• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.461-467
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• 2021

Among the defect factors that can occur when a wafer-level lens is molded using a thermosetting material, the mold sticking problem of a molded lens during the release process can damage the molded substrate and deform the substrate at the wafer level. An experiment was conducted to examine the factors affecting the demolding force in the lens forming process. The demolding force was examined according to the coating material of the molds. The mold was surface-treated with ITO and Ti, followed by plasma treatment in an O2 atmosphere. A DLC coating was then performed, and the curing and releasability were examined. A coating method for the pull-off experiment was selected based on the results. To measure the demolding force according to the curing process conditions, a method of curing at a constant pressure and a method of curing at a constant position were applied. As a result, the TiO2 surface treatment reduced the release force. When cured by controlling the location, curing shrinkage can reduce the adhesion energy of the interface during curing, resulting in better demolding.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.6
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• pp.81-94
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• 2020

Based on innovative technologies and new start-up ideas, startups have been actively researched on the entrepreneurship needed to strengthen the organization's capabilities and generate results in the start-up process. This study studied the entrepreneurial orientation on the performance of startups in the Philippines and the financial and non-financial performance of enterprises. This study carried out not only the entrepreneurial orientation to the performance of Filipino startups but also the role of social capital as parameters in the performance of enterprises. The empirical research was completed for 93 Philippine startups and the suitability of the research model was evaluated with a PLS-based structural equation model. The results of the study first confirmed that the enterprise orientation of Philippine startups has a positive impact on both financial and non-financial performance of the enterprises. Second, the entrepreneurial orientation of Philippine startups has been shown to have a positive effect on both the structural, cognitive and relational dimensions of social capital. Third, it was found that the relevant dimensions of social capital mediated both the corporate orientation and the relationship between the financial and non-financial performance of the entity. Entrepreneurial orientation has been confirmed to be directly or indirectly affecting the performance of startups through social capital. These findings reaffirmed that entrepreneurial orientation is still a valid important factor in developing countries as well as in countries such as Korea and the United States. Based on this study, we have identified the need for research from a more integrated perspective, such as the concept of strategic orientation. Finally, practical implications were presented to reflect the findings analyzed.

• Journal of The Korean Association of Information Education
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• v.25 no.2
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• pp.227-237
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• 2021

In this thesis, a survey was conducted on elementary school teachers about the establishment of information subjects in elementary schools. As a result, the opinion that information subjects should be newly established for ICT literacy education and SW/AI education in elementary schools was very high. In addition, if it is difficult to establish a new information subject, opinions in favor of the organization of the information subject as an autonomous subject using the discretionary time of the principal were high. In light of the results of this analysis, it is judged that it is necessary to establish a new information subject for ICT literacy education and SW/AI education in the next elementary school curriculum. However, if it is difficult to establish a new information course, it is necessary to come up with a plan that can be operated in the form of autonomous subject for students wishing to learn SW/AI. And it is judged that the number of class hours should be secured for at least 1 hour or 2 hours per week in the 3rd grade and above.

• Journal of The Korean Association of Information Education
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• v.25 no.2
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• pp.239-247
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• 2021

In elementary schools, software education became essential and the importance of artificial intelligence education was emphasized. The software private education market is gradually growing, but related research is insufficient. In addition to the software education provided by public education, a basic investigation and analysis on the reasons and perceptions of parents participating in software private education are required. This study surveyed the reasons and necessity of participating in software private education, and perceptions of software education for parents of elementary school students who participated in software private education. As a result of the study, the biggest reason for participating in software private education was the lack of time and environment to provide software education in elementary schools. It was analyzed that the need for private software education had the greatest impact on the need for a separate formal subject for software education.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.32 no.4
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• pp.137-143
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• 2021

