Hot-filament 화학기상 증착법에 의한 탄소나노튜브의 성장 및 표면 특성

최은창,김정태,박용섭,최원석,홍병유,Choi, Eun-Chang,Kim, Jung-Tae,Park, Yong-Seob,Choi, Won-Seok,Hong, Byung-You 한국진공학회 2007 Applied Science and Convergence Technology Vol.16 No.3

본 연구에서는 실리콘 웨이퍼 위에 마그네트론 스퍼터링 시스템을 이용하여 Ni 촉매 층을 증착시키고, $NH_3$와 $C_2H_2$ gas를 이용하여 탄소나노튜브를 성장시켰다. Hot-filament 플라즈마 화학기상 증착법으로 탄소나노튜브의 성장 온도는 350, 450, 550, $650^{\circ}C$로 변화시켰으며, 성장되어진 탄소나노튜브는 field emission scanning electron microscope(FESEM) 분석을 하여 관찰하였고, 접촉각 측정법을 이용하여 탄소나노튜브 층의 특성을 분석하였다. 결과적으로 성장 온도는 탄소나노튜브의 성장 특성을 변화시키는 중요한 요소이다. In this paper, the catalyst layer is deposited on silicon substrate using magnetron sputtering system and carbon nanotubes(CNTs) were grown in $NH_3\;and\; C_2H_2$ gas by hot-filament plasma enhanced chemical vapor deposition (HFPECVD) system. A growth temperature of carbon nanotubes was changed from $350^{\circ}C\;to\;650^{\circ}C\;by\;100^{\circ}C$. We observed the shape of CNTs by a field-emission scanning electron microscope(FE-SEM) measurement and analyzed the surface characteristic of CNTs layer by contact angle measurement. That is, the growth temperature of CNTs is the important factor leads to the variation of the properties.

Unexpected Pulmonary Embolism Following Microvascular Head and Neck Reconstruction : Report of Two Cases and Review of the Literature

최은창,Choi, Eun Chang The Korean Society for Head and Neck Oncology 2014 대한두경부 종양학회지 Vol.30 No.1

유리피판을 이용한 두경부 재건후 폐색전은 드물게 발생한다. 수술후 예상하기 힘들고 갑작스럽게 발생하기 때문에 환자가 아주 위험한 상황에 빠질 수 있다. 즉각적인 발견과 적절한 치료만이 환자의 생명을 구할 수 있다. 유리피판을 이용한 두경부 재건후 발생한 폐색전증 2예를 문헌고찰과 함께 보고하는 바이다.

플라즈마 밀도와 기판의 기울임 정도에 따른 탄소나노튜브의 성장

최은창,김경욱,홍병유,Choi, Eun-Chang,Kim, Kyung-Uk,Hong, Byung-You 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.7

We need to control the growth orientation of CNTs on a substrate for applications to various electric devices. Generally, the flow direction of feed gases and electric field between two electrode affect to growth orientations of CNTs. In this paper, we varied tilt degrees $(0^{\circ},\;20^{\circ},\;35^{\circ},\;50^{\circ},\;65^{\circ},\;90^{\circ})$ of substrates on a cathode and DC bias voltages (0, 500, 700 V) applied between two electrodes in order to change growth orientations of CNTs. We confirmed that tilt degrees of the substrate and variation of DC bias voltages affected to the shape and orientation of the grown CNTs on the substrate.

바이오센서로의 응용을 위한 수직 배열된 탄소나노튜브의 식각처리

최은창,박용섭,최원석,홍병유,Choi, Eun-Chang,Park, Yong-Seob,Choi, Won-Seok,Hong, Byung-You 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.7

The metal catalyst particles which there is as impurities on a tip part of carbon nanotube (CNT) are not good to apply it to a nano-electronic device. It was very important the opening of CNT-tip to fix a target bio material and a material to accept in CNT in a biosensor, so we performed $HNO_3$ wet etching to remove the metal catalyst particle which there was on a tip part of CNT grown up in the study and observed the opened CNT-tip with etching time. We synthesized the CNTs using a HF-PECVD method and choses the CNT length of 700 nm for the application of nano-electronic device such as a biosensor etc.. We observed the opened CNT-tip with wet etching times of $HNO_3$ (10, 30, 60 min). From the results, we observed that the CNT-tip was opened with the increase of wet etching time lively. In case of CNTs etched during 60 min, we confirmed that there was not the ratio of Ni included in CNTsI as catalyst. Conclusively, in the case of CNT etched for 60 minutes, it is completely good for application of a biosensor and, in addition, the metal-free CNTs will contribute to the application of other nanoelectronic devices.

