• 제목/요약/키워드: Substance-field model analysis

검색결과 6건 처리시간 0.019초

바람장의 공간적.시간적 해상도가 누출물질 확산에 미치는 영향 (Effects of Spatio-Temporal Resolution of Diagnostic Wind Field on the Dispersion of Released Substance)

  • 김영성
    • 한국대기환경학회지
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    • 제16권4호
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    • pp.327-338
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    • 2000
  • complexity in atmospheric environment coupled with shoreline and complex terrain often causes local variations of meteorology that are distinct from those representative over larger surrounding area, These kinds of local variations are less significant in usual long-term environmental impact analyses dealing with continuous plume. The variations could however be crucial in predicting dispersion of toxic substance released in a relatively small area for a short duration. In the present paper the effects of spatial and temporal resolution of diagnostic wind field on the dispersion of the released substance are investigated by using a puff model. A hypothetical release scenario assumes that a substance is released from a location in the Yochon Industrial Estate and passively dispersed within a few-kilometer distance for an hour. The results show that diagnostic analysis could resolve more spatial variations to some extent by employing smaller grid size. The peak concentrations and puff trajectories obtained from spatially -and/or tmeporally -varing diagnostic wind field are found appreciably different from those obtained from uniform wind field. Attention to high-resolution wind field in the both spatial and temporal spaces is called in the consequence analysis of toxic substance release.

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카본 세라믹 복합재 디스크의 벤트 구조 최적화를 통한 냉각성능 향상에 관한 연구 (A Study on Improvement of Cooling Performance through Vent Structure Optimization of Carbon Ceramic Composite Disc)

  • 심재훈;신웅희;이중희;전갑배;김병철;곽정후;임동원;현은재;전태형;이재만
    • 자동차안전학회지
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    • 제11권1호
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    • pp.23-29
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    • 2019
  • Recently, use of composite materials has been increasing for body structures and chassis parts in the car industry because of weight reduction effect and excellent mechanical thermal characteristics. However, application of composite materials in brake system is very difficult because it is hard to obtain enough brake performance due to low heat storage capacity of the composite materials. In this paper, we will present new carbon ceramic composite disc with high flow characteristic. To obtain this characteristic, new vent structures were designed by using ARIZ method and substance-field model analysis. The flow effect of these vent structures on the brake performance was verified by pugh matrix and cooling test. The test results show improvement of cooling performance up to $30^{\circ}C$. Finally, These results will improve brake the reliability of the brake performance for the high performance vehicles and electric vehicles.

Analysis of Electromotive Force Characteristics for Electromagnetic Energy Harvester using Ferrofluid

  • Kim, Young Sun
    • Journal of Magnetics
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    • 제20권3호
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    • pp.252-257
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    • 2015
  • This paper investigates the concept and implementation of an energy harvesting device using a ferrofluid sloshing movement to generate an electromotive force (EMF). Ferrofluids are often applied to energy harvesting devices because they have both magnetic properties and fluidity, and they behave similarly to a soft ferromagnetic substance. In addition, a ferrofluid can change its shape freely and generate an EMF from small vibrations. The existing energy harvesting techniques, for example those using piezoelectric and thermoelectric devices, generate minimal electric power, as low as a few micro-watts. Through flow analysis of ferrofluids and examination of the magnetic circuit characteristics of the resultant electromagnetic system, an energy harvester model based on an electromagnetic field generated by a ferrofluid is developed and proposed. The feasibility of the proposed scheme is demonstrated and its EMF characteristics are discussed based on experimental data.

한국기업(韓國企業)의 해외직접투자(海外直接投資) 결정요인형태(決定要因形態)에 관한 실증(實證) 연구(硏究) (An Empirical Study on the Determinants and Effects of Korean FDI in Manufacturing Industries)

  • 이응권
    • 무역상무연구
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    • 제27권
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    • pp.183-213
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    • 2005
  • This study is achieving overseas investment to be kept and manages important position in business scope because Korean Company achieves business in major market in world and goes forward. under proposition that development(foreign direct investment) previous engagement can not but differ with advanced nation enterprise's model in over sea direct investment achievement. Grasp ramification(pattern change substance) of overseas direct investment since the 1990 to korean manufacture Firm(enterprise). Seek political consultation by analyzing change of factor and investment decision factor by year in dimension by industry investment winter season by year affecting in oversea direct investment and was attained in purpose to verify existent theory's explanation power connected with investment previous engagement. This is that can develop and procure competitive advantage of enterprise peculiarity by making overseas direct investment adversely with existent theory that can make foreign country direct investment though there is high position of enterprise characteristic's competitive advantage and move of knowledge and information is important in korean firm's overseas direct investment in globalization roadbed in at least own field through change and renovation establish experiment model under proposition that should grope more active previous engagement than advanced nation enterprise and arranged subject of study if it is korean's firm that wish to become universal guidance enterprise. and examine trend of direct investment and actual conditions invested first in the foreign countries as examples by investment department, by investment industry inside of investment scale etc..., establish korean firm's invest area selection and decision and investment very important person and effect analysis Circumstance-model that is based in strategic adaptedness by year. Circumstance-variable have influenced how in overseas direct investment and decision and what variable will be considered first in over sea direct investment did Empirical analysis in here after

