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

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.315-323
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• 2000

Background : An immunochromatographic assay (ICT Diagnostics) which facilitates the diagnosis of tuberculosis(TB) by detecting serum antibodies mainly directed against specific 38KDa of Mycobacterium tuberculosis has come into the market. The test consists of a cardboard folding device containing nitrocellulose strip and absorbent pads. The whole procedure is completed within 15 min and does not require any additional equipment. The test has been reported to be sensitive and specific in diagnosing active TB. Thus the test had been evaluated with sera from TB patients and TB-free subjects. Method : Sera from patients with active pulmonary tuberculosis(40 sputum positives for Mycobacterium tuberculosis, 79 sputum negatives, and 3 extrapulmonary tuberculosis) were obtained from the Double-Cross Chest Clinic of the Korean National Tuberculosis Association (KNTA) in Seoul. The control group consisted of TB-free 68 subjects(21 children under 7 years old and 47 healthy staff members of KNTA). Results : Nine out of 68(13.2%) TB-free controls had positive antibody response. Total 106 of 122(86.9%) radiologically active patients had positive antibodies while 16 (13.1%) showed negative reaction. Antibody was detected in 38 of 40(95.0%) sputum positive patients and 68 of 82(82.9%) sputum negative patients who were under the antituberculosis chemotherapy. The sensitivity and specificity were all 87% and the positive predictive value was 92.2% while the negative predictive value was 78.7%, when the prevalence of TB in the sample was 64.2%. Our results clearly show that the detection of antibodies which mainly react with the 38KDa antigen of M. tuberculosis is not suitable as the first-line method of diagnosis but considered only as an adjunctive test to standard techniques of tuberculosis diagnosis. when considering its high false positivity.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.26-32
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• 2014

Purpose: As PET-MRI which has excellent soft tissue contrast is developed as integration system, many researches about clinical application are being conducted by comparing with existing display equipments. Because PET-MRI is actively used for head and neck cancer diagnosis in our hospital, lymph node metastasis before the patient's surgery was diagnosed and clinical usefulness of head and neck cancer PET-MRI scan was evaluated using pathological opinions and idiopathy surrounding tissue metastasis evaluation method. Materials and Methods: Targeting 100 head and neck cancer patients in SNUH from January to August in 2013. $^{18}F-FDG$ (5.18 MBq/kg) was intravenous injected and after 60 min of rest, torso (body TIM coil, Vibe-Dixon) and dedication (head-neck TIM coil, UTE, Dotarem injection) scans were conducted using $Bio-graph^{TM}$ mMR 3T (SIEMENS, Munich). Data were reorganized using iterative reconstruction and lymph node metastasis was read with Syngo.Via workstation. Subsequently, pathological observations and diagnosis before-and-after surgery were examined with integrated medical information system (EMR, best-care) in SNUH. Patient's diagnostic information was entered in each category of $2{\times}2$ decision matrix and was classified into true positive (TP), true negative (TN), false positive (FP) and false negative (FN). Based on these classified test results, sensitivity, specificity, accuracy, false negative and false positive rate were calculated. Results: In PET-MRI scan results of head and neck cancer patients, positive and negative cases of lymph node metastasis were 49 and 51 cases respectively and positive and negative lymph node metastasis through before-and-after surgery pathological results were 46 and 54 cases respectively. In both tests, TP which received positive lymph node metastasis were analyzed as 34 cases, FP which received positive lymph node metastasis in PET-MRI scan but received negative lymph node metastasis in pathological test were 4 cases, FN which received negative lymph node metastasis but received positive lymph node metastasis in pathological test was 1 case, and TN which received negative lymph node metastasis in both two tests were 50 cases. Based on these data, sensitivity in PET-MRI scan of head and neck cancer patient was identified to be 97.8%, specificity was 92.5%, accuracy was 95%, FN rate was 2.1% and FP rate was 7.00% respectively. Conclusion: PET-MRI which can apply the acquired functional information using high tissue contrast and various sequences was considered to be useful in determining the weapons before-and-after surgery in head and neck cancer diagnosis or in the evaluation of recurrence and remote detection of metastasis and uncertain idiopathy cervical lymph node metastasis. Additionally, clinical usefulness of PET-MRI through pathological test and integrated diagnosis and follow-up scan was considered to be sufficient as a standard diagnosis scan of head and neck cancer, and additional researches about the development of optimum MR sequence and clinical application are required.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.109-111
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• 2004

