• Title/Summary/Keyword: active feedback

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The Effects of Craniocervical Flexion Exercise on Deep Cervical Flexor Muscle Thickness and Gait for Children with Hemiplegic Cerebral Palsy (머리-목 굽힘 운동이 편측 뇌성마비 환자의 깊은 목 굽힘근의 두께와 보행에 미치는 영향)

  • Yun, Changkyo;Kim, HyunSung
    • Journal of The Korean Society of Integrative Medicine
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    • v.6 no.1
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    • pp.99-105
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    • 2018
  • Purpose : The purpose of this study was to evaluate the effect of craniocervical flexion exercise on deep cervical flexor thickness and gait in children with hemiplegic cerebral palsy. Methods : Twelve children with hemiplegic cerebral palsy were recruited for this study. All subjects performed active craniocervical flexion exercise 3times a week over the course of 6weeks. using a pressure bio feedback unit. Ultrasonography was used to assess deep cervical flexor thickness, and a 10m walking test was used to assess gait function. For the statistical analysis, a paired t-test was used to compare the differences pre- and post-value. SPSS Statistics version 20.0 was used for statistical analysis, and statistical significance was defined as a p-value less than 0.05. Result : The results of this study indicate that children with hemiplegic cerebral palsy experienced statistically significant positive changes in both deep cervical flexor thickness (p<.05). and gait(p<.05) following the intervention. Conclusion : In conclusion, craniocervical flexion exercise can positively affect deep cervical flexor thickness in children with hemiplegic cerebral palsy, which in turn positively affects gait.

Robust decentralized control of structures using the LMI Hcontroller with uncertainties

  • Raji, Roya;Hadidi, Ali;Ghaffarzadeh, Hosein;Safari, Amin
    • Smart Structures and Systems
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    • v.22 no.5
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    • pp.547-560
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    • 2018
  • This paper investigates the operation of the $H_{\infty}$ static output-feedback controller to reduce dynamic responses under seismic excitation on the five-story and benchmark 20 story building with parametric uncertainties. Linear matrix inequality (LMI) control theory is applied in this system and then to achieve the desired LMI formulations, some transformations of the LMI variables is used. Conversely uncertainties due to material properties, environmental loads such as earthquake and wind hazards make the uncertain system. This problem and its effects are studied in this research. Also to decrease the transition of large amount of data between sensors and controller, avoiding the disruption of whole control system and economy problems, the operation of the decentralized controllers is investigated in this paper. For this purpose the comparison between the performance of the centralized, fully decentralized and partial decentralized controllers in uncoupled and coupled cases is performed. Also, the effect of the changing the number of stories in substructures is considered. Based on the numerical results, the used control algorithm is very robust against the parametric uncertainties and structural responses are decreased considerably in all the control cases but partial decentralized controller in coupled form gets the closest results to the centralized case. The results indicate the high applicability of the used control algorithm in the tall shear buildings to reduce the structural responses and its robustness against the uncertainties.

IPS-Mode Dynamic LCD-TV Realization with Low Black Luminance and High Contrast by Adaptive Dynamic Image Control Technology

  • Oh, E.Y.;Baik, S.H.;Sohn, M.H.;Kim, K.D.;Hong, H.J.;Bang, J.Y.;Kwon, K.J.;Kim, M.H.;Jang, H.;Yoon, J.K.;Chung, I.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.799-802
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    • 2004
  • In this paper, the active backlight control technology with data processing algorithm was developed in order to improve image quality for IPS-mode LCD-TV applications. The image blinking problem caused by repeatedly abrupt change of the backlight luminance was solved by algorithms-Fba(Flexible Boundary algorithm) and Cfa(Cumulative Feedback algorithm)-and the optimized number and space of backlight dimming steps based on perception. In the IPS-mode 42" TFT-LCD panel, the dynamic contrast ratio can be more than twice the typical level by means of lower block luminance and higher white luminance. Additionally, Power consumption and LCD temperature was decreased.

