• 전기학회논문지
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• 제57권6호
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• pp.1058-1062
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• 2008

In clinical decision support system(CDSS), unlike rule-based expert method, appropriate data-driven machine learning method can easily provide the information of individual feature(clinical test) for disease classification. However, currently developed methods focus on the improvement of the classification accuracy for diagnosis. With the analysis of feature importance in classification, one may infer the novel clinical test sets which highly differentiate the specific diseases or disease states. In this background, we introduce a novel CDSS that integrate a classifier and feature selection module together. Random forest algorithm is applied for the classifier and the feature importance measure. The system selects the significant clinical tests discriminating the diseases by examining the classification error during backward elimination of the features. The superior performance of random forest algorithm in clinical classification was assessed against artificial neural network and decision tree algorithm by using breast cancer, diabetes and heart disease data in UCI Machine Learning Repository. The test with the same data sets shows that the proposed system can successfully select the significant clinical test set for each disease.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (B)
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• pp.175-177
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• 2003

This paper addresses a problem of classifying human breast cancer into its subtypes. A main ingredient in our approach is kernel machines such as support vector machine (SVM). kernel principal component analysis (KPCA). and kernel partial least squares (KPLS). In the task of breast cancer classification, we employ both SVM and KPLS and compare their results. In addition to this classification. we also analyze the patterns of clinical outcomes in the feature space. In order to visualize the clinical outcomes in low-dimensional space, both KPCA and KPLS are used. It turns out that these methods are useful to identify correlations between clinical outcomes and the nonlinearly protected expression profiles in low-dimensional feature space.

• 말소리와 음성과학
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• 제2권4호
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• pp.239-244
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• 2010

The purpose of this study is to investigate two phonological error patterns on coronal feature of children with functional articulation disorders and to compare them with those of general children. We tested 120 children with functional articulation disorders and 100 general children from 2~4 years of age with 'Assessment of Phonology & Articulation for Chidren(APAC)'. The results were as follows: (1) 37 disordered children substituted [+coronal] consonants for [-coronal] consonants (fronting of velars) and 9 disordered children substituted [-coronal] consonants for [+coronal] consonants (backing to velars). (2) Theses two phonological patterns were affected by the articulatory place of following phoneme. (3) The fronting pattern of children with articulation disorders was similar with that of general children, but their backing pattern was different with that of general children. These results show the clinical usefulness of coronal feature in phonological pattern analysis, the need of articulatory assessment with various phonetic context, and the importance of error contexts in clinical judgment.

• 사상체질의학회지
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• 제24권4호
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• pp.17-27
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• 2012

Objectives : This study proposes developing Sasang Medical Diagnosis Program using Facial form for increase in Sasang Constitution Diagnosis objectivity and putting the Diagnosis Program into practical use. The author presents a review of extant research on Sasang constitution diagnosis utilizing facial feature analysis and suggests an agenda for further research. Methods : For this thesis, a collection of dissertations on the subject of 'Usage of facial form for constitution diagnosis' published until September of 2012 such as RISS4U, OASIS, KISTI, Korean TK were reviewed. The final 33 dissertations were classified into two categories, basic or clinical research and then analyzed. Results : 9 out of 33 dissertations were of basic research and 24 were of clinical research. 1) As result of review of references, a uniform tendency was found in facial form according to Sasang Constitution. 2) In the grade of practical use, facial element is repeatedly used and the facial element of important use has constitutional differences. 3) Standard faces per Sasang Constitution were derived as result of 2-dimensional research. 4) 3-dimensional research focused on improvement of accuracy and reliability of 3D-AFRA, and there has been an attempt to develop a prototype for identification. Conclusions : For practical use of facial feature in Sasang Constitution Diagnosis, 1) Standardization of diagnosis through establishing Sasang Medical Diagnosis clinical protocol must be preceded. After the standardization, practical purpose and direction of facial form in general may be decided. 2) Information on high quality facial form of constitutional and conditional patients must be collected to form extensive database. 3) Subdivided symptomatology, as well as Sasang Constitution must be considered for diagnosis in order for diagnosis technique to acquire clinical practicality.

• Korean Journal of Radiology
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• 제24권6호
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• pp.498-511
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• 2023

Objective: To evaluate the diagnostic performance of chest computed tomography (CT)-based qualitative and radiomics models for predicting residual axillary nodal metastasis after neoadjuvant chemotherapy (NAC) for patients with clinically node-positive breast cancer. Materials and Methods: This retrospective study included 226 women (mean age, 51.4 years) with clinically node-positive breast cancer treated with NAC followed by surgery between January 2015 and July 2021. Patients were randomly divided into the training and test sets (4:1 ratio). The following predictive models were built: a qualitative CT feature model using logistic regression based on qualitative imaging features of axillary nodes from the pooled data obtained using the visual interpretations of three radiologists; three radiomics models using radiomics features from three (intranodal, perinodal, and combined) different regions of interest (ROIs) delineated on pre-NAC CT and post-NAC CT using a gradient-boosting classifier; and fusion models integrating clinicopathologic factors with the qualitative CT feature model (referred to as clinical-qualitative CT feature models) or with the combined ROI radiomics model (referred to as clinical-radiomics models). The area under the curve (AUC) was used to assess and compare the model performance. Results: Clinical N stage, biological subtype, and primary tumor response indicated by imaging were associated with residual nodal metastasis during the multivariable analysis (all P < 0.05). The AUCs of the qualitative CT feature model and radiomics models (intranodal, perinodal, and combined ROI models) according to post-NAC CT were 0.642, 0.812, 0.762, and 0.832, respectively. The AUCs of the clinical-qualitative CT feature model and clinical-radiomics model according to post-NAC CT were 0.740 and 0.866, respectively. Conclusion: CT-based predictive models showed good diagnostic performance for predicting residual nodal metastasis after NAC. Quantitative radiomics analysis may provide a higher level of performance than qualitative CT features models. Larger multicenter studies should be conducted to confirm their performance.

