• Korean Journal of Plant Resources
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• v.10 no.2
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• pp.169-174
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• 1997

This study was conducted to obtain basic information needed to develop the effective weed control method by using thermal weeder which uses LPG as fuel. For survey of weed distribution in herb field, weed species were investigated at two kinds of herb field of Codonopsis lanveolata and Aster scaber located in Hoengseongkun and Hwacheonkun, Kangwondo. In Codonopsis lanveolata field, Digitaria sanguinalis and Persicaria viridis L were dominated. In Aster scaber field, Digitaria sanguinalis and Erigeron canadensis were dominated. In general, Grasses weeds in herb were more dominated than other broadleaf and Cyperaceae weeds. The treatments of $H_2SO_4$ in weed seeds were more effective for germination of several weeds, compared with that nontreated weed seeds. However, the rate of germination differed depending on weed species and tereatment time of $H_2SO_4. Also, viability of weed seeds was significantly affected by irradiation time and temperature. As the temterature and treatment time of irradiation increased, the rate of germination was decreased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.817-822
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• 2017

The braking system is one of the most important components in vehicles and machines. It must exert a reliable braking force when they are brought to a halt. Generally, frictional heat is generated by converting kinetic energy into heat energy through friction. As the kinetic energy is converted into heat energy, high temperature heat is generated which affects the mechanical behavior of the braking system. Frictional heat affects the thermal expansion and friction coefficient of the brake system. If the temperature is not controlled, the brake performance will be decreased. Therefore, it is important to predict and control the heat generation of the brake. Various numerical analysis studies have been carried out to predict the frictional heat, but they assumed the existence of boundary conditions in the numerical analysis to simulate the frictional heat, because the simulation of frictional heat is difficult and time consuming. The results were based on the assumption that the frictional heat is different from the actual temperature distribution in a rotating brake system. Therefore, the reliability of the cooling effect or thermal stress using the results of these studies is insufficient. In order to overcome these limitations and establish a simulation procedure to predict the frictional heat, this study directly simulates the frictional heat generation by using a thermal-structure coupling element. In this study, we analyzed the thermo-mechanical behavior of a brake model, in order to investigate the thermal characteristics of brake systems by using the Finite Element method (FEM). This study suggests the necessity to directly simulate the frictional heating and it is hoped that it can provide the necessary information for simulations.

• Journal of the Korean Home Economics Association
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• v.45 no.9
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• pp.15-26
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• 2007

Immigrant workers in Korea who have a multi-cultural background are increasing a need is arising to support them with housing that considers their housing culture. The purpose of this study is to gather information to formulate a plan of ChoSun-Tribe Immigrant Workers in Korea. For this purpose, we investigated to the usage of domestic space and the seating style of ChoSun-Tribe members in China and Korea. Ethnographic research with a questionnaire was used to analyze 16 households in China and 17 in Korea. The study results were as follows. 1. Most of the ChoSun-Tribe members in China and Korea thought that the kitchen had to be separated from other areas and also they wanted to have a large kitchen in which they can work comfortably. 2. ChoSun-Tribe members in China used a bathroom as a laundry normally while and ChoSun-Tribe members in China and Korea didn't think that a bathtub was indispensable in the bathroom. 3. The most uncomfortable feature for ChoSun-Tribe members in Korea was having to use a toilet outside so a toilet should be considered inside of the house. 4. ChoSun-Tribe members in China and Korea were accustomed to sitting on the floor for their living usually and ChoSun-Tribe members in China used the living room as a multi-purpose room for the family. 5. A modified Ondol system using water pipes under the floor was gaining popularity in China and was the most desirable heating system for ChoSun-Tribe members in China and Korea also. 6. ChoSun-Tribe members in China and Korea all took off their shoes inside of the house for hygienic reasons so the space for taking on-off shoes was indispensable. 7. Housing for ChoSun-Tribe immigrant workers in Korea needs to be planned with a good environment lots of sunshine and better ventilation.

• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.239-247
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• 2005

In this study, we have used newly developed dual-beam shearography which is based on laser speckle that includes various information about an object. Among the several shearing techniques, we used Michelson shearing interference technique which is the most powerful. Acrylate plate was used as a sample, which has inner defects and low thermal conductivity. Michelson shearing interferometer was used for obtaining speckle fringes. We also used phase shifting technique to get a phase map. Using single beam illumination, we could obtain mixture of deformation components of both in-plane and out-of-plane. In order to separate the two components, we have used dual-beam shearography technique. We have obtained a speckle pattern of both before and after deformation. Through LS filtering and unwrapping processes, we could find a position and a shape of the inner defects easily. Deformation of the acrylate plate due to thermal heating has occurred mainly in z-direction(out-of-plane) because it has low thermal conductivity. The acrylate plate was deformed only at the restricted area where the electrical heat applied.

• Journal of Conservation Science
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• v.28 no.1
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• pp.53-62
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• 2012

The archival objects are tangible evidence related to the public service. They are unique and offer information representing the specific events, time or person. The archival objects as modern cultural heritage do not have the guideline to classify, manage and conserve them. Especially, it is difficult to apply general conservation process for burial artifacts, because there are few study example of conservation for metal archival objects and they have complex administrative value. We tried to find suitable material and application method for consolidation of copper alloy archival object. We choose three kinds of wax and acrylic resin for burial artifacts and had done comparative analysis of their characterizations following kinds and coating methods. As a result of evaluation by several surface analysis such as optical microscope, measuring film thickness, adhesive strength, contact angle and yellowing test, acrylic resin can use to archival objects of copper alloy, effectively but the method of heating after dip-coating with Wax B used before can get best effect of consolidation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5D
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• pp.493-498
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• 2012

Korean construction companies have maintained stable market share based on high technology and cost competitiveness although international construction market has been stalled due to increasing global economy uncertainties. However, Korean construction companies have relied heavily on the general types of projects in Middle East and Asia although the portion of different types of projects such as Build-Transfer-Operate (BTO), Build-Transfer-Lease (BTL), and Public-Private-Partnership (PPP) has been increasing in the market. When delivering huge projects requiring contractors deal with activities from project planning to operation, securing finance sources and profitability is deemed critical. Therefore, Korean construction companies need more attentions on the construction market supported by Multilateral Development Banks. However, Korean construction companies have not utilized effective strategies for the market entry and also government supportive policies are not useful enough to help construction companies. This study aims both to analyze the contract structure of Korean construction companies for presenting critical factors that need to be prepared and to suggest various methods that can be applied to support construction companies that have much interest in the Multilateral Development Banks. According to the results of study, it is important that Korean government provide structural information system, make a specialized organization, prevent over-heating among Korean construction companies, and collaborate with Official Development Agency. In addition, it appeared that the fairness and financial stability of project have recognized main advantages of the Multilateral Development Banks.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.477-482
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• 2007

Forest biomass became a topic because we have growing interest in global environmental issues and environment-friendly energy resources. This study was carried out to estimate the forest biomass and develop a program for biomass information management in Korea. The total forest biomass (million ton) were 521 for gross forest, 403 for productive forest and 201 for commercial forest in 2005. Also, the annual biomass production in forest was 20 million ton which was equivalent to 94,290 Gkcal of heating value and about 9 billion won of paraffin oil. The biomass growing rate (every 10year) increased from 4.95% in 1985 to 5.30% in 1995 but turn down 4.46% in 2005. The factors that the forest stock could be converted to the forest biomass have developed according to forest type. Therefore, it is impossible to estimate the exact biomass by tree species. In this reason, the demands of the development of the factors by tree species was raised. In addition, it is on time to develop an equation for estimation of biomass by species using dbh and height as independent factors.

