• 제목/요약/키워드: cut-off function

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파킨슨병 환자의 인구학적.임상적 특성에 따른 우울, 일상생활 수행능력 및 인지기능 (Influence of Clinical and Demographical Variables on Depression, Instrumental Activities of Daily Living, and Cognitive Function in Patients with Parkinson's Disease)

  • 송경애;최동원;박혜자
    • 기본간호학회지
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    • 제13권2호
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    • pp.249-256
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    • 2006
  • Purpose: To investigate the influence of clinical and demographical variables on depression, instrumental activities of daily living (IADL), and cognitive function in patients with Parkinson's disease. Method: Using a structured questionnaire data were collected from 100 participants registered in the neurology department of C university hospital. Duration and stage of disease, fall history, vision impairment, duration and quality of sleep, orthostatic hypotension, ambulation impairment, and use of walking aid were included in clinical variables. Depression, IADL, and cognitive function were assessed using Kee's GDSSF-K, Cho's scale, and K-MMSE. Collected data were analyzed using the SAS program. Results: The depression score for the participants was 7.78, higher than cut-off score(5). Participants who were male, living with spouse, above high school education, high economic status, with no vision impairment, and no ambulation impairment revealed high cognitive scores. Average IADL score were significantly higher for participants who were male, who had high economic status, low stage of disease, and no ambulation impairment. Depression IADL & cognitive function scores were significantly different according to ambulation impairment. Scores for ADL and cognitive function were positively correlated. Conclusion: It is recommended that make programs for patients with Parkinson's disease, clinical and demographic variables should be considered according to their individual needs.

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변형된 창함수를 사용한 FIR 디지털 필터에 관한 연구 (A Study on the FIR Digital Filter using Modified Window Function)

  • 강경덕;배상범;김남호;류지구
    • 융합신호처리학회논문지
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    • 제4권1호
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    • pp.49-55
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    • 2003
  • 현대산업사회의 발전에 따라 신호처리 분야 중 디지털필터의 사용은 급격히 증가하고 있으며, 특히 디지털 영상처리, 디지털 음성처리, CATV 및 각종 통신 분야 등에서 카메라의 Detail processor, Y/C separator, Ghost제거 필터, 표준변환기(NTSC-PAL), Noise reducer 등으로 많이 사용되고 있다. 이러한 디지털필터에는 일반적으로 IIR(infinite impulse response)과 FIR(finite impulse response) 필터가 있으며, 본 논문에서는 구현이 용이하고 선형위상특성을 갖는 FIR 디지털필터를 설계하였다. FIR 디지털필터 설계에 있어서 통과대역의 차단주파수 부근에서 깁스(gibbs) 현상에 의해 생긴 리플을 완화하기 위해 window함수를 사용한다. 그러나, 기존의 window는 고정된 값으로 되어 있으므로 설계목적에 적합한 window함수를 선택함에 있어 다소 문제점이 있다. 따라서, 본 논문에서는 설계목적에 따라 서 융통성있게 선택이 가능한 파라메터를 부가한 변형된 Hanning window를 설계하였으며, 타당성을 입증하기 위해 디지털필터를 설계하여 기존의 Hamming, Hanning, Blackman, Kaiser window와 비교하였으며, 판단기준으로 peak side-lobe와 천이특성 등을 사용하였다.

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만성 편마비 뇌졸중 환자의 인지기능이 신체기능 수준 및 기능적 활동에 미치는 영향 (Effects of Cognitive Function on Physical Performance and Functional Activities in Persons with Chronic Hemiparetic Stroke)

  • 나은진;황수진
    • PNF and Movement
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    • 제17권1호
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    • pp.31-39
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    • 2019
  • Purpose: Cognitive function is a main concern for rehabilitation progression in individuals who have sustained brain damage, even among those whose motor function has returned after brain damage. The purpose of this study was to investigate how cognitive impairment relates to functional independence in postural stability and gait performance in patients with chronic hemiparetic stroke. Methods: This was an observational design in an outpatient rehabilitation hospital. Twenty-eight adults with chronic hemiparetic stroke, receiving a course in an outpatient rehabilitation program, participated in this study. They were divided into two groups (i.e., non-cognitive impairment and cognitive impairment groups) via a cut-off score of 23 or less on a mini-mental state examination. Functional independence was assessed with the timed up-and-go test (TUG), 10-meter walk test (10mWT), five times sit-to-stand test (FTSST), Berg balance scale (BBS), and modified Barthel index (MBI). The independent t-test was used for statistical analysis when comparing the two groups. Results: The cognitive impairment group had less functional independence, balance, and gait performance than those of the non-cognitive impairment group had. The former also showed a statistically significant decrease in their TUG score, FTSST score, BBS score, and MBI score compared to the latter, but not in their 10mWT score (p<0.05). Although the non-cognitive impairment group walked faster than the cognitive impairment group did, that difference was not statistically significant (p>0.05). Conclusion: The results of this study suggest that cognitive impairment relates to functional independence in postural stability and the activities of daily living. In rehabilitation settings, cognitive impairment would be considered a major component in therapeutic rehabilitation to overcome the patients difficult physical problems and to treat for improving functional independence more after stroke.

