• 제목/요약/키워드: cross feedback

검색결과 139건 처리시간 0.027초

광섬유를 이용한 광영상 단층촬영기에 관한연구 (A study on optical coherence tomography system using optical fiber)

  • 양승국;박양하;장원석;오상기;김현덕;김기문
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2004년도 춘계학술대회 논문집
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    • pp.5-9
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    • 2004
  • 본 연구에서 고분해능 측정과 저가격화 및 소형으로 제작이 가능하여 전세계적으로 많은 연구가 진행중인 광섬유를 이용한 광영상단층촬영기를 연구하였다. 광영상단층촬영기의 기돈원리로는 마이켈슨 간섭계를 이용한 것이다. 시스템의 구성으로는 광원은 분해능 및 측정범위를 고려하여 1,300nm 중심파장을 가지며 대역폭이 35nm인 상용제품의 SLD(Superluminersent diode)를 사용하였으며, 샘플내부의 영상을 검출하기 위한 간섭신호 검출방법은 기준거울이 선형적으로 이동하여 광경로를 일치하는 광지연선로를 구성하였다. 그리고 간섭계는 단일모드 광섬유를 이용하여 기본적인 마이켈슨 간섭계를 구성하였으며, 스캐너는 시준기를 이용하여 샘플에 대한 초점을 고정하도록 하였으며, 스템모터를 이용하여 스텝모터를 이용하여 샘플에 대한 횡단방향으로 이동하여 샘플의 2차원 단층영상을 측정하도록 하였다. 수광부는 소신호인 간섭신호를 검출하기 위하여 감도가 뛰어나면 잡음특성이 우수한 800~1,700nm 측정범위의 광검출기를 사용하였다. 신호처리부에서 간섭신호의 포락선 신호만을 검출하기 위하여 증폭 및 필터링 하여 A/D 변환을 거친 후 제작된 영상검출 프로그램을 이용하여 단층영상을 나타내도록 하였다. 측정결과 분해능은 약 30$\mu\textrm{m}$로서 이론식과 일치함을 확인하였으며, 탁구공의 단층영상을 측정하였다. 기본적인 마이켈슨 간섭계를 이용한 OCT시스템은 되돌아오는 간섭광의 절반이 광원부로 향하여 간섭신호의 절반이 손실되므로 검출기에서 검출된 신호가 미약하여 단층영상의 대비도를 떨어뜨린다. 이러한 문제점을 해결하기 위하여 간섭계 구성의 개선이 필요하다. 또한 측정시간을 단축하기 위하여 광지연선로의 개선으로 통해 짧은 시간내 당층영상을 얻을 수 있도록 하여야 할 것이다.기로 확장 가능한 PCS 단말기를 사용해서 위치추적을 하는 시스템이다. 이러한 시스템을 선정하게된 배경은 단말기아 망 이용료의 가격이 저렴하여 현실적으로 트럭이 쉽게 부착할 수 있다는 장점이 있으며 나아가 인터넷 단말기를 활용하여 차량과 관제센터사이에 메시지 전송 등 부가적인 서비스가 가능하기 때문이다.비교한 결과 토사 유출 억제효과는 한지형과 나지형잔디들의 혼합형(MixtureIII)과 자생처리구(MixtureV), Italian ryegrass와 자생식물의 혼합형(MixtureIV)등에서 비교적 낮은 수치를 토사유출량을 기록하였다. 이러한 결과는 자생식물들이 비록 초기생육속도는 외래도입초종에 떨어지지만 토사유출의 억제효과면에서는 이들 외래초종에 필적할 수 있음을 나타낸다고 할 수 있겠다.중량이 약 115kg/$m^2$정도로 나타났다.소 들(환경의 의미, 사람의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $

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Plasma Etching Process based on Real-time Monitoring of Radical Density and Substrate Temperature

