• Fashion & Textile Research Journal
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• v.18 no.3
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• pp.338-350
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• 2016

The purpose of this study is to analyze joint angle for a range of swing motion derived through 3D motion analysis in order to design the ergonomic golf wear, use it for evaluation method of apparel fit to improve exercise functionality and provide the basic materials necessary for designing clothes. In order to do this, the subjects for this study were 3 men of age 20s. The data for a range of motion of golf swing were collected by using equipment for 3D motion analysis and then were used for analysis of joint angles and evaluation method of apparel fit. Range of motion was derived through 3D motion analysis of golf swing motion and joint angles for items of joint motion item and of X, Y, and Z-axis were calculated, respectively. In order to set the evaluation questions for evaluation of apparel fit, to find a range of motion at the maximal value and the minimal value of swing motion. As a result, during the swinging motion, neck extension, right shoulder extension, right/left elbow extension, right/left elbow supination did not appear. Items of joint motion showing the maximum at range of each swing motion were applied into 55 questions and consisted. The results of this study were meaningful as a basic study to apply 3D motion analysis to the fashion industry. It's expected to be used to design functional clothing.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.145-152
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• 2019

All machines deteriorate in performance over time. The phenomenon that causes such performance degradation is called deterioration. Due to the deterioration, the process mean of the machine shifts, process variance increases due to the expansion of separate interval, and the failure rate of the machine increases. The maintenance model is a matter of determining the timing of preventive maintenance that minimizes the total cost per wear between the relation to the increasing production cost and the decreasing maintenance cost. The essential requirement of this model is that the preventive maintenance cost is less than the failure maintenance cost. In the process mean shift model, determining the resetting timing due to increasing production costs is the same as the maintenance model. In determining the timing of machine adjustments, there are two differences between the models. First, the process mean shift model excludes failure from the model. This model is limited to the period during the operation of the machine. Second, in the maintenance model, the production cost is set as a general function of the operating time. But in the process mean shift model, the production cost is set as a probability functions associated with the product. In the production system, the maintenance cost of the equipment and the production cost due to the non-confirming items and the quality loss cost are always occurring simultaneously. So it is reasonable that the failure and process mean shift should be dealt with at the same time in determining the maintenance time. This study proposes a model that integrates both of them. In order to reflect the actual production system more accurately, this integrated model includes the items of process variance function and the loss function according to wear level.

• Journal of Surface Science and Engineering
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• v.38 no.3
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• pp.126-135
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• 2005

SKD 11 steel has been widely used for tools, metallic mold and die for press working because of its favorable mechanical properties such as high toughness and creep strength as well as excellent oxidation resistance. The ion nitrided tool steel containing Mo results in improvement of corrosion resistance, strength at high temperature and pitting resistance, especially in $Cl^-$ contained environment. But the Mo addition causes a disadvantage such as lower oxidation resistance at elevated temperature. In this study, several effects of ion-disadvantage on the oxidation characteristics for SKD 11 steel with various oxidation temperature were investigated. SKD 11 steels were manufactured by using vacuum furnace and solutionized for 1 hr at $1,050^{\circ}C$. Steel surface was ion nitrided at $500^{\circ}C$ for 1 hr and 5 hr by ion nitriding equipment. ion nitrided specimen were investigated by SEM, OM and hardness tester. Oxidation was carried out by using muffle furnace in air at $500^{\circ}C,\;700^{\circ}C\;and\;900^{\circ}C$ for 1hr, respectively. Oxidation behavior of the ion nitrided specimen was investigated by SEM, EDX and surface roughness tester. The conclusions of this study are as follows: It was found that plasma nitriding for 5 hr at $500^{\circ}C$, compared with ion nitriding for 1 hr at $500^{\circ}C$, had a thick nitrided layer and produced a layer with good wear, corrosion resistance and hardness as nitriding time increased. Nitrided SKD 11 alloy for 1hr showed that wear resistance and hardness decreased, whereas surface roughness increased, compared with nitrided SKD 11 alloy for 5 hr. The oxidation surface at $900^{\circ}C$ showed a good corrosion resistance.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.216-224
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• 2024

