• KDI Journal of Economic Policy
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• v.28 no.1
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• pp.117-144
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• 2006

This study is to analyze the existence of the real buffer effect that reflects the effect of beginning-of-period inventory stocks effect on the demand for fixed investment, and the financial buffer effect indicates the substitution effect between end-of-period inventory stock and the source of financing for fixed investment. I use panel data of 361 Korean listed non-financial firms during 1990-2003. After the crisis, it also observed whether the relationship between inventory stocks and fixed investment has altered or not. I review the theoretical connection between inventory stock and fixed investment through the paper by Bo(2004) and estimate the investment model by the method of GMM-SYS. The results show negative relation between end-of-period inventory stock and fixed investment in the whole period and each period classified, also it confirms that the relation between fixed investment and end-of-period investment is significantly negative. It can be interpreted through two aspects that firms not only use inventory stock as a buffer in response to unexpectedly high demand, but also utilize inventory stock as a source of financing for fixed investment. The results imply that firm's decision-making is much correlated with production-and-inventory stock adjustment, decision-making about fixed investment, and decision-making about financial affairs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.401-412
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• 2003

In this paper, a broadband phase shifter structure using a new switched network was proposed. A new reference network is composed of coupled lines and 45$^{\circ}$open and short stubs, which are shunted at the edge points of a main line, respectively, A delay network is composed of only a standard transmission line. It is possible to design a broadband 180$^{\circ}$phase shifter that phase dispersive characteristics by an impedance ratio R of coupled lines and greater phase dispersive characteristics by characteristic impedances Zm, Zs of a main line and stubs are used together. By considering a structure symmetry, the even and odd mode analysis was performed to obtain theoretical S-parameters of the proposed phase shifter. Also, through computer simulation on the basis of derived equations, design graphs were presented to optimally design a 180$^{\circ}$broadband phase shifter. Design graphs provide the values of characteristic impedances Zm, Zs, and I/O match and phase bandwidths. To verify electrical performances of the broadband phase shifter proposed in this paper, low different 180$^{\circ}$phase shifters, operated at the center frequency 3 GHz were designed and fabricated using design graphs, and were experimented. One of them was designed as a standard Schiffman structure to compare with electrical performances. Measured results of each phase shifter to satisfy simultaneously design conditions of I/O match （VSWR=1.15:1) and maximum phase deviation $({\varepsilon}_{{\Delta}{\phi}}＝{\pm}2^{\circ})$ were well in agreement with corresponding simulation results over impedance match and phase error bandwidths, and showed broadband characteristics.

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.78-83
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• 2003

본 연구에서는 건설CALS/EC 기반의 정보화 추진을 위한 정보시스템을 개발할 때 적용되는 기존의 소프트웨어 개발방법론의 문제점을 분석하고, 표준화되지 않은 개발방법론의 적용으로 시스템 개발에 비효율적인 비용을 투자하는 문제점과 특성상 입찰, 구매, 계약 등 분야별로 상이한 기능의 업무에 따라 구축되는 건설산업 정보화에 있어서 상호간에 데이터 및 프로세스를 원활히 통합하지 못하므로 인하여 발생되는 개발의 중복성, 정보 활용의 비효율성 등의 문제점을 개선하고자 하였다. 이를 위하여 최근 새로이 부각되고 있는 방법론인 컴포넌트 기반 개발방법론(CBD: Component-Based Development)을 사용하여 건선CALS/EC 표준지침 웹서비스를 위한 시스템의 업무프로세스를 모델링하여 사용자가 쉽게 재사용가능하고 타업무분야에 확대 가능한 방향을 제시하였다. 본 연구를 위하여 기존의 소프트웨어 개발 방법론의 적용상 문제점 분석을 통하여 컴포넌트 기반 개발방법론의 필요성을 증명하고 비즈니스 컴포넌트 프레임워크를 사용하여 건설 CALS/EC 표준지침 웹서비스의 업무프로세스에 적용할 기술적인 방법론을 고찰하고 업무에 효과적으로 적용할 수 있는 업무프로세스 컴포넌트를 제시하였다. 본 연구에서 도출된 컴포넌트 모델은 향후 타업무분야의 시스템을 개발할 때 사용자요구분석 단계부터 별도의 재 작업이 없이 사용될 수 있으며 시스템을 구현할 때 개발 모듈의 중복방지와 용이한 비즈니스로직의 변경 등이 가능하며, 추가의 업무 프로세스나 연관된 다른 분야의 업무프로세스의 반영 및 추가 시 컴포넌트의 활동모델을 쉽게 수정하여 정의함으로써 쉽게 시스템의 기능을 확장할 수 있다.LE 산정에 관한 지속적인 실험적 연구가 이루어져야 하겠다. 증가할 것이다. 또한 부분육을 이용한 완전제품, 적색육제품, 유기농이나 별미식 제품과 같은 형태의 다양한 포장육 제품이 도입 될 것으로 생각되어진다.e in vitro SPF test method will be able to be used as an alternative method for in vivo SPF in case of lotion and cream. replica. A statistically significant improvement of Star Fruit Leaf Extract BG30-treated site was seen in decreased wrinkles. Star Fruit Leaf Extract BG30 results in clinically visible improvement in wrinkling when used topically for 5 weeks. 또한 관계마케팅, CRM 등의 이론적 배경이 되고 있는 신뢰와 결속의 중요성이 재확인하는 결과도 의의라고 할 수 있다. 그리고 신뢰는 양사 간의 상호관계에서 조성될 수 있는 특성을 가진 반면, 결속은 계약관계 초기단계에서 성문화하고 규정화 할 수 있는 변수의 성격이 강하다고 할 수가 있다. 본 연구는 복잡한 기업간 관계를 지나치게 협력적 측면에서만 규명했기 때문에 많은 측면을 간과할 가능성이 있다. 또한 방법론적으로 일방향의 시각만을 고려했고, 횡단적 조사를 통하고 국내의 한 서비스제공업체와 관련이 있는 컨텐츠 공급파트너만의 시각을 검증했기 때문에 해석에서 유의할 필요가 있다. 또한 타당성확보 노력을 기하였지만 측정도구

