Wire Saw 슬러리로부터 Si와 SiC의 선택적 회수

한승열,이종대,전진혁,박노국,이태진,류시옥 嶺南大學校 工業技術硏究所 2004 工業技術硏究所論文集 Vol.32 No.1

This study was focused on the recovery of Si and SiC from wire saw slurry in wire saw slicing process. In order to separate Si and SiC from wire saw slurry, alkali dissolution method was used and then Na₂O showed superior dissolution property of Si. At this time, SiC was separated as powder from alkali aqueous solution. Si was dissolved as a liquid in alkali aqueous solution. After removing SiC powder, the powder was obtained by drying alkali aqueous solution and then it's XRD analysis showed that it was the water glass (Na₂SiO₃).

Controlled infiltration profile of SiC coating layer on graphite by Si vapor deposition reaction

Kuk-Jin Hwang,Si-Young Bae,Kyoung-Ho Kim,Yoon-Cheol Lee,Jung-Tae Hwang,Heesoo Lee,Seong Min Jeong,Myung-Hyun Lee 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.2

SiC-coated graphite was successfully fabricated at different temperatures (1300-1600 oC) through a silicon vapor depositionreaction (Si-VDR) process. Si powder was used for the Si source of the SiC coating layers. When Si powder was evaporatedat high temperature near the melting point of bulk Si, Si gases are moved and changed into Si liquid at the surface of thegraphite. The high-temperature process facilitated the formation of SiC coating layers on the graphite. The microstructural,mechanical, and thermal oxidation properties of the coated graphite were investigated.

Wire Saw 슬러리로부터 Si, SiC 분리 및 제올라이트 합성에 대한 연구

한승열,이종대,박노국,이태진,류시옥 한국공업화학회 2004 응용화학 Vol.8 No.1

This study was focused on the separation of Si and from Wire Saw Slurry in Wire Saw Slicing process and synthesis of zeolite by mixing with water glass obtained from its process and Alumina. In order to separate Si and SiC from Wire Saw Slurry, Alkai disslution was used and then Na₂O showed superior dissoluble property of Si. At this time, SiC was separated as powder from Alkali apueous solution. Si was dissolved as a liquid in Alkali aqueous solution. After removing SiC powder, the powder formed was obtained from drying. Alkali aqueous solution and then it was the water glass (Na₂SiO₃)confirmed by XRD analysis. Water glass (Na₂SiO₃) and Alumina mixed with pure water made as a synthesis of zeolite through the crystallization by aging and hydrothermal reaction. The manufactured zeolite was Sodium Aluminum Silicate Hydrate confirmed by XRD analysis.

VoIP(Voice over IP)서비스 품질관리 방안 연구

노시춘,김태은 남서울대학교 2009 남서울대학교 논문집 Vol.15 No.2

VoIP service is divided into H.323 related service and SIP related service. Development of multimedia service for VoIP is in the process going beyond the utilization phase of voice service. This research proposes that VoIP QoS can be provided by managing the weakness of VoIP related protocol with design of measurement management process model for VoIP QoS. Furthermore, it proposes the use of analysed item and quality item driven per voice service from VoIP service quality measurement value of the site utilizing VoIP service can increase the quality. This research is finding the meaning and assignment of VoIP QoS to deduct how to manage the control system and presenting the QoS control process and trial framework. The trial framework is the modeling of the QoS measurement metrics, the measurement time schedule, the section, hierarchy, instrument, equipment and method of measurement and the series of cycle & the methodology about analysis of the result of measurement. Measurement result can be used for improvement of VoIP service quality of both service provider and user. However, if end user wants to measure the overall quality, not only IP network to be measured but also the Gateway. To acquire quality of VoIP, continuos development of efficient measurement method and measurement item to clearly indicate the quality level of service and performance of network, and applying of such development is necessary. Keywords : VoIP, QoS, framework

