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An Investigation of Preferred Orientation and Microhardness of Nickel-Tin and Tin-Zinc Alloy Electrodeposits on Mild Steel (연강에서의 닉켈-주석과 주석-아연합금 전착층의 우성배향와 미소경도에 관한 연구)

  • Ahn, Deog-Su;Pyun, Su-Il
    • Journal of the Korean institute of surface engineering
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    • v.13 no.3
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    • pp.146-154
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    • 1980
  • The effects of various electrodeposition conditions (deposition temperature and cathode current density) on preferred orientation and microhardness of electrodeposited Ni-Sn and Sn-Zn alloys were studied. At deposition temperatures from 25$^{\circ}$ to 95$^{\circ}C$ and constant cathode current density of 270 and 530 A/$m^2$ Ni-Sn and Sn-Zn were codeposited in chloride-fluoride acid and stannate-cyanide alkaline electrolyte bath respectively. Ni-Sn alloy deposited at temperatures from 25$^{\circ}$ to 35$^{\circ}C$ was composed of single phase of $Ni_3Sn_4$ with 73 wt.% Sn and the one deposited at temperatures from 45$^{\circ}$ to 95$^{\circ}C$ was made of multiphase mixture of NiSn, $Ni_3Sn_2$ and $Ni_3Sn_4$ with nearly equiatomic composition (65.5 wt.% Sn). The random orientation of thermody-namically metastable NiSn phase (hexagonal structure) predominated at deposition temperature range 25$^{\circ}$-45$^{\circ}C$, and the strong (110) preferred orientation was found at 65$^{\circ}$-85$^{\circ}C$ and then disappeared again at 95$^{\circ}C$. The microhardness of Ni-Sn deposits increased with deposition temperature up to 85$^{\circ}C$, and then decreased at constant cathode current density. The preferred orientation and the maximum microhardness were discussed in terms of lattice contractile stress which result from desorption of hydrogen atom absorbed in deposit lattice. The Sn content of Sn-Zn alloy deposits increased with deposition temperature up to 75$^{\circ}C$, and then decreased at constant cathode current density of 530 A/$m^2$. It also decreased with cathode current density up to 530 A/$m^2$, and then increased at constant deposition temperature of 25$^{\circ}C$. Sn-Zn alloy deposits were composed of two-phase mixture of ${beta}$-Sn and Zn. The preferred orientations of ${beta}$-Sn (tetragonal structure) changed with deposition temperature. The microhardness of Sn-Zn deposits decreased with deposition temperature. It also increased with cathode density up to 530 A/$m^2$, and then decreased at constant deposition temperature of 25$^{\circ}C$. The microhardness of Sn-Zn deposits was observed to be determinded more by the Sn content than by the preferred orientation.

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A Study of Classified Comparison between Intravascular Laser Irradiation Therapy(ILIT) and Extravascular Laser Irradiation Therapy(ELIT) on Hypercholesterolemia (침습, 비침습 혈관레이저에 의한 고콜레스테롤혈증의 치료 효과 환자 유형별 비교)

  • Kwon, Mi-Jung;Kim, Min-Kyu;Heo, Sung-Woong;Youn, Hyoun-Min;Kim, Won-Il;Kwon, Jung-Nam;Kim, Young-Kyun
    • Journal of Pharmacopuncture
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    • v.9 no.2
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    • pp.141-154
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    • 2006
  • Objective : The purpose of this study was to compare and analyze the effect of ILIT and ELIT according to sex, age, disease on Hypercholesterolemia. Methods : The 73 patients who were irradiated to the Intravascular Laser and the 57 patients who were irradiated to the Extravascular Laser from 1999 to 2005 in Sam-se oriental medicine hospital were the study group. They were irradiated two or three times a week and checked total cholesterol before and after ten times of irradiation. The checked total cholesterol point, 150-199 were normal, 200-239 were borderline, over 240 were abnormal. They were classified into male and female(43 persons, 87 persons), adult and 01d(62 persons, 68 persons), cardiovascular disease and the other diseases(70 persons, 60 persons). Results : 1. Male, adult, and the other diseases groups were more effective in cholesterol reduction and in convertible change of each group than female, old, and cardiovascular disease groups, but only the convertible change of each group had statistic significance. 2. In male, old, and cardiovascular disease, ELIT was more effective than ILIT in cholesterol reduction and convertible change of each group, but this result didn't have statistic significance. 3. In female, ELIT was more effective than ILIT in cholesterol change but this result didn't have statistic significance. ILIT was more effective than ELIT in convertible change of each group and this result had statistic significance. 4. In adult and the other diseases, ILIT was more effective in cholesterol reduction, but this result didn't have statistic significance. ILIT was more effective than ELIT in convertible change of each group too and this result had statistic significance. Conclusion: It was thought to be undesirable to decide which is more effective treatment, but to be more desirable to choose one of ILIT or ELIT according to sex, age, disease than to decide it indiscriminately.

