• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.142-148
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• 2006

Hydraulic excavators have been popular devices in construction fields because of their multi-workings and economic efficiency. The mathematical models of excavators have many nonlinearities because of opening characteristics and dead zone of main control valve(MCV), oil temperature variation, etc. The objective of this paper is to develop a simulator for hydraulic excavator using AMESim. Components and their circuits are expressed graphically. Also, parameters and nonlinear characteristics are considered in a text style. From the simulation results, fixed spring stiffness of MCV can not obtain the satisfactory accuracy of spool displacement under whole P-Q diagrams. Closed loop type MCV containing a proportional gain, is proposed in this paper that can reduce displacement error. The ability of closed loop MCV is verified through comparing with normal type MCV using AMESim simulator. The excavator simulator can be used to forecast the attachment behaviors when components, mechanical attachments and hydraulic circuits change, or other control algorithms are applied. The simulator could be a kind of development platform for new excavators.

• Transactions of The Korea Fluid Power Systems Society
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• v.2 no.1
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• pp.9-14
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• 2005

Hydraulic excavators have been popular devices in construction field because of its multi-workings and economic efficiency. The mathematical models of excavators have many nonlinearities because of nonlinear opening characteristics and dead zone of main control valve, oil temperature variation, etc. The objective of this paper is to develop a simulator for hydraulic excavator using AMESim. Components and whole circuit are expressed graphically. Parameters and nonlinear characteristics are inputted in text style. The simulator can be used to forecast excavator behavior when new components, new mechanical attachments, hydraulic circuit changes, and new control algorithm are applied. The simulator could be a kind of development platform for various new excavators.

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.10a
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• pp.1-23
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• 1998

Sustainable agriculture in Korea will gain important momentum by implementing The Direct Payment Scheme for Environmentally Friendly Agriculture in 1999. The farmers who want to participate in the program will be paid 530,000won/ha directly by the Government in return for engaging sustainable agriculture. The policy scheme which is a pilot program will be restricted to environmentally regulated areas to apply such as water supply protection zone, environmental protection districts and national parks. As a consequence of the policy, the supply of transitional organic agricultural products is expected to increase significantly. However the increased supply of low input agricultural products may have difficulties to find an appropriate marketing channel which is differentiated from the general agricultural product market. Development of an open market system for mass transaction of the low imput agricultural products is necessary. Also various government programs and projects which are designed for clean environment and regional community development must be integrated into the sustainable agriculture program to have synergy effects.

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.185-193
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• 2009

This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.

• International Area Studies Review
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• v.22 no.3
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• pp.3-27
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• 2018

This paper analyzes Cuba's market-oriented reforms to alleviate essential problems with socialist countries such as soft budget constraints and incentive problems. It also discuss about effectiveness of industrial policy as a development strategy. The soft budget constraints and incentive problems resulted in the collapse of Soviet bloc and COMECON in early 1990s. After the collapse, Cuban economy suffered a steep dive, and national income tumbling down rapidly. Cuban faced serious shortages of food, gasoline, and other basic necessities of life. To halt and partially reverse economic downturn and dire austerity in the 1990's, the Cuban government made some partial reforms to the inherited Soviet system of cental planningand faced severe shortage in food, energy, and daily necessities. In response to the economic crisis. Cuba introduced economic reforms and implemented industrial policy as a development strategy as long as Cuba maintained a strong socialist country. Cuban government established the economic free zone law and attempted to induce foreign direct investment by implementing export-led industrial policy. Fiedel Castro approved the Law No. 165 "Free Zones and Industrial Parks", in 1996. However, Cuba's ESZ strategy seems to have failed because of the U.S. sanctions, but also because of Cuba's own policies, which do not allow foreign investors to hire workers directly and impose a high implicit tax on wages. By limiting advanced techniques of personnel and organization management, indirect employment can result in lowering work efforts and productivity of workers, and aggravating production efficiency in the ESZs. Another reason to fail comes from the double wage structure due to the double monetary-exchange rate system. Most of the high non-wage costs result from the double exchange rate system. Due to Cuba's imbalanced industry and production structures, concentrated labor force, and urbanization and centralization of agriculture production, the industrial transformation development model suggested by Lewis has not been successful unlike other Asian agriculture-led development model. Cuba has to overcome many difficulties in implementing industrial policy as a development strategy.

