• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.184-190
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• 2016

Objectives : This study analyzed the differences of body mass index(BMI) in Korean patients with Alzheimer's diseases(AD), Mild Cognitive Impairment(MCI), and healthy controls to verify whether low BMI is associated with cognitive impairment. Furthermore, this study also sought to examine any association between BMI and Mini Mental State Examination-Korean version(MMSE-K), Clinical Dementia Rating(CDR), and Global Deterioration Scale(GDS). Methods : A total of 257 subjects were included in the study. History taking, mental status examination, physical examination and neurocognitive function test were carried out for the diagnosis of AD and MCI. The subjects' demographic data and presence of diseases were also surveyed. The overall cognitive function and severity of diseases were assessed using MMSE-K, GDS, and CDR. Results : The order of BMI was found to be healthy controls>MCI>AD, with statistically significant differences among the groups. The order of MMSE-K scores was similar, with healthy controls>MCI>AD in statistically significant differences. The healthy controls had the lowest CDR and GDS scores, and AD patients had the highest scores. There was a significant positive correlation between BMI and MMSE scores(r=0.238, p=0.000). BMI was negatively correlated with CDR(r=-0.174, p=0.008) as well as with GDS(r=-0.233, p= 0.000). Conclusions : Measuring BMI of patients with AD or MCI is expected to be meaningful in that BMI could be a clinical indicator of AD. We expect this to be beneficial for the diagnosis, prevention, and therapeutic approach of AD and also expect large-scale, long-term longitudinal studies to follow.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.83-93
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• 2016

Objectives : The Center for Epidemiologic Studies Depression scale-Revised is a recently revised scale which has been reported as a valid tool for the assessment of depressive symptoms. It encompasses cardinal symptoms of depression described in the Diagnostic and Statistical Manual of Mental disorders, fourth edition. In this study, we assessed the reliability, validity and psychometric properties of the Korean version of the CESD-R(K-CESD-R). Methods : Forty-eight patients diagnosed as major depressive disorder, dysthymia, depressive disorder NOS according to the DSM-IV criteria using Mini International Neuropsychiatric Interview and 48 healthy controls were enrolled in this study. They were assessed with K-CESD-R, K-MADRS, PHQ-9, KQIDS-SR, STAI to check cross-validation. Statistical analyses were performed using calculation of Cronbach's alpha, Pearson correlation coefficient, Principal Component Analysis, ROC curve and optimal cut-off value. Results : The Cronbach's alpha of K-CESD-R was 0.98. The total score of K-CESD-R revealed significantly high correlations with those of K-MADRS, PHQ-9, KQIDS-SR(r=0.910, 0.966 and 0.920, p<0.001, respectively). Factor analysis showed two factors account for 76.29% of total variance. We suggested the optimal cut-off value of K-CESD-R as 13 according to analysis of the ROC curve which value sensitivity and specificity both equally. Conclusions : These Results showed that the K-CESD-R could be a reliable and valid scale to assess depressive symptoms. The K-CESD-R is expected as a useful and effective tool for screening and measuring depressive symptoms not only in outpatient clinic but also epidemiologic studies.

• Korean Journal of Psychosomatic Medicine
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• v.23 no.1
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• pp.47-56
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• 2015

Objectives:The aim of this study is to investigate any differences between non-medical and medical college students for : 1) a level and the nature of perceived stress, 2) a level of life satisfaction, and 3) the related factors affecting to life satisfaction. Methods:We measured self-reported questionnaires of stress, satisfaction with life, health behavior including happiness, alcohol use, nicotine dependency and depressive symptoms in 1,714(863 non-medical and 851 medical) college students. Results:Non-medical college students had significantly higher total stress scores than medical college students(${\chi}^2$=7.66, p<.001). In non-medical college students, employment problem score was significantly higher than medical college students(t=4.07, p<.001). In medical college students, the scores of academic achievement (t=-3.81, p<.001), change of social life(t=-2.03, p<.05), death(t=-2.05, p<.05) or sickness(t=-2.60, p<.05) of friends were significantly higher than non-medical college students. And non-medical college students showed significantly lower life satisfaction scores than medical college students(${\chi}^2$=-19.05, p<.001). We also found that life satisfaction were significantly related to happiness in non-medical college students(${\beta}$=.410, $R^2$=.325, p<.001) and depressive symptoms in medical college students(${\beta}$=-.435, $R^2$=.326, p<.001) by stepwise multiple regression analysis. Conclusions:In this study, a level and the nature of perceived stress, a level of life satisfaction, and the related factors affecting to life satisfaction showed definitely differences between non-medical and medical college students. We suggest with our findings that specified mental health promotion program need for the college student's mental health management.

