• Proceedings of the KSR Conference
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• 1998.05a
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• pp.401-407
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• 1998

Recently, as the railway vehicles become speedy and massive, the collision is being regarded as an important factor for the assessment of safety for passenger. And the study of collision is being in progress more actively in advanced nations. In this study, the collision analysis is performed by using non-linear dynamic finite element program PAM-CRASH. The carbody used in analysis is made of Aluminum AL6005A to realize lightweight, and designed and manufactured by DHI (Daewoo Heavy Industry) lately. For the accuracy of the result in the practical collision, the experiment of material properties has been performed. The result of the analysis shows the underframe of rolling stock is the most important part as a collision energy absorbing structure. Further study is needed for optimal design which enables the carbody shell structure to disperse absorbing energy adequately.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.17-25
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• 2021

In this study, the mechanical properties of railway-vehicle aluminum under frame was investigated based on the metal inert gas (MIG) welding conditions. An aluminum-alloy (6005A-T6) extruded material used in the lower panel of a railway vehicle was connected through MIG welding to determine the mechanical properties of MIG welds. Argon shielding gas and filler materials, such as ER5356 and ER4043, were used as consumable welding materials. For the welding conditions of the test specimen, welding frequencies of 2.5 and 4.5 Hz were applied using the SynchroPuls function, and the root faces were 1.0 and 1.5 mm. The mechanical properties of the MIG welds were determined through tensile, bending, and fatigue tests.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.135-143
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• 1999

This investigation evaluates effects of notch depth, fatigue precrack length and side groove in impact specimen for estimation of a valid K1d by instrumented Charpy impact test. Specimen material is 6005-T6. for notch depth 2.0mm and 2.5mm specimens or within about 2mm fatigue precrack length with notch depth 2.0mm and 2.5mm specimens or within about 2mm fatigue precrack length with notch depth 2.0mm , dynamic fracture toughness [$K_{1d,(1)}$] obtained by crack initiation load($P_m$) should be used. Dynamic fracture toughness of side grooved specimens are overestimated to that of standard impact specimen about 15 %-20%. It is confirmed that the formula of dynamic fracture toughness obtained by impact absorbed energy is inappropriate for ductile materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6001-6005
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• 2012

Although people want to learn guitar easily and happily, it is difficult to learn because many restriction comes from expense, student's efficiency and teacher/s skill. In this paper, the guitar teaching program has been developed for who is difficult to learn guitar fingering. The guitar teaching system with ATmega 128 was programed using visual studio MFC program. The guitar fingering U/I program was investigated for beginners easy to learn the code and playing with guitar.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.559-564
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• 2009

Aluminum extrude is increasing to vehicle body manufacture of a recent railroad vehicle. Conventional welding of this aluminum extrude has been used MIG welding or resistance spot welding mainly. But the advanced manufactures like Japan's tried to apply the friction stir welding and friction spot joining at railroad vehicle body manufacture process. Therefore in this paper we tried to study to apply friction stir welding to AL 6005-T6 extrude which has been manufactured the railroad vehicle mainly. In this study we investigated first the mechanisms to affect the welding strength in friction stir welding. After we made the 3 tools of different shape, we observed how the welding strength changed while changing the welding time and the rotation speed, the plunging depth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.1-7
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• 2021

In this study, MIG welding was performed on extruded 6005A-T6 material, which is used in the base panel of railway vehicles. The material was considered as the experimental base material, and argon shielding gas and ER5356 and ER4043 filler metals were used as the consumable welding materials. Welding coupons were prepared under various welding conditions by using an auto-welding system that various welding conditions applied 2.5Hz and 4.5Hz the pulse frequency of SynchroPuls function of welding machine and 1.0mm and 1.5mm of root face affect the weld penetration of welding joint. The welding current and voltage were also varied for this testing. On the basis of the results obtained, optimum welding conditions are proposed.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6001-6005
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• 2013

