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Global Carbon Cycle and Budget Study (지구규모의 탄소 순환 및 물질수지 연구)

  • 권오열
    • Journal of Environmental Science International
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    • v.5 no.4
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    • pp.429-440
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    • 1996
  • A global carbon cycle model (GCCM), that incorporates interaction among the terrestrial biosphere, ocean, and atmosphere, was developed to study the carbon cycling aid global carbon budget, especially due to anthropogenic $CO_2$ emission. The model that is based on C, 13C and 14C mass balance, was calibrated with the observed $CO_2$ concentration, $\delta$13C and $\Delta$14C in the atmosphere, Δ14C in the soil, and $\Delta$14C in the ocean. Also, GCCM was constrained by the literature values of oceanic carbon uptake and CO, emissions from deforestation. Inputs (forcing functions in the model) were the C, 13C and 14C as $CO_2$ emissions from fossil fuel use, and 14C injection into the stratosphere by bomb-tests. The simulated annual carbon budget of 1980s due to anthropoRenic $CO_2$ shows that the global sources were 5.43 Gt-C/yr from fossil fuel use and 0.91 Gt-C/yr from deforestation, and the sinks were 3.29 Gt-C/yr in the atmosphere, 0.90 Gt-C/yr in the terrestrial biosphere and 2.15 Gt-C/yr in the ocean. The terrestrial biosphere is currently at zero net exchange with the atmosphere, but carbon is lost cia organic carbon runoff to the ocean. The model could be utilized for a variety of studies in $CO_2$ policy and management, climate modeling, $CO_2$ impacts, and crop models.

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Declining Fixed Investment and Increasing Financial Investment of Korean Corporations

  • Kim, Daehwan;Kwon, Sunhee;Ryou, Jai-Won
    • East Asian Economic Review
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    • v.23 no.4
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    • pp.353-379
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    • 2019
  • This paper aims to determine factors causing the stagnation of Korean firms' fixed investment after the global financial crisis, using panel data for the period of 1999-2016. Fixed investment remained sensitive to cash flow and Tobin's q although their effects decreased after the global financial crisis. A decreasing trend of cash flow and an increase in Tobin's q since the early 2000's imply that the worsening cash flow was a major factor behind the sluggish investment after the crisis. Meanwhile, debt-equity ratio remained significant for non-chaebol affiliated firms, reflecting disparity in access to external financing. Volatility of stock returns also became insignificant after the crisis, casting doubt on the argument that uncertainty was a major factor contributing to the decline of fixed investment. Analysis of financial investment confirmed the significant effect of cash flow, larger than that on financial investment than on fixed investment. In particular, debt repayment and other financial investment, except share repurchase, were sensitive to cash flow. However, the substitution of fixed investment by financial investment is a consequence, rather than a cause of declining fixed investment.

Table Structure Recognition in Images for Newspaper Reader Application for the Blind (시각 장애인용 신문 구독 프로그램을 위한 이미지에서 표 구조 인식)

  • Kim, Jee Woong;Yi, Kang;Kim, Kyung-Mi
    • Journal of Korea Multimedia Society
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    • v.19 no.11
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    • pp.1837-1851
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    • 2016
  • Newspaper reader mobile applications using text-to-speech (TTS) function enable blind people to read newspaper contents. But, tables cannot be easily read by the reader program because most of the tables are stored as images in the contents. Even though we try to use OCR (Optical character reader) programs to recognize letters from the table images, it cannot be simply applied to the table reading function because the table structure is unknown to the readers. Therefore, identification of exact location of each table cell that contains the text of the table is required beforehand. In this paper, we propose an efficient image processing algorithm to recognize all the cells in tables by identifying columns and rows in table images. From the cell location data provided by the table column and row identification algorithm, we can generate table structure information and table reading scenarios. Our experimental results with table images found commonly in newspapers show that our cell identification approach has 100% accuracy for simple black and white table images and about 99.7% accuracy for colored and complicated tables.

