• Korean Journal of Remote Sensing
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• v.18 no.6
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• pp.369-376
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• 2002

This paper presents a method to enhance the performance of supervised classification by separating the spectral signature of the training data sets for each class. Using clustering technique, a training data set is divided into several subsets which show a pattern of the normal distribution with small value of spectral variances. Then a supervised classification is applied with the divided training data set as training data for the temporary subclasses of the original class. The proposed method is applied to a Landsat TM image of Busan area for the applicability test. The result shows that the proposed method produces better classified results than the conventional statistical classification methods. It is expected that the proposed method will reduce the effort and expense for selecting the training data set for each class in an area which has spectrally homogeneous signature.

• Ocean Systems Engineering
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• v.5 no.3
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• pp.139-160
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• 2015

The global performance of the 5MW OC4 semisubmersible floating wind turbine in random waves was numerically simulated by using the turbine-floater-mooring fully coupled and time-domain dynamic analysis program FAST-CHARM3D. There have been many papers regarding floating offshore wind turbines but the effects of second-order wave-body interactions on their global performance have rarely been studied. The second-order wave forces are actually small compared to the first-order wave forces, but its effect cannot be ignored when the natural frequencies of a floating system are outside the wave-frequency range. In the case of semi-submersible platform, second-order difference-frequency wave-diffraction forces and moments become important since surge/sway and pitch/roll natural frequencies are lower than those of typical incident waves. The computational effort related to the full second-order diffraction calculation is typically very heavy, so in many cases, the simplified approach called Newman's approximation or first-order-wave-force-only are used. However, it needs to be justified against more complete solutions with full QTF (quadratic transfer function), which is a main subject of the present study. The numerically simulated results for the 5MW OC4 semisubmersible floating wind turbine by FAST-CHARM3D are also extensively compared with the DeepCWind model test results by Technip/NREL/UMaine. The predicted motions and mooring tensions for two white-noise input-wave spectra agree well against the measure values. In this paper, the numerical static-offset and free-decay tests are also conducted to verify the system stiffness, damping, and natural frequencies against the experimental results. They also agree well to verify that the dynamic system modeling is correct to the details. The performance of the simplified approaches instead of using the full QTF are also tested.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.19-30
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• 1990

This note describes an application of Hamiton's principle to nonlinear free-surface flow problems. Two functionals are constructed based on classical Hamilton's principle with a modification due to the presence of a free surface. As an effort towards the development of an efficient numerical scheme for our problem, we present the following three test results: i) The bounding principles of the eigenvalues for the linear dispersion relation. ii) By assuming steady solitary waves, an approximate relation between the amplitudes and the speeds of solitary waves are derived from the two functionals constructed. Their numerical results are compared with those of Longuet-Higgins & Fenton(1974). iii) The shapes and charicteristics of solitary waves are computed from two sets of functionals by varying the number of total finite elements in the fluid domain.

• The Journal of Korean Society for School & Community Health Education
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• v.15 no.3
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• pp.43-54
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• 2014

Objectives: The purpose of this study was to find out the relation factors of weight control behaviors, mental health status and body image perception in adolescents and to use basis data of health promotion for adolescents. Methods: This study used data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2, 2011). The subjects were 653 between 12-19 age. Data analysis was done with SPSS/WIN 19.0 using Chi-square test, and Logistic regression. Results: The result is as follows. The case of female adolescents, abnormal perception of body image was significantly higher on weight reduction effort and normal weight, low weight in BMI. The case of male adolescents, abnormal perception of body image was higher on normal weight in BMI. Conclusions: The adolescents tend to do unreasoning weight loss behavior without properly perception for their body image. Therefore, we suggest that adolescents be provided social support for positive body image and be developed perception program with the importance of inner values.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.8
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• pp.569-576
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• 2019

The purpose of this study aimed to examine the effects of job stress on the turnover intention through mediation of vacational consciousness and to reduce turnover intention of long-term care workers based on the results. We used 447 long-term care workers working in Seoul and Gyeonggi area. For the research purpose, the mediation effect was verified after the technical analysis and verifying multicollinearity using on SPSS and sobel-test. The results of this study are as follows: First, the lower the age of care worker and the higher the monthly household income, the higher the turnover intention. Second, the higher the perceived job stress, the higher the turnover intention. Third, the higher the job consciousness of the long-term care workers, the lower the turnover intention. Fourth, job stress of long-term care workers showed statistically significant effect on turnover intention by partial mediation of job consciousness. Based on the above results, I suggested the clinical and policy practice to prevent the separation of long-term care workers and improve the quality of care service for the elderly.

• Journal of Biosystems Engineering
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• v.43 no.4
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• pp.273-284
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• 2018

Purpose: Conventional headland turning typically requires repeated forward and backward movements to move the farming equipment to the next row. This research focuses on developing an upland agricultural robot with an optimized headland turning mechanism that enables a $180^{\circ}$ turning positioning to the next row in one steering motion designed for a two-wheel steering, four-wheel drive agricultural robot named the HADA-bot. The proposed steering mechanism allows for faster turnings at each headland compared to those of the conventional steering system. Methods: The HADA-bot was designed with 1.7-m wide wheel tracks to travel along the furrows of a garlic bed, and a look-ahead path following algorithm was applied using a real-time kinematic global positioning system signal. Pivot turning tests focused primarily on accuracy regarding the turning radius for the next path matching, saving headland turning time, area, and effort. Results: Several test cases were performed by evaluating right and left turns on two different surfaces: concrete and soil, at three speeds: 1, 2, and 3 km/h. From the left and right side pivot turning results, the percentage of lateral deviation is within the acceptable range of 10% even on the soil surface. This U-turn scheme reduces 67% and 54% of the headland turning time, and 36% and 32% of the required headland area compared to a 50 hp tractor (ISEKI, TA5240, Ehime, Japan) and a riding-type cultivator (CFM-1200, Asia Technology, Deagu, Rep. Korea), respectively. Conclusion: The pivot turning trajectory on both soil and concrete surfaces achieved similar results within the typical operating speed range. Overall, these results prove that the pivot turning mechanism is suitable for improving conventional headland turning by reducing both turning radius and turning time.