  • Takeda, K.;Fukunaga, Y.;Tsutsumi, T.;Ishikawa, K.;Kondo, H.;Sekine, M.;Hori, M.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.93-93
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    • 2016
  • Large scale integrated circuits (LSIs) has been improved by the shrinkage of the circuit dimensions. The smaller chip sizes and increase in circuit density require the miniaturization of the line-width and space between metal interconnections. Therefore, an extreme precise control of the critical dimension and pattern profile is necessary to fabricate next generation nano-electronics devices. The pattern profile control of plasma etching with an accuracy of sub-nanometer must be achieved. To realize the etching process which achieves the problem, understanding of the etching mechanism and precise control of the process based on the real-time monitoring of internal plasma parameters such as etching species density, surface temperature of substrate, etc. are very important. For instance, it is known that the etched profiles of organic low dielectric (low-k) films are sensitive to the substrate temperature and density ratio of H and N atoms in the H2/N2 plasma [1]. In this study, we introduced a feedback control of actual substrate temperature and radical density ratio monitored in real time. And then the dependence of etch rates and profiles of organic films have been evaluated based on the substrate temperatures. In this study, organic low-k films were etched by a dual frequency capacitively coupled plasma employing the mixture of H2/N2 gases. A 100-MHz power was supplied to an upper electrode for plasma generation. The Si substrate was electrostatically chucked to a lower electrode biased by supplying a 2-MHz power. To investigate the effects of H and N radical on the etching profile of organic low-k films, absolute H and N atom densities were measured by vacuum ultraviolet absorption spectroscopy [2]. Moreover, using the optical fiber-type low-coherence interferometer [3], substrate temperature has been measured in real time during etching process. From the measurement results, the temperature raised rapidly just after plasma ignition and was gradually saturated. The temporal change of substrate temperature is a crucial issue to control of surface reactions of reactive species. Therefore, by the intervals of on-off of the plasma discharge, the substrate temperature was maintained within ${\pm}1.5^{\circ}C$ from the set value. As a result, the temperatures were kept within $3^{\circ}C$ during the etching process. Then, we etched organic films with line-and-space pattern using this system. The cross-sections of the organic films etched for 50 s with the substrate temperatures at $20^{\circ}C$ and $100^{\circ}C$ were observed by SEM. From the results, they were different in the sidewall profile. It suggests that the reactions on the sidewalls changed according to the substrate temperature. The precise substrate temperature control method with real-time temperature monitoring and intermittent plasma generation was suggested to contribute on realization of fine pattern etching.

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교양교육의 글로벌 역량 강화 방안 사례 연구: 비교과 영역을 중심으로 (Case Study on Global Competency Reinforcement of Liberal Arts Education: Focusing on Non-Curricular Areas)

  • 라미진
    • 항공우주의학회지
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    • 제31권1호
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    • pp.24-30
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    • 2021
  • Purpose: The purpose of this study is to consider ways to strengthen it through comparison and curriculum while recognizing the importance of global competencies in liberal arts education in universities. Methods: In order to explore ways to reinforce the sub-competence of global competencies, this study was conducted at a four-year university in Chungcheong-do for one year in 2019, such as 'Global Culture Talk', 'Global Travel', 'Global Nanta', and 'Making Global Friends'. Cases of comparison and application of educational programs were analyzed. The program was attended by the Department of Business Administration, Department of Aviation Service, Department of Design, Department of Manga Animation, Department of Broadcasting and Film, and foreign exchange students. The competency-centered curriculum not only has clear educational goals, but is also very advantageous in establishing a feedback system by measuring its performance. This study will assess the effectiveness of the education plan by diagnosing the change in competencies before and after the comparison and curriculum is operated. Results: The overall global competency has increased by 0.2 points compared to 2017. By subsector, it was found that the flexibility increased by 1.4 points. In the field of cross-cultural understanding, it rose 0.6 points, and in the field of global understanding, it rose 2.2 points, showing the largest increase in the sub-fields. Nevertheless, the field of global interest remains at a low level. This is considerably low compared to flexibility and ability to understand other cultures, and it is expected that measures for improvement should be continuously sought. Since the understanding of other cultures has already exceeded 60 points, it is expected that the global competency of the university will be strengthened if the level is consistently maintained and the emphasis is placed on enhancing flexibility and improving global understanding. Conclusion: The importance of strengthening global capabilities is steadily rising. Universities are also reorganizing the curriculum by analyzing the needs and satisfaction of education consumers to respond to this. The programs operated and analyzed in this study were also made as part of this effort. However, since there are various factors that affect global competency, it cannot be but admitted that it is not easy to gauge the change in competency with only a few programs and short-term efforts. However, if the efforts pursued by this study are accumulated and supplemented through feedback from a long-term perspective, it can be expected that there are not a lot of contributions to strengthening global competencies in liberal arts education.