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.94-104
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• 2017

With the recent increasing interest in preventive medicine, observation has been made regarding the positive relationship between a routinized place that includes activity and health improvement. This study evaluates the effective value of a designed landscape for seeing a healing environment and sees the difference of the effective value of classified physical settings regarding Evidence Based Design. Therefore, the study evaluates the perceived restorativeness scale of Cheonggyceheon's 1.5km section and five type settings in the same section regarding how much it works as a healthy urban park. The research methodology used to study sub-settings' and the research site's restoration effects was observation and questionnaires. A PRS (Perceived Restorativeness Scale) questionnaire survey was the research tool employed. The study drew two major results. Firstly, PRS 6.12 is the score of the whole research site, so the study identifies that Cheonggycheon has a mental fatigue restoration function. Secondly, the sub-setting named 'Near Sidewall' was the most attention restorative, according to the ANOVA results. In conclusion, this study suggests significant information support regarding the reasons for creating green areas in urban settings by identifying a particular designed healing sit.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.2
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• pp.169-177
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• 2017

In this paper, classification of spall and crack faults of gear teeth is studied by applying the ensemble empirical mode decomposition(EEMD) for the gear transmission error(TE). Finite element models of the gears with the two faults are built, and TE is obtained by simulation of the gears under loaded contact. EEMD is applied to the residuals of the TE which are the difference between the normal and faulty signal. From the result, the difference of spall and crack faults are clearly identified by the intrinsic mode functions(IMF). A simple test bed is installed to illustrate the approach, which consists of motor, brake and a pair of spur gears. Two gears are employed to obtain the TE for the normal, spalled, and cracked gears, and the type of the faults are separated by the same EEMD application process. In order to quantify the results, crest factors are applied to each IMF. Characteristics of spall and crack are well represented by the crest factors of the first and the third IMF, which are used as the feature signals. The classification is carried out using the Bayes decision theory using the feature signals acquired through the experiments.

• Informatization Policy
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• v.19 no.1
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• pp.74-90
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• 2012

This thesis analyzes the Apple Inc.'s case from the viewpoint of the necessity for the protection of information privacy related to location data as for information society and ubiquitous community. Meanwhile, the regulatory conformity to equilibrium of contradictional value between personal data protection and utilization of information is debated from the fundamental right as for constitutional law concept to the commercial and technological structure in terms of economic and business point. Therefore, this paper reaches the conclusion that the legislative system should form a harmonious relationship between legal protection and lawful utilization to reappraise the present condition of legalization on personal data protection from guaranteeing rights and interests of information subject in the perspective of human rights to information guarantee consequently. As a result, it is required to revaluate the lawfulness of the fine on the violation of administrative duty levied by KCC(Korea Communications Commission).

