• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.6
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• pp.13-22
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• 2006

The purpose of this study is to propose rational methods in order to maintain vegetation condition and soil environment based on the analysis of tree growth in relation to the soil environment, which is one of the most significant environmental factors on vegetation condition in urban parks and open spaces. The result of the study can be described as below;The soil on every study site had strong acidity. In particular, study sites around industrial district and central business district showed extreme soil acidity. Therefore, soil management system is needed in urban parks and green spaces around those areas. Among Cambium Electric Resistance classified by locations of urban parks and open spaces, one in the costal area was the lowest. The Cambium Electric Resistance in the industrial area was the highest. Therefore, soil condition and locational environment in the industrial area are highly related to the Cambium Electric Resistance. Among the factors, which affect Cambium Electric Resistance in different locations, inorganic content was found to be the main factor in all of the study sites. Inorganic content was an important factor to the Cambium Electric Resistance in study sites located in industrial and central business districts. In the study sites located in costal area, Soil acidity was found to be other important factors that affect Cambium Electric Resistance. To improve the soil acidity, soil buffering ability should be improved from activating microorganisms in the soil by using lime and organic material, Since it takes a long time to make a change in the soil structure, well planed maintenance system is required by mid-term or long-term plans.

• Journal of Korean Public Health Nursing
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• v.28 no.2
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• pp.310-319
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• 2014

Purpose: The purpose of this study is to examine the effects of a resistance band training program on body composition, physical fitness, and health promotion behavior in nursing students. Method: This study has a one-group pretest-posttest design to examine the change in body composition, physical fitness, and health-promoting lifestyle profile after participation in the resistance band training program. Training consisted of hands-based exercises using an elastic resistance band for ten weeks. Participants performed the resistance band training two days per week with a sports trainer, and 30 minutes self-training three days per week. The participants were 21 freshmen in nursing. Results: Mean age of the participants was 20.9 years, and 61.9% were not satisfied with their body shape. After the training program, muscle mass, muscular endurance, and balance of the body were significantly improved. In health promoting lifestyle profile, categories of physical activity, health responsibility, and stress management showed a significant increase. Conclusion: Results of this study suggested that exercising with a resistance band improved body composition, physical fitness, and health promoting behavior in the nursing students. We propose that resistance band training should be suitable for those who have the environment with limitation of time and space.

• Magazine of the Korea Concrete Institute
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• v.20 no.5
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• pp.22-25
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• 2008

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.311-314
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• 2008

While relevant fields of construction industry have rapidly changed, the adaptation (skill) level of individuals to apply or utilize them has slowly followed. By understanding how individuals resist and conform under this change of construction industry and which factors are important for the adaptation, much time, effort, and cost can be saved for organization operation and management, and these saved resources will be able to be effectively invested to others. Accordingly, for construction industry it is necessary to understand and study how the users fit into the rapid technological change. Through this research, therefore, a systematic guideline should be created for the relevant fields of construction industry. For this research, the characteristics of individual personalities and behaviors based on the traditional model was observed and factors that contribute to the resistance and their mutual relations were theoretically identified and categorized, and then a conceptual and figurative model to show the mutual relation between the identified resistive factors was suggested.

• Journal of Digital Convergence
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• v.17 no.9
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• pp.115-126
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• 2019

This study is a survey of people who are return to farming on the intention of accepting ICT convergence technology in agriculture. The research targets were 218 people based on convenience and judgment sampling methods, and the exploratory factor analysis and multiple return analysis were performed with SPSS 22.0. As a result, the independent variables such as performance expectation, effort expectation, and social influence had a positive effect on the acceptance intention of ICT convergence technology in agriculture. In addition, the moderating effects of innovation resistance on these influence relationships were also verified. The limitations of this study are the lack of verification of perception changes and the inability to control variables. As a result of this research, the results of the UTAUT in other fields were confirmed in this study. It is hoped that this study will further facilitate the research of agriculture in ICT convergence technology.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.141-151
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• 2002

