• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.31-37
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• 2018

In the surface contamination test using the end-window Geiger-Muller type counter, the wrap is used as a method for protecting the detector exposed to the outside in order to measure the beta-rays. We analyze the effect of this method on the measurement rate and the correction factor, and wanted to make it clear to radiation workers that excessive use of the wrap can affect the measured value of the beta-rays. The experimental method was to compare and analyze the change of the beta-rays measurement counting rate and the calibration factor according to the wrap thickness using the beta-rays with different energy of 3 KBq, 1.5 KBq and 0.3 KBq. The subjects of this study were the end-window Geiger-Muller type counter which were held at the calibration center certified by Korea Laboratory Accreditation Scheme (KOLAS) in March 2012, Cl-36 (Chlorine) and Sr-90 (Strontium) were used as the source of beta radiation. The measurement counting rate decreased with increasing wrap thickness, and the calibration factor increased with increasing wrap thickness. Since the changes of the measurement counting rate and the calibration factors can reduce the accuracy of the instrument readings, but also have a significant impact on detector contamination and damage, so there is a need to find out what thickness of wrap is most effective. If we using a wraps with thickness that show a low rate of change of the measurement counting rate and the calibration factor, it will protect the detector and minimize the effect on the measured value of the beta-rays.

• Journal of Life Science
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• v.26 no.12
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• pp.1470-1476
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• 2016

The viral hemorrhagic septicemia virus (VHSV), which belongs to the Novirhabdovirus genus of the Rhabdoviridae family, is a viral pathogen that causes severe losses in the olive flounder farming industry. Among six encoding VHSV proteins, the non-virion (NV) protein has been shown to have an impact on virulence. In our previous studies, transcriptomics microarray analysis by using VHSV-infected olive flounder showed that VHSV infection significantly down-regulated the mRNA expression of glycolytic enzymes. In addition, VHSV NV protein variants decreased the intracellular ATP level. Based on these results, we have tried to examine the effect of VHSV NV protein on glycolytic enzyme glucokinase expression, which phosphorylates glucose to glucose 6-phosphate. Our results indicated that the NV protein significantly decreased the mRNA expression of glucokinase in olive flounder HINAE cells. Furthermore, the NV protein played a negative role in the promoter activation of glucokinase. Furthermore, glucose uptake was effectively inhibited by VHSV infection and NV protein expression in olive flounder HINAE cells. These results suggest that the VHSV NV protein negatively regulates glycolytic enzyme expression by a transcription level and eventually leads to gradual morbidity of olive flounder through cellular energy deprivation. The present results may be useful for the prevention and diagnosis of VHSV infection in olive flounder.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.196-201
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• 2015

This paper presents the impact of partial shading on $CuIn_xGa_{(1-x)}Se_2(CIGS)$ photovoltaic(PV) modules with bypass diodes. When the CIGS PV modules were partially shaded, the modules were under conditions of partial reverse bias. We investigated the characterization of the bypass diode and solar cell properties of the CIGS PV modules when these was partially shaded, comparing the results with those for a crystalline silicon module. In crystalline silicon modules, the bypass diode was operated at a partial shade modules of 1.67 % shading. This protected the crystalline silicon module from hot spot damage. In CIGS thin film modules, on the other hand, the bypass diode was not operated before 20 % shading. This caused damage because of hotspots, which occurred as wormlike defects in the CIGS thin film module. Moreover, the bypass diode adapted to the CIGS thin film module was operated fully at 60% shading, while the CIGS thin film module was not operated under these conditions. It is known that the bypass diode adapted to the CIGS thin film module operated more slowly than that of the crystalline silicon module; this bypass diode also failed to protect the module from damage. This was because of the reverse saturation current of the CIGS thin film, $1.99{\times}10^{-5}A/cm^2$, which was higher than that of crystalline silicon, $8.11{\times}10^{-7}A/cm^2$.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.587-614
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• 2018