• Membrane Journal
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• v.17 no.4
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• pp.287-293
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• 2007

Pervaporation separation of toluene from water were studied using hydrophobic copolyimide membranes. The copolyimide membranes were prepared from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and two diamines (polysiloxane diamine (SIDA)/2-(perfluorohexyl) ethyl-3,5-diaminobenzene (PFDAB)). The pervaporation properties for toluene/water were investigated in terms of mol ratio of SIDA/PFDAB in polyimide membranes. Sorption- and diffusion-related properties were measured to analyze the permeation properties in solution-diffusion theory, It was found that as the SIDA content in the membranes increased, sorption of toluene and sorption selectivity of toluene/water increased due to high affinity of siloxane moiety toward toluene. Diffusion coefficient of toluene and diffusion selectivity of toluene/water also increased with SIDA content due to high free volume of siloxane moiety. As the results, the permeation flux and pervaporation selectivity increased markedly from 0.005 $kg/m^2h$ to 049 $kg/m^2h$ and from 9 to 6380, respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.59-66
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• 2016

The 2011 debris flow in Mt. Umyeonsan in Seoul, South Korea caused significant damages to the surrounding urban area, unlike other similar incidents reported to have occurred in the past in the country's mountainous regions. Accordingly, landslides and debris flows cause damage in various surroundings, regardless of mountainous area and urban area, at a great speed and with enormous impact. Hence, many researchers attempted to forecast the extent of impact of debris flows to help minimize the damage. The most fundamental part in forecasting the impact extent of debris flow is to understand the debris flow behavior and sedimentation mechanism in complex three-dimensional topography. To understand sedimentation mechanism, in particular, it is necessary to calculate the amount of energy and erosion according to debris flow behavior. The previously developed debris flow models, however, are limited in their ability to calculate the erosion amount of debris flow. This study calculated the extent of damage caused by a massive debris flow that occurred in 2011 in Seoul's urban area adjacent to Mt. Umyeonsan by using DEM, created from aerial photography and airborne LiDAR data, for both before and after the damage; and developed and compared a debris flow behavioral analysis model that can assess the amount of erosion based on energy theory. In addition, simulations using the existing debris flow model (RWM, Debris 2D) and a comprehensive comparison of debris flow-stricken areas were performed in the same study area.

• Environmental and Resource Economics Review
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• v.29 no.2
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• pp.113-144
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• 2020

Throughout various data sources, it is widely observed that air quality in South Korea has become improved. Koreans, however, insist that their health status and economic burden due to worsened air quality get degenerated. This study aims to explain the mismatch between perception and measured data, air pollution-led medical expenses, and consumption behaviors in the economics perspectives. First, we demonstrated data-driven evidence of mismatch in the perceived severity of air pollution and its enhancement in measured data. Second, using the health demand model, we theoretically derived and empirically showed a co-rising relation between air pollution severity and medical expenses. Last, we analyzed that the perception led to increased defensive expenditures in consumption. This result implies the possibility of overestimation in air pollution impacts on socioeconomic losses and its possible reverse interpretation from increased social benefit after improved air quality. Our results recommend policy consideration to strengthen air quality standards, to support socially vulnerable groups regarding defensive expenditures, and to improve the accessibility and credibility of air pollution information.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.699-712
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• 2000

Juam lake is a major water resource for the industrial and agricultural activities as well as the resident life of Kwangju and Chonnam regions. However, the water quality of the lake is getting worse due to a large quantity of pollutant inflowing to the lake. Thus, the strategy for achieving the water quality goal of the lake should be developed as soon as possible. When there are various alternatives that can be used as the strategy, several criteria based on the achievement degree of water quality goal, the applicability of technique and social environment, and the reasonableness of the cost required are made to evaluate and rank the alternatives. However, it is difficult to make a decision when there are multiple criteria and conflicting objectives and specifically the estimated values of criteria contain elements of uncertainty. The uncertainty stems from the lack of available information, the randomness of future situation, and the incomplete knowledge of expert. As the degree of uncertainty is higher, the decision becomes more difficult. In this study, a fuzzy decision-making method is presented to assist decision makers in evaluating various alternatives under uncertainty. The method allows decision makers to characterize the associated uncertainty by applying fuzzy theory and incorporate the uncertainty directly into the decision making process for selecting the "best" alternative so decisions can be made that are more appropriate and realistic than those made without taking uncertainty in account.