발성율은 일정한 시간동안 발성되는 음성신호 내에 몇 개의 음절이 포함되어 있는 지를 나타낸다. 발성율은 화자마다 다르고 각 음소들의 특징에 따라 변화할 수 있다. 발성율의 사전 측정이 이루어 진다면 음성부호화 측면에서도 중용한 정보로 사용될 수 있다. 기존의 음성부호화기는 발성율에 관계없이 고정적인 분석 구간을 정하여 전송률을 결정하고 있다. 따라서, 발성율을 미리 측정한다면, 발성율이 느린 부분과 빠른 부분에 각기 다른 부호화 방법을 적용하여 음질을 향상할 수도 있고 전송률을 가변적으로 적용할 수 도 있게 된다. 정확한 발성율을 측정하기 위해서는 음절의 변화를 추정하여야 한다. 음절의 변화를 추정하기 위한 방법으로 음성신호의 에너지 포락선 측정법과 LSP를 이용한 측정법이 각각 제안된 바 있으나, 본 논문에서는 위 두 가지 방법을 혼합한 방법을 사용하였다. 에너지 변동은 음성신호의 시간영역 처리방법으로 LSP 파라미터는 음성신호의 선형예측 분석에 의해 구해질 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.592-594
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• 2001

본 연구에서는 음성인식에 있어서 음향모델의 고정도화를 위해 통계적 방법인 HMM과 시간동기형 Viterbi 알고리즘을 기반으로 한 세그멘트되지 않은 음성의 자동 세그멘테이션에 관한 연구를 수행하였다. 본 연구에서는 소량의 세그멘트된 음성에 대해 연속분포형 HMM 기본모델을 작성한 후 이를 표준패턴으로 사용하고, 세그멘트되지 않은 입력음성의 특징 피라미터에 대해 시간동기형 Viterbi 알고리즘의 프레임마다 최대가 되는 지점을 최적경계로 설정하고, 앞에서 구현 최적 경계 정보와 언어학적 지식인 발음사전 정보를 이용하여 음성을 세그멘테이션 하는 것이다. 본 연구와의 비교를 위해 HTK를 이용하여 위와 동일한 과정을 수행하였다. 이렇게 구한 음성의 세그멘테이션 정보를 이용하여 연속분포형 HMM 기본모델과 HTK의 CHMM 기본모델을 각각 작성한 후, 국어공학센터(KLE) 단어 데이터에 대해 단어인식 성능을 평가하였다. 실험결과, KLE 452 남성과 여성에 대해, 본 연구실 인식 시스템은 화자독립 단어인식률 89.4%, 85.1%, HTK의 화자독립 단어인식률 85.1%, 81.9%를 각각 얻었다.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.169-180
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• 1999

Background: Uterine cervical cancer is the most common malignant tumor of the women in Korea. This study was undertaken to evaluate the usefulness of the cervicography as a screening test of cervical cancer. Materials and Methods: Cervicography was taken from 482 women at department of obstetrics and gynecology, at Yeungnam University Hospital from March 1, 1998 to October 31, 1999. Of the 482 women, 172 women were exc1uded from the study for various reasons, and 310 women completed the study. Three-hundred and ten women had cervical cytology (Papanicolaou smear), cervicography and colposcopy, and punch biopsy was undertaken if any of the test result was abnormal. Results: The most common age group was 35-39, and 40-44, 45-49 in order and most common reason for having a screening test was regular check for cervical cancer. The mean duration from the last Pap smear was 17.1 months, and 64 women(20.4%) never had any prior screening tests. Of the 310 women, 254 women were categorized as normal or having benign disease such as cervicitis, erosion or metaplasia. Biopsy was taken from 56 patients and the results were 26 chronic cervicitis, 4 mild dysplasia, 6 moderate dysplasia, 2 severe dysplasia, 14 carcinoma in situ and 4 invasive carcinoma. The results of cytology and cervicography were well correlated(p<0.05). The sensitivity and specificity of cytology were 86.7% and 76.9%, respectively and the sensitivity and specificity of cervicography were 56.7% and 96.2%, respectively. False negative rate of cervicography(43.3%) was much higher than those of cytology(13. 3%) (p<0.05), but false positive rate of cervicography(3.8%) was much lower than that of cytology(23.1%) (p<0.05). Conclusion: It seems inappropriate to use cervicography as a single screening test for cervival cancer, but it may be an effective complementary test for cytology to lower the false negative rate of cytology.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2
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• pp.41-48
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• 1997