• International Area Studies Review
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• v.20 no.4
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• pp.73-90
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• 2016

Recently China's economy has been entered a new normal state with mid-speed growth. Along with the new normal state, Chinese government presented new development strategies. Among them, Beijing-Tianjin-Hebei Integration Strategy(BTH) has become the primary policy on the list of national economic development plan, and the BTH is expected to be the new model of regional development in China. With this background, this article firstly explains the concept and development process of the BTH, secondly presents the state of regional economies, lastly introduces some challenges ahead in the process of the BTH. The challenges, including industry structure adjustment problem, poverty belt in Hebei, environment problem and the distribution of functions of Beijing as a capital, are difficult to solve in a short period. It is needed more cooperative measures between central and local governments to cope with the challenges.

• Journal of the Korean Geographical Society
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• v.39 no.2
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• pp.229-240
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• 2004

This article aimed to suggest a program for environmental protection and sustainable development in southwest Primorskii Krai of the Russian federation by analysis of Natural conditions, natural resources and current economic activities. Issues relating to protecting unique biodiversity toward economic development are examined. Special attention is given to functional zoning of the Russian part of lower Tumen River drainage. Functional zoning is key to protecting the unique biodiversity found in wet and marshlands of the lower Tumen River. Recommendations for acceptable economic activity are provided. The major components for a Sustainable Development Program in this area are: to define economically effective and ecologically acceptable types of regional activity (aquaculture; deer farming; recreation) and effective forms of territorial organization; to determine the restrictions on regional industrial and economic development; to organize rational regional land use by carrying out functional zoning and by coordinating this activity with all land users, including restructuring existing protected territories into a single system and include it into an international biospheric network.

• Animal Systematics, Evolution and Diversity
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• v.28 no.2
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• pp.105-116
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• 2012

Based on samples collected from the Korean Exclusive Economic Zone (EEZ) during an investigation of fishery resources by the National Fisheries Research and Development Institute (NFRDI) from 2002 to 2010, alongside some supplemental material, six species of the genus $Plesionika$ are identified: $P.$ $izumiae$ Omori, 1971, $P.$ $ortmanni$ Doflein, 1902, $P.$ $grandis$ Doflein, 1902, $P.$ $lophotes$ Chace, 1985, $P.$ $narval$ (Fabricius, 1787), and $P.$ $orientalis$ Chace, 1985. Of these, the last four species are new to Korean marine fauna. The distributional range of $P.$ $narval$ extends to the East China Sea off Jeju Island. Excluding $P.$ $izumiae$ and $P.$ $ortmanni$, the other four species are relatively rare in the seas around Korea. They are described and illustrated with color photographs. A key to the Korean species of $Plesionika$ is also presented.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.10
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• pp.13-23
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• 2018

"Special Act on the Rocal Collaborative Development", proposed by Seoul in late 2015, aims to promote win-win cooperation between local economic players and the development of local communities. However, since it is not possible to ensure its effectiveness by signing a local collaborative agreement, the rights and duties granted to the Parties to the Convention shall be more clearly defined. In addition, it is feared that the application of a uniform standard to businesses that wish to restrict the operation within the local collaborative development zone could prevent the operation restriction based on local characteristics. Accordingly, based on the FBR system in the U.S., it is possible to define the business as a "uniform store" and to determine the possibility of a uniform store to be sold through zoning plans in the region by the Local Collaborative Community Council.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1506-1514
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• 2022

Allergic contact dermatitis (ACD) is an allergen-specific T-cell-mediated inflammatory response, albeit with unclear pathogenesis. Exosomes are nanoscale extracellular vesicles secreted by several cell types and widely distributed in various biological fluids. Exosomes affect the occurrence and development of ACD through immunoregulation among other ways. Nevertheless, the role of exosomes in ACD warrants further clarification. This review examines the progress of research into exosomes and their involvement in the pathogenesis, diagnosis, and treatment of ACD and provides ideas for exploring new diagnostic and treatment methods for this disease.