• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.100-109
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• 2008

Traffic accidents at night occur more than any other time because of improper road light facility and delineators. Therefore, cost-effective criteria of installing delineators are needed instead of expensive road light facility, especially, on rural road including light volume of traffic. This paper presents the criteria of installing 'Chevron Alignment Sign' considering driver's visual behavior characteristics and 'Raised Pavement Marker' considering critical encroachment angie of both straight section and curve one in order to reduce both the number of accidents on curve sections and the number of road encroachment accidents, respectively. The characteristics of visual behaviors can be expressed by visual angle involving curve radius and intersection angle. The estimated installing angles are $1^{\circ}{\sim}2.5^{\circ}$ by radii, which is based on changes in sensitivity across visual field by exogenous attention. Also, the raised pavement marker is installed every 2m, 3m, and 4m considering critical encroachment angles by radii.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.42-54
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• 2018

This study is to establish the traffic volume-based warrants of left-turn lanes in unsignalized intersections based on a risk probability methodology. This study applied a risk probability of a potential rear-end collision between a left-turn vehicle and the immediately following through vehicle. With the shifted negative exponential model and the compound probability theorem, the risk probability can be expressed as the function of directional volumes, opposing volumes and the percentage of left-turns for a two-lane and four-land highway, respectively. The warrants of installing left-turn lanes on unsignalized intersections were developed with the risk probability. The warrants define the total approaching and opposing volumes to encourage a left-turn lane as a function of operating speed, percentage of left-turn, and number of lanes.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.405-410
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• 2014

The purpose of this study in vitro investigation was to compare the marginal and internal fit of Ni-Cr alloy metal ceramic crown before and after porcelain veneering. Furthermore, this study evaluated whether the influence of the porcelain firing on the precision of fit of dental prostheses. The maxillary right incisor was selected as an abutment for experiments. Ten working models were prepared. Ni-Cr alloy cores appropriate for each abutment were prepared by lost wax technique. The marginal area and four internal areas of the crowns were measured at two stages: before veneering process and after upper porcelain firing. Silicone replica techniques were used. The data were statistically analyzed with the paired t-test (${\alpha}=0.05$). $Mean{\pm}SD$ marginal and internal gap were $67.1{\pm}23.3{\mu}m$ for the nickle chrome alloy core group and $74.4{\pm}21.9{\mu}m$ for the metal ceramic crown group. There were statistically significant differences in all investigated areas (p<0.05). Within the limitations of this study, none of the Ni-Cr alloy metal crown values measured after porcelain firing process exceeded $120{\mu}m$, which is the clinically acceptable threshold.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.235-236
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• 2014

군의 교육훈련간 디브리핑과 피드백 장치 활용을 통한 심폐소생술 교육방법을 적용하여 보다 효과적인 교육 방법을 확인하고 심폐소생술 수행 전 후 피로도를 검사하여 심폐소생술 술기가 숙달된 인원과 숙달되지 않은 인원의 피로도 차이를 분석함으로써 심폐소생술 교육프로그램의 기초자료를 제공하고자 한다. 현재 야전에서 응급처치교육을 받은 적이 없는 비 의무병인자로 전투병 생존법 교육 소집 대상자 중 참여 희망자 50명을 대상으로 하였다. 연구방법은 3가지 교육방법(디브리핑, 피드백장치, 디브리핑과 피드백장치 조합) 을 적용한 3개의 그룹에서 1,2,3차의 평가와 전체 디브리핑을 통해 심폐소생술 수행능력의 질적 향상에 미치는 영향과 동일 대상 중 희망자 20명에 한하여 심폐소생술 수행(5분) 전 후 혈중 젖산 농도 측정 및 주관적인 문답(1~10점)을 통해 심폐소생술 수행에 따른 피로도 실험을 진행하였다. 3가지 교육방법에 따른 심폐소생술수행능력 향상은 모든 그룹에서 유의하였으며(p<.001), 그룹별 심폐소생술 수행능력 향상효과의 차이는 디브리핑과 피드백장치를 조합하여 적용한 그룹에서 유의하게 높았다(p<.01). 심폐소생술 수행능력이 숙달되기 전 후의 피로도에 대해서는 본인이 느끼는 피로도는 유의한 차이는 없었으나 혈중 젖산농도에 따른 피로도는 유의한 차이로 전보다 후가 낮아졌다(p<.01).

• Journal of the Korean Society of Physical Medicine
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• v.5 no.4
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• pp.535-542
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• 2010