This paper presents a method for analyzing the reliability of hardware electronic equipment, taking into account failures caused by radiation. Traditional reliability analysis primarily focuses on the wear out failure rate and often neglects the impact of radiation failure rates. We calculate the wear out failure rate through physics of failure analysis, while the radiation failure rate is semi-empirically estimated using the Verilog Fault Injection tool. Our approach aims to ensure reliability early in the development process, potentially reducing development time and costs by identifying circuit vulnerabilities in advance. As an illustrative example, we conducted a reliability analysis on the ISCAS85 circuit. Our results demonstrate the effectiveness of our method compared to traditional reliability analysis tools. This thorough analysis is crucial for ensuring the reliability of FPGAs in environments with high radiation exposure, such as in aviation and space applications.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.71-78
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• 2020

The purpose of this study is to investigate the effect of wearing clothes, Level B, and Level C PPE on normal CPR using mannequins. The paramedics who participated in this experiment were 20 paramedics with more than 5 years of experience in firefighting area C. It was found that chest compressions in the process that hand off time was 11.9 seconds in the uniform wearing group, 11.4 seconds in the level C PPE wearing group, and 13.1 seconds in the SCBA wearing group. In other words, wearing personal protective equipment prevents the movement of paramedics and uses compensatory movements, which may increase the difficulty of efficient first aid. If this situation persists, it may cause fatigue and damage to the body of paramedics. Rescue and paramedics should wear level personal protective equipment in case of emergencies and conduct rescue and CPR training.

• The Journal of the Convergence on Culture Technology
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• v.3 no.2
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• pp.15-20
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• 2017

We are investigated about the Hepatitis infection risk of the funeral director related to wearing PPE(Personal Protect Equipment) within Metropolitan, Chungcheong and Gyeongsang regions in Korea. We are classified that the vaccinated group was classified as low risk group and the non-vaccinated group was classified as high risk group. And we are analyzed the risk rate of infection based on whether or not to wear PPE(personal protective equipment) among high-risk groups. The result is as follows. The mask wearing rate of high-risk group about HAV(hepatitis A virus) is three times lower than that of low-risk group. The surgical glove wearing rate of high-risk group about HBV(hepatitis B virus) is twice lower than that of low-risk group. The surgical glove and mask not wearing rate among the high-risk group observe that potential infection risk was high 4.23 times and 3.5 times, respectively. We are concluded that increasing the risk of potential infection risks from the funeral director could result in increased risk of infection to national public health, including the bereaved family. We are suggested that the funeral director must be bound to vaccinate against hepatitis and make PPE mandatory. It is deemed necessary for the government to develop policies to promote personal health and national health care.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.1
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• pp.125-147
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• 2011

Recently, with a high demand for the construction and remodeling of libraries, and the rapid increase in the number of libraries during the last two years, the concern and need for library goods is also increasing sharply. The purpose of this study is to develop a new classification scheme of library goods by clarifying the terminology which could provide an accurate information on library goods and allow for their smooth circulation. In this study, library goods are defined as all kinds of products required for effectively collecting, organizing and providing services with library materials, and classified into library equipments and library supplies. The term, library equipment is principally used for those things that do not wear out within a certain time period, such as furniture and machinery. Library supplies refer to those things that are expendable. As the terminology is clarified, the classification scheme can be further refined. Library equipment, for example, can be classified as furniture, library system solutions, and computers and multi-media tools. Library supplies can be classified into library organization and repair supplies, sign systems, and miscellaneous articles. Finally, six major categories which include 117 different items are presented.

