• The KIPS Transactions:PartB
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• v.9B no.5
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• pp.625-634
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• 2002

In this paper, we conducted various experiments with Bayesian networks in order to analyze clinical data of infertility patients. With these experiments, we tried to find out inter-dependencies among important factors playing the key role in clinical pregnancy, and to compare 3 different kinds of Bayesian network classifiers (including NBN, BAN, GBN) in terms of classification performance. As a result of experiments, we found the fact that the most important features playing the key role in clinical pregnancy (Clin) are indication (IND), stimulation, age of female partner (FA), number of ova (ICT), and use of Wallace (ETM), and then discovered inter-dependencies among these features. And we made sure that BAN and GBN, which are more general Bayesian network classifiers permitting inter-dependencies among features, show higher performance than NBN. By comparing Bayesian classifiers based on probabilistic representation and reasoning with other classifiers such as decision trees and k-nearest neighbor methods, we found that the former show higher performance than the latter due to inherent characteristics of clinical domain. finally, we suggested a feature reduction method in which all features except only some ones within Markov blanket of the class node are removed, and investigated by experiments whether such feature reduction can increase the performance of Bayesian classifiers.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.598-606
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• 1997

Among 136 patients having undergone mitral valve surgery from September of 1994 through August of 1995 in Sejong Heart Institute, forty four patients(18 males, 26 females) underwent mitral valve reconstruction using prosthetic rings and their clinical results were evaluated. Patients'ages ranged from 5 to 63 years(mean age 38.2 years). Mitral valvular diseases were due to rheumatic origin in 30 patients(68%), degenerative in 13(30%), and congenital in one patient(2%). Mitral regurgitation(MR) was in 33 patients(76%), mitral stenosis 2(5%), and mitral stenoinsufaciency 9 patients(19%). The patients were divided into Carpentier's functional groups : type I, 5 patients(11%) : type I, 24 patients(55%) ; type III, 4 patients (9%) i and mixed(II + III), 11 patients(25%). Average number of anatomic lesions of mitral valve per patient was 3.7. The techniques included prosthetic ring amluloplasty(44 patients, 32 Carpentier ring and 12 Duran ring), leaflet mobilization(24, 55%), chordae shortening(23, 52%), chordae transposition(23, 52%), commissurotomy(16, 35%), leaflet resection(9, 20%), papillary muscle splitting(8, 18%), and chordae reimplantation(1, 2%). Average 3.4 surgical procedures were applied on mitral valve per patient. There were two hospital mortality and one reoperation due to development of MR(grade III) after 2 weeks. During the mean follow up of 12 months, patients improved in terms of functional class of the New York Heart Association, which was mean 3.0 preoperatively and 1.3 postoperatively. Doppler echocardiographic studies showed adequate valve area(2.07$\pm$0.11 cm2 mean $\pm$standard error), improved ventricular contractiliy in 41 patients(93%), ab ence of MR in 23(53%), trace MR in 18(42%), and garde II MR in 2 patients(5%).

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.91-91
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• 2013

Imagine a world where we could biomanufacture hybrid nanomaterials having atomic-scale resolution over functionality and architecture. Toward this vision, a fundamental challenge in materials science is how to design and synthesize protein-like material that can be fully self-assembled and exhibit information-specific process. In an ongoing effort to extend the fundamental understanding of protein structure to non-natural systems, we have designed a class of short peptides to fold like proteins and assemble into defined nanostructures. In this talk, I will talk about new strategies to drive the self-assembled structures designing sequence of peptide. I will also discuss about the specific interaction between proteins and inorganics that can be used for the development of new hybrid solar energy devices. Splitting water into hydrogen and oxygen is one of the promising pathways for solar to energy convertsion and storage system. The oxygen evolution reaction (OER) has been regarded as a major bottleneck in the overall water splitting process due to the slow transfer rate of four electrons and the high activation energy barrier for O-O bond formation. In nature, there is a water oxidation complex (WOC) in photosystem II (PSII) comprised of the earthabundant elements Mn and Ca. The WOC in photosystem II, in the form of a cubical CaMn4O5 cluster, efficiently catalyzes water oxidation under neutral conditions with extremely low overpotential (~160 mV) and a high TOF number. The cluster is stabilized by a surrounding redox-active peptide ligand, and undergo successive changes in oxidation state by PCET (proton-coupled electron transfer) reaction with the peptide ligand. It is fundamental challenge to achieve a level of structural complexity and functionality that rivals that seen in the cubane Mn4CaO5 cluster and surrounding peptide in nature. In this presentation, I will present a new strategy to mimic the natural photosystem. The approach is based on the atomically defined assembly based on the short redox-active peptide sequences. Additionally, I will show a newly identified manganese based compound that is very close to manganese clusters in photosystem II.

