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        • KCI등재

          Initial adhesion of bone marrow stromal cells to various bone graft substitutes

          조영재,김경화,구기태,김태일,설양조,이용무,구영,정종평,류인철 대한치주과학회 2011 Journal of Periodontal & Implant Science Vol.41 No.2

          Purpose: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. Methods: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with β-tricalcium phosphate (TCP), and pure β-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. Results: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. Conclusions: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment. Purpose: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. Methods: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with β-tricalcium phosphate (TCP), and pure β-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. Results: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. Conclusions: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment.

        • KCI등재

          플립러닝 기반의 PBL 수행지원체제 모형 개발

          조영재 학습자중심교과교육학회 2019 학습자중심교과교육연구 Vol.19 No.12

          The purpose of this study was to develop a model of the flipped learning-based PBL performance support system for professors in university classes. To this end, this study applied the development research method based on the ADDIE model and, first of all, derived the core value and core activity process of the flipped learning PBL performance support system through literature, case studies, and demand analysis. Then, the support structure needed for the process was found, and the blending strategy was established to complete Second, the draft of the model was modified and supplemented through expert formation evaluation to complete the final improved model. Third, feasibility tests were conducted from a group of experts to verify the validity of the completed model. The results of the study are as follows. Key values of the model were derived after literature, case analysis and demand analysis according to the content analysis method. An integrated process of integrating flip-learning and PBL was also derived. The supporting structure was selected as a teaching guideline, related information, and tool. Blending was selected as learning environment, method, strategy, medium and content according to blending strategy. These results were summed up to complete the model's drafted. Through the expert formation assessment, the following were supplemented: First of all, learning links in on- and off-line environments and feedback steps for each course were supplemented. Second, the process of adding learner activity levels, presenting direction of performance promotion, and pre-analysis refinement was supplemented. Through this process, the improved model plan was completed. The results of the feasibility test (CVI) of the expert group were evaluated to be positive in the field of explanation, usefulness, feasibility, understanding and universality. This study systematized the performance support of PBLs based on flip-learning. It also provides a variety of facilitation processes for each stage of performance. Therefore, this study will help with the practical operations required for the training site. 본 연구는 대학수업에서 교수자를 위한 플립러닝 기반 PBL 수행지원체제의 모형을 개발하는 것을 목적으로 하였다. 이를 위해 본 연구는 ADDIE 모형에 근거한 개발연구방법을 적용하였고, 그 절차로 첫째, 문헌 및 사례연구와 요구분석을 통해 플립러닝 기반 PBL 수행지원체제의 핵심가치, 핵심활동 프로세스를 내용분석방법에 따라 도출하였다. 그리고 프로세스에 필요한 지원구조와 블렌딩 전략을 수립하여 모형의 초안을 완성하였다. 둘째, 전문가 형성평가를 통해 모형의 초안을 수정·보완하여 최종 개선된 모형을 완성하였다. 셋째, 완성된 모형의 타당성을 검증하기 위하여 전문가 집단으로부터 타당도 검사를 실시하였다. 연구결과는 문헌 및 사례, 요구분석을 질적 내용분석방법을 사용하여 모형의 핵심가치를 도출하였고, 플립러닝과 PBL을 통합한 통합형 프로세스를 도출하였다. 지원구조는 교수지침과 관련정보, 도구로 선정하였다. 블렌딩은 블렌딩 전략에 따라 학습환경, 방법, 전략, 매체, 내용으로 선정하여 모형의 초안을 완성하였다. 전문가 형성평가를 통하여 온·오프라인 환경에서의 학습연계와 각 과정별 피드백 단계를 보완하고, 학습자 활동단계 추가, 수행 촉진 방향성 제시, 사전분석 정교화 과정을 보완하여 개선된 모형안을 완성하였다. 전문가 집단의 타당도 검사(CVI) 결과 설명력, 유용성, 타당성, 이해도, 보편성에서 본 연구결과가 긍정적인 것으로 평가되었다. 본 연구는 교수자를 위한 플립러닝 기반의 PBL 수행지원을 체계화하고, 각 수행단계에 필요한 다양한 촉진 과정을 제시하고 있어 교육현장에 필요한 실제적 운영에 도움이 될 것이다.

        • KCI등재

          학교성과급 정책종결 요인 분석

          조영재 한국교육정치학회 2016 敎育政治學硏究 Vol.23 No.1

          '스콜라' 이용 시 소속기관이 구독 중이 아닌 경우, 오후 4시부터 익일 오전 7시까지 원문보기가 가능합니다.

