• The Journal of the Acoustical Society of Korea
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• v.11 no.1
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• pp.35-41
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• 1992

A speaker identification scheme using the speaker-based VQ codecook of a sustained vowel is proposed and tested. With the pitch synchronous LPC vector of the sustained vowel /i/ as a feature vector, a VQ codebook size of 4 was found to be suitable to characterize each speaker's feature space. For 40 normal speakers (20 males, 20 females), we achieved the correct identification rate of 99.4% with a training data set, and 89.4% with a test data set with speech samples of only 50 pitch periods.

• The Journal of the Korean bone and joint tumor society
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• v.18 no.1
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• pp.1-6
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• 2012

Purpose: The purpose of this study was to analyze the results of treatment and prognosis of Marjolin's ulcer compared with primary squamous cell carcinoma. Materials and Methods: Fourteen patients treated for Marjolin's ulcer were analyzed. Twenty patients with primary squamous cell carcinoma treated during the same time period was the control group. Mean age was 61.2 years. There were 24 males and 10 females. The locations, TNM stages, histological grades, recurrence, metastasis, and survival rate were analyzed and compared between two groups. Results: The mean follow-up period was 54.8 months (range, 12-168 months). Local recurrences were found in 6 cases, 5 ones in Marjolin's ulcer patients, and one case in primary squamous cell carcinoma patients. The mean time interval between the initial presentation and occurrence of local recurrences was 9 months (range, 2-20 months). There were 6 metastases. 2 (14.3%) metastases were found in Marjolin's ulcer patients, and 4 (20.0%) metastases in primary squamous cell carcinoma patients. Total events (metastasis or local recurrence) were found in 10 pateients, 6 of them in Marjolin's ulcer group, and the remaining four in primary group. 5-year disease-free survival rate was 64.3% in Marjolin's ulcer group and 95.0% in primary squamous cell carcinoma group. Conclusion: Squamous cell carcinomas originating as Marjolin's ulcers revealed higher recurrence rate and lower survival rate despite of aggressive treatment. Therefore, new treatment modalities should be developed for improving outcomes.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.175-181
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• 2003

Primary chest wall tumors originate from soft tissue, bone or cartilage of the chest wall and it comprises 1∼2% of all primary tumors. Resection of tumor is often indicated for chronic ulceration or pain, and long-term survival might be achieved after surgery depending on the histology and the surgical procedure. Material and Method: Retrospective study of 125 primary chest wall tumors (86 benign, 39 malignant) operated between Sep. 1976 to Mar 2001 were reviewed and their clinical outcomes were analyzed. Follow-up data were collected at the outpatient clinic. Result: All patients with benign tumors were treated by excision without recurrence or death, and most malignancies were treated by wide resection. Malignant fibrous histiocytoma and chondrosarcoma constituted 46.2% of the malignant neoplasm. There was no operative death. The overall 3-year survival for patients with primary malignant neoplasm was 76.0%, and the 10-year survival was 60.5%. All deaths were disease-related and the tumor recurred in 11 patients. There was no significant difference in survival between patients with resection margins less than 4 cm and those with resection margins greater than 4 cm. Conclusion: Chest wall resection offers excellent results for benign chest wall tumors and substantial long-term survival for malignant diseases. Safe resection margin of 4 cm or more did not correlate with the survival rate although the tumor recurrence correlated with poor survival.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.319-325
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• 2022

The variation of utterance lengths is a representative factor that can degrade the performance of speaker verification systems. To handle this issue, previous studies had attempted to extract speaker features from various branches or to use convolution layers with different receptive fields. Combining the advantages of the previous two approaches for variable-length input, this paper proposes integrated receptive field diversification that extracts speaker features through more diverse receptive field. The proposed method processes the input features by convolutional layers with different receptive fields at multiple time-axis branches, and extracts speaker embedding by dynamically aggregating the processed features according to the lengths of input utterances. The deep neural networks in this study were trained on the VoxCeleb2 dataset and tested on the VoxCeleb1 evaluation dataset that divided into 1 s, 2 s, 5 s, and full-length. Experimental results demonstrated that the proposed method reduces the equal error rate by 19.7 % compared to the baseline.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.252-260
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• 2004

The purpose of study is to evaluate the clinical implication of malignant Pleural Lavage Cytology (PLC) in primary lung cancer. 315 patients were examined with pleural lavage cytology in Asan Medical Center between November 1998 and August 2002. The patients were chosen from primary lung cancer patients with no pleural effusion according to preoperative radiologic examination; no tumor invasion into the chest wall and no diffuse pleural adhesion in intraoperative findings, The pleural cavity and lung were washed with 100 $m\ell$ of warm normal saline. The 315 patients consisted of 237 men and 78 women. The incidence of malignant PLC was found in 28 patients (8.9%). For patients in early stages (I & II), survival rate was 93.9% in positive malignant PLC and 85.7% in negative malignant PLC. 31 patients (13.6%) had local or distant recurrences; 2-year recurrence-free rate was 90.1% in negative PLC and 87.5% in positive PLC. The survival and recurrence-free rate in each stage were not statistically associated with the result of PLC. Median follow-up was 16.4 months from the surgery. To access implication of malignant PLC in primary lung cancer, a long-term follow-up and further study are required.

