• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.39-49
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• 2011

Recently PBD method, one of acceleration of consolidation methods is used in the soft ground to shorten consolidation time for fast settlement during construction. It is economical and easy to work. Discharge capacity of PBD is sensitive in proportion to thickness of soft ground layer, and drainage of PBD declines due to disturbance effect in surrounding ground by mandrel used for vertical drainage setting and setting machines and type. Also, deviation of discharge capacity is large according to ground condition, construction condition and soil properties. In addition, when embankment loading is not conducted instantly after PBD setting due to rain or lack of embankment material supply, it causes leaving period problems. But cause and analysis of those problems for discharge capacity is lack. So, in this test, ground improvement and discharge capacity is investigated by implementing composite discharge capacity test for analysis of an effect factor of PBD discharge capacity with leaving period. After fixing the vertical drain on a cylindrical cylinder, put churned sample into the cylinder. Then leave 0day, 30day, 60day and 90day. And then, load following the loading step of 30, 70 and 120kPa using a pressure device. As a result, the longer leaving period, discharge capacity is reduced. It is caused by a decrease of discharge area caused by creep transformation moisture absorption of PBD filter after long leaving period.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.6
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• pp.115-133
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• 2020

With the rapid changes in the industry paradigm including the 4th industrial revolution, the survival and sustainable growth of SMEs and venture capital companies are facing a more difficult environment. The organizational capabilities help these companies to overcome the difficulties, such as absorption capacity, innovation capacity, adaptation capacity. It require many interconnected functions and capabilities to increase company performance. This study is based on the research about market adaptation capacity (agility, flexibility)'s mediating effect between organizational capacity(absorption capacity, innovation capacity, adaptation capacity) and corporate performance(financial, non-financial performance). According to the results of empirical analysis, First, Absorption capacity have a significant effect on agility. Second, Innovation capacity have a significant effect on flexibility. Third, Innovation capability have a significant effect on corporate performance. Fourth, Flexibility have a significant effect on corporate performance. Fifth, The mediating effect of flexibility between organizational capability and corporate performance was verified. Finally this paper also propose some suggestions on how to increase corporate performance for SMEs.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.135-146
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• 2020

In the strawberry cultivation areas and domestic farms, two-spotted spider mites are the most serious pests. It decreases the product yield due to the direct feeding of chlorophyll by the mites resulting in reduced photosynthetic ability of host plant. In this study, a simplified acaricidal effect evaluation system (SAEES) was employed to choose the effective acaricidal products among 10 items based on leaf-dipping bioassay methods. SAEES had the advantage of being able to screen four commercial products with three replications at the same time in the recommended concentration. The susceptible strains (SL_YS) showed a high mortality rate of about 90-100%, whereas the mortality of local strains was differed by each acaricides. It suggests that the acaricide responses of field populations might differ due to spray frequencies and acaricide product. An efficacy index (0.8-1.0) was determined based on the mortality of susceptible strain, which would allow the most effective commercial products to be selected by the range of this index. In summary, SAEES will enable the selection of effective commercial products and contribute to increasing control against T. urticae in strawberries.

• Journal of the Korea Computer Graphics Society
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• v.28 no.5
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• pp.1-11
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• 2022

Game engines have the advantage of enabling efficient content production, such as reducing development time, with minimal visual quality guarantees and support for multi-platforms. Recently, game engines have provided various functions that can easily, quickly, and effectively produce immersive content using virtual reality (VR) HMD. Therefore, this study conducts a comparative study on the development environment in VR content production using Oculus Quest 2 HMD, focusing on Unity and Unreal game engines, which are widely used in the content production industry, including games. First, we compare the basic setup process of building a development environment using Oculus Quest 2 HMD and a dedicated controller based on a VR template project that includes the minimum functions and settings provided by each engine. Next, we present a simple experience environment that can interact in a virtual environment and compare the development environment to use a dedicated controller and the process of building a development environment that directly utilizes hands through the hand tracking function provided by Oculus Quest 2. Through this process, we will understand the basic process of building a VR development environment, and at the same time, we will check the characteristics and differences of the engine and use it as a research that can be applied to various immersive content production.

• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.1
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• pp.15-26
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• 2022

Purpose Recently, in the process of examining the self-disposal of radioactive waste by the Korea Institute of Nuclear Safety, it is difficult to reach the final approval process for self-disposal. In connection with this, we intend to increase the processing efficiency of self-disposal and strengthen safety by analyzing cases of recent supplementary matters. Materials and Methods From 2018 to 2021, we compare and review a supplementary requests that preparing the procedures and plans for the self-disposal of radioactive waste by 20 institutions. In this regard, based on the provisions of the Atomic Energy Safety Act, we derive a detailed proposals for the self-disposal of radioactive waste by arranging the review processing period calculation and supplementary requests that occurred during the review process. Results The representative supplementary requests of the Korea Institute of Nuclear Safety are the calculation of the storage period by type and nuclide of radioactive waste, the contents of the packaging container, the RASIS reporting method, the planned storage method for self-disposal, confirmation of the final disposal company, and the storage period of the waste filter Calculation, radioactive labeling, etc. And it is emphasized as important. Conclusion The expected effects of the guidelines reflecting the latest supplements include reduction of the time required for document preparation and increase of work processing efficiency, improvement of storage efficiency in the radioactive waste storage room, and economic cost reduction. If the radioactive waste self-disposal guideline presented in this study is applied to the field, it is thought that it will be helpful in improving the work efficiency of those who are experiencing difficulties.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.143-151
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• 2010

