• 한국입자에어로졸학회지
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• 제10권1호
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• pp.9-17
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• 2014

Several studies have been carried out on the source contribution of the particulate Polycyclic Aromatic Hydrocarbons (PAHs) over Seoul by using the Chemical Mass Balance Model (CMB)(Lee and Kim, 2007; Kim et al., 2013). To confirm the validity of the modeling results, the modified model employing a photochemical loss rate along with varying residence times and the standard model that considers no loss were compared. It was found that by considering the photochemical loss rate, a better performance was obtained as compared to those obtained from the standard model in the CMB calculation. The modified model estimated higher contributions from coke oven, transportation, and biomass burning by 4 to 8%. However, the order of the relative importance of major sources was not changed, coke oven followed by transportation and biomass burning. Thus, it was concluded that the standard CMB model results are reliable for identifying the relative importance of major sources.

• 한국조경학회지
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• 제29권3호
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• pp.29-37
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• 2001

The purpose of this study is to determine the suitable illuminance model of an urban neighborhood park. To this end, 1 dependent variable and 11 independent variables were set, and multiple regression analysis was applied to find correlation between variables and the model. The results of this study are as follows; 1) Among 11 independent variables abstracted to study suitable illuminance model of an urban neighborhood park, as a result of analysis on correlation between suitable illuminance of a dependent variable and activity space by using dummy variables, activity type and illuminance by spaces the suitable illuminance required for an urban neighborhood park was much influenced by activity type, and the fact that the activity was not limited to a specific space. 2) As a result of multiple regression analysis, independent variables influencing the suitable illuminance model of an urban neighborhood park were activity space, illuminance by spaces, seated activity, standing activity, and sporting activity. And, for relative contribution of independent variables to suitable illuminance, activity with sporting showed an importance 22 times higher than seated activity. When the central square(Sp_1) of activity spaces was set to reference category using dummy variables, it showed a contribution 52 times higher than sorting space(Sp_7) and the central square as the most important variable. 3) It was analyzed that suitable illuminance of an urban neighborhood part was most influenced by sporting activity but the relative contribution of a sporting space where activity with sporting occurs was least in view of the function of the space. Very high illuminance is required to accept high activity, and if illuminance at a certain space becomes too high, it may influence the illuminance of other spaces, and may consequently have a negative effect on the suitable illuminance of an urban neighborhood park. The results of this study were mainly for teenagers and young adults in their twenties, so further concrete studies which consider gender and a wider age range are needed in the future. Based on subsequent study, suitable illuminance by spaces shall be suggested.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.84-92
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• 1997

Among the various sources of vehicle interior noise, this paper concerns the road induced noise ; the identification of its transfer path by using experimental method. Multiple input and single output model is taken as a noise generation model. Because it is impossible to measure the road imput forces directly, the acceleration signals are measured on four axle;three directions for each point. By considering the cross correlations of input signals, four uncorrelated source groups are taken. Multiple coherence function is employed to investigate the contribution of each group. In addtion, to identify the detailed path through the suspension systems, the contributions of all possible paths are ranked by using the coherence functions between interior noise and the relative accelerations of connections such as bushings and mountings. Measurements are performed with passenger vehicle traveling on concrete and asphalt roads at 60㎞/h.

• 한국경영과학회지
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• 제28권1호
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• pp.63-77
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• 2003

Group buying is one of the most popular transaction patterns on the internet at least in Korea. Nevertheless, it is hard to find academic researches for it in view of consumer behavior. In this paper, we analyze factors which determine consumer's attitude toward and intention of participation in Internet group buying by comparison of Internet individual one. For this purpose, we propose “lowering price”, “decreasing risk” and “reducing transaction cost” as relative advantages and "lack of product assortment" and "delay of time" as relative disadvantages over individual buying on the Internet. For empirical test, Internet users who have some experiences of individual buying but not group ones on the Internet are surveyed and analyzed. In result, a satisfying model fitness for structural equation model is derived and most hypotheses except the relationship between "decreasing risk" and "attitude toward Internet group buying" are accepted. Our results provide not only academic contribution by suggestion of a research framework but also practical insight by discussion of diverse features in Internet group buying.verse features in Internet group buying.