This paper proposes the methods for improving the recognition rate of theARS, especially equipped with the speech recognition capability. Telephone speech, which is the input to the ARS, is usually affected by the announcements from the system, channel noise, and channel distortion, thus directly applying the recognition algorithm developed for clean speech to the noisy telephone speech will bring the significant performance degradation. To cope with this problem, this paper proposes three methods: 1)the accurate detection of the inputting instant of the speech in order to immediately turn off the announcements from the system at that instant, 2)the effective end-point detection of the noisy telephone speech on the basis of Teager energy, and 3)the SDCN-based compensation of the channel distortion. Experiments on speaker-independent, noisy telephone speech reveal that the combination of the above three proposed methods provides great improvements on the recognition rate over the conventional method, showing about 77% in contrast to only 23%.

• Proceedings of the Acoustical Society of Korea Conference
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• 1997.06a
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• pp.17-22
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• 1997

본 논문에서는 음성 인식기의 성능을 저하시키는 요인중 부가 잡음과 마이크의 변동에 의한 채널 왜곡을 동시에 감소시키는 방법으로 기존의 전처리에 의한 환경덥음처리기법의 단점을 개선한 Histogram 처리기법을 잡음처리에 도입하고 그 유효성을 확인하였다. 도입한 잡음처리기법의 유효성을 확인하기 위하여 기존의 잡음처리기법으로 잘 알려진 여러 가지 방법과 비교하기 위하여 단어 인식실험을 실시하였다. 실험결과, 부가잡음만이 첨가된 경우에 있어서는 일반적으로 알려진 SS, CMN, RASTA등을 이용한 결과 전처리방법을 이용하지 않은 경우의 기본인식률에 비해 SN비에 따라 25% 이상이 인식률 향상을 볼 수 있었다. 특히 CDCN 처리와 H-RASTA를 사용한 경우, 채널왜곡과 부가잡음이 함께 포함된 음성에 대해 SN비에 관계없이 약 15~30%정도의 인식률의 향상을 볼 수 있어 기존 방법으로서는 이글 방법이 우수함을 확인할 수 있었다. 이 위에 Histogram 에 의한 추정법을 적용한 경우 전처리의 성능을 10~15% 정도 성능향상을 가져와 도입한 방법의 유효성을 확인할 수 있었다.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.88-91
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• 2000

개인용 컴퓨터가 멀티미디어 환경으로 변함에 따라서 인식률 향상과 처리시간 단축을 요구하고 있다. 본 논문은 기준패턴의 수가 증가함에 따라 발생하는 처리시간 증가 문제의 해결과 인식률 향상에 관한 것이다. 기준패턴의 수를 줄이기 위한 방법으로 각 모음별 포만트 정보를 구한 뒤 시험패턴과 비교할 후보자를 미리 정하여 인식률을 향상시키는 방법을 제안하고자 한다. 위와 같은 방법으로 모의 실험한 결과 전체 시스템 인식률이 기존의 방법에 비하여 0.5% 정도 향상되었고, 처리시간은 10%정도 감소하였다.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.218-220
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• 2010

85명의 유방암 환자를 대상으로 이들의 유방영상을 검토하고 유방암 환자들의 특징을 살펴보고자 한 본 논문에서 유방암 환자들의 평균나이는 51.9세이었고, 유방암이 가장 많이 발생하는 부위는 상외측(43.5%)인 것으로 조사되었으며, 유방암이 가장 많이 발생하는 연령은 40대 인 것으로 조사되었다. 유방암 환자들의 유방조직밀도는 69.4%가 dense breast이었고, 30.6%가 fatty breast인 것으로 조사되었으며, 이 두 그룹의 평균연령은 dense breast를 가진 그룹이 유의하게 낮은 것으로 조사되었다. 유방영상의 위음성률은 27.1%, 민감도는 72.9%로 조사되었고, dense breast를 가진 환자들의 유방영상 위음성률은 32.2%, 민감도는 67.8%로 조사되었다.