• Animal cells and systems
• /
• 제6권3호
• /
• pp.187-193
• /
• 2002

It has long been recognized that exposure to low levels of toxic chemicals could have beneficial effects, such as increased resistance to related chemicals or stimulation of growth or development. The notion of radiation hormesis, that exposure to low levels of ionizing radiation could produce beneficial effects, developed seriously in the late 1950’s, and was, to most radiation scientists, incredible. This was due in pan to the then prevailing ideas of radiobiological mechanisms, in part to the sweeping generalizations made by the leading proponents of the radiation hormesis concept, and in pan to the many failures to confirm reports of beneficial effects. More recent understanding of the mechanisms of radiation damage and repair, and discoveries of induction of gene expression by radiation and other genotoxic agents [the adaptive response] make it seem inevitable that under suitable conditions, irradiation will produce beneficial effects.

• Safety and Health at Work
• /
• 제6권2호
• /
• pp.143-145
• /
• 2015

Three occupational safety and health (OSH) activities, one international and two national workshops, were documented as part of OSH activities conducted under the International Labor Organization/Korea Partnership Program in the year 2011-2012. This study aimed to provide information on what the three OSH activities were implemented and how they contributed to the improvement of OSH in Asian countries. The international workshop was useful for the participants to understand a variety of information on OSH as well as participatory action-oriented training (PAOT) approaches at the regional and global levels. The two national workshops were practical for participants to strengthen their knowledge and skills on the PAOT at the enterprise and national levels. The study shows that the three OSH activities contributed to the understanding of the participants on OSH and PAOT, and that the activities promoted the improvement of OSH across countries in Asia.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
• /
• pp.115-120
• /
• 1998

Aerodynamic noise generated by automobile cooling fan is investigated. Automobile cooling fans radiate both discrete frequency noise as well as broadband noise. In the present work, the former is considered through free-wake panel method coupled with acoustic analogy fully considering the retarded time variation on the blade surface, while the latter is taken into account by three well-established broadband noise components. Experiments were performed to supplement necessary inputs as well as to provide the final comparison with the predicted noise spectrum. The predicted noise levels at blade passing frequencies agree well with the experimental data for the first few harmonics. Although the predicted broadband noise levels at higher frequencies fall below the experimental data due to the fundamental shortcomings of the utilized formulations, the analysis offers a detailed physical understanding of the fan noise generation processes.

• 한국초등과학교육학회지:초등과학교육
• /
• 제34권1호
• /
• pp.58-71
• /
• 2015

Ability of understanding students' ideas and thinking is critical to teachers' professional growth. In this study, 'pedagogical reasoning' was conceptualized as teachers' reasoning ability of students' misconceptions and possible causes of misconceptions when they hear and observe students' science discourses. To investigate elementary pre-service teachers' pedagogical reasoning levels, children's science discourses on light reflection and electric circuit were video recorded and 43 pre-service elementary teachers were asked to identify children's misconceptions and possible causes of misconceptions after watching the video clips. In conclusion, pedagogical reasoning levels of pre-service elementary teachers were not high enough, showing significant difference in light reflection and electric circuit. Possible explanations of this difference and educational implications were discussed.

• 한국CDE학회논문집
• /
• 제17권4호
• /
• pp.234-245
• /
• 2012

This paper proposes a multi-level product modeling framework for long-term lifecycle products. The framework can help engineers to define product models and relate them to physical instances. The framework is defined in three levels; data, design model, modeling language. The data level represents real-world products, The model level describes design models of real-world products. The modeling language level defines concepts and relationships to describe product design models. The concepts and relationships in the modeling language level enable engineers to express the semantics of product models in an engineering-friendly way. The interactions between these three levels are explained to show how the framework can manage long-term lifecycle product information. A prototype system is provided for further understanding of the framework.

