• 제목/요약/키워드: Backward dispersion

검색결과 33건 처리시간 0.03초

산업연관분석에 의한 운송부문별 국민경제적 파급효과의 상호비교 분석 (A Comparative Study on Economic Effects on the Korean Economy by Transport Mode Using Input-Output Analysis)

  • 이태우;장영태;신성호
    • 한국항만경제학회:학술대회논문집
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    • 한국항만경제학회 2006년도 국제학술대회
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    • pp.103-124
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    • 2006
  • This paper is concerned with a comparative study on the economic effects upon the Korean economy by transport mode, ie road, rail, air, and coastal and inland water transportation between 1990 and 2000, using input-output analysis. The economic effects consist of backward and forward linkage effects, production inducing and import-inducing effects. The data employed for this study come from the Bank of Korea database for Input-Output structure of the Korean economy. The major findings in this study are, among others:(1) the power of dispersion(=backward linkage effect) of coastal and inland water transportation sector is the highest among the four transport sectors, while road cargo transport mode showed the highest the degree of sensitivity (=forward linkage effect); (2) rail cargo transport recorded the highest production inducing effects; and (3) air transport mode achieved the highest ranking in the import-inducing effects.

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복합지형상에서 비정상 박리흐름에 의한 확산 (Dispersion in the Unsteady Separated Flow Past Complex Geometries)

  • 류찬수
    • 한국지구과학회지
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    • 제22권6호
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    • pp.512-527
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    • 2001
  • 복합지형을 지나는 박리흐름(separated flows)들이 와도 이론에 의해 모델링 되었다. 흐름은 비회전성 및 비점성으로 가정하였으며, 선형 시어흐름에 대한 유선함수를 결정하기 위해 새로운 기법이 기술되었다. 지형지물의 형태로는 snow cornice과 backward-facing step을 정의하였으며, 이러한 지형지물의 후미에는 유체의 박리현상과 역류현상(reattachment)이 생긴다. 유체의 박리현상이 지형지물의 가장자리에 발생되게 하기 위해 점 와도를 흐름에 발생시켰고, 지형지물의 가장자리에 있는 뾰족한 부분을 완화하고 최대곡률 부근에서의 섭동운동에 중요한 박리흐름 발생지점의 구속조건을 없애기 위해 conformal mapping을 수정하였다. 와도 발생지점에서 와도를 평형으로부터 이동시키거나, 또는 임의의 섭동을 초기흐름에 가하는 방식으로 섭동을 가하여 비정상흐름을 발생시켰다. 박리지점의 풍상측에서 연속적으로 방출되고, 또한 bubble의 이차순환에 의해 변형된 물질의 궤적들이 수치적으로 적분되었으며, 시간에 대한 농도누적이 역류지점의 풍하측 고정된 지점에서 계산되었다. 본 연구에 사용된 모델은 방출물질의 확산형태와 간헐성을 제대로 다룰 수 있음을 알 수 있으며, 이산적인 방법에 의한 다중-와도모델 및 수치모델의 결과들과도 일치한다. 본 연구에 의하면, 박리 및 역류현상이 있는 유체의 흐름 속에 순환하는 bubble들의 비정상상태(unsteadiness)는 풍하측에서 대규모의 고농도 누적을 일으키는 주요 원인이다.

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지식정보사회의 신경제공간과 지리학 연구의 방향 (New Economic Spaces and Directions of Geographical Research in the Knowledge-Based Information Society)

  • 박삼옥
    • 대한지리학회지
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    • 제41권6호
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    • pp.639-656
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    • 2006
  • 본 연구는 지식정보사회에서 신경제공간 형성의 메커니즘을 살펴보고 향후 지리학연구의 방향을 제시하고자 하였다. 정보화 사회에서 신경제공간의 형성 배경에 대해 개관하고, 그 메커니즘으로 네트워크, 착근성, 집적 및 분산에 대해서 설명하였다. 또한 한국에서 혁신활동이 활발한 서울의 강남지역과 낙후지역 중의 하나인 전북 순창지역에 대한 사례연구를 통하여 한국의 낙후지역에서도 신경제공간의 형성이 이루어지고 있음을 지적하였다. 이러한 이론적 논의와 사례연구를 바탕으로 앞으로 지리학연구의 방향을 크게 통합적 관점에서의 연구, 지리학연구 방법론 개발, 정책관련연구의 세 가지 측면에서 논의하였다.

