Band Line-Up in Ordered GaInP / GaAs From Capacitance-Voltage Analysis

권용환,조용훈,최병두,박상규,정원국 대한전자공학회 1998 대한전자공학회 학술대회 Vol.1998 No.1

Fabrication of 40 Gb/s Front-End Optical Receivers Using Spot-Size Converter Integrated Waveguide Photodiodes

권용환,최병석,김제하,Joong-Seon Choe,Kisoo Kim,Kwang-Seong Choi,HoGyeong Yun 한국전자통신연구원 2005 ETRI Journal Vol.27 No.5

We fabricated 40 Gb/s front-end optical receivers using spot-size converter integrated waveguide photodiodes (SSC-WGPDs). The fabricated SSC-WGPD chips showed a high responsivity of approximately 0.8 A/W and a 3 dB bandwidth of approximately 40 GHz. A selective wetetching method was first adopted to realize the required width and depth of a tapered waveguide. Two types of electrical pre-amplifier chips were used in our study. One has higher gain and the other has a broader bandwidth. The 3 dB bandwidths of the higher gain and broader bandwidth modules were about 32 and 42 GHz, respectively. Clear 40 Gb/s non-return-to-zero (NRZ) eye diagrams showed good system applicability of these modules.

[초청논문] 100G 코히어런트 광 OFDM 핵심 광전부품 기술

권용환,김종회,윤천주,최중선,최광성,김기수,장순혁,정환석,김광준,원용욱,한상국,R. Giles,Y. K. Chen,J. Lee,N. Kaneda,X. Liu,C. Chandrasekhar,남은수 한국통신학회 2009 한국통신학회 기타 간행물 Vol.2009 No.12

ICT 기술 기반의 녹조(Algal Bloom) 모니터링 및 예측 연구

권용환 한국통신학회 2019 정보와 통신 Vol.37 No.1

본고에서는 녹조 모니터링 및 예측과 관련한 ICT기술인 인공지능 예측 기술, 직독식 수질복합센서, 초분광 영상 등의 최근 국내외 연구동향에 대해 살펴본다.

The Diagnostic Validity of the 13 C-Urea Breath Test in the Gastrectomized Patients: Single Tertiary Center Retrospective Cohort Study

권용환,김나영,이주엽,최윤진,Kichul Yoon,Hyuk Yoon,Cheol Min Shin,박영수,이동호 대한암예방학회 2014 Journal of cancer prevention Vol.19 No.4

Background:This study was conducted to evaluate the diagnostic validity of the13C-urea breath test (13C-UBT) in the remnant stomachafter partial gastrectomy for gastric cancer. Methods:The13C-UBT results after Helicobacter pylorieradication therapy was compared with the results of endoscopic biopsy-basedmethods in the patients who have received partial gastrectomy for the gastric cancer. Results:Among the gastrectomized patients who showed the positive13C-UBT results (≥ 2.5‰, n = 47) and negative13C-UBT results(< 2.5‰, n = 114) after H. pylorieradication, 26 patients (16.1%) and 4 patients (2.5%) were found to show false positive and falsenegative results based on biopsy-based methods, respectively. The sensitivity, specificity, false positive rate, and false negative rate forthe cut-off value of 2.5‰ were 84.0%, 80.9%, 19.1%, and 16.0%, respectively. The positive and negative predictive values were 44.7%and 96.5%, respectively. In the multivariate analysis, two or more H. pylorieradication therapies (odds ratio = 3.248, 95% confidenceinterval= 1.088-9.695, P= 0.035) was associated with a false positive result of the13C-UBT. Conclusions:After partial gastrectomy, a discordant result was shown in the positive13C-UBT results compared to the endoscopic biopsymethods for confirming the H. pyloristatus after eradication. Additional endoscopic biopsy-based H. pyloritests would be helpful toavoid unnecessary treatment for H. pylorieradication in these cases.

재발성 궤양성 대장염 환자에서 병발한 괴저고름피부증 2예

권용환,김재우,박소연,김문영,김현수,백순구,쟘시드 압둘 가파,조미연 대한소화기내시경학회 2010 Clinical Endoscopy Vol.41 No.5

Pyoderma gangrenosum (PG) begins with a painful, erythematous skin lesion followed by pustule formation and rapid ulceration in which an erythematous border surrounds a sterile, necrotic center. In most patients, symptoms of ulcerative colitis precede PG, and exacerbations of the bowel disease frequently correlate with worsening of the skin lesions. As PG is not commonly encountered by clinicians, the diagnosis of such lesions is not always straightforward. This case emphasizes the importance of detailed history taking and the consideration of PG as a differential diagnosis of such lesions in patients with a background of related systemic disease. The prognosis of PG is generally good. But, early aggressive therapy can minimize severe complications, and maintenance treatment may prevent some devastating consequences. We report two cases of PG that developed on the entire body and on an anterior chest wall abscess with ulcerative colitis, which improved with corticosteroid and cyclosporine. 괴저고름피부증은 통증이 있는 홍반성 구진으로 시작되어 농포를 형성하고 급격하게 진행되는 무균성, 괴사성 궤양으로 발전하는 병변이다. 대부분의 환자에서 궤양성 대장염의 증상이 선행하고 장 질환의 악화는 피부 병변의 악화와 연관성을 가진다. 괴저고름피부증은 임상의에게 드문 질환이기 때문에 진단이 바로 내려지는 경우가 적다. 이 증례는 전신 질환인 궤양성 대장염에서 피부 병변의 감별진단으로 괴저고름피부증을 고려하기 위해서 세심한 병력청취가 중요함을 보여주는 경우이다. 일반적으로 괴저고름피부증의 예후는 좋은 편이나 적극적인 조기 치료는 심각한 합병증을 최소화할 수 있고 지속적인 치료는 발생할 수 있는 후유증을 막을 수 있다. 저자들은 궤양성 대장염으로 진단받은 두 명의 환자에서 전신과 전흉부에 괴저고름피부증이 발생하여 스테로이드와 사이클로스포린 치료로 호전된 증례를 경험하여서 문헌고찰과 함께 보고한다.