The success of sericulture industry in India is mainly attributed to the well-planned annual sericultural activity and the systematic implementation of pest preventive and control measures. The insect spectrum of silkworm and its food plants is complex and plays a major role in limiting the production of silk. Insects cause extensive damage to plant whereas predators and parasites either kill the silkworm larvae or force them to spin flimsy cocoons. Unilateral control measure against this pest is mainly based on the use of synthetic organic insecticides. Though these approaches initially paid rich dividends, the undesirable consequences soon surfaced. Insecticide induced resurgence of gall midges, leafhopper, leaf roller, secondary pest out breaks and development of pest biotypes has led to realization of Integrated Pest Management in sericulture. Various components of IPM, viz. Host plant resistance, cultural practices, biological control, chemical control and integrating them at various technological levels have been studied. Sources of host plant resistance have been identified for some of the major insect pests. High yielding mulberry variety has been propagated and their resistances towards major pests have been recorded. Cultural practices like pruning, pollarding, judicious use of nitrogen, optimum spacing and weed management have preyed to be the powerful tools in containing pests. Natural control over the pest population build- up exerted by the wide range of parasitoids, predators and pathogens has been well documented with identification of natural enemies and studies on their potential. Augmentation, through inoculation or inundative releases of parasitic arthropods, is the most direct way of increasing the numbers of these beneficials in sericulture.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.1
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• pp.91-98
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• 2010

The increasing of power and processing speed and miniaturization of central processor unit (CPU) used in electronics equipment requires better performing thermal management systems. A typical thermal management package consists of thermal interfaces, heat dissipaters, and external cooling systems. There have been a number of experimental techniques and procedures for estimating thermal conductivity of thin, compressible thermal interface material (TIM). The TIM performance is affected by many factors and thus TIM should be evaluated under specified application conditions. In compact packaging of electronic equipment the chip is interfaced with a thin heat spreader. As the package is made thinner, the coupling between heat flow through TIM and that in the heat spreader becomes stronger. Thus, a TIM characterization system for considering the heat spreader effect is proposed and demonstrated in detail in this paper. The TIM test apparatus developed based on ASTM D-5470 standard for thermal interface resistance measurement of high performance TIM, including the precise measurement of changes in in-situ materials thickness. Thermal impedances are measured and compared for different directions of heat dissipation. The measurement of the TIM under the practical conditions can thus be used as the thermal criteria for the TIM selection.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.136-142
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• 2008

Thermal management of a junction box of a passenger car has recently become more challenging due to its smaller size and larger current capacity. Thus, it is essential to perform the thermal optimization of a junction box in its design on an early stage of vehicle design. In this study, 3 dimensional CFD simulation with experimental measurement has been done to study for better thermal management of the junction box. First, the study of thermal characteristics of electric relays in the junction box has revealed that each surface of the relay has very different thermal resistance. In addition, an idea to install a cooling fan on the junction box has been studied and it was found that the forced cooling method was not effective on the system to keep the thermal resistance to the reasonable level of the junction box. Finally, the effect of external flows around the junction box on the temperatures of the relays, fuses, etc. has been studied and the result shows that the installation of the junction box at the proper place in an engine room can avoid any unnecessary overdesign in thermal management.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.69-86
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• 2020

Purpose: This study aims to determine the optimal conditions for the spot welding process that mechanically connects the case of a cylindrical secondary battery and the negative tab. Methods: We use 33 factorial design to derive the optimal conditions for the spot welding process. The pulling strength, the cross-sectional area of nugget, and the shock test life are selected as response variables, which can represent the resistance welding quality. The input variables are selected as the welding time, welding voltage, and pressure, which are the controllable factors in the spot welding process. Results: The main effects of welding time and welding voltage and the interaction effect of welding time and welding voltage are significant. Conclusion: The optimal conditions for the spot welding process to mechanically join the negative electrode tab of the cylindrical secondary battery and the battery case are developed. The result shows that the pulling strength is increased by 44% compared to before improvement under optimal conditions.

• Elastomers and Composites
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• v.56 no.1
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• pp.20-31
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• 2021

There is an increasing demand for the rolling resistance reduction in truck bus radial (TBR) tires in the tire industry. In TBR tires, natural rubber is used as a base polymer to prevent wear and satisfy required physical properties (cut and chip). A binary filler system (silica and carbon black) is used to balance the durability of the tire and rolling resistance performance. In this study, natural rubber (NR) compounds applied with a binary filler system were manufactured at different cure temperatures for vulcanizate structure analysis. The vulcanizate structures were categorized into carbon black bound rubber, silica silane rubber network, and chemical crosslink density by sulfur. Regardless of the cure temperature, the cross-link density per unit content of carbon black had a greater effect on the properties than silica due to affinity with NR. The relationship analysis between the mechanical, viscoelastic properties with vulcanizate structure could be a guideline for manufacturing practical TBR compounds.