• Journal of Chest Surgery
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• 제25권10호
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• pp.1082-1086
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• 1992

Adenosquamous carcinoma of the lung is a rare disease entity and its clinical characteristics, treatment, and prognosis are poorly described. Stage I disease are amenable to operation as in bronchogenic carcinoma of non-small cell type, but stage III adenosquamous carcinoma shows highly aggressive behavior with rapid progression. We have experienced a case of stage III adenosquamous carcinoma of the lung in a 38-year-old male with a large mass in the right upper lobe with multiple metastasis in the mediastinal lymph nodes. Interestingly, all of the metastatic lymph nodes proved to be adenous component histologically. After right pneumonectomy and extensive lymph node dissection, the patient had received one cycle of chemotherapy. However, clinical signs of distant metastasis to bone and brain were discovered within 5 months postoperatively.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1417-1422
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• 2003

An electrical cascade impactor is a multistage impaction device to separate airborne particles into aerodynamic size classes using electrical method. We designed a real-time three-stage electrical low-pressure impactor, which is proper to nanometer sized environmental aerosols. Performance evaluation was carried out for stage 1 and 2. The monodisperse liquid dioctyl sebacate (DOS) particles were generated using condensation-evaporation followed by electrostatic classification using DMA (differential mobility analizer) for particles with diameters in the range of $0.04{\sim}0.8{\mu}m$. The evaluation of the electrical impactor is based on the use of two electrometers, one connected to the impaction plate of the impactor, and the other to the faraday cage as backup filter. The results showed that the experimental 50% cutoff diameters in the operation pressure were 0.53 and $0.12{\mu}m$ for stage 1 and stage 2. The effect of operation pressure on the cutoff diameter and the steepness of collection effcieicy curves is investigated.

• 한국초전도ㆍ저온공학회논문지
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• 제6권2호
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• pp.40-45
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• 2004

The experimental results of the G-M (Gifford-McMahon) type pulse tube refrigerators are presented in this paper. The pulse tube refrigerator, which has no moving parts at its cold section, is attractive in obtaining higher reliability, simpler construction, and lower vibration than any other small refrigerators. The objectives of this study are to develop the design technology of the G-M type pulse tube refrigerator and acquire its application methods for replacing G-M cryocooler. As a preliminary test, the refrigeration performances of the basic, orifice, and double inlet pulse tube refrigerators were investigated. The lowest temperature obtained in the one-stage pulse tube refrigerator was 34.4K and the refrigeration capacity at the optimum operation condition was 23W at 80K. And the lowest temperature of the second stage cold head in the two-stage pulse tube refrigerators was 18.3K and the refrigeration capacities at optimum condition were 0.45W at 20K and 20W at 80K, respectively. Finally, the lowest temperature obtained in the three-stage pulse tube refrigerator was 29.8K and the refrigeration capacity at the optimum operation condition was 1.3W for 40K and 5W for 70K.

• Journal of Chest Surgery
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• 제32권9호
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• pp.781-789
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• 1999

