Synthesis and Characterization of Poly(arylene ether)s Containing Benzoxazole Pendants from Novel Aromatic Difluoride Monomer

김지형,방상우,김영준,Kim, Ji Hyeong,Bang, Sang U,Kim, Yeong Jun Korean Chemical Society 2000 Bulletin of the Korean Chemical Society Vol.21 No.9

A study was done on the synthesis of new poly(arylene ether)s and poly(arylenesulfide) with rigid benzoxazole pendants using nucleophilic aromatic substitution reaction. As a new aromatic monomer, 1,4-bis(2-benzox-azolyl)-2,5-difluorobenzene [I] w as synthesized in three steps starting from 1,4-dibromo-2,5-difluorobenzene. A model reaction of difluoro monomer [I] with two equivalents of m-cresol or thiophenol in a typical ether con-densation reaction conditions gave very high yields ( > 93%) of the desired disubstituted product, suggesting the feasibility of polymer formation in these reaction system. Monomer[I] was polymerized with bisphenols and bisbenzenethiol in NMP using K2CO3 as base. The molecular weight of the resulting polymers, however,seemed relatively low according to their solution viscosity values ( ηinh = 0.15-0.29 dL/g). The poly(arylene ether)s were soluble in several common organic solvents including chloroform, pyridine and N,N'-dimethylfor-mamide. The poly(arylene sulfide) was, however, ony soluble in strong acids like sulfuric acid and trifluoro-acetic acid. The glass transition temperatures were found to be 175-215 $^{\circ}C.$ These polymers were stable up to 380-420 $^{\circ}C$ in both nitrogen and air, as determined by the temperature that a significant weight loss began to appear on TGA.

업계기고 - 화성탐사선의 카메라 렌즈 설계

김지형,Kim, Ji-Hyeong 한국광학기기산업협회 2012 光學世界 Vol.142 No.-

17세기부터 시작된 인류의 화성탐사 역사는 광학 망원경의 발달과 함께 점점 발전하기 시작하면서 21세기에 이르러 마침내 화성에 무인 탐사선을 보내게 된다. 본고는 2012년 8월 성공적으로 화성에 착륙한 화성 탐사로봇 'Curiosity(큐리오시티)'에 탑재된 17개 카메라에 대한 설명과, 2004년 화성 탐사로봇에 탑재되었던 'Opportunity(오퍼튜니티)', 'Spirit(스피릿)'의 카메라 렌즈 설계에 대한 것으로 2006년 SPIE 출판사에서 출간한 'Camera Lenses FromBox Camera to Digital'의 발췌문으로 구성되어 있다. 미항공우주국(NASA)은 이들 카메라의 렌즈 설계를 위해 ZEMAX 광학설계 소프트웨어를 사용했으며, 국내에서도 많은 광학 설계 엔지니어들이 ZEMAX를 사용하고 있다. 멀지 않은 미래에 대한민국의 광학설계 기술이 우주탐사 역사에 한획을 그을 수 있기를 기대해 본다.

임상 연구 : 간경변 환자의 신기능 평가에서 Cystatin C의 유용성에 대한 연구

김지형 ( Ji Hyeong Kim ),신동원 ( Dong Won Shin ),이설희 ( Sul Hee Yi ),최문한 ( Moon Han Choi ),최종효 ( Jong Hyo Choi ),김대용 ( Dae Yong Kim ),박무용 ( Moo Yong Park ),최수정 ( Soo Jeong Choi ),김상균 ( Sang Gyune Kim ),김진국 대한신장학회 2008 Kidney Research and Clinical Practice Vol.27 No.6