산업연관표를 이용한 국내 외국인직접투자의 경제적 파급효과 분석 (A Study on the Economic Impact of Focused on the Input-output Table in the FDI inflow)

  • 지영한
    • 통상정보연구
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    • 제18권1호
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    • pp.235-258
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    • 2016
  • 본 연구는 산업연관표를 중심으로 2011년~2013년 기간의 실측표기준의 투입산출물표(Input-output Table)를 사용하여 동 기간의 국내 해외직접투자(FDI) 유입액을 한국표준산업분류(KSIC 30부문)기준으로 재분류 및 통합하여 적용한 결과 3개년 평균 국내 외국인직접투자 유입액은 15조 3,000억원이고, 평균총생산유발액은 45조 8,000억원으로 추계되었다. 국내 외국인직접투자 유입의 특징은 감응도계수 및 영향력계수가 큰 산업인 화학제품, 전기 및 전자기기, 금속제품에 편중되어 있다. 특히 중간재로 활용되는 감응도계수가 큰 산업에 국내 외국인직접투자 유치가 이루어지면 국내 경제적 산업파급효과가 큰 것으로 나타난다.

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농업생산기반 정비사업의 산업연관효과분석 -황락 저수지지구를 중심으로- (Analysis of Industrial Linkage Effects for Farm Land Base Development Project -With respect to the Hwangrak Benefited Area with Reservoir -)

  • 임재환;한석호
    • 농업과학연구
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    • 제26권2호
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    • pp.77-93
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    • 1999
  • This study is aiming at identifying the foreward and backward lingkage effects of the farm land base development project. Korean Government has continuously carried out farmland base development projets including the integrated agricultural development projects. large and medium scale irrigation projects and the comprehensive development of the four big river basin including tidal land reclamation and estuary dam construction for the all weather farming since 1962. the starting year of the five year economic development plans. Consequently the irrigation rate of paddy fields in Korea reached to 75% in 1998 and to escalate the irrigation rate, the Government had procured heavy investment fund from IBRD. IMF and OECF etc. To cope with the agricultural problems like trade liberalization in accordance with WTO policy, the government has tried to solve such problems as new farmland base development policy, preservation of the farmland and expansion of farmland to meet self-sufficiency of foods in the future. Especially, farmland base development projects have been challanged to environmental and ecological problems in evaluating economic benefits and costs where the value of non-market goods have not been included in those. Up to data, in evaluating benefits and costs of the projects, farmland base development projects have been confined to direct incremental value of farm products and it's related costs. Therefore the projects'efficiency as a decision making criteria has shown the low level of economic efficiencies. In estimating economic efficiencies including Leontiefs input-output analysis of the projects could not be founded in Korea at present. Accordingly this study is aimed at achieving and identifying the following objectives. (1) To identify the problems related to the financial supports of the Government in implementing the proposed projects. (2) To estimated backward and foreward linkage effects of the proposed project from the view point of national economy as a whole. To achieve the objectives, Hwangrak benefited area with reservoir which is located in Seosan-haemi Disticts, Chungnam Province were selected as a case study. The main results of the study are summarized as follows : a. The present value of investment and O & M cost were amounted to 3,510million won and the present value of the value added in related industries was estimated at 5.913million won for the period of economic life of 70 years. b. The total discounted value of farm products in the concerned industries derived by the project was estimated at 10,495million won and the foreward and backward linkage effects of the project were amounted to 6,760 and 5,126million won respectively. c. The total number of employment opportunities derived from the related industries for the period of project life were 3,136 man/year. d. Farmland base development projects were showed that the backward linkage effects estimated by index of the sensitivity dispersion were larger than the forward linkage effect estimated by index of the power of dispersion. On the other hand, the forward linkage effect of rice production value during project life was larger than the backward linkage effect e. The rate of creation of new job opportunity by means of implementing civil engineering works were shown high in itself rather than any other fields. and the linkage effects of production of the project investment were mainly derived from the metal and non-metal fields. f. According to the industrial linkage effect analysis, farmland base development projects were identified economically feasible from the view point of national economy as a whole even though the economic efficiencies of the project was outstandingly decreased owing to delaying construction period and increasing project costs.

