• 기술사
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• 제34권4호
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• pp.41-47
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• 2001

The paper describes SR3 (Synchronous Round Robin with Reservations), a collision-free medium access control protocol for all-optical slotted packet networks based on WDM multi-channel ring topologies where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter SR3 is derived from the SRR and MMR protocols previously proposed by the same authors for the same class of all-optical networks. SRR and MMR already achieve an efficient exploitation of the available bandwidth, while guaranteeing a throughput-fair access to each node. SR3, In addition, allows nodes to reserve slots. thereby achieving a stronger control on access delays; it is thus well suited to meet tight delay requirements, as it is the case for multimedia applications. Simulation results show that SR3 provides very good performance to guaranteed qualify traffic, but also brings signigicant performance improvements for best-effort traffic. Energy effciency is an important issue for optical network since they must rely on their batteries. We present a novel MAC protocol that achieves a good energy efficiency of optical interface of the network and provides support for diverse traffic types and QoS. The scheduler of the base station is responsible to provide the required QoS to connections on the optical link and to minimise the amount of energy spend by the High speed Network. The main principles of the MaC protocol are to avoid unsuccessful actions, minimise the number of transitions , and synchronise the mobile and the base-station. We will show that considerable amounts of energy can be saved using these principles.

• Journal of Communications and Networks
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• 제3권4호
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• pp.324-333
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• 2001

The Differentiated Services (Diffserv) framework has been proposed by the IETF as a simple service structure that can provide different Quality of Service (QoS) to different classes of packets in IP networks. IP packets are classified into one of a limited number of service classes, and are marked in the packet header for easy classification and differentiated treatments when transferred within a Diffserv domain. The Diffserv framework defines simple and efficient QoS differentiation mechanisms for the Internet. However, the original Diffserv concept does not provide a complete QoS management framework. Since traffic flows in IP networks are unidirectional from one network point to the other and routing paths and traffic demand get dynamically altered, it is important to monitor end-to-end traffic status, as well as traffic status in a single node. This paper suggests a distributed QoS monitoring method that collects the statistical data of each service class in every Diffserv router and calculates edge-to-edge QoS of the aggregated IP flows by combining routing topology and traffic status. A format modeling of edge-to-edge Diffserv flows and algorithms for aggregating edge-to-edge QoS is presented. Also an SNMP-based QoS management prototype system for Diffserv networks is presented, which validates our QoS management framework and demonstrates useful service management functionality.

• 한국과학교육학회지
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• 제23권4호
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• pp.375-385
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• 2003

In an effort to provide information about the effect of Microcomputer-Based Laboratory (MBL) use in science teaching and learning on student achievement and attitudes, a review of research analyzed studies was done between 1981 and 2001, using a meta-analysis procedure. Thirty-seven published and unpublished studies were reviewed. Use of MBL was shown to be potentially effective in the following condition of class; two students, physics teaching, more than one topic, or at the college level. Appropriate research design strategies, financial support (including hardware and software), and the use of more than one instrument for assessing the effect of the MBL instruction are crucial factors for more informative research studies. While helpful in many respects, the prior research revealed a number of problems related to the use of MBL in school science teaching and learning. The prior research does not support the desired intention described in the theory-based outcomes and reveals so little about how teachers and students use MBL, how it influences their teaching and learning, and how effectively it fits into the existing science curriculum. In order to know if the integration of MBL in the existing school science is worth it or not, more careful research design and comprehensive research should be done.

