• Journal of the Korean Geographical Society
• /
• v.51 no.5
• /
• pp.667-690
• /
• 2016

This paper reviews the evolution process of global production network(GPN) discourse, from its origin to the recent theorization, namely GPN 2.0. In so doing, the discursive formation of global production networks is introduced in comparison with a competing discourse global commodity/value chains, with particular attention to conceptual and analytical lacunae in the latter. This article also outlines how the global production network perspective has become a useful discursive and practical tool that allows the examination of the nexus of global economy, transnational corporations, and regional development. Subsequently, a theoretical dearth in the approach is discussed in reference to key critiques, and in this context Yeung and Coe's recent theorization GPN 2.0, which is centered on casual mechanisms and network configurations is reviewed. This paper suggests that the theory adequately addresses the problem of casuality lacking in its precedented conceptual framework, and that it helps exploring the formation and evolution processes of varied production networks(including intrafirm coordination, interfirm control, strategic partnership, and extrafirm bargaining) in connection with competitive dynamics and risky environments. As a result of the theorization, the difference between GPN and the chain approaches has become more apparent, and the idea of extrafirm bargaining is particularly important in the differentiation. Extrafirm bargaining is seen to be a comprehensive networking form inclusive of such GPN 1.0 analytical concepts as value, embeddeness, and power, and research attentive to, and engaging with, the extrafirm networks is expected to help transcending the chain governance approaches' analytical excess of interfirm linkages and industry-centeredness.

• Nuclear Engineering and Technology
• /
• v.47 no.6
• /
• pp.678-699
• /
• 2015

Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.

• Journal of Korean Philosophical Society
• /
• v.147
• /
• pp.179-214
• /
• 2018

In this paper I understand Zizek's interpretation of Christianity, and examine it critically and suggest its alternative. Zizek argues that Christianity in its core is turned out to be atheist. His atheist Christianity exposes revolutionary potentials with Christianity. His exploration of Christianity is designed to fight against global capitalism. It means an ideological praxis in theory. But he is misleading in interpreting Christianity. It is his fault that while he places much stress on the participatory interpretation of Jesus's death, he belittles the sacrificial interpretation of it. For the subversive power of Christianity springs from the latter. To tell the truth, Christianity is strongly grounded on simultaneous fulfillment of both of them. Zizek. In interpreting Christianity, he delivers us uncorrect understanding of sacrificial interpretation of Jesus's death while he intends to reveal the subversive core of Christianity. In particular, he is lacking in understanding the atonement function and expiation effect immanent in Jesus's death. There is no participatory interpretation without sacrificial interpretation. In this view, Zizek's pagan Christianity has to be revised or rejected. So, I suggest it is possible through orthodox Christianity, not through pagan Christianity to restore and reactivate the subversive core of Christianity in itself and by itself. The burden of proof is up to fighting theist, not fighting atheist like Zizek.

• Journal of the Korean Institute of Gas
• /
• v.22 no.6
• /
• pp.65-75
• /
• 2018

The wind energy produced at night is being discarded because of the excess power generated at night compared to daytime. To solve this problem, In this study, we analyzed the evaluation contents for evaluation of domestic and overseas water electrolysis systems and drew contents for safety performance contents test of the water electrolysis system based on the evaluation contents. The test contents produced the efficiency measurement test, the hydrogen generated pressure test, and the hydrogen purity test. And the safety performance evaluation of the alkaline water electrolysis system of $5Nm^3/hr$ was performed based on the results. As a result, the hydrogen generation was calculated as $5.10Nm^3/hr$ and the stack efficiency was $4.97kWh/Nm^3$. The purity of the hydrogen generated was 99.993% and it was confirmed that it produced high purity hydrogen. I think will help us assess and build safety performance of water electrolysis systems in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.6
• /
• pp.553-560
• /
• 2020

This paper presents an algorithm for identifying and eliminating errors by seagrasses in coastal bathymetry surveying using drone and HD camera. Survey errors due to seagrasses were identified, segmentated and eliminated using a L∗a∗b color space model. Bathymetry survey using a drone and HD camera has many advantages over conventional survey methods such as ship-board acoustic sounder or manual level survey which are time consuming and expensive. However, errors caused by sea bed reflectance due to seagrasses habitat hamper the development of new surveying tool. Seagrasses are the flowering plants which start to grow in November and flourish to maximum density until April in Korea. We developed a new algorithm for identifying seagrasses habitat locations and eliminating errors due to seagrasses to get the accurate depth survey data. We tested our algorithm at Wolpo beach. Bathymetry survey data which were obtained using a drone with HD camera and calibrated to eliminate errors due to seagrasses, were compared with depth survey data obtained using ship-board multi-beam acoustic sounder. The abnormal bathymetry data which are defined as the excess of 1.5 times of a standard deviation of random errors, are composed of 8.6% of the test site of area of 200 m by 300 m. By applying the developed algorithm, 92% of abnnormal bathymetry data were successfully eliminated and 33% of RMS errors were reduced.