• Journal of Preventive Medicine and Public Health
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• v.42 no.6
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• pp.403-407
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• 2009

Objectives : The amount of medical utilization by Medical Aid recipients was 3.7 times that of patients with Korean Medical Insurance. This study aims to describe the surplus medicine and the medication-related utilization, and to determine factors contributing to surplus medicine. Methods : Among those who used copayment-free Class I Medical Aid in 2005, 146,880 subjects who were $\geq19$ year-old and received >365 days medical treatment per year were studied with their case managers by conducting face-to-face interviews. The analytic methods were description, chi-square, t-tests, ANCOVA and multiple logistic regressions. Results : Most subjects were female (68.6%), the elderly (62.5%), and the separated (61.6%), had an elementary graduation or less (74.8%), and had disabilities (33.2%). The percentage of subjects with surplus medicine was 18.5%. However, the percentage of females, the elderly, those with non-disabilities, the separated, the uneducated, those with a very poor perceived health status and those with an economical burden for medical treatment was 19.3%, 18.9%, 19.0%, 19.3%, 19.0%, 20.2% and 24.3%, respectively. For subjects with surplus medicine, averages for the number of used pharmacies, the pharmacy-visit days and the medication costs were 4.6 drugstores, 34.9 days and approximately 1,124 thousand Won(￦). These values were higher than those without surplus medicine (4.4 drugstores, 33.8 days, and ￦1,110 thousand, respectively). The odds ratios of the contributing factors to surplus medicine were female 1.11 (95% CI=1.07-1.14), the elderly 1.06 (95% CI=1.02-1.10), those with non-disabilities 1.08 (95% CI=1.05-1.12), the separated 1.14 (95% CI=1.10-1.18), the unmarried 1.12 (95% CI=1.07-1.18), the uneducated 1.03 (95% CI=1.01-1.08), those with a very poor perceived health status 1.04 (95% CI=1.01-1.08) and experiencing an economical burden for medical treatment 2.33 (95% CI=2.26-2.40). Conclusions : 18.5% of subjects had surplus medicine with a higher mean of medication cost. Therefore, health education and health promotion programs to prevent surplus medicine and to improve the appropriate usage of medication are necessary.

• The Mathematical Education
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• v.59 no.1
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• pp.63-80
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• 2020

This study analyzed 3,114 articles published in KCI journals and 1,636 articles published in SSCI journals from 2000 to 2019 in order to compare domestic and international research trends of mathematics education using a topic modeling method. Results indicated that there were 16 similar research topics in domestic and international mathematics education journals: algebra/algebraic thinking, fraction, function/representation, statistics, geometry, problem-solving, model/modeling, proof, achievement effect/difference, affective factor, preservice teacher, teaching practice, textbook/curriculum, task analysis, assessment, and theory. Also, there were 7 distinct research topics in domestic and international mathematics education journals. Topics such as affective/cognitive domain and research trends, mathematics concept, class activity, number/operation, creativity/STEAM, proportional reasoning, and college/technology were identified from the domestic journals, whereas discourse/interaction, professional development, identity/equity, child thinking, semiotics/embodied cognition, intervention effect, and design/technology were the topics identified from the international journals. The topic related to preservice teacher was the most frequently addressed topic in both domestic and international research. The topic related to in-service teachers' professional development was the second most popular topic in international research, whereas it was not identified in domestic research. Domestic research in mathematics education tended to pay attention to the topics concerned with the mathematical competency, but it focused more on problem-solving and creativity/STEAM than other mathematical competencies. Rather, international research highlighted the topic related to equity and social justice.

• Journal of Korean Neurosurgical Society
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• v.60 no.1
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• pp.21-29
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• 2017

Objective : The purpose of this study was to analyze outcomes and identify prognostic factors in patients with cerebral metastases from non-small cell lung cancer (NSCLC) treated with gamma knife radiosurgery (GKS) particularly, focusing on associations of biomarkers and systemic treatments. Methods : We retrospectively reviewed the medical records of 134 patients who underwent GKS for brain metastases due to NSCLC between January 2002 and December 2012. Representative biomarkers including epidermal growth factor receptor (EGFR) mutation, K-ras mutation, and anaplastic lymphoma kinase (ALK) mutation status were investigated. Results : The median overall survival after GKS was 22.0 months (95% confidence interval [CI], 8.8-35.1 months). During follow-up, 63 patients underwent salvage treatment after GKS. The median salvage treatment-free survival was 7.9 months (95% CI, 5.2-10.6 months). Multivariate analysis revealed that lower recursive partition analysis (RPA) class, small number of brain lesions, EGFR mutation (+), and ALK mutation (+) were independent positive prognostic factors associated with longer overall survival. Patients who received target agents 30 days after GKS experienced significant improvements in overall survival and salvage treatment-free survival than patients who never received target agents and patients who received target agents before GKS or within 30 days (median overall survival: 5.0 months vs. 18.2 months, and 48.0 months with p-value=0.026; median salvage treatment-free survival: 4.3 months vs. 6.1 months and 16.6 months with p-value=0.006, respectively). To assess the influence of target agents on the pattern of progression, cases that showed local recurrence and new lesion formation were analyzed according to target agents, but no significant effects were identified. Conclusion : The prognosis of patients with brain metastases of NSCLC after GKS significantly differed according to specific biomarkers (EGFR and ALK mutations). Our results show that target agents combined with GKS was related to significantly longer overall survival, and salvage treatment-free survival. However, target agents were not specifically associated with improved local control of the lesion treated by GKS either development of new lesions. Therefore, it seems that currently popular target agents do not affect brain lesions themselves, and can prolong survival by controlling systemic disease status.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.489-499
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• 1998