• Korean Journal of Psychosomatic Medicine
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• v.23 no.1
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• pp.26-35
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• 2015

Objectives:The purpose of this study was to evaluate reliability and validity of the Korean version of the Postconcussional Syndrome Questionnaire(KPCSQ) which was originally developed in 1992 by Lees-Haley. Methods:Patients with traumatic brain injury were recruited from April 2009 to December 2011 from the Korean University Ansan Hospital. We selected patients that met the ICD-10 diagnostic criteria of postconcussional syndrome and organic mental disorder including organic mood disorder, organic emotionally labile disorder, organic anxiety disorder and organic personality disorder. The KPCSQ, Trait and State Anxiety Inventory(STAI-I, II), and Center for Epidemiologic Studies Depression Scale(CESD) were administered to all subjects. Factor analysis of the items were performed and test-retest correlation were evaluated. Internal consistency of the KPCSQ and its subscales was assessed with Cronbach's alpha. External validity of the KPCSQ were examined by correlation coefficient with the STAI-I, II, and CESD. Results:The Cronbach's alpha coefficient of the total PCSQ was 0.956. The test-retest reliability coefficient was 0.845. The PCSQ showed significant correlation with STAI-I, II and CESD. The factor analysis of the PCSQ yielded 4 factors model. Factor 1 represented 'affective and cognitive symptoms', factor 2 represented 'somatic symptoms', factor 3 represented 'infrequent symptoms' and factor 4 represented 'exaggeration or inattentive response'. There was no significant difference between the PCS group and the organic mental disorder group in the score on each measure. The scores on KPCSQ and its subscales in the subjects that had scored 5 or more in 'exaggeration or inattentive response' are significantly higher than those in the subjects had scored 4 in 'exaggeration or inattentive response'. Conclusions:This study suggests that the Korean version of PCSQ is a valid and reliable tool for assessing psychiatric symptomatology of patients with traumatic brain injury. Further investigations with greater numbers of subjects are necessary to assess the clinical usefulness of the KPCSQ.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.4
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• pp.25-58
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• 2021

This study investigated the corporate growth with more emphasis on longitudinal characteristics, not the results of companies with relatively more emphasis on cross-sectional, in the 21st-century entrepreneurial context. As of the end of 2019, sampled 479 global unicorn companies, and 333 high-growth companies with revenue of more than $100 million among 5,000 private companies in the U.S. with a compound annual growth rate (CAGR) exceeding 15% for the past three years. They were examined with 3 perspectives in terms of corporate growth that 1) the growth of enterprise value, 2) the pace of growth, and 3) the effectiveness of growth. As a result of our study, the corporate growth of the perspective of creating enterprise value had a relatively higher relationship with the characteristics of industries and markets. The pace of growth was more fully explained by the characteristics of the industry and the market environment and the choice of strategies that make up a valid combination. In addition, growth in terms of the effectiveness of corporate performance was influenced by the choice of strategy, the characteristics of the industry and market environment, and its business age, the proxy variable of resource accumulation, comprehensively. This study through a sample based on companies with an enterprise value of more than $1 billion and annual revenue of more than $100 million can be a valid reference in terms of creating milestones and roadmaps for scale-up of early-stage startups, particularly in terms of practitioners' point of view. It also provides a critical reference for overcoming the limitations of mainstream theories of the 20th century and developing the theory of corporate growth that fits the 21st-century entrepreneurial context.