• 아동학회지
• /
• 제34권4호
• /
• pp.125-141
• /
• 2013

The following study to enhance children's creativity in the context of diverse cultures and ethnic groups, and utilizes various programs from different countries aimed at 5 year old children with the Nuri framework. The study also seeks to measure pre and post play behaviors, creativity levels, and thinking capabilities of the children, then compare these results with those from a control group. Analysis of the results indicates that children who experienced programs from various countries through a multicultural approach had much higher levels of fluency, adaptability, originality, and imaginative capabilities than children who had not experienced such programs. Among the children's creative play behaviors, intrinsic motive-magination, sensitivity-curiosity, longetivity-concentration, various forms of interest-challenge, and leadership-independence were all found to be significantly higher.

• Asia pacific journal of information systems
• /
• 제13권2호
• /
• pp.1-21
• /
• 2003

Although the internet community(IC) has been recognized as an increasingly important for better understanding and relationships with customers, few evidence has been accumulated what factors influence IC success. This study posits the characteristics and individual characteristics as key determinants of IC success, and related hypotheses were tested using 230 data. Using user loyalty as a surrogate of IC success, this study found that the three key characteristics of IC-focus, interactivity, and cohesion levels-significantly influence the community user's loyalty. In addition, individual characteristics including personal value propositions(e.g, challenge/ambitious value, economic/rational value) and absorption tendency(e.g., flow level) affect their loyalty levels. This study also found that the determinents of IC user's loyalty defer with different types of community such as entertainment, relationships, and information/opinion sharing communities. These findings are hopefully helpful for the successful and contingent management of IC buildings and operations.

• Biomolecules & Therapeutics
• /
• 제26권1호
• /
• pp.69-80
• /
• 2018

Cancer cells reprogram cellular metabolism to support the malignant features of tumors, such as rapid growth and proliferation. The cancer promoting effects of metabolic reprogramming are found in many aspects: generating additional energy, providing more anabolic molecules for biosynthesis, and rebalancing cellular redox states in cancer cells. Metabolic pathways are considered the pipelines to supply metabolic cofactors of epigenetic modifiers. In this regard, cancer metabolism, whereby cellular metabolite levels are greatly altered compared to normal levels, is closely associated with cancer epigenetics, which is implicated in many stages of tumorigenesis. In this review, we provide an overview of cancer metabolism and its involvement in epigenetic modifications and suggest that the metabolic adaptation leading to epigenetic changes in cancer cells is an important non-genetic factor for tumor progression, which cooperates with genetic causes. Understanding the interaction of metabolic reprogramming with epigenetics in cancers may help to develop novel or highly improved therapeutic strategies that target cancer metabolism.

• 아동학회지
• /
• 제25권1호
• /
• pp.13-29
• /
• 2004

In this study of strategies used by young children in solving rectangular covering tasks before they have been taught area measurement, 75 5-, 6-, and 7-year-old children were asked to solve 3 rectangular covering tasks with a moveable unit. Three different sized units (4 cm., 2 cm., and 1 cm. cardboard squares) were provided and the children were asked to work out how many would be needed to cover a drawn rectangle. The resulting 5 developmental levels include incomplete covering, incomplete arrangement, complete covering, estimating, and measuring. Children using more advanced strategies were able to find correct number of units. While the tendency among older children was to use more advanced strategies, even 5-year-olds had an intuitive understanding of rectangular area measurement.

• Journal of Plant Biotechnology
• /
• 제33권2호
• /
• pp.139-145
• /
• 2006

The present study is the first report of molecular variations in different accessions of Rauvolfia tetraphylla L.f, a medicinally important plant collected from seven locations of Andhra Pradesh, India. Molecular analysis was carried out using RAPD markers. Out of the 40 primers screened from OPA and OPC Kts, a total of 205 scorable polymorphic markers out of 397 total markers were generated. Polymorphism of 51.6% was found with 3 unique markers. Levels of genetic diversity within accessions i.e., the genetic distance ranged from 0.816-0.932. Cluster analysis based on Dice coefficient showed two major groups indicating that mostly in cross-pollinated plants, high levels of differentiation among accessions exists independent of geographical distance. Hence the results of the present study can be seen as a starting point for future researches on the population and evolutionary genetics of this species. Understanding such variation would also facilitate their use in various conservational management practices, rootstock breeding and hybridisation programmes.