• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.116-122
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• 2015

A simulation is applied to evaluate sea surface observations such as wave heights and surface currents by using a microwave Doppler radar. It is reported that the microwave irradiation width on the sea surface and Fourier transform time taken to sample data for frequency analysis affect Doppler spectra. To investigate the influences by these parameters, Doppler spectra are simulated with various numerical sea surface waves with currents. From the results, in the case of the microwave irradiation width is five times smaller than the wavelength of the sea surface wave, and the Fourier transform time is also five times shorter than the period of the sea surface wave, there is a possibility to measure wave heights accurately with a Doppler radar. In addition, relative surface currents can be estimated by analysis of long Fourier transform time. The simulation results showed the appropriate observing conditions with a microwave Doppler radar.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.71-82
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• 1998

This study focuses on one of the most typical energy-intensive industries, the steel industry. The two-fold purpose of the study is to develop a model to assess measures to alleviate sulfur dioxide($SO_2$) emissions from the steel industry and to propose a concrete $SO_2$ emission reduction measure from the steel industry. This study partially employed and modified AIM(Asia-Pacific Integrated Model) developed by Japan National Environmental Research Institute to develop AIM/KOREA SULFUR model for simulation. In the study, a base scenario, which is BAU(Business As Usual) scenario, and mitigation scenarios(a use of low-sulfur contain fuel, fuel conversion to cleaner energy, an induction of desulfurization systems, and energy saving) were employed. The results of the simulation are summarized below: The sulphur dioxide emission from the steel industry in 1992 was estimated to be 252,000 metric tons; however, according to BAU scenario, sulphur dioxide emission is expected to be increased to 586,000 metric tons, which is 2.3 times greater than that in 1992 by year 2020. To alleviate such increasement, simulation results under various 7scenarios proved that some degrees of reduction may be possible by an induction of desulfurization systems although there may be numerous ways to interpretate the simulation results; however, the bottom line is that it appears to be difficult to achieve the Korean Ministry of Environment's policy goal-a mitigation of sulphur dioxide concentration to 0.01ppm.

• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.461-467
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• 2009

This paper provides two case studies of environmental impacts with socio-economic values. The first case is on flood protection levees conducted from 2003 to 2004 in Phu Tan district, An Giang province. The impacts were found by comparing full flood protection levees area (FFPL) to non-full flood protection levees area (NFFPL). Participatory Rural Appraisal (PRA) tools per each group of rich, middle, and poor people were used to list the impacts. Then, major impacts were selected by ranking and interviewing 60 households per site, and assessed by Cost Benefit Analysis (CBA) in rice production from 1996 to 2002 between two areas. The tested research indicated moving system of NFFPL to that of FFPL lost about 11 million VND/ha/year. The second case is on impacts of Penaeid shrimp farming conducted in Duyen Hai District, Tra Vinh Province in 2004-2005. Ninety households and 12 local officials were interviewed. Four PRAs were conducted and 36 water samples were taken inside and outside shrimp pond to measure values of DO, COD, Fe total, TSS, N-$NO_3{^-}$, N-$NH_4{^+}$, P-$PO{_4}^{3-}$, and Chlorophyll-a. Research results showed only 36.7% of the households got profit from shrimp farming. Highest financial efficiency was 0.72 for the semi-intensive system. Tested water indicators showed surface water quality did not match Vietnamese standard for surface water in coastal area (TCVN 5943-1995) and in rain. The water was very muddy and contaminated by organic aluminum. Summarily, the impacts were clarified more obviously via adding socio-economic values to assessment. Importantly, the values were transformed to household's income which is an indicator for policy-makers to consider the impacts obviously. Besides, data of different group of people impacted are cases contributing to consideration of the impacts in an appropriate social level.

• Korean Security Journal
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• no.60
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• pp.91-111
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• 2019

Violent crimes have increased continuously due to the development of urban society and have become a threatening factor against the residential safety of citizens. The prevention of these crimes is always a major topic in human society and one of the fundamental elements of the quality of life and safety of citizens. In recent years, much attention has been paid to environmental design through the Crime Prevention Through Environmental Design (CPTED) as a preventive measure. Currently, South Korea is promoting the openness and utilization of public data, and crime prevention is one of the fields that can utilize public data actively. This approach to crime prevention utilizing public data will be helpful for the proposal of policies from new viewpoints departing from the general utilization measures of CPTED that improve streetlights and closed-circuit television (CCTV) installations, whose limitations have been pointed out as they are only mechanical surveillance. Thus, this study sets the research scope based on the statistics of the status of five criminal offenses by administrative district in recent years provided by the data portal in Seoul City, the capital of South Korea, as the utilization data and concentrates on the analysis. Based on the analysis results, this study proposes a method to utilize classical music as a new policy for regions where the improvements are most needed. The open-source Python analysis program was employed as the main data analysis and visualization method.