Our aim was to explore anti-cell proliferative and anti-angiogenic potential of andrographolide by analyzing the expression pattern of cell proliferative (PCNA, Cyclin D1) and angiogenic (VEGF) markers during 7, 12-dimethylbenz(a)anthracene (DMBA) induced hamster buccal pouch carcinogenesis. DMBA painting three times a week for 14 weeks in the buccal pouch of golden Syrian hamsters resulted in oral tumors which were histopathologically diagnosed as well differentiated squamous cell carcinoma. Immunohistochemical (PCNA, VEGF) and RT-PCR (Cyclin D1) studies revealed over expression of PCNA, VEGF and Cyclin D1 in the buccal mucosa of hamsters treated with DMBA alone. Oral administration of andrographolide at a dose of 50 mg/kg bw to hamsters treated with DMBA not only suppressed the histological abnormalities but also down regulated the expression of PCNA, VEGF and Cyclin D1. The results of the present study suggest that andrographolide suppressed tumor formation in the buccal mucosa of hamsters treated with DMBA through its anti-cell proliferative and anti-angiogenic potential.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.672-676
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• 2006

The aim of this study is to evaluate the antioxidant, antimicrobial, and antitumor activities of various concentrations of partially purified substance(s) from green tea seed (Camellia sinensis L.). The total polyphenol contents of each fraction (non-adsorption fraction: F-1, fraction eluted with 40% methanol: F-2, and fraction eluted with 100% methanol: F-3) purified by Diaion HP-20 column chromatography were, in the increasing order: F-1 (3.7 mg tannic acid equivalents, TAB/g) < F-3 (23.2 mg TAB/g) < seed extracts (26.2 mg TAB/g) < F-2 (42.7 mg TAB/g). The scavenging activities toward the 1,1-diphenyl-2-picyrylhydrazyl (DPPH) radical were, in decreasing order: F-2 (93.3%) > butylated hydroxytoluene (BHT; 89.8%) > ascorbic acid (89.3%) > leaf extracts (70.3%) > F-3 (15.9%) > seed extracts (15.8%) > F-1 (14.8%) at a 0.1% concentration. In studies on antimicrobial activities, the results indicate that the growth of yeast (Candida albicans KCCM 11282 and Cryptococcus neoformans KCCM 50544) was inhibited more so than that of other fungi (Alternaria alternate KCTC 6005 and Rhizoctonia solani). In addition, it appears that the antitumor activities of the F-1, F-2, and F-3 fractions at a concentration of $50\;{\mu}g/mL$ showed 6, 7, and 23% growth inhibition of the HEC-1B cell line, 14, 11, 82% inhibition of the HEP-2 cell line, and 8, 16, and 81% inhibition of the SK-OV-3 cell line, respectively. Overall these results indicate that the antioxidant activity is greatest in the F-2 fraction, and the antimicrobial and antitumor activities are greatest in the F-3 fraction.

• Journal of the Korean Society of Clothing and Textiles
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• v.9 no.1
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• pp.17-27
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• 1985

In order to investigate the warmth retaining properties of fabrics some characteristics such as thickness. porosity, packing density, thermal conductivity, moisture regain and air permeability were measured and experimental results were analysed statistically to relate the warmth retaining properties with those characteristics. From the analysis, the following results were obtained. 1. When the warmth retaining properties of fabrics (Y) are dependent variable and thickness ($x_1$), porosity ($x_2$), packing density ($x_3$), thermal conductivity ($x_4$), moisture regain ($x_5$) and air permeability ($x_6$) are independent variables, the regression equation of warmth retaining properties can be represented as follows. 1) Y= 1.6005+46.817$x_1$, (R=0.9487) 2)Y=-1.4187+26.5072$x_1$+0.2055$x_2$(R=0.9704) 3) Y= -3.6908+17.4482$x_1$+0.1782$x_2$+28.3243$x_3$ (R=0.9756) 4) Y=0.9202+16.9553$x_1$+0. 1167$x_2$+30.3577$x_3$+1.8884$x_4$ (R=0.9792) 5) Y=0.9353+17.2266$x_1$+0.1177$x_2$+28.9821$x_3$-1.8302$x_4$+0.0151$x_5$ (R=0.9792) 6) Y=0.7583+17.2343$x_1$+0.1196$x_2$+28.8830$x_3$-1.8336$x_4$+0.0187$x_5$0.0004$x_5$ (R=0.9792) 2. The warmth retaining properties of fabrics are merely affected by adding thermal conductivity, moisture regain and multiple regression equation which contains thickness, porosity and packing density as variables. Therefore the multiple regression which contains thickness, porosity and packing density as variables Y=-3.6908+17.4482$x_1$+0.1782$x_2$+28.3243$x_3$ is highly practical.