‘잘 모르겠음’ 답지와 추측에 대한 차별점수화가 차별기능검사와 피험자 응답 적합도에 미치는 영향

시기자,이유미,성태제 이화여자대학교 교육과학연구소 2007 교육과학연구 Vol.38 No.3

선택형 검사는 피험자가 추측에 의하여 응답할 수 있는 단점을 지니고 있으며, 추측에 의한 응답은 피험자 능력추정의 오차를 증가시킬 뿐 아니라 검사의 양호도에도 영향을 미친다. 이 연구에서는 추측에 의한 응답을 줄이기 위해 ‘잘 모르겠음’이라는 답지를 포함하는 것과 오답과 ‘잘 모르겠음’이라는 응답에 대해 차별적으로 점수를 적용하는 방안이 검사의 측정학적 특성에 어떠한 영향을 미치는지 차별기능검사와 피험자응답 적합도 측면에서 살펴보고자 하였다. 이를 위해 아무런 처치도 가하지 않은 집단과 ‘잘 모르겠음’이라는 답지를 포함한집단, 추측한 응답에 대해 차별점수를 적용한다고 공지한 집단으로 구분하여 검사를시행하였다. 추측에 대한 차별점수화의 영향을 알아보기 위하여 오답과 ‘잘 모르겠음’답지에 대한 차별점수화를 공지한 집단의 경우 자료처리에 있어서는 차별점수를 적용하는 조건과 적용하지 않는 조건으로 구분하였다. 분석결과, 4가지 조건 중 ‘잘 모르겠음’이라는 답지를 포함하고 있는 조건에서 피험자 응답 적합도가 보다 양호한 것으로나타났으며, 동일한 내용을 측정하는 검사라 할지라도 추측에 의한 응답을 고려하지않는 검사 유형과 비교할 때 ‘잘 모르겠음’이라는 답지를 포함하거나 ‘잘 모르겠음’이라는 답지를 포함하면서 추측에 대한 차별점수화를 예고할 경우 검사가 달리 기능하는것으로 분석되었다. The primary purpose of this study is to investigate the effects of ‘don't know’response option and differential scoring for ‘don't know’ response on DTF andperson fit, and to detect the methods to reduce the effect of guessing inmultiple-choice test. Three forms of each test unit were prepared. The group 1 took forms containingitems with five responses and the group 2 took forms which had an additionalresponse of I don't know, while the group 3 took forms with ‘don't know’ responseoption and information of weight on the choice of ‘don't know’ option. The group3 data is processed to study the effect on weight by two methods to weight of‘1/number of alternative’ for ‘don't know’ response and not to. Person fit shows good result in the case of addition of a ‘don't know’ option. Also, even though tests are constructed by the same items, there are the effectsof ‘don't know’ response option and the information of differential scoring for‘don't know’ response and tests differently function.

