甕器類 製造時의 燒成溫度와 重金屬 溶出量과의 關係

우세홍,김선덕 서울保健大學 1981 論文集 Vol.1 No.1

옹기제조시의 소성온도에 따른 중금속의 용출량과 용출조건에 따른 중금속의 용출량을 비교 검토한 결과 다음과 같은 결론을 얻었다. 1) 藥土의 주광물질은 sericite이다. 2) 소성온도가 900℃일 때 납의 용출이 0.15~31.23ppm으로 가장 많았다. 3) 소성온도가 1400℃일 때 납의 용출량은 허용량 이하이었다. 4) 소성온도가 1200℃이상일 때 카드뮴은 용출이 방지되었다. 5) 용출조건에 따라서는 중금속의 용출량은 큰 차이가 없었다. This study was carried out to investigate the relations between the firing temperatures and the amounts of extracted lead and cadminium when enthenware is being made. As the results of this study, the following conclusions were obtained. 1) Clay used for glaze was composed of sericite, α-quarts and feldspar. 2) Great quantity of lead was extracted when earthenware was being made at 900℃. 3) The amount of extracted lead was below the acceptable level in making earthenware at 1400℃. 4) Cadminium was not leached out in making earthenware at 1200℃ and higher temperature. 5) The amount of extracted heavy metals from earthenware was affected not so much by leaching conditions as by firing temperatures.

벤처企業의 投資者保護를 위한 會社法上의 課題

禹興九,許悳會 건국대학교 법학연구소 2000 一鑑法學 Vol.5 No.-

The central task of corporation law is to protect minority shareholders. In public corporations, the problem is refered to as the separation of ownership and control. Managers, even those who own little stock, can comtrol public companies for their own benefit rather than striving to maximize shareholder wealth. Despite efforts of legislatures, and scholars to reform corporate law, the plight of minority shareholders persist. Managers of public companies remaun free to disdain shareholders, as evidenced by the deep discount from instrinsic value at which public stocks trade. In non-public, or close, corporations the issue is referred to as the opperssion of minority shareholders. Close corparations have no market for their stock, and they rarely pay dividends. Thus, minority shares are freguently worthless to hold and impossible to sell. these conditions discourage investment and prcipitate disruptive dispute in small companies. In the search for solutions, commentators have paid remarkalbe little attention to venture capitalist supplies equity financing, but does not assume control of the enterprise. A venture capitadist protets his investment through contracts. This provides a model for protecting minority investors in close corporations. Moreover, a venture capitalist's alility to supply major equity funding rivives that private financing could eclipse the public corporation. Finally, the Article demonstrates that venture capital confirms into the strength of private equity financing ; thus, venture capital has the potential to transform corporate finance. To fully realized this potential, however, the law must change to better accomondate monority investors.

한국산 개불, Urechis unicinctus의 서식생태에 관한 연구

최상덕,김호진,이원교,서호영,이우범 國立 麗水大學校 環境問題硏究所 2000 環境硏究論文集 Vol.3 No.-

For the commercial culture of marine echiuran worm Urechis unicinctus, a series of basic ecological study has been conducted for fishery period(November, 1998~April, 1999) in the laboratory and southern coast of Korea. The environmental factors of echiurans' habitat such as water temperature, salinity and dissolved oxygen were ranged 8.0~14.9 °C, 30.1~33.1 psu 7.0~8.9 ㎎/ℓ, respectively. The habitat sediments were composed of coarse sand, sand silt and silty sand. The highest densities and biomass of U. unicinctus were found in areas of the sand silt. In the laboratory, all echiurans performed burrowing success in coarse sand and sand within 24 hours, but none did in silt and clay within 10 days. In sand silt, echiurans enabled to dig 0.7~2.8 burrows/day/ind. And U. unicinctus made a burrow of U shape.

철도궤도형 구조물에서의 응력과 변위

김성득,김우식 울산대학교 2000 공학연구논문집 Vol.31 No.1

철도궤도시스템을 단순화시킨 지반위에 놓인 궤도형 구조물을 Talbot 이론 및 연속탄성 지지 모델, 2차원 Plane Strain 모델, 3차원 유한요소 입체모델 그리고 탄소성 지반위의 궤도형구조물을 기발표된 현장 실측치와 비교하여 탄성 및 탄소성 지반위에 놓인 궤도형 구조물의 해석치를 비교 검토하였다. 지반을 탄성으로 본 경우와 실상에 가까운 탄소성으로 본 경우의 수치해석 결과 하중 작용점 아래에서의 깊이에 따른 수직 처짐량이 표면에서 표면아래 50cm가지는 그 처짐량이 1.83배∼1.92배로 컸음을 알 수 있었고, 탄소성 지반위에 놓인 보에 대한 모델실험 결과와 수치해석의 결과가 거의 일치함을 확인하였다. The study compared a Track-Type Structures on soil to make simplification Railway Track System with a Talbot theory, 2-dimensional plane strain finitemodel and 3-dimensional solid model, then compared a Track-type Structures resting on the elasto-plastic soil medium with a result of elastic and elasto-plastic analysis and field test. A result of elasto-plastic analysis was confirmed larger displacement about 1.83∼1.92 times than a result of elastic analysis, this study confirmed to correspond result of model test about a beam on the elasto-plastic soil medium with result of numerical analysis.

