• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.185-196
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• 2021

Objective: Falling is one of main accident to facilitate the physical injuries in order adults. The purpose of the systematic review was to determine the effects of postural balance training whether the recovery of falls in elderly with normal physical function or not throughout summing the selected studies quantitatively. Design: A systematic review Methods: MEDLINE and other four databases were searched up to April 20, 2021 and randomized controlled trials (RCTs) evaluating postural balance approaches on fall risks in elderly. The researched studies excluded the double studies, titles and abstract, and finally full-reported study. The selected RCTs studies were extracted characteristics of the studies and summary of results based on PICOS-SD (population, intervention, comparison, outcomes, and setting- study design) model to synthesize the papers qualitatively. Results: The review involved 22 RCT reports with 4,847 community older adults aged 65 years or over. Nineteen of the selected RCT studies reported dual or multimodal exercises show the beneficial effect for older adults compared to one-type treatment or no intervention. All of selected showed low risk in the selection, attrition, and reporting bias. However, detection bias showed low risk at 75% records of the involved RCTs and performance bias was low risk at only three records. Conclusions: The results of the systematic review propose that a standardized therapeutic approach and the intensity are needed for improving risk of falls in older adults.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.317-327
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• 2009

In adaptive designs important components of clinical trials may be changed based on the results of interim analysis. Several international guidelines point out that such interim analysis should be performed by independent experts who do not participate in clinical trials when adaptive designs are used in therapeutic confirmatory clinical trials, and if not, it may cause bias. The international guidelines recommend the establishment of independent data monitoring committee for conducting interim analysis independently.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.524-527
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• 1997

Conventional target tracking algorithms based on the linear estimation techniques perform quite efficiently when the target motion does not involve maneuvers. Target maneuvers involving short term accelerations, however, cause a bias in the measurement sequence. Accurate compensation for the bias requires processing more samples of which adds to the computational complexity. The primary motivation for employing a neural network for this task comes from the efficiency with which more features can be as inputs for bias compensation. A system architecture that efficiently integrates the fusion capabilities of a trained multilayer neural net with the tracking performance of a Kalman filter is described. The parallel processing capability of a properly trained neural network can permit fast processing of features to yield correct acceleration estimates and hence can take the burden off the primary Kalman filter which still provides the target position and velocity estimates.

• Journal of the Korean Institute of Telematics and Electronics
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• v.9 no.4
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• pp.7-16
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• 1972

A prototype of photoelectric photometer has been developed by all solid state operational amplifiers. The amplification of low-level anode currents from photomultiplier tube corresponding to a given incident light intensity and logarithmic transfer for star's magnitude nleasurements are achieved by the same operational amplifier. It is important to select low input bias currents for stable performance because the resolution is primarily limited by the bias currents. As such, they offer a higher reliable and economical for a large number of electrometer amplifier applications which have traditionaly been fulfilled by vacuum electrometer tubes or vibrating reed electrometers.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1424-1425
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• 2011

비절질 IGZO TFT를 제작하여 양의 DC 및 AC에 대한 bias stability를 측정하였다. 소자특성이 상당부분 양의 방향으로 움직여 전류가 감소하였다. 따라서 기존의 Shift-Register는 양의 스트레스 전압을 지속적으로 받기 때문에 회로가 제대로 동작하지 않을 수 있다. 따라서 우리는 양의 스트레스 전압을 받지않는 새로운 Shift-register를 고안하고 SPICE 시뮬레이션을 통하여 안정한 출력을 확인하였다.

• Journal of Electrical Engineering and Technology
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• v.2 no.4
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• pp.537-542
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• 2007

This paper proposes a 2-step Kalman filter model for land vehicle navigation using civilian-band GPS measurements. The velocity bias caused by the Earth#s rotation would be removed completely when applying this model. Because the linearization of velocity equations in this model is not necessary, the error is significantly reduced. The experiment reveals that estimated position error with stationary data is about 5m during a 15-20 minute interval. The other benefit of this model is that it can be feasibly applied as a GPS receiver module thanks to the small sizes of the necessary manipulating matrices.

• Journal of Magnetics
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• v.15 no.3
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• pp.132-137
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• 2010

Plasma etching of $SiO_2$ contact holes was statistically analyzed by a fractional factorial experimental design. The analysis revealed the dependence of the etch rate and DC self-bias voltage on the input factors of the magnetically enhanced reactive ion etching reactor, including gas pressure, magnetic field, and the gas flow rates of $CHF_3$, $CF_4$, and Ar. Empirical models of the DC self-bias voltage and etch rate were obtained. The DC self-bias voltage was found to be determined mainly by the operating pressure and the magnetic field, and the etch rate was related mainly to the pressure and the flow rates of Ar and $CHF_3$.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.193-196
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• 2001

One of the major reasons for not integrating a VCO on one-chip in a PLL (phase locked loop) system is the large chip-to-chip variation of the VCO (voltage controlled oscillator) center frequency. In this thesis, a simple bias technique is proposed to compensate the process fluctuation. The proposed bias technique is applied to the VCO and it reduces the deviation of the VCO center frequency from 35% to 8 %. With the suggested bias technique, a 400 MHz frequency synthesizer is designed for general purpose. It utilizes a programmable divider for various division ratio. The design methodology provides the possibility of the one-chip solution for a PLL system.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.875-878
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• 1999

In this paper, we measured and simulated the transconductance change of submicron LDD NMOSFETs due to back bias under various channel length, temperature and substrate doping conditions. As back bias is increased, the mobility will decrease and g$_{m}$ decreases according to a conventional model. But as the channel length is reduced, this phenomenon is inverted and g$_{m}$ increases in the submicron region. This can be explained by analyzing the electron quasi Fermi potential in the channel. And the empirical formulae which show the g$_{m}$ change were induced. These will be helpful to enhance the efficiency and precision of IC design.esign.

• The Journal of the Korean dental association
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• v.45 no.3 s.454
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• pp.169-181
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• 2007

In this second part of series report on evidence-based dentistry, the level of evidence and the methods for critical appraisal are discussed. The epidemiologic studies, namely clinical studies have some bias per se, and the degree of bias is somewhat predetermined by the study design. The level of evidence can be defined as the reliability of the clinical study and it is dependent on the degree of bias. Thus, it is important to determine the type of the study and to understand its structure before critically appraising them. Systematic reviews of primary studies, randomized controlled trials, nonrandomized clinical trials, cohort studies, case-control studies, and case reports / series constitute the clinical studies and the level of evidence follows the order of the studies listed above. Critical appraisal is the most important procedure in evidence-based dentistry. It is done to determine the credibility of research papers and their usefulness in the clinician s own practice. Critical appraisal is consisted of multiple questions that are helpful for evaluating validity and usefulness of the studies concerning therapy, diagnosis, prognosis, and causation.