지방산염을 생성해 생산수율을 감소시키는 문제를 일으킨다. 고형물과 수분은 여과와 감압증발에 의해 쉽게 제거가 가능하였다. 15~20%의 유리지방산 함유 열대작물 오일의 전처리를 위해 균질계 산촉매와 비균질 고체 산촉매를 이용해 에스테르화 반응 효율을 조사한 결과 황산이 가장 높은 효율을 보였다. 반응표면분석법(Response Surface Method, RSM)을 적용해 메탄올과 촉매량의 2변수 에스테르화반응 최적화를 수행한 결과 메탄올 26%, 촉매 0.98%로 최적 조건이 도출되었으며 초기 산가 33mgKOH/g에서 0.98mgKOH/g으로 감소됨을 확인하였다. 전처리 정제한 오일의 물성분석 결과 고형물 0.1%, 수분 0.10%, 산가 1.0mgKOH/g, 인함량 20ppm 이하로 바람직한 원료유가 생산됨을 알 수 있었다. 제조된 원료유를 이용해 전이에스테르화 반응 최적화 실험을 RSM에 근거하여 진행한 결과 KOH 0.8%, 메탄올:오일 몰비 6.2:1, 반응온도 $60^{\circ}C$, 교반속도 200rpm, 반응시간 30분으로 나타났으며 증류 정제전 97.3%, 증류후 100.0%의 바이오디젤을 생산 할 수 있었다. 열대작물 오일의 전처리 공정은 메탄올을 과잉양으로 사용함으로 효과적인 알콜 회수 공정이 중요하다. 전처리 후 층분리를 통해 회수되는 메탄올 중의 수분함량은 2%~7%로서 이를 전처리 반응에 재사용하기 위해서는 0.3%이하의 수분함량으로 정제가 필요하다. 본 연구에서는 고가의 증류탑 형태가 아닌 단증류방식으로 2단계 내지 3단계로 0.3% 수분의 메탄올 회수 조건을 도출하였으며 파일롯 공정 설계를 진행하고 있다. 이로서 본 연구의 열대작물 오일은 저가로 충분한 물량의 확보가 가능하다면 바이오디젤 원료 자원으로서 큰 활용가치가 있는 것으로 판단된다.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.4
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• pp.21-32
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• 2004

A Seismic analysis procedure of bi-directional brideg motions is developed by using mechanical bridge model. A three-dimensional mechanical model can consider major phenomena under bi-directional seismic excitations, such as nonlinear pier motion under biaxial bending, pounding and bearing damage due to the rotaion of the superstructure, etc. The analyses utilizing the uni-directional and the bi-directional bridge model for the 3-span simply supported bridge are then performed. The seismic responses in two cases are examined and compared by investigating the relative displacements of each superstructure to both ground and adjacent superstructures and the restoring forces of RC pier. The analysis using either the uni-directional model or bi-directional model is acceptable for estimating the displacement responses of a bridge, but the bi-directional analysis is found to give more conservative results for resisting forces of RC piers. To make general conclusions, therefore, the analysis using the bi-directional bridge model should be performed in evaluating the seismic safety of bridges.

• Tribology and Lubricants
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• v.12 no.1
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• pp.1-5
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• 1996

