• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.04a
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• pp.483-492
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• 1993

미래의 차의 선택사항이 될 여행정보시스템을 설치하여 그 성능의 인간공학적 조사를 수행하였다. 이 시스템을 실제로 GM자동차 Oldsmobile Toronado형 100대에 설치하여 사용자가 얼마나 쉽게, 빨리 그리고 안락하게 갈 수 있고, 어떻게 하면 좀 더 이것을 인간공학적으로 향상시킬수 있는 가를 연구하였다. 100대중 23대는 대학교에서 연구를 하고 나머지는 AAA회사의 회원권을 가진 지역사용자들에게 AAA회사와 AVIS회사를 통하여 대여를 하여 컴퓨터차(TravTek시스템)의 성능과 효율성을 시험하였다. 그 내용을 살펴보면, 차에 부착된 컴퓨터의 컬러화면으로 사용자에게 도로를 보여주고, 컴퓨터가 최단거리를 제시하여 운전자에게 컴퓨터음성과 화면으로 길을 안내한다. 그 파급효과로 도로 체증현상을 막고, 기름의 낭비도 절약하고, 밤에도 안전하게 운행할 수 있게 할 뿐만아니라 처음보는 거리라고 하더라도 컴퓨터가 안내하면서 목적지까지 무사히 도착할 수 있게 하여 준다. 이러한 시스템을 설치한 차를 타고 여행할 때, 여행자가 과연 얼마나 안락하게 여행할 수 있으며, 도로의 체증현상을 줄이고, 사고를 예방하며, 차의 설계와 목적이 인간공학적으로 합당한 가를 알아보고자 하는 연구이다. 인간공학적 평가 인자들은 (1) 운전자의 수행도, (2) 사용자 선호도, (3) 사용자 인식, (4) 운행정보등이다. 그리고 컴퓨터음성을 사용하였을 때와 사용하지 않았을 때의 두가지 경우와 (1) 움직이는 컴퓨터지도를 사용하였을 때 (2) 단순화한 도로안내를 사용하였을 때, (3) 컴퓨터 지도를 사용하지 않았을 경우(종이지도사용)에 관해 위의 4가지 인간공학적 인자들을 평가하고자 한다. 이 연구는 아직도 진행중이라 발표하고자 하는 논문역시 현재까지의 연구결과를 토대로 발표하는 것이므로 완전한 결론을 내릴 수는 없고, 진행과 정의내용과 토의사항과 잠정적인 결론을 제시하고자 한다. 의거한 작업순서 결정을 위해 우선 BB의 상한을 구하는 연구를 행했다. 이를 위해 우선 단일작업장에서 야기될 수 있는 모든 상황을 고려한 최적 작업순서 결정규칙을 연구했으며, 이의 증명을 위해 이 규칙에 의거했을 때의 보완작업량이 최소가 된다는 것을 밝혔다. 보완작업 계산의 효율성을 제고하기 위해 과부하(violation)개념을 도입하였으며, 작업유형이 증가된 상황에서도 과부하 개념이 보완작업량을 충분히 반영할 수 있음을 밝혔다. 본 연구에서 제시한 최적 작업순서 규칙에 의거했을 때 야기될 수 있는 여러가지 경우의 과부하를 모두 계산했다. 앞에서 개발된 단일작업량의 최적 작업순서 결정규칙을 이용하여 다작업장의 문제를 실험했다. 이 문제는 규모가 매우 크므로 Branch & Bound를 이용하였으며, 각 가지에서 과부하량이 최적인 경우만을 고려하는 휴리스틱을 택하여 실험자료를 이용하여 여러 회 반복실험을 행했다. 그리고 본 연구의 성과를 측정하기 위해 휴리스틱 기법시 소요되는 평균 CPU time 범위에서, 랜덤 작업순서에 따른 작업할당을 반복실험하여 이중 가장 좋은 해와 비교했다. 그러나 앞으로 다작업장 문제를 다룰 때, 각 작업장 작업순서들의 상관관계를 고려하여 보다 개선된 해를 구하기 위한 연구가 요구된다. 또한, 준비작업비용을 발생시키는 작업장의 작업순서결정에 대해서도 연구를 행하여, 보완작업비용과 준비비용을 고려한 GMMAL 작업순서문제를 해결하기 위한 연구가 수행되어야 할 것이다.로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.1-9
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• 2018