콩과 천마 분말을 첨가한 국수의 품질특성

권용환,박은숙,김종권,정연신,황영현 경북대학교 농업과학기술연구소 2010 慶北大農學誌 Vol.28 No.-

To develop the functional noodles, powders of soybean and Gastrodine rhisoma were mixed with wheat powder. When 0-5% of soybean powder was mixed with wheat one, the characteristics of noodles was changed as follows; Along with the increasing of mixed soybean powder, L(brightness) and a(redness) value was decreased. Hardness showed increasement in all noodles added with soybean powder but, on the contrary, Cohesiveness was decreased. The content of isoflavones in noodles was increased along with the increament of mixing ratio of soybean powder. Sensory evaluation showed that the noodles with 5% of sobyean powder was significanly higher than those of no-soybean powder. At the same time, the characteristics of noodles added with Gastrodine rhisoma was evaluated. The results were as follows; As in soybean powder, L(brightness) and a(redness) value was decreased along with the increasing of mixed Gastrodine rhisoma. Compared with no-powder, hardness and Chewiness was significantly increased in 0.5% and 1.0% in soybean powder, and 0.5% in Gastrodine rhisoma one, respectively. Sensory evaluation showed that the noodles with 1.0% of Gastrodine rhisoma powder was significanly higher than those of no-soybean powder. Considering together with sensory evaluation and economic aspect, noodles with 5% of soybean powder and 0.5% of Gastrodine rhisoma to be the best ones. 1. 콩분말을 첨가한 국수의 품질특성 색도 - 콩분말을 첨가량이 증가할수록 L(밝기)값은 감소, a(적색도)값은 감소함. 조직감 - 경도는 콩분말을 첨가한 모든 국수에서 증가, 응집성은 감소함. 이소플라본 함량 - 콩분말 첨가량이 증가할수록 증가함. 관능평가 - 전체적인 기호도가 대조군에 비하여 3,5% 콩분말 국수가 유의적으로 높음. 2. 천마 분말을 첨가한 국수의 품질특성 색도 - 천마분말을 첨가량이 증가할수록 L(밝기)값은 감소, a(적색도)값은 감소함. 조직감 - 경도는 대조군에 비하여 0.5, 1% 천마국수에서 유의적으로 증가, 씹힘성은 0.5% 천마국수에서 유의적으로 증가함. 관능평가 - 전체적인 기호도가 대조군에 비하여 1% 천마분말 국수가 유의적으로 높음. 3. 콩, 천마 분말을 첨가한 국수의 품질특성 최종 적정혼합 비율 - 콩분말은 소비자의 기호성을 고려하여 5%로 결정함. 천마분말 - 0.5, 1%에서 품질특성에 따른 유의적 차이가 나타나지 않았으므로 상업성을 고려하여 0.5%로 결정함.

내시경 절제술 후 조직학적 음성 결과를 피하는 노하우

권용환 대한상부위장관ㆍ헬리코박터학회 2018 Korean Journal of Helicobacter Upper Gastrointesti Vol.18 No.1

Endoscopic resection (ER) is the current standard of care for selected cases of gastric epithelial dysplasia or early gastric cancer because of its curative en bloc resectability and complete histopathological assessment of the specimen. Although ER provides many advantages to surgery, some adverse events, such as bleeding, perforation, and local recurrence, can occur during and after the procedure. Furthermore, negative pathological findings after ER cause concerns about the adequacy of the procedure and local recurrence after ER among endoscopists and patients. Several variant factors, such as complete removal of small gastric tumor lesions by using initial forceps biopsy, pathological inconsistencies between pathologists, and performing ER in the wrong area. Thus, endoscopists must consider these risk factors to avoid and manage negative pathological results.

Minimally Invasive Plate Osteosynthesis of Radius-Ulna Fracture using Circular External Fixator in a Dog

권용환,강진수,조형선,이기창,김남수,김민수 한국임상수의학회 2017 한국임상수의학회지 Vol.34 No.1

Fracture stabilization techniques continue to evolve and provide approaches that minimize the iatrogenictrauma associated with surgical procedures. Minimally invasive plate osteosynthesis (MIPO) is a recently describedmethod of biological internal fixation performed by introducing a bone plate via small insertional incisions that areremote to the fracture site. Indirect reduction techniques can generally be utilized when performing MIPO. In thiscase report, we describe MIPO of a radius-ulna fracture by indirect reduction using circular external fixation foralignment and distraction in a dog.

뉴로모픽 포토닉스 기술 동향

권용환,김기수,백용순,Kwon, Y.H.,Kim, K.S.,Baek, Y.S. 한국전자통신연구원 2020 전자통신동향분석 Vol.35 No.4

The existing Von Neumann architecture places limits to data processing in AI, a booming technology. To address this issue, research is being conducted on computing architectures and artificial neural networks that simulate neurons and synapses, which are the hardware of the human brain. With high-speed, high-throughput data communication infrastructures, photonic solutions today are a mature industrial reality. In particular, due to the recent outstanding achievements of artificial neural networks, there is considerable interest in improving their speed and energy efficiency by exploiting photonic-based neuromorphic hardware instead of electronic-based hardware. This paper covers recent photonic neuromorphic studies and a classification of existing solutions (categorized into multilayer perceptrons, convolutional neural networks, spiking neural networks, and reservoir computing).