이동 프로젝터 투사영역의 폐회로 기반 위치추적에 의한 인터랙티브 투사 (Interactive Projection by Closed-loop based Position Tracking of Projected Area for Portable Projector)

  • 박지영;이선민;김명희
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제37권1호
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    • pp.29-38
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    • 2010
  • 본 연구에서는 영상을 대형으로 디스플레이 함과 동시에 사용자가 보다 세밀하게 관찰하고자하는 관심영역을 이동 프로젝터로 투사함으로써 개선된 해상도와 밝기로 디스플레이 하는 인터랙티브 투사 기법을 제안한다. 사용자는 이동 프로젝터를 들고 움직이며 관심영역의 위치를 변경하게 되는데 이 때 적절히 투사영상을 업데이트하기 위해 폐회로(closed-loop) 기반 추적 방법을 제안한다. 먼저 대형 디스플레이 영상에 이동 프로젝터의 위치를 나타내는 표시자를 삽입하고 이를 이동 프로젝터에 부착된 카메라로 획득한 연속영상에서 추출한다. 표시자의 중심이 항상 카메라 영상의 중심과 일치하도록 하는 제약조건 하에서 이를 만족시키기 위해 대형 디스플레이 상에서 표시자의 위치를 지속적으로 업데이트 한다. 이렇게 계산된 표시자의 위치에 해당하는 사각형 영역을 이동 프로젝터가 투사하게 되며 이때 카메라와 이동 프로젝터 사이의 투사변환을 적용하여 와핑한다. 표시자 분할은 총 네 단계로 이루어지며 카메라 영상에 대해 HSI 기반 전처리, 직선 탐지, 사각형 조건 검사, 교차비(cross-ratio) 검사를 거쳐 최종 네 개의 코너점이 결정된다. 제안된 투사 기법을 적용하여 구현한 인터랙티브 투사 시스템은 약 24fps의 처리속도를 지원하며 사용자 평가 결과 높은 유용성을 나타냈다.

2차원 트러스 구조물에 대한 제어/구조 시스템의 동시최적설계 (Simultaneous Optimal Design of Control-Structure Systems for 2-D Truss Structure)

  • 박중현;김순호
    • 제어로봇시스템학회논문지
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    • 제7권10호
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    • pp.812-818
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    • 2001
  • This paper proposes an optimum design method of structural and control systems, taking a 2-D truss structure as an example. The structure is supposed to be subjected to initial static loads and disturbances. For the structure, a FEM model is formed, and using modal transformation, the equation of motion is transformed into that of modal coordinates in order to reduce the D.O.F. of the FEM model. The structure is controlled by an output feedback $H^$\infty$$ controller to suppress the effect of the disturbances. The design variables of the simultaneous optimal design of control-structure systems are the cross sectional areas of truss members. The structural objective function is the structural weight. The control objective function is the $H^$\infty$$ norm, that is, the performance index of control. The second structural objective function is the energy of the response related to the initial state, which is derived from the time integration of the quadratic form of the state in the closed-loop system. In a numerical example, simulations have been carried out. Through the consideration of structural weight and $H^$\infty$$ norm, an advantage of the simultaneous optimum design of structural and control systems is shown. Moreover, while the optimized performance index of control is almost kept, we can acquire better design of structural strength.

