• Journal of Korean Elementary Science Education
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• v.26 no.1
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• pp.117-130
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• 2007

This study investigated the university proffssors', pre-service teachers' and in-service teachers' perceptions of the specialized science education courses in the 11 national universities of education in Korea, analyzed their perception differences, and made suggestions the future directions for the specialized courses. For this study, 46 university professors, 402 in-service teachers, and 336 pre-service teachers were participated nationwide. The results show that there were significant differences in their perceptions between the three groups. For university professors, for example, the acquisition of science content knowledge appeared to be the most important objective of the courses, whereas the other groups preferred the acquisition of more practical knowledge and skills that they could easily use and apply in their classroom teaching later. The university professors tended to think that the science specialized courses would be very useful to the teachers' teaching and contribute to developing their professionality. On the contrary, the in-service and pre-service teachers tended to think that the courses would be not so useful because science theories construct the courses rather than practical knowledge. The implications of these findings are discussed in relation to the future science teacher education.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6A
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• pp.601-608
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• 2011

In OFDMA(Orthogonal Frequency Division Multiple Access) based multi-hop networks, the subcarrier-pairing scheme using the SNR(Signal-to-Noise Ratio) has been proposed as the best solution. But, this scheme is not optimal in cognitive radio system, because of the power control due to the interference to the primary user. In this paper, we propose two subcarrier-pairing schemes for OFDMA based 2-hop cognitive radio systems. One is the IT(Interference channel gain) scheme considering only the interference channel gain, and the other is the CI(Channel SNR over interference channel gain) scheme considering the ratio of channel SNR to interference channel gain. The results show that the CI scheme has the best performance in which throughput is improved more than 10% in comparison with other schemes.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3327-3332
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• 2011

Antimicrobial peptides have recently gained the much attention because of their ability to make defense system from attacking bacterial infections. Drosocin has been considered as very attractive antibiotic agents because of low toxicity against human erythrocytes and active at the low concentration. We have studied the structureactivity relationship of a glycopeptide drosocin focused on the N-acetyl-D-galactoside at $Thr^{11}$ residue. Based on the radial diffusion assay, we found that the acetylation of carbohydrate moiety increased the antimicrobial activity and the $Pro^{10}$, present in the middle of drosocin plays an important role in the antimicrobial activity. Our results provide a good lead compound for further studies on the design of drosocin-based analogues targeting glyco linked Thr site.

• Natural Product Sciences
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• v.12 no.3
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• pp.144-149
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• 2006

The immediate-type allergic reaction (anaphylaxis) is involved in many allergic diseases such as asthma, allergic rhinitis, and sinusitis. The discovery of drugs for the treatment of immediate-type allergic diseases is a very important subject in human health. In this study, we investigated the effect of Rubus coreanus Miq.(Rosaceae) unripe fruits (RCF) on mast cell-mediated allergic reaction and inflammatory cytokine secretion. RCF inhibited compound 48/80-induced systemic reactions in mice. RCF attenuated immunoglobulin (Ig) E-mediated local allergic reactions. In addition, RCF dependently reduced histamine release from rat peritoneal mast cells local allergic reactions. In addition, RCF dependently reduced histamine release from rat peritoneal mast cells activated by compound 48/80 or IgE. Furthermore, RCF decreased the phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated tumor necrosis factor $(TNF)-{\alpha}$ and interleukin (IL)-6 secretion in human mast cells. Our findings provide evidence that RCF inhibits mast cell-derived immediate-type allergic reactions.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.12 no.1
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• pp.29-37
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• 2018

In this research, one's ability to perform activities of daily living, body pain, and emotional states of elders who live alone and elders who live with others were compared to investigate which factors affect senior's health state. The data was collected from 88 seniors and analyzed for the comparison. Compared to seniors who live with others, elders who live alone had lower activity of daily livings, stronger body pain, and instability in emotional states. These 3 aspects showed a statistical significance of correlation. As a result of further analysis, not only residential types(living alone or living with others), but also life pattern(indoor or outdoor) is affected on the results. It is expected that the results of this research could be used as basic data for physiological index to evaluate senior's health state and care service for seniors who live alone.

• Ocean and Polar Research
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• v.29 no.1
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• pp.33-42
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• 2007

To obtain the overall distribution patterns and characteristics of the East Sea Intermediate Water (ESIW), the historical data obtained by the Japan Maizuru Marine Observatory (MMO) and the Korea Ocean Research and Development Institute (KORDI) were analyzed. To obtain water characteristics of the ESIW on isopycnal surfaces, temperature, salinity and dissolved oxygen were interpolated at every 0.01 interval of potential density. And then the interpolated values were averaged at the same potential density. This potential density average method preserved the salinity minimum layer more clearly compared to the depth average method. The potential density(${\sigma}_{\theta}$) range of the ESIW was $26.9{\sim}27.3$. The representative potential density of the ESIW was found to be 27.2, because the characteristics of the ESIW was clear at this density. From the horizontal distributions of physical properties on the isopycnal surface of $27.2{\sigma}_{\theta}$ it is suggested that the low salinity ESIW circulates anticlockwise over the whole basin with the high salinity intermediate water. The low salinity intermediate water extended from the northwestern part to the east along the sub-polar front and to the Ulleung Basin along the east coast of Korea.

