• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.5
• /
• pp.84-90
• /
• 2004

A prediction of SEE rates for a candidate microprocessor is made based on the ground experiment results with a proton accelerator. Populations of charged particles in space are estimated with numerical models such as AP8, JPL91 and CREME. The cross section curves that are previously obtained with the accelerator are then employed for SEE prediction. Both the high and low inclinations are considered for low-earth orbits with nominal altitudes of about 685km. The results show that the occurrence rate of SEEs for the candidate device is acceptable for low-inclinations, but can be considerable under worst conditions for high inclinations.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2019.10a
• /
• pp.60-60
• /
• 2019

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2008.10a
• /
• pp.272-277
• /
• 2008

본 연구의 목적은 U-City의 인력양성을 효율적으로 지원하기 위한 정책방향을 설정하는 것이다. 이를 위해서 지자체의 개략적인 U-City의 사업비 규모를 설정하고, 이에 대한 소요 인력을 예측하였으며. 국내시장과 해외시장의 증가율을 고려하여 개략적인 소요인력을 산정하였다. 또한 현재 정부에서 추진 중인 U-City 인력양성 정책의 방향에 대하여 고찰함으로써 현재 국내의 U-City 사업관련 인력양성의 방향을 살펴보았다.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1993.05a
• /
• pp.104-104
• /
• 1993

Fine needle aspiration cytology(FNAC) is a valuable method in preoperative diagnosis of thyroid nodule. Authors evaluated one hundred and ten thyroid nodules by FNAC compared with the postoperative histopathologic diagnosis during the period from Jan. 1, 1989 through Dec. 31, 1992. The results were as followed. The sensitivity was 86.5%, specificity 90.4%, false-negative rate 13.5%, false-positive rate 9.6%, positive predictability 91.5%, negative predictability 60.1% and overall diagnostic accuracy 87.3 %.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.3
• /
• pp.311-320
• /
• 1999

Background: In recent years, tuberculosis has re-emerged as a major health problem in both industrialized & developing countries. Recent advances in identifying & purifying antigens secreted in active tuberculosis infection have lead to the development of serological assays based on a number of immunodominant antigens. To date, the most sensitive and specific of these antigens has been the 38-kDa antigen. Method: Two rapid membrane-based serologic assays using antigen(38-kDa) from mycobacterium tuberculosis for the diagnosis of tuberculosis were evaluated in 22 patients with smear-positive pulmonary tuberculosis, 14 patients with inactive pulmonary tuberculosis, and 9 patients with non-tuberculous lung disease. Result: The evaluation of validity(sensitivity, specificity, positive predictive value, negative predictive value, false positivity and false negativity) of STAT-PAK ULTRA FAST$^{(R)}$ were 77.3%, 28.6%, 63.0%, 44.4%, 71.4 %, and 22.7% for differential diagnosis of active pulmonary tuberculosis and inactive pulmonary tuberculosis, respectively. The evaluation of validity of STAT-PAK ULTRA FAST$^{(R)}$ were 77.3%, 33.3%, 73.9%, 37.5%, 66.7%, and 22.7% for differential diagnosis of active pulmonary tuberculosis and non-tuberculosis. The evaluation of validity of ICT Tuberculosis$^{(R)}$ were 54.5%, 57%, 66.7%, 44.4%, 42.9%, and 45.5% for differential diagnosis of active pulmonary tuberculosis and inactive pulmonary tuberculosis. The evaluation of validity of ICT Tuberculosis$^{(R)}$ were 54.5%, 100%, 100%, 47.4%, 0%, and 45.4% for differential diagnosis of active pulmonary tuberculosis and non-tuberculosis. Conclusion: We concluded no effectiveness of STAT-PAK ULTRA FAST$^{(R)}$ & ICT tuberculosis$^{(R)}$on serologic diagnosis of pulmonary tuberculosis. In the future, further large-scale study should be needed for serologic diagnosis of pulmonary tuberculosis.

