• 대한기계학회논문집A
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• 제26권6호
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• pp.1194-1202
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• 2002

A study on the topology optimization of a multi-spectral camera for space-use is presented. The optimization is carried out under self-weight and polishing pressure loading. A multi-spectral camera for space-use experiences degradation of optical image in the space, which can not be detected on the optical test bench on the earth. An optical surface deformation of a primary mirror, which is a principal component of the camera system, is an important factor affecting the optical performance of the whole camera system. In this study, topology optimization of the primary mirror of the camera is presented. As an objective function, a measure of Strehl ratio is used. Total mass of the primary mirror is given as a constraint to the optimization problem. The sensitivities of the objective function and constraint are calculated by direct differentiation method. Optimization procedure is carried out by an optimality criteria method. For the light-weight primary mirror design, a three dimensional model is treated. As a preliminary example, topology optimization considering a self-weight loading is treated. In the second example, the polishing pressure is also included as a loading in the topology optimization of the mirror. Results of the optimized design topology for the mirror with various mass constraints are presented.

• 한국음향학회지
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• 제22권4호
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• pp.250-260
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• 2003

수중에서 기포는 비선형성이 강한 음향 산란체로서 수중 기포들로부터 산란된 음파들은 강한 비선형 음향특성을 보인다. 입사 음파의 산란된 음파들은 기본 주파수에서뿐만 아니라 배진동 또는 고차진동 주파수들에서도 관측된다. 서로 다른 주파수의 두 음파가 기포에 입사되는 경우, 산란된 음파들은 입사 음파들의 합 및 차주파수에서도 관측될 수 있다. 본 연구에서는 수중에 형성된 기포막에 두 음파가 입사되는 경우, 기포의 비선형성에 의해 차주파수 음파의 진폭이 증폭되고 두 입사 음파의 전파방향으로 지향성이 나타남을 관측하였다. 산란된 차주파수 음파의 지향성은 일차 음원의 지향성을 사용하여 가상음원에 대한 결맞음 산란특성으로 해석하였다.

• Journal of Gastric Cancer
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• 제17권2호
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• pp.180-185
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• 2017

Despite the decreasing incidence and mortality from gastric cancer, it remains a major health problem worldwide. Ninety percent of cases are adenocarcinomas. Here, we report a case of gastric adenocarcinoma developed after successful treatment of prior primary gastric diffuse large B-cell lymphoma (DLBCL). Our patient was an elderly man with primary gastric DLBCL in whom complete remission was achieved after R-CHOP (cyclophosphamide, adriamycin, vincristine, prednisolone plus rituximab) chemotherapy. Helicobacter pylori infection persisted despite adequate treatment leading to sustained chronic gastritis. The mean time to diagnose metachronous gastric carcinoma was seven years. We believe that a combination of many risk factors, of which chronic H. pylori infection the most important, led to the development of gastric carcinoma following primary gastric lymphoma. In summary, patients who have been successfully treated for primary gastric lymphoma should be followed up at regular short intervals. H. pylori infection should be diagnosed promptly and treated aggressively.

• Journal of Astronomy and Space Sciences
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• 제31권3호
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• pp.199-204
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• 2014

This paper intends to highlight the effect of the third-body in an inclined orbit on a spacecraft orbiting the primary mass. To achieve this goal, a new origin of coordinate is introduced in the primary and the X-axis toward the node of the spacecraft. The disturbing function is expanded up to the second order using Legendre polynomials. A double-averaged analytical model is exploited to produce the evolutions of mean orbital elements as smooth curves.