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간호학생을 위한 방문간호 비위관 관리교육 시뮬레이션 모듈 평가와 적용 효과: NLN Jeffries 시뮬레이션 이론 적용 (Evaluation and Application Effect of a Home Nasogastric Tube Feeding Simulation Module for Nursing Students: An Application of the NLN Jeffries Simulation Theory)

  • 백희정;이영란;이종은;이진화;김형선
    • 지역사회간호학회지
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    • 제28권3호
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    • pp.324-333
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    • 2017
  • Purpose: The purpose of this study was to develop a simulation module for teaching home health care and evaluate the applicability of the program to nursing students' practical training. Methods: The simulation module was developed based on the National League for Nursing Jeffries Simulation Theory. The theme of the developed scenario was teaching nasogastric tube feeding to the caregiver of patient with Parkinson disease. Participants were 61 nursing students who had learned tube feeding, and participated in the questionnaire survey after the simulation training. Results: The evaluation of simulation design showed the highest score on feedback/guided reflection, and was highly evaluated in the order of objectives/information, problem solving and fidelity. The educational practice of the simulation was highly evaluated in the order of active learning, high expectation and diversity of learning. The nursing students showed high satisfaction and self-confidence after the simulation education. Conclusion: We suggest that the developed simulation module can be applied to practical training for home health care. In the future, the change of self-efficacy, clinical judgment and performance ability of the students after the simulation education should be identified. Also, various simulation modules related to the community health nursing competencies should be continuously developed and verified.

훌라후프를 이용한 체중이동훈련이 뇌졸중 환자의 체중이동변화와 보행에 미치는 영향: 단면 예비연구 (The Effect of Weight-shift Training with Hula Hoop on Weight Shift Change and Gait in Stroke Patients: A Cross - Sectional Pilot Study)

  • 고연주;이한숙
    • 대한물리의학회지
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    • 제12권1호
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    • pp.9-14
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    • 2017
  • PURPOSE: To evaluate the effect of weight shift training with Hula Hoop on weight shift change and gait in stroke patients. METHODS: Ten stroke patients were enrolled in this study, and randomly divided into 2 groups. The study group underwent weight shift training with Hula Hoop, while the control group received general physical therapy that included weight shift training. All the studies were performed over a period of 4 weeks. Before and after the intervention, plantar pressure and performance in the 10 m walk test (10MWT) were assessed. Wilcoxon signed ranks test was used to compare the change from before to after the intervention in each group. The differences between the study and control groups were analyzed by using the Mann-Whitney test. RESULTS: After 4 weeks of intervention, the change in weight shift and performance in the 10MWT from before to after the experiment showed no statistical significance (p>.05). In addition, the comparison between the groups showed no significance in terms of weight-shift change, and performance in the 10MWT (p>.05). CONCLUSION: Although the difference was not statistically significant, the degree of improvement was similar to that attained with the conventional exercise treatment related to weight- shift training. During the course of the treatment, the patients received feedback through repeated training by themselves. Weight-shift training with Hula Hoop would be effective in improving the walking ability and weight-shifting on the paralyzed side of stroke patients. In the future, the effectiveness of this training would need to be validated.

Transmit Antenna Selection for Dual Polarized Channel Using Singular Value Decision

