• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.779-793
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• 1998

In this study, for the purpose of water supply planning, we propose a sophisticated multi-period mixed integer programming model that can coordinate the behavior of multi-reservoir operation, minimizing unnecessary spill. It can simulate the system with operating rules which are self- generated by the optimization engine in the algorithm. It is an optimization model in structure, but it indeed simulates the coordinating behavior of multi-reservoir operation. It minimizes the water shortfalls in demand requirements, maintaining flood reserve volume, minimizing unnecessary spill, maximizing hydropower generation release, keeping water storage levels high for efficient hydroelectric turbine operation. This optimization model is a large scale mixed integer programming problem that consists of 3.920 integer variables and 68.658 by 132.384 node-arc incidence matrix for 28 years of data. In order to handle the enormous amount of data generated by a big mathematical model, the utilization of DBMS (data base management system)seems to be inevitable. It has been tested with the Han River multi-reservoir system in Korea, which consists of 2 large multipurpose dams and 3 hydroelectric dams. We demonstrated successfully that there is a good chance of saving substantial amount of water should it be put to use in real time with a good inflow forecasting system.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.656-664
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• 2015

To produce high quality watermelon, three tetraploid watermelon breeding lines (‘SA03-1’, ‘SA06-1’ and ‘SB01-1’) were developed by treatment with different chromosome doubling reagents. To identify the optimal tetraploid inductive conditions, the three watermelon breeding lines were selected by counting the number of doubled chloroplasts in guard cells. Tetraploid induction rates differed depending on the genotypes and treatment with doubling reagents. However, the highest induction rate occurred with 1.0% colchicine (82.2%). These putative tetraploid lines were re-confirmed for ploidy using flow cytometric analysis and chromosome counting. The internode length of the tetraploid breeding lines was different when the leaf size was larger in all three tetraploid lines compared to their diploids. The fruit weight of the tetraploid fruits for ‘SA03-1’ and ‘SB01-1’ was lower than for their diploid, and the rind thickness and total sugar content (°Brix) of tetraploid SB01-1 were significantly different from those of its diploid. Tetraploid lines were sterile, yielded a lower number of seeds per fruit for ‘SA03-1’ (21), ‘SA06-1’ (62), and ‘SB01-1’ (34.7), and the seeds were larger and thicker than those of their diploids. These tetraploid breeding results will be useful for breeding new seedless watermelon cultivars.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.277-282
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• 1996

This study was carried out to understand the flowering and pollination characteristics in Bupleurum falcatum. Estimated total node numbers of primary branches were 106.6, and the total numbers of florets were theoretically 9,622 until secondary branches flower. In the sizes of floral organs according to the branch order, all of ray, pedicel, petal, pistil, stamen, ovary surface, and sepals have a tendancy to be smaller as this order: main stem> 1st branch> 2nd branch. As the branch development proceeds, the size of florets was getting smaller. Each flowering periods, especially stamen emergence, in different branch positons and in intra-branch were clearly divided. In case of florets, umbellets, and compound umbels enveloped in the gauze and paper, they showed 0% fertilization rate. However, the plants which were entirely enveloped in gauze led to the partial fertilization. Consequently, it was admitted that B. falcatum was a partly allogamous plant, fertilized in the way of entomophily. In respect of pol­linatability according to the steps of floral organs maturation, this plant was able to bear fruit after 8 days (Pistil maturation). It was at maturity stages, especially 11 through 13 days, that the maximum fer­tilization rate appeared.