• The Journal of the Acoustical Society of Korea
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• v.12 no.3
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• pp.62-67
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• 1993

부호 여기된 선형예측 음성보코더들은 4800bps의 낮은 전송율에서도 좋은 음질을 제공한다. CELP 형 보코더의 피치검색법의 문제점중에 하나는 피치 검출시의 조오류에 의해 예측이득이 저하된다는 점이다. 본 논문에서 우리는 CELP 보코더의 피치 예측이득을 개선하는 한 새로운 피치검색법을 제안하였다. 제안한 방법은 예비피치들을 검출하여 이들중 피치 예측이득이 최대인 값을 선정하는 방법을 적용하였다. 이 방법을 여러 화자의 발성에 대해 적용한 결과 피치 예측이득율 6.1% 정도 개선할 수 있었다.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.54-62
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• 1996

Background: $^{99m}Tc$ MIBI(Methoxyisobutylisonitrile complex), a member of the isonitrile class of coordination compounds, is a lipophilic cation presently under investigation for clinical use as myocardial perfusion imaging agent and is widely used to detect myocardial infarction. Preliminary reports indicate that $T_1$-201 accumulate in human neoplasm and several authors reported $^{99m}Tc$ MIBI may also localized in primary malignant tumor and metastatic deposits from lung cancer. We evaluated the uptake of $^{99m}Tc$ MIBI in lung cancer and localization of mediastinal and other site metastasis, and compared the benign lesion of the lung. Method: Thirty four patients of lung cancer and ten patients of benign lung lesion were studied with chest CT and $^{99m}Tc$ MIBI Lung SPECT. $^{99m}Tc$ MIBI uptake ratio was assessed by TR/NL(Lung lesion/ Normal area), HT/NL (Heart/Normal area) and HT/TR(Heart/Lung lesion). Results: 1) All lung cancer patients showed increased uptakes of $^{99m}Tc$ MIBI in malignant lung lesion and Tc-99m MIBI uptake was also increased in mediastinal and lymph node metastasis except two cases. 2) There was significant different ratio of TR/NL between malignant and benign lesion, $3.79{\pm}1.82$ and $1.67{\pm}0.63$ on planar images, respectively(p<0.001). 3) There was no significant difference of $^{99m}Tc$ MIBI uptake ratio between squamous cell carcinoma, small cell carcinoma and adeno carcinoma($3.64{\pm}1.66$, $3.57{\pm}0.72$, $4.31{\pm}2.28$ respectively). Conclusion: $^{99m}Tc$ MIBI lung SPECT was useful in the localization of tumor and mediastinal or other site metastatic lesion in lung cancer and also in the differential diagnosis between benign and malignant lesion.

• The Journal of the Acoustical Society of Korea
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• v.24 no.3
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• pp.150-159
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• 2005

This paper addresses a voice personality transformation algorithm which makes one person's voices sound as if another person's voices. In the proposed method, one person's voices are represented by LPC cepstrum, pitch period and speaking rate, the appropriate transformation rules for each Parameter are constructed. The Gaussian Mixture Model (GMM) is used to model one speaker's LPC cepstrums and conditional probability is used to model the relationship between two speaker's LPC cepstrums. To obtain the parameters representing each probabilistic model. a Maximum Likelihood (ML) estimation method is employed. The transformed LPC cepstrums are obtained by using a Minimum Mean Square Error (MMSE) criterion. Pitch period and speaking rate are used as the parameters for prosody transformation, which is implemented by using the ratio of the average values. The proposed method reveals the superior performance to the previous VQ-based method in subjective measures including average cepstrum distance reduction ratio and likelihood increasing ratio. In subjective test. we obtained almost the same correct identification ratio as the previous method and we also confirmed that high qualify transformed speech is obtained, which is due to the smoothly evolving spectral contours over time.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.339-346
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• 2000

Background : The moot important prognostic factor in non-small cell lung cancer is the TNM stage. Even after complete resection in early non-small cell lung cancer, the five-year survival rate is still low. However, new prognostic factors, including molecular biologic factors, have recently been found to guide the treatment of patients with non-small cell lung cancer. We evaluated the prognostic value of the loss of blood-group antigen A in tumor tissue, which has been implicated as an important prognostic factor for overall survival and the timing of the disease progression. Methods : The loss of blood-group antigen A was assessed immunohistochemically in paraffin-embedded tumor samples from 26 patients with blood types A or AB, who had undergone curative surgery. Monoclonal antibody was used to detect the blood group antigen A expression. Results : Fifteen patients (58%) expressed antigen A in their tumor tissue, whereas 11 patients (42%) did not show antigen A. The median survival time of the blood A antigen positive group was 11 months, while the median survival time of the blood A antigen negative group was 18 months. The difference in survival between the two groups was not statistically significant. Conclusion : The loss of blood-group antigen A in tumor tissue was not found to be a significant prognostic factor in patients with non-small cell lung cancer. This study needs to be extended for further evaluation.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.1
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• pp.44-50
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• 2008

Purpose: To evaluate usefulness in diagnosing primary malignant lesion of metastatic bone tumor using $^{18}F$ FDG PET/CT. Material & Methods: Retrospective analysis was executed on 5,452 patients who were taken with $^{18}F$ FDG PET/CT between December 2003 and December 2007. 180 patients who had not any history of malignancy and complained musculoskeletal pain and had ill-defined osteolytic lesion in plain X-ray, were included. 96 male and 84 female were enrolled and mean age was 59.1 year old (22~90). We analyzed diagnostic accuracy, age and sex distribution of primary malignant lesion, location of metastatic lesion. Results: We could confirmed primary malignant lesion in 152 cases (84.4%). Most common malignant primary lesion was lung (28.3%), breast (18.9%) and gastrointestinal system (16.7%) and spine was the most common metastatic location of primary malignant lesion. Conclusion: $^{18}F$ FDG PET/CT is a effective molecular imaging detecting primary malignant lesion in patients having metastatic bone lesion without history of malignancy.