배경 및 목적: 폐동맥밴딩술(pulmonary artery banding)은 폐동맥밴딩에 따른 합병증과 2차 수술시의 사망률에 있어서 상당한 위험부담을 갖고 있다. 이에 본 연구에서는 폐동맥밴딩술후에 시행되는 2차 수술의 위험부담을 알아보기 위해서 이전에 폐동맥밴딩술을 받았던 소아에게 시행된 2차 완전교정술의 성적을 조사하였다. 방법: 이전에 폐동맥밴딩술을 받았던 환아들중 1988년 5월부터 1997년 6월사이에 개심술에 의한 2차 완전교정술을 받았던 29례의 소아를 대상으로 하였다. 연령은 생후 2개월에서 45개월까지 였다(평균 20.6$\pm$9.0개월). 이들중 27례는 기왕의 폐동맥밴딩술후에 심부전 증상이 호전되었던 예들이었고(정기 수술군), 2례는 그렇지 못하여 조기에 2차 수술을 시행해야 했었다(조기 수술군). 술전 진단명은 양대혈관우심실기시가 2례(양대혈관우심실기시군), 심실중격결손이 주병변이었던 경우가 27례(심실중격결손군)였었다. 결과: 폐동맥밴딩술후 2차 완전교정술 시행까지의 기간은 5일부터 45개월까지로 평균 15.5$\pm$8.7개월이었다. 수술방법은 양대혈관우심실기시 2례중 1례에서는 심실내 턴넬교정법이, 1례에서는 수정 Glenn수술이 시술되었고, 심실중격결손군에서는 전례에서 심실중격결손의 첨포봉합을 함과 아울러 누두부근육절제술 4례 및 형성부전성 폐동맥판막의 판막절제술 1례가 추가시행되었다. 2차 완전교정술시에, 18례에서는 폐동맥밴딩으로 인해 초래된 협착을 해소하기 위해서 폐동맥패취성형술을 시행하였고, 1례에서는 수정 Glenn수술을 위해 주폐동맥을 근위부에서 완전결찰하였다. 2차 완전교정술에 따른 병원사망률은 17.2%(5례)였는데, 사망원인으로는 저심박출 4례 및 자가면역 출혈성 빈혈 1례가 있었다. 본 연구에 있어서, 양대혈관우심실기시군(2례)과 조기 2차 수술군(2례)은 높은 병원사망률을 나타내는 위험인자로 작용하였다. 그리고 만기사망 1례가 있었다. 결론: 본 연구에서 이전에 폐동맥밴딩술을 받았던 소아에게 2차 완전교정술을 시행했던 결과는 폐동맥밴딩에 따른 후천적 병변을 함께 교정해야 하는 어려움에 기인하여 술후 이병률과 조기 수술사망률이 상당히 높게 나타났다. 따라서 가능하면, 단순 심실중격결손에 있어서는 1차 완전교정술이 요망된다.

• Journal of Chest Surgery
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• 제28권8호
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• pp.807-810
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• 1995

The recommended approach for dumbell trmor is a one-stage removal by a team work of both neurosurgeons & thoracic surgeons. Recently we removed a case of dumbell tumor in a 69 years old woman with standard posterolateral thoracotomy and concomitant laminectomy as single stage operation. Postoperative course was uneventful and there were no postoperative neurologic signs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.1030-1034
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• 1993

A converter topology which is capable of four-quadrant(motoring and generation) operation is proposed for the variable speed constant frequency(hereafter referred as VSCF) power conversion scheme. The new converter topology for the VSCF power conversion scheme is made of two functional stages. One is converting stage which consists of six switches and six diodes and it interfaces a three-phase 60Hz at supply and a single-phase variable-frequency ac source. The other is the commutating stage though which each phase-winding is energized.

• 한국정보기술학회논문지
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• 제16권11호
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• pp.23-34
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• 2018

본 논문에서는 고효율 고역률 LED 조명장치용 전원공급장치를 제안한다. 제안한 전원공급장치는 풀브리지 다이오드 정류기와 플라이백 컨버터로 구성된 단일단 전력구조이며, 이에 따라 하나의 제어기 IC와 하나의 전력반도체스위치만을 사용하여 역률개선과 출력전압조정을 동시에 수행한다. 또한 제안한 전원공급장치는 회생스너버를 이용하여 주스위치의 전압스트레스와 스위칭손실을 감소시키며, 동기정류기를 이용하여 시스템 효율을 향상한다. 적용된 동기정류기는 새로운 전압구동형이며 동작과 구성이 간단하다. 본 논문에서는 역률개선부와 주전력변환부의 동작분석을 통하여 제안한 전원공급장치의 동작원리를 설명하고 동기정류기의 동작에 관하여 간략하게 설명한다. 또한 40W급 프로토타입 전력회로의 설계예시를 제시하며, 설계된 회로파라미터들에 의해 제작된 프로토타입의 실험 결과를 통하여 제안한 전원공급장치의 동작특성을 입증한다.

