• Membrane Journal
• /
• v.32 no.6
• /
• pp.367-382
• /
• 2022

Numerous metal-organic frameworks (MOFs) produced by periodic combinations of organic ligands and metal ions or metal-oxo clusters have led the way for the creation of energy-efficient membrane-based separations that may serve as viable replacements for traditional thermal counterparts. Although tremendous progress has been made over the past decade in the synthesis of polycrystalline MOF membranes, only a small number of MOFs have been exploited in the relevant research. Intercrystalline defects, or nonselective diffusion routes in polycrystalline membranes, are likely the reason behind the delay. Postsynthetic modifications (PSMs) are newly emerging strategies for providing polycrystalline MOF membrane diversity by leveraging advanced membranes as a platform and improving their separation capabilities via physical and/or chemical treatments; therefore, neither designing and developing MOFs nor tailoring membrane synthesis techniques for focused MOFs is necessary. In this minireview, seven subclasses of PSM techniques that have recently been adapted to polycrystalline MOF membranes are outlined, along with obstacles and future directions.

• Journal of the Korea Society for Simulation
• /
• v.18 no.2
• /
• pp.29-38
• /
• 2009

In the computing environment with heterogeneous resources, a job scheduling model is necessary for effective resource utilization and high-speed data processing. And, the job scheduling model has to cope with a dynamic change in the condition of resources. There have been lots of researches on resource estimation methods and heuristic algorithms about how to distribute and allocate jobs to heterogeneous resources. But, existing researches have a weakness for system compatibility and scalability because they do not support the standard language. Also, they are impossible to process jobs effectively and deal with a variety of computing situations in which the condition of resources is dynamically changed in real-time. In order to solve the problems of existing researches, this paper proposes a semantic computing-based dynamic job scheduling model that defines various knowledge-based rules for job scheduling methods adaptable to changes in resource condition and allocate a job to the best suited resource through inference. This paper also constructs a resource ontology to manage information about heterogeneous resources without difficulty as using the OWL, the standard ontology language established by W3C. Experimental results shows that the proposed scheduling model outperforms existing scheduling models, in terms of throughput, job loss, and turn around time.

• The Mathematical Education
• /
• v.62 no.3
• /
• pp.363-380
• /
• 2023

This study analyzed the difficulties and mathematical modeling knowledge improvement that an elementary school teacher experienced in modifying a mathematics textbook task to a mathematical modeling task. To this end, an elementary school teacher with 10 years of experience participated in teacher-researcher community's repeated discussions and modified the average task in the data and pattern domain of the 5th grade. The results are as followings. First, in the process of task modification, the teacher had difficulties in reflecting reality, setting the appropriate cognitive level of mathematical modeling tasks, and presenting detailed tasks according to the mathematical modeling process. Second, through repeated task modifications, the teacher was able to develop realistic tasks considering the mathematical content knowledge and students' cognitive level, set the cognitive level of the task by adjusting the complexity and openness of the task, and present detailed tasks through thought experiments on students' task-solving process, which shows that teachers' mathematical modeling knowledge, including the concept of mathematical modeling and the characteristics of the mathematical modeling task, has improved. The findings of this study suggest that, in terms of the mathematical modeling teacher education, it is necessary to provide teachers with opportunities to improve their mathematical modeling task development competency through textbook task modification rather than direct provision of mathematical modeling tasks, experience mathematical modeling theory and practice together, and participate in teacher-researcher communities.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.5
• /
• pp.587-599
• /
• 2023

As climate change increasesthe frequency and risk of flooding in major cities around theworld, the importance ofsimulation technology that can quickly and accurately analyze high-resolution 2D flooding information in large-scale areasis emerging. The physically-based approaches based on the Shallow Water Equations (SWE) often requires huge computer resources hindering high-resolution flood prediction. This study investigated the theoretical background of Weighted Cellular Automata 2D (WCA2D), which simulates spatio-temporal changes offlooding using transition rules and weight-based system, and assessed feasibility to simulate pluvial flooding in the urbancatchment, theOncheon-cheon catchmentinBusan, SouthKorea.Inaddition,the computation performancewas compared by applying versions using OpenComputing Language (OpenCL) andOpenMulti-Processing (OpenMP) parallel computing techniques. Simulationresultsshowed that the maximuminundation depthmap by theWCA2Dmodel cansimilarly reproduce historical inundation maps. Also, it can precisely simulate spatio-temporal changes of flooding extent in the urban catchment with complex topographic characteristics. For computation efficiency, parallel computing schemes, theOpenCLandOpenMP, improved the computation by about 8~14 and 5~6 folds respectively, compared to the sequential computation.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.3
• /
• pp.1-11
• /
• 2009

