• 청정기술
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• 제2권1호
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• pp.96-108
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• 1996

질산과 불산의 혼산용액을 사용하는 스테인레스 산세 공정에서 많은 $NO_x$가 발생하고 이로 인한 주위환경의 피해가 우려되어 왔다. 본 연구는 이미 생성된 $NO_x$를 제거하는 기존의 환경공학 연구와 달리, 청정기술 개발의 일환으로 기존 산세 공정을 일부 변경하여 $NO_x$ 생성을 저감하기 위한 연구이다. 연구내용은 크게 둘로 나누어지는데, 첫째로 산세 공정의 다양한 공정 변수가 $NO_x$ 생성에 어떻게 영향을 주는 가를 파악하였고 둘째로 $NO_x$ 생성 억제제인 과산화수소가 $NO_x$ 발생량에 미치는 영향을 조사하였다. 중요 결과로는 산세 공정에서 $NO_x$ 생성에 영향을 미치는 주요 산세공정 변수는 불산 농도, 반응 온도이며 $NO_x$ 발생의 원인 물질인 질산 농도의 영향은 불산 농도에 비하여 크지 않다. 합성 혼산의 경우 산세를 하지 않는 동안에도 $NO_x$를 발생시키나 그 양은 무시할 정도이다. 그러나, 산세 현장의 산세 용액은 산세를 하지 않는 상태에서도 $NO_x$ 발생은 크다. 산세 공정에서 과산화수소 첨가에 따른 $NO_x$ 생성의 저감은 매우 효과적이어서 과산화수소의 농도가 스테인레스 시편 면적에 대하여 $9.51{\times}10^{-2}\;mole/m^2$ 이상일 때 $NO_x$ 발생이 약 80%까지 저감이 되었다. 이러한 결과는 실공정으로 운영되는 스웨덴 AVESTA 산세공정에서 비슷한 정도의 $NO_x$ 생성 저감률을 가져오기 위한 단위산세면적당 과산화수소 주입량의 1/6 정도이다. 실험실에서 행해진 과산화수소 주입에 따른 $NO_x$ 생성저감 결과를 이용하여 단위 산세면적에 대한 경제적인 과산화수소 주입양을 나타내는 영역을 설정하였다.

• 대한의료기공학회지
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• 제8권1호
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• pp.96-114
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• 2005

This study was carried out to provide essential data for the future health promotion projects to be aimed at improving quality of life for the elderly people in the increasingly aging society of Korea by investigating factors related to the yangseng of old people in urban areas. The results of this study are to be used as basis for efficient approach toward health promotion projects for the elderly in urban communities. For the purpose, a survey by questionnaires was conducted to urbanites from May th June 2004. The collected replies were analyzed from the viewpoints of Oriental Medicine for yangseng. 1. The average points of health care were 3.24. In details by sub-areas, 3.78 was rated for morality yangseng, 3.29 for mind, 3.30 for diet, 3.79 for activity and rest, 2.32 for exercise, 3.72 for sleeping, 2.95 for season and 1.81 for sexual life, which showed that the area of activity and rest yangseng was scored highest while the area of sexual life yangseng was rated lowest. 2. As for the extent of health care depending on the characters of subjects, higher scores were rated by men than women, younger ones than aged and spoused ones than singles. Married couples living without other family members were found to yangseng most, while more yangseng was taken by the educated, job holders and those who utilize leisure and have religion in order. 3. Men exercised more yangseng than women in the diet, exercise and sleeping. By age, the group aged 65 to 69, the more yangseng in the exercise and sexual life. The group with spouse featured higher concern for yangseng in all categories except for season. Married couples who are living with no other family members recorded the highest point in all areas except for exercise. 4. The more one is educated, the more he/she is tended to take yangseng in the sub-areas of exercise and sexual life. The group with occupation is also inclined to take more yangseng in the same sub-areas as those of the highly educated. When they pay living cost together with offspring, they appeared to be the most yangseng in season and sexual life. People who enjoy leisure showed higher yangseng in all areas except for season. Religion had a significant influence in all areas except for activity and rest yangseng. 5. Those who reply that they are confident with health and have no disease proved to have higher yangseng. Depending on whether one has disease or not, higher yangseng was confirmed in such sub-categories as mind and sleeping. Those who replied they are confident with health had higher yangseng in all areas except for season. As seen above, yangseng of the old people in the urban area is found to have different extent depending on the individual and socioeconomic characters, factors which should be seriously considered in the local health promotion projects and projects for the health of the elderly. It seems therefore necessary to launch health promotion programs and to analyze their effects to promote health care particularly in the areas of sexual life, exercise and season yangseng that featured lowest grade of yangseng in each sub-area.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.1-11
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• 2006

