• Journal of Educational Research in Mathematics
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• v.19 no.4
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• pp.545-564
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• 2009

TPACK (Technological Pedagogical Content Knowledge) adds the technological knowledge to PCK (Shulman 1986), completing the combination of three kinds of knowledge, i.e. teacher's content knowledge (CK), pedagogical knowledge (PK), and technological knowledge (TK). In this study, I seek to design methodological ways to improve TPACK for preservice mathematics teachers by developing and analyzing team project-based classes with technology in a class of the first semester 2009 in a teacher's college in Seoul, South Korea. The goal of the team project is to design classes to teach mathematics with technology by selecting technology tools suitable for specific mathematical concepts or mathematics sections. In the early stage of the class in the college, the confidence levels among the preservice mathematics teachers were relatively low but increased in the final stage their mathematics teaching efficacy up to from 3.88 to 4.50. Also, the pre service mathematics teachers answered the team project was helpful or very helpful in developing TPACK; this result proves that lectures with technology which based on team project are excellent tools for the teacher to design classes with technology confidently. Considering the teacher's TPACK is one of the abilities to achieve the goals required in the information technology era, the preservice mathematics teachers are asked to plan and develop the lectures with technology, rather than just taught to know how to use technology tools or adapt to specific cases. Finally, we see that national-wide discussion and research are necessary to prepare customized standards and implementable plans for TPACK in South Korea.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.4-27
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• 2010

In this article, concepts, types, and aspects of geological heritage with increasing interests as utilization as tourist attractions domestically and internationally are introduced, and the characteristics of the interpretive facilities for geological heritages in western Australia, one of the most famous geotourism areas, are considered. Based on this, the potential geotourism for the Korean Cretaceous geological heritages including dinosaur fossil sites is discussed in diverse aspects including academic values, academic and tourism infrastructures, characteristics of geotourists, systematic devices for conservation of geological heritage, economic value, and sustainability as tourist attractions. Although the Korean Cretaceous geosites are not quite competent in their scale or diversity when compared to world-class geosites, convenient access, world-class unique geographical characteristics of each geosites, and relatively cheaper travelling expenses seems to be able to give the geotourism of the South Korean Cretaceous geosites a competitive edge, attractive for international and domestic tourists seeking unique experience of 'Age of dinosaurs' for short periods with easy access from metropolitan areas and low costs. Likewise, the development of geotourism for the Korean Cretaceous geosites can revitalize the geotourism industry in South Korea, contributing to the growth in job opportunities, including students majoring in geological sciences at University.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.3
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• pp.297-304
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• 2012

For the assessment of the performance of a wind-turbine blade, a simulated loading test may be required. In this study, the blade behavior was investigated through numerical analysis using a dual-axis loading test, closely simulating the real operation conditions. The blade structure for the 100-kW-class wind-turbine system was modeled using the finite element (FE) program ANSYS. The failure criteria and buckling analysis under dual-axis loading were examined. The failure analysis, including fiber failure and inter-fiber failure, was performed with Puck's failure criterion. As the dual-axis load ratio increases, the relatively increased stress occurs at the trailing edge and skin surface 3300-3600 mm away from the root. Furthermore, it is revealed that increasing the dual-axis load ratio makes the location that is weakest against buckling move toward the root part. Thus, it is seen that the dual-axis load test may be an essential requirement for the verification of blade performance.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.89-104
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• 2011

This study was carried out to the development of ecological planting model to make up of coastal windbreak forest on the Suncheon-bay in Sucheon-si, Korea. Make up of coastal windbreak forest in this site was needed for appropriate bioresource, biodiversity and ecological structure, and for conservation of the eco-tour resource and protection of human life and property by the unforeseen disaster from the coast. Based on the plant-social principle, the planting model of windbreak forest was developed to facilitate growth of trees, considering planting locations. The ecological planting model for the coastal windbreak was composed of warm temperate evergreen and windbreak forest which is spreading around the inland area in Korea. The horizontal forest style was composed of forest edge community and inner forest community, and the vertical forest style was composed of upper, middle, low and ground planting class. The target of the present model was quasi-natural forest, and the species of tree were selected based on the adaptability to surroundings depending on a goal to create a forest and forest style. To achieve both functions of wind break forest and visual effect in short period of time, small trees and seedlings were planted with high-density of 40,000/ha in an expectation of easy natural maintenance in the future. The significance of the present study is a suggestion for a guideline to create ecological coastal windbreak forest in the Suncheon-bay in which the harmony of human life and the ecological conservation is of great importance. Also, the ecological coastal windbreak forest model should be developed further through the long term monitoring after construction of forest.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.7
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• pp.718-728
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• 2013

Analysis of scenarios of transportation oil and gas which produced in the Arctic and others cold seas shows that in the near-term there will be a significant increase of tonnage of tankers for oil and gas and number of ships which should be exploited in difficult ice conditions. For the construction of ice-resistant structures (IRS) intended for production of oil and gas and transportation of these products at ice-class vessels, calculating the load from ice to board the ship and on surface of supports of the platforms are the actuality and urgent tasks. These tasks have one basis in both cases: at beginning of the contact occurs fracture of edge of ice, then occurs compressing of rubble shattered of ice, then they extruding from contact area, after this next layer of ice begin to destruct. At calculating the strength of plating and elements construct of vessels, icebreakers and ice-resistant platforms the specific energy of mechanical destruction ice ${\epsilon}_{cr}$ is an important parameter. For the whole period of study of physical and mechanical characteristics of sea ice have been not many experimental studies various researchers to obtain numerical values of this energetic characteristic of the strength of ice by a method called Ball Drop Test. This study shows that the destruction of the ice from dynamic loading in zone of contact occurs in several cycles, and the ice destructed with a minimum numerical values of ${\epsilon}_{cr}$. The author offer this energy characteristic to take as a base value for the calculation of ice load on ships and offshore structures.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2555-2564
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• 2000

