• Environmental and Resource Economics Review
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• v.11 no.1
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• pp.57-79
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• 2002

동 연구는 미국 캘리포니아주 San Joaquin Valley의 고정오염원들로부터 발생되는 ROG(Reactive Organic Gases) 배출량을 저감하기 위하여 명령통제방식(CAC)과 경제적 유인제도를 적용할 경우의 비용효과성을 비교 분석하였다. 경제적 유인제도로서는 UMPS(uniform marketable permit system)와 LMPS(localized marketable permit system) 배출권거래제도를 적용하였다. 분석결과 배출권거래제도(UMPS, LMPS)를 이용한 ROG 배출량 저감이 명령통제방식보다 비용이 적게 드는 것으로 나타났다. 한편, one-to-one permits trading이 허용되는 UMPS의 경우에는 일부 특정 지역에 대한 환경질이 악화되는 결과를 초래하는 경우가 발생하여, 궁극적으로 San Joaquin Valley의 ROG 배출량 저감을 위해서는 UMPS 방식의 배출권거래제도 도입이 보다 바람직한 것으로 나타났다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.415-418
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• 2008

This paper presents a method for moving objects detection, analysis and expression how much move as numerical value from the image which is captured by a network camera. To perform this method, we process few kinds of pre-processing to remove noise that are getting background image, difference image, binarization and so on. And to consider perspective effect, we propose modified ART2 algorithm. Finally, we express the result of ATR2 clustering as numerical value. This method is robust to size of object which is changed by perspective effect.

• Journal of Korea Port Economic Association
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• v.29 no.3
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• pp.95-111
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• 2013

The purpose of this study is to draw out the trade effect of the Korea ASEAN FTA by carrying out a panel analysis. For achieving such a purpose, Panel Unit Root, Panel Cointegration Test, Pooled OLS, Hausman Test, Fixed Effect, Random effect are performed. The last 15 years's data over the period of 1997 to 2011 concentrated on the ASEAN countries such as Indonesia, Malaysia, Philippine, Singapore, Thai, Vietnam is used in this study. Major implications are summarized as following. First, our government need to maximize the effect derived from conclusion of FTA(Free Trade Agreement) in order to enhance the competitive edge through obtaining a stable foreign market. Second, it necessary for our government to improve a national system by orienting a FTA conclusion complying with WTO's product and service-related regulation.

• Journal of the Society of Disaster Information
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• v.8 no.1
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• pp.27-35
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• 2012

The main objective of this paper is to evaluate the field applications and the noise reductions of micro surfacing pavement, which is often used to reduce environmental problems. A traffic noise mechanism was analyzed and a modified mix design method was proposed for nighttime constructions. Results on noise measurements using the statistical pass-by method showed noise reductions of 2.0 to 7.1 dB were observed. In addition, results on noise measurements using the close proximity method demonstrated that noise reductions of 5.6 to 6.7 dB were recorded under vehicle speed of 80km/h. The noise measurements revealed that the close proximity method was more stable than the statistical pass-by method. As a result, the effect of micro surfacing pavement on noise reductions was proved through the research. It is considered that the micro surfacing pavement method could be used as a preventive maintenance method and a comfortable noise reducing pavement technique.

• Korean Journal of Labor Studies
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• v.24 no.2
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• pp.181-214
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• 2018

This study uses the youth panel survey (YP2007 2th ~ 9th) data of the Korea Employment Information Service to examine the phenomenon of subjective mismatch arising from the youth labor market and analyzed the determinants and wage effects of subjective mismatch. Overall, the analysis showed that the over-education and over-technology of both educational background and technical skill level in the Miss Match significantly decreased, while the lack of education and technology increased rather gradually. Next, the analysis of the determinants of downward employment(Excess of education and technology) showed that males were less likely to be downwardly employed(Excess of education and technology) than females, and in the status of workers, the probability of downward employment of regular and non-wage workers was lower than that of temporary/daily workers. Finally, as a result of estimating the wage effect of the mismatch based on the pooled OLS model and the Panel Fixed Effect model, the mismatch which has the greatest effect on the wage was found to be excessive education, and it has been estimated that youth employees who are over-educated have an average 6.7% lower wages than those who are not. After controlling for the unobserved individual characteristics, they were found to receive a lower wage of 3.2%, and it is estimated that 2.9% for the technical excess mismatch and 2.3% for the major mismatch receive lower wages than the reference group.

• Korean Journal of Social Welfare Studies
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• v.40 no.2
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• pp.313-335
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• 2009

The objective of this study was to examine the association between participation in volunteer activities and self-esteem among adolescents. This study used data from the wave3-5(2005-2007) of Korean Youth Panel Study(KYPS). This study analyzed data of 3,449 second grade middle school students cohort. Fixed effects model using Proc GLM procedure in SAS was adopted to examine association between participation in volunteer activities and self-esteem among study participants. The results show that life satisfaction, appearance stress, relationship with parents, relationship with siblings, grades, relationship with teachers, and relationship with friends were significantly associated with self-esteem. Volunteer activities participation was associated with increased level of self-esteem.