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Proving the Evolution of Relativistic Jet of Radio-Loud AGN, OVV 1633+382

  • Ro, Hyunwook;Sohn, Bong Won;Chung, Aeree;Krichbaum, Thomas P.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.37.1-37.1
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    • 2015
  • It is suggested that relativistic jets associated with active galactic nuclei (AGNs) can have great impacts on the evolution of the host galaxy. However, the physical properties of AGN jets including the formation mechanism are not well known to date, and hence the AGN feedback on the host galaxy is yet poorly understood. OVV 1633+382 as a highly variable AGN source (a.k.a. blazer) with a compact core and very well developed jet components is an excellent laboratory to study the jet formation mechanism of radio-loud AGN. Near 2002, a major flare was reported at mm wavelength with a dramatic increase of the flux, which is likely to be followed by a dense and bright outflow. In order to probe the evolution of the innermost region of this radio-loud AGN, we have monitored using the Very Large Baseline Array (VLBA) and the Effelsberg 100m single-dish radio telescope in 12 epochs from 2002 and 2005. The observations were conducted at 22, 43 and 86 GHz in full polarization mode. In this work, we present the intensity and spectral index maps at 22 and 43 GHz from our monitoring observations. We probe the kinematics and geometry of individual jet components to discuss the evolution of the jet.

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Effects of Guideway's Vibration Characteristics on Dynamics of a Maglev Vehicle (가이드웨이 진동 특성이 자기부상열차 동특성에 미치는 영향)

  • Han, Hyung-Suk;Yim, Bong-Hyuk;Lee, Nam-Jin;Hur, Young-Chul;Kwon, Jung-Il
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.3
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    • pp.299-306
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    • 2008
  • The electromagnet in Maglev vehicles controls the voltage in its winding to maintain the air gap, a clearance between the electromagnet and guideway, within an allowable deviation, with strongly interacting with the flexible guideway. Thus, the vibration characteristics of guideway plays important role in dynamics of Maglev vehicles using electromagnet as an active suspension system. The effects of the guideway's vibrational characteristics on dynamics of the Maglev vehicle UTM-01 are analyzed. The coupled equations of motion of the vehicle/guideway with 3 DOFs are derived. Eigenvalues are calculated and frequency response analysis is also performed for a clear understanding of the dynamic characteristics due to guideway vibration characteristics. To verify the results, tests of the urban Mgalev vehicle UTM-02 are carried out. It is recommended that the natural frequency of the guideway be minimized and its damping ratio in the Maglev vehicle with a 5-states feedback control law as a levitation control law.

Control of Combustion Instabilities in a Gas Turbine Combustors Through Secondary Fuel Injection (가스터빈 연소기내 2차연료분사에 의한 연소 불안정성의 제어)

  • Jeon, C.H.;Santavicca, Domenic A.
    • Journal of the Korean Society of Combustion
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    • v.3 no.1
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    • pp.59-69
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    • 1998
  • The results of study on the active control of naturally occurring combustion oscillations with a single dominant frequency in an atmospheric dump combustor are presented. Control was achieved by an oscillatory infection of secondary fuel at the dump plane. A high speed solenoid valve with a maximum frequency of 250Hz was used as the actuator and a sound level meter, located at the combustor exit, measured the pressure fluctuations which served as the feedback signal for the control loop. Instability characteristics were mapped over a range of mean mixing section velocities from 6.7 m/s-9.3 m/s and with three mixing conditions. Different fuel/air mixing conditions were investigated by introducing varying percentages of primary fuel at two locations, one at the entrance to the mixing section and one 6 mixing tube diameters upstream of the dump plane. Control studies were conducted at a mean velocity of 9.3 m/s, with an air temperature of $415^{\circ}C$, and from flame blowout to the stoichiometric condition.

