• Journal of Advanced Marine Engineering and Technology
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• v.5 no.1
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• pp.12-19
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• 1981

As the fuel oil cost covers from 45% to 60% of the total expenditure for fishing boat operation, the energy saving is now an urgent problem to be taken a countermeasure for engineers, manufacturers or specialists engaging in this field. Undertaking a second-hand engine of the trainging ship, the author made several reconstructions to restore its performances. By inserting foot linears of connecting rods the compression ratio was increased and by adjusting both the fuel injection timing and the cooling water outlet temperature, its thermal efficiency was improved. The results of the experimental operation were summarized as follows. 1. By raising the piston top position 0.75mm more than the value of the operating manual, the compression pressure increased 1.3 kg/$cm^2$ and the maximum pressure did 3.4 kg/$cm^2$ at 75% load. 2. At 75% load, the difference of the maximum pressure between each cylinder was decreased from 2.4 kg/$cm^2$ to 1.8 kg/$cm^2$. 3. The fuel consumption was decreased about 8 g/ps.h at 75% load, and about 5.3 g/ps.h at 85% load. 4. The brake thermal efficiency was improved about 1.5% at 75% load and 0.9% at 85% load.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.561-568
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• 1994

A man model can be used as an effective tool to design ergonomically sound products and workplaces, and subsequently evaluate them properly. For a man model to be truly useful, it must be integrated with a posture prediction model which should be capable of representing the human arm reach posture in the context of equipments and workspaces. Since the human movement possesses redundant degrees of freedom, accurate representation or prediction of human movement was known to be a difficult problem. To solve this redundancy problem, a psychophysical cost function was suggested in this study which defines a cost value for each joint movement angle. The psychophysical cost function developed integrates the psychophysical discomfort of joints and the joint range availability concept which has been used for redundant arm manipulation in robotics to predict the arm reach posture. To properly predict an arm reach posture, an arm reach posture prediction model was then developed in which a posture configuration that provides the minimum total cost is chosen. The predictivity of the psychophysical cost function was compared with that of the biomechanical cost function which is based on the minimization of joint torque. Here, the human body is regarded as a two-dimensional multi-link system which consists of four links ; trunk, upper arm, lower arm and hand. Real reach postures were photographed from the subjects and were compared to the postures predicted by the model. Results showed that the postures predicted by the psychophysical cost function closely simulated human reach postures and the predictivity was more accurate than that by the biomechanical cost function.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.255-266
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• 2017

In this study, self-supporting roofing elements especially convenient for large-span structures such as stadium, airport terminal, mall, coliseum, etc. were examined with respect to critical buckling load. These elements were assumed as laminated composite plates and, variation of free-edge forms, cutout types and lamination configurations were used as design parameters. Based on the architectural feature and structural requirements, the effects of curvilinear free-edge form on critical buckling load were focused on in this research. Within this scope, 14 types of lamination configuration were specified according to various orientation angle, number and thickness of plies with a constant value of total plate thickness. Besides that, 6 different types of cutout and 3 different free-edge forms were determined. By combining all these parameters 294 different critical buckling load analyses were performed by using ANSYS Mechanical software based on finite element method. Effects of those parameters on critical buckling load were evaluated referring to the obtained results. According to the results presented here, it may be concluded that lamination conditions have more significant influence on the critical buckling load values than the other parameters. On the other hand, it is perceived that curvilinear free-edge forms explicitly undergo changings depending on lamination conditions. For future work, existence of delamination might be considered and progression of the defect could be investigated by using non-linear analysis.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.3
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• pp.287-297
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• 1994

The purpose of this study is to investigate the Improvement of fiber surface, tenacity & elogation, fabric counts, thickness, handle, moisture regain, static voltage, handle, dyeability when polyester fabrics are treated with NaOH solution adding quartemary ammonium salt (Benzyl dimetyl dodecyl ammonium chloride . BDMDAC) The results are as follows. I. In regard to the method of processing VET, when the PET fabrics are alkaline-hydrolyzed adding BDMDAC, the weight loss of PET fabrics increased remarkably to the increse of BDMDAC concentration than when they are treated only in NaOH solution. When PET fabrics are alkaline-hydrolyzed the amount of BDMDAC as the catalyst is proper lg/1 II. The change in physical & chemical properties of alkaline-hydrolyzed PET fabrirs. 1. As the amount of the weight loss on PET fabrics increased, the void space of the PET yale increased but tenacity & elongation and thickness decreased. 2. The fabric counts of PET increased due to shrinkage by alkaline-hydrolydzing. 3. As the amount of of the weight loss on PET fabrics increased. NUMERI, FUKURAMI, increaseed and KOSHI decreased and Total hand value(T.H.V) in all cases increaseed. When the weight Ioss is 30.9% T.H.V. is best. 4. Moisture regain of PET fabrics a little increased by alkaline-hydrolyzing treatment. As the weight loss increased, static voltage is decreased. 5. The last dye absorption is different according to the degree of the Affinity. In regard to the difference of dye color, the dyestuff of low molecular weight dyed for deep color.

• Journal of Veterinary Clinics
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• v.5 no.1
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• pp.23-30
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• 1988

A total of 127 foremilk samples from dairy farms in Chonnam district was examined for the subclinical mastitis eve. six months, using a method of the N-acetyl-${\beta}$ -D-glucosaminidase (NAGase) test in relation to the California mastitis test(CMT) and the somatic tell count(SCC) and the compatibility and efficiency rating between the NAGase test and the other screening test were conducted. Fifteen subclinically mastitic cows were treated with a single oral dose of 7.5mg/kg of levamisole hydrochloride. The results are summarized as follows. 1. A linear relationship was found among the NAGase level, the CMT score and the SCC level, and it was found that NAGase activity measurements were comparable with other screening tests for diagnosing cows with mastitis. 2. Compatibilites between the NAGase and the CMT were 96.1%, and that of the NAGase and SCC were 93.7%. On the other hand, relative efficiency ratings of Postle's equation between the NAGase and CMT were 89.4%, and that of the NAGase and SCC were 84.1%. 3. Considering the result of CMT, SCC and NAGase level after treatment with levamisole hydrochloride it seemed to be of special value in the treatment of bovine subclinical mastitis.

