• Journal of the Korean Regional Science Association
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• v.39 no.3
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• pp.35-48
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• 2023

This study analyzed the inflow factors of Yangjae Citizen's Forest Park using social big data generated online. To this end, the applicability of the emotional information analysis method is to be confirmed as a method of analyzing the perception of the city park and confirming the difference in the characteristics and use of the park. The analysis is based on big data, and as the core of the study is keyword network analysis, the methodology of the 'emotional information analysis method' patented by the author was applied. As a result of the analysis, among the influx factors of Yangjae Citizens' Forest recognized by citizens, the most positive emotional factor was derived as a factor related to 'park contents', and the negative emotional factor was derived as a factor related to 'park management'. These research results suggest that more in-depth program development and operation are needed to discover 'park contents' when implementing urban park revitalization support projects in the future

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.231-238
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• 2023

For boost PFC (Power Factor Correction) converters, various control methods are being studied to achieve unity power factor and low THD (Total Harmonic Distortion) of AC input current. Among them, average current mode control, which controls the average value of the inductor current to follow the current reference, is the most widely used. However, nowadays, as advanced digital control becomes possible with the development of digital processors, predictive control of boost PFC converters is receiving attention. Predictive control is classified into predictive current mode control, which generates duty in advance using a predictive algorithm, and model predictive current control, which performs switching operations by selecting a cost function based on a model. Therefore, this paper simply explains the average current mode control, predictive current mode control, and model predictive current control of the boost PFC converter. In addition, current control under entire load and disturbance conditions is compared and analyzed through simulation.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.93-102
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• 2024

The purpose of this study is examine the validity of digital competency indicators in order to develop a tool that can measure the digital competency of preschool teachers. To review the validity, exploratory factor analysis and confirmatory factor analysis were conducted on the data of 272 preschool teachers. The exploratory factor analysis resulted in four factors, and the confirmatory factor analysis verified the fit, validity(convergent validity, discriminant validity) and reliability of each competency group and the model composition of sub-competency indicators. The four factors validated were named 'Understanding Digital Technologies', 'Digital Technology Understanding', 'Digital Technology Application', 'Digital Technology-based Communication', 'Digital Ethics Understanding and Practice'. The analysis results demonstrated the reliability and validity of the tool for measuring the digital competencies of preschool teachers, and it is meaningful in that it can provide a foundation for measuring the digital competency of preschool teachers and conducting education program suitable for each digital competency level.

• BMB Reports
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• v.57 no.2
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• pp.98-103
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• 2024

The mammalian sirtuin family (SIRT1-SIRT7) has shown diverse biological roles in the regulation and maintenance of genome stability under genotoxic stress. SIRT7, one of the least studied sirtuin, has been demonstrated to be a key factor for DNA damage response (DDR). However, conflicting results have proposed that Sirt7 is an oncogenic factor to promote transformation in cancer cells. To address this inconsistency, we investigated properties of SIRT7 in hepatocellular carcinoma (HCC) regulation under DNA damage and found that loss of hepatic Sirt7 accelerated HCC progression. Specifically, the number, size, and volume of hepatic tumor colonies in diethylnitrosamine (DEN) injected Sirt7-deficient liver were markedly enhanced. Further, levels of HCC progression markers and pro-inflammatory cytokines were significantly elevated in the absence of hepatic Sirt7, unlike those in the control. In chromatin, SIRT7 was stabilized and colocalized to damage site by inhibiting the induction of γH2AX under DNA damage. Together, our findings suggest that SIRT7 is a crucial factor for DNA damage repair and that hepatic loss-of-Sirt7 can promote genomic instability and accelerate HCC development, unlike early studies describing that Sirt7 is an oncogenic factor.

