증례 : 식도암 환자에서 혈관 내 스텐트 삽입으로 치료한 대동맥 식도 누공 1예

윤경한 ( Kyung Han Yoon ),장재영 ( Jae Young Jang ),오신주 ( Shin Ju Oh ),박유민 ( Yoo Min Park ),정명화 ( Myoung Hwa Jung ),김정욱 ( Jung Wook Kim ),장영운 ( Young Woon Chang ) 대한내과학회 2015 대한내과학회지 Vol.88 No.2

Hemorrhage into the esophagus due to aortoesophageal communication is very rare but life-threatening with high morbidity and mortality. Because of this, most cases of aortoesophageal fistula are confirmed by autopsy. However, we report herein a case of a 62-year-old male with an aortoesophageal fistula who was successfully treated with endovascular stent-grafting. The patient had undergone esophageal stent insertion due to esophageal cancer and experienced hematemesis and hemodynamic shock due to an aortoesophageal fistula. Emergency endoscopy was unable to identify the source of the hemorrhage due to massive bleeding. Computed tomography of the chest revealed a focal pseudoaneurysm at the descending aorta and diffuse thinning of the esophageal wall, which were treated with endovascular stent-grafting. Although aortoesophageal fistulas are usually fatal, implantation of a covered stent into the esophagus may help prevent massive bleeding, providing valuable time to treat the patient. (Korean J Med 2015;88:182-186)

항행 및 항법 : 첨단운전자보조시스템용 이동객체검출을 위한 광학흐름추정기의 설계 및 구현

윤경한 ( Kyung-han Yoon ),정용철 ( Yong-chul Jung ),조재찬 ( Jae-chan Cho ),정윤호 ( Yun Ho Jung ) 한국항행학회 2015 韓國航行學會論文誌 Vol.19 No.6

본 논문에서는 첨단 운전자 보조 시스템 (ADAS; advanced driver assistance system) 용 이동객체검출 (MOD; moving objectdetection)을 위한 광학흐름추정기 (OFE; optical flow estimator) 의 하드웨어 구조 설계 결과를 제시하였다. 광학흐름추정 알고리즘은 차량 환경에서 높은 정확도를 나타내는 광역 최적화 (global optimization) 기반 Brox 알고리즘을 적용하였다. Brox 알고리즘의 에너지 범함수 (energy functional)를 최소화 하는 과정에서 생성되는 Euler-Lagrange 방정식을 풀기 위해 하드웨어 구현에 용이한 Cholesky factorization이 적용되었으며, 메모리 접근율 (memory access rate)를 줄이기 위해 시프트 레지스터 뱅크 (shift registerbank)를 도입하였다. 하드웨어 구현은 Verilog-HDL을 사용하였으며, FPGA 기반 설계 및 검증이 수행되었다. 제안된 광학흐름추정기는 40.4K개의 logic slice 및 155개의 DSP48s, 11,290 Kbit의 block memory로 구현되었다. In this paper, the design and implementation results of the optical flow estimator (OFE) for moving object detection (MOD) in advanced driver assistance system (ADAS). In the proposed design, Brox’s algorithm with global optimization is considered, which shows the high performance in the vehicle environment. In addition, Cholesky factorization is applied to solve Euler-Lagrange equation in Brox’s algorithm. Also, shift register bank is incorporated to reduce memory access rate. The proposed optical flow estimator was designed with Verilog-HDL, and FPGA board was used for the real-time verification. Implementation results show that the proposed optical flow estimator includes the logic slices of 40.4K, 155 DSP48s, and block memory of 11,290Kbits.

안면부에 재발되는 환상 홍반을 보인 Sjogren 증후군

강진문 ( Jin Moon Kang ),윤경한 ( Kyeong Han Yoon ),한승경 ( Seung Kyung Hann ) 대한피부과학회 1998 대한피부과학회지 Vol.36 No.5

Sjogren's syndrome has been considered to be an autoimmune disease affecting various organs including salivary and lacrimal glands. It occurs most commonly in middle-aged women, and less than 20 cases with primary Sjogren's syndrome have been reported in children. An 11-yim-old boy presented with recurrent annular erythema on the face that had been present for 2 years. A schirmers test showed a positive result. ANA was detected at a dilution of 1:640. Anti-Ro/SSA and anti-La/SSB antibodies were also detected. On histological examination, lymphocytes were infiltrated in the periappendegeal areas as well as the papillary and reticular dernis. The skin findimg is uncommon in children, but has become a characteristic feature of childhood Sjogrens syndrome with anti-Ro and/or anti-La antibodies. (Korean J Dermatol 1998;36(S): 910-913)

수부 습진 (手部 濕疹)