  • Lee Sang-yub;Mun Cheol;Yook Jong-gwan
    • 한국통신학회논문지
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    • 제30권9A호
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    • pp.788-794
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    • 2005
  • In this paper, we focus on the potential of dual polarized antennas in mobile system. thus, this paper designs exact dual polarized channel with Spatial Channel Model (SCM) and investigates the performance for certain environment. Using proposed the channel model; we know estimates of the channel capacity as a function of cross polarization discrimination (XPD) and spatial fading correlation. It is important that the MIMO channel matrix consists of Kronecker product dividable spatial and polarized channel. Through the channel characteristics, we propose an algorithm for the adaptation of transmit antenna configuration to time varying propagation environments. The optimal active transmit antenna subset is determined with equal power allocated to the active transmit antennas, assuming no feedback information on types of the selected antennas. We first consider a heuristic decision strategy in which the optimal active transmit antenna subset and its system capacity are determined such that the transmission data rate is maximized among all possible types. This paper then proposes singular values decision procedure consisting of Kronecker product with spatial and polarize channel. This method of singular value decision, which the first channel environments is determined using singular values of spatial channel part which is made of environment parameters and distance between antennas. level of correlation. Then we will select antenna which have various polarization type. After spatial channel structure is decided, we contact polarization types which have considerable cases It is note that the proposed algorithms and analysis of dual polarized channel using SCM (Spatial Channel Model) optimize channel capacity and reduce the number of transmit antenna selection compare to heuristic method which has considerable 100 cases.

국·내외 초등학교 융합 과학 교육 프로그램 탐색 - 한국, 미국, 영국을 중심으로 - (Exploring Domestic and International Elementary School Convergence Science Education Program - Korea, the U.S., and the U.K. -)

  • 나상훈;권난주
    • 한국초등과학교육학회지:초등과학교육
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    • 제33권2호
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    • pp.231-241
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    • 2014
  • This study is subject to compare the STEAM and the STEM education of Korea, the U.K., and the U.S. to find their differences and similarities, as well as the implications in implementing the STEAM education in Korea. In order to accomplish this, the educational objectives, contents and topics, teaching and learning methods, subjects and timing for education, and convergence curriculum were compared; also, after choosing the representative program of each country, a cross-comparative analysis was done for the teaching and learning method distribution ratio, content element distribution ratio, program distribution ratio, STEAM domain ratio, curriculum structure and domain ratio, frequency of inquiry process, basic inquiry, integrated inquiry frequency, hourly basic inquiry, and integrated inquiry process. As a result, it was possible to obtain 77 programs, a total of 656 class hours of Korea, 65 programs and 846 class hours of the U.S., and 75 programs and 774 class hours of the U.K. The results are as follows: Korea's STEAM and the U.K. and the U.S.' STEM all include science, technology, engineering, arts, and mathematics, but in terms of frequency, Korea's STEAM has higher figure in arts. However, the U.K. and the U.S. have higher frequency of debate and discussion, and there were many cases of a student, after receiving feedback from other students, modifying the work.

Analysis of Cross Sectional Ease Values for Fit Analysis from 3D Body Scan Data Taken in Working Positions

  • Nam, Jin-Hee;Branson, Donna H.;Ashdown, Susan P.;Cao, Huantian;Carnrite, Erica
    • International Journal of Human Ecology
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    • 제12권1호
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    • pp.87-99
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    • 2011
  • Purpose- The purpose of this study was to compare the fit of two prototype liquid cooled vests using a 3D body scanner and accompanying software. The objectives of this study were to obtain quantitative measurements of ease values, and to use these data to evaluate the fit of two cooling vests in active positions and to develop methodological protocol to resolve alignment issues between the scans using software designed for the alignment of 3D objects. Design/methodology/approach- Garment treatments and body positions were two independent variables with three levels each. Quantitative dataset were dependent variables, and were manipulated in 3x3 factorial designs with repeated measures. Scan images from eight subjects were used and ease values were obtained to compare the fit. Two different types of analyses were conducted in order to compare the fit using t-test; those were radial mean distance value analysis and radial distance distribution rate analysis. Findings- Overall prototype II achieved a closer fit than prototype I with both analyses. These were consistent results with findings from a previous study that used a different approach for evaluation. Research limitations/implications- The main findings can be used as practical feedback for prototype modification/selection in the design process, making use of 3D body scanner as an evaluation tool. Originality/value- Methodological protocols that were devised to eliminate potential sources of errors can contribute to application of data from 3D body scanners.