XQuery query proposed by W3C is one of the standard query languages for XML data and is widely accepted by many applications. Therefore the studies for efficient Processing of XQuery query have become a topic of critical importance recently and the optimization of XQuery query is one of new issues in these studies. However, previous researches just focus on the optimization techniques for a specific XML data management system and these optimization techniques can not be used under the any XML data management systems. Also, some previous researches use predefined XML data structure information such as XML schema or DTD for the optimization. In the real situation, however applications do not all refer to the structure information for XML data. Therefore, this paper analyzes only a XQuery query and optimize by using itself of the XQuery query. In this paper, we propose 3 kinds of optimization method that considers the characteristic of XQuery query. First method removes the redundant expressions described in XQuery query second method replaces the processing order of operation and clause in XQuery query and third method rewrites the XQuery query based on FOR clause. In case of third method, we consider FOR clause because generally FOR clause generates a loop in XQuery query and the loop often rises to execution frequency of redundant operation. Through a performance evaluation, we show that the processing time for rewritten queries is less than for original queries. also each method in our XQuery query optimizer can be used separately because the each method is independent.

• The Mathematical Education
• /
• v.62 no.4
• /
• pp.531-549
• /
• 2023

Despite the significance of mathematics teacher guidebooks as a support for teacher learning, there are few studies that address how elementary mathematics teacher guidebooks support teacher learning. The purpose of this study was to analyze the educative features of elementary mathematics teacher guidebooks for grades 3 and 4. For this, six units from each of ten kinds of teacher guidebooks were analyzed in terms of seven dimensions of Teacher Learning Opportunities in Korean Mathematics Curriculum Materials (TLO-KMath). The results of this study showed that mathematics content knowledge for teaching was richly provided and well organized. Teacher guidebooks provided teacher knowledge to anticipate and understand student errors and misconceptions, but were not enough. Sample dialogues between a teacher and students were offered in the teacher guidebooks, making it easier for teachers to identify the overall lesson flow and key points of classroom discourse. Formative assessment was emphasized in the teacher guidebooks, including lesson-specific student responses and their concomitant feedback examples per main activity. Supplementary activities and worksheets were provided, but it lacked rationales for differentiated instruction in mathematics. Teacher knowledge of manipulative materials and technology use in mathematics was provided only in specific units and was generally insufficient. Teacher knowledge in building a mathematical community was mainly provided in terms of mathematical competency, mathematical classroom culture, and motivation. This paper finally presented implications for improving teacher guidebooks to actively support teacher learning.

• Journal of Navigation and Port Research
• /
• v.48 no.3
• /
• pp.155-163
• /
• 2024

As the demand for reducing carbon emissions increases, efforts to reduce the usage of fossil fuels and research on renewable energy are also increasing. Among the various renewable energy harvesting techniques, the floating offshore wind turbine has several advantages. Compared to other technologies, it has fewer installation limitations due to interference with human activity. Additionally, a large wind turbine farm can be constructed in the open ocean. Therefore, it is important to conduct motion analysis of floating offshore wind turbines in waves during the initial stage of conceptual design. In this study, a frequency motion analysis was conducted on a semi-submersible type floating offshore wind turbine. The analysis focused on the effects of varying trim on the motion characteristics. Specifically, motion response analysis was performed on heave, roll, and pitch. Natural period analysis confirmed that changing the trim angle did not significantly affect the heave and pitch motions, but it did have a regular impact on the roll motion.

