판상형 충전제의 함량과 배향에 따른 PP복합체의 영률 변화 연구

서상범(Sang Bum Seo),이용현(Yong Hyun Lee),정선경(Sun Kyoung Jeong),이승구(Seung Goo Lee),이기윤(Kee Yoon Lee) 한국고분자학회 2012 폴리머 Vol.36 No.2

이 논문은 판상형 충전제의 함량과 배향에 따라 폴리프로필렌 복합체의 영률 변화에 미치는 영향을 연구 하였다. 이론적인 예측은 Lee와 그의 연구자들에 의해 제안된 두 개의 종횡비, ρα=a1/a3과 ρβ=a1/a2 를 이용하여 3차원 타원체의 형상을 계산하였고 실험값과 비교 분석하였다. 판상형 충전제로 운모와 탈크를 사용하였다. 충전제의 형태는 SEM을 이용해 관찰하였고, 종횡비는 고분자의 흐름을 기준으로 좌표축을 설정하여 통계적 방법으로 계 산하였다. 충전제가 운모인 경우에 ρα=13.5와 ρβ=1.8이었고, 탈크의 경우는 ρα=3.8과 ρβ=1.4이었다. 또한 충전제 의 2개의 종횡비와 함량이 기계적 물성에 미치는 영향을 실험적으로 연구하였다. 운모의 경우 30 wt% 함량일 때 E11이 약 2.7배 향상되었다. 탈크의 경우는 E11이 약 2.3배 향상하였다. This paper studied the effects of the content and the orientation of the disk shape fillers on the modulus of PP composites. The experimental results were compared with the theoretical calculations which included the three dimensional ellipsoids and analyzed by two aspect ratios, ρα=a1/a3 and ρβ=a1/a2 proposed by Lee and his researchers. Mica and talc were used as disk shape fillers in the composites. The shapes of mica and talc were observed by SEM and aspect ratios were statistically calculated. For the case of mica, the average aspect ratios were ρα=13.5 and ρβ=1.8, and for the case of talc, they were ρα=3.8 and ρβ=1.4. Also, the effects of two aspect ratios and the content of filler on the mechanical properties were studied: For 30 wt% of mica, E11 increased up to about 2.7 times, and for the other case of talc, E11 increased up to about 2.3 times, respectively.

JMX기반 클러스터에서의 효율적 스케줄링

李基哲,蔡熙星 弘益大學校 科學技術硏究所 2004 科學技術硏究論文集 Vol.15 No.-

With new Java technologies like J2ME, J2EE, JMX, Jini and JDMK, the necessity of integrating existing Java-based system functionalities arose. Moreover, with the advances of the technologies related to application servers, the use of EJB technology based application servers increased rapidly. Recently, the demand of supporting on-line multimedia contents which have multiple terabytes size data increases. To address this problem, a clustering technology which interconnects multiple computers with moderate price range has been proposed as an alternative to a single, high performance high price server. In this paper, through experiments, the adaptive characteristic and load balancing effects are presented. Our scheduling scheme has been experimented and compared with conventional methods. The experiments show promising results, opening the possibility of using clustered Java-based systems for general purposes. Our system proves to adapt to various situations and balance its load effectively.

출판 디자인용 한글 본문체의 폰토그래피에 관한 연구

李起盛 혜전대학 1999 出版文化硏究所論文集 Vol.1 No.-

齒科嬌正用線材의 物理的 性質에 미치는 熱處理의 影響

李基大,權五源,成材鉉 慶北大學校 齒科大學 1985 慶北齒大論文集 Vol.2 No.1

The physical properties of .016" orthodontic wires by heat treatment were studied in tension, bending, hardness and microstructures. The wires were tested in the as-manufactured and heat-treated conditions. The results were as follows: Ultimate tensile strength and yield strength were slightly increased by heat treatment, but Elgiloy was the most effective by geat treatment. The strength of Elgiloy showed the highest value after heat treatment above 6 minutes at 500, 600℃. Also, bending fluxure modulus of elasticity were progressively increased by heat treatment. the hardness number of Australian of as-manufactured wires showed the highest value, and Elgiloy showed the highest value by heat treatment. Microstructure of as-manufactured wires showed fibrous interlocking grains, and a coarse grains after heat treatment and an austenite structure after solution heat treatment.