• Korean Journal of Head & Neck Oncology
• /
• v.27 no.1
• /
• pp.32-37
• /
• 2011

서 론 : 미세갑상선유두상암종 환자에서 불필요한 예방적 중앙 림프절절제술을 피하기 위해서 림프절 전이를 수술 전에 예측하는 수단이 필요하다. 림프관 생성 및 성장의 조절에 VEGF-C/D, VEGFR-3 pathway, podoplain이 관여된다는 사실이 밝혀져 있다. 림프관 생성 및 성장과 관련된 인자인 VEGF-C/D, podoplanin에 대한 면역조직화학염색과 반정량적 분석을 통해 미세갑상선유두상암종에서 림프절전이와의 관련성을 확인하고자 하였다. 대상 및 방법 : 2006년 9월부터 2008년 6월까지 본원에서 미세갑상선유두상암종으로 진단받고 1인 술자에 의해 갑상선 전 절제술 및 예방적 중앙 림프절절제술을 받은 104명의 환자 중 중앙 림프절 전이가 있었던 환자와 없었던 환자를 각각 25명씩 무작위로 선별하여 종양부위에 면역화학염색을 실시하여 림프관생성인자의 발현 정도를 비교하였다. 결 과 : 대상군 50예 중 VEGF-C/D는 50예(100%) 모두 발현이 되었고 podoplanin은 33예(66%)에서 발현이 되었다. 그 중 VEGF-C는 10예(20%)에서 약한 양성, 37예(74%)에서 중등도 양성, 3예(6%)에서 강한 양성소견을 보였고 VEGF-D는 9예(18%)에서 약한 양성, 37예(74%)에서 중등도 양성, 4예(8%)에서 강한 양성소견을 보였다. 중앙 림프절 전이 음성 환자 군과 양성 환자 군으로 분류하였을 때 VEGF-C/D의 발현율의 차이는 p-value가 각각 0.48, 1.00으로 통계적으로 유의한 차이를 보이지 않았다. 50예 전체를 대상으로 하여 종양의 개수, 최대크기, 검출된 전체 림프절의 수, 양성 림프절의 수, 주변조직 침범여부에 따른 VEGF-C/D의 발현도 통계적으로 유의한 차이를 보이지 않았다. Podoplanin의 경우 염색 여부에 따라 양성군과 음성군으로 나누어 분석하였을 때 종양의 개수, 최대크기, 검출된 림프절의 수, 양성 림프절의 수, 주변조직 침범여부도 통계적으로 유의한 차이를 보이지 않았다. 결 론 : VEGF-C/D는 대상군 전체(100%)에서 발현이 되었고 podoplanin은 66%에서 발현이 되었다. 림프관 생성인자로 알려진 VEGF-C/D및 podoplanin이 미세갑상선유두상암종에서 많이 발현이 되는 것으로 보아 위 인자들이 림프절 전이를 일으키는 인자 중 하나로 생각된다. 하지만 미세갑상선유두상암종에서 중앙 림프절 전이를 예측할 수 있는 인자로 부적합 한 것으로 생각되며 향후 더 많은 증례를 통해 관련성 여부에 대한 연구가 필요하고 또 다른 인자의 관련성에 대해서 연구가 필요하겠다.

• Tuberculosis and Respiratory Diseases
• /
• v.61 no.6
• /
• pp.547-553
• /
• 2006

Background: Liquid-based cytology is currently known as an effective method, and cervical cytology has been shown to be especially effective from of malignancy detection. In our study, the cytological detection rates of the Thinprep (Liquid-based cytology) and conventional cytology (bronchial washing & brushing) for endobronchial lesions were compared. Methods: Between July 2005 and September 2005, the data from 30 patients with respiration symptom, who had shown abnormal lesion on bronchoscopy, were collected. Results: The bronchoscopic biopsy group was consisted of 30 cytodiagnosis specimens, 24 of which were confirmed to be malignant. The others were tuberculosis (4), bronchiectasis and bronchopulmonary fistula (1 each). Of the 24 malignant case, cancer or atypical cells were detected in 19, 17 and 12 of the Thinprep, brushing cytology and washing cytology cases, respectively. None one of the methods detected cancer cells in the non-malignant specimens. Washing cytology has shown sensitivity, specificity, and positive and negative predictive values of 50, 100, 100 and 33.3% respectively. Brushing cytology has shown sensitivity, specificity, and positive and negative predictive values of 70.8, 100, 100 and 46.2%, respectively. Thinprep has shown sensitivity, specificity, and positive and negative predictive values of 79.2, 100, 100 and 54%, respectively. Conclusions: Thinprep (liquid-based cytology) showed better sensitivity and negative predictive values for the evaluation of lung cancer than conventional cytology. However a large-scale study will be needed in the future.