• 대한물리의학회지
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• 제11권2호
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• pp.103-114
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• 2016

PURPOSE: The purpose of this study was first to develop a Korean version of pediatric functional muscle testing for children with a motor developmental disorder who have a communication problem and who are aged below five years, and also to verify the content validity. METHODS: First, the preliminary study was conducted to verify the reliability of pediatric functional muscle testing, developed by Venita in Korea. Based on the results of the study, the primary evaluation items were selected and modified. Second, the first test of content validity was conducted through a panel discussion, and a second investigation of content validity was carried out by utilizing the Item Content Validity Index (I-CVI). In this study, we selected only 0.78 or more items from I-CVI. RESULTS: Based on the results of the preliminary study, 19 primary evaluation items were selected. Based on the results of the first and second content validity tests, 15 tertiary evaluation items for the Korean version of pediatric functional muscle testing were determined. CONCLUSION: This study developed a new Korean version of pediatric functional muscle testing and suggested that it will be a useful tool to measure muscle strength for Korean children with a motor developmental disorder and a communication problem, aged below five years.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1145-1148
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• 2014

Background: Single pegylated liposomal doxorubicin (PLD) is commonly used as a salvage treatment in platinum-resistant ovarian cancer, fallopian tube cancer and primary peritoneal adenocarcinoma (PPA) with a satisfactory outcome. However, the data for second generation PLD administered in this setting are still limited. We conducted a retrospective study to evaluate the outcome of patients who received single-agent second generation PLD (LIPO-DOX) after the development of clinical platinum resistance. The study period was between March 2008 and March 2013. LIPO-DOX was administered intravenously 40 $mg/m^2$ every 28 days until disease progression, but for not more than six cycles. The response rate was evaluated using the Gynecologic Cancer Intergroup (GCIG) criteria while the toxicity was evaluated according to WHO criteria. Twenty-nine patients met the inclusion criteria in the study period with an overall response rate of 13.8%. The median progression free survival and overall survival were three and eleven months, respectively. With the total of 96 cycles of chemotherapy, the patients developed grades 3 and 4 hematologic toxicity as follows: anemia, 0%, leukopenia, 9.6%, neutropenia, 32.3% and thrombocytopenia, 0%. In conclusion, the single agent second generation PLD demonstrated modest efficacy in patients with platinum-resistant ovarian cancer, fallopian tube cancer and PPA without serious toxicity.

• Asian Pacific Journal of Cancer Prevention
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• 제15권22호
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• pp.9831-9834
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• 2014

Background: The prevalence of esophageal cancer (EC) with second primary cancers (SPC) is increasing worldwide. This study was aimed to understand the clinical features of EC patients with SPC in the Taiwanese population. Materials and Methods: Clinical and laboratory data for 180 EC patients with or without SPC were collected between January 2009 and December 2013. Information on treatment approaches, location of SPCs and ABO blood type were also collected and stratified. Results: The most common SPC in EC patients was hypopharyngeal cancer, followed by laryngeal cancer and hepatocellular carcinoma in our study. Malignancies of colon, prostate and lung were also found. There was a significant higher portion of blood type A in the EC patients with SPC compared with those without (42.4% vs 19.5%, P=0.006). Conclusions: The frequency and SPC site distribution and blood type A should be considered in clinical evaluation of EC patients with a high risk of developing SPC in the Taiwanese population.

• 대한지구과학교육학회지
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• 제14권1호
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• pp.69-79
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• 2021