• Journal of The Korean Association For Science Education
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• v.37 no.5
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• pp.879-889
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• 2017

The purpose of this study is to develop the evaluation criteria for students' research reports on online science inquiry problems that promote thinking abilities. The steps of developing the evaluation criteria are as follows; First, based on previous study results and literature review, the evaluation categories of the science inquiry contents were determined: 1) knowledge, 2) logical and analytical thinking, 3) critical thinking, 4) science process skills, 5) problem-solving, and 6) creative thinking. Second, evaluation criteria are developed according to the following steps: 1) define each category, 2) identify sub-category, 3) develop evaluation criteria for all categories that could serve as guidelines in the development of scoring rubrics, and 4) expert validation processes were performed. Finally, the usability test for these evaluation categories and criteria were done by being applied to the development of real scoring rubrics for 24 problems included in e-learning contents. Then the users' feedbacks were filed and the implications of this study were discussed.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.119-124
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• 2002

This study was carried out to investigate the effects of packing materials of frozen boar semen to improve reproductive performance efficiency in pig. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. We compared packing protocols for frozen boar semen among 5$m\ell$ maxi-straw, 5$m\ell$ cryogenic-vial, and aluminum-pack. Cryogenic-vial packing material showed similar sperm characteristics compared with maxi-straw packing material when the sperm was frozen above 15cm from liquid nitrogen and thawed at 52$^{\circ}C$ for 190 seconds. We investigated different thawing times to find out the optimal condition of freezing and thawing protocol with cryogenic-vial. Freezing above 15cm from liquid nitrogen and thawing at 52$^{\circ}C$ for 190 seconds were the optimal protocol compared with 120 and 150 seconds. However, normal acrosome rates did not show any differences among thawing times. Post-thawing results of maxi-straw in water at 52$^{\circ}C$ for 45 seconds had better total motility and curve linear velocity than those of cryogenic-vial in water 52$^{\circ}C$ for 190 seconds. However, there were no differences on straightness and normal apical ridge of sperm between maxi-straw and cryogenic vial. Non-return rate, farrowing rate and litter size of sows inseminated with frozen boar semen of commercial farms were higher in the maxi-straw than cryogenic-vial, but there were no significant differences between maxi-straw and cryogenic-vial. In conclusion, there were no significant differences between maxi-straw and cryogenic-vial and so, we may replace cryogenic-vial packing method instead of maxi-straw packing method by improvement of freezing and thawing rate.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.3
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• pp.87-99
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• 2009

We evaluated modified Soil-Plant-Atmosphere model's performance to simulate the seasonal variation of net ecosystem exchange (NEE) of carbon and examined the critical controlling mechanism on carbon exchange using the model over a deciduous forest at Gwangnung in 2006. The modified Soil-Plant-Atmosphere (mSPA) model was calibrated to capture the mean NEE during the daytime (1000-1400 LST) and used to simulate gross primary productivity (GPP). Ecosystem respiration ($R_e$) has been estimated using an empirical formula developed at this site. The simulation results indicated that the daytime mean stomatal conductance was highly correlated with daily insolation in the summer. Low stomatal conductance in high insolation occurred on the days with low temperature rather than with high vapor pressure deficit. It suggests that the forest rarely experienced water stress in the summer of 2006. The model captured the observed bimodal seasonal variation with a mid-season depression of carbon uptake. The model estimates of annual GPP, $R_e$ and NEE were $964\;gC\;m^{-2}\;yr^{-1}$, $733\;gC\;m^{-2}\;yr^{-1}$, and $-231\;gCm\;^{-2}\;yr^{-1}$, respectively. Compared to the observed annual NEE, the modeled estimates showed more carbon uptake by about $140\;gC\;m^{-2}\;yr^{-1}$. The uncertainty of the estimate of annual NEE in a complex terrain is discussed.

• Journal of Gifted/Talented Education
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• v.10 no.2
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• pp.1-23
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• 2000