          The purpose of this study is to seek termination factors of school based merit pay policy. The process of the policy termination has been analyzed in three categories of the political environment, inherent characteristics, and constraints. Findings are as follows. The termination process has been mainly influenced by the political environment as termination supportive groups, powerful politicians, change in education minister, and an introduction of new relevant policy. Also, the inherent characteristics have affected the termination. The policy objectives have been overlapped with other policies, and the problems appeared in the policy implementation process have not been addressed. Under these circumstances, the merit pay policy has been under the favored conditions of policy termination. However, the education ministry has played a role of constraints which keep the merit pay policy from being terminated. In spite of the constraint, the merit pay policy comes to termination in 2016. From this study, it is reaffirmed that the political environment is a leading factor of education policy termination in our society. 이 연구의 목적은 학교성과급 정책종결 요인을 찾는 가운데 왜 학교성과급 정책이 정책종결에 이르게 되었는지를 분석하는 데 있다. 학교성과급 정책종결 과정은 정책종결을 유발한 정책의 정치적 환경, 내재적 특성, 제약요인으로 구분하여 분석되었다. 분석결과, 학교성과급 정책종결에는 정책주도자의 교체, 정책종결을 지지하는 집단의 연합, 정치적으로 유력한 협력자의 옹호, 새로운 관련 정책의 등장이라는 정치적 환경의 영향이 크게 작용했다. 그리고 학교성과급 정책은 다른 정책들과 정책이 추구하는 목표와 내용이 중복되거나 정책집행 과정에서 발생하는 문제의 해결이 쉽지 않은 내재적 특징을 보였다. 이러한 정치적 환경과 정책의 내재적 특징이 정책종결을 유도하는 과정에서 교육부의 동태적 보수주의는 학교성과급 정책의 종결을 제약하는 요인으로 작용했다. 이 연구를 통해 우리사회의 교육정책 종결은 정책형성 못지않게 정치적 영향을 크게 받는다는 사실을 다시 한 번 확인할 수 있었다.

        • KCI등재

          대학수업 실행공동체의 창의적 문제해결 증진을 위한 블렌디드 액션러닝 프로그램 개발

          조영재,김미호,박수홍 학습자중심교과교육학회 2018 학습자중심교과교육연구 Vol.18 No.24

          The purpose of this study was to develop a blended action learning program to enhance creative problem solving capability of the executing community in university class. The process to achieve the purpose of this study is as follows. First, the core value of the program and the core learning activity process were derived through literature research and case studies. Then, we found the key support elements for each process, established a blending design strategy, and completed the program draft. Second, the draft of the program was revised and supplemented through the evaluation of professional formation, and the final improved program was completed. Third, to verify the validity of the completed program, we conducted a validation test from the expert group. As a result of the validation test, it was positively evaluated that the Community of Practice program for creative problem solving ability had explanatory power, usefulness, validity, understanding, and universality. 본 연구는 대학수업에서 실행공동체의 창의적 문제해결력 증진을 위한 블렌디드 액션러닝 프로그램 개발을 목적으로 하였다. 본 연구의 목적을 달성하기 위해 첫째, 문헌연구, 사례연구를 통해 실행공동체의 창의적 문제해결 증진을 위한 블렌디드 액션러닝의 핵심가치, 핵심학습활동 프로세스를 도출하였다. 그리고 각 프로세스에 필요한 핵심지원요소를 찾아 블렌딩 설계 전략을 수립하고 프로그램 초안을 완성하였다. 둘째, 프로그램의 초안을 전문가 형성평가를 통해 수정, 보완한 후 최종 개선된 프로그램을 완성하였다. 셋째, 완성된 프로그램의 타당성을 검증하기 위해 전문가 집단으로부터 타당화 검사를 실시하였다. 타당화 검사결과 창의적 문제해결력을 위한 실행공동체 프로그램이 설명력, 유용성, 타당성, 이해도, 보편성이 있는 것이라고 긍정적으로 평가되었다.

        • KCI등재후보

          A Choroidal Schwannoma Confirmed by Surgical Excision

          조영재,원정빈,변석호,양우익,고형준,권오웅,이성철 대한안과학회 2009 Korean Journal of Ophthalmology Vol.23 No.1

          Schwannomas rarely present as intraocular tumors and are often misdiagnosed as malignant melanoma. We describe a choroidal schwannoma confirmed by sclerouvectomy. A 30-year-old woman presented with a large nonpigmented intraocular mass of the choroid in the right eye and underwent surgical excision by sclerouvectomy. Histologically, the tumor was composed of a mixture of cellular solid components (Antoni A) and loose myxoid components (Antoni B). The tumor was eventually diagnosed as a schwannoma. Currently available ancillary studies are still of little value in definitively differentiating schwannomas from other choroidal tumors. In the case of atypical findings for a malignant melanoma, a benign neoplasm should be included in the differential diagnosis. This patient avoided enucleation by first having the mass excised. We are unaware of previous reports in which a choroidal schwannoma was diagnosed by surgical excision.

