• Journal of the Korean earth science society
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• v.22 no.5
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• pp.360-376
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• 2001

This qualitative research investigated in-service science teachers' perceptions about cooperative learning and their perceived barriers in implementing cooperative learning in their classrooms. The underlying premise for cooperative learning is founded in constructivist epistemology. Cooperative learning (CL) is presented as an alternative frame to the current educational system which emphasizes content memorization and individual student performance through competition. An in-depth interview was conducted with 18 in-service science teachers who enrolled in the first-class teacher certification program during 2001 summer vacation. These secondary school teachers's interview data were analyzed and categorized into three areas: teachers' definition of cooperative learning, issues with implementing cooperative learning in classrooms, and teachers' and students' responses towards cooperative learning. Each of these areas are further subdivided into 10 themes: teachers' perceived meaning of cooperative learning, the importance of talk in learning, when to use cooperative learning, how to end a cooperative class, how to group students for cooperative learning, obstacles to implementing cooperative learning, students' reactions to cooperative learning, teachers' reasons for choosing (not choosing) student-centered approaches to learning/teaching, characteristics of teachers who use cooperative learning methods, and teachers' reasons for resisting cooperative learning. Detailed descriptions of the teachers' responses and discussion on each category are provided. For the development and implementation of CL in more classrooms, there should be changes and supports in the following five areas: (1) teachers have to examine their pedagogical beliefs toward constructivist perspectives, (2) teacher (re)education programs have to provide teachers with cooperative learning opportunities in methods courses, (3) students' understanding of their changed roles (4) supports in light of curriculum materials and instructional resources, (5) supports in terms of facilities and administrators. It's important to remember that cooperative learning is not a panacea for all instructional problems. It's only one way of teaching and learning, useful for specific kinds of teaching goals and especially relevant for classrooms with a wide mix of student academic skills. Suggestions for further research are also provided.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.108-116
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• 2006

Purpose : High-resolution spiral-scan imaging is performed at 3 Tesla MRI system. Since the gradient waveforms for the spiral-scan imaging have lower slopes than those for the Echo Planar Imaging (EPI), they can be implemented with the gradient systems having lower slew rates. The spiral-scan imaging also involves less eddy currents due to the smooth gradient waveforms. The spiral-scan imaging method does not suffer from high specific absorption rate (SAR), which is one of the main obstacles in high field imaging for rf echo-based fast imaging methods such as fast spin echo techniques. Thus, the spiral-scan imaging has a great potential for the high-speed imaging in high magnetic fields. In this paper, we presented various high-resolution images obtained by the spiral-scan methods at 3T MRI system for various applications. Materials and Methods : High-resolution spiral-scan imaging technique is implemented at 3T whole body MRI system. An efficient and fast higher-order shimming technique is developed to reduce the inhomogeneity, and the single-shot and interleaved spiral-scan imaging methods are developed. Spin-echo and gradient-echo based spiral-scan imaging methods are implemented, and image contrast and signal-tonoise ratio are controlled by the echo time, repetition time, and the rf flip angles. Results : Spiral-scan images having various resolutions are obtained at 3T MRI system. Since the absolute magnitude of the inhomogeneity is increasing in higher magnetic fields, higher order shimming to reduce the inhomogeneity becomes more important. A fast shimming technique in which axial, sagittal, and coronal sectional inhomogeneity maps are obtained in one scan is developed, and the shimming method based on the analysis of spherical harmonics of the inhomogeneity map is applied. For phantom and invivo head imaging, image matrix size of about $100{\times}100$ is obtained by a single-shot spiral-scan imaging, and a matrix size of $256{\times}256$ is obtained by the interleaved spiral-scan imaging with the number of interleaves of from 6 to 12. Conclusion : High field imaging becomes increasingly important due to the improved signal-to-noise ratio, larger spectral separation, and the higher BOLD-based contrast. The increasing SAR is, however, a limiting factor in high field imaging. Since the spiral-scan imaging has a very low SAR, and lower hardware requirements for the implementation of the technique compared to EPI, it is suitable for a rapid imaging in high fields. In this paper, the spiral-scan imaging with various resolutions from $100{\times}100$ to $256{\times}256$ by controlling the number of interleaves are developed for the high-speed imaging in high magnetic fields.

