• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.297-298
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• 2005

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.5
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• pp.699-705
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• 2011

A combined heat and power cogeneration system driven by low-temperature sources is investigated by the first and second laws of thermodynamics. The system consists of Organic Rankine Cycle (ORC) and an additional process heater as a series circuit. Seven working fluids of R152a, propane, isobutane, butane, R11, R123, isopentane and n-pentane are considered in this work. Maximum mass flow rate of a working fluid relative to that of the source fluid is considered to extract maximum power from the source. Results indicate that the second-law efficiency can be significantly increased due to the combined heat and power generation. Furthermore, higher source temperature and lower turbine inlet pressure lead to lower second-law efficiency of ORC system but higher that of combined system. Results also show that the optimum working fluid varies with the source temperature.

• Korea-Australia Rheology Journal
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• v.20 no.2
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• pp.59-63
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• 2008

A theoretical model was developed to describe the flow behavior of a filled polymer in the packing stage of reaction injection molding and predict the residual stress distribution of thin injection-molded parts. The model predictions were compared with experiments performed for phenol-formaldehyde resin filled with wood dust and cured by urotropine. The packing stage of reaction injection molding process presents a typical example of complex non-isothermal flow combined with chemical reaction. It is shown that the time evolution of pressure distribution along the mold cavity that determines the residual stress in the final product can be described by a single 1D partial differential equation (PDE) if the rheological behavior of reacting liquid is simplistically described by the power-law approach with some approximations made for describing cure reaction and non-isothermality. In the formulation, the dimensionless time variable is defined in such a way that it includes all necessary information on the cure reaction history. Employing the routine separation of variables made possible to obtain the analytical solution for the nonlinear PDE under specific initial condition. It is shown that direct numerical solution of the PDE exactly coincides with the analytical solution. With the use of the power-law approximation that describes highly shear thinning behavior, the theoretical calculations significantly deviate from the experimental data. Bearing in mind that in the packing stage the flow is extremely slow, we employed in our theory the Newtonian law for flow of reacting liquid and described well enough the experimental data on evolution of pressure.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.49-58
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• 2014

The illegal fishery act committed Chinese fishing vessels have not been stopped and Korea Coast Guard(KCG) has been injured or killed by chinese fishing forces, even though the Korean Government has been trying to control the illegal fishery and repeated violent act committed by Chinese fishing vessels in our Exclusive Economic Zone. Moreover, some problems in relation to the control process of KCG to suppress the illegal foreign fishing vessels has been exposed in spite of extensive efforts of Korean Government. Improper law enforcement of KCG in relation to foreign fishing vessels would cause international dispute between related states, although the control process to the illegal fishing vessels at sea is in a way of due law enforcement process forming a State's power. To this end, this paper examines the problems raised during the control process which is including the visit and inspection of illegal Chinese fishing vessels and law enforcement process exercised by KCG and presents practical solutions through analyzing the related materials, professional's opinion and recent cases.

• Journal of Korea Water Resources Association
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• v.51 no.3
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• pp.235-246
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• 2018

The main purpose of this study is to suggest a methodology for identifying vulnerable region in Choyang creek basin susceptible to soil losses based on runoff aggregation structure and energy expenditure pattern of natural river basin within the framework of power law distribution. To this end geomorphologic factors of every point in the basin of interest are extracted by using GIS, which define tractive force and stream power as well as drainage area, and then their complementary cumulative distributions are graphically analyzed through fitting them to power law distribution to identify the sensitive points within the basin susceptible to soil losses with respect to scaling regimes of tractive force and stream power. It is observed that the range of vulnerable region by scaling regime of tractive force is much narrower than by scaling regime of stream power. This result seems to be due to the tractive force is a kind of scale dependent factor which does not follow power law distribution and does not adequately reflect energy expenditure pattern of river basins. Therefore, stream power is preferred to be a more reasonable factor for the evaluation of soil losses. The methodology proposed in this study can be validated by visualizing the path of soil losses, which is generated from hill-slope process characterized by local slope, to the valley through fluvial process characterized by drainage area as well as local slope.

• The Korean Society of Law and Medicine
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• v.19 no.2
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• pp.99-137
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• 2018

Under the Korean law, there are two routes of involuntary civil commitment of the mentally-ill: involuntary commitment process under the Mental Health Act (MHA) and the guardian's commitment backed up by family court approval under article 947-2 (2) of the Civil Code. Despite of the recent fundamental revision of MHA in 2016, the Korean involuntary commitment law has still serious flaws, especially the lack of due process like prior notice, hearing, and independent guardian ad litem for the mentally-ill, which has been pointed out also by the Korean Constitutional Court. Thus, a re-revision is inevitable, and this time, we should proceed to rebuild the underlying structure of involuntary commitment. In this regard, it is crucial to eliminate the old-fashioned and unjustifiable burden as well as power of the so-called responsible person to protect the mentally-ill and to readjust the causes and standings to petition of the various types of involuntary commitment process. Also it is necessary to repeal involuntary commitment by guardian under the Civil Code, article 947-2 (2), which can no longer harmonize with modern involuntary commitment system.