Fingerprint classification is a step to increase the efficiency of an 1:N fingerprint recognition system and plays a role to reduce the matching time of fingerprint and to increase accuracy of recognition. It is difficult to classify fingerprints, because the ridge pattern of each fingerprint class has an overlapping characteristic with more than one class, fingerprint images may include a lot of noise and an input condition is an exceptional case. In this paper, we propose a novel approach to design a stochastic model and to accomplish fingerprint classification using a directional characteristic of fingerprints for an effective classification of various qualities. We compute the directional value by searching a fingerprint ridge pixel by pixel and extract a directional characteristic by merging a computed directional value by fixed pixels unit. The modified Markov model of each fingerprint class is generated using Markov model which is a stochastic information extraction and a recognition method by extracted directional characteristic. The weight list of classification model of each class is decided by analyzing the state transition matrixes of the generated Markov model of each class and the optimized value which improves the performance of fingerprint classification using GA (Genetic Algorithm) is estimated. The performance of the optimized classification model by GA is superior to the model before the optimization by the experiment result of applying the fingerprint database of various qualities to the optimized model by GA. And the proposed method effectively achieved fingerprint classification to exceptional input conditions because this approach is independent of the existence and nonexistence of singular points by the result of analyzing the fingerprint database which is used to the experiments.

• Nuclear Engineering and Technology
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• v.26 no.1
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• pp.140-148
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• 1994

A qualification test was performed for the iron removal chemical cleaning of the secondary side of nuclear steam generators at the selected temperature, 1$25^{\circ}C$, higher than the standard application temperature, 93$^{\circ}C$. The field cleaning condition for a nuclear unit was tested in a bench scale test loop including a SUS 316 stainless steel autoclave with one gallon capacity as a test vessel. The kinetics of sludge dissolution, corrosion of the secondary side materials and change of solvent chemistry were monitored. Test results indicated that more thorough cleaning was accomplished in less than half of the cleaning time required at 93$^{\circ}C$. And the total corrosions of the secondary side materials were found to be less than the values at 93$^{\circ}C$. While the solvent is recirculated and heated by an external chemical cleaning equipment for the conventional 93$^{\circ}C$ process, the secondary side is heated by the lateral heat of the primary coolant without the recirculation of the cleaning solution, and the solvent is mixed by vigorous boiling induced by periodic ventilation for the high temperature process. The requirement that the reactor coolant pumps should be running during the cleaning operation is the major disadvantage of the high temperature process which also should be considered when chemical cleaning is planned for steam generators under operation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.661-667
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• 2006

In this study, an experiment of sewage sludge dewatering is carried by using electrokinetic method, and the electrokinetic dewatering efficiency of digested sludge is analyzed. Digested sludge without coagulants is selected and gravitational and pressing dewatering methods are applied in combination with electro-osmotic and electro-osmotic pulse technology. After the test of digested sludge, dewatering test of thickened sludge is carried to evaluate the electrokinetic dewatering feasibility of thickened sludge. Under the condition of constantly applied voltage, however, electrical resistance increases with decreasing of water content so that dewatering rate decreases with time. To reduce such a hindrance caused by constantly applied voltage, electro-osmotic pulse technology which is considered to reduce the difference of water content with height, is applied. For the application of electro-osmotic pulse, the dewatered flow rate and the dewatered volume became more increasing from the middle of the dewatering process than that of continuous voltage. Through the test of thickened sludge, electro-osmotic dewatering combined with gravitational and expression also showed high dewatering rate, which proved the possibility of using electrokinetic dewatering.

• Research in Plant Disease
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• v.30 no.3
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• pp.294-299
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• 2024

Polymerase chain reaction (PCR) methods, including conventional PCR (cPCR) and quantitative real-time PCR (qRT-PCR), with both plasmid- and chromosome-targeting primers, are currently the most reliable methods for detecting Erwinia amylovora due to their high sensitivity and specificity. Despite qRT-PCR's quantitative advantage, cPCR remains an attractive method to detect this bacterium in initial screenings of suspected host plants, as it is cost-effective and does not require skilled personnel in well-equipped laboratories. This study aimed to significantly improve cPCR robustness via application of bovine serum albumin (BSA) as a PCR facilitator, with a modified EaF/R primer pair, as previously reported. Experiments have shown that simple supplementation with BSA (10 mg/ml) enhances cPCR reactions using templates such as genomic DNA, bacterial cells, and infected symptomless host organs, including immature apple fruits and seedlings, with EaF/R primers. The cPCR method described in this study is simple, specific, and reliable, and can be applied in routine assays to diagnose fire blight.

• Journal of IKEEE
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• v.28 no.3
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• pp.458-464
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• 2024

This study proposes a fault-tolerant caching system to address the issue of caching content imbalance caused by the dynamic departure and participation of cache servers in a heterogeneous cache server network, and validates it in both real and virtual environments. With the increase of large-scale media content requiring various types and resolutions, the necessity of cache servers as key components to reduce response time to user requests and alleviate network load has been growing. In particular, research on heterogeneous cache server networks utilizing edge computing and low-power devices has been actively conducted recently. However, in such environments, the irregular departure and participation of cache servers can occur frequently, leading to content imbalance among the cache servers deployed in the network, which can degrade the performance of the cache server network. The fault-tolerant caching algorithm proposed in this study ensures stable service quality by maintaining balance among media contents even when cache servers depart. Experimental results confirmed that the proposed algorithm effectively maintains content distribution despite the departure of cache servers. Additionally, we built a network composed of seven heterogeneous cache servers to verify the practicality of the proposed caching system and demonstrated its performance and scalability through a large-scale cache server network in a virtual environment.