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토픽모델링을 활용한 조세순응 연구 동향 분석 (Analysis of Research Trends in Tax Compliance using Topic Modeling)

  • 강민조;백평구
    • 한국콘텐츠학회논문지
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    • 제22권1호
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    • pp.99-115
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    • 2022
  • 본 연구의 목적은 사회과학 전반에 걸쳐서 수행되고 있는 조세 분야의 대표적인 연구주제로서 조세순응, 납세의식, 성실납세(이하 "조세순응")에 관한 연구의 흐름을 정리함으로써 융합학문으로서 세무학의 지평을 확장하는 것이다. 이에 조세순응에 관한 국내 학술지 논문을 학제적 관점에서 종합적으로 분석하기 위하여 텍스트마이닝의 일환으로 토픽모델링 기법을 적용하였다. 데이터 수집-키워드 전처리-토픽모델 분석의 흐름으로 총 347편의 논문에 연구자가 등록한 조세순응 관련 키워드들로부터 잠재적인 연구주제를 제시하고자 하였다. 본 연구의 분석 결과로 첫째, 키워드 분석에서는 세무조사, 조세회피, 성실신고확인제도 등의 키워드가 단순 빈도 기준으로 상위 5개 키워드에 포함되었고, 키워드의 상대적 중요도를 감안한 TF-IDF 값에서도 상위 5개 키워드에 포함되었다. 한편 탈세라는 키워드는 단순빈도에서 부각되지 않은 것에 비해 TF-IDF 값 기준으로 상위 키워드에 포함되었다. 둘째, 토픽모델링을 통해 잠재적인 8개의 연구주제를 도출하였다. 해당 주제는 (1) 조세공정성과 조세범칙행위의 억제, (2) 조세법의 이념과 조세정책의 타당성, (3) 실질과세원칙과 조세채권의 담보 (4) 납세협력비용과 세무행정 서비스, (5) 신고납세제도와 세무전문가, (6) 조세풍토와 전략적 조세행동, (7) 조세행동의 다면성과 차별적 순응의도, (8) 과세정보시스템과 효율적 세원관리와 같다. 본 연구는 학문 간의 경계를 넘어 조세순응이라는 주제어를 바라보는 다양한 관점을 포괄적으로 조망함으로써 학제간 소통의 기회를 마련하고 합리적인 조세제도를 구축하는데 실천적 시사점을 제시하고자 하였다.

폐쇄성수면무호흡증 의심환자에서 무호흡저호흡지수에 영향을 주는 임상적 신체적 요인 : 예비연구 (Clinical and Physical Characteristics That Affect Apnea-Hypopnea Index in Suspected Obstructive Sleep Apnea Patients : The Preliminary Study)

  • 강승걸;신승헌;이유진;정주현;강일규;박인숙;김찬우;예미경;황희영;김선태;박기형;김지언
    • 생물정신의학
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    • 제20권2호
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    • pp.54-60
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    • 2013
  • Objectives The purpose of this study is to find the influential clinical and physical characteristics which affect apnea-hypopnea index (AHI) in suspected obstructive sleep apnea (OSA) patients. Methods We evaluated the comprehensive factors including sleep related symptoms, clinical scales, medical history, substance use, and anthropometric data of the 119 participants who complained of the symptoms of OSA. All the participants underwent attended-full night laboratory polysomnography. The correlation and multiple regression analysis were conducted to find the influential and predictive factors of AHI. Results A multiple linear regression model 1 showed that higher AHI was associated with higher body mass index (BMI)(p < 0.001) and higher frequency of observed apnea (p = 0.002). In multiple linear regression model 2, AHI was associated with higher BMI (p < 0.001) and loudness of snoring (p = 0.018). Conclusions The present preliminary results suggest that BMI and observed apnea are most influential factors that affect AHI in suspected OSA patients. In the future study we will design the prediction formula for the OSA and AHI, which is useful in the clinical medical field.