Control of Wildlife Rabies in North America : Ontario 주를 중심으로

조한철 한국수의공중보건학회 1995 예방수의학회지 Vol.19 No.2

Application of Analytic Solution in Relative Motion to Spacecraft Formation Flying in Elliptic Orbit

조한철,박상영,최규홍 한국우주과학회 2008 Journal of Astronomy and Space Sciences Vol.25 No.3

The current paper presents application of a new analytic solution in general relative motion to spacecraft formation flying in an elliptic orbit. The calculus of variations is used to analytically find optimal trajectories and controls for the given problem. The inverse of the fundamental matrix associated with the dynamic equations is not required for the solution in the current study. It is verified that the optimal thrust vector is a function of the fundamental matrix of the given state equations. The cost function and the state vector during the reconfiguration can be analytically obtained as well. The results predict the form of optimal solutions in advance without having to solve the problem. Numerical simulation shows the brevity and the accuracy of the general analytic solutions developed in the current paper.

Experimental analysis of lithium niobate CMP for room temperature bonding

조한철,Sukhoon Jeong,Jaehong Park,Hojun Lee,Jiheon Oh,Hyoungjae Kim,Haedo Jeong 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

Lithium niobate (LN, LiNbO3) is a type of artificial crystal exhibition piezoelectricity, pyroelectric and ferroelectricity, which has been widely used in electronic components. To use in electronic components, a LN wafer has to be bonded to a Si substrate. Bonding of Si and LN allows for ease of micromachining a high quality electrically-sensitive thin film, as well as creating mechanically-rigid diaphragms. For this reason, Si combined with LN is desirable for microelectromechanical system (MEMS) devices such as a pressure sensors, microfluidic devices and optical data storage systems. However, the large difference in thermal expansion coefficient between Si and LN causes serious thermal stresses during the thermal-pressure bonding process which has generally been used. Therefore room temperature bonding would be the best candidate for making a strong and stress-free interface between Si and LN. Room temperature bonding requires a lower surface roughness and lower defect contact on the LN wafer surface than thermal bonding does. A chemical mechanical polishing (CMP) process produces a thin LN wafer with a high quality surface suited for room temperature bonding and with a suitale thickness that affects the sensitivity of the devices. Here LN wafers were polished using a colloidal silica slurry, resulting in a high material removal rate (MRR) and a fine surface quality under a condition of low pH, high abrasive concentration and low flow rate. The polishing mechanism of LN was investigated by mechanical, chemical and thermal analysis.

Post-CMP Cleaning에서 PVA 브러시 오염이 세정 효율에 미치는 영향

조한철,유민종,김석주,정해도,Cho, Han-Chul,Yuh, Min-Jong,Kim, Suk-Joo,Jeong, Hae-Do 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.2

PVA (polyvinyl alcohol) brush cleaning method is a typical cleaning method for semiconductor cleaning process especially post-CMP cleaning. PVA brush contacts with the wafer surface and abrasive particle, generating the contact rotational torque of the brush, which is the removal mechanism. The brush rotational torque can overcome theoretically the adhesion force generated between the abrasive particle and wafer by zeta potential. However, after CMP (chemical mechanical polishing) process, many particles remained on the wafer because the brush was contaminated in previous post-CMP cleaning step. The abrasive particle on the brush redeposits to the wafer. The level of the brush contamination increased according to the cleaning run time. After cleaning the brush, the level of wafer contamination dramatically decreased. Therefore, the brush cleanliness effect on the cleaning performance and it is important for the brush to be maintained clearly.

추적 기간에 따른 유방암 생존자들의 디스트레스와 삶의 질

조한철,김의태,민준원 한국유방암학회 2016 Journal of Breast Disease Vol.4 No.2

Purpose: Few studies have reported postdiagnosis differences in distress and quality of life (QOL) for breast cancer (BC) survivors. Here we investigated the differences in distress and QOL for BC survivors in Korea, during follow-up. Methods: Completed questionnaires were collected from 179 BC survivors in 2013. Functional Assessment of Cancer Therapy-Breast was administered to measure the distress and Distress Thermometer and Problem List was administered to measure the QOL. Results: The mean QOL score was 96.69 (standard deviation, ±20.33). Seventy-nine patients (44.1%) with distress-test scores >4 were assigned to the severe distress group. The patient group with higher family income had high QOL score (p=0.008). In addition, QOL scores were significantly higher in patients who lived longer after diagnosis (p=0.016). Patients at high TNM stage had low QOL scores (p=0.006). Furthermore, older patients tended to have high distress scores (p=0.028). Based on duration of the postdiagnosis period, we divided the patients into two groups. Seventy patients had a postdiagnosis period <2 years; 109 patients, postdiagnosis period ≥2 years. Distress score of the under-2-year group (4.26±2.73) was significantly higher (p=0.044) than that of the longer-than-2-year group (3.47±2.42). Conclusion: BC survivors showed improvement in physical well-being, emotional well-being, and functional well-being domain of QOL over time. However, social well-being and BC subscale score were only slightly improved over time. It is possible that cancer patients’ supporting programs are focused on the recently diagnosed patients or those currently undergoing treatment. Therefore, more support should be made available to long-term BC survivors.