Objectives: Despite the growing concern regarding the adverse effects related to problematic smartphone use (PSU), little is known about underlying morphologic changes in the brain. The brainstem is a deep brain structure that consists of several important nuclei associated with emotions, sensations, and motor functions. In this study, we sought to examine the difference in the volume of brainstem substructures among adolescents with and without PSU. Methods: A total of 87 Korean adolescents participated in this study. The PSU group (n=20, age=16.2±1.1, female:male=12:8) was designated if participants reported a total Smartphone Addiction Proneness Scale (SAPS) score of ≥42, whereas the remaining participants were assigned to the control group (n=67, age=15.3±1.7, female:male=19:48). High-resolution T1 magnetic resonance imaging was performed, and the volume of each of the four brainstem substructures [midbrain, pons, medulla, and superior cerebellar peduncle (SCP)] was measured. Analysis of covariance was conducted to reveal group differences after adjusting for effects of age, gender, whole brainstem volume, depressive symptoms, and impulsivity. Results: The PSU group showed a significantly smaller volume of the SCP than the control group (F=8.273, p=0.005). The volume of the SCP and the SAPS score were negatively correlated (Pearson's r=-0.218, p=0.047). Conclusion: The present study is the first to reveal an altered volume of the brainstem substructure among adolescents with PSU. This finding suggests that the altered white matter structure in the brainstem could be one of the neurobiological mechanisms underlying behavioral changes in PSU.

• Parasites, Hosts and Diseases
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• v.60 no.4
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• pp.241-246
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• 2022

Felids are the unique definitive host of Toxoplasma gondii. The intestine of felid is the only site for initiating Toxoplasma gondii sexual reproduction. T. gondii excretes millions of infectious oocysts from the intestine, which are the primary source of infection. There are many difficulties in developing vaccines and drugs to control oocyst excretion due to the lack of an appropriate experimental model. Here, we established an in vitro feline intestinal epithelial cell (IEC) infection system and an efficient animal model of T. gondii Chinese 1 genotype, Wh6 strain (TgCtwh6). The Kunming mice brain tissues containing TgCtwh6 cysts were harvested 42-day post-infection. The bradyzoites were co-cultured with cat IECs in vitro at a ratio of 1:10. Five 3-month-old domestic cats were orally inoculated with 600 cysts each. The oocysts were detected by daily observation of cat feces by microscopy and polymerase chain reaction. We found that the parasite adhered and invaded cat IECs in vitro, transformed into tachyzoites, and then divided to form rose-like structures. These parasites eventually destroyed host cells, escaped, and finished the asexual reproduction process. Schizonts associated with sexual reproduction have not been observed during development in vitro cultured cells. However, schizonts were detected in all infected cat intestinal epithelial cells, and oocysts were presented in all cat feces. Our study provides a feasible cell model and an efficient infection system for the following studies of T. gondii sexual reproduction, and also lays a foundation to develop drugs and vaccines for blocking excretion and transmission of oocysts.

• Journal of agricultural medicine and community health
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• v.47 no.4
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• pp.220-228
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• 2022

Objective: glucometer is one of POCT(point-of-care testing) devices used by EMS. Accurate measurement value is important for patient decision making. Quality control is necessary for this, but most EMS are still using glucometer without quality control it. Therefore, management status and quality control status of glucometers used by 119 paramedics waswere investigated. Methods: 6 and 8 of glucometers and blood glucose test strips were submitted from 4 safety centers in 2010 and 8 safety centers in 2012, respectively. Glucometers submitted by local safety centers were analyzed in 2010 and 2012. The control glucometer, which was well managed at A University Hospital, was assumed to be accurate for at blood glucose measurement. Glucose values of various quality control materials control solutions were measured and analyzed using linear regression and Pearson's correlation test. Error rates were obtained via error tolerance range required by the 2011 ISO(International Organization for Standardization) guideline. For statistics, Excel and MedCalC programs were used. Results: mong 14 safety centers in the region, 4 centers(28.5%) in 2010 and 8 centers(57.1%) in 2012 submitted 6 and 8 glucometers. In the first evaluation in 2010, 2 out of 6(33.3%) glucometers were untestable due to error, and 45 out of 6(66.683.3%) blood glucose test strips' validity were expired. In the second evaluation in 2012, 1 out of 8(13.5%) glucometers were untestable due to lack of battery, and 2 out of 8(25%) blood glucose test strips' validity were expired. All correlation coefficients were above 0.989 in 2010 and above 0.997 in 2012. Error rates were generally high when using expired blood glucose test strips. Conclusion: Among 119 paramedics' guideline, quantity and operation status of POCT devices are well managed, but quality control is not. Therefore, it is necessary to add management status and quality control status of POCT devices to the EMS' field work guideline.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.315-324
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• 2022

