• Steel and Composite Structures
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• v.15 no.2
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• pp.151-162
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• 2013

In this study, an electrolyzing device for the production of metal powders was designed and fabricated. The production of copper powders was performed using a variety of current densities, anode-cathode distances and power removal times. The effect of these parameters on powder particle size and shape was determined. Particle size was measured using a laser diffraction unit while the powder shape was determined by SEM. Experimental results show that an increase in current density leads to a decrease in powder particle size. In addition particle shape changed from globular dendritic to acicular dendritic with increasing the current density. Distance between the cathode and anode also showed a similar influence on powder particle size and shape. An increase in time of powder removal led to an increase in powder particle size, as the shape changed from acicular dendritic to globular dendritic.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.381-387
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• 2008

Neutron production rate in spherically convergent beam fusion(SCBF) device as a portable neutron source strongly depends on the ion current and the grid cathode structure. In this paper, as the process of design and analysis, Design of Experiment(DOE) based on the results by Finite Element Method-Flux Corrected Transport(FEM-FCT) method is employed to calculate the ion current. This method is very useful to find optimal design conditions in a short time. Number of rings, radius of rings, and distance between the grid cathode and center are selected as control factors. From the results in the optimized model, the higher ion current is calculated and deeper potential well is also observed.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.203-214
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• 2022

A model is developed for estimating optimal cultivation areas for apples to maximize the total profit of apple farming by region, focusing on Gyeongsangbuk-do, Chungchungbuk-do, Gyeongsangnam-do, and Jeonllabuk-do in Korea. Comparing the current cultivation areas to the optimal areas according to the model estimation during the period 1999 - 2019, the former has exceeded the latter since 2015 in all regions except for Jeonllabuk-do. This result stems from a lack of the regulation of production quantity among apple producers' regional organizations. Accordingly, the decreasing rate of the market price was greater than the increasing rate of the production quantity, and the total profit of apple farming has fallen in conjunction with increasing agricultural wage rates. Therefore, in order to reverse the current decreasing trend in the profits of apple farming, it is necessary to regulate nationwide apple cultivation areas through regional producers' associations. Ex-ante forecasting for 2019 posits the following regional optimal cultivation areas for maximizing the total income from apple farming. The Gyeongbuk apple producers' association needs to reduce its current cultivation area by 1,089 ha and to maintain 18,373 ha. In the Chungbuk region, current cultivated area should be reduced by 1,027 ha to maintain 2,722 ha, and in the Gyeongnam region, the current cultivated area should be reduced by 582 ha to maintain 2,730 ha. In contrast, the Jeonbuk region needs to increase its current cultivation area by 174 ha and to maintain at a level of 2,872 ha.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.49-56
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• 2013

The entire land of Southern Iran faces problems arising out of various types of land degradation of which vegetation degradation forms one of the major types. The present work introduces a model developed for assessing the current status of hazard of vegetation degradation using Geographic Information System (GIS). This kind of assessment differs from those assessments based on vulnerability or potential hazard assessments. The Sadra watershed which covers the upper reaches of Marharlu basin, Fars Province, has been chosen for a hazard assessment of this type of degradation. The different kinds of data for indicators of current status of vegetation degradation were gathered from collecting of field data and also records of the governmental offices of Iran. Taking into consideration three indicators of current status of vegetation degradation the model identifies areas with different hazard classes. By fixing the thresholds of severity classes of the three indicators including per cent of vegetation cover, biomass production and ratio of actual biomass to potential biomass production, a hazard map for each indicator was first prepared in GIS. The final hazard map of current status of vegetation degradation was prepared by intersecting three hazards in the GIS. Results show areas under severe hazard class have been found to be widespread (89 %) while areas under moderate and very severe hazard classes have been found less extensive in the Sadra watershed. The preparation of hazard maps based on the GIS analysis of these indicators will be helpful for prioritizing the areas to initiate remedial measures.