The Korean government is aiming to strengthen industrial and national competitiveness through the promotion of cooperation between universities, public research institutes and industry and vitalization of technology transfer. In 2013 and 2014, the Ministry of Trade, Industry and Energy and Ministry of Science, ICT and Future Planning have announced policies to support SMEs by public research organizations. In addition, in 2015, the 'Korean Fraunhofer support system', which pay government subsidies according to the amounts of private R&D funds was adopted. However, there are some concern about the government's policies. There is yet disclosed how these policies affect technology transfer because industrial R&D funding has not been activated in Korea unlike German. Therefore this paper analyzes effects of relationship between universities, public research institutes and external organizations on performance of technology transfer based on the Triple Helix Model. Empirical results show that the relationship with the government has a significant impact on the resource security and the relationship with the industry has a significant effect on the diffusion of the performance. In addition, a public research institute was selected and case analysis was conducted to suggest policy implications for improving the technology transfer performance of universities and public research institutes.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.84-92
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• 2019

The deterioration of the urban heat environment due to climate change and the occurrence of heat-related diseases have emerged as one of the major social problems. This has led to more research on climate change, including heat waves, but it is mainly focused on climate factors. However, the urban heat island phenomenon accelerates the summer heat wave, and the increasing trend of heat-related patients in urban areas suggests the impact of the city's environment. Thus, this study analyzed the effects of physical and social characteristics of urban areas on heat-related patients in Seoul and Gyeonggi-do. The analysis showed that the ratio of the total area of residential, commercial and industrial facilities, the main source of heat energy locality, among the land use statuses, was not statistically significant, but the road area and the green area were found to have a positive and negative The population density and the percentage of people aged 65 or older, the percentage of people living alone and the proportion of people receiving basic living were all shown to be significant, with only the ratio of elderly living alone and the ratio of population density having negative effects. The results of the study can be used to develop urban policy alternatives related to local warming patients.

• Korean Journal of Construction Engineering and Management
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• v.18 no.5
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• pp.11-19
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• 2017

The purpose of this study is to analyze the efficiency of PV according to installation condition in the complex type buildings. For this purpose, annual performance of solar power generation in a certain area was investigated and various methods were conducted including post operation evaluation. In addition, we tried to find out influencing factors that affect the efficiency and sought to identify their relative impact of degree through the data analysis and site visits together. In the middle of this process we can draw up major considerations for the efficient photovoltaic power generation installation. In the mean while, previous studies are making something new related with method for efficiency enhancement and individual influential factors based on experimental environment rather than the empirical data site based. As a result of the study, it was confirmed that even if installed in the same area, the power generation efficiency is 1.5 times as high as the installation condition. Furthermore, statistical analyses were performed on azimuth, tilted angle and shade, which are variables affecting conversion efficiency, and it was statistically confirmed that all variables are meaningful factors that affect the conversion efficiency which is a dependent variable. The most influential factor is the azimuth, followed by the tilted angle and the shade factor. From this result, we expect to be able to provide installation guidelines for the solar power generation equipments on the rooftop zone.

• Resources Recycling
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• v.29 no.3
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• pp.11-23
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• 2020

This study aims to investigate breakage and liberation characteristics of iron ore from Shinyemi mine, Jeongseon by ball mill. Parameters of breakage functions for three grade samples of iron ore were obtained using single-sized-feed breakage test and back-calculation based on nonlinear programming. The results showed that with the increase in the grade of iron ore, the breakage rate factor decrease whereas the particle size sensitivity decreases. This results from retardation of microcrack-propagation by magnetite grain in the ore. Breakage distribution analysis showed that the breakage mechanism appear to be impact fracture dominant with the increase of grade owing to the stress distribution effect by magnetite grain. Degree of liberation (DOL) increased with the increase in grade and decrease in particle size, respectively. Using the breakage function and size-DOL relationship, a model that can predict time-dependent-DOL is established. When scale-up factors from operating condition are available, the model is expected to be capable of predicting size and DOL with time in actual mining process.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.107-116
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• 2002

