• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.108-111
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• 2017

정지궤도용 우주발사체에는 고성능 상단엔진이 필수적이며 높은 비추력을 가지는 다단연소사이클 엔진이 적합하다. 터보펌프, 예연소기, 연소기, 공급계 시스템으로 구성된 9톤급 다단연소사이클 엔진 시스템의 기술검증시제를 제작하여 나로우주센터 3단 엔진 연소시험설비에서 3초 지상연소시험을 수행하였다. 엔진 시스템의 시동, 점화, 연소 및 종료가 정상적으로 수행되었으며 주요 성능 변수를 평가하였다.

• Archives of Plastic Surgery
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• 제48권5호
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• pp.534-542
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• 2021

Background During the early stages of lymphedema, active physiologic surgical treatment can be applied. However, lymphedema patients often have limited knowledge and misconceptions regarding lymphedema and surgical treatment. We analyzed the correlations between lymphedema severity and surgical technique according to patients' awareness of surgical treatment for secondary upper extremity lymphedema (UEL). Methods Patients with UEL diagnosed between December 2017 and December 2019 were retrospectively evaluated. At the time of their presentation to our hospital for the treatment of lymphedema, they were administered a questionnaire about lymphedema and lymphedema surgery. Based on the results, patients were classified as being aware or unaware of surgical treatment. Lymphedema severity was classified according to the arm dermal backflow (ADB) stage and the MD Anderson Cancer Center (MDACC) stage based on indocyanine green lymphography conducted at presentation. Surgical techniques were compared between the two groups. Results Patients who were aware of surgical treatment had significantly lower initial ADB and MDACC stages (P<0.05) and more frequently underwent physiologic procedures than excisional procedures (P=0.003). Conclusions If patients are actively educated regarding surgical treatment of lymphedema, physiologic procedures may be performed during the early stages of UEL.

• Journal of Preventive Medicine and Public Health
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• 제52권3호
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• pp.179-187
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• 2019

Objectives: In the USA, certain races and ethnicities have a disproportionately higher gastric cancer burden. Selective screening might allow for earlier detection and curative resection. Among a USA-based multiracial and ethnic cohort diagnosed with non-cardia gastric cancer (NCGC), we aimed to identify factors associated with curable stage disease at diagnosis. Methods: We retrospectively identified endoscopically diagnosed and histologically confirmed cases of NCGC at Mount Sinai Hospital in New York City. Demographic, clinical, endoscopic and histologic factors, as well as grade/stage of NCGC at diagnosis were documented. The primary outcome was the frequency of curable-stage NCGC (stage 0-1a) at diagnosis in patients with versus without an endoscopy negative for malignancy prior to their index exam diagnosing NCGC. Additional factors associated with curable-stage disease at diagnosis were determined. Results: A total of 103 racially and ethnically diverse patients were included. Nearly 38% of NCGC were stage 0-Ia, 34% stage Ib-III, and 20.3% stage IV at diagnosis. A significantly higher frequency of NCGC was diagnosed in curable stages among patients who had undergone an endoscopy that was negative for malignancy prior to their index endoscopy that diagnosed NCGC, compared to patients without a negative endoscopy prior to their index exam (69.6% vs. 28.6%, p=0.003). A prior negative endoscopy was associated with 94.0% higher likelihood of diagnosing curable-stage NCGC (p=0.003). No other factors analyzed were associated with curablestage NCGC at diagnosis. Conclusions: Endoscopic screening and surveillance in select high-risk populations might increase diagnoses of curable-stage NCGC. These findings warrant confirmation in larger, prospective studies.

• 소성∙가공
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• 제4권1호
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• pp.59-69
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• 1995

A simple kinematically admissible velocity field is proposed to determine the final-stage extrusion load and the average extruded length in the square-die forward extrusion of regular polygonal-shaped bars from circular billets. From the proposed velocity field, the upper-bound extrusion load and the average extruded length are determined by minimizing the total power consumption with respect to four parameters. Experiments have been carried out with hard solder billets at room temperature. The theoretical predictions of the extrusion load are in good agreements with the experimental results and there is generally reason able agreement in average extruded length between theory and experiment.

• 한국방재학회 논문집
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• 제3권3호
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• pp.165-171
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• 2003

2002년 태풍 루사의 집중호우로 금강 중상류에 위치한 초강천 유역에 막대한 홍수피해와 범람을 동반하였다. 발생한 홍수는 초강천 하류에 위치한 송천교에 부설되어 있는 송천 수위국을 잠식하여 붕괴시킬 정도로 엄청난 유량 규모를 가졌기 때문에 직접 측정할 수 없었다. 이에 본 연구에서는 매닝의 등류 공식을 이용하여 홍수량을 산정함과 더불어 적정한 조도계수를 제시하였다.

