• 환경영향평가
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• 제12권4호
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• pp.291-302
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• 2003

This paper examined the impacts of the regional developments and dwellers behavior on the Seacoast. Seacoast features a variety of landforms which are created by the action of waves and tidal flows. The coastal landforms are found mainly in the interface between land and sea. Although erosional landforms constitute prominent landscape features as sea stack, sea arch, and rock cliff do, it is nonetheless the depositional features such as beaches, tidal flats, offshore bars, deltas, sanddunes, and coastal plains that have various ramifications for human communities. Among these, beaches and coastal sanddunes are special in that their formation is attributable to the combined action of waves, tidal flows, and winds. The main line of discussion in this dissertation is concerned with the transformation of group of beaches sanddunes along the coastline of Chungcheong-Namdo Province. To some extent, the erosion of coastal dunes has been a global phenomenon. The degradation process occurs most actively when the spring tides attack beaches, berms, and foredunes. Also involved in the transformation of coastal dunes are factors of human agency. The extent, speed, and pattern of their morphological changes are a function of land-use pattern. The reclamation of swale and the exploitation of sands as construction material and silica sand, for example, ruin the feature of coastal dunes.

• 유통과학연구
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• 제17권2호
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• pp.13-23
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• 2019

Purpose - Corporate activities for enhancing and improving corporate performance can largely be divided into exploration and exploitation. The purpose of this study is to examine the impact of implementing organizational ambidexterity in SMEs, including distribution firms, by reviewing the extant literature and deriving the basis on which this strategy affects the managerial performance. Research, design, and methodology - The study uses a systematic review methodology, which employs a structured process to discern trends and meaningful themes across a wide body of literature on specific subjects and research questions. This qualitative study examined the influence of ambidextrous strategies of SMEs on firm performance, and the results were synthesized from the literature. Results - Organizational ambidexterity in SMEs is related to the firm's managerial performance. However, it is crucial to know that there are many ways to generate an ambidextrous organization, and decisions about what method to choose should be based on the environmental aspects of the enterprise. Conclusions - The following aspects should be considered for execution; : making practical decisions based on accurate information about the resources the firm has, considering the organizational level of human resources for implementing organizational ambidexterity, and sharing specific performance goals.

• 기술사
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• 제38권6호
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• pp.1-9
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• 2005

The Republic of Korea (South) and the Peaples Republic of Korea (North) had agreed to exploit the North Korean rich natural resources starting from the year of 2006. Through this mutual agreement DPRK shall quarantee ROK's investment in the North Korean Mines and supply mineral products for the compasation of the financial investment supported by ROK. In the area of northern part of Korea, many kind of natural resources such as Magnesite, Iron, Gold & Silver, Copper, Lead & Zinc, and Coal are plentifully deposited. In the area of southern part of Korea, however, most kind of natural resources have been exhausted and so presently major minerals such as Gold & Silver, Copper, Lead & Zinc and Coal are being imported and relying on foreign countries in whole quantity of the requirement. On the other hand Northern Part of Korea is making very slow progress in mining and exploitation owing to the lack of investment even though there are rich deposits of natural resources. And in Southern Part of Korea, they have most advanced production facilities and technologies in the world in the fields of Mineral Floatation, Steel Manufacturing, Nonferrous Metal Smelting & Refining and those plants fabrications. A combination of Southern Technologies together with Financial Support and Northern rich natural resources & Labour Power will be a most hopeful, desirable and mutually required 'South-North economic Cooperation' as the mining industries are labour intensive.

• Advances in Energy Research
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• 제7권1호
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• pp.35-52
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• 2020

The paper proposes a hybrid approach of artificial bee colony (ABC) and grey wolf optimizer (GWO) algorithm for multi-objective and multidimensional engine optimization of a converted plug-in hybrid electric vehicle. The proposed strategy is used to optimize all emissions along with brake specific fuel consumption (FC) for converted parallel operated diesel plug-in hybrid electric vehicle (PHEV). All emissions particulate matter (PM), nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) are considered as optimization parameters with weighted factors. 70 hp engine data of NOx, PM, HC, CO and FC obtained from Oak Ridge National Laboratory is used for the study. The algorithm is initialized with feasible solutions followed by the employee bee phase of artificial bee colony algorithm to provide exploitation. Onlooker and scout bee phase is replaced by GWO algorithm to provide exploration. MATLAB program is used for simulation. Hybrid ABC-GWO algorithm developed is tested extensively for various values of speeds and torque. The optimization performance and its environmental impact are discussed in detail. The optimization results obtained are verified by real data engine maps. It is also compared with modified ABC and GWO algorithm for checking the effectiveness of proposed algorithm. Hybrid ABC-GWO offers combine benefits of ABC and GWO by reducing computational load and complexity with less computation time providing a balance of exploitation and exploration and passes repeatability towards use for real-time optimization.

