• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.4
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• pp.69-79
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• 2014

Coastal wetlands are among the most productive biomes in the Earth. The economic values include the direct use of a coastal wetland's ecosystem services, such as food, raw materials, recreation, and tourism. Other values comprise the indirect use of a coastal wetland's ecosystem services, such as carbon sequestration, waste-water treatment, and erosion prevention. In particular, Suncheon Bay is recently attracting attention as the most successful case of the preservation and restoration. This study applies Travel Cost Method (TCM) to estimate the economic value by drawing the demand curve for trips to Suncheon Bay. The TCM is an approach used for economic valuation of non-market goods and services. Based on the results of TCM, this study shows that the economic benefit from recreational uses of the site adds up to \174.7 billion per year. It is also significant in the sense that monetary information is suggested to help local policy makers evaluate the realistic values of coastal wetlands.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.7
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• pp.1119-1127
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• 2007

Nonwovens have been widely used in various regions from the households to the industrial, agricultural and medical goods. Synthetic fibers have been used for source of nonwovens commonly because of their useful and economic properties. They are not only main factor causing environmental problems but also spend huge cost to renew the environmental disruption by them. Nonwovens must have both cost-competitiveness and environment-friendly property to be the desirable sources in 21th centuries. For meet these needs, it is suitable for the times that economical and environmentally-safe kenaf fibers would be used as raw materials of nonwovens. Kenaf and polyester fibers were blended in 4 types of ratio : 0/100, 20/80, 40/60, 60/40 were needle-punched. The nonwovens properties such as color values, surface appearance, strength, elongations, stiffness, moisture regain, water and oil absorbency, and electrification were tested. As the results, tensile and tear strengths, water and oil absorbency were maximum at 20/80 kenaf/polyester blend nonwoven, because of effecting by nonwoven structure and fiber properties. The moisture regain were increased according to kenaf were blended and the eletrification reduced in proportion to the kenaf fibers by chemical property of fiber composed nonwovens.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.5
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• pp.407-412
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• 2003

An effective methodology is .reported for determining the optimal capacity (lot-size) of batch processing and storage networks which include material recycle or reprocessing streams. We assume that any given storage unit can store one material type which can be purchased from suppliers, be internally produced, internally consumed and/or sold to customers. We further assume that a storage unit is connected to all processing stages that use or produce the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. The objective for optimization is to minimize the total cost composed of raw material procurement, setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory hold-up. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two subproblems. The first yields analytical solutions for determining batch sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks. For the special case in which the number of storage is equal to the number of process stages and raw materials storage units, a complete analytical solution for average flow rates can be derived. The analytical solution for the multistage, strictly sequential batch-storage network case can also be obtained via this approach. The principal contribution of this study is thus the generalization and the extension to non-sequential networks with recycle streams. An illustrative example is presented to demonstrate the results obtainable using this approach.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.355-362
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• 2001

This study was conducted to propose the way to develop and strengthen competitiveness of the Korean paper industry by analysing current competitiveness and the factors which determine and influence it. Delphi method was employed to identify determining factors of international competitiveness of Korean paper industry and evaluate the level of competitiveness. The competitiveness both in the domestic and foreign markets was evaluated by analysing each product market faced by the Korean paper industry in light of each of the determining factors. Based on the Delphi survey results, in order of importance, product quality, manufacturing cost, transportation and storage, timely delivery, supply of raw materials, and marketing were identified as the factors determining international competitiveness. Among them, it was revealed that Korean paper industry has a certain level of competitiveness in the factors such as product quality and timely delivery service while supply of raw materials and manufacturing costs were found to be inferior to overseas manufacturers in both domestic and foreign markets.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.15-24
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• 2015

Currently, abundant wastes from the palm oil refining process have been generated which are hard to handle. Spent Bleaching Earth (SBE) is the solid waste from this process and leads the cost of elimination to the company. This study aims to utilize the SBE as the alternative material in the non-fired wall tiles. The main raw materials used in non-fired wall tiles consist of laterite soil, fluvial sand, and Portland cement. The experimental formulas have been conducted and divided into 3 groups by varying the percentage of the SBE in main raw materials. The specimens of material mixture have been produced by uniaxial pressing at 100 bars, dimensions in $50{\times}100{\times}8mm$. These specimens are sprayed with water and cured in the air for 7 days. After that, bending strength and water absorption test of these specimens has been performed. It can be concluded that the best formula with the percentage of laterite soil, fluvial sand, Portland cement, and SBE are 60.94%, 13.125%, 22.5%, and 3.435%, respectively. Its bending strength and %water absorption are 0.68 MPa and 5.64%. Material costs of specimen are approximately $0.00276 USD/100g. Furthermore, the comparison of curing period between 7 days and 30 days has been performed. The 30 days of curing period can improve the bending strength of the specimen, but there is no effect on water absorption.