사립체 DNA 뉴클레오타이드 3243 A→G 돌연변이 [MTTL1^*MELAS3243G]에 의한 MELAS 증후군

박기형,김승현,이영주,김희태,김주한,김명호,박성섭 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

糞便檢査에 있어서 세로판 厚層塗抹法과 簡易食鹽水浮游法의 比較檢討

李駿商,張基浩,朱炅煥,金洙鎭,林漢鍾 고려대학교 의과대학 1979 고려대 의대 잡지 Vol.16 No.1

Experiments had been made to evaluate more efficient method in stool examination for various helminth ova. Authors examined 2,016 nationwidely collected stool specimens by the two methods, cellophane thick smear method and brine floatation method. The results were as foliows; 1. Of 2,019 specimens examined by cellophane thick smear method, the positive rates of following helminth ova were; Ascaris lumbricoides (fertilized) 27.3% Ascaris lumbricoides (unfertilized) 13.6%, Trichuris trichiura 39.0%, Hookworm 0.1%, Enterobius vermicularis 0.05% Hymenolepis nana 0.04%, Taenla spp. 1.3% Clonorchis sinensis 1.1% and Metagonimus yokogawai 5.7%. And, A. lumbricoides (fertilized) 27.0%, A. lumbricoides (unfertilized) 3.8%, T. trichiura 38.1%, Hookworm 2.0%, Trichostrongylus orlentalis 0.6%, E. vermicularis 0.2%, H. nana 0.8%, and M. yokogawai 0.05% by brine floatation method. 2. The causes of inferior positive rates in some helminth ova by cellophane thick smear method were shortly discussed and suggest some opinions in improvement of detection ability. 3. The positive rates of following helminth ova were superior in cellophane thick smear method to those of brine floatation method: A. lumbricoides(fertilized), Taenia spp., C. sinensis and M. yokogawai. And, the positive rates of following helminth ova were superior in brine floatation method: Hookworm T. orientalis, H. nana and E. vermicularis. 4. Cellophane thick smear method has been known to be one of the most effective methods in mass stool examination. But, this method is not so effective in detection of certain species of helminth ova. Therefore, employment of brine floatation method added to cellophane thick smear method is desirable for the better result of mass stool examination.

친환경건축물 인증기준의 분류체계 비교 연구

이승민,박상동,신기식,최무혁 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

Energy problem of our country is very serious and the energy import is being increased continuously. To solve the problems related to energy and environment, many countries including our country have prepared and carried out various certification programs to disseminate environmentally friendly buildings. The purpose of this study is to investigate the basics and category systems of domestic green building certification criteria and to utilize it as reference materials for developing integrated criteria applicable to all buildings.

점진성과 직교성에 기반한 은닉 유닛을 이용한 학습기능 강화

李基哲,蔡熙星 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

The number of attributes of real world data are sometimes too high for any data mining technique to be applied directly. The removal of redundant and unnecessary attributes is very essential to improve the efficiency of data mining systems. A novel method is proposed here, which substantially reduces the dimensionality of data by incrementally and orthogonally adding attributes in back-propagation networks. Basically, a new attribute is found in the form of a weight vector between a new hidden unit and the input layer. The weight vector of a new hidden unit is learned and orthogonally rotated until maximum orthogonality is obtained, and incrementally added. The experiments show that our method substantially reduces the dimensions of real world data, and still the resulting transformed data can be used to produce rules (or a system) which exhibit higher recognition rates.