The Production-And-Marketing System and the Regional Division in a Traditional Industrial District: Hemp Fabric Handicrafts in Andong (안동 삼베 수공업산지의 생산유통체제와 지역분화)

  • Lee, Chul-Woo
    • Journal of the Korean association of regional geographers
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    • v.3 no.1
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    • pp.135-154
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    • 1997
  • The purpose of this study is to clarify the reason of the change of production-and-marketing system and of the regional division. The data for this study were collected by administering interviews with people engaging in hemp fabric industry: namely, craftsmen and managers in the production and marketing of "hemp fabric" handcraft. The summary of this study is as follows: First, the hemp fabric industry is a main subsidiary business of agriculture in Andong. The process of making hemp fabric heavily depends on manual labor. The process is divided into five stages: namely, cultivating hemp, pre-reeling, reeling, weaving, and colouring. Second, Andong "hemp fabric" handicrafts industry had been continuously growth until the late 1960s. During the period of Japan colonization, it was under boom condition: while the other traditional fabric industries were declined. In the 1970s, the decrease of the demand of hemp fabric was the result of mass production of substitute goods on factory system: while, in the 1980s, the growth of per capital income play an important role in bringing about the increased demand of hemp fabric. Third, in the 1980s. production-and-marketing system was changed as the result of the effort to improve the quality and the process, the advanced age of craftsmen, and the weak function of existing marketing systems. The social division of labor within the district is well developed between cultivating hemp, reeling and weaving. The social division of labor is also found in the partly process of handcratfs, and between the production and marketing. The social division of labor between production and marketing is not strongly developed to establish a reliable enterprise that develops a new product and opens a new market. Fourth, the spatial boundary of the production of hemp fabric handcrafts becomes limited into a special region based on the regional specialization of hemp cultivating and the differentiation of utilization of labor.

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A Study of Characteristics of Seeding Plants through Improvements of Dredge Vegetation-Base -Focus on Site 14 in Nakdong-gang- (준설토 파종식물의 생육경향 및 관리방안 연구 -낙동강 14공구 중심으로-)

  • Kim, Nam Choon;Ann, Phil Gyun;Nam, Sang Jun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.1
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    • pp.141-154
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    • 2012
  • This study was launched to verify the effective composition of plant species and its management program most suited for the dredged soiled area near Nakdong River Site 14. The improvement methods of planting base and the composition of plants such as silver grass, reed, and some colonies in aesthetic effect were studied. To search the management methods to decrease the confining pressure risen from the burried seeds which would consequently harm the previously seeded plants, experimental construction process was measured on the site. The purpose of this experiment was to figure out which part of the improvement on the plant base has the most significant effect for the revegetation of infertile, dredged soil, to verify the easily seeded, developing plants among seeded plants, and finally, to find the restoration model using plants near the dredged soil around riverside. 8 seeded plants and 23 invaded species were appeared which among the emerged plants, development of Aster yomena MAKINO, Lotus corniculatus var. japonica Regel, Trifolium repens L, and Dianthus longicalyx Miq were proved to be brought up well. Difference risen from the seed composition were not noticeable until 150day since the germination was proceeded mainly by Aster yomena MAKINO. The experimental plot with dredging sand+organic fertilizer method of construction and dredging sand+soil conditioner method showed most development while the effect of the plot with only the soil base of dredging sand stayed low. Another important method for the management of infertile, dredged soil base would be the removal of disturbing species which the experiment showed the tied relationship between the removal of disturbing species and development of seeding plants. Although this study was carried out focused on the Nakdong River Project, the study suggests the general management program that the removal of disturbing species such as Humulus japonicus Sieboid & Zucc. and Pueraria lobata (Willd.) Ohwi in times around rainy season(60days after seedling) would be effective for the easy growth of revegetation plants.