목적: Cystatin C는 사구체 기저막을 자유로이 통과하여 세뇨관에서 재흡수 완전 분해되어 사구체 여과율 (glomerular filtration rate; GFR)을 노인, 간경변 환자처럼 근육 위축을 동반한 환자에서 creatinine 보다 정확하고 민감하게 반영하는 것으로 알려져 있다. 이에 저자들은 간경변증 환자에서 cystatin C를 근거로 하는 신기능 평가의 유용성을 연구하였다. 방법: 2007년 2월부터 9월까지 순천향대학교 부천병원에 입원한 안정된 간경변 환자를 대상으로 혈청 creatinine (MDRD와 Cockroft & Gault 공식), 24시간 소변 검사, 혈청 cystatin C (Hoek와 Larsson 공식)로 측정한 GFR 값을 크롬-EDTA로 측정한 GFR를 기준으로 비교하고, 신기능을 조사하였다. 결과: 총 46명의 환자 중 Child classification A가 10명, B가 17명, C가 19명이고, 평균 creatinine 1.1±0.56 mg/dL이며, 평균 cystatin C는 1.2±0.5 mg/L이었다. 평균 GFR은 크롬-EDTA로 67.8±29.4 mL/min/1.73m2이었다. MDRD 공식으로 81.6±29.6 mL/min/1.73m2, C&G로 79.9±29.3 mL/min/1.73m2, 24시간 소변의 Cr 배설율로 62.7±29.8 mL/min/1.73m2, Hoek 공식으로 77.0±28.6 mL/min/1.73m2, Larsson 공식으로 80.0±35.2 mL/min/1.73m2 이었다. Cystatin C는 당뇨, 연령, 성별에 따라 차이가 없었다. Cystatin C는 BUN (r=0.422), MDRD 공식 (r=-0.715), C&G 공식 (r=-0.659), 24시간 소변의 Cr 청소율 (r=-0.536), 크롬-EDTA 결과 (r=-0.617)의 GFR과 의미있는 상관 관계를 보였으며, MELD score, 혈청 albumin, Creatinine, PT, bilirubin과는 관련이 없었다. Cystatin C을 이용한 Hoek 공식 (r=0.657)과 Larsson 공식 (r=0.647)의 GFR은 MDRD (r=0.550)와 C&G 공식 (r=0.458)에 비해 크롬-EDTA와 높은 상관 관계를 보였다. Cystatin C의 크롬-EDTA GFR에 대한 회귀방정식은 -33.7×cystatin C+106.4 mL/min 이었다. 신기능의 차이는 없으나, cystatin C는 모든 간경병증 환자에게서 상관관계가 높았다. 결론: Cystatin C는 간경변증 환자에게서 혈청 Creatinine보다 정확하게 신기능을 반영하고, 간경변증 정도에 관계없이 상관관계가 높았다. Purpose: Cystatin C is known to predict the glomerular filtration rate (GFR) more precisely in patients with substantial muscle atrophy, such as liver cirrhosis, compared to creatinine. We evaluated the usefulness of cystatin C for prediction of renal function in liver cirrhosis patients. Methods: From February 2007 to September 2007, we evaluated the renal function in patients with liver cirrhosis who were admitted to Soonchunhyang University Bucheon Hospital. We compared renal function with GFR as estimated by creatinine (Modification of diet in renal diseases; MDRD, the Cockroft&Gault equation; C&G, Creatinine clearance; CCr) and cystatin C (the Hoek and Larsson equations) with that of the GFR as calculated by Cr-EDTA. Results: A total of 46 patients were enrolled. The mean GFR was 67.8±29.4, 81.6±29.6, 79.9±29.3, 62.7±29.8, 77.0±28.6, 81.0±35.2 mL/min/1.73m2 according to Cr-EDTA, MDRD, C&G, CCr, Hoek and Larsson equations, respectively. Cystatin C showed a correlation to MDRD (r=-0.715), C&G (r=-0.659), CCr (r=-0.536) and Cr-EDTA GFR (r=-0.617). GFR by the Hoek (r=0.657) and the Larsson (r=0.647) equation using cystatin C showed a higher correlation with Cr-EDTA GFR than GFR by MDRD (r=0.550) and C&G equation (r=0.458). Conclusion: Cystatin C is a more accurate predictor of renal function than creatinine in patients with liver cirrhosis.

이미지 마케팅과 파사드의 관계성에 관한 연구

김지형(Kim, Ji-Hyeong) 한국실내디자인학회 2009 한국실내디자인학회 학술대회논문집 Vol.11 No.2

If the brand image is the ‘mind’ of a company, then cafe Facade’s design would be the ‘face’. Facade makes various faces and expression of its brand to distinguish itself from other competitors, and draws attention. Therefore, Facade with the good design increases competitiveness of products or service. As one of the brand image marketing, characteristics of Facade design are very important factors because they are the cafe’s first image. Facade in the commercial space is initially seen by customers so that it gives strong impression. In conclusion, Facade is the symbolic part of a shop. Therefore, the basic concept of the shop and product image should be reflected in Facade design, and it also should strong impression in order to appeal to customers. This study aims to prepare the foundation for planning cafe Facade’s design by analyzing how to express image marketing to the Facade considering the design available to be expressed in Facade as one of marketing methods, and examining the relations between image marketing and Facade.