• Korean Journal of Radiology
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• 제21권12호
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• pp.1345-1354
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• 2020

Objective: To evaluate radiomics analysis in studies on mild cognitive impairment (MCI) and Alzheimer's disease (AD) using a radiomics quality score (RQS) system to establish a roadmap for further improvement in clinical use. Materials and Methods: PubMed MEDLINE and EMBASE were searched using the terms 'cognitive impairment' or 'Alzheimer' or 'dementia' and 'radiomic' or 'texture' or 'radiogenomic' for articles published until March 2020. From 258 articles, 26 relevant original research articles were selected. Two neuroradiologists assessed the quality of the methodology according to the RQS. Adherence rates for the following six key domains were evaluated: image protocol and reproducibility, feature reduction and validation, biologic/clinical utility, performance index, high level of evidence, and open science. Results: The hippocampus was the most frequently analyzed (46.2%) anatomical structure. Of the 26 studies, 16 (61.5%) used an open source database (14 from Alzheimer's Disease Neuroimaging Initiative and 2 from Open Access Series of Imaging Studies). The mean RQS was 3.6 out of 36 (9.9%), and the basic adherence rate was 27.6%. Only one study (3.8%) performed external validation. The adherence rate was relatively high for reporting the imaging protocol (96.2%), multiple segmentation (76.9%), discrimination statistics (69.2%), and open science and data (65.4%) but low for conducting test-retest analysis (7.7%) and biologic correlation (3.8%). None of the studies stated potential clinical utility, conducted a phantom study, performed cut-off analysis or calibration statistics, was a prospective study, or conducted cost-effectiveness analysis, resulting in a low level of evidence. Conclusion: The quality of radiomics reporting in MCI and AD studies is suboptimal. Validation is necessary using external dataset, and improvements need to be made to feature reproducibility, feature selection, clinical utility, model performance index, and pursuits of a higher level of evidence.

• 음성과학
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• 제11권1호
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• pp.65-72
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• 2004

The force of articulation is different between voiced and voiceless consonants in the binary opposition system. However, the Korean voiceless stop consonants have a triple opposition system: lenis, aspirated, and glottalized. The aim of this study is to find the primary distinctive feature between the force of articulation and the aspiration for the three different types of Korean stops. Two native speakers of the Seoul dialect participated to this study. The corpus was composed of less than eight syllabic words containing consonants in word-initial position and intervocalic position. Radiocinematography and Mingography were used to analyze the articulatory tension and acoustic characteristics. Korean stops have independent features of articulatory tension and aspiration, in which the indices are different according to position. However, in this system which does not have the opposition of sonority, the force of articulation is the primary distinctive feature and the feature of aspiration is subsidiary.

• Annals of Clinical Neurophysiology
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• 제3권1호
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• pp.40-42
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• 2001

Anorexia nervosa(AN) is a disorder characterized by disturbance of body image, fear of gaining weight, severe weight loss and, in female, amenorrhea. Compared with normal persons, patients with AN have neuropathic symptoms more frequently. But electrophysiologic abnormalities have rarely been reported. We experienced a case with recurrent neuropathic symptoms after severe weight loss. Further evaluation revealed AN. Electrophysiologic study showed sensorimotor polyneuropathy and focal neuropathy with conduction block. As far as we know, this feature of neuropathy in AN has not been described. We describe unusual feature of neuropathy in our patient with literature review.

• 혜화의학회지
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• 제24권1호
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• pp.37-46
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• 2015

Objective : This study aimed to explore the clinical feature of patients with dyspepsia who were treated by an Oriental internal medicine. Methods : We analyzed 130 patients who visited an Korean Medicine Hospital for their dyspepsia-related symptoms, from March 1, 2014 until to February 28, 2015 Results : The sex composition was consisted of 31.5% man and 68.5% woman, and 85.6% of outpatient and 14.4% of inpatient. The 39.2% of patients showed chronic complain (>6 months), and the main causes included stress and fatigue for 46.2% and 31.5% respectively. The accompanied symptoms were mainly fatigue (40.0%), insomnia (36.9%), abnormal stool (34.6%), upper back pain (31.5%), and headache (28.5%). The improvement rate was 68.5% while other (31.5%) showed no change of dysplasia. Conclusion : This study created an important information of patients with dysplasia, which will be critically helpful for development of Korean Medicine-based therapeutics in the future.

• 대한임상검사과학회지
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• 제42권3호
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• pp.111-115
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• 2010

A 15-year-old female with primary amenorrhea and Tuner's syndrome feature was referred for a chromosome analysis. The karyotype of the patient was 45,X/46,X,der(Y) mosaicism under initial GTG-banding analysis. Fluorescence in situ hybridization (FISH) analysis with probe for CEP X probes and SRY probe (Vysis, Inc. Downers Grove, IL 60515, USA) was carried out. This probe is direct labeled with SpectrumOrange (SRY, Yp11.3) and is available as a single probe or mixed with the CEP X SpectrumGreen probe. SRY SpectrumOrange/CEP X SpectrumGreen hybridized to a specimen obtained from an two isodicentric Y chromosomes. The karyotype of the patient was ish Xcen(DXZ1x1)/Xcen(DXZ1x1), Yp11.3(SRYx2) by using FISH. This karyotype was considered a variant of Tuner syndrome with mixed gonadal dysgenesis (MGD), male pseudohermaphroitism (MPH) and apparently normal male.