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후방복사 리키 램파를 이용한 위상속도 분산곡선과 군속도의 측정 (Determination of phase velocity dispersion curve and group velocity using backward radiated leaky Lamb waves)

  • 김영환;송성진;천권수;권성덕
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2002년도 하계학술발표대회 논문집 제21권 1호
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    • pp.529-534
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    • 2002
  • 유도초음파는 얇은 판재와 다층재료를 평가하는데 널리 사용되는데, 이를 정량적으로 이용하기 위해서는 위상 및 군속도의 분산선도는 필수적이다. 본 연구에서는 후방복사 리키 램파를 이용하여 위상속도 분산곡선과 군속도를 측정하였다. 물에 잠긴 판재에 입사각을 변화 시키면서 판재에서 발생하는 후방복사 초음파 신호를 측정하였고, 후방복사된 초음파 신호는 유도초음파의 분산특성을 지님을 보였다. 입사각도와 수신된 파형의 주파수 분석을 통하여 램파의 위상속도 분산선도를 구하였다. 또한, 특정한 입사각에서 입사점을 변화시키면 서 론 파형의 시간대역 이동으로부터 군속도를 측정하였다.

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Subwavelength 결함접지구조(defected grounded structure : DGS)를 이용한 Homogeneous Dual Composite Right/Left-Handed 메타물질 구현 (Homogeneous Dual Composite Right/Left-Handed Metamaterial Using Subwavelength Defected Ground Structure(DGS))

  • 박우영;임성준
    • 전기학회논문지
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    • 제58권11호
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    • pp.2242-2246
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    • 2009
  • In this paper, a homogeneous dual composite right/left-handed (D-CRLH) transmission line (TL) is proposed by using a defected ground structure (DGS) on the ground plane. In order to satisfy a homogeneity condition of metamaterial, a subwavelength unit cell is designed by way of a spiral DGS and a meander stub. From a dispersion diagram, it is expected that the frequency bands for the left-handed (LH) property is 3.5 - 4.4 GHz. At 3.8 GHz in the LH band, backward propagating phenomenon is observed from full-wave analysis. The experimental results show that the proposed TL has a stop-band in 1.75 - 3.6 GHz.

주기적 정성적분석을 통한 훈련목표 제공이 남자 역도 인상기술 향상에 미치는 영향 (The Effect of snatch technique improvement for men weightlifter of feedback support through quantity analysis by periods)

  • 문영진;류중현;이순호
    • 한국운동역학회지
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    • 제14권2호
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    • pp.69-83
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    • 2004
  • The purpose of this study is searching for technical merits and demerits of each weight lifting player through qualitative motion analysis system. Moreover, It is also analysis the repeating the establishment of exercise purpose and studying for the effect of the field adaptation. The subject of this study was five male weight lifting players who have been engaged in Korean Delegation Team. The institution of exercise target was made through two times qualitative analysis and the result of studying for the effect of the field adaptation was produced before offering feedback. Moreover, two time analysis added after offering feedback. All analysis was based on 2-D visual analysis. The results of this study are as follows: 1. Maximal barbell moving speed in starting phase was decreased after offering feedback. This result implies advancement of technical skills after offering feedback. 2. From starting posture to 앉아받기, forward and backward moving distance of hip joint was decreased after offering feedback in all subjects. This result represents advancement of technical skills after offering feedback. 3. In terms of pull phase, forward and backward moving distance of hip and shoulder joint was decreased after offering feedback in all subjects. This result represents advancement of technical skills after offering feedback. 4. In terms of pull phase, the difference of horizontal value of coordinates was decreased after offering feedback in all subjects. This result represents advancement of technical skills after offering feedback. 5. In terms of pull phase, the motion range of hip joint was decreased after offering feedback in three of five subjects and this represents advancement of technical skills after offering feedback. However, the rest of them were not variable or narrow decreasing. This result represents that feedback system could not brought tremendous effects. 6. From apex point of barbell to 앉아받기, the difference of barbell height was decreased after offering feedback in three of five subjects and this represents advancement of technical skills after offering feedback. However, the rest of them weren't variable or narrow increasing. This result represents that feedback system could not brought tremendous effects. 7. In terms of last-pull phase, the angular velocity of knee joint was increased after offering feedback in four of five subjects and this represents advancement of technical skills after offering feedback. However, the rest of them, only one subject, decreased. This result represents that feedback system could not brought tremendous effects. 8. In terms of last-pull, the conversional tendency of maximal extension to flextion came out all but simultaneously without offering feedback in four of five subjects. This is well-performed technique. Only one subject, however, could not use power effectively because the fact that his maximal extension came out in serial, from ankle to knee and waist means dispersion of power. In addition to, after offering feedback, only one subject made increasing the maximal extension of knee in last-pull and this result represents advancement of skills after offering feedback. However, the rest of them could not make meaningful development after offering feedback. 9. It might be assumed that searching for technical merits and demerits of each weight lifting player through qualitative motion analysis system could improve player's skill.

