• Title/Summary/Keyword: Output feedback system

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A Study on Method for Promoting Interaction in L2 Classroom Using Clickers (Clicker를 활용한 한국어 교실 상호 작용 증진 방안 연구)

  • Ryoo, Hye Jin
    • Journal of Korean language education
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    • v.25 no.1
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    • pp.53-82
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    • 2014
  • This study aims to find the method to promote interaction in L2 classrooms. Active interaction between learner-to-learner and learner-to-teacher in L2 classroom plays an important role in language acquisition. In light of this, L2 classroom would benefit with the help of learning tools such as Clickers which helps learners to express their level of understanding during the process of learning itself. This is because the anonymity of Clickers allows learners to express their needs without the social risks associated with speaking up in the class. It allows for an evaluative feedback loop where both learners and teachers understand the level of progress of the learners, better enabling classrooms to adapt to the learners' needs. Eventually this tool promotes participation from learners, This is in turn, believed to be effective in fostering classroom interaction, allowing learning to take place in a more comfortable yet vibrant way. This study is finalized by presenting the result of an experiment conducted to verify the effectiveness of this approach when teaching pragmatic aspect of the Korean expressions with similar semantic functions. As a result of the research, the learning achievement of learners in the experimental group was found higher than the learners' in a control group. Analyzing the data collected from a questionnaire given to the learners, the study presented data suggesting that this approach increased the scope of interactivity in the classroom, thus enhancing more active participation among learners. This active participation in turn led to a marked improvement in their communicative abilities.

The Design of Smart Antenna Structures for RF Repeater (이동통신 중계기용 스마트 안테나 구조 설계)

  • Cho, Dae-Young;Kim, Kye-Won;Lee, Seung-Goo;Kim, Min-Sang;Kim, Kil-Yung;Park, Byeong-Hoon;Ko, Hak-Lim
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.2
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    • pp.110-116
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    • 2013
  • The amplification rate of a RF repeater is limited by the feedbacked signals from the same repeater. And an ICS (Interference Cancellation System) repeater has been developed to remove the feedbacked signals. The ICS repeater estimates the amplitudes and the phases of the feedbacked signals and removes the estimated feedback signals from the received input signal of the repeater. However, it requires lots of hardware complexity and this leads to the increase the cost of the repeater. Moreover, the ICS repeater can not solve the pilot pollution problems. To solve these problems, we have studied the implementation and adaptation of smart antenna system for RF repeaters. We have designed a smart antenna system with a switching beam structure in order to reduce the hardware and computational complexity. After analyzing the proposed smart antenna system, we found out that the amplification rate of the proposed repeater increases 23dB compare to the amplification rate of ICS repeater and the output SINR increases 6dB compare to the ICS repeater.

Development of Indentation Training System for Pulse Diagnosis (맥진 가압 트레이닝 시스템 개발)

  • Lee, Jeon;Lee, Yu-Jung;Jeon, Young-Ju;Woo, Young-Jae;Kim, Jong-Yeol
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.6
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    • pp.117-122
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    • 2008
  • Although the pulse diagnosis is the one of the most important diagnostic process to traditional medical doctors, there is no proper communication tool between experts and trainees. In this paper, we have developed a indentation training system which consists of a hardware measuring indent pressure on artificial arm quantitatively and a software providing a indentation training program. The hardware for measurement of indent pressure profile includes 3 load cells embedded in the artificial arm, signal amplification part and digitization part, NI-USB 6009 with 200Hz sampling rate. For setting up a relationship table between weights and output voltages, 8 standard weights were used. To evaluate this hardware, 3 oriental medical specialists were involved and their indent pressure profile were recorded three times respectively. From these, it was found that pulse diagnosis process could be divided into 3 periods and the maximum load were $500g{\cdot}f$ approximately while doctors perform a pulse diagnosis. The indentation training program was implemented with LabView and designed to monitor the differences between the pressure profile of a expert and that of a trainee so to offer some visual feedback to the trainee. Also, this program could provide the trends of training performances. With this developed system, the education of pulse diagnosis is expected to be more quantitative and effective.

