• 대한의용생체공학회:의공학회지
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• 제41권2호
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• pp.84-93
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• 2020

Despite of a lot of studies about proprioception tests, there are little study results to investigate the relationship between the functional movement and proprioception level. In this study, we tried to perform quantitative analysis for the effect of ankle joint proprioception level on the one leg standing postural control ability. Nine healthy people volunteered for this study. Force and position aspects of proprioception were evaluated using the electromyography system (EMG) and mobile clinometer application, respectively. The center of pressure (COP) trajectories, measured by a pressure mat sensor, were used for quantitative analysis of balance for each subject. We computed indices and errors of force and position aspects of proprioception from the EMG and ankle angle. Mean velocity of total and anterior-posterior direction (Vm and Vm_ap), root mean squared distance in anterior-posterior direction (RDap), travel length (L), and area (A) of COP trajectories were also calculated as indices of postural control ability of subjects. Two aspects of proprioception showed the low correlation from each other as previous studies. However, the EMG error of gastrocnemius lateral activation showed a high correlation coefficient with COP variables such as Vm (ρ=0.817, p=0.007), Vm_ap (ρ=0.883, p=0.002), RDap (ρ=0.854, p=0.003), L (ρ=0.817, 0.007) and A (ρ=0.700, p=0.036). Within our knowledge, this is almost the first study that investigated the relationship between proprioception level and functional movement. These study results could support that the ankle joint proprioception facilitation exercise would have positive effects on functional balance rehabilitation interventions.

• 한국대기환경학회지
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• 제29권6호
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• pp.745-756
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• 2013

The purpose of this study is to evaluate representativeness of fuel-based emission factors. Twelve light-duty diesel vehicles which meet Euro-3 to 5 legislative emission limits were selected for emission tests. Second-by-second modal emission rates of vehicles were measured on a standard laboratory chassis dynamometer system. An off-cycle driving cycle was developed as a representative Korean real-world on-road driving cycle. Fuel-based emission factors were developed for short trip segments that involved in the selected driving cycle. Each segment was defined to have unit travel distance, which is 1 km, and characterized by its average speed and Relative Positive Acceleration (RPA). Fuel-based $NO_x$ emission factors demonstrate relatively good representativeness in terms of vehicle operation conditions. $NO_x$ emission factors are estimated to be within ${\pm}20%$ of area-wide emission factor under more than 40% of total driving situations. This result implies that the fuel-based $NO_x$ emission factor could be practically implemented into the on-road emission management strategies, such as a remote sensing device (RSD). High emitting vehicles as well as high emitting operating conditions heavily affect on the mean values and distributions of CO and THC emission factors. Few high emitting conditions are pulling up the mean value and biasing the distributions, which weaken representativeness of fuel-based CO and THC emission factors.

• 한국조경학회지
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• 제22권3호
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• pp.151-162
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• 1994

This is a comparative study on the use pattern and satisfaction of skiers between the suburban skiing ground and the resort one. The purpose of this study is to provide basic data for the planning and the management of skiing ground. The sites of case study are Yong Pyung Ski Resort (Resort type) and Bears Town(Suburban type). Data were collected from questionaire. A total of 420 questionaires were completed. And data were subjected to following analysis: First, the descriptive statistics(mean, chi-square analysis etc.) were used to compare the characteristics of the users and the use pattern of two sites. Second, factor analysis was utilized to reduce 22 satisfaction items into the smaller number of factors. Third, regression analysis was used to find the factors affecting users' overall satisfaction in each skiing ground. The findings of this study are as follows: First, it was proved that the characteristics of users between tow sites were different in terms of age, income, and skill level. Second, it was proved that the use pattern between two sites were different in terms of travel distance from home, traffic mode, length of stay, accommodation type, and the money spent per day. Third, By a principal component factor analysis several factors of satisfaction are found: In physical terms, they are 'slope and life facilities', 'recreation and lodge facilities', 'accessibility', 'crowding', and 'landscape'. In psychological terms, they are 'skiing skills and thrills', and 'relaxation and freedom'. Forth, As the result of the stepwise regression analysis, it was yielded that 'relaxation/and freedom' was most important factor to predict the overall satisfaction in both skiing ground. And it was proved that not only physical factors but also phychological(need gratifying) factors were important sources of the satisfaction.

