• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.130.1-130.1
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• 2013

We made attempts to improve photocatalytic activity of $TiO_2$ nanoparticles under visible light exposure by combining two additional treatments. N-doping of $TiO_2$ by ammonia gas treatment at $600^{\circ}C$ increased absorbance of visible light. By coating thin film of polydimethylsiloxane (PDMS), and subsequent vacuum-annealing at $800^{\circ}C$, $TiO_2$, became more hydrophilic, thereby enhancing photocatalytic activity of $TiO_2$. Four types of $TiO_2$ samples were prepared, bare-$TiO_2$, hydrophilic-modified $TiO_2$ ($h-PDMS/TiO_2$), N-doped $TiO_2$ ($N/TiO_2$) and hydrophilic-modified and N-doped $TiO_2$ ($h-PDMS/N/TiO_2$). Adsorption capability was evaluated under dark condition and photocatalytic activity of $TiO_2$ was evaluated by photodegradation of MB under blue LED (400 nm< ${\lambda}$) irradiation. N-doping on $TiO_2$ was characterized using XPS and hydrophilic modification of $TiO_2$ surface was analyzed by FT-IR spectrometer. It was found that N-doping and hydrophilic modification both had positive effect on enhancing adsorption capability and photocatalytic activity of $TiO_2$ at the same time. Particularly, N-doping enhanced visible light absorption of $TiO_2$, whereas hydrophilic surface modification increased MB adsorption capacity. By combining these two strategies, photocatalytic acitivity under visible light irradiation became the sum of individual effects of N-doping and hydrophilic modification.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.107-116
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• 2019

The global obesity epidemic and associated metabolic diseases require alternative biological targets for new therapeutic strategies. In this study, we show that a phytochemical sulfuretin suppressed adipocyte differentiation of preadipocytes and administration of sulfuretin to high fat diet-fed obese mice prevented obesity and increased insulin sensitivity. These effects were associated with a suppressed expression of inflammatory markers, induced expression of adiponectin, and increased levels of phosphorylated ERK and AKT. To elucidate the molecular mechanism of sulfuretin in adipocytes, we performed microarray analysis and identified activating transcription factor 3 (Atf3) as a sulfuretin-responsive gene. Sulfuretin elevated Atf3 mRNA and protein levels in white adipose tissue and adipocytes. Consistently, deficiency of Atf3 promoted lipid accumulation and the expression of adipocyte markers. Sulfuretin's but not resveratrol's anti-adipogenic effects were diminished in Atf3 deficient cells, indicating that Atf3 is an essential factor in the effects of sulfuretin. These results highlight the usefulness of sulfuretin as a new anti-obesity intervention for the prevention of obesity and its associated metabolic diseases.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.889-903
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• 2018

The purposes of this study were to classify consumer types and to analyze purchase behavior depending on food safety attitudes related to the Fukushima nuclear accident. Based on the consumer survey data, factor analysis and cluster analysis were done to classify consumer types. Applying factor analysis, six factors with a total variance of 73.4% were extracted from 22 basic variables. The 6 factors were termed 'anxiety from ingesting agricultural and fishery products after the nuclear accident', 'importance of food safety when purchasing food', 'reduced rate of purchases of agricultural and fishery products after the accident', 'importance of food prices', 'socio-demographic characteristics' and 'family composition'. Using cluster analysis, consumers were classified into 5 types using the factor scores of 6 factors. The main results are as follows. For every consumer type, the anxiety about imported agricultural and fishery products was higher than that for domestic products after the nuclear accident. The food safety attitudes of consumers were mainly formed by the socio-demographic characteristics. Consumer types with high-education and high-income responded flexibly to the food safety concerning the accident; especially, the consumer type with a high-income and kids under 19 responded very reasonably to the accident. However, consumer types with a low-income and aged over 50 or less than 30 years were the least responsive to the accident, mainly due to financial restrictions. Thus, we suggest some food safety strategies and policy implications based on consumer type for food safety after the accident.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.3
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• pp.65-78
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• 2023