• The Korean Journal of Applied Statistics
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• v.26 no.1
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• pp.119-130
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• 2013

A system with $n$ components which functions when at least ${\kappa}$ of the components function is called ${\kappa}$-out-of-$n$ system. Most studies on ${\kappa}$-out-of-$n$ system derive the system reliability based on the assumption that the system has just two states: functioning or failed. However, the system efficiency may depend on the number of functioning components. This paper considers a Multi-state ${\kappa}$-out-of-$n$ system and derives the total system efficiency. In addition, assuming that the system is repairable, the optimal repair policy to maximize the system efficiency is studied. The system efficiency considered in this paper can be regarded as a generalized measure of the mean time to the failure of the system.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.41-53
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• 2009

For 5 years and 6 months, ranging from January 2003 to June 2008, SPSS 12.0 Statistical Program was used to analyze the overall analysis, analysis of center line encroachment, analysis of signal violations, analysis of drinking while intoxicated, analysis of driving without license, analysis of two-wheel vehicle, analysis of pedestrian, analysis of safety equipment, analysis of traffic publicity or education and automobile registration accounts, and casualty of traffic accidents that are determined as having statistical implication based on the statistics available from the policy to take a look at traffic accident in the Daejeon area, and there were some meaningful results. With the proof that there is a certain level of ratio for the correlations between traffic control and traffic accident that the effect of traffic control has shown with certain time interval. The relationship of traffic control and the casualty of traffic accident has very low coefficient of correlations that it is not statistically noticeable that traffic control of the police has almost no effect in preventing traffic accident. This is a display of the fact that the conversion of direction for traffic safety measure undertaken to this point is rather urgent that there is a dire need of establishing the effective alternatives.

• Journal of Technology Innovation
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• v.23 no.1
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• pp.87-105
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• 2015

This research confirms a non-linear relationship between R&D investment and performance of small and medium-sized enterprises and measures the adequate level as threshold value. Although previous studies did not consider the time lag and estimated indirectly the level using the R&D investment squared term, this study assumes 2 years time lag and uses the threshold estimation model to measure directly. We find that there is the S-curve relationship between the profit rate as R&D output and R&D intensity and the ratio of researchers to employees as R&D input. Also, we estimate the adequate levels of R&D investment, 6.4% for R&D intensity and 13% for the ratio of researchers to employees. This relationship and measurement of the level can offer basic facts and implications about R&D policy and strategy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.1
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• pp.103-112
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• 2018

To improve current transportation service, a new Seoul Metropolitan Transportation Administration (Seoul MTA), backed by Korean central government, is on the way of being established. This paper tries to answer questions such as 'What is the best type of organizational formation of the upcoming institute to deliver better, seamless transportation service?' and 'What is the most suitable scope of work of the upcoming institute to achieve the goal?' A group decision making process, a kind of AHP (Analytic Hierarchy Process) was adopted to measure the experts' preferences of alternatives in quantitative scale measurement. To evaluate the alternatives, five evaluation criteria were selected. Among them, it is revealed that 'Improvement of the transportation service' and 'Political & Administrative power to make it happen' are the two most important evaluation criteria over what types or operating costs of the administrations are. When the five evaluation criteria are applied onto the group of alternatives, it yields that a stand-alone organization, which should be independent from upper-level government body, should have an integrated and sole authority on the area-wide transportation system management.

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.915-961
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• 2010

This study is concerned with health damages from $SO_2$ under different assumptions on the relationship between air concentrations and their marginal health impacts. $SO_2$ concentration profiles resulting under emission caps, and a system of tradable emission allowances are compared. Using slopes and curvatures of the health response function consistent with evidence in medical literature, emission caps are shown to lead to lower aggregate damages under all considered parameters, an advantage of $26~452 million. The benefit of emission caps over tradable allowances increases with the curvature of the response function, but falls with its slope. The advantage of emission caps in terms of environmental damages is never overturned completely for the considered functional forms. The marginal damage function would have to be steeper than what the current medical evidence suggests for price instruments to outperform emission caps in terms of aggregate damages. With other welfare consequences included-emission abatement costs, consumer and producer surpluses, and government revenue-emission caps always lead to a $3.7~4.1 billion greater measure of social welfare.

• Journal of KIISE:Software and Applications
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• v.34 no.6
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• pp.572-583
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• 2007

This paper investigates Centering-based metrics to evaluate ordering of utterances for text structuring. We point out a problem of MIN.NOCB metric which has been regarded as the simplest and best measure to evaluate coherence of ordering within Centering framework, and propose a new Centering-based metric, MAX.CPS as an alternative or supplementary one. This paper introduces a framework which pre-estimates the effectiveness of a metric on a given input ordering, and selects an applicable metric according to the pre-estimation result. Using this framework, we propose a new policy which can generate more optimal ordering within Centering framework. Moreover, we evaluate several kinds of Cf-ranking methods in terms of Centering-based metrics, and find that simply ranking entities by their linear order is generally the most suitable because of characteristics in Korean.