• Polymer(Korea)
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• v.37 no.4
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• pp.486-493
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• 2013

The structure, morphology, and physical properties of syndiotatic poly(vinyl alcohol) (s-PVA) gel spun fibers were investigated to prepare polymeric embolization coils. S-PVA was prepared by saponification of the poly(vinyl acetate)/poly(vinyl pivalate)(PVAc/PVPi) copolymer. The viscosity of s-PVA solutions showed shear thinning behavior and the solution formed a homogeneous phase. Based on shear viscosity change with concentration, the optimum dope concentration was selected as 13 wt%, after which s-PVA fibers were spun and the solvent was removed. The fibers were then drawn with a maximum draw ratio of 15. A polymeric embolization coil was made of the s-PVA gel-spun fibers. The fibers were wound densely onto rigid rod and then annealed at different annealing temperatures. The polymeric embolization coil annealed at $200^{\circ}C$ was similar to metallic coils and its shape was maintained well after extension. Overall, gel-spun PVA fibers performed well for the preparation of primary and secondary coils to replace metallic coils.

• Fire Science and Engineering
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• v.28 no.3
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• pp.72-79
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• 2014

The purpose of this study is to draw the improvement plan through the analysis of problems of main stretchers that are being used by the 119 EMS. In order to find out the problems, we used the literature review and analysis, survey questionnaire and we also made full use of KJ method (Kawakita Jiro method, affinity diagram), graph method, and priority matrix method to produce the improvement indicators. The problems of main stretchers are summarized as follows. they are being recognized as part of the emergency vehicle, they have the imperfection of performance verification criteria, and they cause the injuries of paramedics and patients accidents in operation. The indicators such as the ease of operation, the high performance, the multi-function, the driving performance, the durability and the lightweight, was produced to improve the problems. The results of the interconnection analysis and the applying priority matrix method on the indicators are the ease of operation ${\rightarrow}$ the multi-function ${\rightarrow}$ the driving performance ${\rightarrow}$ the high performance ${\rightarrow}$ the durability and the lightweight in order of importance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.56-63
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• 2016

For air express service providers offering various express delivery services such as overnight delivery and next-business day delivery services, establishing quickly cargo loading plans is one of important issues owing to the characteristics of air express business, i.e., a short amount of time is available to complete all cargo loading operations before flight departure after receiving air express containers, pallets and bulks. On the other hand, one of major concerns in the air cargo loading planning is to make a plan that insures the stability of an aircraft to avoid take-off, flight, and landing accidents. To this end, this paper considers an air cargo loading planning problem, which is the problem of determining locations in the aircraft cargo space where air containers, pallets and bulks to be loaded while insuring the aircraft stability, motivated from DHL and Air Hong Kong. The objective of the problem is to maximize the total revenue gained from loading air express containers, pallets and bulks. To solve the problem, this paper suggests a simulated annealing algorithm to overcome impracticality of the integer programming model developed by a previous study requiring excessive computation time. The results of computational experiments show that the heuristic algorithm is a viable tool for establishing express cargo loading plans as giving robust and good solutions in a short amount of computation time. Scenario analyses are performed to investigate the effect of the current activities of air express carriers on the revenue change and to draw practical implications for air express service providers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.638-640
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• 2010

The business of companies has become more fierce due to the age of limitless competition. In addition, to improve the service satisfaction of their customers, they have continued their efforts. The researches about making their efforts get profits have done. As a result, CRM(customer relationship management) which is appropriate to analysis, evaluate and draw one of solutions to satisfy customers is received attention. Therefore, in this material we consider a architecture for keyword extraction system which is a kind of necessary technology for e-business model to provide a differentiated service. And then we could get the know-how of customer acquisition and maintenance.

• The Journal of Korean Association of Computer Education
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• v.18 no.1
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• pp.81-97
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• 2015

Although Flipped Classroom(FC) which has recently attracted attention of educational field, showed its various educational effects such as learning academic achievement, attitude, collaborative learning and self-regulated learning. other studies also showed a number of significant problems and challenges in practically implementing. Thus, this study aims to investigate in-service and pre-service teachers awareness of FC in order to explore its educational feasibility for successfully adopting it to classrooms through the alternative solutions to its limitations. To achieve this goal, we firstly conducted literature review on teaching and learning models and guidelines to draw educational prerequisites and then analyzed needs of 156 pre-service teachers and 42 in-service teachers. According to survey results, 80% of teachers are willing to apply FC to their classes and hope to be offered with pre-learning activity materials and guidelines. They consider junior high school students and college students as appropriate learners, social science, science, Korean, and English as suitable subjects, and video content as optimal materials for pre-learning activities.