• Anxiety and mood
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• v.20 no.1
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• pp.17-26
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• 2024

Objective : The objective of this study is to create questionnaires for Social Capital (SCQ) and Built Environment (BEQ) that can be utilized as protective factors for mental health. Methods : A total of 426 adults aged 18 or older, residing in 'D' Metropolitan City in Korea, were included as subjects in this study. Data for subjective evaluation of social capital and built environment were collected through an online survey. Various statistical analyses, such as reliability analysis, exploratory factor analysis, confirmatory factor analysis, and correlation analysis between PHQ-9 and GAD-7, were conducted. Results : The Cronbach's α values for SCQ and BEQ were 0.94 and 0.90, respectively, indicating good reliability. Exploratory factor analysis revealed that SCQ consisted of 4 factors, explaining a total of 71.91%, while BEQ consisted of 4 factors, explaining a total of 62.18%. Confirmatory factor analysis confirmed that both questionnaires had a reasonable configuration, with TLI, CFI, and RMSEA values at an appropriate level. Additionally, both SCQ and BEQ showed negative correlations with depression and anxiety. Conclusion : This study has developed a tool for measuring social capital and the built environment in Korea. It also demonstrates the reliability and validity of this questionnaire. The use of this tool could greatly support preventive mental health interventions within the community.

• International Journal of Oncology
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• v.54 no.6
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• pp.2117-2126
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• 2019

Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine that functions as a growth suppressor in normal epithelial cells and early stage tumors, but acts as a tumor promoter during malignant progression. However, the molecular basis underlying the conversion of TGF-β1 function remains largely undefined. X-linked inhibitor of apoptosis-associated factor 1 (XAF1) is a pro-apoptotic tumor suppressor that frequently displays epigenetic inactivation in various types of human malignancies, including colorectal cancer. The present study explored whether the anti-apoptotic effect of TGF-β1 is linked to its regulatory effect on XAF1 induction in human colon cancer cells under stressful conditions. The results revealed that TGF-β1 treatment protected tumor cells from various apoptotic stresses, including 5-fluorouracil, etoposide and γ-irradiation. XAF1 expression was activated at the transcriptional level by these apoptotic stresses and TGF-β1 blocked the stress-mediated activation of the XAF1 promoter. The study also demonstrated that mitogen-activated protein kinase kinase inhibition or extracellular signal-activated kinase (Erk)1/2 depletion induced XAF1 induction, while the activation of K-Ras (G12C) led to its reduction. In addition, TGF-β1 blocked the stress-mediated XAF1 promoter activation and induction of apoptosis. This effect was abrogated if Erk1/2 was depleted, indicating that TGF-β1 represses XAF1 transcription through Erk activation, thereby protecting tumor cells from apoptotic stresses. These findings point to a novel molecular mechanism underlying the tumor-promoting function of TGF-β1, which may be utilized in the development of a novel therapeutic strategy for the treatment of colorectal cancer.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.5
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• pp.403-419
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• 2024

Advance rate significantly affects both the construction period and cost in tunnel blasting. As such, there has been persistent research dedicated to the development of innovative blasting technique aimed at enhancing the advance rate. This paper aims to provide fundamental insights into the differences in advance rate and the powder factor between two- and three-free-face blasting, laying the groundwork for the advancement of tunnel blasting techniques. Large-scale cement mortar specimens were fabricated, and blasting tests were conducted for both two- and three-free-face blasting. Experimental findings were then compared with those from numerical simulation. Notably, an increase in the number of free faces, under uniform conditions, significantly improved the advance rate while reducing the powder factor. The outcomes of this study serve as crucial groundwork for devising blasting patterns employing three-free-face blasting, characterized by improved advance rates and minimized powder factors. Consequently, the anticipated outcomes include an overall improvement in tunnel advance rates and a reduction in the number of drilling holes and the amounts of explosives.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.683-687
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• 2001

