메조기공의 실리카-티타니아 코겔의 제조와 자율적 조습 및 광촉매 특성

이상화,곽중협,서태수,김효중,김동표 한국공업화학회 2003 공업화학 Vol.14 No.3

수용액상의 졸겔반응에 의해 메조기공의 실리카-티타니아 코겔을 제조하고 이들의 자율적 조습력과 광촉매 특성에 대해 검토하였다. 실리카-티타니아 코겔에 있어 조습력과 관계되는 세공크기와 용적은 본 연구에서 고안된역적정법에 의해 Ph 7부근 및 SiO_2/TiO_2 비가 상대적으로 큰 9/1인 경우에 가장 큰 생성물이 얻어졌다. 폐놀 분해율에 의한 광촉매 특성은 동일조건에서 SiO_2/TiO_2 비가 감소함에 따라 증가하였고, SiO_2/TiO_2 비가 9/1에서 세공크기 4.0~6.0 nm 및 세공용적 0.6~0.8 mL/g 범위로 제어된 코겔의 경우 환경습도 40~70% 범위에서 흡습량 25%, 방습량 45%로서 종래 조습재료 보다 자율조습력이 큰 것을 볼 수 있었고, 같은 조성의 실리카-티타니아 혼합 산화물과의 폐놀 분해율에 의한 광촉매 특성 비교에서도 우수한 물성을 보이고 있었는데 이것은 Ti-O-Si 결합형성으로 인해 코겔 구조내에 음전하 과잉으로 인한 활성점(브렌스테드 산점) 발현에 기인된 것으로 고찰된다. Silica-titania cogel materials have been prepared by aqueous sol-gel process using a back titration technique designed for this study. The humidity self-control and photocatalytic properties of the materials have been also investigated. In these silica-titania cogel materials, relatively large pore size and pore volume than can give a good humidity control ability are desired, and they were synthesized under the reaction condition at pH of 7 and SiO_2/TiO_2 ratio of 9/1. The photocatalytic property, which was measured by the decomposition ratio of phenol, increased with the decrease of SiO_2/TiO_2 ratio in the composition. The cogel at the SiO_2/TiO_2 ratio of 9/1, resulted in the pore size of 4.0~6.0 nm and the pore volume of 0.6~0.8mL/g. At the relative humidity range of 40~70%, the amounts of moisture absorption and desorption were 25% 45%, respectively, and these had a better humidity control ability than conventional ones. In addition, the cogel showed a superior photocatalytic property compared to that of silica and titania mixture with the same composition. This enhancement is probably due to the revelation of active sites by the excess negative charges that were induced by Ti-O-Si bond formation in the cogel structure.

구개부에 발생한 다형성선종의 치험례

이창진,김태열,김효언,김희광,전인성,윤규호 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.2

Pleomorphic adenoma is the most common of all salivary gland tumors, constituting over 50 per cent of all cases of tumors, and approximately 90 per cent of all benign salivary gland tumors. Since the term mixed tumor' was introduced by Broca for its dual origin of epithelial and mesenchymal elements, the term plemorphic adenoma suggested by Willis characterizes closely the unusual histologic pattern of the lesion. The parotid gland is the most common site but it may occur in any of the salivary glands. It is somewhat more frequent in women and in the fourth to sixth decades, but they are also relatively common in young adult and have been known to occur in children. Treatment of choice is surgical excision. Adequate surgery with safe margin reduce its recurrence rate. We represent a case of pleomorphic adenoma with literature review in 65-year old male occured in the palate. The lesion was successfully treated by surgical excision.

Flux법에 의한 PZN-PNN-PT-PZ계 세라믹스의 제조 및 압전특성

이기태,남효덕 嶺南大學校工業技術硏究所 1992 연구보고 Vol.20 No.2

The quarternary system ceramics 0.5[xPb(Zn1/3Nb2/3)O3-(1-x)Pb(Zn1/3Nb2/3)O3-0.5[yPbTiO3-(1-Y)Pb-ZRO3] were prepared by flux method and compared their piezoelectric properties with conventional method. Piezoelectric properties of sample prepared by flux method were improved compared to that of conventional method. By adding PZN, morpholropic phase boundary of the sample shifted to more Zr-rich composition and showed a drop in piezoelectric properties.