The Schoolwide Enrichment Model(SEM) is a representative model for the gifted education. As the model seems to be more conceptual in nature, it is hard to respond to the different interests and changing needs of the gifted learners. Also it does not provide specific procedures and prescriptions in teaching-learning processes for the teachers. Therefore, SEM needs to be modified into a Systemic Model that is more flexible and procedural. The paper proposes an Instructional Systems Design(ISD) model for SEM. The Systemic Model for SEM consists of 5 major steps. These are as follows: Planning, Diagnosis, Prescription, Implementation, Evaluation. In Planning step, there is a six-stage procedure for initiating the implementation of the SEM. In Diagnosis step, there are two-phases in identifying students for participation in the SEM and assessing strengths, interests, and talents of the learners and recording in The Total Talent Portfolio(TTP). In Prescription step, Curriculum Compacting is administered as a systematic procedure for modifying thecurriculum for above-average ability students. In Implementation step, Enrichment Learning and Teaching is an instructional strategy designed to promote active engagement in learning for teachers and students. Whenever each step has completed, Evaluation step should be followed. These 5 steps are repetitive, cycling and interactive. That is, each one becomes input for the next step, process for itself, and output for the previous step. Each step is monitored through the process of Review and Revision step. In conclusion, the paper suggests six strengths of the Systemic Model for SEM; The Model (1) provides the specific procedure in teaching-learning process; 92) has interactive relations with each component; (3) can be revised continuously for creation of the most effective system; (4) can be implemented more flexibly; (5) can be developed as an unique system for each school; (6) facilitates communications between teachers and students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3260-3269
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• 2014

The construction industry has strong ties with other industries, and so construction company insolvency also has a strong influence on other industries. Prediction models addressing the insolvency of construction company have been well studied. Although factors contributing to insolvency must precede those of predictions of insolvency, studies on these contributing factors are limited. The purpose of this study is to analyze the influence of changes in the housing market on construction company insolvency by using the Vector Error Correction Model. Construction companies were divided into two groups, and the expected default frequency(EDF), which indicates insolvency of each company was measured through the KMV model. The results verified that 10 largest construction companies were in a better financial condition compared to relatively smaller construction companies. As a result of conducting impulse response analysis, the EDF of large companies was found to be more sensitive to housing market change than that of small- and medium-sized construction companies.

• Therapeutic Science for Rehabilitation
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• v.8 no.4
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• pp.41-51
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• 2019

Objective : The purpose of this study was to investigate the effects of virtual reality-based activities of daily living (ADL) training on ADL and rehabilitative motivation in patients with traumatic brain injury. Methods : This study was performed using a pre-post design with seven traumatically brain injured patients. Subjects were subjected to virtual reality-based ADL training for 30 minutes a day, 2 to 3 times a week for 4 weeks. Evaluation was conducted before and after the intervention using the Korean Modified Barthel Index (K-MBI), Cognitive Functional Independence Measure (C-FIM), and Volitional Questionnaire (VQ). Changes before and after intervention were analyzed by Wilcoxon signed-rank test, and correlations were analyzed using Spearman's coefficient. Results : After intervention, patients with traumatic brain injury showed significant improvements in K-MBI (p<.05). There was no significant change in total C-FIM score and VQ score (p>.05). Total C-FIM score correlated significantly with VQ score (p<.05, r=.755). The social cognition domain of C-FIM had a significant correlation with VQ score (p<.05, r=826). Conclusions : Virtual reality-based ADL training can improve ADL performance, but further research is needed to determine whether improvements in social cognition and rehabilitative motivation are possible.

• Therapeutic Science for Rehabilitation
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• v.10 no.2
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• pp.95-108
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• 2021

Objective : This study aimed to develop prototypes of "smart stacking cones" by combining ICT to evaluate and train the upper extremity function and dual task performance in patients with central nervous system impairment, and to identify the complementary point to the completion of the device through a usability test. Methods : This prototype comprised of a hardware and software system that enabled the evaluation and training of patients and the management of data obtained from patients' performance. Specific measurement variables were established so that patient performance could be measured correctly. Based on the measurement variables, a the prototype included a 'single task evaluation modes', 'dual task evaluation mode', 'single task training mode', and 'dual task training modes'. Additionally, a usability test was conducted to assess clinical applicability and overall satisfaction for the prototype. Results : The results of the usability test were generally found to be appropriate. The 'content adequacy' in the usability test was the area with the highest level of adequacy and the lowest level of inadequacy. Additionally, overall 'satisfaction' in the usability test was the area with the highest appropriate and inappropriate levels. Hence, the overall satisfaction results were unstable. Conclusion : Future studies should be conducted to identify the clinical effectiveness of the device by applying an upgraded smart stacking cone to an actual patient group.