이승헌(Seung Hun Lee),윤경한(Kyung Han Yoon) 한국항공우주의학협회 1995 항공우주의학회지 Vol.5 No.2

항공 통신 기술 : L-대역 디지털 항공 통신 시스템의 수신 성능 분석

천정현 ( Jeong Hyeon Cheon ),윤경한 ( Kyung Han Yoon ),장수현 ( Soo Hyun Jang ),정윤호 ( Yun Ho Jung ) 한국항행학회 2015 韓國航行學會論文誌 Vol.19 No.2

최근 항공 통신의 데이터 트래픽 증가로 인하여, 대륙 간 항공통신을 위한 L-band 대역 디지털 통신시스템인 LDACS가 제안되었다. LDACS 모델은 LDACS type-1과 LDACS type-2의 두 가지 규격으로 정의 되었으며, 향후 면밀한 검토를 바탕으로 한 가지 시스템을 선정하여 운용하기로 하였다. 이에 본 논문에서는 두 LDACS 시스템의 규격 분석과 함께 채널 환경에 따른 수신 성능을 비교 및 평가함으로써 항공 통신 시스템에의 적용 가능성을 분석하였다. 분석결과, 두 시스템 모두 airport 채널 환경에서 큰 성능 열화를 보였으나 LOS 환경의 en-route 채널의 경우에 우수한 성능을 보임을 확인할 수 있었다. 또한, en-route 환경에서 LDACS type-1과 LDACS type-2의 비교 분석 결과, LDACS type-2 대비 LDACS type-1의 수신 성능이   BER 기준 1 dB 우수함을 확인 할 수 있었으며, 이는 보다 강력한 채널 부호가 적용되었기 때문으로 판단된다. Due to the increase in the data traffic for the aeronautical communications, LDACS has been proposed to support the data link in the continental domain. LDACS is defined in two standards of LDACS type-1 and LDACS type-2, which are going to be selected through the intensive comparison. In this paper, we analyzed two types of standards and evaluated their performance for various channel models. Simulation results show that both LDACS type-1 and LDACS type-2 have a good performance in the en-route channel model, while they have a poor performance in the airport channel model. In the comparison results for LDACS type-1 and LDACS type-2, LDACS type-1 shows the better performance of 1dB than LDACS type-2 owing to the stronger channel coding technique.

증례 : 소화기 ; 구역 반사로 천공을 초래한 식도 이물 1예

이태인 ( Tae In Lee ),장재영 ( Jae Young Jang ),윤경한 ( Kyung Han Yoon ),엄유진 ( Yu Jin Um ),홍성훈 ( Seong Hun Hong ),김정욱 ( Jung Wook Kim ),장영운 ( Young Woon Chang ) 대한내과학회 2015 대한내과학회지 Vol.88 No.5

식도 내 이물은 특별한 기저 질환 없이도 흔히 일상적인식사 중의 부주의로 인하여 우발적으로 발생할 수 있다. 대부분 내시경적으로 안전하게 제거 가능하나 환자의 연령 및 상태, 이물의 종류와 크기 및 형태, 이물이 걸려있는 위치, 내시경 시술자의 경험 등에 따라 보다 충분한 진정과 시술자의 주의를 요하며 임상적으로 필요하다면 보조 기구의 사용을 적극 고려해야 한다. 최근 저자들은 불충분한 진정 및 환자의 임상적 상황에 따라 시술 중 발생한 구역 반사 이후사라진 식도 이물이 컴퓨터 단층촬영을 통해 식도 천공 소견과 함께 확인되어 수술적 치료까지 시행한 증례가 있어 문헌고찰과 함께 보고하는 바이다. Esophageal foreign bodies are a common clinical problem; they can be removed via endoscopic intervention. However, sharp foreign bodies, such as fish bones, stuck in a physiological or pathological stenosis of the esophagus can sometimes lead to esophageal perforation. This can even lead to fatal complications, such as empyema, mediastinitis, esophago-tracheal fistula, and peritonitis. Consequently, during an endoscopic procedure, special precautions and protective devices are required. Here, we report the case of a 56-year-old woman who presented with an esophageal impacted fish bone with iatrogenic esophageal perforation caused by the gag reflex during endoscopic removal. She was treated successfully with surgery and antibiotics. The case highlights the need for sufficient sedation of the patient and attention by clinicians to achieve successful treatment without complications. (Korean J Med 2015;88:555-559)

2개의 서로 다른 부전도로를 가진 비후성 심근병증 환자를 전극도자 절제술로 치료한 증례

오치혁 ( Chi Hyuk Oh ),김승민 ( Seung Min Kim ),신재령 ( Jae Ryung Shin ),유정선 ( Jung Sun Yoo ),윤경한 ( Kyung Han Yoon ),김진숙 ( Jin Sug Kim ),박지윤 ( Ji Yoon Park ),김슬기 ( Seul Ki Kim ),김진배 ( Jin Bae Kim ) 전북대학교 의과학연구소 2013 全北醫大論文集 Vol.37 No.1

A 41-year-old man, with WPW syndrome and a hypertrophic cardiomyopathy, was admitted for recurrent palpitation. EPS (Electrophysiological study) identified that manifested bypass tract was an innocent bystander, and another concealed bypass tract was utilized as retrograde conduction, during AVRT (atrioventricular reentrant tachycardia). The multiple accessory pathways could be localized at the right free wall and left posteroseptal area. Both of them were successfully abolished with catheter ablation. Successful catheter ablation provides an evident risk reduction, as a result of a lower incidence of AF(atrial fibrillation) and a complete removal of risk for ventricular tachyarrhythmia.