• Journal of Korea Multimedia Society
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• v.10 no.4
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• pp.548-558
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• 2007

This paper presents a method of location sensing of mobile objects using RF devices. By analyzing signal strengths between a certain number of fixed RF devices and a moving RF device, we can recognize the location of a moving object in real time. Firstly, signal strength values between RF devices are gathered, and then the values are normalized and constructed as a model feature vector for specific location. A number of model patterns are acquired and registered for all of the location which we want to recognize. For location sensing, signal strength information for an arbitrary moving RF device is acquired and compared with model feature vectors registered previously. In this case, distance value is calculated and the moving RF device is classified as one of the known model patterns. Experimental results show that our methods have performed the location sensing successfully with 100% rate of recognition when the number of fixed RF devices is 10 or more than 12. In terms of cost and applicability, experimental results seem to be very encouraging.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.89-99
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• 2001

The conventional studies on equilibrium network design problem(ENDP) with fixed travel demand models assume that the future OD travel demand might not be changed even if the structure and the capacity of the network are improved. But this fixed demand assumption may loose its validity in the long-range network design because OD travel demand actually shifts with the network service level. Thus, it is desirable to involve the variable travel demand which is determined endogenously in the model in the optimal network design. In this paper a hi-level model formulation and solution procedure for ENDP with variable travel demand are presented. Firstly It is considered how to measure the net user benefits to be derived from the improved in link capacities, and the equilibrium network design problem considered here is to maximize the increase of net user benefit which results from a set of lift capacity enhancements within the budget constraints, while the OD travel demands and link travel times are obtained by solving the lower level network equilibrium problem with variable demand. And secondly sensitivity analysis is carried out to find the links to which the network equilibrium flow pattern is the most sensitive. Finally numerical example with simple network is carried out to test the validity of the model.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1259-1263
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• 2008

인천청라 경제자유구역내의 중앙호수공원을 대상으로 100년빈도 홍수시 Off-Line저류지로써 횡월류부에 가동보 설치에 따른 공촌천 홍수조절효과를 분석하였다. 서해조위 및 배수갑문 운영 등의 다양한 변수를 고려해야 하는 본 하천의 특성상 흐름상태의 시 공간적 변화를 고려하고 Off-Line 저류지 해석에 있어 실제 지형을 충분히 반영할수 있는 HEC-RAS 부정류 해석을 수행하였다. 부정류 모의 시 가동보의 도복을 합리적으로 검토 하기 위해 도복발생 시간을 기준으로 2단계에 걸쳐 부정류 모의를 수행하였다. 즉, 1단계에서 호수공원 횡월류 Weir높이를 가동보 높이로 고정하고 부정류 모의를 수행하여 공촌천의 호수공원 횡월류부 지점의 수위가 가동보 높이와 같아지는 시간을 찾고, 2단계에서 그 시간을 기준으로 호수공원 횡월류 Weir높이를 가동보가 없을 때의 높이로 부정류 모의를 수행하여 공촌천의 내수위를 검토하였으며, 가동보가 설치되지 않았을 때의 결과와 비교하여 가동보 설치에 따른 홍수조절효과를 분석하였다. 본 연구방법에서 검토된 공촌천 내수위의 적정성을 검토하기 위하여 배수갑문 운영에 따른 수위 변화를 모의 할 수 있는 Gate 모형으로 공촌천 하류의 배수갑문 지점에 대한 내수위를 산정하였으며, 하천 상류구간의 배수영향을 HEC-RAS를 이용한 부등류 모의를 추가적으로 수행하여 본 연구방법의 결과와 비교 검토하였다. 공촌천의 내수위 비교를 통한 홍수조절효과 분석결과 $2{\sim}3cm$ 정도의 홍수조절 효과가 있는 것으로 분석되었으며, 본 연구에서 제안한 방법이 가동보 설치에 따른 홍수조절효과분석 시 적용이 가능하리라 판단된다.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.289-294
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• 2015

Linear mixed models are commonly used in the clinical pharmaceutical studies to analyze repeated measures such as the crossover study data of bioequivalence studies. In these models, random effects describe the correlation between repeated outcomes and variance-covariance matrix explain within-subject variabilities. Bioequivalence analysis verifies whether a 90% confidence interval for geometric mean ratio of Cmax and AUC between reference drug and test drug is included in the bioequivalence margin [0.8, 1.25] performed using linear mixed models with period, sequence and treatment effects as fixed and sequence nested subject effects as random. A Levofloxacin study is referred to for an example of real data analysis.