• 대한족부족관절학회지
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• 제24권1호
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• pp.25-30
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• 2020

Purpose: Generally, the treatment of ankle trimalleolar open fractures is divided into two stages: external fixation and debridement; and secondary internal fixation. On the other hand, this two-stage operation takes considerable treatment time and is challenging in procedures requiring reduction. The purpose of this study was to evaluate the radiologic and clinical results of an immediate one-stage internal fixation operation considering the wound conditions to overcome two stage operation disadvantages. Materials and Methods: From September 2009 to January 2018, 24 cases of ankle trimalleolar open fractures, who underwent immediate internal fixation and were followed up for at least one year, were studied retrospectively. The open wound was divided into the Gustilo-Anderson classification. Open reduction and internal fixation were performed on every medial and lateral malleolar fracture. On the other hand, with posterior malleolar fractures, surgical or conservative treatment was performed depending on the fragment size. The radiologic outcome was evaluated using the Burwell and Charnley criteria and American Orthopaedic Foot and Ankle Society (AOFAS) scores, and complications, such as infection and posttraumatic arthritis, were used for the clinical evaluation. Results: The wound was classified into eight cases (33.3%) of type I, 11 cases (45.8%) of type II, and five cases (20.8%) of type IIIa. The degree of reduction was anatomical, fair, and poor in 16 cases (66.7%), six cases (25.0%), and two cases (8.3%), respectively. The mean AOFAS score was 79 points, and there were complications, such as infection in three cases (12.5%) and post-traumatic arthritis in two cases (8.3%). Conclusion: Satisfactory results were obtained through immediate surgical treatment in ankle trimalleolar open fractures of types I, II, and IIIa.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.145-150
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• 2003

The national subway went under construction in 1971, and after three years of endeavor, Seoul subway line number one opened for traffic in 1974. Line number two went under construction in 1978 and it opened for traffic in 1984. With the use of safety operation for more than 20 years, the life cycle nearly came to an end. Therefore the improvements for the safety operation are unavoidable. The total system should not be affected when the new and conventional systems are overlapped, the system operation is in the initial stage, and it confronts the situation of abnormal operation. However, there is a total lack of experience in construction and improvement for the trains that are in the use of large transport and density headway. In this paper, we propose an improvement method of the subway signalling system using ATO (Automatic Train Operation control scheme) to which the latest Digital ATC is applied, and examine the first application model of ATO system.

• Journal of Chest Surgery
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• 제20권3호
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• pp.473-482
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• 1987

The records of 65 patients with a confirmed diagnosis of primary lung cancer who underwent surgical therapy at the Department of Thoracic and Cardiovascular Surgery of the Keimyung University Hospital were analyzed during the period of 8 years and 4 months, from August, 1978 to December, 1986. The peak incidence was observed in the 5th decade of life and the mean age was 52.9 years old. Male versus female ratio was 8.3:1 Cough was the most frequent presenting symptom, 76.9% then chest discomfort, hemoptysis and dyspnea followed in order. 44.6% of the patient had 2 months of prediagnostic symptomatic period, 72.3% had 5 months, and the mean was 5.7 months. As for preoperative diagnosis, 62 of total 65 patients revealed the mass lesion on simple chest x-ray, and 56 of 65 patients on bronchoscopic biopsy, 10 of 37 patients on sputum cytology and 15 of 15 patients on computerized tomography of the chest were positive. Of the 65 patients, 35 [53.9%] had squamous cell carcinoma, 18 [27.7%] adenocarcinoma, 3 [4.6%] large cell carcinoma, and 3 [4.6%] small cell carcinoma all which was oat cell carcinoma. 83.1% of the total patient was resectable, and 34 underwent pneumonectomy and 20 lobectomy. Of these 65 operations, 29 was radical resection, 25 palliative, and 11 exploratory thoracotomy. As for clinical stagings, 23 patients were in Stage, I, another 23 in Stage II and 19 in Stage III, while 16 was in stage, I, 14 in stage ll and 35 in stage III in postoperative staging evaluation. In correlation of postoperative TNM classification and radical resection, those patients who had lung cancer of stage I [14/16] and stage II [9/13] had more radical resection. As postoperative complications, one patient had massive bleeding, two empyema, one empyema with bronchopulmonary fistula, and one cardiac herniation. Operative mortality rate was 1.5% [1 patient]. Mean duration between 1st operation and discovering recurrence in 18 patients was 12.7 months.