• Journal of Adhesion and Interface
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• v.3 no.4
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• pp.1-9
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• 2002

The main goal of this study was to analyze the effect of process additives, i.e. maleated polypropylene (MAPP), and nucleating agent on the viscoelastic properties of different types of extruded polypropylene-wood plastic composites manufactured from either PP homopolymer, high crystallinity PP or PP impact copolymer using dynamic mechanical thermal analysis. And also, the esterification reaction between wood flour and maleated polypropylene, and its role in determining the mechanical properties of wood flour-polypropylene composites was investigated. The wood plastic composites were manufactured using 60% pine wood flour and 40% polypropylene on a Davis-Standard $Woodtruder^{TM}$. Dynamic mechanical thermal properties, polymer damping peaks(than ${\delta}$), storage modulus (E') and loss modulus (E") were measured using a dynamic mechanical thermal analyzer. XPS (X-ray Photoelectron Spectroscopy), also known as ESCA (Electron Spectroscopy for Chemical Analysis) study of wood flour treated with MAPP was performed to obtain information on the chemical nature of wood fiber before and after treatment. To analyze the effect of frequency on the dynamic mechanical properties of the various composites, DMA tests were performed over a temperature range of -20 to $100^{\circ}C$, at four different frequencies (1, 5, 10 and 25 Hz), and at a heating rate of $5^{\circ}C/min$. From these results, the activation energy of the various composite was measured using an Arrhenius relationship to investigate the effect of maleated PP and nucleating agent on the measurement of the interphase between the wood and plastic of the extruded polypropylene wood plastic composites.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.83-92
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• 2014

This paper attempts to conduct a comparative analysis on the economic effects of integrated-energy and manufactured gas supply sectors. To this end, an input-output (I-O) analysis is applied using most recently published 2011 I-O table. In particular, the two sectors are specified as exogeneous to identify the economic effects on own and other sectors. Production-inducing effect, value-added creation effect, and employment-inducing effect are quantified based on demand-driven model. Supply shortage effect and price pervasive effect are analyzed employing supply-driven model and Leontief price model, respectively. The results show that production-inducing effect, value-added creation effect, and employment-inducing effect of integrated-energy and manufactured gas supply sectors are estimated to be 1.5461 vs. 1.0297, 0.4759 vs. 0.1941, and 2.2885 vs. 0.4053 respectively. Price pervasive effects of the 10% increase in integrated-energy and manufactured gas supply sectors are computed to be 0.0127% and 0.1585%, respectively. This information can be utilized in forecasting the economic effects of introducing integrated-energy or manufactured gas as a heating source and the impacts of a rise in price of integrated-energy or manufactured gas on price level of other sectors.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.245-252
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• 2016

Purpose: To provide the public with nutritional information on consumption types of garlic, we evaluated the influence of heat treatment method on the nutritional contents of different species of garlic. Methods: We determined the content of general components, minerals, vitamins, and fatty acids in each species of garlic produced in Seosan and Goheung by heating with blanching or microwave roasting. Results: The results of the two-way analysis of variance test indicated that the species in particular, as well as method of heat treatment and interaction, had an influence on nutritional content. The moisture and crude fat content was higher in Southern type garlic than in Northern type garlic, while crude proteins, crude ash, and dietary fibers were more abundant in Northern type garlic than in Southern type garlic. With regard to the total mineral content, K, P, Mg, and Ca were the main components in Northern type garlic and Southern type garlic. Moreover, unsaturated fatty acids showed high levels in both Northern type garlic and Southern type garlic, with more abundant linoleic acid. Overall, Northern type garlic showed a higher content of minerals and fatty acids, while more vitamin B was present in Southern type garlic. In addition, the results indicated that the content of general components (dietary fiber excluded) was increased in both Northern type garlic and Southern type garlic upon heat treatment. Blanching resulted in increased mineral and fatty acid content in Southern type garlic and decreased content in Northern type garlic, indicative of species differences; conversely, microwave roasting contributed to an increase in the content in both Northern type garlic and Southern type garlic. Conclusion: The nutritional content of garlic is more dependent on species than the cooking method, and grilling is associated with less nutrient loss than blanching.