大學生의 結婚觀 變化에 關한 硏究

柳時中,金基兌 부산대학교 학생생활연구소 1976 硏究報 Vol.12 No.1

This is a comparative study of values among unmarried university students based on dated from the years 1963, 1969 and 1975. The content is as follows: Ⅰ. Attitudes on premarital dating, and values and practice regarding virginity 1) The tendency to view marriage as a necessity has undergone a significant change. In 1963,89.05 of informants saw marriage as a necessity while in 1969 and 1975 the frequency was 86.0% and 71.3%. Of course the central tendency is still in the direction of marriage as a ordinary life goal. 2) In 1963, the majority of both men and women students favored dating before marriage but men showed a greater tendency to favour dating than women. In subsequent years there was an increase in the number of women favoring dating and adecrease in the number of men. By 1975, however, the percentage of both men and women who faver premarital dating was almott the same. 3) Over all three periods the central tendency is for men to favor a double standars in regard to premarital virginity and for women to oppose a dpuble standard. However, eyer this peripd there is a slight change. Fewer men require the observance of premarital virginity for women, while at the same time women are inclined to concede a double standard to men. However, women still are in favor of premarital virginity for women. 4) During the research period. investigation indicates that more than 73% of the men had premarital sexual experience and about 10% of the women. However, the frequency with regard to women is based on interpertation of the responce "cannot reply" as indicative of premarital experience. This interpretation is of course open to question. In any event the data indicates that practice is generally congruent with value.Ⅱ. Methods and conditions for selecting a spouse . 5) In two periods (1969, 1975) the central tendency on the part of both men and women was to favor a combination of arranged marriage and a love mix match i. e., although a go-between is utilized at same point in marriage arrangements, the marriage dose not take place without some degree of positive affect on the part of both parties. However, the research reveals a change in that more women have come to prefer a love match. 6) When asked about who should make the final decision to contract a marriage both men and women were in favor of some form of cooperation between parents and children. Men tended to feel that the children should decide with parental consent: Women tended to feel that parents should decide with the childrens' consent. There is a change in value on the part of men in the direction of independent decision making, also more women now think that children should make the decision with the consent of their parents. 7) Over 10% of the respondents in all three periods indicated the necessity of using the traditional method of divination (崙合) to determine if the couple are suitable marriage partners. 8) Previously there was a tendency on the part of Korean woman to discriminate in the choice of marriage partners on the basis of order of birth, e. g. marriage to a first son was considered undesireable because it required residing with his parents and bearing additional responsibilities. Our study indicates a weakening in this tendency, toward less discrimination on the basis of birth order. 9) In regard to the appropriate age for marriage most men favored the age of 27 or 28 while women favor 23 or 24. The mode for all three periods is the same but we discovered a widening in the range of appropriate ages for men. There is no widening in the range of appropriate ages for women. 10) Asked to indicate preferrrd characteristics of potential partners both men and women gave greatest weight to the following : personal chararter, health and education in that order. In addition, physical appearance, occupation. and financial status in that order were chosen by men; women chose the same three characteristics but in the following order: occupation, fanancial status, physical appearance. Ⅲ. Plans for marital life 11) Both men and women tend to favor having just two children, the ideal being a son as first berm followed by a daughter. Women especially have come to favor smaller families. There is also a notable tendency toward no preference in regard to the sex of children. 12) Data from 1963 is also lacking regarding the question of how decisions should be made regarding family and houshold affairs. In the other two periods no change was indicated. Men continued to believe that husbands should decide after hearing the wife's opinion. Women continued to believe that both husband and wife should decide together. 13) Data from 1963 is lacking regarding opinion concerning responsibility for family income. In the other two periods the central tendency was to favor entrusting most of the income to the wife with the husband keeping a part for his own use. 14) The data from 1963 and 1969 indicates a tendency on the part of broth sexes to oppose residence with the parents of the hunband. Women show show definite tenency to favor residence will parents of the husband and men also show an increase in this regard. Perhaps, having experienced some inconvenience in following the conjugal family pattern there is some reversal in the direction of a modified form of the traditional pattern.

Arsenazo I-XAD-2 킬레이트수지를 이용한 U(VI) 이온의 분리 및 농축에 관한 연구

엄태윤,김인환,이창헌,강창희,이시은,이원,임재희 濟州大學校 基礎科學硏究所 1994 基礎科學硏究 Vol.7 No.1

Aresenazo I-XAD-2 킬레이수지를 합성하고 이 수지에 대한 U(VI)이온의 흡착 거동을 조사 검토하였다. 킬레이트수지는 Arsenazo I 킬레이트제와 Amberlite XAD-2의 디아조늄짝지움 반응에 의해서 합성하였으며 원소 분석법과 적외선 분광법으로 확인하였다. U(VI)이온흡착의 최적 조건을 찾기 위해서 pH, U(VI) 이온농도와 진탕 시간에 관해서 조사하였다. U(VI)이온에 대한 킬레이트수지의 전체 흡착능은 pH 4.0∼4.5 범위에서 0.39mmol U(VI)/g resin이었고, pH값이 증가함에 따라 흡착능이 증가하였다. Arsenazo I-XAD-2 킬레이트 수지에 대한 U(VI)이온의 흡착 메카니즘은 U(VI)이온과 H+ 이온 사이의 경쟁반응임을 확인하였다. 컬럼법으로 구한 U(VI) 이온의 돌파점 부피와 전체 흡착능은 각각 600ml, 0.38mmol U(VI)/g resin 이었다. 3M HNO₃와 3m Na₂CO₃의 탈착용액을 사용하여 구한 회수율은 90∼96%였다. 따라서 본 연구에서는 합성한 Arsenaso I-XAD-2 킬레이트수지는 자연수 바닷물 중에 함유된 U(VI)이온의 분리와 농축에 매우 유용함을 알았다. Some sorption behaviors of U(VI) ion on Arsenazo I-XAD-2 chelating resin were investigated. This chelating resin was synthesized by the diazonium coupling of Amberlite XAD-2 resin with Arsenazo I chelating reagent and characterized by elementary analysis method and IR spectrometry. The optimum conditions for the sorption of U(VI) ion were examined with respect to pH, U(VI) ion concentration and shaking time. Total sorption capacity of this chelating resin on U(VI) ion was 0.39 mmol U(VI)/g resin in the pH range of 4.0∼4.5. This chelating resin was showed increased sorption capacity on the increased pH value. It was confirmed that sorption mechanism of U(VI) ion on the Arsenazo I-XAD-2 chelating resin was competition reaction between U(VI) ion and H+ ion. Breakthrough volume and overall capacity of U(VI) ion measured by column were was 600ml and 0.38 mmol U(VI)/g resin, respectively. The desorption of U(VI) ion was showed recovery of 90∼96% using 3M HNO₃and 3M Na₂CO₃as a desorption solution. The separation and concentration of U(VI) ion from natural water and sea water was performed successfully by Arsenazo I-XAD-2 chelating resin.