• Journal of Technology Innovation
• /
• v.32 no.2
• /
• pp.23-58
• /
• 2024

Despite the important roles of institutions and their collaboration in producing knowledge for innovation, the lack of accurate methods for identifying such knowledge-producing institutions has restricted empirical research on the role of institutions in innovation. This study explores methods to enhance the accuracy of identifying institutions involved in innovation process. To this end, we propose ways to improve accuracy in both aspects of information - data and algorithms - using bibliographic information in the digital health field. Specifically, in the data processing stage before applying algorithms, we address contextual inaccuracies of bibliographic information; in the algorithm application stage, we propose methods to improve the ambiguity of institution names (IND). When compared with the PKG dataset, which is publicly available datasets based on the same bibliographic information, our methods doubled the number of cases available for subsequent analysis. We also discovered that the contribution of Korean institutions in the digital health field is either underestimated or overestimated. The method presented in this study is expected to contribute to empirically researching the role of knowledge-producing institutions in innovation process and ecosystem.

• Journal of the International Relations & Interdisciplinary Education
• /
• v.4 no.2
• /
• pp.1-19
• /
• 2024

This study examined the effects of creative musical on school adaptation and self-efficacy improvement of school maladjusted adolescents. The subjects of this study were 229 students classified as suspected school maladjustment groups through Wee class counselors and students who were judged as at-risk groups as a result of the emotional behavioral evaluation test conducted by the Office of Education. The study period consisted of 100 minutes per session once a week from May 1st to October 31st, 2023, and a total of 15 sessions were held. To verify the effectiveness, a self-efficacy scale (SES) of Kim A-young (2002)'s school adaptation scale and Sherer et al. (1982) was conducted before and after the creative musical, and the results were analyzed through the corresponding t-test. As a result of the study, the subject's school adaptation (p<.05) and the sub-factors of companionship (p<.05), school class (p<.05), and school rules (p<.05) all increased and were statistically significant after the creative musical compared to before. The subject's self-efficacy (p<.01) and the sub-factors of the study, general self-efficacy (p<.01), and social self-efficacy (p<.05) also increased and were statistically significant after the creative musical compared to before it was conducted. Therefore, this study revealed that creative musicals are effective in improving school adaptation and self-efficacy of school maladjusted adolescents.

• Journal of Nutrition and Health
• /
• v.41 no.7
• /
• pp.621-633
• /
• 2008

Diabetes mellitus (DM) is a well-established independent risk factor for cerebral infarction (CI). Additionally, the DM as well as CI are influenced significantly by health-related behaviors and diets. The aim of this study was to compare the food habits, nutrient intakes, and dietary patterns and quality in DM patients with CI (DM-CI) and without CI. This study was accomplished with 68 subjects (DM-CI group = 28, DM group = 40). Health-related behaviors, food habits, nutrient intakes and dietary quality were investigated. As a result, the mean ages and durations of diabetes in DM-CI and DM groups were $65.6{\pm}9.2$, $10.9{\pm}8.5$ and $69.2{\pm}3.0$, $9.7{\pm}8.4$ years, respectively. The health-related behaviors such as, smoking, alcohol drinking, and regular exercising in both groups were significantly different (p < 0.05) showing the number of subjects who were smoking and drinking alcohol was significantly higher in DM-CI group and the opposit result was seen for exercise. In male subjects, the intake of carbohydrate and sodium of DM-CI group were significantly higher than those of DM group (p < 0.05). In female subjects, the intake of calorie, carbohydrate, fat, sodium, and cholesterol were significantly higher in the DM-CI group (p < 0.05). Daily intake of vitamin $B_1$, vitamin $B_2$, folate, vitamin C, and calcium were significantly higher in DM group (p < 0.05). In the comparison with the dietary reference intake for Koreans (KDRI), vitamin $B_1$, vitamin $B_2$, folate, and calcium intakes were lower in DM-CI group whereas calcium and zinc intakes were in DM group. Moreover, index of nutritional quality (INQ) of vitamin $B_1$, vitamin $B_2$, vitamin C, folate, and calcium were lower significantly in DM-CI group (p < 0.05). Dietary quality including dietary diversity score (DDS), GMVDF (grain, meat, vegetable, dairy, fruit), and dietary quality index (DQI) was significantly lower in DM-CI group (p < 0.05). According to the results, diabetic mellitus patients accompanied by cerebral infarction had poorer eating patterns and dietary quality in accordance with poorer health-related behaviors compared with the DM patients without CI.