• 컴퓨터교육학회논문지
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• 제16권3호
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• pp.23-30
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• 2013

인터넷 확산으로 기존 윤리와는 다른 인터넷윤리가 하나의 학문으로 인식되고 있다. 초중고를 포함하여 대학에서도 인터넷윤리가 교양과목으로 자리잡고 있으며, 본 연구자도 이 과목을 수년째 강의하고 있다. 컴퓨터과학자로서 인터넷윤리를 학생들에게 효과적으로 전달하기 위하여, 인터넷윤리 관련 동영상을 활용하고 일부 시범 실습을 실시하는 수업을 진행하였다. 최신 UCC 제시 및 이에 대한 토론도 진행하여 학생들의 인터넷윤리 이슈와 문제점을 인식시켰다. 수강생 대상의 설문조사를 통하여, 제시된 수업방식이 학생들의 관심 유도에 효과적이며 미래 인터넷윤리 실천의지 향상에 도움이 됨을 확인하였다. 본 연구는 인터넷윤리 주제들을 대학생들에게 효과적으로 전달하는 수업 사례를 제시했다는 의의를 가진다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.209-211
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• 2004

In the Langmuir-Boldgett(LB) technique, a monolayer on the water surface is transferred on to a substrate, which is raised and dipped through the surface, and one can obtain multilayers in which constituent molecules periodically are arranged in layer. The LB technique has attracted considerable interest in the fabrication of electrical and electronic device, e.g.. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules sharacterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends, which distinguishes dendrimers from conventional starlike polymers and microgels. Azobenzene dendrimer is one of the dendritic macromolecules that includes the azo-group which exhibits a photochromic character. Due to the presence of the charge transfer part, the azo-group, and having a rod-shaped structure, these compounds are expected to have the potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give a pressure stimulation into organic thin films and detect the induced displacement current.

• 고전문학과교육
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• 제16호
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• pp.29-63
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• 2008

The purpose of the study is to describe the phenomena of reading classical Korean literature in middle school classrooms. This is one of a series of fundamental works to seek a desirable direction for classical Korean literature education. The results of the study are as follows. First, it was investigated which classical Korean literature middle school students read. As a result, it was found that the students read the works given mostly in their Korean language textbooks. A modern language is used for classical Korean literature in middle school textbooks. The textbooks have the largest number of tales with four pieces, followed by novels, essays, and sijos, Korean verses. Secondly, it was investigated how middle school students read classical Korean literature. It was found that they read it in class mainly through one-way lecturing by teachers. As a result of conducting a questionnaire survey of students and teachers, it was found that the lessons in classical Korean literature did not fulfill the students' expectations. Thirdly, my own real teaching cases were arranged to be presented, in connection with the matter why students should read classical Korean literature. This matter is embodied with a teacher's short verbal explanation focusing on motivation concerning the object of study.

• 한국음향학회지
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• 제38권5호
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• pp.614-620
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• 2019

본 논문은 전역 스타일 토큰(Global Style Token, GST)을 사용하는 종단 간(end-to-end) 감정 음성 합성 시스템의 성능을 높이기 위해 각 감정의 스타일 벡터를 효과적으로 결정하는 방법을 제안한다. 기존 방법은 각 감정을 표현하기 위해 한 개의 대푯값만을 사용하므로 감정 표현의 풍부함 측면에서 크게 제한된다. 이를 해결하기 위해 본 논문에서는 k-평균 알고리즘을 사용하여 다수의 대표 스타일을 추출하는 방법을 제안한다. 청취 평가를 통해 제안 방법을 이용해 추출한 각 감정의 대표 스타일이 기존 방법에 비해 감정 표현 정도가 뛰어나며, 감정 간의 차이를 명확히 구별할 수 있음을 보였다.

• Molecules and Cells
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• 제43권7호
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• pp.607-618
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• 2020

microRNAs (miRNAs) are non-coding RNA molecules involved in the regulation of gene expression. miRNAs inhibit gene expression by binding to the 3' untranslated region (UTR) of their target gene. miRNAs can originate from transposable elements (TEs), which comprise approximately half of the eukaryotic genome and one type of TE, called the long terminal repeat (LTR) is found in class of retrotransposons. Amongst the miRNAs derived from LTR, hsa-miR-3681 was chosen and analyzed using bioinformatics tools and experimental analysis. Studies on hsa-miR-3681 have been scarce and this study provides the relative expression analysis of hsa-miR-3681-5p from humans, chimpanzees, crab-eating monkeys, and mice. Luciferase assay for hsa-miR-3681-5p and its target gene SHISA7 supports our hypothesis that the number of miRNA binding sites affects target gene expression. Especially, the variable number tandem repeat (VNTR) and hsa-miR-3681-5p share the binding sites in the 3' UTR of SHISA7, which leads the enhancer function of hsamiR-3681-5p to inhibit the activity of VNTR. In conclusion, hsa-miR-3681-5p acts as a super-enhancer and the enhancer function of hsa-miR-3681-5p acts as a repressor of VNTR activity in the 3' UTR of SHISA7.

