• YAKHAK HOEJI
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• v.60 no.2
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• pp.92-99
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• 2016

Parkinson's disease (PD) is one of the representative neurodegenerative movement disorders with the selective loss of dopaminergic neurons in the substantia nigra. 6-Hydroxydopamine (6-OHDA) is widely used as an experimental model system to mimic PD and has been reported to cause neuronal cell death via oxidative and/or nitrosative stress. Therefore, daily intake of dietary or medicinal plants which fortifies cellular antioxidant capacity can exert neuroprotective effects in PD. In the present study, we have investigated the protective effect of Korean red ginseng (KRG) against 6-OHDA-induced nitrosative death in C6 glioma cells. Treatment of C6 cells with 6-OHDA decreased cell viability and increased expression of inducible nitric oxide synthase, production of nitric oxide as well as peroxynitrite, and formation of nitrotyrosine. 6-OHDA led to apoptotic cell death as determined by decreased Bcl-2/Bax, phosphorylation of JNK, activation of caspase-3, and cleavage of PARP. Conversely, pretreatment of C6 cells with KRG attenuated 6-ODHA-induced cytotoxicity, apoptosis, and nitrosative damages. To further elucidate the molecular mechanism of KRG protection against 6-OHDA-induced nitrosative cell death, we have focused on the cellular self-defense molecules against exogenous noxious stimuli. KRG treatment up-regulated heme oxygenase-1 (HO-1), a key antioxidant enzyme essential for cellular defense against oxidative and/or nitrosative stress via activation of Nrf2. Taken together, these findings suggest KRG may have preventive and/or therapeutic potentials for the management of PD.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.685-694
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• 2015

In the present study, we conducted in-depth interviews with school dieticians and nutrition teachers to determine the local foods they were aware of and their experiences with local foods. We also aimed to obtain more detailed measures for local food vitalization and suggestions for improvements. In-depth interviews were performed with 8 school dieticians and nutrition teachers, who stated that local food vitalization was needed for school food services, because it could be a foundation for securing safefood products, student healthi mprovements, environmental protection, and the establishment of a general consumption market. However, they were aware of a higher number of disadvantages than advantages in school situations and indicated the deterioration of the quality of food products as the biggest disadvantage. The most-suggested measurement items for local food vitalization in schools included improvement of the food distribution system, expansion of education, information sharing, prevention of monopolies, improvement of food-product quality, and mass production. In addition, it was suggested that school dieticians and nutrition teachers should invest efforts in the development of excellent recipes and varied diets utilizing local foods. Therefore, system supplementation is urgently required in order for school food service officials, and consumers, to efficiently introduce and vitalize local foods. It is also necessary to foster an environment that encourages trust-based relationships with producers to maximize the effect of system supplementation. This would be the foundation for improving the health of students, improving food-service quality, nutrition management, and vitalization of the regional economy in the future, and will positively affect students' food consumption patterns even after they become adults.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.97-105
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• 2011

In rivers and streams, biofilms are thin layers of greenish-brown slime attached to rocks, plants, and other surfaces. Biofilms play key roles in primary production and cycling of nutrients, water quality remediation, suspended sediment removal, and energy flow to higher trophic levels. In the present study, we developed a two-dimensional cellular automata model to simulate mixed biofilms of toxin-sensitive and toxin-producing species in hydrodynamic flow. The flow was generated by a stochastic process for uniform flow and by using the Navier-Stokes equation for non-uniform flow. Minimized local rules governing reproduction and mortality of the species were executed in the self-organizing processes to elucidate interactions between toxin-producing and toxin-sensitive species in competition over nutrients. We briefly discuss the morphology of the simulated biofilm under different flow conditions.

