• Journal of Powder Materials
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• v.9 no.4
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• pp.218-226
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• 2002

The purpose of the present study is to investigate the influence of thermal debinding and sintering conditions on the sintering behavior and mechanical properties of PIMed 316L stainless steel. The water atomized powders were mixed with multi-component wax-base binder system, injection molded into flat tensile specimens. Binder was removed by solvent immersion method followed by thermal debinding, which was carried out in air and hydrogen atmospheres. Sintering was done in hydrogen for 1 hour at temperatures ranging from 1000℃ to 1350℃ The weight loss, residual carbon and oxygen contents were monitored at each stage of debinding and sintering processes. Tensile properties of the sintered specimen varied depending on the densification and the characteristics of the grain boundaries, which includes the pore morphology and residual oxides at the boundaries. The sinter density, tensile strength (UTS), and elongation to fracture of the optimized specimen were 95%, 540 MPa, and 53%, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.40-47
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• 1994

The objective of this research was to examine the effect of ammonium thiosulfate(ATS) on urease activity and on biological and chemical properties of flooded paddy soil especially having high organic matter content by comparing with the effect of sodium thiosulfate(STS). The results obtained are summarized as follows. 1. The hydrolysis of urea was inhibited at 3 and 5 days after treatment of thiosulfate(ATS and STS) +glucose and thiosulfate only, respectively. The inhibitory effect of ATS on urea hydrolysis was slightly lower than that of STS in glusoce-added soils, but when the glucose was not added, the effects of ATS and STS were not different significantly. 2. The soil pH and Eh was lowered by 0.3~0.5 units and 30~120 mV, respectively, when incubated flooded soil with ATS and glucose at $25^{\circ}C$. 3. Soil respiration rate in/flooded soil was increased by 10~70% with the treatment of ATS during the 20 day experimental period. 4. The contents of acetic and butyric acid in thiosulfate treatment soil was below $10{\mu}g/g$, which was lower than that($220.3{\mu}g/g$) of critical growth inhibition of rice.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.74-87
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• 2003

A model of STS (Science-Technology-Society) creativity education program for the gifted and talented children has been developed, based on GENEPLORE thinking process and Knowledge development theory. The GENEPLORE creative thinking process, developed by Finke et al. (1990, 1992), has two phases such as generative phase and exploratory phase. And The knowledge development theories of Piaget (1977) and Gallagher(1981) assume that knowledge-bases are developed on the basis of empirical as well as reflective abstraction, which could imply that knowledge-bases are crucial in creative thinking process. The creativity education model for the gifted and talented of the present study attempted to integrate 'the individual, creative thinking process, and social/scientific technology' by employing topics of the science-technology-society such as computer, network, biotech, robot, e-business, e-education, e-health, nanotech and entertainment and the structure and contents of the program are proposed

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1001-1009
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• 2016

This study was conducted to investigate the relationship between quality factors and palatability of modified Doenjang and traditional Doenjang. Fourteen types of Doenjang, including three modified Doenjang and 11 traditional Doenjang samples, were analyzed to evaluate their physicochemical and sensorial properties. There were differences in e-tongue, which indicates overall acceptability. Water contents, minerals, total sugar contents, salt contents, pH, titratable acidity, and free amino acids of Doenjang did not show significant differences. From the correlation and regression analysis, palatability was closely related to the e-tongue sensor such as $X_1$ (sourness), $X_3$ (saltiness), and $X_4$ (umami) to -0.772, -0.642, and 0.678, respectively. The regression equation for sensorial palatability (Y) was Y=$45.356-0.008X_1-0.010X_3$ with a coefficient of 0.882.

• Journal of The Korean Association For Science Education
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• v.20 no.2
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• pp.274-287
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• 2000

This study was performed the analysis of four kinds of common science textbooks based on the 6th curriculum. Particularly, inquiry activity part was analyzed by the three dimension framework which consists of inquiry content dimension, inquiry process dimension and inquiry context dimension. In the analysis of the inquiry content dimension of inquiry activities, the contents revised by 6th curriculum of common science textbook was accomplished through various inquiry activities. The number of inquiry activity in four textbooks was similar as about 16. The For the analysis of inquiry process dimension, 'interpreting data and formulating generalizations' category (39.1%) was most emphasized and the categories of 'observation and measuring'(30.8%), and 'building, testing and revising the theoretical model' (16.5 %), 'seeing a problem and seeking ways to solve it' (13.5%) follow in order. As for the analysis of the inquiry context dimension, the proportion of STS related contents in inquiry activities was only 18%. So, we propose that STS related contents would increase the proportion for the following textbook.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.9-20
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• 2014