• Environmental Engineering Research
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• 제15권2호
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• pp.85-91
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• 2010

Romania aims to adopt and implement the European Union's legislation, also including that for the field of water management. Like other countries, groundwater in Romania is locally polluted from point sources, such as leaking landfills, as well as from diffuse pollution sources, include fertilizers, pesticides and leakages from sewers, in urbanized areas. Diffuse pollution can also occur indirectly, by over-exploitation of groundwater wells, resulting in salt water intrusion, as well as from mining and exploitation of mineral aggregates. Romania has quite an intensive monitoring scheme to measure groundwater quality in phreatic and confined aquifers. The purpose of the work resumed in this paper was to derive natural background levels (NBL) for groundwater in order to distinguish the natural elevated concentrations of some substances (natural phenomena) from point and diffuse pollution (anthropogenic phenomena). Based on these NBLs, threshold values (TV) for groundwater will be set according to the requirements of the European Water Framework Directive and the related Groundwater Directive. This paper describes the results of a study for the derivation of NBL and TV in a pilot Groundwater Body. Also, the process and draft results for extrapolating this work for all Romanian groundwater bodies is explained, as well as points for future consideration with respect to monitoring and management.

• 마이크로전자및패키징학회지
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• 제8권2호
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• pp.43-48
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• 2001

Economical consumption of energy, longer life of lamps, higher lighting comfort and new aesthetic of illumination is subject of numerous research and development works. The halogen lamps are an example of positive solution some of above mentioned problems. The electronic transformers are more frequent used for their supply. In comparison with conventional transformers they have less weight, less volume and 60% less power losses. Their advantages are particular visible, when the hybrid technique is applied. The paper presents the results of engineering research and development works carried out in Private Institute of Electronic Engineering, in R. & D. Center for Hybrid Microelectronics and Resistors and in Technical School of Communications in Krakow, in the field of the design and exploitation tests of hybrid converters 220V AC /12V DC (electronic transformers) and electronic ballasts destined for the supply of halogen lamps 20W to 150W and fluorescent lamps respectively. To perform the converters, thick film technology and surface mount technology were used. For the protection of converter electronic circuit the thick film temperature sensor and transistors were applied. Moreover the paper presents the base application circuits of elaborated converters, their technical parameters and exploitation results. The development perspectives of such domain of hybrid circuits are also discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.775-782
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• 2004

Recently, the cases which are constructed close by neighboring structure or underground structure are on the increase to get the utmost out of the land exploitation of underground space in the downtown area. As the building becomes larger, the excavation depth is getting deep, and the excavation area is getting, wide too. These are frequent occasions that the application of Strut or Anchor method is difficult, because of site boundary, civil application and the ground condition. Therefore, to solve these problem, we analyze and compare design with measuring data, change the design factor and show the improvement of course through the application of self-supported diaphragm wall using counterfort technique which is a new method. It is expected to be a contribution to the suitable exploitation method of construction.

• Journal of Communications and Networks
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• 제16권3호
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• pp.280-292
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• 2014

This article presents a novel cooperative spectrum sharing (CSS) scheme. The primary transmitter transmits a complex Quadrature amplitude modulation (QAM) signal in the first phase, and CSS occurs in the second phase. The secondary transmitter with the largest forwarding channel gain among the nodes that successfully decode the primary signal in the first phase is selected for CSS. This selected node employs a pulse-amplitude modulation (PAM) signal for primary information message (IM) instead of the QAM signal, and it employs a modified PAM signal for the secondary IM. The proposed modified PAM signal depends on the amplitude of the primary PAM signal. This method results in no mutual interference and negligible primary interference constraint and allows a higher degree of exploitation of spatial diversity, thus enabling increase in secondary power to improve primary transmission. The outage performance is enhanced in both the primary and secondary systems. The critical region, in which the primary outage performance is enhanced with the proposed CSS scheme, can be adjusted and widened by varying either the modulation cooperation sharing factor or the number of secondary transmitters.

• Computers and Concrete
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• 제14권1호
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• pp.91-107
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• 2014

Using the principle of damage mechanics, zero-thickness pore pressure cohesive elements (PPCE) are used to simulate the casing-cement interface (CCI) and cement-rock interface (CRI). The traction-separation law describes the emergence and propagation of the PPCE. Mohr-coulomb criteria determines the elastic and plastic condition of cement sheath and rock. The finite element model (FEM) of delamination fractures emergence and propagation along the casing-cement-rock (CCR) interfaces during hydraulic fracturing is established, and the emergence and propagation of fractures along the wellbore axial and circumferential direction are simulated. Regadless of the perforation angle (the angle between the perforation and the max. horizontal principle stress), mirco-annulus will be produced alonge the wellbore circumferential direction when the cementation strength of the CCI and the CRI is less than the rock tensile strength; the delamination fractures are hard to propagate along the horizontal wellbore axial direction; emergence and propagation of delamination fractures are most likely produced on the shallow formation when the in-situ stresses are lower; the failure mode of cement sheath in the deep well is mainly interfaces seperation and body damange caused by cement expansion and contraction, or pressure testing and well shut-in operations.

• Ocean and Polar Research
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• 제29권2호
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• pp.165-185
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• 2007

Exploitation of transboundary oil and gas on continental shelves may cause conflicts between or among States concerned due to the physical character of these resources. As oil and gas are fluid, exploitation of such a transboundary oil field by one side may affect other parties in other jurisdictions. However, there is no universal international legal regime on the issue. This article tries to find the international legal regime governing such resources through analysing UN Assembly's resolutions, UNCLOS, international judicial opinions, bilateral agreements and ILC activities relating to transboundary natural resources. As a result of this study, it seems that each coastal State has an inherent sovereign right on its part of the transboundary oil and gas deposit, but this right is not unlimited. Each state involved with the deposit has a duty to cooperate with other states-through information exchange, consultation, and negotiation. Furthermore, the state has an obligation to refrain from unilateral action when there is a possibility of causing irrevocable damage to the interests of the other states.