• Journal of the Korea Institute of Building Construction
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• v.17 no.3
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• pp.287-294
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• 2017

Recently the construction project is becoming large-sized, complicated, and modernize. This has increased the uncertainty of construction risk. Therefore, studies should be followed regarding scientifically identifying the risk factors, quantifying the frequency and severity of risk factors in order to develop a model that can quantitatively evaluate and manage the risk for response the increased risk in construction. To address the problem, this study analyze the probability distribution of risk causes, the probability of occurrence and frequency of the specific risk level through Monte Carlo simulation method based on the accident data caused at construction sites. In the end, this study derives quantitative analysis by analyzing the amount of risk and probability distributions of accident causes. The results of this study will be a basis for future quantitative risk management models and risk management research.

• Korean Institute of Interior Design Journal
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• v.24 no.5
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• pp.117-127
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• 2015

This paper depicts a case study of the BIM (Building Information Modeling)-enabled evaluation of design alternatives for an actual remodeling project in Yeongwol, Korea. The increase of urban population and income followed by the growth of economy has derived massive supply of grand scale housing project in Korea since 1970s. Consequently, building remodeling became one of the feasible resolutions for renovating such old housings in these days. This paper aims to introduce a technical approach to such remodeling projects based on BIM-enabled applications focusing on quantitative analysis of design alternatives. Among the technical issues of such building remodeling projects, this paper focuses on the BIM-enabled area analysis and comparison between design alternatives to support decision-making even in early phase of remodeling design process. BIM and its variety of applications have broadly influenced the domain of AEC-FM (Architecture, Engineering, Construction, and Facility Management) within the lifecycle of buildings. As one of the applications facilitated by BIM, the automated area calculation and scenario-based comparison between alternatives can play an important role in the early phase of remodeling project. We modeled three design alternatives (buildings) and three housing modules (units) based on the actual case in Yeongwol city, Korea using a BIM design authoring tool. Nine combinatorial BIM models were demonstrated for the BIM-enabled review process described in this paper. To determine the most optimal design scenario among nine alternatives, this paper demonstrates a result of the conducted spatial program review. The main subject includes specific spatial program issues on; 1) the number of unit spaces; and 2) area of individual/grouped and private/shared spaces.

• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.9-16
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• 1999

Gas energy facilities which are located in urban areas have been shown as terrifying objects to the people who live nearby, because of increasing recent disastrous accidents. So, it is essential to develop a integrated safety management system including quantitative risk assessment in order to predict and to reduce the effect of gas accidents. In this study, the framework of synthesized QRA(Quantitative Risk Assessment) considering the recent situation and condition was established in order to provide proper models for analysing gas accidents. The deviation of LPG storage facilities was described and then supposed incident scenarios were provided. Procedures which could assess the risk of facilities according to incident scenarios were showed and the practical application of individual risk was suggested in order to represent the quantified risk. And, a user-friendly computer program was developed to implement these methods at the same time.

• Psychiatry investigation
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• v.15 no.11
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• pp.1087-1093
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• 2018

Objective Posttraumatic stress disorder (PTSD) is distinct from anxiety disorders in its etiology and clinical symptomatology, and was reclassified into trauma- and stressor-related disorders in DSM-5. This study aimed to find neurophysiological correlates differentiating PTSD from anxiety disorders using resting-state quantitative electroencephalography (qEEG). Methods Thirty-six patients with either PTSD or acute stress disorder and 79 patients with anxiety disorder were included in the analysis. qEEG data of absolute and relative powers and patients' medication status on the day of qEEG examination were obtained. Electrodes were grouped into frontal, central, and posterior regions to analyze for regional differences. General linear models were utilized to test for group differences in absolute and relative powers while controlling for medications. Results PTSD patients differed from those with anxiety disorders in overall absolute powers [F(5,327)=2.601, p=0.025]. Specifically, overall absolute delta powers [F(1,331)=4.363, p=0.037], and overall relative gamma powers [F(1,331)=3.965, p=0.047] were increased in PTSD group compared to anxiety disorder group. Post hoc analysis regarding brain regions showed that the increase in absolute delta powers were localized to the posterior region [F(1,107)=4.001, p=0.048]. Additionally, frontal absolute gamma powers [F(1,107)=4.138, p=0.044] were increased in PTSD group compared to anxiety disorder group. Conclusion Our study suggests increased overall absolute delta powers and relative gamma powers as potential markers that could differentiate PTSD from anxiety disorders. Moreover, increased frontal absolute gamma and posterior delta powers might pose as novel markers of PTSD, which may reflect its distinct symptomatology.

• New Physics: Sae Mulli
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• v.68 no.11
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• pp.1249-1261
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• 2018

The quantitative representation for the magnetic force of a cylindrical permanent magnet acting on a ferromagnetic cylindrical object was derived on the basis of magnetization theories, and the Gilbert and Ampere models of magnetism. The magnetic force derived in this study is directly proportional to the remanent magnetization magnetic field, the cross-sectional area of the permanent magnet, the saturation magnetic field, and the cross-sectional area of the ferromagnetic object and is inversely proportional to the square of the quantity related to the distance between the permanent magnet and the ferromagnetic object. The magnetic forces of an AlNiCoV cylindrical permanent magnet and a Ferrite cylindrical permanent magnet, both with a radius of 0.4 cm and a length of 7 cm, acting on ferromagnetic objects at distances farther than the radius were calculated to be less than 3.6711 N and 0.1857 N, respectively.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.59-68
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• 2021