자성유체는 자연에서 추출한 것이 아니라 자화성(Magnetizability)과 유도성(Flowability)을 동시에 갖도록 합성한 특수액체이다. 자성유체는 1960년대 중반에 미국의 NASA에서 처음 개발된 이후로 윤활, 밀봉, 감쇄, 의료 등의 분야에서 응용연구가 많이 진행되었기 때문에 고도의 정밀도를 요하는 항공, 우주산업, 컴퓨터와 반도체 분야 등에서 실용화가 크게 진전되고 있다. 특수물질일 자성유체는 전기적으로 도체인 10nm 정도의 미세한 자기입자(Magnetic particles)에 코팅을 한 후, 이것을 물, 탄화수소, 플루오르카본, 에스터 등의 매개유체(Carrier Fluids)에 혼합시켜서 콜로이드 상태로 사용하게 된다. 자성유체는 미세한 자기입자들이 매개유체내에서 서로 충돌하면서 반발력을 발생시켜서 상호간에 늘 콜로이드 상태를 유지하고 있으며, 이 특수유체가 자기장의 영향을 받게 되면 점도가 증가하면서 특이한 성질을 갖게 된다. 상대 접촉 운동면에 경계마찰이나 혼합마찰을 하게 되면 윤활상태는 비교적 나쁘다. 이러한 마찰지역에 콜로이드상의 자성유체 윤활제를 공급하면 기존의 윤활제에 비하여 대단히 효과적으로 윤활을 할 수 있게 된다. 그러나 자성유체 윤활제가 마찰부위에 원활하게 공급하기 위해서는 미끄럼 마찰부에서 자기장을 잘 형성시킬 수 있는 도체이어야 하기 때문에 특별한 윤활 시스템 설계가 제시되어야 한다. 자성유체 윤활제는 합성으로 제조된 특수물질로 여러가지 장점을 갖고는 있으나 기존 윤활유와의 적합성, 마찰열, 밀봉압력 등의 조건에서 제한적으로 사용될 수 밖에 없으므로 항공, 우주 산업이나 석유 화학분야와 같이 특수 환경에서만 사용되고, 또한 기존의 광유계 윤활제에 비하여 대단히 고가하는 문제점을 갖고 있다. 그러나 윤활 마찰면의 다양화와 가혹한 사용조건은 자성유체 윤활제의 연구개발 필요성을 크게 증대시키고 있다.xed Effects Model)을 결정하고, 각각에 해당하는 통계모형을 구축하였다. 이 결과 (1) 업종 및 기업규모별로 그룹간에 유의한 특성이 발견되었으며, (2) R&D 및 광고투자는 기업의 시장성과를 설명하는 중요한 변수이나, (3) R&D 투자의 경우는 광고에 비해 불확실성이 존재하는 것으로 나타났고, (4) 수리모형에서 도출된 한계원리가 통계모형에서도 유효한 것으로 드러났다.등을 토대로 한 10대 산업을 육성하기 위하여 과학기술부는 기술수요조사를 바탕으로 49개 주요기술을 도출하여, 과학기술 일류 국가 실현, 국민소득 2만불 달성이라는 국가적 슬로건을 내걸고 “차세대 성장동력” 창출을 위한 범정부차원의 기획과 연구비의 집중투자를 추진하고 있다.달성하기 위해서는 종합류류 전산망의 시급한 구축과 함께 화물차의 적재율을 높이고 공차율을 낮출 수 있는 운송체계의 수립이 필요한 것으로 판단된다. 그라나 이러한 화물전용차선의 효과는 단기적인 치유책일 수밖에 없기 때문에 물류유통 시설의 확충을 위한 사회간접자본의 구축을 서둘러 시행하여야 할 것이다.으로 처리한 Machine oil, Phenthoate EC 및 Trichlorfon WP는 비교적 약효가 낮았다.>$^{\circ}$E/$\leq$30$^{\circ}$NW 단열군이 연구지역 내에서 지하수 유동성이 가장 높은 단열군으로 추정된다. 이러한 사실은 3개 시추공을 대상으로 실시한 시추공 내 물리검층과 정압주입시험에서도 확인된다.. It was resulted from increase of weight of single cocoon. "Manta"2.5ppm produced 22.2kg of cocoon. It is equal to 9% increase in index, as compared to that of control. In case

• Archives of design research
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• v.19 no.5 s.67
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• pp.5-16
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• 2006

The purpose of this research is to bring to the center of focus, the ad creativity, which in turn can generate the highest advertising effects. The study excludes external factors such as personal relationships, academic network and lobbying powers which were prevalent in the Korean situation. A transformational leader can influence charisma, inspiration, intellectual stimulation, individual consideration and performance goal. As the result of this study shows, the core competence that a C.D. may always want to possess at present as well as in the future is to "motivate inspiration". Charisma may be an ability currently in need but this may not necessarily be so in the future. It may be predicted that a softer quality, which is knowledge-based, that provides intellectual stimulation may be a more valued characteristic. It has been suggested that in the increasingly diversifying society of the future, charisma may be a barrier to enhancing creativity. In times of uncertainty and ambiguity, innovative ideas bring economic rewards (Cockayne, 2004). There may be conflicts of views and opinions between individuals and organizations. Turning these into positive outcome to produce innovative ideas, may be an area of further study. However, there must have been studies where informal networking has produced innovative ideas. Therefore, a transformational leader of an organization needs to investigate the dynamics of informal networking within his team.