고령에서 발생한 강직성척추염 1예

김광열 ( Kwang Yeol Kim ),최지영 ( Ji Young Choi ),이민혜 ( Min Hye Lee ),이운주 ( Un Joo Lee ),변자민 ( Ja Min Byun ),김유진 ( Yu Jin Kim ),윤경한 ( Kyung Han Yoon ),황인경 ( In Kyoung Hwang ),엄유진 ( Yu Jin Um ),김진숙 ( Jin Su 전북대학교 의과학연구소 2014 全北醫大論文集 Vol.38 No.1

전 흉벽통증을 호소하던 고령의 환자가 강직성척추염으로 확인 된 LOAS의 한 예로 고령의 환자에서도 염증성 관절염의 원인으로 LOAS가 가능하며 전형적인 임상양상과는 구별되는 비전형적인 증상패턴을 보일수 있음을 나타내는 증례이다. Ankylosing spondylitis(AS) is the major subtype of an interrelated heterogeneous group of inflammatory rheumatic diseases now named spondyloarthritides. Clinical features of this group include spinal and peripheral joint oligoarthritis (predominantly of the lower limbs), enthesitis, and at times, specific organ involvement such as anterior uveitis, psoriasis, and chronic inflammatory bowel disease. Clinical onset of AS after the age of 45 years is uncommon. Late-onset AS(LOAS) is characterized by severe disease, marked elevation of laboratory measurements of inflammation, and more frequent involvement of the peripheral joints (predominantly the shoulders) and the cervical spine as compared with early-onset Late onset AS. We report a case of LOAS with atypical symptom. We described a 50-year-old patient who presented with chest wall pain mainly, marked elevation of laboratory inflammatory markers, severe disease course and was successfully treated with anti-TNF inhibitor.

A Study on Fluid Dynamic Behaviors of Fluid Film Bearings Using Finite Elements

Yoon, Kyung-Han,Choi, Myung-Jin,Oh, Taek-Yul 慶熙大學校 材料科學技術硏究所 1993 材料科學技術硏究論集 Vol.6 No.-

Fluid Film Bearing의 유막(Oil film) 압력분포를 Navier-Stoke Equation에서 유도된 Reynolds Equation을 8-node Quadrilateral Elements를 사용한 유한요소법(FEM)으로 구했다. Navior-Stoke Equation을 유체 윤할문제에 적용하기위한 Reynolds Equation의 가정과 적용범위등에 관하여 논의되었으며, 유막에 대한 FEM 공식전개와 Boundary 조건들에 대하여 설명되었다. 서로 다른 두가지의 Boundary 조건들에 대한 유막분포를 비교했으며, 유막 압력분포의 FEM 해석을 입증하기 위하여 유한 요소법에 의한 결과를 실험에 의해 측정된 유막 압력분포와 비교하였다

Candida albicans의 표면 iC3b 수용체 발현 및 혈관 내피세포에 대한 유착

이광훈,윤문수,윤경한,최현주 대한의진균학회 1996 대한의진균학회지 Vol.1 No.1

Background: The adherence of microorganisms to host tissue is an important process in the pathogenesis of fungal infection. A protein that shares antigenic and structural homology with the α-subunit of leukocyte adhesion glycoprotein CD11b/CD18, also known as iC3b receptor, Mo-1 or Mac-1, has been isolated from the surface of C. albicans. Objective: This study was done to observe the changes in the expression of iC3b receptor on C. albicans by glucose or immunosuppressive agents and to elucidate the effect of glucose and anti-iC3b receptor antibodies on adhesion between human dermal microvascular endothelial cells(HDMEC) and C. albicans. Methods: We utilized immunofluorescence study and immunofluorescent flow cytometry and the binding assay of C. albicans to cultured HDMEC in vitro and blocking assay using monoclonal antibody were performed. Results: Immunofluorescence study and immunofluorescent flow cytometric analysis demonstrated surface expression of iC3b receptor on C. albicans The expression of surface iC3b receptor on C. albicans in creased in a dose dependent manner with increasing concentrations of glucose, cyclophosphamide and prednisolone. The adherence of C. albicans to HDMEC correlated positively with glucose levels. The adherence of C. albicans to HDMEC decreased significantly by the treatment with anti-iC3b receptor antibodies. Conclusion: The results suggest that iC3b receptors should be involved in the adherence of C. albicans to vascular endothelial cells and may be involved in the pathogenesis of hematogenous candidiasis.