• 한국시뮬레이션학회논문지
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• 제27권2호
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• pp.71-81
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• 2018

조선소의 지게차는 작업 특성상 무거운 물건을 상/하차하거나 이송하는 작업이 빈번하다. 작업은 동적이며 시간대별로 생성 비율이 다르다. 특히 오전과 오후 업무시간 직후에 작업 발생 비율이 높은 경향을 보인다. 이러한 상/하차 작업과 이송작업의 무게는 매번 다르며, 활용되는 지게차 역시 작업 가능한 허용무게의 제약이 있다. 본 연구에서는 지게차의 원활한 운영을 위해 최소 비용할당을 사용한 최근린 배차 규칙 알고리즘을 제안한다. 제시된 알고리즘은 다양한 종류의 지게차와 다수의 작업을 동시에 고려하여 배차를 결정하며, 지게차 종류에 따른 작업 불가능을 고려하기 위해 가상 지게차와 가상 작업을 생성하는 방법을 제안한다. 그리고 차량의 상태를 고려하여 체계적으로 지게차를 선택하는 방법도 함께 제시한다. 성능지표는 평균 공차이동거리와 평균 작업대기시간으로 한다. 성능비교를 위해 조선소의 지게차 운영방식을 모델링한 우선순위 규칙을 비교 대상으로 한다. 시뮬레이션을 통해 제시한 알고리즘의 우수성을 확인한다.

• 한국융합학회논문지
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• 제11권7호
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• pp.169-180
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• 2020

본 연구는 국가 간 이동이 발생한 지오트윗 사용자를 이동거리평균과 이동거리표준편차에 따라 그룹화하여, 국가 간 이동과 자국 내 이동에서 나타나는 특징을 발견하고 연구의 의의를 찾고자 하였다. 데이터마트를 구축 후 국가 간 이동과 자국 내 이동이 발생한 지오트윗을 분리하였고, 해버사인공식을 이용해 사용자의 이동거리를 측정하였다. 국가 간 이동 집단에서는 동일한 언어를 사용하며 생활방식이 비슷한 국가 사이에서 많이 이동하였고, 자국 내 이동에서는 인프라가 잘 구축된 선진국 위주의 국가에서 많은 이동이 발생하였다. 본 연구는 사용자별 이동거리를 계산하여 공통된 특징을 도출하고자 하였으며, 사용자의 이동거리 특성에 따라 그룹화하였다. 본 연구에서 분석한 21개국은 국가별 경제력이나 나이, 직업 등에서 차이가 커 많은 제반 사항이 고려되어야 정밀한 분석이 가능할 것이다. 향후에는 현실적인 사항을 추가한 연구가 진행되어야 할 것이다.

• 근관절건강학회지
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• 제1권1호
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• pp.88-96
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• 1994

Treatment for the arthritic is mostly on the out-patient basis. The present rheumatologists practicing in Korea do not cover the total number of the patients. Also patients with arthritis need medical treatment for long period of time. Therefore, the number of patients waiting for the treatment is huge in number. This vicious cycle need to be broken in some way. Purpose of this study is to identify the need for home care of the arthritic patients. Nineteen hundred and sixty two subjects were interviewed in one hospital for one month. The following findings were observed : 1. The rates for demanding home care were from 60% to 100% depending on the areas. 2. Reasons for no need of home care were mainly credibility and short distance from the hospital. 3. Time spent for one way transportation was more than 3.3 hours except from Seoul and Kyungki area. The longer they spend time for transportation, the more they want home care services. 4. The number of patients who asked other persons to travel for prescription was 446(22.73%) and average number was 3.26 per year in those 446 cases. 5. Average expenses for transportation and other cost for each time of hospital visit were 21,073won ranged from 8,373 won to 132,571 won. The more spend money for visiting the hospital, the more they want home care services. In order to reduce the physical and economical burden of the arthritic patients living in remote areas, hospital-based home care services are justified on the bases of patients' demand and legislative support.

