• Journal of the Korean Geotechnical Society
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• v.31 no.10
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• pp.5-16
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• 2015

Considering the conversion of the Korea Construction Standards to Limit State Design (LSD), we analyzed the resistance bias factor for pullout resistance, as a part of the development of the Load and Resistance Factor Design (LRFD) for soil nailing; very few studies have been conducted on soil nailing. In order to reflect the local characteristics of soil nailing, such as the design and construction level, we collected statistics on pullout tests conducted on slopes and excavation construction sites around the country. In this study a database was built based on the geotechnical properties, soil nailing specifications, and pullout test results. The resistance bias factors are calculated to determine the resistance factor of the pullout resistance for gravity and pressurized grouting method, which are the most commonly used methods in Korea; moreover, we have relatively sufficient data on these methods. We found the resistance bias factors to be 1.144 and 1.325, which are relatively conservative values for predicting the actual ultimate pullout resistance. It showed that our designs are safer than those found in a research case in the United States (NCHRP Report); however, there was an uncertainty, $COV_R$, of 0.27-0.43 in the pullout resistance, which is relatively high. In addition, the pressurized grouting method has a greater margin of safety than the gravity grouting method, and the actual ultimate pullout resistance determined using the pressurized grouting method has low uncertainty.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.2
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• pp.329-338
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• 2011

The purpose of this study is to examine the effect of stabilization, resistance exercise, and combined exercise for lumbar on balance and walking ability of elderly. This study selected 22 subjects of over 65 years old elderly women who satisfy the study condition from A, B and C Senior Citizen's Center, in Daegu. The subjects were divided into groups; 7 for resistance exercise group, 8 for stabilization exercise group, and 7 for combined exercise group(resistance and stabilization exercise). The exercises were conducted for 60min a day, three times a week for 12 weeks. Balance and walking ability were checked before the exercise, 6 weeks later, and 12 weeks later. First, all lumbar muscle strengthening exercises were effective for static balance which changed according to exercising period. In dynamic balance, the resistance exercise group showed significant improvement in sit to stand. Stabilization exercise group showed significant improvement in all factors. The combined exercise group showed significant improvement in sit to stand and timed up and go. There was no difference between the exercise types. Second, the resistance exercise group showed significant change in Cadence which changed according to exercising period. The combined exercise group showed significant improvement in all factors. Between the exercise types, combined exercise was a bit more effective than resistance exercise. According to the result of 12 weeks of lumbar muscle exercise, combined exercise is considered to be the most effective exercise to prevent fall as it helps balance and walking ability slightly more than other exercises. Therefore, this study can understand the risk factors for fall accidents that frequently occur among elderly and adopt the combined exercise to prevent fall which in turn will prevent secondary problems occur from fall accidents and improve quality of life of elderly.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.405-416
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• 2019

Weeds are a serious problem in crop production. Use of synthetic herbicides is rapidly increasing in weed management worldwide including Korea. Herbicide application reduces the time spent on weed control. However, the evolution of resistance to herbicides in weeds has become widespread as a natural response to selection pressure imposed by agricultural management activities. If an herbicide with the same mechanisms of action is used repeatedly and intensively, it can rapidly select for a weed biotype that shifts toward difficult-to-control becoming a more tolerant weed and lead to the evolution of herbicideresistant weeds. Moreover, agricultural and biological factors have an important role in the development of herbicide-resistant weed populations. Mitigating the evolution of herbicide resistance in weeds relies on reducing selection through the diversification of weed control techniques. The resistance management of weeds in the future will strongly depend on intensive cropping systems. The current situation of intensive cropping systems with their heavy reliance on the efficacy of chemical weed control will not lead to significant containment of this problem. Therefore, management strategies need to overcome the further spread of herbicide resistance in weeds in Korean crop production. This review presents the current information on herbicide resistance in Korea and factors controlling the development of herbicide resistant weeds.

• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.269-275
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• 2004

Factorial design method is applied to investigate the effects of various factors simultaneously rather than to conduct a series of single-factor experiment. As the results, frost resistance of the concrete specimens, in both W/C ratio of 0.28 and 0.35, was highly affected by the type of coarse aggregate that is, andesite produced more durable concrete than the limestone. Durability factor of the specimens, with W/C ratio of 0.28, which were demolded after I day and transferred to the curing room was higher than those demolded after 2 days. This stated the efficiency of the high early curing in high strength concrete.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.57
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• pp.243-282
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• 2013

This study aims to develop the research model about the factors that have impact on uTradeHub users' acceptance and resistance to innovation. The followings show the research hypotheses and the results of test. i) The result of H1 empirical analysis confirmed that relative advantage and task adaptedness of e-Trade have more impact on acceptance of innovation than on resistance to it. And also perceived risk and complicity of e-Trade have more impact on resistance of innovation than on acceptance to it. ii) The result of H2 analysis confirmed that the characteristics of foreign trading companies (support by CEO and IT infra maturity) has more impact on acceptance of innovation than on resistance to it. iii) The result of H3 analysis confirmed that characteristics of uTradeHub user' resistance has more impact on resistance of innovation than on acceptance to it. And also, it was confirmed that acceptance of innovation has more impact on the diffusion of e-Trade than resistance to innovation. iv) The result of H4 analysis confirmed that the difference of the degree and factors that has impact on the user's resistance and acceptance by adoption stage of e-Trade. This study has significance in that it arranges the concept and stages of e-Trade systematically and, unlike other studies, it goes beyond the acceptance and diffusion of e-Trade to the inclusion of resistance together in the model.