• Economic and Environmental Geology
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• v.54 no.5
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• pp.535-547
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• 2021

Aggregate is an essential construction material, and the demand is increasing every year. Aggregate has different properties in each region, and it is difficult to supply it over long distances due to its quantity and weight. For the stabilization of aggregate supply and demand, regional aggregate resource surveys have been conducted since 1993 in Korea. In this study, an aggregate resource survey was conducted in Goyang City to understand the characteristics of aggregate distribution as part of the annual regional aggregate resource survey in 2020. Goyang City has a high mountainous area to the east, and the southwestern part shows a topography where a wide flatland develops. It has 18 small streams originated from the eastern mountainuos area and 1 large stream Han River. The drilling data shows that thickness of the Quaternary deposits tend to deepen toward the south. The aggregate reserves are relatively abundant, the depth of the aggregates are relatively deep. Changes in the depth of the Quaternary deposits and the amount of aggregate in Goyang are seems to be closely related to the activities of the Han River rather than the sedimentation characteristics from the upstream to the downstream of the small streams. This characteristics show a similar tendency to the distribution of aggregates in adjacent regions to the west coast in Korea. Therefore, the regions that close to west coast have a high probability of aggregate reserves around relatively large-scale streams flowing into the west coast.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.5
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• pp.394-402
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• 2021

The entry of an aging society and the extension of human life expectancy, the increasing interest in women's social advancement and men's appearance, and the natural interest in K-culture through media media, while receiving worldwide attention, Focus on K-Bueaty. Recently, looking at the occupation of the medical tourism field, in the case of aesthetic medicine tourism such as molding and dermatology, it has gained popularity not only in Asia such as China and Japan, but also in North America and Europe. The first external confirmation of human aging is the wrinkles on the skin of the face. Clean, wrinkle-free, elastic and healthy skin is a desire of most people. Skin condition and condition such as focused ultrasonic stimulation (HIFU: High Intensity Focused Utrasound) and low frequency, high frequency (RF: Radio Frequency), galvanic therapy using microcurrent, cryotherapy using rapid cooling, etc. Depending on the method of management, the effect of the treatment differs depending on the output and the stimulation site, etc., even in the treatment of medical equipment and beauty equipment using the same mechanism. In this research, in order to develop invasive high-frequency dermatological devices using a large number of beauty medical devices and microneedles of beauty devices, the international standards IEC 60601-2 (standards for individual medical devices) and MFDS (Ministry of) We designed and developed a high-frequency output device in compliance with the high-frequency stimulation standard announced in the Food and Drug Safety (Ministry of Food and Drug Safety). The circuit design consists of an amplifier (AMP: Amplifier) using Class-A Topology and a power supply device using Half-Bridge Topology. As a result of measuring the developed high-frequency output device, an average efficiency of 63.86% was obtained, and the maximum output was measured at 116.7W and 50.67dBm.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.2
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• pp.12-25
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• 2021

Objective : This study explored the effects of family-centered coaching using a sensory integration-based approach on the levels of performance and satisfaction for children with autism spectrum disorder (ASD). Methods : From April 16, 2020 to August 6, 2020, participants included 10 children with ASD, between the ages of three to six who met the inclusion criteria, and their guardians. I used the Canadian Occupational Performance Measure (COPM) to evaluate the children's levels of performance and satisfaction and the Goal Attainment Scaling (GAS) to evaluate their occupational performance. The experimental group (n=5) continued the sensory integration therapy while receiving their personalized family-centered coaching training for 60 minutes per week. This continued for four weeks via home visits and video calls. The control group (n=5) also continued to receive the sensory integration therapy while receiving sensory integration-based general counseling in relation to activity objectives. Results : Statistically significant differences were found in the scores of COPM performance and satisfaction and the GAS scores between the experimental group and the control group, before and after the intervention (p<.05). Statistically significant differences were found in score changes in COPM and GAS, between the two groups (p<.05). Cohen's d also showed a big effect size on the scores of COPM satisfaction (d=2.768) and the GAS scores (d=2.786). Conclusion : This study demonstrated that the sensory integration-based, family-centered coaching had more positive effects on the level of performance and satisfaction of children with ASD, than general counseling.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.4
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• pp.195-209
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• 2021