구강 및 구인두암의 수술에 있어서 하악골 부분절제술에 대한 고찰

최은창(Eun Chang Choi),홍원표(Won Pyo Hong) 대한두경부종양학회 1994 대한두경부 종양학회지 Vol.10 No.2

Segmental mandibulectomy causes severe functional disability and cosmetic problem. Many methods of reconstruction have been used but none of these procedures provides the ideal solution. There has been increased interest in the possibility of preserving a portion of the mandible and still carrying out a adequate tumor resection. We experienced four cases of marginal with sagittal mandibulectomy in patients with floor of mouth. buccal. and soft palate carcinoma, and sagittal mandibulectomy in 8 patients with tonsillar carcinoma and a case of marginal mandibulectomy in tonsillar cancer patient. In all cases mandible facing the tumor were successfully resected and repair of the mandible. postoperative facial contour were satisfactory. We think. that these sagittal procedures are oncologically sound in its removal of tumor. biomechanically secure and maximize postoperative rehabilitation while maintaining the normal contour of the face.

손 최장너비 기반 손바닥 영역 검출

최은창(Eun Chang Choi),김준연(Jun Yeon Kim),이재원(Jae Won Lee),임종관(Jong Gwan Lim) 한국콘텐츠학회 2018 한국콘텐츠학회논문지 Vol.18 No.4

HCI 분야에서 대표적인 손 제스처 인식은 IT기기의 개발과 더불어 사용자와 기기 간의 상호작용 및 정보교환을 위한 방법으로 주목받고 있다. 영상 처리를 통한 손 제스처 인식에서 손바닥 영역 검출은 처리속도 및 인식률 향상에 기여하는 핵심 처리 과정이다. 본 논문에서는 손바닥 영역 검출(palm area detection)을 위해 손과 손목을 영상 분할(image segmentation) 하는 새로운 방법을 제안한다. 손의 해부학적 특성으로 가장 넓은 폭이 발생하는 엄지와 소지의 장골 간격을 손 영상의 수평 투사 히스토그램으로 계산 후 이 간격을 지름으로 하는 원을 그려 손바닥 영역을 검출한다. 이 방법의 우수성을 검증하기 위하여 다단 형판정합(multiple stage template matching)을 사용해 10가지 손 제스처에 대해 기존 방법 4가지와 인식 성능을 비교 평가한다. 손 제스처 인식에 관련한 연구가 다양하나 손바닥 영역 검출에 특화된 성능 비교 문헌이 저조함을 강조한다. In the HCI, hand gesture recognition is attracting attention as a method for interaction and information exchange between users and devices along with the development of IT devices. In hand gesture recognition through image processing, palm region detection is a key process contributing to improvement of processing speed and recognition rate. In this paper, we propose a new method for image segmentation between the hand and wrist for palm area detection. The anatomical characteristics of the hand are used to calculate the distance between the iliac bones of the thumb and little finger, which have the widest width, by the horizontal projection histogram of the hand image, and then the palm area is detected by drawing a circle having the width as the diameter. In order to verify the superiority of this method, multiple stage template matching is used to compare and evaluate recognition performance against the four conventional methods for 10 hand gestures. Note that the literatures to offer palm area detection performance evaluation are few although there are many studies on hand gesture recognition.

경부청소술 시료의 기록과 자료의 보관

최은창(Eun Chang Choi),고윤우(Yoon Woo Koh),김철호(Chui Ho Kim),김동영(Dong Young Kim) 대한두경부종양학회 2001 대한두경부 종양학회지 Vol.17 No.1

It is well established that cervical lymph node metastasis is the base of clinical study on head and neck cancer. But few studies have been reported on lymph node metastasis of head and neck cancer in Korea. We consider it essential that studies on cervical lymph node metastases are conducted on pathologically proven database. Therefore, We must have database and consitent system for documentation and data collection of neck dissection specimen for prospective and retrospective study. Herein, We suggest several points from our experiences performing the proper data collection and documentation of neck dissection specimen.

