• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.43-52
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• 2019

As the application area of lithium secondary batteries becomes wider, performance characterization becomes difficult as well as diverse. To address this issue, battery manufacturers have to evaluate many batteries for a longer period, recruit many researchers and continuously introduce expensive equipment. Simulation techniques based on battery modeling are being introduced to solve such difficulties. Various lithium secondary battery modeling techniques have been reported so far and optimal techniques have been selected and utilized according to their purpose. In this review, the electrochemical modeling based on the Newman model is described in detail. Particularly, we will explain the physical meaning of each equation included in the model; the Butler-Volmer equation, which represents the rate of electrode reaction, the material and charge balance equations for each phase (solid and liquid), and the energy balance. Moreover, simple modeling processes and results based on COMSOL Multiphysics 5.3a will be provided and discussed.

• Journal of the Korean association of regional geographers
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• v.19 no.1
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• pp.45-59
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• 2013

This paper was to examine the spatial characteristics on the mobile industry's value chain based on the structure of value chain, the process of development, and the industrial linkages of mobile industry in Daegu-Gyeongbuk region. The mobile industry's value chain in Daegu-Gyeongbuk region consists of the infrastructure, mobile device, platform & embedded SW, and mobile contents sector. Among these sectors, the leading value chain sector in mobile governance is the mobile device sectors, especially the finished products sector. These sectors have developed by policies as well as networks with large enterprises such as Samsung and LG, and it forms a hub-and-spoke cluster. The infrastructure and mobile device sector are located in Gumi, Gyeongbuk, the embedded SW and mobile contents sectors are located in Daegu, which means decentralized agglomeration. The sectors of infrastructure and mobile device form the strong forward-backward linkages with firms in Daegu-Gyeongbuk region. For the embedded SW sector, the forward-backward linkages are active with firms located in Seoul metropolitan area. For mobile contents sector, the backward linkages are formed with firms in Daegu and the forward linkages are formed with firms in Seoul metropolitan area.

• Journal of Biomedical Engineering Research
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• v.40 no.3
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• pp.105-115
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• 2019

Brain tumor surgery may be difficult, but it is also incredibly important. The technological improvements for traditional brain tumor surgeries have always been a focus to improve the precision of surgery and release the potential of the technology in this important area of the body. The need for precision during brain tumor surgery has led to an increase in Robotic-assisted surgeries (RAS). One of the challenges to the widespread acceptance of RAS in the neurosurgery is to recognize invisible tumor accurately. Therefore, it is important to detect brain tumor size and location because surgeon tries to remove as much tumor as possible. In this paper, we proposed brain tumor detection procedures for MRI (Magnetic Resonance Imaging) system. A method of automatic brain tumor detection is needed to accurately target the location of the lesion during brain tumor surgery and to report the location and size of the lesion. In the qualitative assessment, the proposed method showed better results than those obtained with other brain tumor detection methods. Comparisons among all assessment criteria indicated that the proposed method was significantly superior to the threshold method with respect to all assessment criteria. The proposed method was effective for detecting brain tumor.

• Journal of the Korean Solar Energy Society
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• v.32 no.spc3
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• pp.275-281
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• 2012

Proton Exchange Membrane Fuel Cells (PEMFC) are the most appropriate for energy source of small robot applications. PEMFC has superior in power density and thermodynamic efficiency as compared with the Direct Methaol Fuel Cell (DMFC). Furthermore, PEMFC has lighter weight and smaller size than DMFC which are very important factors as small robot power system. The most significant factor of mobile robots is weight which relates closely with energy consumption and robot operation. This research tried to find optimum specifications in terms of type, number of cell, active area, cooling method, weight, and size. In order to find optimum 500W PEMFC, six options are designed in this paper and studied to reduce total stack weight by applying new materials and design innovations. However, still remaining problems are thermal management, robot space for energy sources, and soon. For a thermal management, design options need to analysis of Computational Fluid Dynamics (CFD) for determining which option has the improved performance and durability.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.211-216
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• 2012

Proton Exchange Membrane Fuel Cells (PEMFC) are the most appropriate for energy source of small robot applications. PEMFC has superior in power density and thermodynamic efficiency as compared with the Direct Methaol Fuel Cell (DMFC). Furthermore, PEMFC has lighter weight and smaller size than DMFC which are very important factors as small robot power system. The most significant factor of mobile robots is weight which relates closely with energy consumption and robot operation. This research tried to find optimum specifications in terms of type, number of cell, active area, cooling method, weight, and size. In order to find optimum 500W PEMFC, six options are designed in this paper and studied to reduce total stack weight by applying new materials and design innovations. However, still remaining problems are thermal management, robot space for energy sources, and so on. For a thermal management, design options need to analysis of Computational Fluid Dynamics (CFD) for determining which option has the improved performance and durability.

• Journal of Forest and Environmental Science
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• v.35 no.1
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• pp.61-68
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• 2019

The purpose of this study is to evaluate the natural habitat of Hotaria unmunsana Doi, which was first discovered at Mt. Unmun also represents a landscape indicator species for Daegu and Gyeongbuk provinces, and Luciola lateralis Motschulsky, which is the object of experiential activation at festivals in some cities in the region. The spatial range of this study is limited by Daegu City and Gyeongbuk province, and is used to predict the preference of firefly for altitude, slope, direction, shaded relief, riparian buffer zone, river environment, and farmland to analyze the area that best matches the habitat of fireflies. As a result, fireflies are highly influenced by altitude and there may be no large-scale habitats in some areas through the Nakdong and the Baekdu mountain ranges, which occur at high altitude. In most of the cities, we found major habitats around the streams and wetlands. By region, the sites were widely distributed around the cities focused on Nakdong River, and many habitats emerged around the Nakdong River tributary and gentle slopes. In order to preserve and spread the habitat of fireflies, the physical environment as well as their relationship with food chains and symbiotic organisms should be established, and excessive use of pesticides and herbicides in agricultural areas should be avoided.

