• Journal of Korean Society of Transportation
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• v.20 no.4
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• pp.123-134
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• 2002

감응식 신호운영변수 설계에 관한 연구는 정주기식 신호운영변수 설계의 그것보다 그 수준이 현저히 미비하며 이는 감응식 신호운영 특성을 반영한 평가방법의 부재로 감응식 운영변수의 평가가 불가능하였기 때문이다. 본 논문은 최근에 소개된 평균 감응현시 녹색시간 추정 수리모형을 이용하여 Highway Capacity Manual (HCM) 지체도를 최소화하는 최대녹색시간의 설계방안을 제시한다. - '최소녹색시간'과 '단위연장시간'은 보행자 횡단시간 및 차량 차두시간 등 지역별 운전자/보행자의 특성과 관련이 있어 일반적인 최적화 설계 수리모형의 적용에 무리가 있어 제외한다. 제안된 설계방안은 감응식 운영논리를 토대로 감응현시 군의 평균녹색시간과 평균주기를 산정하며, HCM 지체도를 평가하고, 가능한 대안 중 지체를 최소화하는 최대녹색시간 운영변수 군을 '혼혈 유전자 알고리즘'으로 도출한다. 현장실험을 통해 도출이 불가능한 실제 최적치를 Corridor Simulation(CORSIM)모형을 이용하여 추정하였고 이를 제안된 설계방안으로 도출된 최대녹색시간 운영변수' 값들과 비교하였다. 비교결과 교차로 v/c 비율이 1.0 보다 낮을 시는 제안된 방법을 통해 설계된 최대녹색시간 운영변수 군이 최소 CORSIM 지체도를 산출하는 최대녹색시간 운영변수 군과 동일한 것으로, v/c비율이 1.0보다 높을 시는 다른 것으로 결과되었다. v/c비율이 1.0 보다 높은 경우는 정주기식 교차로 운영에 효율적이라 감응식 운영의 필요를 벗어나므로 제안된 최대녹색시간 설계방안은 감응식 신호운영 필요범위 내에서 효율적이다. 기존의 최대녹색시간 설계는 정수기식 최적녹색시간을 기준으로 최대녹색시간을 추정하며, 그러한 과정을 돕기 위하여 추정범위(설계자가 범위 내에서 임의로 선택함)를 제시하는 것이 기존의 연구임을 비교하면 본 연구에서 제안하고 있는 설계방법의 의미가 크다.

• Science of Emotion and Sensibility
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• v.16 no.2
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• pp.235-248
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• 2013

In this study, the effects of driver's neuroticism on situation awareness(SA), eye movement(EM), and driving performance were examined. In Experiment 1, in which static driving scenes were presented, it was found that the drivers of higher neuroticism showed shorter percentage of dwell time and less percentage of fixation counts for the peripheral area than those of lower neuroticism, although SA scores yielded no difference between the two neuroticism groups. In Experiment 2, differences in the drivers' driving performances as well as SA and EM as a function of neuroticism were compared using driving simulation. The results of Experiment 2 showed the followings. First, contrasting to Experiment 1, the high neuroticism group showed lower SA score than low neuroticism group. Second, the pattern of EM was similar to those of Experiment 1. Third, high neuroticism group deviated more from center of road, and drove slower than low neuroticism group.

• 한국해양학회지
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• v.24 no.4
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• pp.194-205
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• 1989

In order to study the biomass of primary producer, phytoplankton is collected monthly September 1985 to August 1986 in Ch$\check{o}$nsu Bay. Phytoplankton carbon contents which are calculated from phytoplankton volume were ranged from $26.7{\mu}gC/l$ to $960.7{\mu}gC/l$, and average carbon contents of each month lie in the range of $58.6-684.7{\mu}gC/l$(annual mean $208.5{\mu}gC/l$). For net plankton analysis with the carbon contents, cell numbers, and chlorophyll concentrations show a close correlation, while for nanoplankton the correlation was low, indicating that nano-fraction includes a significant portion of picoplankton. Also, the multiple regression analysis with carbon content, cell number, and chlorophyll concentration to size fraction well illustrate the prime importance of the net-fraction in phytoplankton group. C/Chl-a ratios ranged from 9.1 to 100.5, average rations of net- and nanoplankton are 111 and 6.4, respectively. The greater net plankton faction is, the higher C/Chl-a ratio is, however in case of high nanoplankton portion C/Chl-a ratio show low level. These results indicate that the difference of C/Chl-a ratio per phytoplankton cell size be main factor for the variation of C/Chl-a ratio in Ch$\check{o}$nsu Bay. As C/Chl-a ratio fluctuates greatly in coastal ecosystem, that use of a direct conversion of convert chlorophyll to organic carbon may lead erronous estimation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.165-170
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• 1992

The internal shell morphology of the blue mussel, which were collected from Korea and Japan were studied. The range of the mean ratio between anterior adductor muscle scars to shell height in each locality were between 62.47 in Yongdok to 54.17 in Uichang. These values were very similar to that of M galloprouincialis in Mediterranean than that of M edulis in Europe. And the range of the mean ratio between hinge plate length to shell height were between 61.31 in Jukbyon to 56.15 in Otuschi. Also these values were similar to that of M. galloprovincialis in Mediterranean. Based on the mean ratio between anterior adductor muscle scars and hinge plate length to shell height, it was suggested that the Korean and Japanese blue mussel is certainly identical to the Mediterranean species, Mytilus galloprovincialis.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.5
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• pp.584-594
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• 1999