Crash Cushion is a kind of safety facilities on roadside which acts the role of absorbing impact energy when vehicles are driven out of normal route such as Gore area of freeway off ramp. Criteria for severity index considering accident occurrence possibility are needed to have strong effect on installing the facilities. However, present criteria for establishing crash cushion design do not include such processes. Therefore, the paper presents two kinds of study to develop criteria for severity index. First of all, development of accident forecasting model on freeway off ramp is presented. The module is a relationship between accidents and road environment by negative binomial distribution (NB) which is called to reflect very well quality of accidents at Gore of crash cushion installed freeway Secondly, freeway exiting behavior model is developed because the human factor is the most important one. However, many literatures have shown between road environment and accidents which are more quantitative than human factor. The study supposed advanced process steps on actual freeway and analysed correlation between variables and accidents. The criteria for severity index is presented to determine whether to install or not by benefit cost analysis for each module. The standard for severity index will help to determine whether to install the crash cushion or not and to estimate severity for freeway and off ramp.

• Structural Engineering and Mechanics
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• v.76 no.6
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• pp.687-708
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• 2020

Openings in steel plate shear walls (SPSWs) are usually used for decorative designs, crossing locations of multiple utilities and/or structural objectives. However, earlier studies showed that generating an opening in an SPSW has a negative effect on the cyclic performance of the SPSW. Therefore, this study proposes tripling or doubling the steel-sheet-plate (SSP) layer and stiffening the opening of the SPSW to provide a solution to undesirable opening effects, improve the SPSW performance and provide the infill option of potential strengthening measures after the construction stage. The study aims to investigate the impact of SSP doubling with a stiffened opening on the cyclic behaviour, expand the essential data required by structural designers and quantify the SPSW performance factors. Validated numerical models were adopted to identify the influence of the chosen parameters on the cyclic capacity, energy dissipation, ductility, seismic performance factors (SPF) and stiffness of the suggested method. A finite Element (FE) analysis was performed via Abaqus/CAE software on half-scale single-story models of SPSWs exposed to cyclic loading. The key parameters included the number of SSP layers, the opening size ratios corresponding to the net width of the SSP, and the opening shape. The findings showed that the proposed assembly method found a negligible influence in the shear capacity with opening sizes of 10, 15, 20%. However, a deterioration in the wall strength was observed for openings with sizes of 25% and 30%. The circular opening is preferable compared with the square opening. Moreover, for all the models, the average value of the obtained ductility did not show substantial changes and the ultimate shear resistance was achieved after reaching a drift ratio of 4.36%. Additionally, the equivalent sectional area of the SSP in the twin and triple configuration of the SPSWs demonstrated approximately similar results. Compared with the single SSP layer, the proposed configuration of the twin SSP layer with a stiffened opening suggest to more sufficiency create SSP openings in the SPSW compared to that of other configurations. Finally, a tabular SPF quantification is exhibited for SPSWs with openings.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.483-490
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• 2022

Floating LiDAR is a system that provides a new paradigm for wind condition observation, which is essential when creating an offshore wind farm. As it can save time and money, minimize environmental impact, and even reduce backlash from local communities, it is emerging as the industry standard. However, the design and verification of a stable platform is very important, as disturbance factors caused by fluctuations of the buoy affect the reliability of observation data. In Korea, due to the nation's late entry into the technology, a number of foreign equipment manufacturers are dominating the domestic market. The west coast of Korea is a shallow sea environment with a very large tidal difference, so strong currents repeatedly appear depending on the region, and waves of strong energy that differ by season are formed. This paper conducted a study examining buoys suitable for LiDAR operation in the waters of Korea, which have such complex environmental characteristics. In this paper, we will introduce examples of optimized design and verification of ship-type buoys, which were applied first, and derive important concepts that will serve as the basis for the development of various platforms in the future.