Objective : Angiogenesis, the proliferation of capillary endothelial cells, is a vital component in the development, progression, and metastasis of many human tumors. Vascular endothelial growth factor(VEGF) is an endothelial cell-specific mitogen and induces angiogenesis and vascular permeability. The features of glioblastoma, distinct from low grade astrocytomas, are the presence of necroses and vascular endothelial proliferation. In this study, we investigated VEGF expression in the different grades of astrocytomas and determined whether VEGF expression correlates with development of glioblastoma and progression of astrocytomas. Patients and Methods : Forty seven patients with astrocytic tumors(24 males and 23 females), aged 3 to 65 years, were evaluated. Immunohistochemical staining was carried out using labelled streptavidin biotin method and primary antibody was a antirabbit polyclonal Ab against N-terminus region of VEGF165(Oncogene research product, MA, USA). Immunoreactivity(IR) was classified into no IR(absent or a trace of stain), moderate IR and intense IR by level of staining amount and intensity. Results : Six pilocytic astrocytomas showed 3 no IR and 3 moderate IR, 10 astrocytomas showed 2 no IR, 6 moderate IR and 2 intense IR, 12 anaplastic astrocytomas showed I no IR, 7 moderate IR and 4 intense IR and 19 glioblastomas showed 1 no IR, 11 moderate IR and 7 intense IR. Immunoreactivity was significantly different between low and high grade of tumors but there was no significant difference between anaplastic astrocytomas and glioblastomas. Gemistocytic tumor cells represented the predominent VEGF-immunoreactive cell types, as compared with compactly-arranged small tumor cells. In glioblastomas VEGF IR was observed in both perinecrotic and vital tumor areas. Conclusion : VEGF seems to be a important angiogenic factor in anaplastic astrocytomas and glioblastomas and VEGF expression may contribute to neovascularization of human astrocytomas.

• Journal of Technology Innovation
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• v.19 no.1
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• pp.55-78
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• 2011

The social impact of science and technology is increasing, the meaning of technology assessment is not small in modern society, Specially, the technology assesment(TA) has been institutionalized and performed by Korean administration and its official results has reflected directly in the S&T policy. Therefore, the technology assesment is a device that prepare the negative effects of S&T and the social controversy in advance. To select the target technology of technology assessment will be done carefully in various perspective and concerned with the characteristics of technology assessment emphasizing social assessment, the institutional system of selecting one technology in each year and the contents and methods of evaluation that are determined in accordance with technology characteristics. However, the method of selecting target technology in TA is mostly peformed by qualitative discussion and vote rather than by reflecting various opinion and understanding TA until now. In this paper, we developed the indicator has to be considered to select target technology for TA by using factor analysis. Developed indicator is consist of five factor, such as the need for social consensus and the size of social/cultural impact etc., and we weight each factor by using Analytic Hierarchy Process(AHP). Futhermore, we show the example how to applicate directly these indicator and weights to select target technology and suggest institutional application in TA. Though using developed indicator in this paper, we expect to select appropriate technology for institutional TA and the application of TA results in society and public policy can be strengthened.

• Journal of Korean Society of Rural Planning
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• v.13 no.2
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• pp.63-74
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• 2007

This study aims to develop rural house maintenance technique by researching and analyzing the demand for rural house by urban retirees or urbanites who are planning to retire. The target for the survey consisted of urban retirees or urbanites who are planning to retire at the ages between 40 and 65, and were divided into group A, the attendants in rural-related education, and group B, the non-attendants in rural-related education. The contents of the survey included the plan and purpose for rural settlement, the utilization form or residential form of rural house and its expected size, necessary in-house facilities, necessary community facilities, improvement and maintenance factors of rural house, political and legal support for the application of rural house maintenance, etc. The results findings of this study are as follows; 1)For both group, the major purpose of rural settlement appeared to be 'for rural life', utilization form of rural house to be 'acquired ownership or use of empty house', residential form to be 'cohabitation', expected size to be 'under $20{\sim}30$ pung', and expenditure to be 'under $50{\sim}100\;million$'. 2)Most wanted necessary in-house facilities included backyard, multipurpose storage room for group A, and backyard, garden for group B. Necessary community facilities included boardwalk, sewage disposal unit for group A, and boardwalk, shop for group B. 3)Improvement factor for rural house showed 'poor insulation' as first factor for both groups, and for maintenance factor, 'backyard', 'under-floor heating' for group A, and 'environmental-friendly materials', 'backyard' for group B. 4)Most wanted overall political and legal support included 'support on land and real estate supply' for group A, and 'medical and transportation service' for group B. For both group, most wanted support when purchasing a house included 'provision of information on house and realestate purchase', and for legal support, 'legal support for guaranteed house and maintenance' as first factor. The results of this study could be utilized to restructure the rural residence, which would meet the diverse demand of both rural residents and urbanites by providing an opportunity for urbanites to enjoy rural life.