• Steel and Composite Structures
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• v.43 no.1
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• pp.117-127
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• 2022

This study investigates the wave propagation in porous functionally graded (FG) sandwich plates subjected to hygrothermal environments. A new simple three-unknown first-ordershear deformation theory (FSDT) incorporating an integral term is utilized in this paper. Only three unknowns are used to formulate the governing differential equation by applying the Hamilton principle. The FG layer of the sandwich plate is modeled using the power-law function with evenly distributed porosities to represent the defects of the manufacturing process. The plate is subjected to nonlinear hygrothermal changes across the thickness. The effects of the power-law exponent, core to thickness ratios, porosity volume, and the relations between volume fraction and wave properties of porous FG plate under the hygrothermal environment are investigated. The results showed that the waves' phase velocities increase linearly with the waves number in the FGM plate. The porosity of the FG materials plate has a noticeable impact on the phase velocity when considering the high ratios of the core layer. It has a negligible effect on small core layers. Finally, it is observed that changing temperatures and moistures do not influence the relationship between the power law and the phase velocity.

• Strategy21
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• s.33
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• pp.178-201
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• 2014

China National People's Congress has passed the bill to combine the Marine Law Enforcement into "State Oceanic Administration People's Republic of China". This bill was intended to resolve the overlapping jurisdiction and disputes caused in ocean territory in nearby countries. The purpose of reorganizing the administration was to combine the dispersed organization into one group. This new big administration was basically organized to increase the power of China marine state on the long-term. The reorganization plan is to group General Administration of Customs, China Marine Surveillance, Fisheries Law Enforcement Command, and Border Control Department into one State Oceanic Administration. The new state Oceanic Administration carries the authority to protect rights and enforce the marine law supported by Public Security Bureau. Korea Coast Guard has been cooperating with China Marine Surveillance since 1998 when the first pact was made. The next step expanded to General Administration of Customs. Currently working with Regional Maritime Law Enforcement organizations dealing mostly with illegal Chinese fishing boats and IEODO conflict. In order to solve the problems we face today is to observe the process of the New China Coast Guard administration, analysing the effects that could be caused by the change and to keep close cooperation between the new administrations.

• Journal of the Korean Home Economics Association
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• v.48 no.4
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• pp.83-102
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• 2010

This paper investigates whether intra-household bargaining power affects couples' caregiving decisions during instances of competing parental demands for assistance. The primary focus is on examining how partners' bargaining power influences the relative allocation of time resources between parents and parents-in-law, assuming that children prefer to transfer caregiving resources toward their own parents over their parents-in-law. The findings in this study reject the bargaining theory that couple's parental care behavior results from a bargaining process between the husband and the wife. More specifically, the results did not clearly show that children prefer to transfer caregiving resources toward their own parents over their parents-in-law. Decision-making power, measured by final decision-making authority, also failed to affect the relative care transfers.

• Geomechanics and Engineering
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• v.19 no.5
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• pp.421-434
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• 2019

It is of great significance to study the mechanical properties and failure mechanism of the defected rock for geological engineering. The defected sandstone modeling with power-law distribution of pre-cracks was built in this paper by Particle Flow Code software. Then the mechanical properties of sandstone and the corresponding failure process were meticulously analyzed by changing the power-law index (PLI) and the number of pre-cracks (NPC). The results show that (1) With the increase of the PLI, the proportion of prefabricated long cracks gradually decreases. (2) When the NPC is the same, the uniaxial compressive strength (UCS) of sandstone increases with the PLI; while when the PLI is the same, the UCS decreases with the NPC. (3) The damage model of rock strength is established based on the Mori-Tanaka method, which can be used to better describe the strength evolution of damaged rock. (4) The failure mode of the specimen is closely related to the total length of the pre-crack. As the total length of the pre-crack increases, the failure intensity of the specimen gradually becomes weaker. In addition, for the specimens with the total pre-crack length between 0.2-0.55 m, significant lateral expansion occurred during their failure process. (5) For the specimens with smaller PLI in the pre-peak loading process, the concentration of the force field inside is more serious than that of the specimens with larger PLI.