• Journal of Science Education
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• v.34 no.2
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• pp.405-420
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• 2010

The purpose of this study was to contrive the specific teaching plans based on the frame of 2007 revised science curriculum for applying open-inquiry lesson in real education situation and to research the effects of open-inquiry lesson on the student's science-related attitude, science process skill, and to investigate instructing teachers' cognition about open-inquiry. For this study, two fifth grade classes were chosen, one class was the experimental group, who were taught by open-inquiry based lesson, and another was the comparative group, who were taught by traditional method based lesson. The findings of this study were as follows: After open-inquiry lesson, the experimental group students came to enjoy open-inquiry learning and had the positive thought about it. After open-inquiry lesson, the experimental group marked higher mean score than the comparative group in science-related attitude's field but didn't showed the meaningful difference. On the other hand, in science process skill's field, the experimental group showed the significant higher improvement than the comparative one, especially in the subordinate area of basic science process skill. Finally, teachers who instructed students open-inquiry lesson thought open-inquiry lesson is the self-directed problem solving learning which raise the student's science process skill and interest. And the teachers thought the obstacles to instruct open-inquiry lesson are the lack of the student's cognition about open-inquiry and the insufficient circumstance for open-inquiry lesson. Therefore the teachers argued that the prerequisite for settling open-inquiry lesson successfully is to develope open-inquiry lesson curricula and teaching materials.

• Journal of the Korean Society of Food Culture
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• v.16 no.2
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• pp.81-88
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• 2001

This study is to investigate attitude by college students toward transformation of traditional food into fast food style. Data were collected from a convenient sample of 340 students who were enrolled in colleges in Busan metropolitan area. Bivariate analyses with sociodemographic characteristics were made on attitude including evaluation on effects of western fast food taking on eating practice, comparison of willingness to take western-brand fast food with traditional food in fast food style, evaluation of domestic-brand fast food, need and probability of success of operation of fast food restaurant serving only traditional food, list of kinds of traditional food could be in fast food, perceived obstacles to develop traditional food in fast food style and intention to utilize fast food restaurant serving only traditional food if available.

• The Journal of the Korea Contents Association
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• v.13 no.3
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• pp.65-75
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• 2013

Movie captured audience's whole sense organs to the screen which is made up of visual story-telling decorated by color, sound, and smell. The audience rediscovered native emotions(pleasure, fear, terror) suppressed and left in the compressed world of space and time, that is to say a movie world separated from the real world, by being immersed in the movie story. This study revealed audience's feelings of pleasure and fear by analyzing the movie . First of all, the pleasure would be discussed in terms of Nietzsche's "the will to power." Nietzsche defined something to breathe, move, and will as being alive, and he insisted that its power to life is 'the will to power.' Human beings wish to have power and want to increase it: pleasure, the real motivation of human behaviors and phenomena. The movie well revealed the pleasure by showing nonperson's challenge and victory against social rulers. Second, the fear and terror of the audience will be discussed in terms of in Lacan's psychoanalysis. Lacan extended Freud's id, ego, and superego into the worlds of reality, imagine, and symbol, and suggested a father in symbol world among those worlds. He suggested as a basic and connecting instrument of the socialization just like Signifi$\acute{e}$ and Signifiant, Saussure' basic linguistic structure in "Cours de lingustique g$\acute{e}$n$\acute{e}$rale"(1916). Because father is the symbol and the metaphor of law, the absence of him and resistance against him means obstacles of social stabilization. Finally this paper will also discuss that the fear from the absence of law and the pleasure provoked by self-preserving instincts, that is to say natural feelings, are connected to values of progressivism and conservatism.

