• Transactions of Materials Processing
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• v.3 no.4
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• pp.401-414
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• 1994

Springback for the three point bending is anlayzed and experimented. Neutral axis is assumed to remain at the midthickness for large ratio of radius of curvature to thickness. Pure bending theory is used to be extended to the analysis of the springback for three point bending. The specimen is thought to be divided into numerous small elements. The theory for pure bending is then adopted for analysis of each element to obtain springback in terms of the relationship between initial and final deflections. the boundary conditions between neighborhood elements are the deflection and slope which should be the same. Deflection is calculated by summing up the deflections of each element. Experiments have been performed for different conditions which are punch radius, span length, and initial deflections. Comparisons between the analytical solution and experimental results show the same trends.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.245-253
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• 2020

Objective: To develop the fermentation quality and chemical composition of alfalfa (Medicago sativa Lam.) silage, plants were inoculated with different lactic acid bacteria (LAB) strains at field 24 hours before harvest. Methods: The treatment groups were as follow: silage without additive as a control and inoculated with each strains of Lactobacillus brevis (LS-55-2-2), Leuconostoc citerum (L. citerum; L-70-6-1), Lactobacillus bifermentans (L. bifermentans; LS-65-2-1), Lactobacillus plantarum (L. plantarum; LS-3-3) and L. plantarum (LS-72-2). All the silages were stored at 25℃. Parameters such as pH, microorganism and volatile fatty acid contents, crude protein, neutral detergent fiber, acid detergent fiber, net gas, metabolizable energy, organic matter digestibility, dry matter intake and relative feed value were measured to determine fermentation quality, chemical compositions and relative feed value of alfalfa silages. Results: Significant differences were found among the control and treated groups in terms of pH and microorganism contents at all opening times and crude protein, net gas, metabolizable energy and organic matter digestibility of final silage. The pH values ranged from 4.70 to 5.52 for all treatments and control silage had the highest value of overall treatments at T₇₅d silages. Volatile fatty acid of silages was not influenced significantly by inoculations. However, lactic acid content of L. bifermentans (LS-65-2-1) was higher than the other treatments. The highest metabolizable energy and organic matter digestibility were recorded from L. citerum (L-70-6-1) inoculation. In addition, no significant differences were found among treatments in terms of neutral detergent fiber, acid detergent fiber, dry matter intake and relative feed value. Conclusion: Among the treated LAB isolates, L. bifermentans came into prominence especially in terms of organic acid composition and quality characters of silages.

• Journal of Fashion Business
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• v.24 no.5
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• pp.52-71
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• 2020

This study examines the color characteristics of the usage of the color pink in menswear by analyzing its usage status and method. It involves an empirical research method establishing the frame of the study through a document study centered on trend, gender neutral considerations, and the utilization of the color pink in men's fashion, by analyzing the characteristics of color and tone by extracting the pink color shown in menswear collections as well as analyzing and categorizing the fashion image and genderless characteristics. Analyzing the color and tone of the pink color shown indicate that bright, light and pale tones had higher proportions. Pink color can also be said to be utilized as a design element that gives off a younger and more vital color image in menswear. Further, the use of brighter and softer pink colors can be interpreted as reflecting modern society's demands of masculinity to change into a more sophisticated and soft image. To analyze the characteristics of the color pink utilized in gender neutral fashion, fashion images were presented as the analysis standard. An image grouping technique was used to classify pink while utilizing genderless types-fashion style. The result showed that even with the same pink color, the fashion image can vary with different methods of expression in terms of clothes and styling. The results of this study can serve as basic data for planning fashion design concepts as it analyzed pink-using fashion images and the genderless concept type.

• Safety and Health at Work
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• v.5 no.1
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• pp.27-31
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• 2014

Background: Carpal tunnel syndrome (CTS) is a common work-related peripheral neuropathy. In addition to grip force and repetitive hand exertions, wrist posture (hyperextension and hyperflexion) may be a risk factor for CTS among workers. However, findings of studies evaluating the relationship between wrist posture and CTS are inconsistent. The purpose of this paper was to conduct a meta-analysis of existing studies to evaluate the evidence of the relationship between wrist posture at work and risk of CTS. Methods: PubMed and Google Scholar were searched to identify relevant studies published between 1980 and 2012. The following search terms were used: "work related", "carpal tunnel syndrome", "wrist posture", and "epidemiology". The studies defined wrist posture as the deviation of the wrist in extension or flexion from a neutral wrist posture. Relative risk (RR) of individual studies for postural risk was pooled to evaluate the overall risk of wrist posture on CTS. Results: Nine studies met the inclusion criteria. All were cross-sectional or case-control designs and relied on self-report or observer's estimates for wrist posture assessment. The pooled RR of work-related CTS increased with increasing hours of exposure to wrist deviation or extension/flexion [RR = 2.01; 95% confidence interval (CI): 1.646-2.43; p < 0.01: Shore-adjusted 95% CI: 1.32-2.97]. Conclusion: We found evidence that prolonged exposure to non-neutral wrist postures is associated with a twofold increased risk for CTS compared with low hours of exposure to non-neutral wrist postures. Workplace interventions to prevent CTS should incorporate training and engineering interventions that reduce sustained non-neutral wrist postures.