Making good predictions about the outcome of one's actions would seem to be essential in the context of social interaction and decision-making. This paper proposes a computational model for learning articulated motion patterns for action recognition, which mimics biological-inspired visual perception processing of human brain. Developed model of cortical architecture for the unsupervised learning of motion sequence, builds upon neurophysiological knowledge about the cortical sites such as IT, MT, STS and specific neuronal representation which contribute to articulated motion perception. Experiments show how the model automatically selects significant motion patterns as well as meaningful static snapshot categories from continuous video input. Such key poses correspond to articulated postures which are utilized in probing the trained network to impose implied motion perception from static views. We also present how sequence selective representations are learned in STS by fusing snapshot and motion input and how learned feedback connections enable making predictions about future input sequence. Network simulations demonstrate the computational capacity of the proposed model for motion recognition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.809-818
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• 2022

The number of ships using liquefied natural gas (LNG) as fuel is increasing to respond to the International Maritime Organization's (IMO) air pollutant emission regulations. At the same time, the need to expand LNG bunkering infrastructure for stable fuel supply and demand for ships is emerging. LNG bunkering is carried out in three ways: truck to ship (TTS), pipe to ship (PTS), and ship to ship (STS). In foreign countries, all three methods are being carried out, but in Korea, LNG bunkering is carried out only with the TTS method owing to the lack of infrastructure. LNG bunkering is a high-risk operation. For safe bunkering operations, the competence of the workers is extremely important, and a professional training course is required to strengthen the competence. This study was conducted to design training contents for LNG bunkering workers for fostering LNG bunkering experts and performing safe and systematic bunkering work. To this end, the current status of LNG-fueled ships and bunkering was identified, and related domestic and abroad educational contents were analyzed. In addition, opinions on the importance of educational contents were collected through expert questionnaires. Consequently, we designed training contents suitable for various training targets and divided them into basic and advanced training courses, with a duration of 4 days, and proposed. Based on the designed training contents, if additional research is conducted by sufficiently reflecting Korea's bunkering environment, it will be of great help to improve the competence of LNG bunkering workers and to foster human resources.

• Journal of Korean Elementary Science Education
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• v.31 no.2
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• pp.164-176
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• 2012

The purpose of this study was to find some suggestions for reorganization of contents about particle concept of matter in Korean science curriculum. For the purpose of this study, authors analyzed features of Korean science curriculum and compared science curricula of Korea, USA, UK, Japan and Finland. From the result of this study, authors find some features and important suggestions about reorganization of contents about particle in science curriculum. First, the sequence of contents about particle concepts in 2009 Revised National Curriculum was similar to that in the 6th National Science Curriculum. And the feature of 2009 Revised National Curriculum showed the articulation of contents about particle concept. If contents about particle concept is increased in elementary science curriculum, the total articulation would be increased. Second, the presenting sequence of atomic structure-first and laws about atom-later should be changed to laws about atomic-first and atomic structure-later. This presenting sequence is grounded by science curricula of other countries, history of science and developmental psychology. And science curriculum of Korea was required specific extended concept statement like science curricula of USA or UK. Also, Korean science curriculum could benchmark Finnish science curriculum if we want to develop some integrated learning activities such as those in STS or STEAM program.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.331-339
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• 2001

Zero to tension fatigue tests and strain controlled fatigue tests were carried out to find how initial strain induced martensite, ${\alpha}^{\prime}$ affects low and high cycle fatigue behavior and fatigue crack growth mechanisms. Microscopic study and phase analysis were carried out with TEM, SEM, EDAX, Optical Microscope, Ferriscope, and X-ray diffractometry. The amount of Initial ${\alpha}^{\prime}$ was controlled from 0% to 33% by controlling the temperatures for cold working and heat treatment. Lower contents of initial ${\alpha}^{\prime}$ showed higher fatigue resistance in low cycle fatigue but lower fatigue resistance in high cycle fatigue because it is ascribed to the more transformation of ${\alpha}^{\prime}$ martensite during low cycle fatigue and higher ductility. In high cycle fatigue, fatigue life is attributed to the strength and phase transformation of austenite into ${\alpha}^{\prime}$ during fatigue was negligible. ${\gamma}$ boundary, ${\gamma}/twin$ boundary, and ${\gamma}/{\alpha}^{\prime}$ boundary were found to be the preferred site of fatigue crack initiation.

• Journal of Digital Contents Society
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• v.5 no.2
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• pp.157-162
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• 2004

A development of PP/ST is essential in CC environment. And, the KOREA is expected that PP/STs demand increases explosively by joining to CCRA hereafter. Specially, PP/ST development experience of the KOREA is lacking. So, development of security environment(assume, threat, policy) and security objective contents refer only PP/ST Guide(ISO/IEC PDTR 15446) are very difficult. In this paper, we propose a web service based common security environment and security objective repository model that make developers can run PP/ST creation to be simple. Through proposed model, developers who development experience is lacking are expected to achieve PP/ST development to be simple.