The aim in this study is to develop the combined EGR system with a non-thermal plasma reactor for reducing exhaust emissions and improving fuel economy in turbo intercooler ECU common-rail diesel engines. In this study, the characteristics of soot, CO and $CO_2$ emissions under four kinds of engine loads are experimentally investigated by using a four-cycle, four-cylinder, direct injection type, water-cooled turbo intercooler ECU common-rail diesel engine with a combined plasma exhaust gas recirculation(EGR) system operating at three kinds of engine speeds. The EGR and non-thermal plasma reactor system are used to reduce $NO_x$ emissions, and the non-thermal plasma reactor and turbo intercooler system are used to reduce soot and THC emissions. The plasma system is a flat-to-flat type reactor operated by a plasma power supply. The fuel is sprayed by pilot and main injections at the variable injection timing between BTDC $15^{\circ}$ and ATDC $1^{\circ}$ according to experimental conditions. It is found that soot emissions with increasing EGR rate are increased, but are decreased as the applied electrical voltage of the non-thermal plasma reactor is elevated at the same engine speed and load. Results also show that CO and $CO_2$ emissions are increased as EGR rate is elevated, and CO emissions are increased, but $CO_2$ emissions are decreased as the applied electrical voltage of the non-thermal plasma reactor is elevated at the same engine speed and load.

• 대한후두음성언어의학회지
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• 제30권2호
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• pp.112-117
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• 2019

Background and Objectives The purpose of this study was to develop the differential diagnosis scale containing items from adductor spasmodic dysphonia (ADSD) to muscle tension dysphonia (MTD) and the determine clinical utility of newly developed items. Materials and Method The four parts of pitch, redirected phonation, automatic speech and voiced sound were selected for analyzing the characteristics of ADSD in the literature. One part of tense voiceless sound was developed according to the Korean manner of articulation. The content validity was evaluated based on 5 scales (1-5 point) analysis from 30 experts. One hundred patients (50 ADSD and 50 MTD) were recorded in reading a sentence and sustained phonation. The two speech language pathologist evaluated recorded voices through a blind test using 4 scales (0-3 point) for newly developed items. Results As a result of verifying the content validity of items with experts, it was identified that the differentiated items were valid with 4.2 out of 5. Through the differential diagnosis between two groups according to the items, the correlation between sub-domains and total scores was shown as higher than 0.710. The result of analyzing the reliability on each diagnosis domain was 0.840-0.893, which showed the internal consistency of items was great. Newly developed five parts of ADSD were significantly higher than those of MTD with strong correlation (p<0.01). The reliability among the evaluators was analyzed as high with 0.892. Conclusion In this study, the differential diagnosis scale of ADSD was revealed as having validity and reliability. It is considered that it will be useful for differentiating ADSD and MTD in the clinical field.

• 한국가정과교육학회지
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• 제8권1호
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• pp.1-10
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• 1996

This study aims at finding a new home economics education which will include male and female students as its teaching objects, and then providing home economics teachers with useful materials. For this purpose I examined analized male and female the upper secondary school students’and parents’recognition and demand to the home economics education The conclusion of this study is summarized as follows： 1. There was significant difference between male students(73.7％) and female students(89.8％) in the necessity for studying Home Economics(P＜.001). In the necessity of Home Economics education, male students emphasized the spiritual part but female students emphasized the functional part. In part of parents, there was no significant difference between fathers(95.5％) and mothers(96.4％). 2. The necessity of each part in the contents of Home Economics 1) In the part of family, there was significant difference between male and female students in the true nature of family, the role and responsibility of family, and the laws relating to family(P＜.001). There was significant difference between mothers and fathers in the true nature of family and the role and responsibility of family. Fathers and male students emphasized the true nature of family and the role and responsibility of family more than mothers and female students did. 2) In the Home management and economy parts, there was significant difference between male and female students in the significance of home management(P＜.001), the relation of family to society(P＜.001), and fluctuating measures for home economy. There was significant difference between fathers and mothers in the relation of family to society(P＜.05). Fathers and male students emphasized the relation of family to society more than mothers and female students did. Mothers, male and female students emphasized the importance of the protection of consumers. 3) In the clothes part, male students emphasized the role of clothes, the disign and making of clothes(P＜.001), the present situation of the resources of clothing and the distribution of clothes (P＜.05) more than female students did. 4) In the part of food, there was significant difference between male and female students in the kinds and function of nutritive elements(P＜.05). Parents and students emphasized the importance of selecting good food. 5) In the part of housing, male students emphasized home planning, and arrangements and facilities of house more than female students did. Female students emphasized the interior of the house(P＜.05). Fathers emphasized the planning of a residential space and arrangements and facilities of a house(P＜.05) more than mothers did. 6) In the parts of human development and upbringing, and upbringing, male students emphasized the significance of being parents, family planning and the population problem(P＜.001), pregnancy and delivery(P＜.01), and the chracteristic of juvenile development(P＜.05) more than female students did. Parents and students emphasized the importance of prevention and countermeasures for diseases and the significance of being parents.