Global Distribution of Surface Layer Wind Speed for the years 2000-2009 Based on the NCEP Reanalysis (NCEP 재분석 자료를 이용한 전지구 지표층의 2000-2009년 풍속 분포)

  • Byon, Jae-Young;Choi, Young-Jean;Lee, Jae-Won
    • Atmosphere
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    • v.21 no.4
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    • pp.439-446
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    • 2011
  • NCEP reanalysis data were analyzed in order to provide distribution of global wind resource and wind speed in the surface layer for the years 2000-2009. Wind speed at 10 m above ground level (AGL) was converted to wind speed at 80 m above the ground level using the power law. The global average 80 m wind speed shows a maximum value of $13ms^{-1}$ at the storm track region. High wind speed over the land exists in Tibet, Mongolia, Central North America, South Africa, Australia, and Argentina. Wind speed over the ocean increased with a large value in the South China Sea, Southeast Asia, East Sea of the Korea. Sea surface wind in Western Europe and Scandinavia are suitable for wind farm with a value of $7-8ms^{-1}$. Areas with great potential for wind farm are also found in Eastern and Western coastal region of North America. Sea surface wind in Southern Hemisphere shows larger values in the high latitude of South America, South Africa and Australia. The distribution of low-resolution reanalysis data represents general potential areas for wind power and can be used to provide information for high-resolution wind resource mapping.

Improvement of the Stratospheric Wind Analysis with the Climatological Constraint in the Global Three-Dimensional Variational Assimilation at Korea Meteorological Administration (3차원 변분법의 제한조건 적용을 통한 기상청 전지구 모델의 성층권 바람장 개선)

  • Joo, Sangwon;Lee, Woo-Jin
    • Atmosphere
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    • v.17 no.1
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    • pp.1-15
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    • 2007
  • A constraint based on climatology is introduced to the cost function of the three-dimensional variational assimilation (3dVar) to correct the error of the zonal mean wind structure in the global data assimilation system at Korea Meteorological Administration (KMA). The revised cost function compels the analysis fit to the chosen climatology while keeping the balance between the variables in the course of analysis. The constraint varies selectively with the vertical level and the horizontal scale of the motion. The zonally averaged wind field from European Centre for Medium-Range Weather Forecasts Re-Analysis 40 (ERA-40) is used as a climatology field in the constraint. The constraint controls only the zonally averaged stratospheric long waves with total wave number less than 20 to fix the error of the large scale wind field in the stratosphere. The constrained 3dVar successfully suppresses the erroneous westerly in the stratospheric analysis promptly, and has been applied on the operational global 3dVar system at KMA.

Comparison of Global Field Power Measurement and Conventional Method in Multi-channel Auditory Event Related Potential P300 Determination (다채널 청각 사건관련전위 P300 결정에서 전부위장력측정법과 전통적방법의 비교)

  • Jeon, Yang-Whan;Han, Sang-Ick
    • Korean Journal of Biological Psychiatry
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    • v.7 no.2
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    • pp.180-185
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    • 2000
  • Objective : The present study was designed to compare Global Field Power Measurement and conventional method in P300 determination. Method : The subjects were composed of patients(N=20) with schizophrenia by DSM-IV and normal controls(N=20). The auditory event related potential P300 was measured by "oddball paradigm". P300 components were determined by Global Field Power Measurement and conventional method at 5 electrodes(Fz, Cz, Pz, $T_3$, $T_4$). Results : P300 amplitudes of patients were smaller than those of controls across all electrodes and in both methods, but there was no differential power in P300 determination between two methods. Asymmetry of auditory event-related potential P300 was not shown between patients with schizophrenia and normal controls. Conclusion : It is implicated that it depends on clinical situations and research purposes what method of P300 determination will be more appropriate for patients with schizophernia.