• 한국수산과학회지
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• 제46권6호
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• pp.970-972
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• 2013

We examined the relative growth of Microstomus achne during early life stages of laboratory-reared larvae and juveniles. Turning points in the relative growth of preanal length and upper jaw length against total length occurred during the settlement period (11.12-19.91 mm in total length). However, turning points in the relative growth of head length and eye diameter, as compared to total length, occurred during metamorphosis (17.57-22.47 mm in total length). Our results suggest that Microstomus achne concentrates its energy on the feeding apparatus (jaw) and digestive organs (intestine) rather than sensory or neural organs (eye, head) during early larval stage growth.

• 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.

• 자원환경지질
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• 제20권4호
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• pp.213-221
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• 1987

The Donghae mine locates at Jangjoari, Koseongun, Kyongsang-nam-do. The geology of the mine consists of the upper part of Chin dong Formation conformably overlain by tuffaceous Koseong Formation. These formations are intruded by the granodiorite and the basic dikes. The ore mineralization occurs in the fault breccia pipe at the center of a granodiorite stock. The estimated dimension of the breccia pipe is $7m{\times}70m{\times}200m$. The host rock has distinctive hydrothermal alteration halos consisting hematite zone, chlorite zone, epidote zone and sericite zone from outer zone to the ore vein. The ore mineralization occurred in the three distinctive stages. The ore minerals formed in the first stage are pyrite, sphalerite, chalcopyrite, stannite and tetrahedrite. Galena and arsenopyrite are formed in the second stage. Some sphalerite grains include exsolution dots of the chalcopyrite. It is suggested that the ore mineralization occurred by a boiling of a hydrothermal fluid during its initial stage and subsequent cooling and $CO_2$ fugacity drop of remaining hydrothermal fluid by a ground water mixing aided vertical zoning of the ore minerals.

• 대한수학교육학회지:수학교육학연구
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• 제22권4호
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• pp.619-636
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• 2012

본 연구의 목적은 학년에 따라 수학영재학급 학생들이 패턴 일반화 과정에서 사용하는 전략의 차이와 일반화 표현 방법을 알아보는 것이다. 연구를 위해 단위학교 영재학급 4~6학년 30명을 대상으로 도형과 관련한 4개의 과제에 대한 해결 전략을 살펴보았다. 연구결과, 일반화를 시작하는 단계의 문항에서 학생들은 패턴의 앞 뒤 수를 이용하여 문제를 해결하는 순환적인 관계인식 전략으로 문제를 해결하는 경우가 많았고 일반화를 형성하는 단계의 문항에서는 학년이 높아질수록 주어진 정보로 규칙이나 식을 만들어 해결하려는 상황적 인식 전략을 사용한다는 것을 알 수 있었다. 그러나 난이수준이 높은 문항일수록 학생들은 그리거나 뛰어 세기 등의 구체화를 통한 인식 전략이나 순환적인 관계 인식 전략을 선호하는 경향이 있었다. 일반화를 명확하게 하는 단계의 문항에서 학생들은 패턴을 언어로 기술하는 경향이 많았으며 높은 학년일수록 패턴을 대수적 표현(기호 또는 수식)으로 기술하려고 하였다. 정당화 단계의 문항에서 학년이 높을수록 일반화된 식으로 표현하는 비율이 높았다. 연구 결과를 통해 패턴을 찾는 과제에서 영재학급 학생들이 일반화를 하기 위한 전략의 차이를 알고 지도하는데 도움을 줄 수 있는 시사점을 제공하고자 한다.

• Journal of Chest Surgery
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• 제28권2호
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• pp.170-176
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• 1995

Fourty nine patients out of 127 esophageal cancer were managed surgically from January 1986 to December 1991, at the Department of Thoracic and Cardiovascular Surgery, Jeonbuk National University Hospital. Most frequent preoperative symptom was dysphagia and its mean duration was 3.1 months. In histopathologic examination, squamous cell carcinomas were 44 cases [89.8% , and adenocarcinomas 5 [10.2% . The tumor location were the upper esophagus in 6.1%, middle esophagus in 57.2%, lower and cardiac portion of stomach in 36.7%. Involved and metastatic organs, which were detected perioperatively, were celiac lymph nodes in 6 cases, aorta 2, stomach 2, pericardium 2, cervical lymph node 1. The esophagus was resected radically, and the procedures for esophageal replacement were performed with esophagogastrostomy in 45 cases, esophagocologastrostomy 3, and esophagojejunostomy 1. Postoperative complications occurred in 16 cases [hospital morbidity = 32.6% ,anastomotic leak 3, anastomotic stricture 2, respiratory insufficiency 2, hemoperitoneum 1, chylothorax 1, intussusception 1, empyema 1, non-A,non-B hepatitis 1, and mediastinitis 1. Hospital deaths were experienced 3 cases [ hospital mortality = 6.1% . The 6 month, one, two, and five year actuarial survival rates were 85.7%, 71.4%, 57.1%, and 27.9%, respectively. One year survival rates of stages were 100% in stage I, 90.9% in stage IIa, 63.6% in stage IIb, 25.0% in stage III, and 7.2% in stage IV.