• Steel and Composite Structures
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• v.32 no.6
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• pp.807-819
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• 2019

In recent earthquakes, the failure of ceiling systems has been one of the most widely reported damage and the major cause of functionality interruption in some buildings. In an effort to mitigate this damage, some scholars have studied a series of ceiling systems including plaster ceilings and mineral wool ceilings. But few studies have involved the backdrop metal ceiling used in some important constructions with higher rigidity and frequency such as the main control area of nuclear power plants. Therefore, in order to evaluate its seismic performance, a full-scale backdrop metal ceiling system, including steel runners and metal panels, was designed, fabricated and installed in a steel frame in this study. And the backdrop metal ceiling system with two perimeter attachments variants was tested: (i) the ends of the runners were connected with the angle steel to form an effective lateral constraint around the backdrop metal ceiling, (ii) the perimeter attachments of the main runner were retained, but the perimeter attachments of the cross runner were removed. In the experiments, different damage of the backdrop metal ceiling system was observed in detail under various earthquakes. Results showed that the backdrop metal ceiling had good integrity and excellent seismic performance. And the perimeter attachments of the cross runner had an adverse effect on the seismic performance of the backdrop metal ceiling under earthquakes. Meanwhile, a series of seismic construction measures and several suggestions that need to be paid attention were proposed in the text so that the backdrop metal ceiling can be better applied in the main control area of nuclear power plants and other important engineering projects.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.99-108
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• 2019

This study aims to explore key factors which influence user's decision-making on the adoption of e-learning. We integrated UTAUT and Information Success Models to test that four independent factors affect student satisfaction to use e-learning in Rwanda's higher education. Data was collected by surveying students of University of Rwanda and Protestant Institute of Social Sciences (n=206). The analysis results showed that performance expectancy, facilitating conditions and effort expectancy except for social influence have a significant effect on students' satisfaction. This can help university administrators understand the factors that influence students' adoption of e-learning and incorporate these results into Rwanda's e-learning design and implementation. In final, Rwanda's government can contribute to establishing the e-learning policy and allocating its relevant resources centered on student needs.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.186-193
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• 2021

BACKGROUND: Before generating transgenic plant using the CRISPR-Cas9 system, the efficiency test of sgRNAs is recommended to reduce the time and effort for plant transformation and regeneration process. The efficiency of the sgRNA can be measured through the transient expression of sgRNA and Cas9 gene in tomato cotyledon; however, we found that the calculated efficiency showed a large variation. It is necessary to increase the precision of the experiment to obtain reliable sgRNA efficiency data from transient expression. METHODS AND RESULTS: The cotyledon of 11^th, 15^th, 19^th, and 23^rd-day-old tomato (Solanum lycopersicum cv. Micro-Tom) were used for expressing CRISPR-Cas9 transiently. The agrobacterium harboring sgRNA for targeting ALS2 gene of tomato was injected through the stomata of leaf adaxial side and the genomic DNA was extracted in 5 days after injection. The target gene edition was identified by amplifying DNA fragment of target region and analyzing with Illumina sequencing method. The target gene editing efficiency was calculated by counting base deletion and insertion events from total target sequence read. CONCLUSION: The CRISPR-Cas9 editing efficiency varied with tomato cotyledon age. The highest efficiency was observed at the 19-day-old cotyledons. Both the median and mean were the highest at this stage and the sample variability was also minimized. We found that the transgene of CRISPR-Cas9 system was strongly correlated with plant leaf development and suggested the optimum cotyledon leaf age for Agrobacterium-mediated transfection in tomato.

• Asia-Pacific Journal of Business
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• v.12 no.1
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• pp.41-56
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• 2021

Purpose - This empirical study examined the influence of post-communist countries sociol-political factor of freedom of expression preconditioning, and trust in agency, mediating performance expectancy of social media users representing the citizens' behavioural intention to utilize social media in a post-communist country, the case of Mongolia. Design/methodology/approach - This research collected 403 valid survey data from citizens those who use social media in Mongolia. The study used Partial Least Squire (PLS) analysis with the research conceptual model founded on the UTAUT model. Findings - The study shown that citizens in post-communist, they strongly willing freedom of expression, which driving as a positive precondition factor, and this has an indirect positive influence, and trust in agency mediates to enhance performance expectancy. Social influence, and effort expectancy factors have direct positive influence on the intention to use of social media systems in the public sector domain of Mongolia. Research implications or Originality - This research proposed a new model to test citizens' intention to use social media as a communication tool to engage with public organizations in the pre-adoption stage of post-communist countries. Theoretically, this research builds up to the unique theoretical contribution with social media by examining a new social media-based third-party intercommunication medium, incorporating intent to utilize for citizens with government in post-communist countries. Practically, this article lays out the directions to aid social media usage for government sector with concerning citizens intentions in the post-communist situation.