• Tunnel and Underground Space
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• v.9 no.1
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• pp.12-19
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• 1999

In this study, ground vibrations of a surface blasting for golf links and a tunnel blasting for highway construction were measured to investigate the effect of blasting conditions such as total charge and distance from blasting point. In surface blasting, site factor K and n were 74.1 and -1.37, respectively, which were analyzed by means of cube root scaled distance. The more were measuring distance, the higher were absolute value of K and n. Principal frequency was in range of 5~60 Hz in surface blasting, where that of 80 percent was in range of 10~30 Hz. On the other hand it was in range of 25~98 Hz in tunnel blasting, which showed higher than of surface blasting.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.1
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• pp.134-142
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• 2003

Performances of Taekwondo fabrics were evaluated in respect of fiber component. yarn count, weave structure and wearing comfort. As a beginning step, we investigated the present situation of Taekwondo wears by questionnaire from pro and amateur Taekwondo players. Samples employed in this study were cotton/nylon blend fabric that was newly woven for this study as well as fabrics of current Taekwondo wears for sale in the market. Their fundamental properties measured were such as air permeability, water vapor transport. wickability, absorption rate, Qmax values, thermal conductivity, durability, hand value, and etc. In addition, subjective wearing sensations were evaluated using Taekwondo wears made of those fabrics. From the results of the objective measurement and the subjective wearing test, we estimated the total fitness of fabrics as a Taekwondo wear. From the questionnaire we could see that pro players and amateurs wanted highly absorbing, quick drying, and soft-tough and complained abrasive surfaces and static elasticity of current fabrics. In view of the results so far achieved, nylon blended fabrics newly woven in this study, showed better comfort-related properties from both of the objective and subjective tests. It was also represented that finer yams enhanced water absorption and touch, and fabrics with rough surface such as honeycomb weave was superior in wearing comfort as well as aesthetic appearance.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.5
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• pp.103-112
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• 2011

Old big tree transcends the simple meaning of trees as they are the natural monuments that embody the people's history and culture of this land. The Cultural Heritage Administration of Korea(CHA) defines and protects old big tree based not only on the size of the tree but also on its definitive cultural and natural factors such as value, implications, and originality. This research aims to identify and analyze the growth conditions, soil conditions and location character of 20 old big tree in Gyeongsangnamdo korea. The research examined the soundness of the arboreal form, the degree of damage on the bark, as well as the quantity of leafs levels to evaluate the overall condition of growth and development. Also, 9 elements such as soil texture, nitrogen and organic matter content, soil pH, phosphoric acid and EC were further analyzed The research analyzed in correlation of Growth condition and soil. Tree health related positivity that total nitrogen and organic matter. The result which analyzes location character, With natural monument old big trees raising a hand the area where is contiguous appeared with the fact that the farming village style where the rice field and the arable land of field etc. This research aimed at generating some foundational reference data for the analysis of the habitation and management conditions of natural monument old big tree within the Gyeongsangnamdo korea.

• Journal of the Korean Society of Food Culture
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• v.31 no.5
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• pp.411-429
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• 2016

This study introduced "Dongchundang Eumsikbeop" and examined its value as a reference. "Dongchundang Eumsikbeop" is a recipe book from the Head House of Eunjin Song Clan. As the author is unknown, the book is named after where it was found. "Dongchundang Eumsikbeop" records the recipes for 32 total foods, including 12 types of fermented foods, eight types of liquor, and six types of side dishes, etc. In "Jusiksiui", written by the same clan 100 years before, fermented foods account for 15% of its contents. On the other hand, this book assigns 34% of its space to fermented foods. It is assumed that the recipe book must have been compiled according to what households ate the most, as hostesses had to cook for their households due to financial difficulties at the time. In "Dongchundang Eumsikbeop", baking soda and alum were used as leavening agents for confectionery while sugar-based caramelizing was used for making soy sources, implying that modern food techniques were already applied. In short, this book provides a glimpse into the wisdom of hostesses of the Head House who improved recipes to suit changing times while adhering to tradition.

• Journal of Biomedical Engineering Research
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• v.34 no.1
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• pp.1-7
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• 2013

According to the frequent use of mobile devices, risk of repetitive strain injury for the finger joints was increasing recently. The purpose of this study was to investigate the difference of muscular endurance limit of the thumb between adults and children. A total of thirty subjects (15 adults: $41.0{\pm}7.9$ years and 15 children: $9.5{\pm}2.7$ years) was recruited for this experiment. Maximum voluntary contraction (MVC) of the thumb was measured for 100 trials for each subject by using a push-pull gauge. From the maximum peak value obtained, three main factors (MVC, endurance limit, and fatigue index) were defined to quantify fatigue characteristics of the thumb flexor muscle. The experimental results showed that the mean of MVC, endurance limit, and fatigue index of the children were approximately 50% compared to the adults (p < 0.001). From the results of Pearson correlation test, the endurance limit was highly correlated with weight, age, hand length rather than height. Based on this study, children are more vulnerable to repetitive task using the thumb such as text/SNS messaging, gaming, and scrolling.