This study was performed to identify the effect of synovium graft on conjunctiva in rabbits after dry eye induction. Six New Zealand White rabbits were used as dry eye models. Both eyes were divided to two groups as control and synovium graft group. The synovium graft was performed in fourth week after dry eye modeling. Quantitative change of tears through Schirmer tear test (STT), qualitative change of tear film through tear film break up time (TFBUT), and damage of cornea through fluorescein staining were observed for 10 weeks at intervals of two weeks. Histological examination was performed to evaluate cornea and conjunctiva at tenth week. In both groups, STT and TFBUT were significantly decreased in 4 weeks after modeling compared to 0 weeks (p < 0.05) . After synovium graft, there were increases in STT value at 4 weeks and TFBUT at 4 and 6 weeks in graft group (p < 0.05). Corneal fluorescein staining showed no significant difference between the two groups. In histopathological examination, grafted synovium was detected as round to ovoid ingression folds, well attached to grafted regions with 0.11 ± 0.04 mm² (range, 0.05-0.16 mm²). These results indicated that the synovium graft on the conjunctiva had an effect on the qualitative and quantitative improvement of the tear film even though there was no histological change.

• Mass Spectrometry Letters
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• v.13 no.1
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• pp.11-19
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• 2022

Although translational research is referred to clinical chemistry measures, correct weighting factors for linear and quadratic calibration curves with least-squares regression algorithm have not been carefully considered in bioanalytical assays yet. The objective of this study was to identify steroidogenic roles in preeclampsia and verify accuracy of quantitative results by comparing two different linear regression models with weighting factor of 1 and 1/x². A liquid chromatography-mass spectrometry (LC-MS)-based adrenal steroid assay was conducted to reveal metabolic signatures of preeclampsia in both serum and placenta samples obtained 15 preeclamptic patients and 17 age-matched control pregnant women (33.9 ± 4.2 vs. 32.8 ± 5.6 yr, respectively) at 34~36 gestational weeks. Percent biases in the unweighted model (w_i = 1) were inversely proportional to concentrations (-739.4 ~ 852.9%) while those of weighted regression (w_i = 1/x²) were < 18% for all variables. The optimized LC-MS combined with the weighted linear regression resulted in significantly increased maternal serum levels of pregnenolone, 21-deoxycortisol, and tetrahydrocortisone (P < 0.05 for all) in preeclampsia. Serum metabolic ratio of (tetrahydrocortisol + allo-tetrahydrocortisol) / tetrahydrocortisone indicating 11β-hydroxysteroid dehydrogenase type 2 was decreased (P < 0.005) in patients. In placenta, local concentrations of androstenedione were changed while its metabolic ratio to 17α-hydroxyprogesterone responsible for 17,20-lyase activity was significantly decreased in patients (P = 0.002). The current bioanalytical LC-MS assay with corrected weighting factor of 1/x² may provide reliable and accurate quantitative outcomes, suggesting altered steroidogenesis in preeclampsia patients at late gestational weeks in the third trimester.

• Journal of Environmental Science International
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• v.32 no.6
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• pp.429-440
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• 2023

Quantitative habitat model is established with species occurrence and spatial abundance data, which were usually acquired by professional field ecologists and citizen scientists. The importance of citizen science data is increasing, but the quality of these data needs to be evaluated. This study aims to identify and compare both expert-based data and citizen science data based on the performance power of quantitative models derived from both data sets. A Maximum Entropy (MaxENT) model was developed using eight environmental variables, including climate, topography, landcover and distance to forest edge. The AUC values derived from the MaxENT model were 0.842 and 0.809, respectively, indicating a high level of explanatory power. All environmental variables has similar values for both data sets, except for the distance to forest edge and rice paddy, which was relatively higher for expert-based survey data than that of the citizen science data as the distances increased. This result suggests that habitat model derived from expert-based survey data shows more ecological niche including wider ranges from forest edges and isolated habitat patches of rice paddy. This is presumably because citizen scientists focuses on direct observation methods, whereas professional field surveys investigate a wider variety of methods.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.15-31
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• 2023

In this study, we propose a novel approach to analyze big data related to patents in the field of smart factories, utilizing the Latent Dirichlet Allocation (LDA) topic modeling method and the generative artificial intelligence technology, ChatGPT. Our method includes extracting valuable insights from a large data-set of associated patents using LDA to identify latent topics and their corresponding patent documents. Additionally, we validate the suitability of the topics generated using generative AI technology and review the results with domain experts. We also employ the powerful big data analysis tool, KNIME, to preprocess and visualize the patent data, facilitating a better understanding of the global patent landscape and enabling a comparative analysis with the domestic patent environment. In order to explore quantitative and qualitative comparative advantages at this juncture, we have selected six indicators for conducting a quantitative analysis. Consequently, our approach allows us to explore the distinctive characteristics and investment directions of individual countries in the context of research and development and commercialization, based on a global-scale patent analysis in the field of smart factories. We anticipate that our findings, based on the analysis of global patent data in the field of smart factories, will serve as vital guidance for determining individual countries' directions in research and development investment. Furthermore, we propose a novel utilization of GhatGPT as a tool for validating the suitability of selected topics for policy makers who must choose topics across various scientific and technological domains.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.85-99
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• 2024

As the proliferation of hydrogen electric vehicles accelerates, there is observed diversification in hydrogen refueling station models. This diversification raises safety concerns for different types of stations. This study conducted a quantitative risk assessment of a multi-vehicle hydrogen station, capable of simultaneously refueling cars, buses, and trucks. Utilizing Gexcon's Effects&Riskcurves Software, scenarios of fire and explosion due to hydrogen leaks were assessed. The study calculated the impact distances from radiative heat and explosion overpressure, and measured risks to nearby buildings and populations. The largest impact distance was from fires and explosions at dispensers and high-pressure storage units. High-pressure storage contributes most significantly to personal and societal risk. The study suggests that conservative safety distances and proper protective measures for these facilities can minimize human and material damage in the event of a hydrogen leak.