Studies on the Growth of Excised Root between Indica- Japonica Hybrids and Japonica Type in Paddy Rice (통일형수도와 일본형수도에 있어서 종근.분리근의 생육에 관한 연구)

  • 김진호;서인석;이성춘
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.2
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    • pp.147-154
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    • 1989
  • The experiments were carried out to compare the growth characteristics of excised seminal roots in Japonica type, Indica- Japonica hybrids and its parents. Based on the modified culture medium by Kawata et al., several levels of pH. sucrose and casamino acid were varied in the culture media. The excised root length at 27$^{\circ}C$ incubator was little different between Japonica type and Indica-Japonica hybrids, but at 30$^{\circ}C$ incubator the excised root elongation of Indica-Japonica hybrids was much better than that of Japonica type. The dry matter weight of excised root in Indica- Japonica hybrids was significantly heavier than in Japonica type at both 27 and 30$^{\circ}C$ incubators. The difference of dry root weight between Japonica type and Indica- Japonica hybrids was caused from the number of lateral roots, especially the root numbers of 25 cm length. The main and lateral seminal root growth of Japonica type grew best at the lot of 0.2 percent casamino acid. However, the lots of 0 and 0.2 percent casamino acid showed good results in the main and lateral excised root growth. respectively of Indica-Japonica hydrids. The growth of excised roots was better in Indica-Japonica hybrids than in Japonica type at even various levels of pH, sucrose and casamino acid. Between the parents of Indica - Japonica hybrids, the excised root growth of Indica type was more predominant than that of Japonica type, and the effect of casamino acid on the excised root growth in the formar was similar to that of Indica type. This result indicated that the growth characteristics of excised seminal roots in Indica Japonica hybrids were derived from the parent, Indica type.

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Effect of Addition of Koji on Quality of Amino Acid Soysauce (국(麴)의 첨가가 아미노산간장의 품질에 미치는 영향)

  • Kim, Chan-Jo;Lee, Suk-Kun;Lee, Jong-Soo;Park, Chang-Hee
    • Applied Biological Chemistry
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    • v.31 no.2
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    • pp.154-161
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    • 1988
  • In order to improve the quality of amino acid soysauce, this experiment was carried out as follows; koji added amino acid soysauce(KAAS) was prepared by addition of defatted soybean and meal koji into amino acid soysauce containing $0.5%{\sim}1.5%$ of total nitrogen. Various physicochemical characteristics of KAAS during aging were determined. Total nitrogen, amino-nitrogen, specific gravity, pure extract, total acidity and color were high in KAAS at high total nitrogen. After one month aging, reducing sugar was high in KAAS at high total nitrogen, but pH was high in KAAS at low total nitrogen. Ethyl alcohol was 2.07% in KAAS at 0.5% of total nitrogen after five months aging and 1.4% in KAAS at 1.5% of total nitrogen. Levulinic acid and lactic acid were high in KAAS at low total nitrogen. The results obtained above summarized as the quality of KAAS were highly good at $0.5{\sim}0.7%$ of total nitrogen after two or three months aging.