Visibility is very poor in tunnel fire because of confined space where the fire may easily lead to the mass casuality incident because of fast smoke spread. In this test, air curtain and the fan were installed at rescue station in a bid to make use of rescue station in safe way during the train fire in undersea tunnel and a full-scale fire test was conducted to identify the applicability of air curtain system. Air curtain system was installed at a real rescue station and the test was continued for 2 minutes till heptane which was used as fire source was completely burned out. When air curtain was working, difference in temperature between inside and outside the platform was $160^{\circ}C$ and carbon monoxide measured inside the platform was less than the case of no air curtain system by 160 ppm. Thus a full-scale fire test demonstrated that the air curtain system installed at rescue station in undersea tunnel was able to effectively block the heat and smoke generated from the fire.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.6
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• pp.367-378
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• 2006

A mobile phone has became as a payment tool in e-commerce and on-line banking areas. This trend of a payment system using various types of mobile devices is rapidly growing, especially in the Internet transaction and small-money payment. Hence, there will be a need to define its standard for secure and safe payment technology. In this thesis, we consider the service types of the current mobile payments and the authentication method, investigate the disadvantages, problems and their solutions for smart and secure payment. Also, we propose a novel authentication method which is easily adopted without modification and addition of the existed mobile hardware platform. Also, we present a simple implementation as a demonstration version. Based on virtual machine (VM) approach, the proposed model is to use a pseudo-random number which is confirmed by the VM in a user's mobile phone and then is sent to the authentication site. This is more secure and safe rather than use of a random number received by the previous SMS. For this payment operation, a user should register the serial number at the first step after downloading the VM software, by which can prevent the illegal payment use by a mobile copy-phone. Compared with the previous SMS approach, the proposed method can reduce the amount of packet size to 30% as well as the time. Therefore, the VM-based method is superior to the previous approaches in the viewpoint of security, packet size and transaction time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.199-208
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• 2017

Both cardiovascular diseases caused by decreased body composition and arterial compliance and falling induced by loss of muscle mass are frequent occurrences in the elderly. Therefore, elderly people are advised to perform elastic band resistance exercises to improve their body composition and arterial compliance. Thus, the purpose of this study was to examine the effects of 12 weeks of elastic band resistance training on the body composition, arterial compliance and falling index in elderly females (> 65 years). The elastic band resistance exercise program was administered 3 times per week for 60 minutes each time for 12 weeks. In addition, the exercise intensity was set to 11-14 on the Borg scale (6-20). Before and after the training period, the body composition (body weight (BW), muscle mass, % body fat, body mass index (BMI)), arterial compliance (ankle brachial index (ABI) and pulse wave velocity (PWV)) and risk of falling index were determined. (After the program?), the BW (p=.003), BMI (p=.002), PWV (p=.017) and risk of falling (p=.037) in the exercise group were significantly reduced, whereas the BW (p=.009) and BMI (p=.009) in the control group were significantly increased. In conclusion, the body weight, BMI and arterial compliance of elderly females were positively changed by the elastic band resistance training. Thus, the elastic band resistance exercise may be useful for elderly people to prevent metabolic syndrome and cardiovascular diseases and to reduce their risk of falling.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.128-139
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• 2017

Railway is one of the public transportation systems along with shipping and aviation. With the recent introduction of high speed train, its proportion is increasing rapidly, which results in the higher risk of catastrophic failures. The wheel bearing to support the train is one of the important components requiring higher reliability and safety in this aspect. Recently, many studies have been made under the name of prognostics and health management (PHM), for the purpose of fault diagnosis and failure prognosis of the bearing under operation. Among them, the most important step is to extract a feature that represents the fault status properly and is useful for accurate remaining life prediction. However, the conventional features have shown some limitations that make them less useful since they fluctuate over time even after the signal de-noising or do not show a distinct pattern of degradation which lack the monotonic trend over the cycles. In this study, a new method for feature extraction is proposed based on the observation of relative frequency energy shifting over the cycles, which is then converted into the feature using the information entropy. In order to demonstrate the method, traditional and new features are generated and compared using the bearing data named FEMTO which was provided by the FEMTO-ST institute for IEEE 2012 PHM Data Challenge competition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.897-903
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• 2010

Used gas to the vehicle fuel are the problems of the 'survival' beyond the 'quality of life' improvements and revive a new paradigm of 'sustainable development' which pursues economic development in harmony with environmental conservation. However, the fatalities caused by explosions and fires increases every year with the increase in the use of LPG; gas accidents in large-scale storage facilities also cause severe damage to property. In this study, a suitable storage tank is designed in which the surface area of the fuel exposed to flames is minimized in order to prevent explosions; thus, the occurrences of explosions in underground storage tanks can be minimized. According to the optimum design of storage tank obtained in this study, underground containment space was minimized; the minimized diameter and length of a 20-ton storage tank was 3 m and 4.83 m, respectively. Thus, safety was ensured since surface area exposed to flames decreased by 89.4%, which is less than the exposed surface area in the currently used storage tanks.