후두의 비편평상피암

최은창(Eun Chang Choi),김광문(Kwang Moon Kim),흥원표(Won Pyo Hong) 대한두경부종양학회 1990 대한두경부 종양학회지 Vol.6 No.2

Most common laryngeal cancer is squamous cell carcinoma, but various kinds of non-squamous cell tumor also occurs in the larynx. It is quite different from epidermoid carcinoma in the aspect of invasive behavior, metastatic route and treatment modality. Its proper diagnosis is somewhat difficult due to its rarity. This paper presents clinical feature of eight non-squamous cell tumor of the larynx experienced during the past 15 years.

후두 및 하인두 편평세포암종의 경부 잠재전이율

최은창(Eun Chang Choi),김동영(Dong Young Kim),고윤우(Yoon Woo Koh),홍정표(Jung Pyoe Hong),이세영(Sei Young Lee),홍원표(Won Pyo Hong) 대한두경부종양학회 1999 대한두경부 종양학회지 Vol.15 No.1

Background and Objectives: Occult neck metastasis rate of laryngeal and hypopharyngeal cancer varies widely depending upon authors. Materials and Methods: Sixty four cases, previously untreated, of N0 laryngeal and hypopharyngeal squamous cell carcinoma patients who underwent surgery as an initial treatment from 1992 to 1997 were evaluated. All had unilateral or bilateral elective neck dissection at the time of surgery for the primary. Occult neck metastasis rate was evaluated with pathologic examination of neck dissection specimen. Results: Occult neck metastasis rate by primary site was as follows. Supraglottis ipsilateral 32%(8/25) contralateral 15%(3/20), glottis ipsilateral 17%(5/30), contralateral 0%(0/22), hypopharynx ipsilateral 78%(7/9), contralateral 25%(2/8). Conclusion: Supraglottic and hypopharyngeal cancer may need elective neck treatment bilaterally. Occult neck metastasis of glottic cancer to opposite site was minimal.

유리피판 시대의 대흉근피판의 역할

최은창(Eun Chang Choi),김철호(Chul Ho Kim),김세헌(Se Heon Kim),김영호(Young Ho Kim),김광문(Kwang Moon Kim) 대한두경부종양학회 2001 대한두경부 종양학회지 Vol.17 No.2

Background and Objectives: Reliable and versatile free flap has become a mainstay in reconstruction of the head and neck. But until now pectoralis major myocutaneous flap (PMMCF) as workhorse is useful and has some advantages such as good viability, one-stage reconstruction and carotid protection. The objective of this study was to review the role and indication of PMMCF in this era of potent free flaps for head and neck reconstruction. Patients and Methods: Sixty one PMMCF and one hundred forty six free flaps used for head and neck reconstruction between 1991 and 2001 were reviewed retrospectively. We compared the applied sites of flap, the flap failure rate and complications. Results: Contrary to the free flap, use of PMMCF has gradually decreased after the middle of 1990s. PMMCF were mainly used for mucosal defect(33cases, 54.1%) and cervical skin defect(22cases, 36.1%) and free flap were mainly used for mucosal defect(129cases, 88.4%). In point of use of PMMCF according to years, from 1991 to 1997, 30cases(70%) are used to reconstruct mucosal defect and 12cases(29%) are used to reconstruct skin defect. But from 1998 to 2001, only 2cases(10.5%) are used to reconstruct mucosal defect and 13cases(68.4%) are used to reconstruct neck skin defect. In case of free flap, from 1991 to 1997, 41cases (87%) are used to reconstruct mucosal defect and from 1998 to 2001 88cases(89%) are used as same purpose. Three major necrosis (more than 50%) deveolped in 61 PMMCF (4.9%) and three major necrosis developed in 146 free flaps(2.1%). Conclusion: PMMCF is no longer flap of choice for primary reconstruction but it is a still one of a good tool in some head and neck reconstruction such as covering single wide defect of face or neck skin, back-up procedure of free flap, postoperative status, treatment of pharyngocutaneous fistula and covering vital structure.