正規 槪接觸 計量多樣體의 C-holomorphically 射影變換에 關하여

李孝泰 慶一大學校 1990 論文集 Vol.6 No.1

本 論文은 CHP-曲率텐서가 平坦할 條件을 求하며 特히 CHP變換에 대한 再歸多樣體의 性質을 硏究함.

고령 장애인의 일(WORK) 경험과 욕구에 관한 연구 : 뇌병변 장애를 중심으로

이효성,김근아,김태연,오정은 한국장애인고용촉진공단 고용개발원 2007 장애와 고용 Vol.17 No.2

본 연구의 목적은 고령이면서 장애를 동시에 경험하고 있는 고령 장애인들의 일 경험과 욕구에 관한 특성을 당사자의 관점에서 이해하는 것이다. 이러한 목적을 달성하기 위해 50세 이상 뇌병변장애인 13명을 대상으로 일 경험과 욕구에 관한 개방형식의 질문으로 심층 인터뷰를 실시하여 그 결과를 분석함으로써 고령 장애인 당사자의 일 경험과 욕구에 대한 심층적 이해와 현상의 의미를 깊이 있게 파악하고자 하였다. 분석결과, 고령 뇌병변장애인들은 일을 하고자 하는 높은 욕구를 가지고 있으며 일을 통해 삶의 의미와 보람을 찾고자 하나 현실적으로는 장애와 고령, 그리고 만성질환자라는 삼중고 속에서 “일하기” 에 상당한 제약을 받는 것으로 나타났다. 이러한 연구결과는 지금까지 고용정책에서 소외되었던 고령 장애인의 ‘일’ 에 관한 정책적 개입의 필요성을 강력하게 시사해 주고 있다. The purpose of this study is to understand the characteristics of the experiences and needs for work of aged people with disabilities who experience both old age and disability from their viewpoint. To this end, this study conducted in-depth interviews with 13 people aged 50 or older with encephalopathic disabilities by open-ended questions regarding their experiences and needs for work, and analyzed the results so as to more deeply understand the experiences and needs for work of aged people with disabilities as well as the implications of the present situation. The analysis results showed that aged people with disabilities have high needs for work and try to find the meaning and worth of life through work, but in reality face considerable limitations to ‘working’ in the triple handicaps of disability, old age, and chronic disease. The results of this study strongly suggest the need for policy intervention in the ‘work’ of aged people with disabilities who have been neglected by employment policies until now.

소결체 Scrap으로부터 Co 회수

이종대,이종욱,박노국,박영효,이태진 영남대학교 공업기술연구소 2001 工業技術硏究所論文集 Vol.29 No.1

The recovery of Cobalt(Co) and Tungsten Carbide(WC) from refractory scrap using electrolysis in an acid solution is studied. The method of electrochemical decomposition is a simple and economical process. The most important factor in the process of electrochemical decomposition is the component and concentration of electrolyte. The results show that the decomposition yield in sulfuric acid is better than other acid. This method is applicable for industrial process, because the decomposition yield is increased as scrap weight.

WO_3의 환원-탄화에 있어서 Zeolite NaX, HX, KX의 특성에 따른 영향

이동활,이종대,박영효,박노국,이태진 한국공업화학회 2003 응용화학 Vol.7 No.1

The effect of the Zeolite HX,NaX, and KH prepared by ion-exchange method, on the reduction-carburization of WO_3 was studied This study was performed at thetemperature range from 300℃ to 735 ℃ with CO gas. The produced gas, CO_2, was analyzed by mass spectroscopt The addition of the Zeolite HX, NaX,and KX into WO_3 increased the efficiency of the reduction-carburization of WO_3 and Zeolite HX with the strongest acidity was the most effective on redution-carburization among them. The Zeolite HX, NaX, and KX improved the oxygen mobility of WO_3 and the acidity of the Zeolite was directly related to the increasing efficiency of reduction-carbuization of WO_3.