• Journal of Forest and Environmental Science
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• 제30권3호
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• pp.259-266
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• 2014

Stand Density Diagrams (SDD) are average stand-level models which graphically illustrate the relationship between yield, density and mortality throughout the various stages of forest development. These are useful tools for designing, displaying and evaluating alternative density regimes in even-aged forest ecosystems to achieve a desired future condition. This contribution presents an example of a SDD that has been constructed for teak forests of Karnataka in southern India. The relationship between stand density, dominant height, quadratic mean diameter, relative spacing and stand volume is represented in one graph. The relative spacing index was used to characterize the population density. Two equations were fitted simultaneously to the data collected from 27 sample plots measured annually for three years: one relates quadratic mean diameter with stand density and dominant height while the other relates total stand volume with quadratic mean diameter, stand density and dominant height.

• 한국경제지리학회지
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• 제4권2호
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• pp.57-77
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• 2001

이 논문은 1인당 GRDP와 노동생산성의 몇 가지 요소분해를 통해 1990년대 우리나라 지역격차의 추이와 대표적 낙후지역중의 하나인 호남지역의 전국대비 상대적 경제성과 패턴을 조사하였다. 이로부터 몇 가지 사실들을 발견할 수 있었다. 첫째, 1990년대 우리나라 지역간 격차가 심화되는 추세에 있으며 이는 지역간 취업률 격차보다는 생산성 격차에 기인하는 바가 크다. 둘째, 1 인당 GRDP의 측면에서 보면 전국대비 호남지역경제의 성과가 저조하다. 단 전남지역은 예외적이다. 하지만 이것은 상대적 누적인구성장이 높은 음(-)의 값을 갖기 때문이다. 세번째, 호남지역의 낮은 상대적 생산성 성장은 건설업, 운수창고업, 그리고 제조업에서의 상대적인 생산성 성장의 하락에 기인하는 바가 크다. 한편, 전남지역에서는 제조업이 상대적 지역생산성 성장에 긍정적인 기여를 하였다. 마지막으로 농림어업과 도소매업 및 음식숙박업을 제외한 서비스업종이 상대적 지역생산성의 마이너스 성장에 제동을 걸었다. 특히 호남지역 전체에서 사회, 개인, 공공 및 기타서비스업으로의 고용의 이동은 주목할 만하다. 낙후지역경제에서 서비스업의 역할이 중요하다는 것을 위의 사실로부터 추론할 수가 있을 것 갈다. 물론 제조업 투자를 통해 지역경 제의 생산성을 높일 수 있지만, 순환누적인과 모형이 함의하는 것처럼, 이는 상당한 시간이 소오 되는 일이다. 다양한 서비스업종 중에서 사회, 개인, 공공 및 기타서비스업은 주목의 대상이 된 다. 왜냐하면, 낙후지역에서 인구성장이 감소하는 추세이기 때문에 인구규모에 비례하는 도소매 업과 음식숙박업과 같은 소비자서비스업의 성장은 제한적일 수 있다. 따라서 공공부문의 재정보 조와 지원의 매개가 여전히 낙후지역 경제발전에 중요한 고리일 수밖에 없는 현실에서, 사회, 개 인, 공공 및 기타서비스업은 공공행정, 사회보장, 교육, 보건, 사회복지사업 등을 포괄하고 때문에 그 중요성이 부각될 수가 있을 것 같다.

• 품질경영학회지
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• 제49권1호
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• pp.61-79
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• 2021

Purpose: The purpose of this study is to study the relative weights of Quality Scorecard (QSC) which was developed for a new quality concept, called Open Quality, in the era of Industry 4.0. Open Quality aims to ensure quality responsibility by accurately measuring the quality level and sharing the quality data with stakeholders. Methods: To analyze the importance of QSC, a survey study was conducted based on 10 types of industry. The relative weights of QSC measures are investigated by both the industry types and the organizational life cycle. Further, the relative importance of QSC was analyzed according to the organization's lifecycle. By dividing the aspects with respect to the result data, application method for QSC is further provided. Results: The result indicates that there are significant differences among Korean companies in terms of the level of Industry revolution stages. Among ten industry types, manufacturing and finance sectors show the highest importance of QSC. QSC measures are also considered more importance in growth stage of the maturity cycle than generator and decline stages. Conclusion: When QSC is adopted for Open Quality, its relative weights must be considered to cope with the unique characteristics of industrial types. Besides, QSC's contribution may vary according to the level of maturity of the target company.

