• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.8 s.350
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• pp.91-96
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• 2006

High efficiency switching mode circuits such as class I amplifiers have been well known in the MHz frequency range. The class E amplifier is a type of switching mode amplifier offering very high efficiency approaching 100%. In this paper, the class E amplifier has been designed by using the harmonic balance method of circuit simulator. The designed amplifier is realized by using pHEMT and microstrip line, shows 66% power added efficiency (PAE) at 2.4GHz with 17.6dBm output power. With -3dBm input power of wireless LAN, measured output spec01m can meet the required IEEE 802.11g standard spectrum mask. That means the required amplifier back off of 9dB from $P_{ldB}$ to satisfy the required wireless LAN spectrum mask.

• Journal of the Korean Home Economics Association
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• v.32 no.1
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• pp.199-210
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• 1994

My purpose in the paper is to research on what is the most productive education method for the Students for Future Dietitian(SFD) to be applied during there field training & practice. Furthermore it is an attempt to elucidate what is the most necessary education program for the field training & practice for SFDs. Five questionnaires were given to SFDs dealing with nutrition purchase hygienic facilities and official management in order to check and evaluate the current situation and problems on the education of field training & practice for SFDs Also I chose 140 SFD's who had been working in the field for at least one week or one month in 1992 and statistical processing were utilized and analyzed by SAS package. One of the most notable problems SDFs faced with during meal planning it is the fact that they had been educated and requested for the cut of food expenditure rather than the supply of scientifically balanced-nutrition meals for working people, SFDs also faced with of information on the quantity and facilities management from the dietitian in the company. my research revealed that dietitian's teaching method for SFDs still remains in a very primitive way and accordingly the efficient way to solve these problems shall be established by a computerized education program through which dietitians can provide well-balanced meals for working people when they are assigned to the company. In this regard we must consider that we have to enact certain law to be applied to a dietitian. In another words we should emphasize actual experiences of SFDs' knowledge accumulated through the field training & practice before they work at the company. Consequently it is a time to reconsider the importance of well-balance dietitian program offering an opportunity for SFD which can contribute to improvement of health's condition for the working people.

• Biomedical Science Letters
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• v.10 no.4
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• pp.515-521
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• 2004

To measure regional cerebral blood volume (rCBV) with perfusion MR imaging of cerebral fat embolism by neutral fat and free fatty acids in cats. Triolein (group 1, n=15), oleic acid (group 2, n=9) and linoleic acid (group 3, n=11) were infused into unilateral internal carotid artery using microcatheter through the transfemoral approach. PVA particle was used as a non-fat embolic material in a control group (group 4, n=9). Perfusion-weighted MR image was obtained at 30 minutes and 2 hours postembolization, based on T2-and diffusion-weighted images. The data of lesion and contralateral normal area were transferred to personal computer, time-to-signal intensity curve was drawn and trans for used to △R2/sup */ curve in regular order. The process in the personal computer was done by using the author's developmental image processing program and interactive data language (IDL) softwares. Statistical significance was approved by paired t-test and ANOVA. rCBV of the lesion was decreased comparing to the normal area in all groups. The ratios of rCBV were as follows (group No, at 30 minutes, at 2 hours); group 1,32％, 51％; group 2, 30％, 44％; group 3, 39％, 61％; group 4, 21％, 36％. rCBVs of 2 hours was significantly increased compared to those of 30 minutes in all groups (P<0.005). rCBV was decreased at 30 minutes in cerebral fat embolism and recovered a little, but significantly at 2 hours. Perfusion-weighted images was useful method in offering hemodynamic information in cerebral fat embolism.

• The Mathematical Education
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• v.59 no.3
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• pp.237-254
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• 2020

The current study investigated the relationships between mathematical knowledge for teaching and the mathematical quality in instruction in order to gain insight about teacher education for secondary teachers in South Korea. We collected and analyzed twelve high school teachers' scores of the multiple-choice assessment for mathematical knowledge for teaching developed by the Measures of Effective Teaching project. Their instruction was video recorded and analyzed with the mathematical quality in instruction developed by the Learning Mathematics for Teaching project. We also interviewed the teachers about how they planned and assessed their instruction by themselves in order to gain information about their intention and interpretation about instruction. There was a statistically significant and positive association between the levels of mathematical knowledge for teaching and the mathematical quality in instruction. Among three dimensions of the mathematical quality in instruction, mathematical richness seemed most relevant to mathematical knowledge for teaching because subject matter knowledge plays an important role in mathematical knowledge for teaching. Furthermore, working with students and mathematics as well as students participation were critical to decide the quality of instruction. Based on these findings, the current study discussed offering opportunities to learn mathematical knowledge for teaching and philosophy about how teachers need to consider students in high schools particularly in terms of constructivism.

