• Korean Journal of Construction Engineering and Management
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• v.15 no.5
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• pp.40-48
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• 2014

As CBR(Chemical, Biological, and Radiological) attack increases, the importance of CBR protective facilities is being emphasized. When CBR warfare emerges, a task force team, who exist outside of CBR protective facility, should enter the CBR protective facility through neutralizing process in CCA(Contamination Control Area) and TFA(Toxic Free Area). If a bottleneck occurs in the process or zones, the task force team cannot enter the CBR protective facility efficiently and may cause inefficiency in its operation performance or result in casualties. The current design criteria of the CBR protective facility is only limited to ventilation system and it does not consider how much time it takes to enter the facility. Therefore, this research aims to propose the entering time estimation model with discrete event simulation. To make the simulation model, the procedure performed through CCA and TFA is defined and segmented. The actual time of the procedure are measured and adapted for the simulation model. After running the simulation model, variables effecting the entering time are selected for alternatives with adjustments. This entering time estimation model for CBR protective facility is expected to help take time into consideration during the designing phase of CBR protective facility and help CBR protective facility managers to plan facility operation in a more realistic approach.

• The Journal of the Petrological Society of Korea
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• v.11 no.3_4
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• pp.200-213
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• 2002

The Andong granitoid batholith represents five temporally distinct episodes (phases) of igneous activity. The batholith represents a plutonic complex of five pulsatively emplaced distinct intrusive multiphases. The petrochemical data show that the plutons fall into calc-alkaline series except for the Yean pluton, and plot within the diaenostic range for I-type origin and continental arc orogenic tectonic setting. Each pluton reveals systematic compositional variations of major and trace elements with $SiO_2$ or MgO, but different variation trends for some elements and considerably different REE patterns. Thus discontinuous, inconsistent variations in the elements indicate that the five plutons can not be explained by simple fractional crystallization from the same primary magma, but were intruded and solidified from the independent magmas of chemically heterogeneous origin. In the Andong, Dosan and Pungsan plutons, high values of molar CaO/(MgO+$FeO^{t}$ ) combined with low $Al_2$$O_3$/(MgO+$FeO^{t}$ ) and $K_2$O$Na_2$O ratios suggest a magma originated by dehydration melting of a metabasaltic to metatonalitic protolith. Whereas the Imha pluton show similar values of CaO/(MgO+$FeO^{t}$ ), but significantly higher ratios of $Al_2$$O_3$/(MgO+$FeO^{t}$ ) and $K_2$O$Na_2$O implying to a metagreywacke protolith.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.2
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• pp.10-18
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• 2017

The University library is a reality where facilities can be a massive upset by the space of students to study space and book materials. Also, many print materials can cause fires quickly in fires, resulting in massive amounts of human casualties caused by many toxic gases. This study purpose is compares the time spent in the evacuation of the current state through the simulation, which seeks to derive a reasonable library of evacuation design, and improved inside the evacuation. As a result, the most obvious way to reduce the time required to evacuate is to diversify the evacuation routes and to disperse them. However, if the extension of the gate is not feasible, it is possible to reduce the time of escape by increasing the width of the gate and the width of the stair. If the results of this study are applied to new construction or remodeling of the library and prepare for fire evacuation, it will be a much safer library facility.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.595-603
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• 2017

We propose a scheme to reduce the time for the SSL/TLS handshake by embedding it into the TCP 3-way handshake. The scheme can be selectively applied on the standard TCP for making the SSL/TCP handshake happen within the TCP handshake, rather than performing the TCP handshake and SSL/TLS handshake in sequence. We implemented a prototype of the scheme and did some experiments on its performance. Experimental results showed that, compared to the sequential handshakes of the TCP and the SSL/TLS, the time reduction achieved by the scheme varied in the range of 3.2% and 14%(when the elapsed time by the ping program from the client to the server was 11.6ms). The longer the time measured by the ping program, which would grow as the propagation and queuing delays do, the larger the reduction rate. It accords with the supposition that the reduced time due to the scheme will increase in proportion to the amount of the elapsed time measured by the ping program.

• The Journal of the Petrological Society of Korea
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• v.9 no.4
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• pp.238-253
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• 2000

