• 디지털융복합연구
• /
• 제16권10호
• /
• pp.1-9
• /
• 2018

본 연구의 목적은 첨단 ICT의 활용도를 높이고 국가 간 교육 교류협력 활성화에 기여하는 온라인 국제교류 협력학습의 개념과 유형에 대해서 살펴보고, 유형별 수업 설계모형을 제시하는 데 있다. 이를 위해 온라인 국제교류 협력학습 관련 시범사업 및 선행연구를 고찰하였다. 그 결과, 온라인 국제교류 협력학습은 첨단 ICT를 기반으로 언어적, 문화적으로 이질적인 학생, 교사, 현장전문가가 상호작용하고 협력함으로써 지식을 탐구하고 구성해가는 구성주의 기반의 교육방법임을 확인하였다. 유형으로는 원격 화상 수업 중심의 실시간 교류학습과 웹사이트 기반 과제 중심의 비실시간 교류학습이 있었고, 이러한 유형별 특징을 고려한 PPIE(Plan-Preparation-Interaction-Evaluation) 수업 설계모형을 제시하였다. 본 연구의 결과가 온라인 국제교류 협력학습 활성화에 기여할 것으로 기대한다.

• 융합정보논문지
• /
• 제11권8호
• /
• pp.23-28
• /
• 2021

본 논문에서는 재귀형 크로스아이(retrodirective cross-eye) 재머 신호와 레이다 반사 신호 비(Jamming and radar return Signal Ratio: JSR)에 따른 모노펄스 레이다의 추적 오차의 변화를 분석하였다. 레이다 추적 오차를 계산하기 위한 방법으로 크로스아이 재머 이득(G_c)이 사용되었고, 재머 이득과 재머 신호와 레이다 반사 신호의 비(JSR)의 관계를 수식으로 표현하였다. 모노펄스 레이다와 재머 사이의 조우각과 JSR을 동시에 변화 시키면서 레이다 추적 오차를 분석하였다. 그리고 재머 두 신호간의 위상(ϕ) 차이와 JSR의 변화를 분석 한 결과 두 재머 신호 위상 차이가 180°에 가까워질수록 추적 오차가 커지고 JSR이 20dB이상이 되면 추적 오차가 일정 수준을 유지하게 되는 것을 볼 수 있다. 본 연구는 레이다 반사 신호의 비(JSR)에 따른 모노펄스 레이다의 추적 오차에 대한 결과를 제시하였고 추적 방향, 두 재머 신호 위상차, 두 재머 신호 크기 비율 등에 따른 복합적인 추적오차 분석 결과를 제시하였다.

• 한국수소및신에너지학회논문집
• /
• 제6권2호
• /
• pp.53-63
• /
• 1995

차세대의 새로운 발전방식인 용융탄산염형 연료전지 시스템개발 사업중 실용 스택개발을 위하여 전극유효연적이 $100cm^2$ 인 단위전지를 10단 적층한 Cross Flow형 MCFC스택을 제작하고 2성능측정설비를 구성하여 장기운전시험을 실시하였다 연료로는 $H_2/CO_2/H_2O$의 비율을 72%/18%/10% 로 조성한 가스를 이용하고 산화제가스로는 $O_2/CO_2$ 및 $Air/CO_2$ 비율이 33%/67%, 70%/30%가 되는 가스를 이용하여 운전할때의 초기성능 및 15A($150mA/cm^2$) 정부하 상태에서의 장기운전시험시의 전압 강하율을 조사하였다. 운전시간 310시간이 경과된 후의 스택전압은 8.39V이었고 이때의 출력은 125.8W를 보여주었다. 한편 1845시간이 경과한후 공기를 산화제로 이용하는 경우 전압은 6.95V로서 출력 104W를 나타내고 있다. 초기성능치에 의한 에너지 변환효율은 이용율이 40%인 경우 29.65%이었고 80%로 증가하는 경우 약 51.5%가 된다. 1840시간의 경과한때 까지의 전압 강하율은 약 52.4mV/1000hr로서 이전의 스택보다는 전압강하율이 감소되고 있으며 스택의 성능 저하의 주요한 요인은 개회로 전압의 저하로 내부단락동에서 기인하는 것으로 여겨진다. 또한 장기운전사 스택내부에서의 단위전지 전압분포가 균일하지 않음을 알 수 있어 이에 대한 개선을 필요로 한다.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2019년도 춘계학술대회
• /
• pp.111-111
• /
• 2019

Glycyrrhizae radix is one of the most frequently prescribed ingredients in Oriental medicine, and G. radix extract has been shown to exert anti-cancer effects. However, the cellular and molecular mechanisms of apoptosis by G. radix are poorly defined. In the present study, it was examined the biochemical mechanisms of apoptosis by water extract of G. radix (WEGR) in human bladder T24 cancer cells. It was found that WEGR could inhibit the cell growth of T24 cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies, DNA fragmentation and increased populations of annexin-V positive cells. The induction of apoptotic cell death by WEGR was connected with an up-regulation of pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL proteins, and inhibition of apoptosis family proteins (XIAP, cIAP-1 and cIAP-2). In addition, apoptosis-inducing concentrations of WEGR induced the activation of caspase-9, an initiator caspase of the mitochondrial-mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. WEGR also induced apoptosis via a death receptor-mediated extrinsic pathway by caspase-8 activation, resulting in the down-regulation of total Bid and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. Taken together, the present results suggest that WEGR may be a potential chemotherapeutic agent for the control of human bladder cancer cells.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2019년도 춘계학술대회
• /
• pp.113-113
• /
• 2019