        • KCI등재

          초광대역 통신시스템 응용을 위한이중채널 6b 1GS/s 0.18um CMOS ADC

          조영재,이승훈,김영록,유시욱 대한전자공학회 2006 電子工學會論文誌-SD (Semiconductor and devices) Vol.43 No.12

          This work proposes a dual-channel 6b 1GS/s ADC for ultra wide-band communication system applications. The proposed ADC based on a 6b interpolated flash architecture employs wide-band open-loop track-and-hold amplifiers, comparators with a wide-range differential difference pre-amplifier, latches with reduced kickback noise, on-chip CMOS references, and digital bubble-code correction circuits to optimize power, chip area, and accuracy at 1GS/s. The ADC implemented in a 0.18um 1P6M CMOS technology shows a signal-to-noise-and-distortion ratio of 30dB and a spurious-free dynamic range of 39dB at 1GS/s. The measured differential and integral non-linearities of the prototype ADC are within 1.0LSB and 1.3LSB, respectively. The dual-channel ADC has an active area of 4.0mm2 and consumes 594mW at 1GS/s and 1.8V. 본 논문에서는 초광대역 통신시스템 응용을 위한 이중채널 6b 1GS/s A/D 변환기 (ADC)를 제안한다. 제안하는 ADC는 1GS/s의 신호처리속도에서 전력, 칩 면적 및 정확도를 최적화하기 위해 인터폴레이션 기반의 6b 플래시 ADC 회로로 구성되며, 입력 단에 광대역 열린 루프 구조의 트랙-앤-홀드 증폭기를 사용하였으며, 넓은 입력신호범위를 처리하기 위한 이중입력의 차동증폭기와 함께 래치단에서의 통상적인 킥-백 잡음 최소화기법 등을 적용한 비교기를 제안하였다. 또한, CMOS 기준 전류 및 전압 발생기를 온-칩으로 집적하였으며, 디지털 출력에서는 새로운 버블 오차 교정회로를 제안하였다. 본 논문에서 제안하는 ADC는 0.18um 1P6M CMOS 공정으로 제작되었으며, 1GS/s의 동작속도에서 SNDR 및 SFDR은 각각 최대 30dB, 39dB를 보이며, 측정된 시제품 ADC의 DNL 및 INL은 각각 1.0LSB, 1.3LSB 수준을 보여준다. 제안하는 이중채널 ADC의 칩 면적은 4.0mm2이며, 측정된 소모 전력은 1.8V 전원 전압 및 1GS/s 동작속도에서 594mW이다.

        • TP-26 : Thematic Poster ; The Efficacy and Safety of Prone Positional Ventilation for Acute Respiratory Distress Syndrome: Updated Study-Level Meta-Analysis of 11 Randomized Controlled Trials

          조영재,이주명,배원,이연주,박종선,윤호일,이재호,이춘택 대한결핵 및 호흡기학회 2013 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.116 No.-

          Objective: The survival benefit of prone positioning during mechanical ventilation for acute respiratory distress syndrome (ARDS) has been a matter of debate. We performed an up-to-date meta-analysis on this topic and elucidated the effect of prone positioning on overall mortality and associated complications. Methods: Randomized controlled trials (RCTs) comparing overall mortality of prone-versus-supine positioning in ARDS patients were included. Data were extracted for populations, interventions, outcomes and risk of bias. The prespecified primary endpoint was overall mortality, using the longest available follow-up in each study. The odds ratio (OR) with 95% confidence interval (CI) was the effect measure. Results: This analysis included 11 RCTs, 2,246 total adult patients, and 1,142 patients ventilated in the prone position. Prone positioning during ventilation significantly reduced overall mortality in the random effect model (OR: 0.77; 95% CI: 0.59-0.99). In addition, the effects were measured for the subgroup in which the duration of prone positioning was >10 hours/session, compared to the subgroup with a short-term duration of prone positioning (OR: 0.62; 95% CI: 0.48-0.79). Prone positioning was significantly associated with pressure ulcers (OR: 1.49; 95% CI: 1.18-1.89) and major airway problems (OR: 1.55; 95% CI: 1.10-2.17). Conclusions: Ventilation in the prone position significantly reduced overall mortality in patients with severe ARDS. An adequate duration of prone positioning was significantly associated with a reduction in overall mortality. Objective: The survival benefit of prone positioning during mechanical ventilation for acute respiratory distress syndrome (ARDS) has been a matter of debate. We performed an up-to-date meta-analysis on this topic and elucidated the effect of prone positioning on overall mortality and associated complications. Methods: Randomized controlled trials (RCTs) comparing overall mortality of prone-versus-supine positioning in ARDS patients were included. Data were extracted for populations, interventions, outcomes and risk of bias. The prespecified primary endpoint was overall mortality, using the longest available follow-up in each study. The odds ratio (OR) with 95% confidence interval (CI) was the effect measure. Results: This analysis included 11 RCTs, 2,246 total adult patients, and 1,142 patients ventilated in the prone position. Prone positioning during ventilation significantly reduced overall mortality in the random effect model (OR: 0.77; 95% CI: 0.59-0.99). In addition, the effects were measured for the subgroup in which the duration of prone positioning was >10 hours/session, compared to the subgroup with a short-term duration of prone positioning (OR: 0.62; 95% CI: 0.48-0.79). Prone positioning was significantly associated with pressure ulcers (OR: 1.49; 95% CI: 1.18-1.89) and major airway problems (OR: 1.55; 95% CI: 1.10-2.17). Conclusions: Ventilation in the prone position significantly reduced overall mortality in patients with severe ARDS. An adequate duration of prone positioning was significantly associated with a reduction in overall mortality.

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