이 논문에서는 CDMA(Code Division Multiple Access)셀룰러 시스템에서 우선순위 큐(Queue)에 기반을 둔 핸드오프채널할당기법의 모델을 제안하였다. 또한 제안한 모델의 성능을 컴퓨터 시뮬레이션을 통해 비우선순위기법 및 FIFO(First In First Out)큐기법과 비교하였다. 제안하는 모델의 핸드오프 채널할당 기법에서는 이동국의 진행방향에 있는 인접 셀(Neighbor Cell)의 파일롯 중에서 임계치가 T-ADD 이상인 파일롯이 있을 경우 기지국이 이 파일롯(Pilot)에 대한 파일롯 세기 측정메시지를 이동국으로부터 수신 한 지점에서 드롭타이머가 종료된후 현재의 셀에서 사용중인 파일롯에 대한 파일롯 세기 측정 메시지를 이동국으로부터 수신한 시점까지 핸드오프 처리가능 영역으로 정의하고 이를 우선순위 큐의 최대큐 대기시간으로 사용하였다. 제안된 기법의 성능을 분석하기 위한 성능평가 척도는 강조종료확률, 호 블록킹 확률, 전체 제공 트래픽에 대한 수행 트래픽 비율, 평균 규크기미치 핸드오프 시 평균 지연시간이다. 성능시뮬레이션결과, 제안된 기법이 전체 시스템 호처리 용량면에서 약간의 단점은 발생하지만 핸드오프 처리에 있어서 높은 성능을 유지함을 알수 있었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4
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• pp.145-155
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• 1992

The objective of the study is to evaluate the effect of variabilities (uncertainties) in materials and testing on contractor payment and to suggest a base for adjusting the unsuitable specification. Most commonly used acceptance plans were used to estimate payment using simulation. Simulation results that were graphically illustrated by means of operating characteristics (OC) curves in terms of expected payment showed that contractor received a reduced payment due to intrinsic sampling and test variabilies. The most significant reduction was caused due to relatively large magnitude of the testing variability. Therefore, the tolerance range in acceptance plan should be revised as compared with typical testing variability.

• Journal of Internet Computing and Services
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• v.17 no.1
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• pp.47-53
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• 2016

A type of workflow affiliation network is one of the specialized social network types, which represents the associative relation between actors and activities. There are many methods on a workflow affiliation network measuring centralities such as degree centrality, closeness centrality, betweenness centrality, eigenvector centrality. In particular, we are interested in the closeness centrality measurements on a workflow affiliation network discovered from enterprise workflow models, and we know that the time complexity problem is raised according to increasing the size of the workflow affiliation network. This paper proposes an estimated ranking algorithm and analyzes the accuracy and average computation time of the proposed algorithm. As a result, we show that the accuracy improves 47.5%, 29.44% in the sizes of network and the rates of samples, respectively. Also the estimated ranking algorithm's average computation time improves more than 82.40%, comparison with the original algorithm, when the network size is 2400, sampling rate is 30%.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.299-306
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• 2023

In this study, the O/W emulsification processes with the natural surfactants that were extracted from Medicago sativa L. and Sapindus saponaria L. as emulsifiers were optimized using the central composite design-response surface methodology (CCD-RSM). Herein, independent parameters were the amounts of mixed emulsifiers, the mixing ratio of natural emulsifiers (soapberry saponin/alfalfa saponin), and the emulsification time, whereas the reaction parameters were the emulsion stability index (ESI), mean droplet size (MDS), and antioxidant activity (DPPH radical scanvenging activity). Through basic experiments, the ranges of operation variables for the amount of mixed emulsifiers, the mixing ratio of natural emulsifiers, and the emulsification time were 12~14 wt%, 30~70%, and 20~30 min, respectively. The optimum operation variables deduced from CCD-RSM for the amount of mixed emulsifiers, the mixing ratio of natural emulsifiers, and the emulsification time were 13.2 wt%, 44.2%, and 25.8 min, respectively. Under these optimal conditions, the expected values of the ESI, MDS, and antioxidant activity were 88.7%, 815.5 nm, and 38.7%, respectively. And, the measured values of the ESI, MDS, and antioxidant activity were 90.6%, 830.2 nm, and 39.6%, respectively, and the average experimental error for validating the accuracy was about 2.1%. Therefore, it was possible to design an optimization process for evaluating the O/W emulsion process using CCD-RSM.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.274-282
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• 2013

The goal of this study was to analyze prevalence and distribution of congenitally missing teeth in 3302 patients from 7 to 15 years old, who had visited and taken panoramic radiographs at the Department of Pediatric Dentistry, from January 2008 to December 2012. The prevalence of hypodontia in the males (5.9%) was slightly higher than in the females (4.7%). In the affected patients, the mean number of congenitally missing teeth in the mandible was statistically higher than in the maxilla (p < 0.05). However, there was no significant difference in the number of congenitally missing teeth between left and right dentitions (p > 0.05). Excluding the Mn. third molars, the most frequent congenitally missing teeth site was the Mn. second premolars. In contrast, the most infrequent congenitally missing teeth sites were the Mx. and Mn. first premolars, and Mx. central incisors. The bilateral combination or antagonistic quadrants combination of congenitally missing teeth in hypodontia patients was 80.3%. The result of this study will contribute to clinicians to make accurate diagnosis and establish favorable treatment plans, by offering invaluable data about the number and distribution of congenitally missing teeth.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.10-21
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• 2013

This study suggested combined filtering model to eliminate outlier travel time data in transportation information system, and it was based on Median Absolute Deviation and Voting Rule. This model applied Median Absolute Deviation (MAD) method to follow normal distribution as first filtering process. After that, Voting rule is applied to eliminate remaining outlier travel time data after Median Absolute Deviation. In Voting Rule, travel time samples are judged as outliers according to travel-time difference between sample data and mean data. Elimination or not of outliers are determined using a majority rule. In case study of national highway No. 3, combined filtering model selectively eliminated outliers only and could improve accuracy of estimated travel time.