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The Student Internship Experience (의과대학 학생인턴제의 운영 일례 연구)

  • Choi, Son-Hwan
    • Korean Medical Education Review
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    • v.17 no.1
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    • pp.26-32
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    • 2015
  • Recently, the student internship has been introduced in medical schools as a way of preparing students with training experience and medical knowledge by performing clinical practice. This study discusses student internship management and ways to operate the internship effectively. Catholic University of Daegu School of Medicine has set up a 6-week internship program for fourth-year undergraduate students. In most of the sections, students have shown their satisfaction, particularly when they have received appropriate feedback and attention from their professors. The students found that performing the evaluation and treatment of patients and individual chart recording were informative and helpful. However, they felt a lack of basic knowledge and clinical skills and had difficulty in understanding their roles and in time management. The success of an internship depends on the passion and interest that professors show for their students along with active support from the other faculty and thoughtful consideration of patients and all their friends and family members. In addition, with growing awareness of the need for the student internship, it is necessary that the school executive provide financial and administrative support to the faculty and staff, clarify roles and the work needed to perform the tasks, ensure substantiality of the individual program with professors or departments, provide enough preliminary courses, and monitor outcomes and reflection.

Suggestion for the development model of next generation e-learning contents drawn from the principle of web progress (웹의 진화 원칙에서 도출해 낸 차세대 e-Learning 콘텐츠의 발전 모델 제안)

  • Bang, mihyang
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.719-723
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    • 2007
  • It is very active that existing companies of providing e-Learning contents try to differentiate themselves through a business model based on Web 2.0. For instance, Etoos, online education website (www.etoos.com) run by SK Communications has made more space where students can participate in the Web 2.0 era and overhauled its website completely, turning into an open-ended one, which strengthens learning and fun in 2007. This study is to analyze the present state of e-Learning contents with representative e-learning sites for middle and high school students, to find that the development direction for next generation e-Learning lies in developing contents focusing on learners that can get effective feedback and drawing collective intelligence grounded on the essence of Web 2.0, and to suggest 'the project to form virtual private tutor community in e-Learning contents.'

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A Study on the Using Product Prototype as a Usability Tasting Contents through WWW (웹상에서 프로토타입의 사용성 평가 콘텐츠 활용에 대한 연구)

  • 이상화
    • The Journal of the Korea Contents Association
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    • v.1 no.1
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    • pp.100-108
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    • 2001
  • To develope more competitive products, lots of attentions are paid to the study of user participation in the process of product design. In this circumstance, the user participation at a usability testing phase is relatively active. However, the usability testing in the controlled laboratory has some drawbacks. for stance, It needs a lot of money, efforts, and time. Most of all, it is difficult to collect a vast range of data and gain a fast feedback Recently, to overcome these difficulties mentioned above, international usability testing has been applied. Especially, usability testing Contents through Internet is considered most effective one. Because it has a lot of merits such as easiness of collecting remote user, simplicity of collecting data, cost effectiveness and so on. With these merits, this study takes advantage of using a WWW to carry out usability test and to collect remote usability data. And a website was development for posting computer simulated product so that the remote users can test its usability through internet.

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Analysis of the spontaneous emission spectrum of a multisection DFB structure device (다중 구역 DFB 구조 소자의 자연 방출 스펙트럼에 관한 해석)

  • 정기숙;김부균;이봉영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.7
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    • pp.230-244
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    • 1996
  • We derive analytic expressions for the spontaneous emission spectrum (SES) of a multisection distributed feedback (DFB) structure device employing complex coupled gratings including the effects of both facets reflections. The multisection DFB structure device used in the analysis is a general model which allows the independent phase of a grating in each section, and the sections without gratings. The expressions are the same as those derived by makino and glinski in case the gratings are index coupled and the phase of a grating in each section, ${\varphi}_k$ is '0' which means the phase of gratings in the device is ocntinuous. The expressions for the SES of a phase-shift-controlled (PSC) DFB structure device using tunable devices are derived from the general expressions. The number of parametes of the expressions is reduced by using the parameter of effective phase shift defined by the sum of the phase shift in a PSC region and the difference of the phase of a grating in each active region. Equations showing the effect of both facets reflections and the effective phase shift on the SES are derived. The validaty of the equations is verified by computer simultions. Computer simulation results also show the possibility of evaluating the structure parametes of the device from its SES.

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