• Quality Improvement in Health Care
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• v.15 no.2
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• pp.83-86
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• 2009

연구배경: 수술적 치료가 필요한 척추관 협착증 환자들은 주로 60세 이상의 고령환자로 장기간의 입원 시 기회 감염의 증대와 불필요한 의료비의 증대를 가져오게 되며, 수술 후 환자들의 재원일수의 증가는 병원의 병상가동률을 감소시키고, 전공의에게는 불필요한 업무를 증가시킨다. 연구목적: 비용 효과면에서 최적화된 진료 지침의 개발은 불필요한 의료비의 감소 및 Hospital Induced Complication을 줄여 환자 만족도를 증진시킬 수 있으며, 각 환자에 대한 전공의 업무를 줄일 수 있다. 의료기관: 서울특별시에 소재한 2,075병상의 종합전문요양기관 연구방법: 정형외과 및 신경외과의 척추관 협착증 환자의 처방을 비교하여 최적의 표준진료지침을 개발하고 최종적으로 CP Master Program(EMR 프로그램)에 입력하여 환자에게 적용하였다. 연구결과: CP 적용 전, 후 비교를 통해 재원일수는 3.8일이 감소하였으며, 이에 따라 병상 가동률 및 진료수익이 증가했으리라고 예상되며 현재 비교 검토 중이다. 또한, CP 개발 및 CP Master Program의 사용을 통한 전공의 업무 감소에 대해 검토하고 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.325-338
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• 2012

In this paper, a radio resource allocation scheme for a multi-hop relay transmission in cognitive radio (CR) system is proposed to support the employment of relay nodes in IEEE 802.22 standard for wireless regional area network (WRAN). An optimization problem is formulated to maximize the number of serving secondary users (SUs) under system constraints such as time-divided frame structure for multiplexing and a single resource-unit to every relay-hop. However, due to mathematical complexity, the optimization problem is solved with a sub-optimal manner instead, which takes three steps in the order of user selection, relay/path selection, and frequency selection. In the numerical analysis, this proposed solution is evaluated in terms of service rate denoting as the ratio of the number of serving SUs to the number of service-requesting SUs. Simulation results show the condition of adopting multi-hop relay and the optimum number of relaying hops by comparing with the performance of 1-hop system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9A
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• pp.853-866
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• 2008

In this paper, a multi-hop relaying transmission scheme is analyzed regarding its feasibility and potentiality in the IEEE 802.22-based cognitive radio (CR) environment. Shortly, basic design issues are addressed such as relay station (RS) deployment and a frame structure of physical channel to escape inter-hop interference. This paper mainly develops a radio resource management scheme based on spectrum sensing results aggregated from CR secondary nodes and improves the opportunistic spectrum sharing efficiency. In particular, a decision rule about a channel availability is made using a distributed sensing method. Subsequently, spectrum allocation and routing path decision procedures are proposed to establish a link from source to destination with a hop-by-hop manner. Simulation results show that the proposed multi-hop relaying scheme is substantially profitable in CR environments if the number of hops and RS deployment are designed in such a way that the spectrum sharing gain is larger than spectrum division loss which is inherently induced in multi-hop relaying systems.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.599-606
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• 2005

Clinical application of the cartilage formed by tissue engineering is of no practical use due to the failure of long-term structural integrity maintenance. One of the important factors for integrity maintenance is the biomaterial for a scaffold. The purpose of this study is to evaluate the difference between polylactic-co-glycolic acids (PLGA) and chitosan as scaffolds. Human auricular chondrocytes were isolated, cultured, and seeded on the scaffolds, which were implanted in the back of nude mice. Eight animals were sacrificed at 4, 8, 12, 16, and 24 weeks after implantation respectively. In gross examination and histological findings, the volume of chondrocyte-PLGA complexes was decreased rapidly. The volume of chondrocyte-chitosan complexes was well maintained with a slow decrease rate. The expression of type II collagen protein detected by immunohistochemistry and western blots became weaker with time in the chondrocyte-PLGA complexes. However, the expression in the chondrocyte-chitosan complexes was strong for the whole period. Collagen type II gene expressions using RT-PCR showed a similar pattern. In conclusion, these results suggest that chitosan is a superior scaffold in cartilage tissue engineering in terms of structural integrity maintenance. It is expected that chitosan scaffold may become one of the most useful scaffolds for cartilage tissue engineering.