민주화운동세대별 분단극복론의 추이

김지형(Kim Ji-hyeong) 한국역사연구회 2010 역사와 현실 Vol.- No.77

After the collapse of the Yi Seung Man regime, the April 19th Generation proceeded with active discussions regarding the Korean peninsula's unification, and they also engaged themselves in vibrant movements toward unification. Students with progressive aspiration and tendencies argued that unification should be accomplished with a neutralization of the Korean peninsula, and they demanded that the negotiation between South and North be initiated as well. They also arranged negotiation gatherings between the students of the South and North, but their efforts were thwarted with the Coup on May 16th. The June 3rd Generation based their actions upon a strong anti-Japanese Nationalist sentiment, and failed to display a distinct position regarding the resolution of the Korean peninsula's status of division. Anti-Japanese efforts were always present at the crux of the issues at the time, and it was hard to pursue them while also pursuing unification. The generation of 'Youths and Students dedicated to the cause of Democratization,' which was also very much against the 4th Republic and its 'Renewed Constitution,' concentrated upon dismantling the egregious dictatorship of the Park Jeong Hi regime and therefore achieving a democratic society. They believed that the South-North talks held during the Park regime were nothing but a sham that would only serve the regime's agenda aiming for either a prolonged or permanent ruling of the country. Efforts to resolve the peninsula's division were pursued only unofficially by factions undisclosed, which also led to the People Revolution Party incident. After experiencing the massacre that was perpetrated in Gwangju, the generation which was involved in the democratization movements of the 1980s started to display an anti-U.S. stance, and with the people who were involved in the June Democratic Struggle, movements aiming for unification and also having a better understanding of the North Korean society literally exploded. Yet at the same time, their perception of the peninsula's division showed various perspectives within as well. After the Cold war ended, their views of the peninsula's division, North Korea, and the issue of Unification, diverged into many variations.

한국어 교육에서의 한자 교수법 -비한자권 외국인 학습자를 중심으로

김지형 ( Kim Ji Hyeong ) 국제어문학회 2003 국제어문 Vol.27 No.-

재사용성을 고려한 무기체계 통합시험시스템 교전통제 모델 설계 구조

김지형(Kim Ji Hyeong),김인한(Kim In Han),김찬수(Kim Chan Su),이상태(Lee Sang Tae) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2

상변화물질PCM을 이용한 소방배관의 동파방지에 관한 연구

김영해(Young Hae Kim),김해빈(Hae Bin Kim),김동규(Dong Gyu Kim),김민수(Min Soo Kim),김지형(Ji Hyeong Kim),김회률(Hoi Youl Kim),금종수(Jong Soo Kum) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

This study is intended to prevent of the freezing of fire piping when it is exposed to a certain temperature or below by unsing the properties of PCM that is absorbing or discharging latent heat by phase changing at the certain temperature. It verified PCM’s prevention effect of freeze through numerical analysis and measrement.

소화슬러지의 비저항계수(SRF)와 모세관흡입시간(CST)의 상호관계식 유도 및 비교

김지형(Khim, Jee-Hyeong),나승민(Na, Seung-Min),박지호(Park, Ji-Ho),김영욱(Kim, Young-Uk) 한국산학기술학회 2007 한국산학기술학회논문지 Vol.8 No.4

CST와 SRF는 슬러지 탈수효율 인자로 가장 널리 사용되고 있다. 이러한 CST와 SRF는 각각의 분석특정의 장 · 단점으로 인해 실험방법 및 결과 해석시, 슬러지 탈수의 최적조건을 찾아 예측하는데 어려움이 있다. 따라서 본 연구는 탈수성 지표로 이용되는 CST와 SRF의 이론식 가운데 CST와 SRF의 상호관계식을 유도하여 각각의 실측값과 예측값을 비교한 후 비교적 측정이 간편한 CST시험만으로도 탈수최적조건을 도출할 수 있는 이론식을 검토하였다. Capillary Suction Time(CST) and Specific Resistance to Filtration(SRF) were commonly used to evaluate the sludge dewatering behaviors. A coupled equation was developed through the mathematical theory which represented both CST and SRF as the physical filterability of the ultrasonically treated sludge. The model for coupling CST and SRF includes both equipment variables and variables related to sludge characteristics, and verified with the results from experiments. The results of the theoretical and experimental study showed that a good correlation relationship among dewaterability indices.

초음파로 처리된 소화슬러지의 비저항계수(SRF)와 모세관흡입시간(CST)을 이용한 탈수특성 비교

김영욱(Kim, Young-Uk),김지형(Khim, Jee-Hyeong),나승민(Na, Seung-Min),박지호(Park Ji Ho) 한국산학기술학회 2007 한국산학기술학회 학술대회 Vol.- No.-

We investigated the effect of ultrasound on the dewaterability of sewage sludge. Because, dewatering and disposal of waste sludge is a major economical factor in the operation of wastewater treatment plants. Capillary Suction Time(CST) and Specific Resistance to Filtration (SRF) were used to evaluate the sludge dewatering behaviors. From the results of the experiment, it was found that ultrasonic treatment can improve the dewaterability. We discovered that CST and SRF were highly related, according to the correlation coefficient(R²).