Objective : In this study, we aimed to investigate the effectiveness of family-centered intervention conducted with caregivers of children with autism spectrum disorder (ASD) in South Korea through a systematic literature review. Methods : Previous studies published from 2011 to 2021 were searched through RISS, KISS, and DBpia. The search terms applied included "autism spectrum" OR "general developmental disorder" OR "high-functioning autism" OR "Asperger's" AND "parent education" OR "family-centered intervention" OR "parent coaching" OR "parent training" OR "family participation." A total of 11 experimental studies were chosen based on the selection criteria. Results : According to the findings on the general characteristics of the study participants, intervention strategies, and effects of the intervention, it was observed that the majority of children with ASD who participated in the study were preschool-aged, and the majority of participating caregivers were mothers. The effects of family-centered interventions were evident in both children and parents. In children, the most significant effects were observed in interaction and communication skills. In parents, a reduction in parenting stress and an improvement in parenting efficacy were observed. The intervention strategies employed in the study varied, with sensory integration intervention, responsive communication, and interaction-centered intervention being the most commonly used, followed by developmental-centered intervention, positive behavior support (PBS), and parent-mediated intervention based on pivotal response treatment (PRT). Conclusion : The results of this study are significant in that they confirm that family-centered intervention is effective not only in improving the functioning of children with autism spectrum disorder, but also in reducing parenting stress and enhancing parenting efficacy, and provide evidence for clinical use.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.145-154
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• 2004

The growing demand for customer-responsive, made-to-order manufacturing is stimulating the need for improved dynamic decision-making processes in commercial fleet operations. Moreover, the rapid growth of electronic commerce through the internet is also requiring advanced and precise real-time operation of vehicle fleets. Accompanying these demand side developments/pressures, the growing availability of technologies such as AVL(Automatic Vehicle Location) systems and continuous two-way communication devices is driving developments on the supply side. These technologies enable the dispatcher to identify the current location of trucks and to communicate with drivers in real time affording the carrier fleet dispatcher the opportunity to dynamically respond to changes in demand, driver and vehicle availability, as well as traffic network conditions. This research investigates key aspects of real time dynamic routing and scheduling problems in fleet operation particularly in a truckload pickup-and-delivery problem under various settings, in which information of stochastic demands is revealed on a continuous basis, i.e., as the scheduled routes are executed. The most promising solution strategies for dealing with this real-time problem are analyzed and integrated. Furthermore, this research develops. analyzes, and implements hybrid algorithms for solving them, which combine fast local heuristic approach with an optimization-based approach. In addition, various partitioning algorithms being able to deal with large fleet of vehicles are developed based on 'divided & conquer' technique. Simulation experiments are developed and conducted to evaluate the performance of these algorithms.

• The Korean Journal of Cytopathology
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• v.17 no.2
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• pp.120-125
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• 2006

Distinguishing small cell carcinoma from other lung malignancies is of great clinico-therapeutic significance. Small cell carcinoma is an aggressive tumor with a tendency to metastasize early. Survival time if untreated is low but this tumor is highly responsive to chemotherapy. We have occasionally experienced difficulties in differentiation between adenocarcinoma and small cell carcinoma of the lung in fine needle aspiration cytology (FNAC). The aim of this study was to investigate the possibility of distinguishing small cell carcinoma from adenocarcinoma of the lung in FNAC. We evaluated cytomorphological features of FNAC specimens from 62 small cell carcinomas and 57 adenocarcinomas from the lung that were confirmed by biopsy and/or immunohistochemistry on cell block. Cytomorphological details of the two tumors were compared. Nuclear smearing and nearly absent cytoplasm were the most distinct findings in small cell carcinoma compared to adenocarcinoma (p<0.05). Necrotic background, architecture and chromatin pattern, nuclear molding and nucleoli were significantly different (p<0.05). Nuclear size, nuclear membrane nature and nuclear size variation however were not helpful in distinguishing the two tumors. Combining several features described above, small cell carcinoma can be properly differentiated from adenocarcinoma on FNAC. FNAC is proposed as a diagnostic tool of small cell carcinoma of the lung in the case of inaccessibility to biopsy, and so may allow the proper therapeutic strategies to be determined in such cases

• Korean Journal of Childcare and Education
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• v.9 no.2
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• pp.215-238
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• 2013

This study examined the effects of mothers' rejective parenting, emotional expressivity, children's emotional regulation strategy on their social withdrawal. Participants were 223 children(121 boys, 102 girls; recruited from classes with 4-5 year olds), their mothers and 20 child care teachers. The teachers completed rating scales to measure the children's social withdrawal and emotional regulation strategies. Mothers reported their rejective parenting along with emotional expressivity. The collected data were analyzed using descriptive statistics, Pearson's productive correlation coefficient, and hierarchical multiple regressions. Results showed that mothers' rejective parenting, children's venting/support seeking strategy and avoidance/non-responsive strategy had positive relation to, whereas mother's positive expressivity were negatively related to their social withdrawal. Hierarchical regression analysis indicated that the interaction of mother's rejective parenting and positive expressivity predicted children's social withdrawal. Mother's rejective parenting was associated with children's social withdrawal, especially for children with the lowest level of mother's positive expressivity. In addition, the association between mother's rejective parenting and children's social withdrawal were partially mediated by their venting/support seeking strategy.