• Journal of Energy Engineering
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• v.28 no.1
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• pp.65-72
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• 2019

The Korean government is aiming to produce 20% of the electricity using renewable energy sources by 2030. Ocean renewable energy sources which are abundant in South Korea can do an important role to achieve the goal. This paper introduces a tidal current energy converter utilizing flow induced vibrations which can efficiently work even in the currents slower than 1.0m/s and suggests optimal designs of the tidal energy converter based on speeds of the tidal currents in seven different coastal regions in South Korea. Moreover, the theoretical annual energy production by the tidal converter is estimated at theses costal areas. The total amount of the annual energy production by the tidal energy converter is predicted as 221.77 TWh which is equivalent to 42.3% of the electric consumption of South Korea in 2013. The result shows that the tidal current energy converter can be an important role to achieve the goal of the Korean government.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.87-90
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• 2000

This paper has reviewed the China Sericulture history in the 20th century. On the basis of the current sericulture production, sericulture area distribution, problems and challenges, it has been forecasted that China sericulture will be developed as following points: 1) On a stable basis, cocoon production increased gradually to a suitable amount; 2) Quality cocoon production bases established to form a regionalized, industrialized and specialized sericulture structure; 3) With increase of householding rearing capacities, rearing facilities improved; 4) Production efficiency raised and silk product quality improved through technical innovation; 5) New and diversified products developed from Sericultural resources with new and high technologies.

• Clean Technology
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• v.22 no.1
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• pp.62-72
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• 2016

These days, it seems to be a core time to build proactive prevention systems for small and medium sized enterprises due to the reinforced safety in the production process and the strong environmental regulations (ES) both at home and abroad. On the other hand, a network of experts that combines the industrial environment and production safety as well as even the knowledge services companies are not quite enough to prepare to support them. In this study, through a survey of experts the current statue of the convergence of industrial environment and production safety were reviewed, and the structure of knowledge ES cluster was proposed to overcome this current state. Detailed strategies such as the development and distribution of ES convergence methodology, ES efficiency analysis and an ES roundtable.

• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.227-242
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• 2012

Accurate estimation of milk production cost is very important for dairy farmers in establishing strategies for business management (e.g. planning a program for milk production, deciding the size of business and investment, determining the milk price for sale). Since the estimated cost of milk production is used as an important index to determine the basal price of milk in Korea, there has been much interest and debate on the method used to estimate milk production cost among the stakeholder. This study was thus carried out to identify problems in the current methodology for estimating cost of milk production, and to find a better way to improve it. We propose several alternatives and better ways to improve the current method for estimating cost of milk production. Estimation of the income and cost per head should be based on the number of cattle converted to grown cows. Cost estimation per liter of milk should be made for both whole milk and 3.4% milk fat corrected milk. The value of purchased cows and raised replacement heifers should be the same as their market value. The productive life span of cows should be less 4 years, and the terminal or salvage value of cows needs to be 30 to 40% less than her initial value. When calculating depreciation of cows over the productive life span, however, the salvage value should be 0 or 1 Korean won. On calculating labor costs, the farm labor wage corresponding to the average wage of nonfarm industrial workers should be assumed. Beside of these, better estimation procedures for other items are also given. The proposed methods from this study should improve the accuracy of estimation of milk production cost and help to achieve consensus among the stakeholder.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.66-75
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• 2006

Korea animation industry has a face with many difficulties even if the worldwide animation industry is booming stage. The funding of korea animation industry has been getting decreased from the outside which are ordinary investors and government since 'Wonderful Days' showed on the screen in 2003 didn't has enough box-office profits. In this kinds of circumstance, Animation producers should check out the current production system very closely and restructure improvement factors resolutely. It is very important issue that the serious problems that have been repeated in the past like the absence of planning skill and saving time and money through the improvement of production system. Therefore, the purpose of this thesis is to check out the whole production process used in the current 30 animation industry and analyzes problems, show the necessity of the production management program that makes a given condition of the effective production system in 3d animation.

• Advances in Energy Research
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• v.1 no.1
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• pp.13-33
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• 2013

The present work is an attempt to provide an overview, about the status of R&D and current trends in Hydrogen Production using High Temperature Reactors. Bibliographic references from the INIS database, the Science Direct database and the NTIS database were downloaded and analyzed. Ten year data on the subject, published between 2001 and 2010, was selected for the study. Appropriate qued ry formulations on these databases, resulted in the retrieval of 621 unique bibliographic records. Using the content analysis method, all the records were analyzed. Part One of the analysis details Scientometric R&D indicators, Part Two is a subject-based analysis, grouped under: A. International Initiatives and Programmes for Hydrogen Production; B. European R&D initiatives for Hydrogen production; C. National Initiatives and Programmes for Nuclear Hydrogen Production; D. Reactor Technologies for Nuclear Hydrogen production; E. Fuel Developments; F. Hydrogen Production Processes using HTRs and G. Materials Consideration for Nuclear Hydrogen Production. The results of this analysis are summarized in the study.