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A Study on Room Assignment Considering Accessibility in a University Dormitory: A Case Study for University A (공용 공간의 접근성을 고려한 대학 기숙사 공실 배정에 관한 연구: A대학교를 중심으로)

  • Kim, Na Yeong;Lee, Jinho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.148-154
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    • 2020
  • This study examines room assignments to improve accessibility in a university dormitory depending on the student grade, taking into account frequency of using a certain common space. An integer programming model is presented to minimize the total moving distance from the common space to the students' rooms for accessibility. The model also constrains the maximum capacity of a room, and disallows different grade students to be assigned to the same room. This model is similar to a facility location problem used widely in the supply chain management field. Applying our optimization model to a small group at the dormitory of Unversity A as the case study, our results indicate that lower grade students are assigned rooms closer to the common space due to their higher frequency of using that space to guarantee high accessibility. Moreover, if higher grade students are prioritized to select their rooms, we suggest an objective function that imposes a penalty in cases when lower grade students select rooms with priority. Based on the results obtained, we propose assigning rooms to students in a dormitory by considering their complex requirements and convenience to use the common space.

Research of a plan setting Secondary School Teacher Recruitment Test of Electricity·Electronics·Communication Subject (중등교사 임용시험 전기·전자·통신 과목의 출제방안 연구)

  • kim, Jinsu;Rho, Taechun;Ryu, BungRho;Eun, Taeuk
    • 대한공업교육학회지
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    • v.31 no.2
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    • pp.128-154
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    • 2006
  • In the knowledge-based society, the quality of education is the core factor of national development. Above all, for improving educational quality, it is important to advance teacher's quality. Therefore, in order to maintaining high-level quality of education, it is required to select and appoint competent teacher. It deserves emphasis on importance of teacher recruitment test for maintaining high-level quality of education in this changes of age. Specially, Secondary School Teacher Recruitment Test of Electricity Electronics Communication Subject is declined qualitatively as each Subject of Electricity Electronics Communication is integrated and criterion of examination is obscured. This research analyzed The seventh curriculum and curriculum of Institution of Teacher Education of Electricity Electronics Communication Subject and already known examination of it On the basis of analyzing result, A field, proportion and points of examination decided through a expert conference are as follow: first, Teacher Recruitment Test of Electricity Electronics Communication Subject consists of subject pedagogics and contents. a proportion of subject pedagogics is 20% and subject contents is 80%. second, a subfield of subject contents consists of industrial education, industrial curriculum, industrial instruction method, practical guidance method, management of practical field organization, assesment of industrial education, industrial-educational cooperation and vocation and career education. third, subject contents consists of a common special, foundation special and application special field. a common a proportion of special field is 7.4%, foundation special is 20% and application special field which consists of electric field(21.3%), electronic field(21.3%) and communication field(10%) is 52.6%. fourth, Teacher Recruitment Test of Electricity Electronics Communication Subject execute practical technique test after finishing writing test.

The Forecasting a Maximum Barbell Weight of Snatch Technique in Weightlifting (역도 인상동작 성공 시 최대 바벨무게 예측)

  • Hah, Chong-Ku;Ryu, Ji-Seon
    • Korean Journal of Applied Biomechanics
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    • v.15 no.3
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    • pp.143-152
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    • 2005
  • The purpose of this study was to predict the failure or success of the Snatch-lifting trial as a consequence of the stand-up phase simulated in Kane's equation of motion that was effective for the dynamic analysis of multi-segment. This experiment was a case study in which one male athlete (age: 23yrs, height: 154.4cm, weight: 64.5kg) from K University was selected The system of a simulation included a multi-segment system that had one degree of freedom and one generalized coordinate for the shank segment angle. The reference frame was fixed by the Nonlinear Trans formation (NLT) method in order to set up a fixed Cartesian coordinate system in space. A weightlifter lifted a 90kg-barbell that was 75% of subject's maximum lifting capability (120kg). For this study, six cameras (Qualisys Proreflex MCU240s) and two force-plates (Kistler 9286AAs) were used for collecting data. The motion tracks of 11 land markers were attached on the major joints of the body and barbell. The sampling rates of cameras and force-plates were set up 100Hz and 1000Hz, respectively. Data were processed via the Qualisys Track manager (QTM) software. Landmark positions and force-plate amplitudes were simultaneously integrated by Qualisys system The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 9Hz calculated with Andrew & Yu's formula. The input data of the model were derived from experimental data processed in Matlab6.5 and the solution of a model made in Kane's method was solved in Matematica5.0. The conclusions were as follows; 1. The torque motor of the shank with 246Nm from this experiment could lift a maximum barbell weight (158.98kg) which was about 246 times as much as subject's body weight (64.5kg). 2. The torque motor with 166.5 Nm, simulated by angular displacement of the shank matched to the experimental result, could lift a maximum barbell weight (90kg) which was about 1.4 times as much as subject's body weight (64.5kg). 3. Comparing subject's maximum barbell weight (120kg) with a modeling maximum barbell weight (155.51kg) and with an experimental maximum barbell weight (90kg), the differences between these were about +35.7kg and -30kg. These results strongly suggest that if the maximum barbell weight is decided, coaches will be able to provide further knowledge and information to weightlifters for the performance improvement and then prevent injuries from training of weightlifters. It hopes to apply Kane's method to other sports skill as well as weightlifting to simulate its motion in the future study.