In this paper, a new unsupervised image segmentation algorithm is proposed. To model the contextual information presented in images, the characteristics of the Markov random fields (MRF) are utilized. Textured images are modeled as realizations of the stationary Gaussian MRF on a two-dimensional square lattice using the conditional autoregressive (CAR) equations with a second-order noncausal neighborhood. To detect boundaries, hypothesis tests over two masked areas are performed. Under the hypothesis, masked areas are assumed to belong to the same class of textures and CAR equation parameters are estimated in a minimum-mean-square-error (MMSE) sense. If the hypothesis is rejected, a measure of dissimilarity between two areas is accumulated on the rejected area. This approach produces potential edge maps. Using these maps, boundary detection can be performed, which resulting no micro edges. The performance of the proposed algorithm is evaluated by some experiments using real images as weB as synthetic ones. The experiments demonstrate that the proposed algorithm can produce satisfactorY segmentation without any a priori information.

• Korean Journal of Environment and Ecology
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• v.5 no.1
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• pp.91-103
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• 1991

Use impacts on environmental deteriorations of trail and campsite were studied in Chirisan National Park in 1991. The entire width, bare width and maximum depth of trail as the trail condition were significantly greater on the more heavily used trail. Trail conditions, especially altitude, entire width and maximum depth of deteriorated points which were surveyed at the total of 82 were significantly different from those of non-deteriorated points. On the ridge trail, the damaged are more severe than Class 4 reaches about 34,000$m^2$ and use impacts on campsite and deterioration were also accelerated. The dominant trees of the upper layer in trail edge vegetation are changed from Carpinus tschonoskii to Quercus serrata, Carpinus laxiflora and to Quercus mongolica, Carpins laxiflora at Hwaeomsa trail, and from Quercus serrata to Quercus mongolica at Piagol trail. Also Lespedoza maximowiczii, Symplocos chinensis, Deutzia prunifolia, Weigela Subsessilis appear as the dominant lower species at Hwaeomsa trail, L. maximowiczii, S. chinensis, Stephanandra incisa, Rhododendron schlippenbachii for Piagol trail.

• The Research Journal of the Costume Culture
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• v.16 no.6
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• pp.1019-1034
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• 2008

The purpose of this study is to grasp creation background and social position of courtesan which is treated in social and cultural context and its effect on fashion and research representative courtesans from ancient hetaera to the 19th century and their costume characteristics. Its another purpose is to analyze the costume of Violetta, who is a heroine of opera and its costume characteristic as a courtesan. Most Courtesan clothing were made from bright color, silk and lace which were light, or transparent materials. Using silk and cashmere which were the symbols of class, she took the cutting edge fashion and struggled to break the social barriers. The clothing which the Courtesan wore always became a gossip among people and popular to the designers who could show their creativities because the Courtesan boldly wore the cloth like movie actresses or stars. The Courtesan who led the fashion not only showed the fashion as a simple expression of the beauty but also as a socio-cultural phenomenon which reflected their social awareness with arts, and changed according to the situations of the time and people. Violetta's party dress which was shown in the first and third acts of showed the shoulders and chest because of the deep and wide cut decollete, the waist was tightened with a corset as much as possible, and the opulent hips were inflated by the crinoline so when they walked it was swaying. Also it was decorated with splendid materials such as silk and lace, and sparkling jewels, fans, and neckless and even in case of the general clothing in the second act, it was decorated with braids and lace, frills and ribbons. In the third act, the weakness of the sick woman who was closing her life as the splendid Courtesan was emphasized by using colors of white and light purple and thin transparent materials.

• Journal of Engineering Education Research
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• v.3 no.2
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• pp.84-92
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• 2000

U.S. Congress established the Malcolm Baldrige National Quality Award (MBNQA) program in 1987 to recognize U.S. organizations for their achievements in quality and business performance and to raise awareness about the importance of quality and performance excellence as a competitive edge. The Baldrige Award was envisioned as a standard of excellence that would help U.S. organizations achieve world-class quality. Recently the U.S, Congress approved legislation that made education and health care organizations eligible to participate in the Award Program. These criteria are applied to evaluate two academic departments (Computer Science & Industrial Systems and Electrical Engineering) at Yonsei University. It was an informal evaluation performed by the undergraduate students who took quality Engineering course. Evaluated total scores turn out to be 522.5 and 548.5 for both, respectively. According to the MBNQA diagnosis, this level of score represents that there are some areas or work units which need to be improved. We hightlight them so that they can be used as feedback information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8B
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• pp.514-524
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• 2005

In optical burst switching(OBS) networks, the ingress edge router assembles packets in the same class queue into the appropriate size of burst. A burst control packet(BCP) is generated for channel reservation of corresponding data burst and sent earlier than the corresponding data burst with an offset time. Offset time is determined considering the number of hops from source to destination and the required quality of service(QoS). After offset time, the burst data is passed through tile pre-configured optical switches without any O/E/O conversion. But a failure in OBS networks may lead to the loss of bursts until the ingress nodes receive the failure indication signal. This results in a significant degradation in QoS. Therefore, in this paper, we propose a fault-tolerant node architecture based on sub-carrier multiplexing to reduce the effects of failure in OBS networks. The Performance of the proposed fault-tolerant node architecture exhibits considerable improvement as compared with the previous ones.