Development of the Information Delivery System for the Home Nursing Service (가정간호사업 운용을 위한 정보전달체계 개발 I (가정간호 데이터베이스 구축과 뇌졸중 환자의 가정간호 전산개발))

  • Park, J.H;Kim, M.J;Hong, K.J;Han, K.J;Park, S.A;Yung, S.N;Lee, I.S;Joh, H.;Bang, K.S
    • Journal of Home Health Care Nursing
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    • v.4
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    • pp.5-22
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    • 1997
  • The purpose of the study was to development an information delivery system for the home nursing service, to demonstrate and to evaluate the efficiency of it. The period of research conduct was from September 1996 to August 31, 1997. At the 1st stage to achieve the purpose, Firstly Assessment tool for the patients with cerebral vascular disease who have the first priority of HNS among the patients with various health problems at home was developed through literature review. Secondly, after identification of patient nursing problem by the home care nurse with the assessment tool, the patient's classification system developed by Park (1988) that was 128 nursing activities under 6 categories was used to identify the home care nurse's activities of the patient with CAV at home. The research team had several workshops with 5 clinical nurse experts to refine it. At last 110 nursing activities under 11 categories for the patients with CVA were derived. At the second stage, algorithms were developed to connect 110 nursing activities with the patient nursing problems identified by assessment tool. The computerizing process of the algorithms is as follows: These algorithms are realized with the computer program by use of the software engineering technique. The development is made by the prototyping method, which is the requirement analysis of the software specifications. The basic features of the usability, compatibility, adaptability and maintainability are taken into consideration. Particular emphasis is given to the efficient construction of the database. To enhance the database efficiency and to establish the structural cohesion, the data field is categorized with the weight of relevance to the particular disease. This approach permits the easy adaptability when numerous diseases are applied in the future. In paralleled with this, the expandability and maintainability is stressed through out the program development, which leads to the modular concept. However since the disease to be applied is increased in number as the project progress and since they are interrelated and coupled each other, the expand ability as well as maintainability should be considered with a big priority. Furthermore, since the system is to be synthesized with other medical systems in the future, these properties are very important. The prototype developed in this project is to be evaluated through the stage of system testing. There are various evaluation metrics such as cohesion, coupling and adaptability so on. But unfortunately, direct measurement of these metrics are very difficult, and accordingly, analytical and quantitative evaluations are almost impossible. Therefore, instead of the analytical evaluation, the experimental evaluation is to be applied through the test run by various users. This system testing will provide the viewpoint analysis of the user's level, and the detail and additional requirement specifications arising from user's real situation will be feedback into the system modeling. Also. the degree of freedom of the input and output will be improved, and the hardware limitation will be investigated. Upon the refining, the prototype system will be used as a design template. and will be used to develop the more extensive system. In detail. the relevant modules will be developed for the various diseases, and the module will be integrated by the macroscopic design process focusing on the inter modularity, generality of the database. and compatibility with other systems. The Home care Evaluation System is comprised of three main modules of : (1) General information on a patient, (2) General health status of a patient, and (3) Cerebrovascular disease patient. The general health status module has five sub modules of physical measurement, vitality, nursing, pharmaceutical description and emotional/cognition ability. The CVA patient module is divided into ten sub modules such as subjective sense, consciousness, memory and language pattern so on. The typical sub modules are described in appendix 3.

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Spatial Multiplexing Using Open-Loop Precoding in Maritime Communication Environment with Channel Correlation and LOS (채널 상관 및 직접파가 존재하는 해상 통신 환경에서 개루프 프리코딩 기반의 공간다중화 전송 기법)

  • Jang, Jungyup;Lee, Seong Ro;Kim, Dong Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.7
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    • pp.1397-1404
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    • 2015
  • Recently, high data rate transmission is required in maritime communication. In this paper, we consider multiple input multiple output (MIMO) spatial multiplexing (SM). However, the performance of SM is severly degraded due to spatial channel correlation and line-of-sight (LOS) component. In the maritime communication, the MIMO channel correlation and LOS are critical due to the lack of scatteres around the transmitter and/or the receiver. When the feedback of channel information is available, precoding can enhance the error performance by exploiting the channel information. However, it is difficult to derive closed-form solution considering both the correlation and LOS. In this paper, we present open-loop precoding-based spatial multiplexing transmission method by showing that the effect of performance for the correlation and LOS. It is shown that the open-loop precoding can mitigate the performance degradation due to the LOS as well as the correlation. Consequently, we expect that the proposed open-loop precoding can be adopted to the maritime communication system.