칩브레이커 사용에 따른 밀링버의 생성특성 연구

황덕철,황준,우창기 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

This paper presents the numerical analysis and experimental verification to know the metal cutting buff formation mechanism in face milling operation. Finite element method are applied to predict the 2-D burr formation process prediction. Face milling process are adjusted to analyze the characteristics of burr shapes according to various cutting conditions. The cutting parameters were investigated with cutting speed, feed rate, depth of cut. Through a few experiments, various burr types are classified according to its shape and properties.

Angiotensin Concerting Enzyme 유전자의 유전적 다형성(Genetic Polymorphism)이 관상동맥 질환 위험인자에 따른 혈중 Plasminogen Activator Inhibitor-1의 농도에 미치는 영향

김덕경,김종원,권현절,류재춘,박승우,김준수,이상훈,홍경표,박정의,이원로 대한고혈압학회 1996 대한고혈압학회지 Vol.2 No.2

비정부기구(NGO)의 탈북자 지원 경험 분석 및 개선 방향

전우택,윤덕룡,강성록,김형중,민성길 연세대학교 통일연구원 2001 통일연구 Vol.5 No.1

Objectives: Since 1994, the number of North Korean defectors, escaping North Korea and entering South Korea, has increased rapidly.As the number of defectors has increased the role of non-governmental organizations(NGOs) in assisting the defectors' adaptation to their new society has become more important.To increase the successfulness and effectiveness of NGO activities, their experiences were surveyed and analyzed. Methods: Representatives or acting staffs of 11 NGOs presently supporting North Korean defectors' adaptation to South Korean society were interviewed by researchers between June 21 and October 14, 2000.And one focus group discussion meeting with 26 NGO personnel from 13 NGOs was held on November 4, 2000. Results: As for their stated purpose of activity; to help defectors become good citizens (7), to transform defectors into mediate personnel between North and South Korea (5), to protect the human rights of the North Korean people (3), and th advocate their religions (3).Out of the 11 organizations, only 5 had their own educational program for volunteers.The contents of the NGO's support for volunteers were as follows; counseling (7), introduction of employment and job education (6), direct financial support (5), creation of one-to-one relationships (4), assistance for their religious life (2), assistance with English study and mathematics (1), and medical service (1).NGOs listed the following difficulties; financial (7), human relationship with defectors (6), lack of volunteers and management of them (4), problems in the relationship with the South Korean government (3).NGOs stated a need for close cooperation with other NGOs, involving the activation of NGOs Association (5), and co-operative joint actions (4).Conclusion: Firstly, NGOs need to specialize in their field of activity.Their lack of specialized areas and of ability is the man obstacles to NGOs intercooperation and a major impediment on their effective operation.Secondly, NGOs should be careful in their direct financial support to defectors, because such a form of support has many serious governmental cooperation.The government also needs to have a more open mind in its dealings with NGOs.Fourthly, NGOs should cooperate, especially in areas of joint concern such as volunteer education program.Fifthly, NGOs should pay attention to their volunteers' personnel management and development.Sixthly, NGOs need to increase the degree of activeness with which defectors seek support from NGOs.Usually, it is the NGOs, which play an active role in the support process, so that defectors become passive and dependent leading to many problems.

논리회로 시뮬레이터에 있어서 실행상태의 동적 패턴 추출과 고속화

장덕진,이필우 우송대학교 부설 산업연구원 1999 산업연구 Vol.1 No.2

In general, simulation cost is enormous when the actual designs are described in hardware description languages such as VHDH. Such hardware simulation is one of the typical jobs in big computation application. Analyzing the simulation process closely, we have found that appeared pattern sequence of state transition is limited when the size of hardware modules are determinded property not be so large. The pattern sequences can be preserved dynamically when they appeared at first occurrence, and can be utilized in the later simulation in order to reduce the simulation costs. This paper proposes the basic approach of dynamic preservation and reutilization of state transitions, and presents the effectiveness of the approach based on the simulation results.