• Archives of Plastic Surgery
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• v.40 no.4
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• pp.304-311
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• 2013

With an increasing emphasis on microsurgery skill acquisition through simulated training, the need has been identified for standardised training programmes in microsurgery. We have reviewed microsurgery training courses available across the six continents of the World. Data was collected of relevant published output from PubMed, MEDLINE (Ovid), and EMBASE (Ovid) searches, and from information available on the Internet of up to six established microsurgery course from each of the six continents of the World. Fellowships and courses that concentrate on flap harvesting rather than microsurgical techniques were excluded. We identified 27 centres offering 39 courses. Total course length ranged from 20 hours to 1,950 hours. Student-to-teacher ratios ranged from 2:1 to 8:1. Only two-thirds of courses offered in-vivo animal models. Instructions in microvascular end-to-end and end-to-side anastomoses were common, but peripheral nerve repair or free groin flap transfer were not consistently offered. Methods of assessment ranged from no formal assessment, where an instructor monitored and gave instant feedback, through immediate assessment of patency and critique on quality of repair, to delayed re-assessment of patency after a 12 to 24 hours period. Globally, training in microsurgery is heterogeneous, with variations primarily due to resource and regulation of animal experimentation. Despite some merit to diversity in curricula, there should be a global minimum standard for microsurgery training.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.49-58
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• 2020

This study was conducted to identify the changes in academic self-efficacy and self-directed learning ability after applying flipped learning using media convergence to the basic nursing practice courses. It is offering flipped learning to 22 students from the experimental group and 26 students from the control group. Data were collected from August 27 to December 3, 2019. The difference in academic self-efficacy before and after the flipped learning was no significant difference between the two groups. However, the difference in self-directed learning ability was 11.32 points in the experimental group and 0.23 points in the control group (t=2.32, p=.027). According to the results of this study, flipped learning using media convergence was found to be an effective teaching method to improve self-directed learning ability of students. Therefore, it is necessary to study the expanded application of flipped learning using media convergence to various nursing subjects.

• Journal of Korean Society of Rural Planning
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• v.8 no.2 s.16
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• pp.27-41
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• 2002

This research is written for offering an approach to activate the stagnated industry of the tourist farm through analysis of the current operational problems and situation on some existing tourist farm nominated as such by the authority. There will be some considerations from three different categories : local autonomous groups, tourist farm associations and farm owners. On the other hand, it is assumed that this research can also be utilized as a basic material for activating the tourist farms in the suburban area of Taegu City. The operational problems in the suburban area of Taegu City are as follows : lack of a specialized Product development, the farm operation fund, lack of operational or management ability, lack of public information, etc. There are other Problems regarding law, institution and supporting : complexity of the current system involving all kinds of permission, shortage of financial and taxation supporting, lack of training an expert manpower, lack of ability and cooperation of a deskclerk in charge, etc. Here are some suggestions taking into consideration a respective sector of local autonomous group, tourist farm associations and farm owners for activating the tourist farms in the suburban area of Taegu City. First, a mental turnabout toward a tourist farm is needed from local autonomous groups. The law and institutional base should be arranged while the financial and taxation support is materialized. Second, tourist farm associations should amend or reinforce the existing institution to refresh the current recognition toward the tourist farm through many publicity activities. On the other hand, they should develop the overall tourist farm industry into a better service industry of the rural community by keeping an active system of cooperation with other related groups. Finally, It is advised that they should conceive farms and facilities which can symbolize the tourist farm from the stage of the first construction. In addition to a four-season souvenir development, an effective publicity activity and rational investment management. Above all, they should train themselves in terms of a service spirit before they see the prosperity of the tourist farm community.

• The Journal of Korean Association of Computer Education
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• v.13 no.2
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• pp.25-34
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• 2010

The Internet has brought us a new paradigm called WEB 2.0 which inherently represents the openness, participation, sharing, and cooperation. The WEB 2.0 has rendered people to actively participate in the creation of information and to dynamically interact with others to build mutual knowledge-bases, introducing a whole new web environment. One of the most representative techniques demonstrating the value of the WEB 2.0 is the WIKI which is essentially based on the 'Collective Intelligence' and the 'Wisdom of Crowds'. So far, the WIKI has drawn lots of attention for its potential as an educational tool. In this research, we explored the educational potential of the WIKI by investigating various programs and web-based tools offering WIKI services, and then, analyzing the usage model and characteristics of its users. Based on the analysis, we developed a WIKI-based instructional model and also proposed concrete lesson plans adopting this model. Besides, we introduced preliminary methodologies on the active use of the WIKI in the Edunet and the Cyber Home Learning System as well.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.1014-1023
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• 2013

Rapid developments of Information and Communication Technologies(ICT) have made people learn with online contents allowing learning at onilne universities. The environments of offering educational contents at online universities differ from those at offline-based ones, so that alternative variables need to be considered in order to enhance learning effectiveness in online settings. In this study, the effects of Self-Regulated Learning(SRL) and motivation on learner-instructor interactions and academic performance in an online university were addressed. As a result, SRL and motivation not only directly affected both interactions and achievements, but also indirectly affected achievements via interactions. Also, learner-instructor interactions were directly effective on learning achievements. The implications of the research included comprehensive understandings of the structural relationships of teaching- and learning-related variables on learning. Suggestions were made based on the results.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.351-355
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• 2010

The service which is required wide bandwidth is growing in these days, so building up High Speed communication system is being required. The Task Force team of IEEE 802.3ah set the EPON as a standard; next generation subscriber access network. For offering a high quality service, 10G EPON that is changed from 1Gbps uplink downlink bandwidth to 10Gbps is come up. Although Kramer had studied 10G EPON there was a QoS limitation, when load is low, End-to-End maximum delay is increased. This paper is suggesting time synch ronization method, resource reservation method, band width allocation method. We confirmed that 10EPON was able to offer quality service by the result of the OPNET.