DCT를 이용한 정지화상의 효과적인 DC계수의 부호화

이성필,김태효 慶南大學校 附設 工業技術硏究所 1993 硏究論文集 Vol.11 No.-

최근 JPEG(Joint Photograph Expert Group)이 변환부호화기술을 이용한 정지화상의 부호화 알고리즘을 국제표준의 권고안으로 내 놓았다. JPEG시스템에서는 현재 블럭의 DC계수를 예측하기 위해 이전블럭의 DC계수를 사용하여 간단한 1-D 예측기를 이용한 DPCM(Differencial Pulse Coded Modulation)으로 부호화된다. 본 논문에서는 블럭엣지차분(Block Edge Difference, BED)예측기가 기본 JPEG시스템의 성능을 개선하기 위해 제안되었다. BED예측기는 현재블럭의 DC계수를 예측하기 위해 인접하고 있는 블럭들 사이의 엣지차분정보를 이용한다. 제안된 BED예측기가 JPEG예측기보다 DC계수를 더욱 효과적으로 부호화할 수 있음을 확인하기 위해 통계적 모델에 의한 분산해석을 하였고, 또 실제화상을 이용한 컴퓨터 시뮬레이션에서 제안된 BED예측기를 사용했을 때 기본 JPEG예측기보다 약 5% 이상의 비트율(bit-rate)의 압축효과를 얻을 수 있었다. Recently, an international standard, JPEG algorithm is proposed for still image coding using the technique of discrete cosine transform(DCT). In JPEG scheme, in other to predict the DC coefficient of current block, the DC coefficient of the previous block is used by a simple 1-D predictor of DPCM. In this paper, a block edge difference(BED) predictor is proposed to improve the performance of the basic JPEG system. The BED predictor uses the block edge difference between adjacent blocks for prediction of the current block. A statistical variance analysis shows that the BED predictor can encode the DC coefficients more effectively than the JPEG predictor. Computer simulation using real test images also shows that when the proposed BED predictor is used, it is obtained about 5% bit-rate compression over the basic JPEG predictor.

대한민국 자동차 번호판에서 블록 이진화 기법을 이용한 문자 인식 기법

장인태, 이슬기, 우효정, 안재형 충북대학교 컴퓨터정보통신연구소 2012 컴퓨터정보통신연구 Vol.20 No.1

In this paper, the image binarization method using standard specifications of the vehicle license plate to recognize characters on the plates is proposed. The global binarization method that had a threshold over entire image pixels cannot acuratelly binarize in case that local average brightness are varied to each plates characters regions. The proposed method uses the characters regions in the standard specifications of the korean vehicle license plates as binarization blocks. For installed cameras on national roads and parking areas, the computer simulation results showed average characters recognition rate about 5% higher than the otzu global binarization method.

기본 소생술 e-러닝(e-Learning) 멀티미디어 컨텐츠 개발 연구

이영아,김태민,김효식,고재문 한국응급구조학회 2002 한국응급구조학회지 Vol.6 No.1

This study was designed to develop e-Learnig multimedia contents to provide the first aid rescuer with the basic resuscitation members of the public, corporations and any other institutions who wish to learn this skills. It is carried out from October to December in 2001. This program was constructed on the basic of the network-instructional system Design model, this model has several progressive steps, which includes the planning, analysis of the contents, development of the contents, instructional design, development of web-based and multimedia, pilot test, implement, and evaluation. The URL of this site is http://www.cyber.hc.ac.kr named as the cyber education program for the basic resuscitatingskill. This contents consisted of 8 chapters providing as follows : Introduction, anatomy and physiology of heart-ling. Adult Cardio-Pulmonary Resuscitation. Adult Foreign-body Air-Obstruction. Child Cardio-Pulmonary Resuscitation, Foreign-body Air-Obstruction. To make the learning more interesting, as much animation and videos were integrated. In conclusion, this e-Learning multimedia contents will be useful for student as well as members of the public. It significantly increases the chances of saving the life of person who has collapsed.