Objective : The aim of this study was to verify the equivalence and effectiveness of the tablet-administered Korean Repeatable Battery for the Assessment of Neuropsychological Status (K-RBANS) for the prevention and early detection of dementia. Methods : Data from 88 psychiatry and neurology patient samples were examined to evaluate the equivalence between tablet and paper administrations of the K-RBANS using a non-randomly equivalent group design. We calculated the prediction scores of the tablet-administered K-RBANS based on demographics and covariate-test scores for focal tests using norm samples and tested format effects. In addition, we compared the receiver operating characteristic curves to confirm the effectiveness of the K-RBANS for preventing and detecting dementia. Results : In the analysis of raw scores, line orientation showed a significant difference (t=-2.94, p<0.001), and subtests showed small to large effect sizes (0.04-0.86) between paper- and tablet-administered K-RBANS. To investigate the format effect, we compared the predicted scaled scores of the tablet sample to the scaled scores of the norm sample. Consequently, a small effect size (d≤0.20) was observed in most of the subtests, except word list and story recall, which showed a medium effect size (d=0.21), while picture naming and subtests of delayed memory showed significant differences in the one-sample t-test. In addition, the area under the curve of the total scale index (TSI) (0.827; 95% confidence interval, 0.738-0.916) was higher than that of the five indices, ranging from 0.688 to 0.820. The sensitivity and specificity of TSI were 80% and 76%, respectively. Conclusion : The overall results of this study suggest that the tablet-administered K-RBANS showed significant equivalence to the norm sample, although some subtests showed format effects, and it may be used as a valid tool for the brief screening of patients with neuropsychological disorders in Korea.

• Korean Journal of Biological Psychiatry
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• v.29 no.1
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• pp.22-31
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• 2022

Objectives Recently, weight loss has emerged as a national concern in South Korea, and this has resulted in an increase in the frequency of use of central nervous system (CNS)-stimulating appetite suppressants. This study aimed to collect cases of psychotic disorders and bipolar disorders triggered by phentermine and phendimetrazine and explore the clinical features and courses. Methods In this retrospective study, we analyzed the electronic medical records of patients and selected eight patients who developed psychotic symptoms and manic symptoms for the first time after taking phentermine and phendimetrazine. All cases were reviewed, and their clinical features and course were summarized. Results All eight patients developed psychotic symptoms, and one had accompanying manic symptoms. The final diagnosis was appetite-suppressant-induced psychotic disorder in four patients, schizophrenia in three, and appetite-suppressant-induced bipolar disorder in one. In addition, three patients were diagnosed as having substance-use disorder. The key psychotic symptoms of these patients were hallucinations and paranoia. Conclusions These case findings suggest that phentermine and phendimetrazine can cause psychotic disorder, bipolar disorder, or substance use disorder and that medical professionals and the public should practice caution when prescribing and using these drugs.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.177-187
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• 2022

This study estimates the design wave in the event of a typhoon attack at Busan new port using the wind field, the revised shallow water design wave estimation method proposed by the Ministry of Oceans and Fisheries in 2020, and proposed a reliable method of calculating the shallow water design through verification with the wave observation data. As a result of estimating typhoon wave using the wind field and SWAN numerical model, which are commonly used in the field work, for typhoon that affected Busan new port, it was found that reproducibility was not good except typhoons KONG-REY(1825) and MAYSAK(2009). In particular, in the case of typhoon MAEMI(0314), which had the greatest impact on Busan new port, the maximum significant wave height was estimated to be about 35.0% smaller than that of the observed wave data. Therefore, a plan to improve the reproducibility of typhoon wave was reviewed by applying the method of correcting the wind field and the method of using the Boussinesq equation numerical model, respectively. As a result of the review, it was found that the reproducibility of the wind field was not good as before when the wind field correction. However as a method of linking wind field data, SWAN model results, and Boussinesq numerical model, typhoon wave was estimated during typhoon MAEMI(0314), and the maximum significant wave was similar to the wave observations, so it was reviewed to have good reproducibility.