Diallyl trisulfide (DATS) is an organic polysulfide compound found in garlic. Although certain studies have demonstrated that DATS possesses strong anti-inflammatory activity, the underlying molecular mechanisms remain largely unresolved. In this study, we examined whether DATS exerts anti-inflammatory activity and investigated the possible mechanisms. Our results indicated that DATS significantly suppressed the lipopolysaccharide (LPS)-induced release of nitric oxide (NO) and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase-2 expression at the transcriptional and post-transcriptional levels in RAW 264.7 macrophages. DATS also down-regulated Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 expression, and inhibited nuclear translocation of nuclear transcription factor-kappa B (NF-${\kappa}B$) in LPS-stimulated 264.7 macrophages. Furthermore, we found that these inhibitory effects of DATS were associated with the inhibition of chemokine receptor (CXCR4) and ligand (CXCL12) expression, and reactive oxygen species generation. Overall, the present data indicated that DATS had anti-inflammatory effects on LPS-activated macrophages, possibly via inhibiting the TLR4/NF-kB and/or chemokine signaling pathways, and DATS could be a potential drug therapy for inflammation and its associated diseases.

• Industrial Engineering and Management Systems
• /
• 제1권1호
• /
• pp.79-86
• /
• 2002

This paper proposes a new algorithm for estimating ARMA model parameters. In estimating ARMA model parameters, several methods such as generalized least square method, instrumental variable method have been developed. Among these methods, the utilization of a bootstrap type algorithm is known as one of the effective approach for the estimation, but there are cases that it does not converge. Hence, in this paper, making use of a cross correlation function and utilizing the relation of structural a priori knowledge, a new bootstrap algorithm is developed. By introducing theoretical relations, it became possible to remove terms, which is liable to include much noise. Therefore, this leads to robust parameter estimation. It is shown by numerical examples that using this algorithm, all simulation cases converge while only half cases succeeded with the previous one. As for the calculation time, judging from the fact that we got converged solutions, our proposed method is said to be superior as a whole.

• 비교문화연구
• /
• 제19권
• /
• pp.339-358
• /
• 2010

This paper aims to propose teaching plans based on individual learner's experience and from a cross-cultural viewpoint by applying Currere as a method of Korean life-culture education. Current Korean culture education programs are not systematic, and are being executed without differentiation from language education. Thus, this study proposes Korean life-culture teaching plans based on the method of Currere. We suggested Currere teaching-learning stages and strategies for Korean language learners by adapting Pinar's and Jeong Seong-a's method of Currere. The Currere teaching-learning stages consisted of introduction, regression, progression, theme analysis, data analysis, group discussion, and integration. Although the method of Currere is implemented through autobiographic writing, this study added the strategies of 'personal experience telling' and 'schema utilization and background knowledge provision'. In order to enhance the applicability of Currere to Korean life-culture education, we suggested teaching plans for the theme of "How to dispose rubbish" as an example. We suggested detailed teaching plans that teachers can apply in the actual classroom. We expect that these teaching plans may be applied to actual classes so that Korean culture education may not be limited to the acquisition of knowledge, but be linked to their real life.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.1076-1079
• /
• 1993

A fuzzy digital controller is combined an autopilot system for compensating the cross coupling effect of the induced roll due to the dynamic characteristic of three fin torpedo. However the utilization of fuzzy chip has many interfacing problems with typical microprocessors of the guidance and control unit. Since a fuzzy digital controller on a microprocessor uses a finite word length A/D converters arul D/A converters, ADC and DAC may generate nonlinear effects such as deadband and limit cycle phenomena. In this paper, the robustness of fuzzy digital controller is tested with ADC a finite word length.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1247-1250
• /
• 2008

This presentation highlights work from the authors' laboratories on the various kinds of oxide optical materials, mainly luminescence and pigment materials with different forms (powder, core-shell structures, thin film and patterning) prepared by the Pechini-type sol-gel (PSG) process. The PSG process which uses the common metal salts (nitrates, acetates, chlorides etc) as precursors and citric acid (CA) as chelating ligands of metal ions and polyhydroxy alcohol (such as ethylene glycol or poly ethylene glycol) as cross-linking agent to form a polymeric resin on molecular level, allowing the preparation of many forms of luminescent materials.

• 한국치위생학회지
• /
• 제10권4호
• /
• pp.745-755
• /
• 2010

Objectives : The research of dental hygiene has made considerable progress over the past 10 years toward developing a unique body of knowledge for guiding education, practice, and profession. The purpose of this study was to determine Barriers to Research Utilization among Dental Hygiene Researchers. Methods : This study used cross-sectional design, self-reported questionnaire. That was consisted of 31 items(5 categories), reliability was tested(Cronbach's Alpha=0.882). The subjects were 117, mean age was $36.1{\pm}9.3$. They were consisted of full-time faculty (35.9%) and the doctoral course(61.0%). Results : The greatest barriers in dental hygiene research were 'Dental hygienists are isolated from knowledgeable colleagues with whom to discuss with' in Dental Hygienist category and 'The facilities are inadequate for implementation' in setting. In Research category, 'the research has not been replicated' and 'the relevant literature is not complied in one place' in presentation were the greatest. The researchers who were the twenty's, received dental hygiene license after 2000 year and studying for the master's degree had more barriers in all categories significantly. Conclusions : This finding provided evidence that there are barriers in dental hygiene research and we found the junior researchers have more difficulties. To improve this barriers, dental hygiene related associations need to focus on the research utilization and encourage them to attend conferences. In addition, research related education should be provided to them. Further study is essential to investigate the barriers for the established researchers in dental hygiene and to find specific solutions.