• 대한교통학회지
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• 제28권3호
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• pp.51-57
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• 2010

본 연구는 전국의 공항 인근지역에 있는 190여개 초 중 고등학교를 대상으로 항공기 소음의 피해 현황을 파악하고, 학교의 피해의식예측 모형을 수량화이론 II류를 이용하여 구축하였고, 피해학교 교사 1,012명의 설문을 통하여 교사들의 수업진행방해 예측모형을 구축하였으며, 특히 군용/민간 공용비행장 4개소와 사격연습장 1개소 총 5개 지역의 항공기 소음을 조사하여 그 특성을 분석하였다. 그 결과를 요약하면 다음과 같다. 군용/민간 공용 공항에서의 항공기 소음 WECPNL 5개 지역 모두 피해지역 제1종 지역과 2종 지역으로 나타나 항공기 소음에 심각한 문제가 있음을 알 수 있어 대책이 수립되어야 하겠다. 학교의 항공기 소음 피해의식 모형에서 가장 영향이 높은 요인은 공항과 학교와의 거리로서 5 Km 미만에서 양의 관계를 나타내며 10 Km 이상에서 음의 관계를 나타내고 있다. 항공기 소음의 폭로시간과 폭로회수가 각각 설명이 높으며 공항의 종류와 창문의 구조에도 깊은 영향이 있음을 알 수 있고, 본 예측모형은 상관비 0.56으로서 적합성이 높다고 하겠다.

• Journal of Information Display
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• 제12권3호
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• pp.145-152
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• 2011

Since the discovery of fullerenes as a class of nanostructure compounds, many potential applications have been suggested for their unusual structures and properties. The isolated pentagon rule (IPR) states that all pentagonal carbon rings are isolated in the most stable fullerene. Fullerenes $C_n$ are a class of spherical carbon allotrope group with unique properties. Electron transfer between fullerenes and other molecules is thought to involve the transfer of electrons between the molecules surrounding the fullerene cage. One class of electron transfer molecules is the methanofullerene derivatives ([6,6]-phenyl $C_{61}$-butyric acid methyl ester (PCBM), 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid methyl ester (p-EHO-PCBM), and 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid (p-EHO-PCBA), 10-12). It has been determined that $C_{60}$ does not obey IPR. Supramolecular complexes 1-9 and 10-12 are shown to possess a previously unreported host.guest interaction for electron transfer processes. The unsaturated, cis-geometry, thiocrown ethers, (1-9) (described as [X-UT-Y], where X and Y indicate the numbers of carbon and sulfur atoms, respectively), are a group of crown ethers that display interesting physiochemical properties in the light of their conformational restriction compared with a corresponding saturated system, as well as the sizes of their cavities. Topological indices have been successfully used to construct mathematical methods that relate structural data to various chemical and physical properties. To establish a good relationship between the structures of 1-9 with 10-12, a new index is introduced, ${\mu}_{cs}$. This index is the ratio of the sum of the number of carbon atoms ($n_c$) and the number of sulfur atoms ($n_s$) to the product of these two numbers for 1-9. In this study, the relationships between this index and oxidation potential ($^{ox}E_1$) of 1-9, as well as the first to third free energies of electron transfer (${\Delta}G_{et(n)}$, for n = 1-3, which is given by the Rehm-Weller equation) between 1-9 and PCBM, p-EHO-PCBM, and p-EHO-PCBA (10-12) as [X-UT-Y]@R(where R is the adduct PCBM, p-EHO-PCBM, and p-EHO-PCBA group) (13-15) supramolecular complexes are presented and investigated.