• The Journal of Korean Academic Society of Nursing Education
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• v.3
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• pp.78-98
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• 1997

Health education, as the most fundamental concept for national health promotion, alms for developing the self-care ability of the general public. High school days are regarded as the period when most important physical, mental and social developments occur, and most health-related behaviors are formed. School health education is one of the major learning resources influencing health potential in the home and community as well as for the individual student. High school health education in Korea has a fundamental systemic flaw in that health-related subjects are divided and taught under various subjects areas at school. In order to achieve the goal of school health education, it is essential to make a systematic assessment of the learner's concerns connected with his health and life, and the factors affecting them. So far, most of the research projects that had been carried out for improving high school health education were limited in their concerns to a particular aspect of health. Even though some had been done in view of comprehensive school health education, they failed to Include a health assessment of the learner. Therefore, in this study the high school students' concerns related to health and life were investigated in the first place on the basis of the PRECEDE model, developed by Green and others for the purpose of a comprehensive diagnostic research on high school health education. This study was done in two steps : one was the basic study for developing research instrument and the other was the main one. The former was conducted at five high schools in Seoul and Cheongju for 2 months-beginning in March, 1996. The students were asked to respond to questions related to their health and lives in unstructured open-ended question forms. On the basis of analysis of the basic study, the diagnostic instruments for the quality of life, health problems, health behavior and educational factors were constructed to be used for the collection of data for main study. An expert panel and the pilot study were used to improve content validity and reliability of the instruments. The reliability of the instruments was measured at between .7697 and .9611 by the Cronbach $\alpha$. The data for this study were collected from the sample consisted of the junior and senior classes of twenty general and vocational high schools in Seoul and Cheongju for two months period beginning in July, 1996. In analyzing the data, both t-test and $X^2$-test were done by using SAS-$PC^+$ Program to compare data between the sexes of the high school students and the types of high school. A canonical correlation analysis was carried out to determine the relationships among the diagnostic variables, and a multivariate multiple regression analysis was conducted by using LISREL 8.03 to ascertain the influences of variables on the high school students' health and quality of life. The results were as follows : 1) The findings of the hypothesis tests (1) The canonical correlation between the educational diagnosis variables and behavioral, epidemiological, social diagnosis variables was .7221, which was significant at the level of p<.001. (2) The canonical correlation between the educational diagnosis variables and the behavior variables was .6851, which also was significant (p<.001). (3) The canonical correlation between the behavioral diagnosis variables and the epidemiological variables was 4295, which was significant (p<.001). (4) The canonical correlation between the epidemiological diagnosis variables and the social variables was .6005, which was also significant (p<.001). Therefore, the relationship between each diagnosis variable suggested by the PRECEDE model had been experimentally proven to be valid, supporting the conceptual framework of the study as appropriate for assessing the multi-dimensional factors affecting high school students' health and quality of life. Health behavior self-efficacy, the level of parents' interest and knowledge of health, and the level of the perception of school health education, all of which are the educational diagnostic variables, are the most influential variables in students' health and quality of life. In particular, health behavior self-efficacy, a causative factor, was one of the main influential variables in their health and quality of life. Other diagnostic variables suggested in the steps of the PRECEDE model were found to have reciprocal relations rather than a unidirectional causative relationship. The significance of this research is that it has diagnosed the needs of high school health education by the learner-centered assessment of variety of factors related to the health and the life of the students. This research findings suggest an integrated system of school health education to be contrived to enhance the effectiveness of the education by strengthening the influential factors such as self-efficacy to improve the health and quality of the lives of high school students.