• The Korean Journal of Nuclear Medicine
• /
• v.32 no.3
• /
• pp.259-265
• /
• 1998

Purpose: We studied early rest/24 hour delay T1-201 perfusion SPECT for prediction of wall motion improvement after reperfusion in patients with acute myocardial infarction. Materials and Methods: Among 17 patients (male/female= 11/6, age: $59{\pm}13$) with acute myocardial infarction, 15 patients were treated with percutaneous transcoronary angioplasty (direct:2, delay: 11) and intravenous urokinase (2). Spontaneous resolution occurred in infarct-related arteries of 2 patients. We confirmed TIMI 3 flow of infarct-related artery after reperfusion in all patients with coronary angiography. We performed rest T1-201 perfusion SPECT less then 6 hours after reperfusion and delay T1-201 perfusion SPECT next day. T1-201 uptake was visually graded as 4 point score from normal (0) to severe defect (3). Rest T1-201 uptake ${\le}2$ or combination of rest T1-201 uptake ${\le}2$ or late reversibility were considered to be viable. Myocardial wall motion was graded as 5 point score from normal (1) to dyskinesia (5). Myocardial wall motion was considered to be improved when a segment showed an improvement ${\ge} 1$ grade in follow up echo compared with the baseline values. Results: Among 98 segments with wall motion abnormality, the severity of myocardial wall motion decrease was as follow: mild hypokinesia: 18/98 (18%), severe hypokinesia: 28/98 (29%), akinesia: 51/98 (52%), dyskinesia: 1/98 (1%). The wall motion improved in 85%. Redistribution (13%), and reverse redistribution (4%) were observed in 24 hour delay SPECT. Positive predictive value (PPV) and negative predictive value (NPV) of combination of late reversibility and rest T1-201 uptake were 99%, and 54%. PPV and NPV of rest T1-201 uptake were 100% and 52% respectively. Predictive values of combination of rest T1-201 uptake and late reversibility were not significantly different compared with predictive values of rest T1-201 uptake only. Conclusion: We conclude that early T1-201 perfusion SPECT predict myocardial wall motion improvement with excellent positive but relatively low negative predictive values in patients with acute myocardial infarction after reperfusion.

• Tuberculosis and Respiratory Diseases
• /
• v.61 no.1
• /
• pp.34-40
• /
• 2006

Background: Extubation failure was associated with poor prognosis and high hospital mortality. Cuff leak test (CLT) has been proposed as a relatively simple method for detecting laryngeal obstruction that predispose toward postextubation stridor (PES) and reintubation. We examined the risk factors of extubation failure and evaluated the usefulness and limitation of CLT for predicting PES and reintubation. Methods: Thirty-four consecutive patients intubated more than 24 hours were examined. The subjects were evaluated daily for extubation readiness, and CLT was performed prior to extubation. Several parameters in the extubation success and failure group were compared. The accuracy and limitation of CLT were evaluated after choosing the thresholds values of the cuff leak volume (CLV) and percentage (CLP). Results: Of the 34 patients studied, 6 (17.6%) developed extubation failure and 3 (8.8%) were accompanied by PES. The patients who had extubation failure were more likely to have a longer duration of intubation and more severe illness. The patients who developed PES had a smaller cuff leak than the others: according to the CLV ($22.5{\pm}23.8$ vs $233.3{\pm}147.1ml$, p=0.020) or CLP ($6.2{\pm}7.3$ vs $44.3{\pm}24.7%$, p=0.013). The best cut off values for the CLV and CLP were 50ml and 14.7%, respectively. The sensitivity, negative predictive value, and specificity of CLT were relatively high, but the positive predictive value was low. Conclusion: The likelihood of developing extubation failure increases with increasing severity of illness and duration of intubation. A low CLV or CLP (<50ml or 14.7%) is useful in identifying patients at risk of PES, but the CLT is not an absolute predictor and should not be used an indicator for delaying extubation.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04b
• /
• pp.247-249
• /
• 2002

협력적 여과(collaborative filtering) 방법을 사용하는 추천 시스템에서 예측 정확도를 높이는 방법들 중 하나는 군집화(clustering)방법이 있다. 군집화 방법은 선호도가 유사한 사용자들을 미리 같은 군집으로 만들고, 군집 내에 속한 사용자들을 이웃으로 선정하여 예측을 수행하기 때문에 군집화의 결과가 예측의 정확도에 직접적인 영향을 주게 된다. 본 연구에서는 군집화 결과의 향상을 위해 데이터를 전 처리하는 두 가지 방법과 군집화의 특성을 이용한 새로운 예측식을 제안하고, 기존 연구 방법과의 비교 실험을 통해 실험결과를 분석한다.