• KDI Journal of Economic Policy
• /
• v.14 no.1
• /
• pp.3-36
• /
• 1992

"Corporate control by owners" characterizes the current structure of ownership, control and management of big business groups in Korea. It has become an ever more serious obstacle for the Korean economy to end its distinctive "personal capitalism" and to transform the current system into people's capitalism. The current issue, the deconcentration of ownership, through the course of heated debates should be treated from an integrated perspective. That is, the debate should center on the concentration of economic power and it effects on national economy, instead of sticking to the issue of ownership-control issue per se. This paper, by referring to the historical experiences and development paths which advanced countries have already traveled, analyzes the respective aspects of the concentration issue in a rather descriptive and taxonomist manner - market concentration, business diversification, ownership concentration, integrated management of conglomerates, i.e., managing in groups' unit, and the roles of financial institutions. The government policies against the concentration of economic power have so far focused on the size of big business groups and their diversification activities. The two major policy measures are restrictions on cross-ownership and excess capital investment by big business groups, and controls on their credit deals. This paper strongly suggests that the government should change its current priorities in targeting its policies against concentration. The government should reduce the regulations on size and diversification, and focus its policies on substantial dispersion of corporate ownership. The efficacy of government intervention in the management and control of business enterprises seems quite dubious and even anachronistic given the extent of maturity of Korean firms. Therefore, it should be noted that the current regulation-oriented stance taken by the government against the management style of big business groups should be suppressed, as it has assumed some a priori and typical pattern in advance in directing big business groups, such as independent and specialized management in respective firms' unit. This paper, also, raises the need for introducing new regulations on inter-sectoral diversifications between finance, industry and the press.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.1
• /
• pp.71-81
• /
• 2005

The purposes of this study was to collect, analyze, and describe the MF exposure levels from subways in Korea and to measure and evaluate the MF levels generated from electric appliances used at general homes. The target subway lines were Seoul Metropolitan Line 1 to Line 8, Bundang Line, Incheon Line, Daegu Line, Gwangju Line, and Busan Line 1 and Line 2. We measured at each station in those subway lines and, all the train types (pantograph-equipped, motor-equipped, and common), and platform types(facing and isolating) were investigated by the distance(80, 200, 400 cm) from the train on 19 targeted subway lines using 3 magnetic field measuring devices (EMDEXII, Enertech Co.) during the survey from January till October, 2004. On the other hand, the levels of the 60Hz magnetic fields generated from 14 items of home electric appliances such as electric blankets, hair dryers, electric razors, etc. were measured at 10 general homes using 5 EMDEXII meters with a sampling interval of 1.5 second by the distance(surface, 30, 50, 100, 300cm ) from the target electric appliances. The survey results in the whole subway lines examined in this study were as follows; Seoul Metropolitan Line 4 using AC(alternating current) power source showed the highest mean value of $2.85{\mu}T$, followed by Seoul Metropolitan Line 1 running between Seoul and Incheon using AC($2.78{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Uijongbu using AC($2.73{\mu}T$), Bundang Line using AC($1.79{\mu}T$), Seoul Metropolitan Line 1 connected from Yongsan using AC($1.67{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Suwon using AC($0.79{\mu}T$), and so on. In general, the intensity of the magnetic field in the subway systems in Korea was significantly higher when using AC($2.14{\pm}0.91{\mu}T$) than when using DC($0.29{\pm}0.44{\mu}T$) power source. Among the home electric appliances examined, microwave ovens showed the highest mean value of $7.69{\mu}T$, followed by hair dryers($6.47{\mu}T$), vacuum cleaners($5.27{\mu}T$), televisions ($2.26{\mu}T$), electric blankets($1.38{\mu}T$), personal computers ($0.81{\mu}T$), and so on. Two items of electric appliances showed the excess value of $0.2{\mu}T$ at the distance of 30cm in the MF exposure level; electric razors $1.58{\pm}2.13{\mu}T$ and vacuum cleaners $0.48{\pm}0.44{\mu}T$. As a whole, this study showed a tendency that the shift of the MF levels according to the increase of distance from the electric appliances was lower than those of the results surveyed in UK and USA. As a result, this study is expected to suggest meaningful data for the future study in exposure assessment of magnetic fields and for the establishment of guidelines for subways and electric appliances in Korea. More detailed and large scaled exposure assessment studies should be performed continuously to get the various and useful information on health risk assessment of MFs in Korea.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.36 no.4
• /
• pp.318-324
• /
• 2016