• Journal of KIISE:Information Networking
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• v.35 no.2
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• pp.99-111
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• 2008

In recent years, the needs for WLANs(Wireless Local Area Networks) technology which can access to Internet anywhere have been dramatically increased particularly in SOHO(Small Office Home Office) and Hot Spot. However, unlike wired networks, there are some unique characteristics of wireless networks. These characteristics include the burst packet losses due to unreliable wireless channel. Note that burst packet losses, which occur when the distance between the wireless station and the AP(Access Point) increase or when obstacles move temporarily between the station and AP, are very frequent in 802.11 networks. Conversely, due to burst packet losses, the performance of 802.11 networks are not always as sufficient as the current application require, particularly when they use TCP at the transport layer. The high packet loss rate over wireless links can trigger unnecessary execution of TCP congestion control algorithm, resulting in performance degradation. In order to overcome the limitations of WLANs environment, MAC-layer LDA(Loss Differentiation Algorithm)has been proposed. MAC-layer LDA prevents TCP's timeout by increasing CRD(Consecutive Retry Duration) higher than burst packet loss duration. However, in the wireless channel with high packet loss rate, MAC-layer LDA does not work well because of two reason: (a) If the CRD is lower than burst packet loss duration due to the limited increase of retry limit, end-to-end performance is degraded. (b) energy of mobile device and bandwidth utilization in the wireless link are wasted unnecessarily by Reducing the drainage speed of the network buffer due to the increase of CRD. In this paper, we propose a new retransmission module based on Cross-layer approach, called BLD(Burst Loss Detection) module, to solve the limitation of previous link layer retransmission schemes. BLD module's algorithm is retransmission mechanism at IEEE 802.11 networks and performs retransmission based on the interaction between retransmission mechanisms of the MAC layer and TCP. From the simulation by using ns-2(Network Simulator), we could see more improved TCP throughput and energy efficiency with the proposed scheme than previous mechanisms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.508-516
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• 2010

An autonomous and automatic home mess-cleanup robot is newly developed in this paper. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot (McBot) to completely overcome this problem. The robot needs the capability for agile navigation and a novel manipulation system for mess-cleanup. The autonomous navigational system has to be controlled for the full scanning of the living room and for the precise tracking of the desired path. It must be also be able to recognize the absolute position and orientation of itself and to distinguish the messed object that is to be cleaned up from obstacles that should merely be avoided. The manipulator, which is not needed in a vacuum-cleaning robot, has the functions of distinguishing the large trash that is to be cleaned from the messed objects that are to be arranged. It needs to use its discretion with regard to the form of the messed objects and to properly carry these objects to the destination. In particular, in this paper, we describe our approach for achieving accurate localization using RFID for home mess-cleanup robots. Finally, the effectiveness of the developed McBot is confirmed through live tests of the mess-cleanup task.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.49-67
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• 2015