• Journal of Yeungnam Medical Science
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• v.39 no.1
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• pp.46-52
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• 2022

Background: The coronavirus disease 2019 (COVID-19) outbreak in the Daegu-Gyeongbuk area in 2020 has caused difficulties in the daily life and hospital care of children with type 1 diabetes mellitus (T1DM). We detected an increase in blood sugar levels in these children and the number of patients hospitalized with more severe diabetic ketoacidosis (DKA) compared to those before COVID-19. Methods: This single-center study was conducted at Kyungpook National University Children's Hospital. The following patient groups were included; 45 returning patients diagnosed with T1DM and undergoing insulin treatment for more than 2 years and 20 patients newly diagnosed with T1DM before and after COVID-19 were selected by age matching. Returning patients before and after the outbreak were selected, and changes in hemoglobin A1c (HbA1c) levels were retrospectively reviewed. The HbA1c levels and severity of symptoms in newly diagnosed patients during hospitalization were examined. Results: HbA1c levels in returning patients with T1DM were significantly increased after COVID-19 (before, 7.70%±1.38% vs. after, 8.30%±2.05%; p=0.012). There were 10 and 10 newly diagnosed patients before and after COVID-19, respectively. The proportion of patients with drowsiness and dyspnea at the time of admission was higher after COVID-19 than before (before, 2 of 10 vs. after, 4 of 10). The HbA1c levels were higher in newly diagnosed patients hospitalized after COVID-19 than before (before, 11.15% vs. after, 13.60%; p=0.036). Conclusion: Due to COVID-19 in the Daegu-Gyeongbuk area, there was an increase in blood glucose levels in children with T1DM and in the incidence of severe DKA in newly diagnosed diabetes mellitus patients.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1473-1478
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• 2018

In this study, we have developed a simple and cost-effective method to prevent edge bead formation by covering the edge of a chip-level substrate with heat-resistant tape during patterning using SU-8. Edge beads are a fundamental problem in photoresists and are particularly notable in high-viscosity fluids and thick coatings. Edge beads can give rise to an air gap between the substrate and the patterning mask during UV exposure, which results in non-uniform patterns. Furthermore, the sample may break since the edge bead is in contact with the mask. In particular, the SU-8 coating thickness of the chip-level substrates used in MEMS or BioMEMS may not be properly controlled because of the presence of edge beads. The proposed method to solve the edge bead problem can be easily and economically utilized without the need for a special device or chemicals. This method is simple and prevents edge bead formation on the sample substrate. Despite the small loss in the taping area, the uniformity of the SU-8 coating is improved from 50.9% to 5.6%.

• Proceedings of the KSR Conference
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• 2008.06b
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• pp.27-41
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• 2008

Construction of metro transportation infra is a large-scale project requiring tremendous financial resources. This study suggests operation method to use for rapid transit line existing infra such as Gyeongbu line and spare line capacity following second phase KTX construction. Reviewing various constraints of metro rapid transit operation, we found that the conditions for metro rapid transit operation are already satisfied in Daegu area, just like the case of Gyeongbu line in Seoul Metro area. Also, the evaluation of the economic feasibility of metro rapid transit operation in Daegu area shows that B/C is about 2.4, which implies that there is sufficient economic feasibility. According to the result of sensitivity analysis, the project is economically feasible unless the passenger demand decreases 15% and construction costs increases more than 70%. B/C is evaluated large because the utilization of already exiting infra lowers the initial cost. As one of mass transportation system of large capacity, metro rapid transit can generate significant spillover effect: It will strengthen competitiveness of metro area by connecting cities within the area and by extending one-day life zone of the area, to say nothing of the benefit of improving traffic condition. The construction of metro rapid transit network is necessary for the mass transportation system of Yeongnam area as well as Daegu area, and it may work as a starting point for uniting Daegu and Gyeongbuk and strengthening regional competitiveness.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.434-440
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• 2010

This study was conducted among university students living in the Daegu-Gyeongbuk region to determine the perception, Preference, and improved consciousness of Gyeongbuk local foods classified by the Yugyo, Silla, Ocean, and Gaya cultures. In the Andong area, subjects demonstrated outstanding, high rates of perception of and preference for local foods. The perception of and preference for foods from the Yugyo and Silla cultures were relatively high compared to those of others. The degree of perception of Gwamegi foods was high, but the degree of preference was rather low. It is believed that establishing new counterplans is necessary to obtain higincrease preference for foods from the Ocean culture. Sigeumjang foods of the Ocean culture showed alow degree of both perception and preference. The analysis showed that there was a discrepancy between the perception of and preference for foods in the Gaya culture. To improve the relationship between awareness of and preference for foods in the same culture we determined that menu strategy, development strategy and sales strategy were important factors. The results of the survey investigating the correlation between improved awareness of and perception of foods showed menu strategy and development strategy had meaningful effects. According to the survey, the factors that influenced choices of foods local to Yugyo were classified into categores-: menu strategy, development strategy, product strategy, and sales strategy.