Performance Analysis of the Channel Equalizers for Partial Response Channels (부분 응답 채널을 위한 채널 등화기들의 성능 분석에 관한 연구)

  • Lee, Sang-Kyung;Lee, Jae-Chon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.8A
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    • pp.739-752
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    • 2002
  • Recently, to utilize the limited bandwidth effectively, the concept of partial response (PR) signaling has widely been adopted in both the high-speed data transmission and high-density digital recording/playback systems such as digital microwave, digital subscriber loops, hard disk drives, digital VCR's and digital versatile recordable disks and so on. This paper is concerned with adaptive equalization of partial response channels particularly for the magnetic recording channels. Specifically we study how the PR channel equalizers work for different choices of desired or reference signals used for adjusting the equalizer weights. In doing so, we consider three different configurations that are actually implemented in the commercial products mentioned above. First of all, we show how to compute the theoretical values of the optimum Wiener solutions derived by minimizing the mean-squared error (MSE) at the equalizer output. Noting that this equalizer MSE measure cannot be used to fairly compare the three configurations, we propose to use the data MSE that is computer just before the final detector for the underlying PR system. We also express the data MSE in terms of the channel impulse response values, source data power and additive noise power, thereby making it possible to compare the performance of the configurations under study. The results of extensive computer simulation indicate that our theoretical derivation is correct with high precision. Comparing the three configurations, it also turns out that one of the three configurations needs to be further improved in performance although it has an apparent advantage over the others in terms of memory size when implemented using RAM's for the decision feedback part.

Fiber-optic Mach-Zehnder Interferometer for the Detection of Small AC Magnetic Field (미소 교류 자기장 측정을 위한 Mach-Zehnder 광섬유 간섭계 자기센서 특성분석)

  • 김대연;안준태;공홍진;김병윤
    • Korean Journal of Optics and Photonics
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    • v.2 no.3
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    • pp.139-148
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    • 1991
  • A fiber-optic magnetic sensor system for the detection of small ac magnetic field(200Hz-2 kHz) was constructed. Magnetic field sensing part was fabricated by bonding a section of optical fiber to amorphous metallic glass(2605SC) having large magnetostriction effect. And with the directional coupler, all fiber type Mach-Zehnder interferometer was constructed to measure the variation of the external magnetic field by translating it into the optical phase shift in the interferometer. The signal fading problem of the interferometer, which is due to random phase drifts originated from the environment, i.e., temperature fluctuation, vibrations, etc., was elliminated by feedback phase compensation. This allows the sensitivity to be maintained at the maximum by keeping the interferometer in quadrature phase condition. The frequency response of metallic glass was found to be nearly flat in the range of 90 Hz-2 kHz and dc bias field for the maximum ac response was 3.5 Oe. The interferometer output showed good linearity over the range $\pm$0.5 Oe. For 1 kHz ac magnetic field the scale factor S and the minimum detectable magnetic field were measured to be 8.0 rad/Oe and $3X10^{-6} Oe/\sqrt{Hz}$at 1 Hz detection bandwidth respectively.

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A Study on the Characteristics and Evaluation of the Policy in Japan's recent Reform of Education - Focus on the MEXT and CCE - (일본의 최근 교육개혁 정책의 특징과 평가 - 문부과학성과 중앙교육심의회를 중심으로 -)

  • Ko, Jeon
    • Korean Journal of Comparative Education
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    • v.26 no.4
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    • pp.173-198
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    • 2016
  • The purpose of this study is to analyze the characteristics of Educational Reforms Policy in lately Japan and to evaluate it. Especially focus on the activities of the [MEXT; Ministry of Education, Culture, Sports, Science and Technology] and [CCE;The Central Council for Education] This article composed of five chapters; Implication and problem situation, History of the Japanese educational reforms, the characteristics in the site of process of educational reforms policy, evaluation on the main policies, and Conclusion(contain the suggestion for Korea). The method of study composed of the literature search and interview. The System Analysis[input-process-output-feedback] is used as a model of the analyze the characteristics of educational reforms policy. By the new Basic Act on Education, the principles of educational administration is changed. Education administration shall be carried out in a fair and proper manner through appropriate role sharing and cooperation between the national and local governments(Article 16). As a conclusion, The initiative in the establishment of educational reform plans has gone over to the cabinet side from MEXT. And evaluate the five policies. That is Japan's Basic Plan for the Promotion of Education, The new Basic Act on Education(enacted on 2006), Provincial Governor's (Tokyo & Oska) Educational Reform Plan, Reform plan of the Boards of Education, and Improvement Policy of the Quality of Teachers.