• Corrosion Science and Technology
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• v.13 no.1
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• pp.28-35
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• 2014

Recently, the fuel oil of diesel engines of marine ships has been increasingly changed to heavy oil of low quality as the oil price is getting higher and higher. Therefore, the spiral gear attached at the motor of the oil purifier which plays an important role to purify the heavy oil is also easy to expose at severe environmental condition due to the purification of the heavy oil in higher temperature. Thus, the material of the spiral gear requires a better mechanical strength, wear and corrosion resistance. In this study, the heat treatment(tempering) with various holding time at temperature of $500^{\circ}C$ was carried out to the alloy of Cu-7Al-2.5Si as centrifugal casting, and the properties of both hardness and corrosion resistance with and without heat treatment were investigated with observation of the microstructure and with electrochemical methods, such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram, and a.c. impedance. in natural seawater solution. The ${\alpha}$, ${\beta}^{\prime}$ and ${\gamma}_2$ phases were observed in the material in spite of no heat treatment due to quenching effect of a spin mold. However, their phases, that is, ${\beta}^{\prime}$ and ${\gamma}_2$ phases decreased gradually with increasing the holding time at a constant temperature of $500^{\circ}C$. The hardness more or less decreased with heat treatment, however its corrosion resistance was improved with the heat treatment. Furthermore, the longer holding time, the better corrosion resistance. In addition, when the holding time was 48hrs, its corrosion current density showed the lowest value. The pattern of corroded surface was nearly similar to that of the pitting corrosion, and this morphology was greatly observed in the case of no heat treatment. It is considered that ${\gamma}_2$ phase at the grain boundary was corroded preferentially as an anode. However, the pattern of general corrosion exhibited increasingly due to decreasing the ${\gamma}_2$ phase with heat treatment. Consequently, it is suggested that the corrosion resistance of Cu-7Al-2.5Si alloy can be improved with the heat treatment as a holding time for 48 hrs at $500^{\circ}C$.

• Clean Technology
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• v.27 no.4
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• pp.297-305
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• 2021

In the domestic aluminum industry, the extrusion process is a major process accounting for more than 40% of the total production. However, most domestic aluminum extrusion companies produce aluminum using old equipment that is more than 30 years old. Extrusion press is when the equipment is not replaced before the wear and breakage of major parts occur, reducing productivity and increasing the defect rate compared to new equipment. The old extrusion press often loses part drawings, so it is difficult to repair them properly on-site and to remanufacture them due to the lack of technical skills for maintenance. Therefore, a systematic remanufacturing plan must be designed from dismantling the equipment. In this study, remanufacturing FMEA was devised to remanufacture old extrusion press. The risk priority was analyzed by considering the degree of damage to the recycled parts, the cycle due to breakage/damage during the extrusion process, and the value of recycling resources due to remanufacturing. To standardize the remanufacturing process, remanufactured FMEA was performed through part analysis according to the structural analysis of the extrusion press. In addition, remanufacturing priorities were selected for each part, while remanufacturing itself was studied for efficiency of resource circulation and product quality stabilization.

• Corrosion Science and Technology
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• v.14 no.2
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• pp.54-58
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• 2015

A heavy oil of low quality has been mainly used in the diesel engine of the merchant ship as the oil price has been significantly jumped for several years. Thus, a combustion chamber of the engine has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas of the combustion chamber has been getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of the engine parts such as exhaust valve, piston crown and cylinder head surrounded with combustion chamber are more serious compared to the other parts of the engine. Therefore, an optimum repair welding for these engine parts is very important to prolong their lifetime in a economical point of view. In this study, 1.25Cr-0.5Mo filler metal was welded with SMAW method in the forged steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected and base metal zones were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% $H_2SO_4$ solution. The weld metal and base metal zones exhibited the highest and lowest values of hardness respectively. And, the corrosion resistance of the heat affected and weld metal zones was also increased than that of the base metal zone. Furthermore, it appeared that the corrosive products with red color and local corrosion like as a pitting corrosion were more frequently observed on the surface of the base metal zone compared to the heat affected and weld metal zones. Consequently, it is suggested that the mechanical and corrosion characteristics of the piston crown can be predominantly improved by repair welding method using the 1.25Cr-0.5Mo electrode.