• Journal of Welding and Joining
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• 제28권3호
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• pp.92-98
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• 2010

Ferritic stainless steels, which have relatively small thermal expansion coefficient and excellent corrosion resistance, are increasingly being used in vehicle manufacturing, in order to increase the lifetime of exhaust manifold parts. But, there are limits on use because of the problem related to cosmetic resistance, corrosions of condensation and high temperature salt etc. So, Aluminum-coated stainless steel instead of ferritic stainless steel are utilized in these parts due to the improved properties. In this investigation, Al-8wt% Si alloy coated 409L ferritic stainless steel was used as the base metal during Gas Tungsten Arc(GTA) welding. The effects of coated layer on the microstructure and hardness were investigated. Full penetration was obtained, when the welding current was higher than 90A and the welding speed was lower than 0.52m/min. Grain size was the largest in fusion zone and decreased from near HAZ to base metal. As welding speed increased, grain size of fusion zone decreased, and there was no big change in HAZ. Hardness had a peak value in the fusion zone and decreased from the bond line to the base metal. The highest hardness in the fusion zone resulted from the fine re-precipitation of the coarse TiN and Ti(C, N) existed in the base metal during melting and solidification process and the presence of fine $Al_2O_3$ and $SiO_2$ formed by the migration of the elements, Al and Si, from the melted coating layer into the fusion zone.

• 화훼연구
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• 제16권1호
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• pp.7-11
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• 2008

본 연구는 화훼장식에서 대나무의 다양한 활용을 위해 2001년부터 2006년까지 월간잡지 플레르(Fleur)와 국제꽃장식대회의 대나무 작품 108개를 토대로 조사하였다. 대나무의 사용부위에 따른 사용빈도와 작업형태, 조형형태, 그리고 작품 안에서 대나무의 배열 기법을 분석하였다. 대나무의 사용부위는 줄기가 전체 작품에서 90%를 차지하였다. 줄기가 사용된 97작품 중에서 국제 꽃 장식 대회는 매년 4월에 열리는 특성으로 대회에 나온 20작품을 제외한 월간 잡지 '플레르(Fleur)'의 77작품을 월별로 분석한 결과, 월별 대나무가 쓰인 작품의 수는 새해의 시작인 1~2월과 한여름인 7~8월이 가장 많았다. 줄기를 사용한 97작품에서 줄기가 사용된 형태를 조사 분석한 결과, 가공하지 않고 자연그대로 사용한 작품이 63%로 나타났다. 작품 속에서 대나무의 배열 기법은 수직 병렬형이 48%로 가장 많았다. 기타는 수직, 수평, 사선에 포함되지 않는 원형의 작품들을 분류한 것이다. 대나무가 쓰인 작품의 작업유형은 테이블장식을 포함한 50% 이상이 공간장식의 형태를 나타내었다. 대나무가 소재로 쓰인 작품의 조형 형태는 장식적 형태가 64%, 그래픽적 형태가 30%, 선형적 형태가 4%로 나타났다.