• Journal of Digital Convergence
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• v.15 no.8
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• pp.391-400
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• 2017

The purpose of this paper is to present the effect of image stimulation on body stability as a conceptual model and to investigate the effect of image stimulus(2D, VR) on body stability(hand stability) through experiments Recently, stereoscopic images such as virtual and augmented reality are combined with smart phones and exercise equipments, and the diffusion is becoming active. The possibility of a safety accident or human error is also increasing as it temporarily affects the balance of the body and hand stability after the image stimulus is removed. The conceptual model is presented based on the results of previous studies. Based on the experimental results, the conceptual model has been explained in combination with the human information processing process and cognitive resource models that take place in the brain. Twenty subjects were exposed to 2D and VR stimuli, and display fatigue was measured by cybersickness questionnaire and hand stability by hand steadiness tester. Experimental results show that VR images induce higher display fatigue and lower hand stability than 2D. In this study, it is meaningful that hand stability according to image type and display fatigue level which have not been tried yet is revealed through conceptual model and experiment.

• Fire Science and Engineering
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• v.31 no.6
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• pp.40-46
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• 2017

As one of the solutions to deal with economic loss caused by traffic congestion in metropolitan area, a deep underground road has been planned and implemented at home and abroad. The part of them has been pushed ahead with a double-deck scheme which has an advantage in constructability and cost efficiency comparing to traditional road tunnel. However, the double-deck tunnel has a lower floor height than the general road tunnel due to the special structure used as the upper and lower lines by installing the middle slab on one excavation section. Therefore, it is relatively weak against fire accidents and ventilation problems occurring in tunnels. Thus study to develop the life safety system optimized to a double-deck tunnel has been systematically carried out in order to overcome their weak point. In this study, automatic monitoring fire extinguisher (AMFE) is developed to suppress a fire and prevent its spread at early stage of tunnel fire, conducting the performance test through vehicle fire tests as verification. The tests were conducted with AMFE being 30 m apart from the vehicle and 10 m apart from engine room. As a results, it was confirmed that AMFE enables to suppress a fire and prevent its spread in both cases.

• Fire Science and Engineering
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• v.32 no.4
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• pp.110-121
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• 2018

The present article is concerned with a study on the daily training protocol for field crews wearing chemical protection clothing for firefighting and the analysis of activity. To improve coping ability of & secure safety for firefighting crews initially incorporated in the fields of chemical accident & chemical terror, 10 steps in total of daily training protocol have been designed. The designed protocol is largely composed of the extensive activity protocol for daily adaptation of firefighting chemical protection clothing (steps 1, 2, 6, 7 & 9), the precision operation protocol utilizing hands (steps 3, 4 & 5), and the protocol requiring strong physical burdens (steps 8 & 10). According to the measurement results for activity as a result of the protocol, the average maximum heart rate upon wearing the firefighting chemical protection clothing was shown to increase by step 1 20.32%, step 2 18.69%, step 3 25.23%, step 4 34.77%, step 5 27.44%, step 6 30.24%, step 7 25.33%, step 8 22.25%, step 9 22.80% and step 10 20.85% compared with the time of not wearing them. The average maximum breathing rate was shown to increase by step 3 1.92%, step 4 4.11%, step 5 1.24%, step 6 3.95%, step 7 0.93%, step 8 10.23%, step 9 3.36% and step 10 15.10%, except for steps 1 & 2.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.345-352
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• 2020

To preserve and restore tidal flats and prevent safety accidents, it is necessary to construct tidal flat topographic information including the exact location and shape of tidal creeks. In the tidal flats where the field surveying is difficult to apply, airborne LiDAR surveying can provide accurate terrain data for a wide area. On the other hand, we can economically obtain relatively high-resolution data from UAV (Unmanned Aerial Vehicle) surveying. In this study, we proposed the methodology to generate high-resolution topographic information of tidal flats effectively by integrating airborne LiDAR and UAV point clouds. For the purpose, automatic ICP (Iterative Closest Points) registration between two different datasets was conducted and tidal creeks were extracted by applying CSF (Cloth Simulation Filtering) algorithm. Then, we integrated high-density UAV data for tidal creeks and airborne LiDAR data for flat grounds. DEM (Digital Elevation Model) and tidal flat area and depth were generated from the integrated data to construct high-resolution topographic information for large-scale tidal flat map creation. As a result, UAV data was registered without GCP (Ground Control Point), and integrated data including detailed topographic information of tidal creeks with a relatively small data size was generated.