2급 1류 부정교합 환자에서 activator 유형에 따른 치료 효과에 관한 연구

김덕상,이진우,차경석 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.3

Activator는 성장기 아동에서 치성 및 악골 부조화를 개선하기 위해 성장을 이용하여 치료하는 악기능장치중 대표적인 것으로 1930년대부터 오랜 역사를 가지고 사용되고 있지만 아직까지도 그 사용여부, 작용방법, 효과에 향을 주어 골격적 관계를 변화시킨다는 의견도 있다. 현재에는 많은 논란에도 불구하고 기능성 장치가 성장중이고 협조적인 환자에서 2급 관계를 성공적으로 치료할 수 있다는 사실에 대부분 의견을 공유하고 있다. 본 연구는 하악골의 후방 변위를 보이는 Angle씨 2급 1류 부정교합 환자에서 많이 사용되고 있는 activator를 그 사용 목적에 따라 하악골의 수평적 성장을 유도하기 위한 horizontal type activator와 수평적 성장과 함께 수직적 성장도 유도하기 위한 vertical type activator로 분류하여 사용한 결과 나타나는 치료 효과의 차이를 비교 연구하고, 각 군내의 남녀군간에 치료 효과나 성장 양상에 차이가 있는지를 알아보기 위하여 시행하여 다음과 같은 결론을 얻었다. 1. Horizontal type activator를 사용한 군의 치료 전후 비교시 하악의 전방위치와 LAFH, AFH등 안면 전방부의 수직적 증가가 관찰되었다. 2. Horizontal type activator를 사용한 군의 남자군에서는 두개저에 대한 하악의 길이 증가를 동반한 상악의 후방위치가 관찰되었으며, 여자군에서는 하악의 길이 증가뿐만 아니라 하악전치의 순측 경사와 하안면 고경의 증가가 관찰되었다. 3. Vertical type activator를 사용한 군의 치료 저후 비교시 전안면고경, 전하안면고경, 후안면고경, 후하안면 고경의 증가와 함께 두 개저에 대한 하악의 길이 증가가 두드러졌다. 4. Vertical type activator를 사용한 남자군에서는 하악의 길이 증가뿐만 아니라 전안면 고경과 후안면고경의 증가가 관찰되었으나, 여자군에서는 전안면 고경의 증가만 주로 관찰되었다. 5. Horizontal type activator와 Vertical type activator를 사용한 군들의 치료 전후 비교시 치료전에는 골격적 차이를 나타내었으나 치료후에는 치성관계에서만 차이를 나타내어 서로 다른 activator의 사용이 주로 치성 성분에 대한 효과에만 차이를 나타낸다고 사료된다. 6. 치료전에는 차이가 없던 남, 여군 사이에 치료후에 차이가 나타나는 것은 치료 효과에 관계없이 남녀에 따른 성장양상의 차이가 그대로 표현된 것으로 사료된다. 연구는 거대 편도를 가진 기능성 III급 부정 교합자의 구개 편도 절제술 전후의 인두강, 설골, 두부 위치의 변화 양상에 대해 알아보기 위해 단국대학교 부속 치과 병원 교정과에 내원한 남녀 환자 42명을 대상으로 연구하여 다음과 같은 결론을 얻었다. This research was carried out to compares the treatment effects of Horizontal and Vertical type activators in Angle`s Class II div. 1 maloccusion patients with mandibular retrusion dand to find out whether different treatment effects or growth pattern were observed between sexes in each study groups. The results were as follow: 1. In horizontal activator group, forward positioning of mandible and vertical increase in anteror face as examplified by increase of LAFH and AFH were observed when pre and post-treatment datas were evaluated. 2. Males samples in Horizontal activator group showed increase in mandiular length accmpanied by posterior positioning of maxilla, whereas female samples in Horizontal activator group showed increase in mandibular body length, labial inclination of mandibular incisors and increase in lower anterior facial height. 3. In vertical activator group, increase in AFH, LAFH, PFH and LPFH were observed when pre and post treatment datas were evaluated. 4. Male samples in Vertical activator group showed increase in mandibular body length and anterior and posterior facial heights, whereas females samples of Vertical activator group showed mainly increase in anterior facial height. 5. When pre and post treatment datas of Horizontal and vertical activator groups were compared. skeletal difference were mainly observed in pretreatment datas but dental difference were observed in post treatment datas, indicating that two actiators differ only in their effects to dental variables. 6. Difference between sexes were noted after treatment although no difference were observed between sexes in each groups before treatment. This indicates that inherent growth effects in each sex exerts more influence than appliances used for treatment.

연삭가공에서 절삭유 에어로졸 측정평가에 관한 연구

황덕철,황준,우창기,정의식 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

This paper presents the experimental results to analyze the characteristics of cutting fluid aerosol generation in grinding process. Machining is a one of the broad manufacturing process to produce the parts, products and various molds and dies. The environmental impact due to aerosol generation via atomization process is a major concern associated with environmental consciousness. Experimental results show that the generated fine aerosol which particle size less than 10 micron appears near worker's breath zone under given operational conditions. The aerosol concentration is much higher enough to affect human health risk with its generated aerosol quantities. This qualitative analysis can be provided the basic knowledge for further research for environmentally conscious machining technology developments.