• Convergence Security Journal
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• v.7 no.2
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• pp.1-8
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• 2007

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault (intensity function). In this paper, intensity function of Goel-Okumoto model was reviewed, proposes Kappa (2) and the Burr distribution, which maked out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method. For model determination and selection, explored goodness of fit (the error sum of squares) The methodology developed in this paper is exemplified with a software reliability real data set introduced by NTDS (Naval Tactical Data System)

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.665-671
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• 2010

This paper propose the DDEGST(divergent-direction-emphasis generalized symmetry transform) which emphasis the symmetry of divergent intensity orientation for effective target extraction in FLIR(forward looking infra-red) images. In the proposed method, we use the exponential function instead of cosine function as a phase weight function in the generalized symmetry transform for effective target extraction in FLIR images which contain a target with higher intensity than a background intensity. To evaluate the performance of the proposed method, we compare the proposed mehtod with conventional GST method in experiments. We prove that the proposed method have better performance in IR images.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.231-239
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• 2006

An experimental investigation of a Reversible Loop Heat Pipe (RLHP) was conducted to determine the operating limits and performance characteristics as functions of the thermophysical parameters, the heat input, and the cooling intensity. Variations in both temperature and heat transport capacity were measured and analyzed in order to accurately evaluate the transient operating characteristics. In addition, the maximum heat transport as a function of the mean evaporator temperature, the ratio of heat transport to heater input power as a function of the mean evaporator temperature, and the overall thermal resistance as a function of the overall heat transport capacity were examined as well. Results indicated that the cooling intensity played an important role on the operating characteristics and performance limitation. The maximum heat transports corresponding to cooling intensity $72W/^{\circ}C$ and $290W/^{\circ}C$ were 446 W and 924 W, respectively. Also, observation of the startup characteristics indicated that the mean evaporator temperature should be maintained between $40^{\circ}C$ and $60^{\circ}C$, and overall thermal resistance were measured as $0.02^{\circ}C/W$.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.463-469
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• 2021

Objective: If non-surgical treatment fails, arthroscopic rotator cuff repair (ARCR) is recommended, and ARCR considers graft augmentation in consideration of size, direction, and re-tear. It is reported to have potential benefits by improving the healing rate as it can fill the gaps that have been left behind. The purpose of this study is to investigate the effect of structural changes observed after ARCR on muscle action through magnetic resonance imaging and to investigate the effect of appropriate physical therapy required for graft augmentation in the general ARCR rehabilitation protocol. Case presentation: A 47-year-old male hospitalized for postoperative rehabilitation following ARCR participated in a 5-week physical therapy intervention. The postoperative day was 6 months, but due to shooting pain and shoulder dysfunction,and the movement of the shoulder was compensatory motion, not normal motion. Physical agents, manual therapy, and supervised exercise for 110 minutes per session were performed 3 times a week, and pain intensity, range of motion, function, and strength were evaluated. Results: As a result of the study, the patient showed positive improvement in pain intensity, range of motion, function, and strength. In addition, normal scapulohumeral rhythm movement was observed. Conclusions: According to the results of this case, appropriate physical therapy according to the compensatory motion shown in the structural changes after ARCR can positively improve the pain intensity, range of motion, function, and strength of ARCR patients.

• Journal of information and communication convergence engineering
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• v.4 no.3
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• pp.101-104
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• 2006

We have investigated the spectral characteristics of the semiconductor lasers locked to the sidebands of the master laser in this paper, which were expressed by a series of the Bessel function. The numerical model for the semiconductor lasers based on the typical Lang's equation has been extended in order to take into account the simultaneous injection of the multiple sidebands of the directly modulated ML. We analyses characteristics of direct intensity modulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1017-1025
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• 2000

The human auditory system has been shown to posses remarkable abilities in the localization and tracking of sound sources. The localization is the result of processing two primary acoustics cues. These are the interaural time difference(ITD) cues and interaural intensity difference(IID) cues at the two ears. In this paper, we propose TEPILD(Time Energy Previous Integration Location Detector) model. TEPILD model is constructed with time function generator, energy function generator, previous location generator and azimuth detector. Time function generator is to process ITD and energy function generator is to process IID. Total average accuracy rate is 99.2%. These result are encouraging and show that proposed model can be applied to the sound source location detector.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.5
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• pp.357-364
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• 1998

To investigate accuracies between intensity method and count method for measurement of the fiber orientation distribution, fiber orientation function is derived by drawing simulation figure for the fiber orientation as varying fiber aspect ratio, fiber area ratio, and fiber orientation state, respectively. The values of fiber orientation function measured by intensity method and count method are compared with the calculated ones from simulation figures. The results show that measurement accuracy of fiber orientation angle distribution obtained by count method is by 4% higher than that by intensity method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1120-1131
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• 2003

A recently developed numerical method based on a mixed volume and boundary integral equation method is applied to calculate the accurate stress intensity factors at the crack tips in unbounded isotropic solids in the presence of multiple anisotropic inclusions and cracks subject to external loads. Firstly, it should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. Secondly, this method takes full advantage of the capabilities developed in FEM and BIEM. In this paper, a detailed analysis of the stress intensity factors are carried out for an unbounded isotropic matrix containing an orthotropic cylindrical inclusion and a crack. The accuracy and effectiveness of the new method are examined through comparison with results obtained from analytical method and volume integral equation method. It is demonstrated that this new method is very accurate and effective for solving plane elastostatic problems in unbounded solids containing anisotropic inclusions and cracks.

• Geomechanics and Engineering
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• v.22 no.2
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• pp.187-196
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• 2020

The changeable stress environment directly affect the propagation law of a stress wave. Stress wave propagation tests in sandstone with different axial stresses were carried using a modified split Hopkinson Pressure bar (SHPB) assuming the sandstone has a uniform pore distribution. Then the waveform and stress wave energy dissipation were analyzed. The results show that the stress wave exhibits the double peak phenomenon. With increasing axial stress, the intensity difference decreases exponentially and experiences first a dramatic decrease and then gentle development. The demarcation stress is σ/σ_c=30%, indicating that the closer to the incident end, the faster the intensity difference attenuates. Under the same axial stress, the intensity difference decreases linearly with propagation distance and its attenuation intensity factor displays a quadratic function with axial stress. With increasing propagation distance, the time difference decays linearly and its delay coefficient reflects the damage degree. The stress wave energy attenuates exponentially with propagation distance, and the relations between attenuation rate, attenuation coefficient and axial stress can be represented by the quadratic function.

• Composites Research
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• v.13 no.4
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• pp.67-74
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• 2000

The general solution of the anti-plane shear problem for the curved interfacial crack between viscoelastic foam and composites was investigated with the complex variable displacement function. Kelvin-Maxwell three parameter model is used to present viscoelasticity and the Laplace transform was applied to treat the viscoelastic characteristics of foam in the analysis. The stress intensity factor near the interfacial crack tip was predicted by considering both anisotropic and viscoelastic properties of two different materials. The results showed that the stress intensity factor increased with increasing the curvature of the curved interfacial crack and it also increased and eventually converged to a specific value with increasing time. The stress intensity factor increased with increasing the ratio of stiffness coefficients between foam and composites and the effect of fiber orientation on the stress intensity factor decreased with increasing the ratio of stiffness coefficients between foam and composites.