In the eastern part of the Euiseong Basin acidic~intermediate volcanic rocks widely distribute on the Cretaceous sedimentary basement. Coeval granitic rocks and dyke rocks intruded into the volcanic rocks. Volcanic stratigraphy of study area are andesite lava, dacitic lapilli tuff, dacitic flow-banded lava, rhyolitic bedded tuff, rhyolitic massive tuff, dacitic massive lava, rhyolitlc welded tuff occur from the lower to the upper strata. $SiO_2$ content of the volcanic rocks range from 51 to 74 wt.%. With the increase of $SiO_2$, the contents of $TiO_2$, $Al_2$$O_3$, MgO, FeOT MnO, CaO, $P_2$$O_{5}$ decrease but those of $K_2$O increase. The contents of $Na_2$O show dispersive variation. This trend is quite sim-ilar to the major oxide variation in the volcanic rocks from the Yucheon sub-basin. The geochemical natures indicate that the volcanic rocks in the study area are discriminated to the island-arc type high K to medium K calc-alkaline rocks. The compositional variation of the volcanic rocks can be explained by the plagioclase fractionation of the volcanic magmas originated from similar source materials. The volcanic stratigraphy seems to have formed by at least two eruptive sequences of andesitic to rhyolitic and dacitic to rhyolitic magmas which underwent crystallization differentiation.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.17-29
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• 2000

본 연구는 지하횡단보도 이용시 계단에서 나타나는 보행자 특성에 관한 연구로써, 교차로에서 횡단보도와 지하보도에서 보행자의 편의성을 정량화한 것이다. 지하보도 계단에서의 보행자특성에 관한 연구, 즉 속도, 밀도와 보행자교통량에 관한 연구는 비디오촬영을 통하여 수집한 자료를 분석하였다. 지하보도나 횡단보도 횡단시 이동 거리, 소요시간, 소요에너지는 보행자특성 분석에서 나온 결과와 직접 시설을 조사한 자료를 이용하여 비교하였다. 주요 연구결과는 다음과 같다. 첫째, 지하보도 계단에서 보행자 속도는 상향이동시의 평균속도는 37.7m/분(또는 0.67m/초)이고, 하향이동시의 평균속도는 46.7m/분(또는 0.77m/초)으로 나타났다. 둘째, 평균 이동거리는 단순횡단의 경우 지하보도는 119m이고, 횡단보도는 78m이다. 대각횡단의 경우 지하 보도는 161m이고, 횡단보도는 111m이다. 평균 소요시간은 단순횡단의 경우 지하보도는 125.6초이고, 횡단보도는 111.3초로 나타났다. 대각횡단의 경우 지하보도는 162.3초이고, 횡단보도는 178.8초로 나타났다. 평균 소요에너지는 단순횡단의 경우 지하보도는 20.2kcal이고, 횡단보도는 4.7kcal이다. 대각횡단의 경우 지하보도는 23.5kcal이고, 횡단보도는 6.6kcal이다. 단순횡단시 지하보도가 횡단보도보다 이동거리는 평균 1.5배 더 길고, 시간은 평균 1.2배 더 소요되고, 에너지는 평균 4.5배가 더 소요된다. 대각횡단시 이동거리는 평균 1.5배 더 길고, 소요시간은 비슷하고, 에너지는 평균 3.5배 더 소요되었다. 본 연구는 기존의 교차로나 가로구간에 지하보도만 설치되어 있는 지점에 횡단보도의 설치여부에 관한 정책결정을 하는데 도움이 될 수 있을 것이다.

• Proceedings of the KSCN Conference
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• 2003.11a
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• pp.1084-1085
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• 2003