• The Research Journal of the Costume Culture
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• v.23 no.2
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• pp.337-352
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• 2015

This study suggests designs of maternity clothes wearable after childbirth and aims at confirming that maternity wear is continuously wearable during a post-natal period. As for research methods, theoretical and empirical studies with research on a production of work were conducted, focusing on the design development of the maternity dress which may be worn even after childbirth. The results of theoretical and empirical studies possibly presented various designs which require fashionability going with the trend of time. The maternity wear also requires the adaptability for a changing body shape to enable a woman to wear it during a pregnancy period and after childbirth. Besides, the convenience of dressing and undressing with wearing comfort is considered. 6 sets of one-piece dress were made as the result of the study and three factors of fashionability, adaptability and convenience were considered. The conclusions are as follows : Firstly, it verified that the maternity wear is fashionable clothes not to cover protruded abdomen but to satisfy women's desire of self expression. Secondly, it overcame the limit of dress design through fitting it to completely different two body sizes and shapes with design factors and patterns. Lastly, it suggested a research model of maternity wear corresponding to economical, environmental and ethical principles as giving an effect of "two" dresses with one. This study presented a new direction of design study with meaningful actions of fashion designing in the aspects of economical, environmental and ethical consumption unlike artificial disposal on SPA brands.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.1-10
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• 2016

Flux Cored Wire is the most widely used welding material for Flux Cored Arc Welding these days. This paper introduces the technical aspects of manufacturing FCW and the development trend of FCW for each type of steel and metal. The studies are ongoing to lower the production cost of seamless-type FCW since it has not been generally used in welding shops so far because of it high cost even though the seamless-type FCW has various advantages than folded-type FCW in terms of manufacturing technology. Meanwhile, a technical research has been carried out to develop a rutile type of FCW products which satisfies high toughness after post heat treatment. In addition, for high-speed fillet welding, there has been a development of welding materials which can be welded in Single Auto-Carriage 100 cpm or more and up to Twin Tandem 200 cpm without occurring any welding defect in order to improve the welding productivity. As Zn coated steel is being used recently to improve the corrosion resistance of the automotive parts, a research and development for Metal Cored Wire has been conducted to reduce the Si island produced in welding operation than those produced when using the former solid wires. A development of welding material that guarantees CTOD performance beyond $-40^{\circ}C$ CTOD to $-60^{\circ}C$ is underway by different steel grades, and FCW for super austenitic stainless steel is being developed as the corrosion resistant steel has been upgraded.

• Journal of Plant Biology
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• v.36 no.2
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• pp.159-170
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• 1993

We investigated the effects of maternal and paternal parentage, and ovule position in a pod on seed development, weight, and progeny performance, using an annual crop commonly called cowpea (Vigna unguiculata L.). The experiment was conducted in a greenhouse. Nine maternal parents were randomly selected, and 3 individuals were chosen as paternal parents based on the male fitness components. Five types of hand-pollination were attempted on each flower of the maternal plants to evaluate the influence of paternal identify. Independent variables such as parentage and ovule position affected the pattern of seed development. Ovules in the middle position of the pod exhibited a much higher probability of seed maturation than those at the stylar and basal positions, confirming the position effect. These independent variables also appeared to exert a significant effect on seed weight, although it was not possible to evaluate the relative importance of those variables due to a significant interaction between parents. Mixed pollination tended to yield heavier seeds than other paternal parents. Ovules in the middle and basal end positions produced heavier seeds than those at the stylar end regardless of maternal and paternal parentage. Seed weight was independent of all measurements of progeny performance. At week 2 after germination significant paternal effects were found to be mediated through the ovule position in a pod. In particular, the progeny derived from self-pollination performed worse than the progeny from other paternal parentage. The progeny performance at week 4 after germination was affected by maternal parents independently of seed weight. These results show that paternal and maternal effects were quite consistent from the seed development to early growth of the progeny. Consequently, maternal and paternal effects on seed development and weight, and progeny performance may reflect, at least to some extent, genetic contribution of both parents. If so, it is possible for sexual selection on maternal and paternal function to generate the evolution of reproductive traits related to seed production.

• Journal of IKEEE
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• v.21 no.3
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• pp.252-255
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• 2017

$Mo_xW_{1-x}Si_2$ heaters were fabricated by self-propagating high-temperature synthesis (SHS) process and post sintering process. To validate the reliability of the $Mo_xW_{1-x}Si_2$ heaters, the accelerated life test (ALT) was conducted, and then lifetime to $Mo_xW_{1-x}Si_2$ heaters was estimated by using Minitab programs. Also, the failure analysis of $Mo_xW_{1-x}Si_2$ heaters after ALT was performed through electrical and structural properties. As the results, it was confirmed that the dominant failure mode of $Mo_xW_{1-x}Si_2$ heaters is the crack formation in heaters and the delamination of protective $SiO_2$ layers.