다양한 두께의 알루미늄 판을 이용한 MTF 측정에 관한 연구 (Modulation Transfer Function with Aluminum Sheets of Varying Thickness)

  • 이동주;김미영;문영민;정동혁
    • 한국의학물리학회지:의학물리
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    • 제27권2호
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    • pp.55-63
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    • 2016
  • 본 연구에서는 방사선치료기용 CBCT의 영상과 같이 해상도가 낮은 경우에 적용할 수 있는 MTF (modulation transfer function) 평가 방법을 고안하였다. 본 연구에서는 두꺼운 알루미늄 판의 영상을 이용하여 중복 표본(oversampling) 방법과 두께 보정 방법을 적용하여 MTF를 결정하였다. 다양한 알루미늄 판의 두께(0.3~1.2 mm)에 대해 MTF를 분석하였으며 경사 영상과 평행 영상의 경우에 대해서도 비교하였다. 연구 결과 치료계획용 CT인 경우에 알루미늄의 두께가 0.8 mm 이하 일 경우 MTF 측정이 가능한 것으로 나타났다. 따라서 두꺼운 알루미늄 판과 두께 보정을 이용한 MTF 측정이 CT 영상에서 가능하였다.

VR 영화에서 암묵적 프레임의 존재 (The Existence of Implicit Frames in VR Movies)

  • 김태은
    • 한국콘텐츠학회논문지
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    • 제18권8호
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    • pp.272-286
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    • 2018
  • VR영화는 일반영화에서의 스크린 화면과 관객과의 관계가 전혀 다르게 형성된다. 관객이 곧 카메라가 되고 카메라의 시점의 주체가 되기 때문에 1인칭 시점에 대한 고찰과 서사를 전달하는 프레임의 편집을 대체할 VR영화만의 프레임 이론이 필요하다. VR영화의 서사전달기능을 하는 프레임의 존재를 드러나지 않으면서 상징적 서사기능을 한다는 의미로써 '암묵적'프레임이라 명명하고 이와 관련된 이론적 배경으로 원씬 원컷으로 제작된 쇼쿠로프감독의 <러시아방주>와 외화면적 요소, 제4의 벽의 개념을 가져올 수 있다. VR영화 속 관객은 현존하지만 동시에 화면 안에서 부재하는 역설적인 딜레마를 가지고 서사에 몰입하게 되면서 하이퍼리얼리티를 겪는다. VR영화 공간에서 시선을 움직이는 시선의 블로킹, 실제와 가상사이의 현존을 묶어주는 원격현존의 속성을 지닌다.

Vibration Suppression Control for an Articulated Robot: Effects of Model-Based Control Applied to a Waist Axis

  • Itoh, Masahiko;Yoshikawa, Hiroshi
    • International Journal of Control, Automation, and Systems
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    • 제1권3호
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    • pp.263-270
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    • 2003
  • This paper deals with a control technique of eliminating the transient vibration of a waist axis of an articulated robot. This technique is based on a model-based control in order to establish the damping effect on the mechanical part. The control model is related to the velocity control loop, and it is composed of reduced-order electrical and mechanical parts. Using this model, the velocity of the load is estimated, which is converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically, and it is added to the velocity command to suppress the transient vibration of a waist axis of the robot arm. The function of this technique is to increase the cut-off frequency of the system and the damping ratio at the driven machine part. This control model is easily obtained from design or experimental data and its algorithm can be easily installed in a DSP. This control technique is applied to a waist axis of an articulated robot composed of a harmonic drive gear reducer and a robot arm with 5 degrees of freedom. Simulations and experiments show satisfactory control results to reduce the transient vibration at the end-effector.