최근 대학생들은 초등학교 때부터 혹은 중학교 때부터 급식을 받아온 세대로 급식체계에 싫증을 내고 학교 밖의 외부식당으로 눈을 돌리고 있는 세대이다. 또한, 위탁급식전문업체의 대학 내 급식사업 참여와 많은 선행 연구 등을 토대로 여러 면에서 대학 내 구내식당이 개선되고 있으나 아직도 매우 부족한 실정이다. 따라서, 본 연구는 외부식당과의 경쟁으로 현재 급식인원수가 매년 감소하여 운영상의 어려움을 겪고 있는 S 대학 학생식당 고객의 급식소 선택속성에 대한 의견을 조사하고 현재 운영중인 급식소 이외에 추가 설립하고자 하는 식당 신설에 대한 전략을 도출하고자 한다. SPSS통계 package (ver. 11.0)를 활용하여 기술통계(descriptive analysis), 컨조인트 분석 (conjoint analysis)을 실시하였다. 현재 학생식당 이용빈도 감소원인은 ‘음식이 맛이 없어서’가 44.8%, ‘거리가 멀기 때문’이 19.9%로 조사되어, 학생식당의 이용빈도에 가장 큰 영향을 주는 것은 '음식 맛'과 '거리'인 것으로 파악되었으며, 학생식당에 대한 전반적인 만족도는 ‘보통이다’가 37.8%, ‘불만족 한다’가 36%, ‘매우 불만족한다’가 18.4%, ‘만족한다’가 7.8%로 조사되어 응답자의 대부분이 식당에 대해 불만족하고 있었다. 거리에 의해 식당의 이용빈도가 감소하고 있는 것은 현 학생식당의 위치가 강의 동과 먼 거리에 위치하고 있어 강의 동이 밀집해 있는 건물과 근거리에 식당이 개설된다면 이용할 의사가 있는지 여부에 대해 64.7%가 이용하겠다는 의사를 밝혔고 26.1%는 이용하지 않겠다고 응답했다. 따라서, 학생들이 인식하는 적정 거리의 식당 위치를 파악하기 위해 식당으로 이용하는 소요시간에 대해서 조사대상자가 멀다고 인식하는 시간과 가까운 거리라고 인식하는 시간에 대한 조사 결과 가까운 거리로 인지하는 평균 이동소요시간(분)은 5분이었으며 먼 거리로 인지하는 평균이동소요시간은 10.9분으로 적당한 식당의 위치는 S~10분내의 거리로 9분 30초의 거리에 식당이 위치하면 학생들의 이용률을 극대화시킬 수 있을 거라 사료된다. 사전 대면면접을 통해 가격, 소요시간, 음식의 맛으로 선정된 속성과 각 속성별 수준을 활용한 컨조인트 분석 실시하여 도출된 학생들의 급식소 선택 시 중요하게 인식하는 속성은 가격대, 소요 시간, 음식 맛 순으로 나타났으며, 각각의 중요도는 가격이 65.42%, 소요시간인 24.76%, 음식의 맛이 9.82%였다. 즉, 학생들은 학생식당의 서비스 품질 속성 중에서 상대적으로 식사 가격을 가장 중요하기 생각하는 것으로 나타났고, 다음으로는 식사를 하기 위해 식당까지 가는데 소요되는 시간, 음식의 맛을 중요하게 생각하는 것으로 분석되었다. 컨조인트 분석결과 조사대상자가 가장 선호하는 대학 식당으로는 이동하는데 6-10분이 소요되는 거리에 위치한 식당으로 2,100-2,500원 정도의 가격대로 맛있고 깔끔한 식당을 가장 선호하는 것으로 조사되었다. 따라서, 현재 운영중인 학생식당이 모두 1,800원의 단일 식단가로 운영되고 있는 점을 감안하여 학생식당을 신설할 경우에는 이동하는데 10분 이상 소요되지 않는 장소에 가격대는 현재보다 더 높은 2,000-2,500원의 가격대에서 맛있고 깔끔한 현재와는 차별화 된 일품메뉴 위주의 식단의 학생식당을 신설하는 것이 바람직할 것으로 사료된다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.5
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• pp.51-56
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• 2020

Measurement accuracy and required time is important to make ATE(Automatic test equipment) system in Ka band, and SCPI commands of power meter which is a representative RF test equipment are studied in this paper. Comparison data between FETCH and MEASURE which are SCPI commands are measured in 30 G ~ 31 GHz and -70 ~ +20 dBm using two power sensor. The data show that FETCH which is the fastest SCPI is able to get reliable data in linear interval above noise level. MEASURE which is the best accurate command takes longer time than FETCH, and the longest time is 13.2 seconds. These results offer that measurement accuracy and required time of the two SCPI for power meter and would be used as a guideline for efficient ATE system in Ka band.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.167-189
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• 2022

In the case of SAE autonomous driving levels 2 and 3, since complete autonomous driving is impossible, the take-over process is essential, and take-over time(TOT) is the most important factor in determining the safety of the autonomous driving system. Accordingly, research on TOT is being actively conducted, but each research is independently conducted and general conclusions that integrate various research results are required. Therefore, in this study, the factors affecting TOT were analyzed using meta-analysis, which integrates the results of individual studies and presents an integrated opinion. As a result of meta-analysis, a total of 10 influencing factors were selected, and most of them were related to the non-driving related task(NDRT) type. In addition, implications for the future research direction of take-over and NDRT were presented.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.4
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• pp.419-426
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• 2016

For this research 20 supernumerary teeth impacted in the maxillary anterior have been extracted and pulp cells have been collected from them. From the collected pulp cells, total of 17 (10 males, 7 females) have been selected as subjects. From this research, the run-time of successive culture of the cell from tooth number pulp tissue was $2.91{\pm}0.29$ days. From the gathering of cells from the initial pulp tissue until gaining 80% confluency took $4.53{\pm}0.94$ which was the longest. The following successive cultures took $2.73{\pm}0.32$ days. Average runtime for female was $2.81{\pm}0.27$ days whereas male had average runtime of $2.98{\pm}0.29$ days. Average run-time for inversion was $2.94{\pm}0.30$ days and for normal location, $2.80{\pm}0.20$ days. Average runtime was $2.92{\pm}0.31$ days and other forms took $2.88{\pm}0.22$ days. In the future, follow up research would be needed to evaluate the efficiency of the cells collected from the initial passage and the latter passage as stem-cells and taking into consideration the less than 3 days'time for the subculture, it could be concluded that the research efficiency and fast cultivation would be sufficiently effective.