According to the 2019-2020 social media usage survey conducted by the Seoul e-commerce center, 5 out of 10 consumers have experienced shopping through social media. The cost of traditional advertising media has been reduced and advertising spending on social media has risen by 74%, indicating that social media is becoming a more important marketing element. While the number of users of social media has increased and corporate marketing activities have increased accordingly, research has been conducted in various aspects of marketing such as user motivation for social media, satisfaction, and purchase intention. There was no subdivided study on the differences in the social media usage frequency of consumers in actual purchasing behavior. This study attempted to identify differences in consumer characteristics by cluster in the agrifood purchase situation by grouping them by type according to the frequency of use of social media for consumers who purchase agri-food online. Product involvement, product need, and online purchase channel Consumer characteristics such as demographic distribution, perceived risk, and eating and lifestyle in each cluster were checked for the three agrifood purchase situations including choice, and types for each cluster were presented. To this end, questionnaire data on the frequency of social media use and online agrifood purchase behavior were collected from 245 consumers, and the validity of the measurement variables was secured through factor analysis and reliability analysis. As a result of cluster analysis according to the frequency of social media use, it was divided into three clusters. The first cluster was a group that mainly used open social media, and the second cluster was a group that used both open and closed social media and online shopping malls; The third cluster was a group with low online media usage overall, and the characteristics of each cluster appeared. Through regression analysis, the effect on product involvement, product need, and purchase channel selection when purchasing agri-food online through each of the three clusters was confirmed through regression analysis. As a result of the regression analysis, the characteristic of cluster 1 in the situation of purchasing agri-food online is a male in his 30s living in a rural area who has no reluctance to purchase agri-food on social media or online shopping malls. The characteristics of cluster 2 are mainly consumers who are interested in purchasing health food, and the consumer characteristics are represented. In the case of cluster 3, when purchasing products online, they purchase after considering quality and price a lot, and the consumer characteristics are represented as people who are more confident in purchasing offline than online. Through this study, it is judged that by identifying the differences in consumer characteristics that appear in the agri-food purchase situation according to the frequency of social media use, it can be helpful in strategic judgments in marketing practice on social media customer targeting and customer segmentation.

• Journal of Technology Innovation
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• v.29 no.3
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• pp.1-31
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• 2021

With the growing importance of technology innovation as a key factor for firms' competitive advantage, 'innovation persistence' became also an important research subject. 'Innovation Persistence' is a concept that indicates whether or not firms' innovation activity or performance continues. However, the data used for innovation studies are carried out as cross-sectional surveys in most countries. For this reason, studies dealing with longitudinal aspect of innovation persistence are rare. In particular, there is almost no research on innovation persistence using Korean innovation survey data. This study reviews the concepts and characteristics of innovation persistence based on extant literature, and perform an empirical analysis on the status and features of Korean firms' technology innovation persistence. Based on the data of the Korean Innovation Survey (KIS) conducted every other year from 2012 to 2018, panel data on 3,379 firms which observed multiple times are constructed. As a result, only part of the firms with persistent innovation were observed (for innovation performance 10~12%, for innovation activity 15~17%), and it was found that the persistence of non-innovation was remarkable(about 52~57%). And it was confirmed that the persistence of innovation activities is stronger than that of innovation performance. Besides, some features by sub-types of innovation appeared. Product innovation showed higher persistence than process innovation, and internal R&D also showed higher persistence than joint/external R&D. As a result of additional logit analysis to identify factors, it was found that radical or gradual product innovation is the most influential factor in persisting innovation in the next period. Since the sample selection bias due to a limitations of raw data might exist in the panel data constructed in this study, it should be noted that faulty generalization of the results are not allowed. Nevertheless, this is the first study to examine the technology innovation persistence targeting Korean firms and is expected to be a starting point for follow-up studies. It is anticipated that advanced research results will be drawn through the establishment of official panel data and improved methodologies.