연구의 목적 : 건강한 20대 성인 남녀에게 복부 강화 운동의 하나인 warm-up (head to toe)와 tongue-stretching 운동 시 복근의 근 활성도를 비교하는데 연구의 목적이 있다. 연구의 방법 : 본 연구는 12명의 건강한 20대 성인 남녀(남 5, 여 7)를 대상으로 하였으며, 평균 연령은 26세이다. 연구의 대상자는 복근에 sEMG 도자를 부착하여 두 운동 적용 시 복부 근활성도에 대한 남녀의 차이와 개별 운동 시 각 근육간의 근활성도 차이를 SPSS 13.0을 이용하여 분석하였으며, 두 운동 적용 시 global 근육과 local 근육간의 비율을 1이라 가정하고 기여도를 측정하였다. 연구의 결과 : 연구의 결과는 다음과 같다. 1) 두 운동을 적용 시 남녀의 차이는 없었다. 2) 두 운동 적용 시각 근육간 근활성도 차이는 보이지 않았으나, 배속빗근(internal oblique)는 차이를 보였다. 3) 두 운동 적용 시global 근육과 local 근육간의 비율은 배곧은근(rectus abdominis)과 배속빗근과의 비율은 3으로 배속빗근이 배 곧은근의 근활성도 보다 컸음을 보였으며, 배바깥빗근(exernal oblique)과 배속빗근과의 비율은 약 1.5로 배속빗근의 활성도가 컸다. 연구의 결론 : 복부 강화 운동의 하나인 warm-up과 tongue-stretching 운동을 적용 시 복근의 활성도를 비교한 결과에서 보여주듯이 local 근육 강화 운동 시 두 운동의 효과를 향후 분석하여 요통환자와 같이 복부 강화가 필요한 환자의 프로그램에 적용되어져 할 것이다.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.83-91
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• 2012

This study deals with the operational efficiency of roundabout. The roundabouts generally have such the merits as high capacity, delay reduction, safety improvement, and others. Circular intersection can be divided into the rotary and roundabout according to travelling priority. The objective of this study is to comparatively analyze the operational efficiency of rotary and roundabout by scenario. In pursuing the above, this study gives the particular attentions to developing 256 scenarios according to the directional and entering traffic volume and analyzing the delay using VISSIM. The main results are as follows. First, the average delay of rotary was analyzed to be 1.56-8.74 times of roundabout. Second, the operational efficiencies of rotary and roundabout were analyzed to be better in the case of bigger differences in the traffic volumes between the main and minor roads. Third, the average delay of the 4-legged was evaluated to be 1.77-11.70 times of 3-legged intersection. Finally, 2-lane intersection (3-legged & 4-legged) was analyzed to be 2.02-2.23 times of 1-lane intersection.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.490-499
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• 2015

In this study, for the introduction factors of ERP system suggested in the prior study, I analyzed the importance of each introduction factor by using Delphi methodology and AHP. As a result of analysing the importance of the introduction factors of the 1st layer, the supplier factor was analyzed to be the most important factor among innovation factor, information technology factor, the user factor, the supplier factor, and in the weight analysis on the 2nd layer considering the importance of 1st layer, the standard work model of the supplier factor was a suitable factor, and the CEO participation factor(.086) was analyzed as the second most important introduction factor. These analysis results enable to determine that domestic Small & Medium enterprises' position hope to introduce by selecting a system in which the company characteristics and management strategies are applied well, because they should operate an ERP system that has already been developed, and in this course, the participation of CEO was also found to be a very important factor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.381-383
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• 2022

This study evaluated the completeness of emergency medical service (EMS) activity reports. In all, 67,830 cases of normal transfers were statistically analyzed using IBM SPSS Statistics version 22, and statistical significance was set at p <0.5. The 119EMT_2 certificate was omitted in 50,037 (73.8%) cases, followed by time-related items in 1,227 (1.8%) cases. In the primary assessment of vital signs, systolic blood pressure was omitted and erroneous in 1,218 (1.9%) and 1,129 (1.8%) cases, respectively. In the secondary assessment, the completeness of all vital sign items was approximately 70%. As the severity of the patient's condition increased, the errors in the EMS activity report also increased, at a significant level (p=.00). Paramedics must be aware of the importance of completing the activity report.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.186-195
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• 2017

Recently, autonomous vehicles have been studied actively. There are various technologies such as ITS, Connected Car, V2X and ADAS in order to realize such autonomous driving. Among these technologies, it is particularly important to recognize where the vehicle is on the road in order to change the lane and drive to the destination. Generally, it is done through GPS and camera image processing. However, there are limitations on the reliability of the positioning due to shaded areas such as tunnels in the case of GPS, and there are limitations in recognition and positioning according to the state of the road lane and the surrounding environment when performing the camera image processing. In this paper, we propose that LED lights should be installed for autonomous vehicles in tunnels which are shaded area of the GPS. In this paper, we show that it is possible to measure the position of the current lane of the autonomous vehicle by analyzing the color temperature after constructing the tunnel LED lighting simulation environment which illuminates light of different color temperature by lane. Based on the above, this paper proposes a lane positioning technique using tunnel LED lights.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.175-184
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• 2009

The study analyzes likely impacts of left truck lane restriction strategies on urban freeways based on a traffic simulation model. This study contains two main parts. The first part is performed to develop feasible alternatives as well as provide insights into conditions under left truck lane restrictions would be effective based on the analysis of two representative hypothetical highways. Different levels of O-D demands and truck percentage is at least restrictions would work when maximum rate of flow is more than 1,300vphpl or truck percentage is at least over loft of the total traffic. The second part of our study concerns a case study on a region with perhaps the highest truck volumes in the U.S. - a northbound section of Interstate 710 corridor in Los Angeles County, Southern California. The results show that restricting the two leftmost lanes under congested traffic with heavy ruck use, provides the most positive impacts in terms of improving the flow of traffic and saving fuel. In addition, our study demonstrates that in general, the number of lanes restricted is a crucial factor in the success of this strategy.