A Study on the Multi-row Progressive Die for Thin Sheet Metal Forming by Computer Simulation

  • Sim, Sung-Bo;Kim, Chung-Hwan
    • 한국기계가공학회지
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    • 제7권3호
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    • pp.75-80
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    • 2008
  • The progressive die performs a work of sheet metal processes with a piercing, notching, embossing, bending, drawing, cut-off etc. in many kinds of pressing. Now a days, these processes have been evaluated as a advanced tooling method to increase the productivity and high quality assurance. The first step analyzing of die design is production part review, then the arrangement drawing of product design and strip process layout design should be done as a next steps with a FEM simulation for its problem solution. After upper procedure were peformed, it was started to make the die, then tryout and its revision of the die and product quality, safety, productivity etc. were done continually. For the all of these process, we mobilized the theory and practice of sheet metal forming, die structure, the function and activity of die components, and the others of die machining, die material, heat treatment and know‐how so on. In this study the features of representative are production part analyzing through the FEM simulation of bending area with a considering spring back problem by DEFORM.

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DC 그리드 안정성 향상을 위해 변압기형 초전도 한류기가 적용된 직류 차단 기술에 관한 연구 (A Study on DC Interruption Technology using a Transformer Type Superconducting Fault Current Limiter to Improve DC Grid Stability)

  • 황선호;최혜원;정인성;최효상
    • 전기학회논문지
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    • 제67권4호
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    • pp.595-599
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    • 2018
  • Interruption system with the transformer type superconducting fault current limiter(TSFCL) is proposed in this paper. The interruption system with a TSFCL is a technology that it maximizes the interruption function of a mechanical DC circuit breaker using a transformer and a superconducting fault current limiter. By a TSFCL, the system limits the fault current till the breakable current range in the fault state. Therefore, the fault current could be cut off by a mechanical DC circuit breaker. The Interruption system with a TSFCL were designed using PSCAD/EMTDC. In addition, the Interruption system with a TSFCL was applied to the DC test circuit to analyze characteristics of a current-limiting and a interruption operation. The simulation results showed that the Interruption system with a TSFCL interrupted the fault current in a stable when a fault occurred. Also, The current-limiting rate of the Interruption system with a TSFCL was approximately 69.55%, and the interruption time was less than 8 ms.

OCCURENCE AND LUMINOSITY FUNCTIONS OF GIANT RADIO HALOS FROM MAGNETO-TURBULENT MODEL

  • CASSANO R.;BRUNETTI G.;SETTI G.
    • 천문학회지
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    • 제37권5호
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    • pp.589-592
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    • 2004
  • We calculate the probability to form giant radio halos (${\~}$ 1 Mpc size) as a function of the mass of the host clusters by using a Statistical Magneto-Turbulent Model (Cassano & Brunetti, these proceedings). We show that the expectations of this model are in good agreement with the observations for viable values of the parameters. In particular, the abrupt increase of the probability to find radio halos in the more massive galaxy clusters ($M {\ge} 2{\times}10^{15} M_{\bigodot}$) can be well reproduced. We calculate the evolution with redshift of such a probability and find that giant radio halos can be powered by particle acceleration due to MHD turbulence up to z${\~}$0.5 in a ACDM cosmology. Finally, we calculate the expected Luminosity Functions of radio halos (RHLFs). At variance with previous studies, the shape of our RHLFs is characterized by the presence of a cut-off at low synchrotron powers which reflects the inefficiency of particle acceleration in the case of less massive galaxy clusters.

Slurry wall 공법에서 안정액의 역할 (I) : 대형모형실험과 설계절차 (The Fluid Loss and Sealing Mechanisms in Slurry Trench Condition (I) : A Large Scale Test and Design Procedure)

  • Kim, Hak-Moon
    • 한국지반공학회논문집
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    • 제18권4호
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    • pp.239-248
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    • 2002
  • 안정액(bentonite slurry)을 이용한 지하연속벽의 건설은 굴착된 trench 내에서 안정액이 침투케익과 표면케익을 포함한 불투수막을 형성함으로서 trench 의 안정성을 유지할 수가 있다. 그러므로 구조용 지하연속벽 건설이나 폐기물 매립장의 차수용 연속벽 건설시 지반조건 및 주변여건의 변화에 의하여 여러 가지 문제가 발생 될 수 있다. 본 논문은 안정액 유출과 불투수케익 형성과정을 대형실험으로 모델링하여 그 결과가 slurry trench 안정성에 미치는 영향을 평가하고, 현장조건에 적합한 설계절차를 제시하였다.