Recently, emerging the notion of big data and social media has led us to enter data's big bang. Social networking services are widely used by people around the world, and they have become a part of major communication tools for all ages. Over the last decade, as online social networking sites become increasingly popular, companies tend to focus on advanced social media analysis for their marketing strategies. In addition to social media analysis, companies are mainly concerned about propagating of negative opinions on social networking sites such as Facebook and Twitter, as well as e-commerce sites. The effect of online word of mouth (WOM) such as product rating, product review, and product recommendations is very influential, and negative opinions have significant impact on product sales. This trend has increased researchers' attention to a natural language processing, such as a sentiment analysis. A sentiment analysis, also refers to as an opinion mining, is a process of identifying the polarity of subjective information and has been applied to various research and practical fields. However, there are obstacles lies when Korean language (Hangul) is used in a natural language processing because it is an agglutinative language with rich morphology pose problems. Therefore, there is a lack of Korean natural language processing resources such as a sentiment lexicon, and this has resulted in significant limitations for researchers and practitioners who are considering sentiment analysis. Our study builds a Korean sentiment lexicon with collective intelligence, and provides API (Application Programming Interface) service to open and share a sentiment lexicon data with the public (www.openhangul.com). For the pre-processing, we have created a Korean lexicon database with over 517,178 words and classified them into sentiment and non-sentiment words. In order to classify them, we first identified stop words which often quite likely to play a negative role in sentiment analysis and excluded them from our sentiment scoring. In general, sentiment words are nouns, adjectives, verbs, adverbs as they have sentimental expressions such as positive, neutral, and negative. On the other hands, non-sentiment words are interjection, determiner, numeral, postposition, etc. as they generally have no sentimental expressions. To build a reliable sentiment lexicon, we have adopted a concept of collective intelligence as a model for crowdsourcing. In addition, a concept of folksonomy has been implemented in the process of taxonomy to help collective intelligence. In order to make up for an inherent weakness of folksonomy, we have adopted a majority rule by building a voting system. Participants, as voters were offered three voting options to choose from positivity, negativity, and neutrality, and the voting have been conducted on one of the largest social networking sites for college students in Korea. More than 35,000 votes have been made by college students in Korea, and we keep this voting system open by maintaining the project as a perpetual study. Besides, any change in the sentiment score of words can be an important observation because it enables us to keep track of temporal changes in Korean language as a natural language. Lastly, our study offers a RESTful, JSON based API service through a web platform to make easier support for users such as researchers, companies, and developers. Finally, our study makes important contributions to both research and practice. In terms of research, our Korean sentiment lexicon plays an important role as a resource for Korean natural language processing. In terms of practice, practitioners such as managers and marketers can implement sentiment analysis effectively by using Korean sentiment lexicon we built. Moreover, our study sheds new light on the value of folksonomy by combining collective intelligence, and we also expect to give a new direction and a new start to the development of Korean natural language processing.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.803-812
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• 2014

This study assesses the strategy and performance of Eco-industrial Park (EIP) initiative implemented by Korea Industrial Complex Corporation (KICOX) with the support of Ministry of Trade, Industry and Energy (MOTIE), Korea since 2005 to 2013 and recommends future directions. After the concept of EIP based on industrial symbiosis (IS) is introduced, the background and implementation procedure of the EIP initiative are described. Then, economic and environmental achievement was assessed. During the project periods (2005-2013), 449 industrial symbiosis project were explored, among which 296 projects have been implemented. Among (Of these 296 projects,) them, 244 projects have been completed in which 118 projects have been commercialized which shows 48% commercialization rate of the completed projects. Through these commercialized projects, around 311.1 billion won/year of economic benefits and reduction of waste by-products of 828,113 tons/year, wastewater of 215,517 tons/year, reduction in energy consumption of 250,475 toe/year and GHG emission reduction of 1,107,189 $tCO_2/year$ were achieved. This results confirmed that EIP initiative based on industrial symbiosis can enhance eco-efficiency of industrial parks and harmonize economy and environment. However, there are obstacles like absence of interagency coordination and cooperation, laws and institutional barriers, increased demand for local governments, funding for project investment. Thus, to utilize EIP initiative as a strategic tool for competiveness and environmental management of industrial parks, it needs intergovernmental collaboration and interdisciplinary approach to lower barrier in implementation.

• Journal of agricultural medicine and community health
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• v.34 no.3
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• pp.303-315
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• 2009

Objectives: This study, as for activating measures for capable medical physicians to penetrate into the public health sector, is to provide a basic informations which are used for the enlargement of human resources of physicians in the public health sector, by investigating the perception of physicians, who are now working in the public health center, on the training and development of physicians in the public health sector. Methods: The subjects of this study were 126 individuals. The data was analyzed by frequency analysis using SPSS ver. 17.0K. Results: According to the investigation of 'how to support physicians in public health sector', the necessity of almost questions is considered to be important. Especially, regarding to investigation on 'obstacles of physicians' entrance to public health sector', 'relatively low salary' and 'lack of promotion chances' were thought to be considerable. The most significant education programs to work for public health sector is to improve the ability of health administration planning and service performance. Conclusions: The important methods to reinforce and easily obtain the human resources of physicians in public health sector are not only to improve the penetration of physicians to public health sector, but also to enhance the ability of present physicians, even though sufficient recruitment of physicians is essential.