NAP 공정을 이용한 하수의 질소 및 인 제거에 관한 연구

이성기,송영일,김현중,진성기 조선대학교 환경공해연구소 2000 環境公害硏究 Vol.16 No.1

In the process of NAP(Nightsoil Application Process)to get rid of organism, nitrogen and phosphorus, the retention time in an aerobic tank is set up 4hr, 5hr and 6hr with Al, A2 and A3 reactor the sludge return rate is 50% and the internal return rate is 200%. The change of DO, PH, MLSS, MLVSS, Alkalinity, SBOD, SCOD, Organism, SS, Nutrients and the removal rate of those conditions are followed as below. The removal rate of BOD in each reactor is 81.9% in A1, 83.9% in A2 and 87.2% in A3. The average removal rate of COD is 82.3% in A1, 83.6% in A2 and 88.0% in A3. The average removal rate of SS is 81.9% in A1, 83.9% in A2 and 87.2% in A3. The results show that A3 reactor, which has longer retention time than others in the aerobic tank has better removal rate of organism and SS. The average removal rate of T-N in each reactor is 51.4% in A1, 51.8% in A2 and 60.3% in A3. The average removal rate of T-P is 43.4% in A1, 46.0% in A2 and 52.78% in A3. It indicates that the removal rate is higher when the retention time in the aerobic tank is increased. NAP process can be operated that inserting nightsoil which causes to increase C/N in a reactor affects microorganism activity and increases the removal rate of nutrients in the spite of the decrease of the retention time. If the reactor conditions which are internal return rate, return sludge rate and volume of inserting nightsoil are set up properly, The removal rate can be higher in NAP process than in DNR process in which nightsoil is not inserted.

담배 박각시나방 Manduca sexta의 계획된 세포죽음동안의 Proteasome의 변화

이구봉,우기민,조만희,이상한,장예진,김창세 순천향의학연구소 2000 Journal of Soonchunhyang Medical Science Vol.6 No.2

모든 진핵세포의 주요 단백질 분해요소인 proteasome은 변성되거나 상해된 불필요한 단백질을 제거할 뿐만 아니라, 세포주기를 비롯한 다양한 대사과정들의 주요 효소들을 필요 시 적절히 분해함으로써 항상성을 유지시키는 필수적인 효소로 잘 알려져 있다. 또한 proteasome은 특정 포유동물 조직의 계획된 세포죽음(programmed cell death 또는 apoptosis)와 밀접하게 관련되어 있다고 보고된 바, 본 연구에서는 담배 박각시나방(Manduca sexta)의 변태과정에서 일어나는 마디간 근육(intersegmental muscle)의 급격한 파괴과정동안의 proteasome의 변화양상을 발현 및 단백질 분해활성을 중점으로 조사하였다. 정상근육과 파괴직전의 근육으로부터 proteasome을 분석한 결과 단백질 분해활성이 최소한 6배 이상 증가하였으며, proteasome의 주요 구성성분들의 발현 변화를 각각의 항체(antibody)를 이용하여 조사한 결과 세포죽음 직전에 급격히 증가함을 보였다. 이러한 구성성분들의 발현증가가 proteasome 복합체 형성을 통해 활성의 증가를 일으키는지 조사한 결과, 세포내에서 실질적으로 단백질 분해활성을 담당한다고 여겨지는 26S proteasome(2,000 kDa)의 위치에서 커다란 활성의 변화와 구성성분의 증가를 볼 수 있었다. 따라서, 담배 박각시나방의 계획된 세포죽음 현상은 특정 호르몬의 신호에 의해 proteasome의 발현이 급격히 증가하여 26S proteasome의 복합체 형태로 세포 내 대부분의 단백질들을 분해함으로써 30시간이내 근육조직을 완전히 소멸시키는 것을 알 수 있었다. 한편, proteasome을 구성하는 특정 구성성분의 과다 발현이 세포의 단백질 분해현상에 어떠한 영향을 미치는 지 조사하기 위하여 쥐의 fibroblast cell에 26S proteasome의 ATPase 구성성분인 m56 유전자를 삽입한 후 세포의 추출물로부터 proteasome의 양과 활성의 변화를 관찰하였다. Proteasome을 초원심분리로 추출하여 관찰한 결과, 담배 박각시나방의 경우와는 달리 유전자 삽입 세포는 모든 실험에서 정상 세포와 전혀 차이를 보이지 않았다. 이 결과로부터 세포의 생명 유지에 필수적이고 매우 다양한 기능을 가진 proteasome은 40여개의 구성성분들의 발현이 매우 정교하게 조절되고 있으며, 특정 세포죽음 자극(apoptotic signal)이 왔을 때 일련의 구성 성분들의 발현과 26S proteasome 복합체 형성이 증가함으로써 그 기능을 수행하는 것을 알 수 있으며, 보다 자세한 연구는 비정상적 단백질 분해나 세포죽음을 동반하는 여러 질환들의 원인과 현상을 규명할 수 있으며, 또한 그 활성을 조절함으로써 궁극적인 치료의 방향도 제시 가능할 것으로 기대된다.