• Tribology and Lubricants
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• v.35 no.1
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• pp.16-23
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• 2019

In this study, we aim to analyze the effects of both contact layer properties and surface roughness on contact resistance. The contact has a great influence on performance in terms of electrical conduction and heat transfer. The two biggest factors determining contact resistance are the presence of surface roughness and the surface layer. For this reason we calculated the contact resistance by considering both factors simultaneously. The model of this study to calculate contact resistance is as follows. First, the three representative surface parameters for the GW model are obtained by Nayak's random process. Then, the apparent contact area, real contact area, and contact number of asperities are calculated using the GW model with the surface parameters. The contact resistance of a single surface layer is calculated using Mikic's constriction equation. The total contact resistance is approximated by the parallel connection between the same asperity contact resistances. The results of this study are as follows. The appropriate thickness with reduction effect for contact resistance is determined according to the difference in conductivity between the base layer and surface layer. It was confirmed that the standard deviation of surface roughness has the greatest influence on surface roughness parameters. The results of this study will be useful for selecting the surface material and surface roughness when the design considering the contact resistance is needed.

• Bulletin of the Society of Naval Architects of Korea
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• v.9 no.1
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• pp.15-20
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• 1972

As the technique of resistance spot welding became more and more advanced the factors hitherto considered secondary become more and more important. Among these factors the distribution of heat and temperature during resistance spot welding is particularly important in conjunction with thermal stress, strain and residual stress, strain problems. The analytical investigations upon the transient temperature due to resistance spot welding were made for the carbon steel plate and aluminum alloy plate. The numerical values obtained by the analytical investigation are nearly identical with the temperature distribution which obtained by D.J. Sullivan and some other experimental data. It was thought therefore useful to estimate the heat effect upon the material such as a residual stress and strain, metalurgical change, change in physical properties and etc.

• The Journal of Information Systems
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• v.17 no.2
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• pp.73-94
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• 2008

Knowledge is a fundamental assets, therefore, the ability to create, acquire, integrate, and share knowledge has emerged as a fundamental organizational capability(Sambamurthy and Subramani, 2005). This apaper reports the results of an empirical study investigating the factors of acceptance and the moderating role of resistance in Knowledge Management Systems(KMS). The research model is based on the theory of planned behavior(TPB) and technology acceptance model(TAM). It includes the perceived usefulness instead of attitude, subjective norm, perceived behavior control and intention of acceptance of KMS. Also, three external variables namely task-technology fit, organizational support, and perceived rewards are added. In the research model, all hypothrses of the baseline model and the moderating effects of resistance were found to be significant. The authors also of fred several implications based chi the findings.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.12 no.1
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• pp.45-53
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• 2006

Thermal insulation is used in a variety of applications to protect temperature sensitive products from thermal damage. Several factors affect the performance of insulation packages. Among these factors, the thermal resistance of the insulating wall is the most important factor to determine the performance of the insulating package. In many cases, insulating wall consists of multi-layered structure and the heat transfer through this structure is a very complex process. In this study, an one-dimensional mathematical model, which includes all of the heat transfer principles covering conduction, convection and radiation in multi-layered structure, were developed. Based on this model, several heat transfer phenomena occurred in the air space between the layer of the insulating wall were investigated. From the simulation results, it was observed that the heat transfer through the air space between the layer were dominated by conduction and radiation and the low emissivity of the surface of each solid layer of the wall can dramatically increase the thermal resistance of the wall. For practical use, an equation was derived for the calculation of the thermal resistance of a multi-layered wall.

• IE interfaces
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• v.10 no.2
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• pp.109-114
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• 1997

The tread pattern of tire is represented by a great number of design factors, such as groove breadth of circumference direction, breadth direction, rib breadth, block length, kerfs, tread breadth and tread radius, etc. It is not efficient in time and cost to analyze the rolling resistance for a great number of real tread pattern, because It requires lots of pattern forming handwork. In order to optimize tread pattern for rolling resistance, the experiment is planed and analyzed by Taguchi's robust design methods. We identified the important design factors for Rolling Resistance, determined the optimal condition and calculated prediction value which is related. Using the experiment data and the analyzed data, we developed the program which could predict Rolling Resistance. It is expected that time and cost may be reduced in designing and developing new tire tread pattern.