• 한국대기환경학회지
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• 제28권1호
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• pp.94-104
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• 2012

The purpose of this research is to quantify the compliance of on-road emission from a light duty diesel vehicle, based on a comparison to emission regulation standard. $NO_x$, CO and THC emissions were measured using a portable device on a selected real-world driving route with a length of approximately 22 km. On-road measurements were repeated by 10 times on a same route to reflect variability in traffic conditions. A test route was divided into 22 road links with length of 1 km to analyze emission results with higher spatial resolution. The average emissions of $NO_x$, CO and THC over total travel distance, which is approximately 220 km, were quantified to be in compliance with emission regulation standards. Under higher spatial resolution, $NO_x$ concentration exceeded a standard in 92 links out of 220 links. The extended time in stop period and the stop-and-go driving cycle were identified as two important reasons for increased $NO_x$ emissions in observed cases. Heavy traffics showed higher $NO_x$ emissions than free flow. These results indicate that the real-world vehicle emissions might exceed the compliance level associate with traffic conditions. Another interesting observation of this research is that the on-road emission characteristics can be independent to the average speed of road links with higher spatial resolution. Variability in on-road emission might not be fully described by solely relying on an average speed, because variability in traffic conditions and road conditions can influence on real-world vehicle emissions.

• 농촌계획
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• 제19권4호
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• pp.137-147
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• 2013

Most of livestock houses are concentrated in certain area with mass rearing system resulting in rapid spread of infectious diseases such as HPAI (highly pathogenic avian influenza). The livestock-related vehicles which frequently travel between farms could be a major factor for disease spread by means of transmission of airborne aerosol including pathogens. This study was focused on the quantitative measurement of aerosol concentration by field experiment while vehicles were passing through the road. The TSP (total suspended particle) and PM10 (particle matter) were measured using air sampler with teflon filter installed downward the road with consideration of weather forecast and the direction of road. And aerosol spectrometer and video recorders were also used to measure the real-time distribution of aerosol concentration by its size. The results showed that PM2.5 was not considerable for transmission of airborne aerosol from the livestock-related vehicle. The mass generated from the road during the vehicle movement was measured and calculated to 241.4 ${\mu}g/m^3$ by means of the difference between TSP and PM2.5. The dispersion distance was predicted by 79.6 m from the trend curve.

• 대한교통학회지
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• 제27권6호
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• pp.45-53
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• 2009

서울시의 버스체계개편 시행 후 약 4년이 지난 현재 대중교통 이용승객의 증가에도 불구하고 서울시의 재정부담은 크게 개선되지 못하였다. 이에 서울시는 버스의 경쟁력을 강화하고 효율성을 제고하기 위한 정책들을 수립할 계획이며, 이러한 정책의 효과를 객관적으로 평가하기 위해서는 버스수단 경쟁력의 기반이 되는 노선의 효율성 추정과 이에 영향을 미치는 요인들의 분석이 요구된다. 본 연구에서는 2008년 서울시 간선버스 노선의 자료와 DEA 모형의 하나인 BCC 모형을 이용하여 각 노선의 효율성을 추정하였다. 효율성 추정시 각 노선은 차량대수, 노선거리, 정류장개수, 배차간격, 운영비를 투입하여 승객수와 수익금을 산출하는 것으로 가정하였다. 투입지향 BCC 모형으로 분석한 결과, 평가노선 18개 중 규모수익불변(CRS)인 노선은 총 2개이며, 나머지 16개 노선은 규모수익체증(IRS)인 노선으로 분석되었다. 또한 분석에 사용된 요소들이 효율성 점수에 미치는 영향을 파악하기 위하여 토빗회귀분석을 수행한 결과, 현재 간선버스에 가장 큰 영향을 미치는 변수는 배차간격인 것으로 분석되었다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2011년도 춘계학술대회
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• pp.218-219
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• 2011

본 논문은 컨테이너 운송을 위한 AGV(Automated Guided Vehicle) 배차 전략을 대상으로 한다. AGV 배차 문제는 안벽 크레인의 대기 시간과 AGV의 주행 거리를 최소화하도록 AGV에 작업을 할당하는 것이 목표이다. 터미널 환경의 동적인 특성으로 인해 계획 결과의 정확한 예측이 어렵고 수정이 빈번하기 때문에 실무에서는 의사결정 시간이 짧은 단순 규칙 기반 배차가 많이 쓰인다. 그러나 단순 규칙 기반 배차는 근시안적 특성으로 인해 배차의 다양한 성능 지표를 만족시키지 못하는 한계가 있으며 이를 극복하기 위해 본 논문에서는 복수 규칙 기반의 배차 전략을 제안한다. 복수 휴리스틱 기반 배차 전략은 여러 규칙의 가중합으로 구성되며 규칙 사이의 가중치를 최적화하기 위해 다목적 진화 알고리즘을 적용하였다. 시뮬레이션 실험을 통해 제안 방안이 기존 단일 규칙 기반 배차에 비해 더 좋은 성능을 보임을 확인하였다.