• 디자인학연구
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• 제12권3호
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• pp.227-234
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• 1999

본 논문은 디자인 프로젝트 관리의 리엔지니어링으로서 프로젝트의 기획, 조직, 일정, 그리고 제어하는 통합적인 어플리케이션 소프트웨어 개발의 기초모델을 설정하고, 이를 토대로 프로젝트 관리 시스템의 연구/개발을 목표로 삼고 있다. 프로젝트의 성과, 소요기간, 소요예산, 그리고 소요자원 등을 관리하는 과정이 프로젝트 매니지먼트 기술의 근간을 이루는 것으로, 디자인 프로젝트 상의 수많은 정보를 적시에 효율적으로 처리함으로써 프로젝트를 성공으로 이끌 수 있게 된다. 한편, 디자인프로젝트의 관리를 집단의사결정에 의해 처리함으로써 신뢰도와 합리성의 제고는 물론, 이를 통한 사기앙양이 기대된다. 따라서, 여기에서 야기되는 의사집합의 곤란, 시간손실, 구성원의 갈등 등의 프로젝트 관리에서 비롯되는 부수적인 문제도 전자의 기본적인 관리요소와 함께 통합하여 디자인 프로젝트 관리 시스템(DPMS)을 연구/개발하였다. DPMS 시스템은 디자인 프로젝트의 선정과 디자인 프로젝트의 기획/실행관리/ 평가로 주요 모듈을 설정함으로써 프로젝트 매니저는 해당 프로젝트 과업(Task)과 활동(Activity)에 대한 팀의 운용을 융통성 있게 관리할 수 있게 된다. 이와 더불어 프로젝트 관리를 On-Line DBMS 시스템 환경 상에 운용되도록 하여 정보의 재생산성, 운용의 동시성, 그리고 보안성 등을 도모하였다.

• Reproductive and Developmental Biology
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• 제29권1호
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• pp.43-48
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• 2005

돼지 웅성 페르몬인 5a-androst-16-en-3-one을 대체할 수 있는 활성 분자를 탐색하여 가축의 생산과 수요를 조절하기 위한 생물학적 자극 통제 수단으로 활용하고자 냄새 분자로서 2-cyclohexyloxytetrahydrofurane (A) 및 2-phenoxytetrahydrofurane (B) 유도체들의 구조 변화와 수용체인 porcine odorant binding protein (pOBP)에 대한 결합친화력 상수(p[Od.]/sub 50/) 사이의 정량적인 구조-활성관계에 관한 분자 HQSAR 모델XI을 유도하였다. 냄새 분자 중에서 cyclohexyl-치환체(A)가 phenyl-치환체(B)보다 높은 결합 친화력을 나타내었으며(A>B) 모델XI은 분자 조각크기(5∼8), 홀로그램 길이(97 bin)의 키랄성(chirality)조건에서 예측성(q²=0.916)과 상관성(r²=0.988)이 매우 양호하였다. 기여도(contribution map)로부터 냄새 분자의 결합 친화력 상수에 기여하는 부분은 2-oxyfuryl group의 C3 및 C5 원자인 반면에 cyclohexyl 고리상 tert-butyl group의 중심 탄소 원자와 furyl group의 C4 원자 부분은 기여하지 않았다.

• 한국토양비료학회지
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• 제23권3호
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• pp.227-231
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• 1990

밭 토양(土壤)에서 개량제(改良劑)로써 Zeolite시용(施用)이 완두(豌豆)의 생육(生育) 및 질소고정(窒素固定)에 미치는 영향(影響)을 검토(檢討)코져 N. P. K 및 Zeolite등(等) 6개처리(個處理)를 vinyl house內에서 pot시험(試驗)으로 수행(遂行)한 결과(結果)는 다음과 같다. 1. 건물중(乾物重)은 질소비료(窒素肥料) 시용구(施用區)가 질소(窒素) 무시용구(無施用區)에 비(比)하여 감소(減少)되는 경향(傾向)이나 Zeolite시용구(施用區)는 오히려 증가(增加)되었다. 2. 식물체중(植物體中) 질소함량(窒素含量)은 질소(窒素)와 Zeolite을 병용(倂用)함으로써 증가(增加)되었고 Zeolite시용량(施用量)은 2%시용(施用)이 1%보다 질소함량(窒素含量)이 낮았다. 그러나 토양중(土壤中)의 질소잔재량(窒素殘在量)은 2% 구(區)에서 많았다. 3. 식물체중(植物體中)의 표식질소(標識窒素)($^{15}N$)비료(肥料)의 유래(由來)된 질소량(窒素量)은 Zeolite를 병용(倂用)하는 편이 감소(減少)되는 경향(傾向)이며 이러한 경향(傾向)은 식물체(植物體) 각(各) 부위(部位)에서도 같은 양상(樣相)을 보였다. 4. 식물체중(植物體中)의 질소고정(窒素固定)에 유래(由來)된 질소량(窒素量)은 Zeolite시용구(施用區)에서 많았다. 그러나 질소비료(窒素肥料) 시용구(施用區)에서는 그 증가량(增加量)이 적었다.