• Korean Chemical Engineering Research
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• 제54권1호
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• pp.22-35
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• 2016

본 연구에서는 CALPUFF 모델링을 수행하여 구미국가산업단지 공단지역에 악취로 인한 주민의 민원이 빈번한 지역과 아세트알데히드 배출 주요 점오염원인 구미국가산업단지 공단지역 합성섬유제조업체 악취배출시설과의 상관관계를 정립하고자 하였다. 본 연구의 CALPUFF 모델링 결과로서 T사 배출설비 개선 후에 구미공단의 아세트알데히드 농도의 최대값이 T사 배출설비 개선 전보다 O ($10^{-5}g/m^3$)에서 O ($10^{-6}g/m^3$)으로 저감되고 겨울(1월)과 봄(4월)에 구미 1공단의 아세트알데히드 농도가 개선되어서 구미 3공단에서 자주 아세트알데히드 농도의 구미공단 내 최대값이 도출되었다. 또한 T사 배출설비 개선 후에 도출된 아세트알데히드 농도의 구미공단 내 최대값 예측범위는 T사 배출설비 개선 전의 구미공단 내 최대값 예측범위보다 개선되었다. 이와 같은 총괄 점오염원의 아세트알데히드 기여도 평가 예측을 위한 CALPUFF 모델링 최대값은 '구미대구지역 HAPs 조사연구'의 측정 최대값 결과와 비교하였을 때에 상호 비교할 수 있는 비슷한 값을 보였고 민원추세와도 잘 일치하였다. 따라서 본 연구에서 총괄 점오염원의 아세트알데히드 기여도 평가 예측에 대한 유효성을 보여주었다. 한편 총괄 점오염원에서의 아세트알데히드 배출에 의하여 확산된 아세트알데히드 농도에 대한 T사 점오염원의 상대적 기여도가 T사 배출설비 개선 후에 개선 전보다 대부분 배 이상 낮아짐이 예측되었다. 반면에 이에 대한 W사 점오염원의 상대적 기여도는 T사 배출설비 개선 후가 T사 배출설비 개선 전보다 배 이상 증가하였다. 이것은 T사 배출설비 개선에 의하여 상대적으로 W사 점오염원의 아세트알데히드 기여도가 커졌음을 의미하였다.

• 한국운동역학회지
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• 제17권4호
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• pp.27-36
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• 2007

The purpose of this study was to investigate the effect of the upper body in order to increase a propulsive force in the old's walking. The subjects were each 10 males, the latter term of the aged and former term of the aged. There were three walking speeds of slow(about 5km/h), medium(about 6km/h), and maximum speed(about 7km/h). The subjects walking 11m were filmed the 5m section (from 3m to 8m) by 2-video cameras using three dimensional cinematography. And we computed different mechanical quantities and especially computed the relative momentum in order to achieve this study's aim. In this study, we was able to acquire some knowledge. The step length and step frequency increased in proportion to the walking speed, and the faster walking speed, the shorter ratio of supporting time( both legs supporting time/one step length time). When it was one leg support phase, the torso was indicated to generate the momentum in order to produce the propulsive force of walking. The upper and lower body had a cooperative relation for walking such as keeping step rate with the arms to legs and maintaining the body balance. The opposition phase for upward-and-downward direction of the torso and arms in walking was functioned to prevent the increase rapidly toward vertical direction of the center of gravity. The arms had contributed to coordinate the tempo of legs and the posture maintenance of the upper body. And by absorbing the relative momentum from the upper torso with arms to the lower torso, it had the rhythmical movement on upward-and-downward direction reducing the vertical reaction force. On account of the relations of absorption and generation of the propulsive force and the production of vertical impulse in the lower torso when walking by maximum speed, it was showed that the function of lower torso was come up as important problem for the mechanical posture stability and propulsive force coordination.

• 한국수자원학회논문집
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• 제42권11호
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• pp.897-909
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• 2009

본 연구에서는 지리정보체계(GIS)의 격자 기반 GIUH 모형을 이용하여 배수경로의 이질성에 따른 지표면 유동과 하천망 유동의 상대적 기여도를 정량적으로 평가하였다. 대상유역은 국제수문개발계획(IHP)의 평창강, 보청천 및 위천 유역의 17개 소유역을 선정하였다. 각 대상유역에 대해 지표면과 하천의 배수경로길이에 대한 평균과 분산을 추정-분석하였다. 또한 관측 수문사상과 결합하여 GIUH 모형의 동적매개변수인 특성 유속을 지표면과 하천에 대해 산정하였다. 산정된 경로길이와 특성유속을 통해 유하시간의 분포, 즉 순간단위도의 평균 및 분산을 추정하여 배수경로의 이질성에 따른 각각의 기여도를 평가 하였다. 연구 결과 순간단위도의 형상을 결정하는 분산의 영향은 중소규모 유역(500 $km^2$이내)에서 지표면의 영향이 지배적이었다. 따라서 소규모 유역에서 GIUH 적용 시 지표면의 유동을 중요하게 고려해야 할 것이다.