A Study on the Educational Effectiveness of Chronic Diseases Among University Students (일부 대학생들의 성인건강 교육의 효과에 관한 연구)

  • Kang, Hee-Sook;Cho, Hyun
    • Journal of the Korean Society of School Health
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    • v.8 no.1
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    • pp.143-154
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    • 1995
  • Korea has been recently reducing the quality of life as well as rising medical cost because of the increase of chronic diseases. But we can prevent those chronic diseases through the improvement of environment or life style. We evaluated the educational effectiveness of chronic diseases(hypertention, diabetes, cancer, stroke and other chronic diseases) designed to increase the knowledge, attitude and practice of chronic diseases among university students. Between August 1994 and November 1994, we implemented chronic diseases prevention instruction in intervention students; unmatched control students were selected in same university. We conducted pre- and post-intervention surveys both intervention and control students with self-reported questionnaires(50 items). We assigned score(0-4 points) to items and conducted a analysis of covariance(ANCOVA) with sex, grade and economic status as the covariate, using the SAS PC computer statistical package. And we culculated odds ratio with safety scores between intervention and control students. The results of this study were followed. 1. In demographic characteristics of subjects both pre- and post intervention, we found no significant differences in intervention and control students at religion, father's education, mother's education, mother's occupation and type of residence(p>0.05), but we found significant differences at sex(p<0.001), grade(p<0.001) and economic status(p<0.05). 2. The sex, grade and economic status-adjusted mean prevention knowledge scores for diabetes and stroke increased from the pre- to post-survey in the intervention students(p<0.001), but control students did not increased(p>0.05). As odds ratios in knowledge were below 1, the knowledge of intervention students were higher than control students. 3. The attitudes for general adult health increased from the pre- to post-survey in the intervention students(p<0.05), but control students did not increased(p>0.05). As odds ratios in attitudes were approximately 1, we can not say effectiveness in intervention students 4. The pratices for cancer and stroke increased from the pre- to post-survey in both the intervention and control students(p<0.001). Also odds ratio of hypertention was 0.91, and that of stroke was 1.14. 5. Health related behaviors did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). But odds ratio of drinking was 0.76 and that of body weight was 1.21. 6. Health status did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). As odds ratio of health status was 1.09, prevention education was not effect in intervention students We would like to recommend as follows; 1. University students must learn about prevention of chronic diseases. Because the knowledge of invetervention students was higher than that of control students. 2. The prevention education of chronic diseases should be taught from primary school. 3. Adult health education for university students must be practiced continuously. Education period(l5 weeks) in this study was not complete. 4. The evaluation of chronic diseases was conducted real measurement(such as BP check) as well as self reported-survey. 5. Educational materials(video tape, pamphlet) related the prevention of chronic diseases should be developed at national level. And we must easely use those materials. 6. The prevention education of chronic diseases should be made through mass media as well as school education.

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