• International Journal of Reliability and Applications
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• v.2 no.4
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• pp.253-262
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• 2001

A k-out-of-n standby system is considered where all of its components are s-independent and classified either working or cold standby connected with imperfect switches. The probability density function of the life length for this system is established in closed form, when the underlying components have constant failure rates. Also the reliability function of the system is derived. Finally, the reliability functions for one, two and three out of four systems are deduced for perfect or imperfect switches and identical or non-identical constant failure rates for working and standby components.

• Journal of Sensor Science and Technology
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• v.24 no.6
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• pp.412-418
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• 2015

In this paper, a new method for obtaining PID coefficients which are essential to a temperature stabilization process has been proposed. This method starts from measuring the open loop transfer function of the module, then the closed loop transfer function embodying PID control can be produced based on this. Finally, the simulations using a few PID coefficients and the performance analysis for those results provide the best PID coefficients which are effective in a fast setting to a target temperature, a less current needed, and less deviation from steady state. The measurement using the derived PID coefficients, $K_p=1.6$,$K_i=0.8$,$K_d=0.3$ showed $T_s=7.4[sec]$, %OS = 16, and stabilization within ${\pm}0.02[^{\circ}C]$ for several hours. In addition to light sources like SOA, the proposed method can be utilized for any device needs temperature stabilization.

• The Pure and Applied Mathematics
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• v.12 no.1
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• pp.47-55
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• 2005

For topological spaces X, Y and the function f : X → Y, it induces a function gr(f) : X → X x Y defined as gr(f)(χ) = (χ, f(χ)), for every χ ∈ X. It deals with some preliminary investigations relating to the behavior of functions and its graph functions. It has also been found that continuous functions are homotopic if and only if their graph functions are homotopic.

• Archives of Craniofacial Surgery
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• v.18 no.2
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• pp.92-96
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• 2017

Background: All nasal bone fractures have the potential for worsening of olfactory function. However, few studies have studied the olfactory outcomes following reduction of nasal bone fractures. This study evaluates posttraumatic olfactory dysfunction in patients with nasal bone fracture before and after closed reduction. Methods: A prospective study was conducted for all patients presenting with nasal bone fracture (n=97). Each patient consenting to the study underwent the Korean version of Sniffin' Sticks test (KVSS II) before operation and at 6 month after closed reduction. The nasal fractures were divided according to the nasal bone fracture classification by Haug and Prather (Types I-IV). The olfactory scores were compared across fracture types and between preoperative and postoperative settings. Results: Olfactory dysfunction was frequent after nasal fracture (45/97, 46.4%). Our olfactory assessment using the KVSS II test revealed that fracture reduction was not associated with improvements in the mean test score in Type I or Type II fractures. More specifically, the mean posttraumatic Threshold, discrimination and identification score decreased from 28.8 points prior to operation to 23.1 point at 6 months for Type II fracture with septal fracture. Conclusion: Our study has revealed two alarming trends regarding post-nasal fracture olfactory dysfunction. First, our study demonstrated that almost half (46.4%) of nasal fracture patients experience posttraumatic olfactory dysfunction. Second, closed reduction of these fractures does not lead to improvements olfaction at 6 months, which suggest that olfactory dysfunction is probably due to factors other than the fracture itself. The association should be further explored between injuries that lead to nasal fracture and the mechanism behind posttraumatic olfactory dysfunction.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.2
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• pp.126-135
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• 2010

The purpose of this study is to investigate the effects of closed and open kinetic chain exercise for increasing knee joint function on the knee position sense in the normal adults. Thirty normal adults(male 15, female 15; mean age: $22.13{\pm}2.58$ years) were participated in this study into two groups, each with 15 people. The group I was trained that closed kinetic chain exercise on the knee joint and the group II was trained that open kinetic chain exercise on the knee joint. Exercise programs performed for 4 weeks, 3 times a week were using Shuttle 2000-1 closed kinetic chain exercise and Knee Extensor open kinetic chain exercise(HUR, Filand). The results of this study were as follows: 1) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 2) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 3) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 4) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 5) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 6) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). In conclusion, these results suggest that closed and open kinetic chain exercise has increased in the knee joint proprioception between before and after training. Especially, closed kinetic chain exercise could be more useful intervention than open kinetic chain exercise for increasing proprioceptive sense.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.984-987
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• 1996

We consider a feedback control system including interval plant where uncertain parameters expressed in the hyperrectangular box X. Here we define the maximum value of the integral of the error(ISE) as the worst performance index(WPI) due to the plant parameter uncertainty. Suppose that the closed loop system retains robust stability and it belongs to type I. Then we show that the WPI occurs only on the exposed edges of Q. In particular, it is also shown that if ISE is a convex function relative to X, the WPI is attained at one of vertices of X. Some examples are given.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1646-1652
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• 2006

A model of mechanical behavior of microcantilever due to intrinsic strain during deposition of MEMS structures is derived. A linear ordinary differential equation is derived for the beam deflection as a function of the thickness of the deposited layer. Closed-form solutions are not possible, but numerical solutions are plotted for various dimensionless ratios of the beam stiffness, the intrinsic strain, and the elastic moduli of the substrate and deposited layer. This model predicts the deflection of the cantilever as a function of the deposited layer thickness and the residual stress distribution during deposition. The usefulness of these equations is that they are indicative of the real time behavior of the structures, i.e. it predicts the deflection of the beam continuously during deposition process.

• Journal of the Korean Mathematical Society
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• v.35 no.3
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• pp.691-712
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• 1998

We consider an M$_1$, M$_2$/G/1/ K retrial queueing system with a finite priority queue for type I calls and infinite retrial group for type II calls where blocked type I calls may join the retrial group. These models, for example, can be applied to cellular mobile communication system where handoff calls have higher priority than originating calls. In this paper we apply the supplementary variable method where supplementary variable is the elapsed service time of the call in service. We find the joint generating function of the numbers of calls in the priority queue and the retrial group in closed form and give some performance measures of the system.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.1010-1019
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• 1994

It is shown that there exists a nonlinear mapping which transforms image features and their changes to the desired camera motion without measuring of the relative distance between the camera and the object. This nonlinear mapping can eliminate several difficulties occurring in computing the inverse of the feature Jacobian as in the usual feature-based visual feedback control methods. Instead of analytically deriving the closed form of this mapping, a Fuzzy Membership Function-based Neural Network (FMFNN) incorporating a Fuzzy-Neural Interpolating Network is used to approximate the nonlinear mapping. Several FMFNN's are trained to be capable of tracking a moving object in the whole workspace along the line of sight. For an effective implementation of the proposed FMF network, an image feature selection process is investigated. Finally, several numerical examples are presented to show the validity of the proposed visual servoing method.

• Annals of Fuzzy Mathematics and Informatics
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• v.16 no.3
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• pp.337-361
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• 2018

We introduce and study some basic properties of rough $I_{\lambda}$-statistical convergent of weight g (A), where $g:{\mathbb{N}}^3{\rightarrow}[0,\;{\infty})$ is a function statisying $g(m,\;n,\;k){\rightarrow}{\infty}$ and $g(m,\;n,\;k){\not{\rightarrow}}0$ as $m,\;n,\;k{\rightarrow}{\infty}$ and A represent the RH-regular matrix and also prove the Korovkin approximation theorem by using the notion of weighted A-statistical convergence of weight g (A) limits of a triple sequence of Bernstein-Stancu polynomials.