• Hwankyungkyoyuk
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• v.23 no.2
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• pp.97-112
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• 2010

The study aims to comprehend the effect of the wetland ecology education on the elementary school students' changes of recognition about wetland through the wetland ecology map program. In this study, the literary research, the experimental research and the survey methods were operated. Through the literary research, the environmental factors were extracted, and the writing item of ecology map was reconstructed based on the literary research, so the experimental research was operated with the wetland ecology map program. Through four areas of test items such as the information and knowledge, values and attitudes, development and conservation, behavior and participation, and the analysis of children's study results, the effect of the wetland ecology map program on changes of recognition about wetland was verified quantitatively and qualitatively. Wetland ecology map program would be able to be an educational approach which can achieve the 'personalization of environment' setting up predictable environmental improvement goals and satisfying the needs of spatial information of the appropriate regions from the holistic perspective that students themselves plan and participate beyond a one-time experience program. Production of ecological map through continuous monitoring is expected to improve the possibility of subjective environmental actions by operating self-directed learning. Based on the conclusion of this study, we would suggest the following. For wetland ecology map program to be supplemented and utilized, the basic education of wetland should be organized in regular school curriculum, ecology map program including various teaching learning methods be prepared actively, and in future studies, studies of ecosystem-wide wetland ecology map program including animals like birds and fish are necessary.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.3
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• pp.109-117
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• 2013

This study designed a "Diagnostic Model for Management Innovation of Medium Enterprises" based on the theoretical background of success factor and management diagnosis model for management innovation of medium enterprises and suggested a measure for utilization of strategic subject and diagnostic model that enterprises can apply. Utilization of medium enterprises management innovation diagnostic model designed through this study would be of help for making a diagnosis of the capability maturity level of enterprises' current management system and improving it by establishing a challenging capability objective and building a circulation system capable of innovating enterprises. It is expected for enterprises to overcome growing pains and establish a management system capable of achieving outcome (productivity) by repeating measurement and innovation through management diagnosis. In addition, this study provides a method to produce a strategic subject, select priority of implementation and prepare an implementation road map by classifying and filtering management issues produced as a result of management diagnosis in a systematic way. If variables necessary for production of an objective weighted value of scoring and discover of elements for category of diagnostic model and elementary items as well as design of a self-diagnosis questionnaire, measurement of management outcome suggested in this study can be able to be verified and supplemented through case study in the future, it is expected to make the degree of completion as a diagnostic model elevated that may help for growth and development through innovation of medium enterprises.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.38-43
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• 2007

This paper describes ultrasonically assisted grinding used to obtain a glossy surface quickly and precisely. High-quality surfaces are required for plastic injection molding dies used in the production of plastic parts such as dials for cellular phones. Traditionally, in order to finish the dies, manual polishing by a skilled worker has been required after the machining processes, such as electro discharge machining (EDM), which leaves an affected layer, and milling, which leaves tooling marks. However, manual polishing causes detrimental geometrical deviations of the die and consumes several days to finish a die surface. Therefore, a machining process for finishing dies without manual polishing to improve the surface roughness and form accuracy would be extremely valuable. In this study, a 3D positioning machine equipped with an ultrasonic spindle was used to conduct grinding experiments. An electroplated diamond tool was used for these experiments. Generally, diamond tools cannot grind steel because of excessive wear as a result of carbon atoms diffusing into bulk steel and chips. However, ultrasonically assisted grinding can achieve a fine surface (roughness Rz of $0.4{\mu}m$) on die steel without severe tool wear. The final aim of this study is to realize mirror surface grinding for injection molding dies without manual polishing. To do this, it is necessary to fabricate an electroplated diamond tool with high form accuracy and low run-out. This paper describes a tool-making method for high precision grinding and the grinding performance of a self-electroplated tool. The ground surface textures, tool performance and tool life were investigated A ground surface roughness Rz of 0.14 um was achieved Our results show that the spindle speed, feed rate and cross feed affected the surface texture. One tool could finish $5000mm^2$ of die steel surface without any deterioration of the ground surface roughness.