• Journal of Gifted/Talented Education
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• v.24 no.3
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• pp.359-377
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• 2014

The purpose of this study is to investigate the problems and conditions of educational guidance and counselling of teachers in the gifted classes. For the study, 267 teachers were sampled from the Gifted Education Institutes of metropolitan and provincial offices of education and Gifted Classes of the school across Korea, and the questionnaire developed by the researchers were administered to them. The results of this study are as follows : First, the 82% of respondents reported that the guidance and counselling in the gifted education is needed. So it demands the active responsive strategies on it. Second, the respondents reported that the selfish or self-centered traits of the gifted students are the most problematic in the gifted classes. It shows the emphasis should be put on the basic life habits and moral education in the guidance and counselling of the gifted education. Third, they pointed out the case-based education is needed for the parents of the gifted to correct their misconceptions about their children. Fourth, to support the teachers of the gifted program, the administrative measures have to be taken, like operation of character education program, forming a consultative group with the experienced teachers, developing the case-based guideline for the guidance and counselling for the gifted education, etc. Fifth, we should develop the Korean model of the gifted education to promote social capital for our future society.

• Korean Journal of Psychosomatic Medicine
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• v.16 no.2
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• pp.69-74
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• 2008

Delirium is an organic psychiatric syndrome characterized by an acute onset, prominent disturbance of consciousness and cognitive impairment with fluctuating course. Although there is not a clear consensus concerning the optimal classification system for delirium subtypes, Lipowski(1983) firstly classified delirium by psychomotor activity, namely hyperactive, hypoactive, and mixed. According results of several following studies, prevalence of hypoactive delirium were not less than that of hyperactive delirium. But a diagnosis of hypoactive delirium often missed, which is most frequently misdiagnosed as depression and dementia. Hyperactive delirium can be caused by alcohol or benzodiazepine withdrawal, would be related with excessive dopamine and cholinergic deficiency, and is more responsive to high-potency antipsychotics therapy. Hypoactive delirium would be caused by metabolic encephalopathy, and tends to present a less responsiveness to antipsychotics and poorer overall prognosis with a prolonged duration of admission than hyperactive delirium. Delirium is not a homogenous syndrome. Because of different subtypes, it may have dissimilar underlying pathogenetic pathways. So different treatment strategies between various subtypes may be needed.

• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.241-265
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• 2023

A corporate insolvency prediction model serves as a vital tool for objectively monitoring the financial condition of companies. It enables timely warnings, facilitates responsive actions, and supports the formulation of effective management strategies to mitigate bankruptcy risks and enhance performance. Investors and financial institutions utilize default prediction models to minimize financial losses. As the interest in utilizing artificial intelligence (AI) technology for corporate insolvency prediction grows, extensive research has been conducted in this domain. However, there is an increasing demand for explainable AI models in corporate insolvency prediction, emphasizing interpretability and reliability. The SHAP (SHapley Additive exPlanations) technique has gained significant popularity and has demonstrated strong performance in various applications. Nonetheless, it has limitations such as computational cost, processing time, and scalability concerns based on the number of variables. This study introduces a novel approach to variable selection that reduces the number of variables by averaging SHAP values from bootstrapped data subsets instead of using the entire dataset. This technique aims to improve computational efficiency while maintaining excellent predictive performance. To obtain classification results, we aim to train random forest, XGBoost, and C5.0 models using carefully selected variables with high interpretability. The classification accuracy of the ensemble model, generated through soft voting as the goal of high-performance model design, is compared with the individual models. The study leverages data from 1,698 Korean light industrial companies and employs bootstrapping to create distinct data groups. Logistic Regression is employed to calculate SHAP values for each data group, and their averages are computed to derive the final SHAP values. The proposed model enhances interpretability and aims to achieve superior predictive performance.