이 연구는 지구과학 예비교사와 초등 예비교사들이 과학 교과독서를 통해 과학도서와 독서에 대해 어떠한 의미를 부여하고 과학 교과독서 과정에서 과학교육에 대한 생각이 어떻게 반영되는지 비교하는 데 목적이 있었다. 연구를 위해 우리나라 중부지방에 위치한 교사 양성 대학에 다니는 지구과학교육을 전공하는 3학년 학생 24명과 초등교육을 전공하는 2학년 학생 25명을 연구대상으로 선정하였다. 연구결과, 첫째, 지구과학 예비교사들은 교과독서를 과학 내용 지식을 습득하는데 많이 활용하였으나, 초등 예비교사들은 수업에 활용하기 위한 목적과 과학적인 흥미, 궁금증 해결을 위한 것으로 이용하고 있었다. 둘째, 지구과학 예비교사와 초등 예비교사들은 과학 관련 도서를 과학 교육에 활용하는 데에서도 생각 차이를 보이고 있었다. 지구과학 예비교사들이 과학도서를 수업에 활용하는 것에 대해 드물게 서술한 반면, 초등 예비교사들은 과학수업에 대해 적극적으로 서술하였다. 셋째, 과학 교과독서 관점에서 지구과학 예비교사들에 비해 초등 예비교사들이 더 적극적으로 교과독서의 의미를 부각시키고 있었다. 과학에서의 독서활동이 많은 효과가 있다는 연구결과들을 비춰보면 학교 현장 수업에서 교수전략으로서 과학 교과독서에 대한 연구가 폭넓게 이루어져야 할 것으로 생각된다.

• 대한소아치과학회지
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• 제30권2호
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• pp.263-271
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• 2003

본 연구는 All-In-One system의 적용 시간과 도포횟수에 따라 유치 상아질과 복합레진의 접착 강도와 혼성층에 어떤 영향을 미치는지를 규명하고자 Single bonding agent(Scotchbond Multi-Purpose Plus, 3M, USA)와 All-In-One system(Prompt-L pop, 3M ESPE, USA)를 사용하였고 수복용 레진으로 복합레진(Z-250, 3M, USA)를 사용한 결과 다음과 같은 결과를 얻을 수 있었다. 1. 전단 결합 강도는 Single bonding agent를 적용한 경우 All-In-One system을 적용한 군보다 유의하게 높게 나타났다(P<0.05). 2. Prompt L-pop을 2회, 3회 적용한 경우에 전단 결합 강도는 1회 적용한 군보다 유의하게 높게 나타났으며(P<0.05), 혼성층의 두께는 1회 적용군보다 2회, 3회 적용한 군에서 증가하였다. 3. Prompt L-pop을 15초 적용한 경우에 전단 결합 강도는 7초 적용한 군보다 유의하게 높게 나타났으며(P<0.05), 30초 적용군과는 차이가 없었다. 혼성층의 두께는 7초 적용군이 가장 얇고, 15초군과 30초군에서는 차이가 없었다. 4. Single bonding agent를 이용한 경우 두터운 $2-4{\mu}m$의 혼성층이 관찰된 반면, All-In-One bonding system(Prompt L-pop, 3M ESPE, USA)에서는 비교적 얇은 혼성층($1-2{\mu}m$)이 형성되었다.

• Journal of Chest Surgery
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• 제26권8호
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• pp.654-660
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• 1993

The incidence of pulmonary leiomyosarcoma is very rare as a primary lung tumor. Usually, pulmonary leiomyosarcoma arise from the smooth muscle present in the bronchi or blood vessles. We had experienced two cases of primary pulmonary leiomyosarcoma. The first case was 28-year old male patient who had been in good health until admission, when he experienced an episode of dyspnea and sudden hemoptysis. The chest X-ray film revealed a large round tumor mass in left lower lobe measuring 6.5x9.5x5.3cm in dimension. On physical examination,the patient was friction rub and rales on the left lower chest and postoperative course was smooth and non-eventful. Emergency left lower lobectomy was performed due to repeated hemoptysis. Chemotheraphy was done postoperatively as an adjuvant therapy.The second case was 52-year-old man who had been well prior to admission, when recently he noticed a abrupt growing tendency of old pulmonary coin lesion in right lower lobe on routine physical examination. Since 1968, small round mass was gradually enlarged very slowly, during recent one year interval, the tumor mass was enlarged abruptly as twice in size on chest X-ray. Bronchoscopic examination revealed no specipic findings. Right lower lobectomy was performed and pathologic examination was answered as primary leiomyosarcoma without lymph node metastasis. Postoperative course was smooth, except local wound infection.