An Orchestrated Attempt to Determine the Chemical Properties of Asian Dust Particles by PIXE and XRF Techniques

  • Ma, Chang-Jin;Kim, Ki-Hyun;Choi, Sung-Boo;Kasahara, Mikio;Tohno, Susumu
    • Asian Journal of Atmospheric Environment
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    • 제4권3호
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    • pp.189-197
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    • 2010
  • An orchestrated attempt was made to analyze samples of bulk and individual particulate matters (PM) collected at the Gosan ground-based station on the west coast of Jeju, Korea. A two-stage filter pack sampler was operated to collect particles in both large (> $1.2\;{\mu}m$) and small size fractions (< $1.2\;{\mu}m$) between the Asian dust (hereafter called "AD") storm event and non-Asian dust period. Elemental components in bulk and individual particles were determined by PIXE and synchrotron XRF analysis systems, respectively. To assess the transport pathways of air parcels and to determine the spatial distribution of PM, the backward trajectories of the Meteorological Data Explorer (Center for Global Environmental Research, 2010) and the NOAA's HYSPLIT dispersion-trajectory models were applied. In line with general expectations, Si and other crustal elements in large size particles showed considerably higher mass loading on AD days in comparison with non-AD days. Computation of the crustal enrichment factors [(Z/Si)$_{particle}$/(Z/Si)$_{desert}$ sand] of elements in large size particles (> $1.2\;{\mu}m$) allowed us to estimate the source profile and chemical aging of AD particles as well as to classify the soil-origin elements. On the basis of a single particle analysis, individual AD particles are classified into three distinct groups (neutralized mineral particles, S-rich mineral particles, and imperfectly neutralized particles).

희토류가 수소화 촉매에 미치는 영향 (Effect of Rare Earth Metal on Catalyst for Hydrogenation Reaction)

  • 안재용;전종기
    • 한국응용과학기술학회지
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    • 제35권1호
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    • pp.151-156
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    • 2018
  • 산업과 의학이 발전되면서 많은 인구는 삶의 질에 관심을 가지게 되었다. 건강에 대한 시각이 높아지면서 육류보다 채식 또는 식물성 오일을 선호하게 되었다. 오늘날 주로 니켈 촉매를 사용한 공정이 개발되면서 식물성 오일의 보존기간이 늘어나고 이동성이 편리해졌다. 현재 유지경화용 니켈 촉매는 외국기업이 세계시장을 장악하고 있다. 한편, 국내 니켈 촉매의 대량 생산 기술은 퇴보 되어 전량 외국에서 수입하고 있는 실정이다. 따라서 활발한 기초연구가 필요하고 국내에서 상용화 할 수 있는 촉매개발이 필요하다. 본 연구는 수소화 반응으로부터 유지경화에 기반이 되는 니켈을 주 활성 촉매제로 사용하였고, 희토류가 촉매의 활성에 주는 영향을 알아보았다. 일정량의 희토류는 니켈의 분산을 유도하여 효율을 증가시키고 조촉매로써 사용이 가능하였다.