A Study on Relationship between Defense Industry’s Management Performance and Defense Export Promotion Activities

조한철,최석철 한국방위산업학회 2014 韓國防衛産業學會誌 Vol.21 No.4

The South Korean defense industry is facing difficulties in ensuring its economy of scale. This is mainly because of the low demand compared to the supply. Such imbalance is on account of the unique nature of defense products, whose sole consumers are governments. Therefore, defense companies should expand their defense product sales through active PR (public relations) activities, including exhibitions, weapon systems demonstrations, and gathering information on the global defense industry. The results of this study show a positive correlation between the advertising cost and the management performance (sales and exports) of defense companies. In conclusion, defense companies can improve their management performance through active PR activities for the export of defense products.

방산 수출체계 개선방안 연구

조한철 한국방위산업진흥회 2015 國防과 技術 Vol.- No.435

광견병 예방백신 발달사

조한철 한국예방수의학회 1988 예방수의학회지 Vol.12 No.1

방산업체간 협력의 긍정적 효과에 관한 연구 -R&D 투자 효율성과 상관관계를 중심으로-

조한철 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.11

Owing to the recent revitalization of defense exports, K-Defense is facing new opportunities, domestic defense companies must first secure competitiveness to continue the current upward trend. As weapon systems are being advanced, it is necessary to secure international competitiveness through continuous investment in defense R&D. On the other hand, efforts to increase investment efficiency are needed because of the limited budget that can be invested in R&D. Cooperation between companies within the defense industry network can be an effective way of increasing the R&D efficiency by sharing knowledge, information, and resources related to technology development. Accordingly, the correlation between network centrality (level of cooperation) and the R&D efficiency of defense companies was analyzed. The analysis showed that the network centrality positively affects the R&D efficiency of defense companies. Therefore, In this study, based on the analysis results, it is necessary to strengthen the cooperation between defense companies.

동물(動物)의 Salmonella속균(屬菌) 분포(分布)에 관(關)한 연구(硏究) 제(第)1보(報) 대구지역(大邱地域)의 견(犬)에 있어서의 Salmonella 속균(屬菌)의 분포(分布)

조한철,Jo, Han-Cheol 대한수의학회 1961 大韓獸醫學會誌 Vol.1 No.1

동물(動物)의 Paratyphoid의 원인균(原因菌)으로서 각종동물(各種動物)에서 여러학자(學者)들에 의(依)하여 많은 Salmonella속균(屬菌)이 분리보고(分離報告)되고 있으나 우리나라에서는 아직 동물(動物)에 있어서 Salmonella속균(屬菌)에 대(對)한 관심(關心)이 극(極)히 희박(稀薄)하여 돈(豚)의 Paratyphoid와 추백리(雛白痢)를 제외(除外)한 그 외(外)의 가축(家畜)의 Salmonella증(症)은 거이 간과(看過)되고 있는 상태(狀態)에 있으며 인간(人間)의 Paratyphoid 및 식중독등(食中毒等)에 밀접(密接) 관계(關係)가 있음을 생각할 때 가축(家畜)의 Salmonella증(症)은 단지 수의학(獸醫學) 뿐만 아니라 공중위생상(公衆衛生上) 경시(輕視)못할 문제(問題)이다. 특(特)히 견(犬)은 애완용(愛玩用), 수렵용(狩獵用), 또는 가정(家庭) 경비용등(警備用等)으로 인간생활(人間生活)에 있어 접촉(接觸)하는 기회(機會)가 가장 많은 동물(動物)이므로 이로 인(因)한 인간(人間)의 폐해(幣害)을 생각하지 않을수 없다. 필자(筆者)는 견(犬)에 있어서의 Salmonella속균(屬菌)의 분포상태(分布狀態)를 조사(調査)할 목적(目的)으로 1958년(年) 하계(夏季) 대구(大邱) 시내(市內) 광견병(狂犬病) 예방접종시(豫防接種時) 가정상양견(家庭飼養犬) 100두(頭)의 분변(奮便)을 검사(檢査)하여 6두(頭)에서 Salmonella속균(屬菌) 각(各) 1주(株)씩을 분리(分離)하였으며 다음과 같이 균형(菌型)을 결정(決定)하였다. Sal. typhi-murium 1주(株) Sal. cholerae-suis 1주(株) Sal. paratyphi A 1주(株) Sal. bartord 1주(株) 균형미결정(菌型未決定) 2주(株) (경북대학교(慶北大學校) 논문집(論文集) 제3집(第三輯)에 발표(發表)하였음).