Design and Implementation of a Similarity based Plant Disease Image Retrieval using Combined Descriptors and Inverse Proportion of Image Volumes (Descriptor 조합 및 동일 병명 이미지 수량 역비율 가중치를 적용한 유사도 기반 작물 질병 검색 기술 설계 및 구현)

  • Lim, Hye Jin;Jeong, Da Woon;Yoo, Seong Joon;Gu, Yeong Hyeon;Park, Jong Han
    • The Journal of Korean Institute of Next Generation Computing
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    • v.14 no.6
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    • pp.30-43
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    • 2018
  • Many studies have been carried out to retrieve images using colors, shapes, and textures which are characteristic of images. In addition, there is also progress in research related to the disease images of the crop. In this paper, to be a help to identify the disease occurred in crops grown in the agricultural field, we propose a similarity-based crop disease search system using the diseases image of horticulture crops. The proposed system improves the similarity retrieval performance compared to existing ones through the combination descriptor without using a single descriptor and applied the weight based calculation method to provide users with highly readable similarity search results. In this paper, a total of 13 Descriptors were used in combination. We used to retrieval of disease of six crops using a combination Descriptor, and a combination Descriptor with the highest average accuracy for each crop was selected as a combination Descriptor for the crop. The retrieved result were expressed as a percentage using the calculation method based on the ratio of disease names, and calculation method based on the weight. The calculation method based on the ratio of disease name has a problem in that number of images used in the query image and similarity search was output in a first order. To solve this problem, we used a calculation method based on weight. We applied the test image of each disease name to each of the two calculation methods to measure the classification performance of the retrieval results. We compared averages of retrieval performance for two calculation method for each crop. In cases of red pepper and apple, the performance of the calculation method based on the ratio of disease names was about 11.89% on average higher than that of the calculation method based on weight, respectively. In cases of chrysanthemum, strawberry, pear, and grape, the performance of the calculation method based on the weight was about 20.34% on average higher than that of the calculation method based on the ratio of disease names, respectively. In addition, the system proposed in this paper, UI/UX was configured conveniently via the feedback of actual users. Each system screen has a title and a description of the screen at the top, and was configured to display a user to conveniently view the information on the disease. The information of the disease searched based on the calculation method proposed above displays images and disease names of similar diseases. The system's environment is implemented for use with a web browser based on a pc environment and a web browser based on a mobile device environment.

Changes of Minute Blood Flow in the Large Vessels during Orthostasis and Antiorthostasis, before and after Atropine Administration (체위변화가 두부 및 하지의 분시혈류량에 미치는 영향)

  • Park, Won-Kyun;Chae, E-Up
    • The Korean Journal of Physiology
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    • v.19 no.2
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    • pp.139-153
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    • 1985
  • The passive tilt has been performed to study the orthostasis on the cardiovascular system. The orthostasis due to upright tilt was demonstrated as follows: the venous return, cardiac output and systemic arteiral blood pressure were decreased, whereas there was concomitant increase of heart rate, through the negative feedback mediated by such as the baroreceptor . Previous investigators have suggested that the tolerance to the orthostasis could he increased by blocking the cholinergic fiber with atropine which prevented vasodilation and bradycardia through the vasovagal reflex during the orthostasis. However, this hypothesis has not been clearly understood. This study was attempted to clarify the effect of atropine on the tolerance of the cardiovascular system to the upright and head-down tilt, and to investigate the change of the blood flow through head and lower leg with Electromagnetic flowmeter in both tilts before and after atropine state. Fourteen anesthetized dogs of $10{\sim}14kg$ were examined by tilting from supine position to $+77^{\circ}$ upright position (orthostasis), and then to $-90^{\circ}$ head-down position (antiorthostasis) for 10 minutes on each test. And the same course was taken 20 minutes after intravenous administration of 0.5mg atropine. The measurements were made of the blood flow(ml/min.) on the carotid artery, external jugular vein, femoral artery and femoral vein. At the same time pH, $PCO_2$, $PO_2$ and hematocrit (Hct) of the arterial and venous blood, and heart rate(HR) and respiratory rate (RR) were measured. The measurements obtained from upright and head-down tilt were compared with those from supine position. The results obtained are as follows: In upright tilt, the blood flow both on the artery and the vein through head and lower leg were decreased, however the decrement of blood flow through the head was greater than the lower leg And the atropine attenuated the decrement of the blood flow on the carotid artery, but not on the vessels of the lower leg. HR was moderately increased in upright tilt, but slightly in head-down tilt. The percent change of HR after the atropine administration was smaller than that before the atropine state in both upright and head-down tilts. Before the atropine state, RR was decreased in upright tilt, whereas increased in head-down tilt. However after the atropine state, the percent change of RR was smaller than that of before the atropine state in both upright and head-down tilts. In upright tilt, venous $PCO_2$ was increased, but arterial $PO_2$ and venous $PO_2$ were slightly decreased. Hct was increased in both upright and head-down tilts. The findings of blood $PCO_2$, $PO_2$ and Hct were not interferred by the atropine. In conclusion, 1;he administration of atropine is somewhat effective on improving the cardiovascular tolerance to postural changes. Thus, atropine attenuates the severe diminution of the blood flow to the head during orthostasis, and also reduces the changes of HR and RR in both orthostasis and antiorthostasis.

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