In order to study the effect of barley, Italian ryegrass (IRG), and legume mixture on nitrogen fixation and transfer to grasses on spring paddy field, an experiment was carried out from Oct. 2006 to June 2007 in Naju, Korea. A split plot design with three replications was used for the experiment. One reference plot was assigned for each treatment to determine nitrogen fixation. Main plots consisted of Chinese milk vetch, crimson clover, forage pea, and hairy vetch with barley, respectively. Subplot treatment were barley or IRG with four seeding ratio of legumes (50:50, 60:40, 70:30, and 80:20). To estimate N fixation by legumes, $^{15}N$ isotope dilution technique was used. $^{15}N$ fertilizer [$(^{15}NH_4)_2SO_4$ solution at 99.8 atom N] was uniformly applied to $600cm^2$ in the middle of each plot on April 15, 2007. Plots were harvest by hand on June 8, 2007. Dried sample were ground to a fine power and analyzed for total N isotope N. $^{15}N$ was determined using elemental analyzer-isotope ratio mass spectrometry. The calculation of N transfer was determined with the isotope dilution method. The content of N was higher in legumes than that in barley or Italian ryegrass. Nitrogen level in forage pea was significantly higher than that of other legumes. There were significantly differences in N content between legumes in IRG mixture. Atom % $^{15}N$ excess was significantly different in legumes with barley. The 60:40 sub plot had higher (p<0.05) atom % $^{15}N$ than other seeding ratio treatments. The enrichment ranged from 0 to 0.58. Compared to barley, the enrichment of IRG with its accompanied legumes was higher, ranging from 0.38 to 1.0. The N derived from the atmosphere (Ndfa) ranged from 0% to 49.5% with barley-legume mixture. It ranged from 0 to 60.5% in IRG-legume plots. N transfer from legumes to neighboring grasses was 12.3 to 90.9 kg/ha for barley-legume mixture and 31.7 to 107.8 kg/ha for IRG plots. IRG plots showed higher N transfer for IRG-legume mixture in general based on difference method. Based on $^{15}N$ dilution method, the N transfer was 0 to 36.1 kg/ha for barley-legume mixture and 0 to 50.6 kg/ha for IRG plots. There was a tendency toward higher N transfer on the difference method than that of the $^{15}N$ dilution method.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.12 no.1
• /
• pp.7-11
• /
• 1983

The purpose of this study was to prepare low methoxyl pectins (LMPs) by pectinesterase (PE) using waste tangerine peels and to compare the chemical, physical and gelling properties of the prepared pectins with the commercial LMP. The LMPs were prepared by treating albedo with 0.25M $Na_2CO_3$ to activate the PE. PE was then inactivated by heating. The sample was centrifuged and the supernatant was collected. LMP was obtained as precipitate by adding alcohol to the collected supernatant. The amounts of extractible pectins in albedo were 12.71~12.98% on a dry weight basis. Methoxyl contents of LMPs prepared by treating albedo with PE at pH 7.5 for 10min, at pH 8.5 for 10min, 20min and 30min were 5.12%, 4.27%, 3.08%, 1.85% respectively, demonstrating that the methoxyl contents of the preparations decreased as the degree of treatment albedo with PE increased. The acetyl contents of the preparations ranged from 0.09% to 0.12%, the values of which do not interfere with gel formation. The anhydrouronic acid contents of the prepared pectins were in the range of 94.2%~94.8%. The values of viscosity and molecular weights of the prepared LMPs tent to decrease as the degree of PE action on albedo increased. The textural value of the prepared LMP gels determined by Consistometer, Ridgelimeter and Instron denonstrated that the excess treatment of albedo with PE significantly impaired the gelling properties of the preparations.