• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.5
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• pp.243-248
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• 2013

Reliability evaluation is important task in embedded system. It can avoid potential failures and manage the vulnerable components of embedded system effectively. Dynamic fault tree analysis is one of the reliability evaluation methods. It can represent dynamic characteristics of a system such as fault & error recovery, sequence-dependent failures. In this paper, the steering system, which is embedded system in vehicles, is represented using dynamic fault tree. We evaluate the steering system using approximation algorithm based on Simpson's rule. A set of simulation results shows that proposed method overcomes the low accuracy of classic approximation method without requiring no excessive calculation time of the Markov chain method.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.52-60
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• 2000

In order to design a reliable machine component efficiently, it is necessary to set up the process of durability analysis using computer simulation technique. In this paper, two methods for dynamic stress calculation, which are basis of durability analysis, are reviewed. Then, a user-oriented dynamic stress analysis program is developed from these two algorithms together with a general-purpose flexible body dynamic analysis and structural analysis programs. Finally, a slider-crank mechanism which has a flexible connecting-rod is chosen to show the special characteristics of these two dynamic stress calculation methods.

• Structural Engineering and Mechanics
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• v.8 no.2
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• pp.151-164
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• 1999

The large deflection theory of the Mindlin plate and Galerkin's method are employed to examine the static responses of a plate produced by the weight of the plate, and the dynamic responses of the plate caused by the coupling effect of these static responses with a set of moving forces. Results obtained by the large deflection theory are compared with those by the small deflection theory. The results indicate that the effect of weight of the plate increases the modal frequencies of the structure. The deviations of dynamic transverse deflection and of dynamic bending moment produced by a moving concentrated force between the two theories are significant for a thin plate with a large area. Both dynamic transverse deflection and dynamic bending moment obtained by the Mindlin plate theory are greater than those by the classical plate.

• Journal of Ship and Ocean Technology
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• v.12 no.2
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• pp.1-15
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• 2008

The main idea of this paper introduce stochastic structural parameters and random dynamic excitation directly into the dynamic functional variational formulations, and developed the nonlinear dynamic analysis of a stochastic variational principle and the corresponding stochastic finite element method via the weighted residual method and the small parameter perturbation technique. An interpolation method was adopted, which is based on representing the random field in terms of an interpolation rule involving a set of deterministic shape functions. Direct integration Wilson-${\theta}$ Method was adopted to solve finite element equations. Numerical examples are compared with Monte-Carlo simulation method to show that the approaches proposed herein are accurate and effective for the nonlinear dynamic analysis of structures with random parameters.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.127-134
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• 1995

The dynamic characteristics of a system can be critically influenced by system uncertainty, so the dynamic system must be analyzed stochastically in consideration of system uncertainty. This study presents a generalized stochastic model of dynamic system subjected to bot external and parametric nonstationary stochastic input. And this stochastic system is analyzed by a new stochastic process closure method and moment equation method. The first moment equation is numerically evaluated by Runge-Kutta method. But the second moment equation is founded to constitute an infinite coupled set of differential equations, so this equations are numerically evaluated by cumulant neglect closure method and Runge-Kutta method. Finally the accuracy of the present method is verified by Monte Carlo simulation.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.201-208
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• 1999

Pile driving technique has been regarded as the most reliable way of constructing deep foundations. Engineers have long believed that the quality of the installed piles is a simple function of the set values which can easily be obtained from the field pile driving records. Consequently most of the local building codes are based on the dynamic formula. However it has been proven that the quality of the driven pile is influenced not only by the set values but also by various factors, such as hammer performance, helmet characteristics, time dependent geotechnical characteristics of the site, etc., from the results of various researches made during the last two decades. In this paper an appropriate quality control scheme has been proposed by taking various influencing factors into consideration.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.8
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• pp.744-750
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• 2010

To segment instances of vehicle classes in a sparse stereo-matching data set, this paper presents an algorithm for clustering based on DP (Dynamic Programming). The algorithm is agglomerative: it begins with each element in the set as a separate cluster and merges them into successively larger clusters according to similarity of two clusters. Here, similarity is formulated as a cost function of DP. The proposed algorithm is proven to be effective by experiments performed on various images acquired by a moving vehicle.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.548-550
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• 2010

The droplet motion on a flat substrate with contact angle hysteresis is studied by solving the equations governing the conservation of mass and momentum. The liquid- gas interface is determined by an level-set method which is based on a sharp-interface representation for accurately imposing the matching or coupling conditions at the interface. The method is modified to treat the dynamic contact angle at the liquid-gas-solid interface. The computations are performed to investigate a droplet impact and merging pattern on a flat substrate to find a optimal condition in a micro-line patterning process. The effects of dynamic contact angles on droplet motion are quantified.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.55-60
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• 1992

The IEEE 802.4 priority mechanism can be used to handle multiple data access classes of traffic. Several timers are used to realize the priority mechanism. The performance and stability of a token bus network depend on the assignment of such timers. In this peper, we present a dynamic timer assignment algorithm for the token passing bus network. The presented algorithm has simple structure for real-time applications and adaptively controls the set of initial timer values according to the offered traffic load. The assignment of the set of timers becomes easy due to the presented algorithm. Based on the iterative algorithm, some solutions such as mean waiting time are derived.

• PNF and Movement
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• v.8 no.1
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• pp.59-65
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• 2010

Purpose : The purposes of this study was to determine the effect of plyometric training and agility training on SEBT and dynamic balance of health young. Methods : Thirty healthy subjects in their 20s were randomly assigned to a plyometric exercise group, an agility training group, and a control group; each group had 10 subjects. The training starts first 2set after more 1set 2 weeks. SEBT is measured every two weeks. Results : The results of this research were as followings: (1) After treatment, there were significant SEBT scores differences in both plyometric and agility group compared with pre-treatment(p<0.05). (2) After treatment, there were significant SEBT scores differences in both agility and control group compared with pre-treatment (p<0.05). Conclusion : It was concluded that ployometric training was effective for improving balance than agility and control group. Therefore, further studies are required to investigate the effect of plyometric training for improving balance with sports injury patient.