• Journal of the Korean Society of Costume
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• v.65 no.2
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• pp.125-143
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• 2015

This study is to propose an 'education-training-certificate of qualification' design of fashion accessories production, which can be applied to education in universities and individuals. It is based on the National Competency Standards (NCS), which was developed through the '2013 National Competency Standards Development Project' for the fashion accessories production. FGI (Focus Group Interviews), which is a research methodology, is carried out on target groups of educational experts and specialists in the field of fashion accessories production. Through this, five courses were suggested; first, 'fashion accessories design' course was proposed for the education and training of 'design development' and 'development of raw materials'. Secondly, 'fashion product production' course was proposed for the education and training of 'production of samples'. Thirdly, 'fashion product manufacture and planning' course was proposed for the competency element units: 'calculation of cost', 'determination of mass production model and price', 'planning of the main manufacturing process' and 'ordering of raw materials'. Lastly, 'mass production of fashion products' course and the 'field practice of fashion product manufacture' course were proposed for the competency element units: 'planning for mass production', 'preparation for mass production', 'mass production' and 'inspection of completed products'. In addition, a new certificate of 'technician of fashion accessory production' was proposed in order to test qualified skills for the fashion accessories production. The test is composed of a written examination of short-answer questions, technical drawing and production.

• Transactions of Materials Processing
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• v.31 no.3
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• pp.129-135
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• 2022

The purpose of this study was to quantitatively evaluate the influence of hardness of tool materials on wear resistance in the sheet metal forming process. Punches used in the wear test were made of STD-11 and K340 tool material, and the tempering temperature was set to 530℃ and 500℃, respectively, to control the hardness of the tool materials. The punches mimic the shape of stamping tool of automotive body component to reflect its plastic deformation, and are designed to concentrate wear on the curvature region of punches. Progressive die and coil sheet were used to save time, cost, and raw sheet materials. By quantitatively measuring the wear depth of the punches, the wear behavior and mechanism of the punches were investigated, and characteristics of hardness and wear resistance according to tool materials and tempering temperatures were evaluated. Testing results indicate that the punch made of K340 tool steel with higher hardness had better wear resistance than that of STD-11 tool steel, and the hardness and wear resistance of tool steel were significantly impacted by the tempering temperature.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.181-185
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• 2005

We investigated the fermentative production of lactic acid from cheese whey and corn steep liquor as cheap raw materials using Lactobacillus sp. RKY2 to reduce the manufacturing cost of lactic acid. Lactic acid yields were obtained at more than 0.98 g/g from medium containing whey lactose. Lactic aid productivities and yields obtained from whey lactose were slightly higher than those obtained from pure lactose. The final concentration of lactic acid increased with increase, in whey lactose concentration, whereas the lactic acid productivity decreased probably due to substrate inhibition. The fermentation efficiencies were improved by addition of more corn steep liquor to the medium.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.53-62
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• 2012

In the past, poultry nutrition has focussed on increasing the production efficiency to meet the progress achieved in the genetic potential of broilers and layers. Future directions in poultry nutrition will be driven by not only by the need to maximise biological and economic performance of birds, but also by societal issues (environment, antibiotic growth promoters, welfare, traceability and use of genetically modified ingredients). Key advances in poultry nutrition are discussed and future directions, which can be expected, are highlighted. Given the tightening supply and ever-increasing cost of raw materials, there will be more pressure to extract every unit of energy and nutrients from feed ingredients. In this context, a number of feed additives are expected to play an increasingly significant role. Feed enzymes and crystalline amino acids, in particular, will have a profound effect on future sustainability of the poultry industry. Future nutritional research need to focus on identifying the barriers to effective digestion and utilisation of nutrients and, to achieve this objective, nutritionists must combine their expertise with those of specialising in other biological sciences, including immunology, microbiology, histology and molecular biology.

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.31-35
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• 2016

This study was conducted to test whether post-harvest medium of king oyster mushroom can be recycled for its bottle cultivation. Physical properties of the post-harvest medium and the resulting yield of fruit bodies revealed no significant difference compared with control. Recycling post-harvest medium can be replaced to 15% of the basal medium, thus decreasing the cost of raw materials up to 15%.