• Structural Engineering and Mechanics
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• v.57 no.5
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• pp.837-859
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• 2016

An efficient shear deformation theory is developed for wave propagation analysis of an infinite functionally graded plate in the presence of thermal environments. By dividing the transverse displacement into bending and shear parts, the number of unknowns and governing equations of the present theory is reduced, and hence, makes it simple to use. The thermal effects and temperature-dependent material properties are both taken into account. The temperature field is assumed to be a uniform distribution over the plate surface and varied in the thickness direction only. Material properties are assumed to be temperature-dependent, and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. The governing equations of the wave propagation in the functionally graded plate are derived by employing the Hamilton's principle and the physical neutral surface concept. There is no stretching.bending coupling effect in the neutral surface-based formulation, and consequently, the governing equations and boundary conditions of functionally graded plates based on neutral surface have the simple forms as those of isotropic plates. The analytic dispersion relation of the functionally graded plate is obtained by solving an eigenvalue problem. The effects of the volume fraction distributions and temperature on wave propagation of functionally graded plate are discussed in detail. It can be concluded that the present theory is not only accurate but also simple in predicting the wave propagation characteristics in the functionally graded plate. The results carried out can be used in the ultrasonic inspection techniques and structural health monitoring.

• Journal of the Korean Electrochemical Society
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• v.26 no.4
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• pp.56-63
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• 2023

The development of renewable energy technologies, such as solar, wave, and wind power, has led to the diversification of water electrolysis technologies, which can be easily coupled with renewable energy sources in terms of economics and scale. Water electrolysis technologies can be classified into three types based on operating temperature: low-temperature (<100 ℃), medium-temperature (300-700 ℃), and high-temperature (>700 ℃). It can also be classified by the type of electrolyte membrane used in the system. However, the concepts of thermodynamic and thermo-neutral voltages calculations and are very important factors in the evaluation of energy consumption and efficiency of water electrolysis technologies, are often confused. This review aims to contribute to a better understanding of the calculation of operating voltage and efficiency of PEM water electrolysis technologies and to clarify the differences between thermodynamic voltage and thermo-neutral voltage.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.403-412
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• 1992

This note examines a situation where a risk-neutral insurer and a risk-averse individual (prospective insured) negotiate to reach an arbitration point of the price of insurance over the terms of an insurance contract in order to maximize their respective self-interests. The situation is modeled as a Nash bargaining problem. We analyze the dependence of the price of insurance, which is determined by the Nash solution, on the parameters such as the size of insured loss, the probability of a loss, the degree of risk-aversion of the insured, and the riskiness of loss distribution.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.156-159
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• 2002

2차원 감성 모형에서는 중립 감성이라는 것이 존재하지 않지만, 인간이 생활에서 느끼는 감성은 중립 감성이 상당 부분을 자치한다. 따라서 인간의 감성 변화를 정확히 파악하기 위해서는 중립 감성에 대한 이해가 필수적이다. 본 연구에서는 5명의 뇌파 출현량을 반복적으로 측정함으로써 중립 감성의 개인내 안정성과 개인간 차이를 살펴보았다. 그 결과 $\theta$파와 $\alpha$파는 개인내 안정성을 반영하였으며, $\delta$파와 $\beta$파는 개인간 차이를 반영하는 것으로 나타났다.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1157-1165
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• 2014

The T-type topology is a three-level topology that has an advantage in terms of its number of switching device and its efficiency when compared to the neutral-point clamped (NPC)-type topology. With the recent increase in the usage of the T-type topology, the interest in its reliability has also increased. Therefore, a tolerance control for a T-type rectifier is necessary to improve the reliability of applications when an open-switch fault occurs. NPC-type rectifiers cannot eliminate input current distortion completely. However, the T-type rectifier is able to restore distorted current. In this paper, a tolerance control for the $S_{x2}$ and $S_{x3}$ open-switch faults of a T-type rectifier is proposed where it is advantageous in terms of efficiency when compared with other tolerance controls. The performance of the proposed tolerance control is verified through simulation and experimental results.

• Journal of the Korea Concrete Institute
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• v.29 no.2
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• pp.179-187
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• 2017

The design provisions for the maximum steel ratio in reinforced concrete flexural members is normally provided to ensure sufficient ductility and economy by steel yielding at member failure. In the Concrete Structural Design Code (2012), the maximum steel ratio is expressed in terms of a net strain in tensile steel, and leading to very high steel ratio in the case of using high strength materials. Thereby, this may result in difficulty to satisfy a required workability at concrete placing. On the contrary, in the Korean Highway Bridge Design Code (Limit State Design) the maximum steel ratio is given in terms of the maximum neutral axis depth ratio that is 0.4. From these results, a rational model for the maximum steel ratio is suggested so as to satisfy a ductility as well as a workability.