Gonadal development, reproductive cycle and embryonic development of the marbled rockfish, Sebastiscus marmoratus were investigated histologically. A total of 1,035 specimens were collected from the Cheju Island from July of 1992 to May of 1996. Gonadosomatic index (GSI) in female reached the maximum during October to March, thereafter, the values decreased from Norvember to April. GSI in male reached the maximum in September (before one to three months of the female's maximum), thereafter, the values rapidly decreased from October to December. The annual reproductive cycle can be divided into five stages in female and four stages in male: females, Growing(June to September), Mature(September to February), Ripe and copulation(October to March), Gestation and parturition(November to April), Degenerative and resting(December to May); in males, Growing(April to July), Mature(August to November), Ripe and copulation(September to December), and Degenerstive and resting(November to March). Size frequency distribution of eggs and larvae showed non-synchrony. Maternal larvae parturition occurred one or two time during November to April. Mean length of the larvae parturition was 3.5 mm. Mean number of eggs and maternal larvae for the 15 cm minimum class of female was 58,377, and fecundity increased with the increase of total length and body weight.

• Journal of Korean Home Economics Education Association
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• v.20 no.3
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• pp.215-230
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• 2008

Activity materials in textbook could facilitate students' oriented self-help learning. The purpose of this paper is to find out characteristics of activity materials in the housing area of middle school Technology and Home Economics and teacher's perception of them. The data were collected from 253 middle school teachers who had ever taught the housing unit in any of 6 textbooks. The results showed that the number of activity materials were differed by the characteristics of the materials such as type of materials, feature of non sentence materials, and type of activity, depend on authors as well as textbooks. In general, teachers interests in the materials were higher than those of students even the trends of the interests were the same. Adequacy of activity contents and related knowledge of teachers were higher than adequacy of level. Teachers thought time and extra search beyond class were barrier to full the interests of students. Further research is suggested to find out whether higher interests in the materials are related to the higher activating rate of them.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.175-183
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• 2015

The proposed algorithm consists of two stages: the learning and synthesis stages. At the learning stage, we first collect various high-resolution (HR)-low-resolution (LR) text image pairs, and quantize the LR images, and extract HR-LR block pairs. Based on quantized LR blocks, the LR-HR block pairs are clustered into a pre-determined number of classes. For each class, an optimal 2D-FIR filter is computed, and it is stored into a dictionary with the corresponding LR block for indexing. At the synthesis stage, each quantized LR block in an input LR image is compared with every LR block in the dictionary, and the FIR filter of the best-matched LR block is selected. Finally, a HR block is synthesized with the chosen filter, and a final HR image is produced. Also, in order to cope with noisy environment, we generate multiple dictionaries according to noise level at the learning stage. So, the dictionary corresponding to the noise level of the input image is chosen, and a final HR image is produced using the selected dictionary. Experimental results show that the proposed algorithm outperforms the previous works for noisy images as well as noise-free images.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.71-81
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• 2006

Background: This study was done to better understand patterns, trends and local distribution patterns of malocclusion so that we can provide adequate information to patients, to help make the appropriate diagnosis and therapeutic plans, and to assess the future directions of malocclusion treatment. Materials and Methods: Malocclusion patterns, distribution and trends of visiting patients were examined in 993 malocclusion patients who had been evaluated and diagnosed at the Department of Dentistry, Yeungnam University Hospital over a 10-year period from 1995 to 2004. Results: The number of visiting patients per year showed an increasing trend and the visit rate was 1.28 time-higher in females(56.1%) than in males(43.9%). 1) Age distribution showed that the 7-12 year-old group was the largest (36.7%). Geographic distribution showed the majority of patients were from the Dalseo district(28.2%). Angle's malocclusion classification revealed that class III was the largest(38.4%). Crowding was the chief complaint in the highest percentage of patients(33.9%). The therapeutic method used was the fixed appliance in 61% of cases and a combination with extraction in 30.8%. Conclusions: The availability of dental services can accommodate orthodontic needs adequately as well as obtain reliable quantitative information regarding the characteristics of orthodontic patients.