• Archives of design research
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• v.16 no.1
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• pp.73-82
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• 2003

This paper presents a case study of designing the stroller and its renting system for department stores in order to verify the feasibility of the participatory design approach, in particular the concept generation toolkits and the participatory design workshops, in the product development process. As the concept generation toolkits to draw active user participation, a Velcro Covered stroller model and a Block Layout System were developed and used in a series of the participatory design workshops. The results suggest that the participatory design approach provides better understanding of what the users want and allows designers to avoid false expectation about the design context. It was also found that the experience of design team with the users in the workshop was a good source of design ideation. The study also suggests that participatory design approach can become more effective by developing the concept generation toolkits which are more appropriate for design problems and the methods to smoothly transform the concepts from users into synthesized design solutions.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.8
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• pp.1178-1187
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• 2006

The purpose of this study is to conduct a questionnaire survey on the actual conditions of the working uniform and protective equipment put on by street cleaners, then to identify their inconvenience and problems and to draw solutions to improve them, and finally to design a spring-and-autumn street cleaner uniform which has enhanced functionalities such as motional flexibility, safety and soil proof. The questionnaire survey of this study was done by street cleaners who were in charge of street cleaning and collecting the recyclable waste. The result of this study, easily worn-out parts of the working clothing were the sleeve hems and the front part on the upper uniform, and the trouser hems and zipper on the lower uniform. Easily soiled parts were the sleeve hems, parts of arm on the upper uniform, and the trouser hems and knee parts on the lower uniform. Based on the results of the questionnaire survey, the sample uniforms were designed in consideration of material, design and pattern. A soil-proof material was used for easily soiled parts such as sleeve hems, knee parts and trouser hems. Reflective material was applied to the parts such as chest, back and the side lines of sleeves and trousers to raise visibility in working and to ensure safety. A crease was given to each side of the back. The height of sleeve cap was lowered to lift the motional flexibility of back and arm parts. Darts were applied to elbow and knee parts for a three-dimensional design. Gussets were inserted in the thigh part to give it activity. Then quantitative evaluation and a sensory evaluation, which was composed of outward appearance, motional flexibility and fitness for field operation, were conducted. According to these evaluations, the sample uniform was found to be more satisfactory than current uniform.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.303-310
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• 2017

Pressure retarded osmosis(PRO) has attracted much attention as potential technology to reduce the overall energy consumption for reverse osmosis(RO) desalination. The RO/PRO hybrid process is considered as the most logical next step for future desalination. The PRO process aims to harness the osmotic energy difference of two aqueous solutions separated by a semipermeable membrane. By using the concentrated water(RO brine) discharged from existing RO plants, the PRO process can effectively exploit a greater salinity gradient to reduce the energy cost of processing concentrated water. However, in order to use RO brine as the draw solution, PRO membrane must have high water flux and enough mechanical strength to withstand the high operational pressure. This study investigates the development of a thin film composite PRO membrane and spiral wound module for high power density. Also, the influence of membrane backing layer on the overall power density was studied using the characteristic factors of PRO membranes. Finally, the performance test of an 8-inch spiral wound module was carried out under various operating conditions(i.e. hydraulic pressure, flow rate, temperature). As the flow rate and temperature increased under the same hydraulic pressure, the PRO performance increased due to the growth of water permeability coefficient and osmotic pressure. For a high performance PRO system, in order to optimize the operating conditions, it is highly recommended that the flow pressure be minimized while the flow rate is maintained at a high level.

• Korean Journal of Biological Psychiatry
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• v.21 no.4
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• pp.118-127
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• 2014

Along with language, socialization is a unique feature of the human being. There is a continuous debate regarding whether the development of socialization is innate, and conducted by the environment in the growing process, or the result of the interaction of both aspects. If socialization is the result of the interaction with the environment or is an acquired developmental process, the following question rises. "Is there a 'critical period' for the development of socialization?" Although there are a huge number of studies seeking for treatment and solutions for developmental delay or deficits of socialization, it is very complicated question to answer. Historical figures such as 'Hugh Blair' of Borgue in England, and 'the wild boy of Aveyron' in France, seem to have innate socialization deficits. Nowadays patients with non-verbal learning disorder, social communication disorder, or autism spectrum disorder seem to have genetic defects. On the other hand, Harry Harlow's monkey experiments, hikikomori of Japan, Romanian orphans and patients with reactive attachment disorder seem to display social deficits due to environmental factors. However, it is not easy to clearly draw a line between innate or acquired factors. Therefore, rather than subdividing the diseases for etiological and pathophysiological approach to heterogenous groups with the common denominator of social deficit, and for the research of pathophysiology and treatment development, the authors suggest a comprehensive concept of "social dysfunction spectrum."

• Korean Institute of Interior Design Journal
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• v.24 no.5
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• pp.21-30
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• 2015

The visual expression system of space realized in Baroque aesthetics is basically grounded on the philosophical view to the world of the time, that is to say the changes of the thinking system in the Renaissance and ontology based on it. Structural aesthetics in Baroque freed from Plato's system of harmony but grounded on Leibniz's process philosophy formed a crucial background to highlight the formal nature of the whole and build a structure based on the inclusive principle of formativity. Also, to solve problems to realize the order and consistency of forms from the whole, Baroque adopted the nonlinear and nonphysical formative system as the principle of building space in works of art. Combining the order system of nature in the Renaissance with manneristic dynamicity as well as formative principle taking shape geometrically, it did establish a variety of aesthetic concepts based on the results of infiniteness and exaggeration expressed from the two forces, the Renaissance and mannerism. This study has found that such Baroque aesthetics did overcome classical planeness and draw continuous mobility from the structures and forms based on that with the transborder concepts of structures, the components of space, as an ultimate system of formative expression. Moreover, this author has drawn and analyzed with the cases of the 17th-century art and architecture the transborder elements manifesting the nature of diverse formative visual elements produced in artistic expressions with that principle of aesthetics, that is the intangible concept of Baroque. Based on that, this researcher intends to come up with technical solutions to solve a lot of environmental and architectural problems we are severely facing nowadays in terms of environmental, physical, and emotional aspects with the theoretical clues and results acceptable to this contemporary era.