GIS를 이용한 산불발생위험지역 구분

이시영,안상현,원명수,이명보,임태규,신영철 한국지리정보학회 2004 한국지리정보학회지 Vol.7 No.2

산불로 인한 재해를 미연에 방지하고 피해를 저감하기 위해서는 산불발생위험지역을 사전에 파악하여 예방대책을 세울 필요가 있다. 따라서 본 연구에서는 산불발생인자에 따른 산불발생위험지역을 구분하고자 겸상북도 의성군에서 발생한 산불피해지역에 대하여 임상, 지형 등에 대하여 조사하였다. 조사된 요인들 간 독립성 유무를 상관분석을 이용하여 산불발생과 관련 있는 7개의 주제도를 선정하였으며, 선정된 주제도를 조건부확률과 지리정보시스템을 이용하여 산불발생확률을 계산하였다. 계산된 산불발생확률을 20개 등급으로 지수화하여 산불발생위험지역을 구분하였다. In order to decrease the area damaged by forest fires and to prevent the occurrence of forest fires, we are making an effort to improve prevention measures for forest fires. The objective of this study is to classify hazard regions where forest fires occur based on the factors that contribute to the occurrence of forest fires. Forest fire sites in the Uiseong-gun, Gyeongsangbuk-do were surveyed according to the factors of forest type and topographic characteristics where the forest fires occurred. We used a correlation analysis to determine the forest fire occurrence factors and a conditional probability analysis and GIS to determine a forest fire danger index. The resulting forest fire danger index was used in the classification of forest fire occurrence risk regions.

저합금 주강품의 열처리 해석

김정태,김정인,곽시영,최정길 한국주조공학회 2003 한국주조공학회지 Vol.23 No.6

오리 선위 점액분비세포의 점액질에 대한 조직화학적 연구

류시윤,김홍선,김무강,신태균,이영호 충남대학교 의과대학 지역사회의학연구소 1985 충남의대잡지 Vol.12 No.2

Histochemical sequential staining techniques, PAS, alcian blue pH 2.5 and pH 0.4, were applied to sections from the proventriculus of ducks to observe the histochemical properties of epithelial mucosubstances in the proventriculus of mallard and white Pekin ducks. The whole proventriculus obtained were divided systemically cross strips and processed routinely for histologic and histochemical study. Base on the histologic characteristics, we designated as upper portion which is the distal region of the esophageal-proventriculus junction, as middle portion, and as lower portion which is the proximal region of the proventricular-isthmus junction. The results obtained are as follows 1. Generally in the surface and foveolar epithelia showed the presence of the mixture of neutral and acid mucosubstances. 2. In the tubular gland showed the acidic nonsulfated and sulfated mucosubstance in addition to neutral mucosubstances with occasional neutral and acidic nonsulfated mucosubstances. 3. In the compound gland neutral mucosubstance with scant amounts of acidic mucosubstances or with lack of it were demonstrated. 4. There were recognized differences between speies in the staining intensity of all three types of mucosubstances. 5. There were recognized topographic difference in the acidity of epithelial mucosubstances according to portion.