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Declining Japanese Yen in the Changing International Monetary System

  • Ogaw, Eiji;Muto, Makoto
    • East Asian Economic Review
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    • v.21 no.4
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    • pp.317-342
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    • 2017
  • The US dollar has kept as a position of key currency in the global economy in the changing international monetary system where the euro was introduced to some states of the EU in 1999. It is an evidence of inertia of the US dollar as a key currency. Our previous study (Ogawa and Muto, 2017b) conducted empirical analysis to investigate effects of several events on inertia of the US dollar. One of our findings was that the introduction of the euro increased utility of euro while utility of US dollar was kept unchanged. This paper examines the effects of the global financial crisis and the euro zone crisis as well as the introduction of the euro on the utility of the Japanese yen. The introduction of the euro significantly decreased the utility of the Japanese yen. It indicates that the introduction of the euro increased the utility of the euro while reducing the utility of the Japanese yen rather than the utility of the US dollar. The utility of the Japanese yen has significantly decreased while the global financial crisis and the euro zone crisis occurred. The Japanese yen has a declining trend in terms of its utility over time in the changing international monetary system.

Global Value Chain in East Asia Under "New Normal": Ideology- Technology-Institution Nexus

  • Choi, Byung-il
    • East Asian Economic Review
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    • v.24 no.1
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    • pp.3-30
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    • 2020
  • This paper analyzes how the current Global Value Chain (GVC) of East Asia has been established, and attempts to project the future trajectory of GVC under New Normal in the global trading system. For this purpose, the framework of Ideology-Technology-Institution nexus is presented with focus on the dynamics of interplay between ideology and technology, duly recognizing the dual-aspect of technology- a platform for business and also for national defense. The paper analyzes how the Information and Communication Technology (ICT) of the 1990s played a role of "facilitator" in shaping the GVC of East Asia, where China plays 'factory for final assembly' and the US plays 'the largest consumer'. Under New Normal, digital technology is likely to play the opposite role of "disrupting" the GVC of East Asia, unlike ICT. The paper explores the mechanism behind this great disruption. What is driving New Normal is the US-China power competition, seeking for dominance in East Asia and beyond. This paper argues that New Normal is not temporary shock, but will last for some time. Under this presumption, the paper presents three scenarios for the future trajectory of GVC in East Asia.

A Study on the Optimization Method using the Genetic Algorithm with Sensitivity Analysis (민감도가 고려된 알고리듬을 이용한 최적화 방법에 관한 연구)

  • Lee, Jae-Gwan;Sin, Hyo-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.6 s.177
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    • pp.1529-1539
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    • 2000
  • A newly developed optimization method which uses the genetic algorithm combined with the sensitivity analysis is presented in this paper. The genetic algorithm is a probabilistic method, searching the optimum at several points simultaneously, requiring only the values of the object and constraint functions. It has therefore more chances to find global solution and can be applied various problems. Nevertheless, it has such shortcomings that even it approaches the optimum rapidly in the early stage, it slows down afterward and it can't consider the constraints explicitly. It is only because it can't search the local area near the current points. The traditional method, on the other hand, using sensitivity analysis is of great advantage in searching the near optimum. Thus the combination of the two techniques makes use of the individual advantages, that is, the superiority both in global searching by the genetic algorithm and in local searching by the sensitivity analysis. Application of the method to the several test functions verifies that the method suggested is very efficient and powerful to find the global solutions, and that the constraints can be considered properly.

Characterization of a Chromosomal Nickel Resistance Determinant from Klebsiella oxytoca CCUG 15788

  • Park, Jae-Sun;Lee, Sung-Jae;Rhie, Ho-Gun;Lee, Ho-Sa
    • Journal of Microbiology and Biotechnology
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    • v.18 no.6
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    • pp.1040-1043
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    • 2008
  • Klebsiella oxytoca CCUG 15788 is resistant to $Ni^{2+}$ at a concentration of 10 mM and grows in an inducible manner when exposed to lower concentrations of $Ni^{2+}$. The complete genomic sequence of a 4.2-kb HindIII-digested fragment of this strain was determined from genomic DNA. It was shown to contain four nickel resistance genes (nirA, nirB, nirC, and nirD) encoding transporter and transmembrane proteins for nickel resistance. When the plasmid pKOHI4, encoding nirABCD, was transformed into Escherichia coli JM109, the cells were able to grow in Tris-buffered mineral medium containing 3 mM nickel. TnphoA'-1 insertion mutants in the four nickel genes nirA, nirB, nirC, and nirD showed nickel sensitivity. The nir genes were heterogeneously expressed in E. coli, suggesting functional roles of these genes in nickel resistance.