• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.889-896
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• 2006

The concept of reliability has been applied to the topology optimization based on a reliability index approach or a performance measure approach. Since these approaches, called double-loop single vector approach, require the nested optimization problem to obtain the most probable point in the probabilistic design domain, the time for the entire process makes the practical use infeasible. In this work, new reliability-based topology optimization method is proposed by utilizing single-loop single-vector approach, which approximates searching the most probable point analytically, to reduce the time cost. The results of design examples show that the proposed method provides efficiency curtailing the time for the optimization process and accuracy satisfying the specified reliability.

• The Journal of the Acoustical Society of Korea
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• v.17 no.3E
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• pp.22-26
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• 1998

This paper proposes a simple method to measure system's performance in target tracking problems. Essentially employing the Cramer-Rao Lower Bound (CRLB) on tracking accuracy, an algorithm of predicting system's performance under various scenarios is developed. The input data is a collection of measurements over tim from sensors embedded in Gaussian noise. The target of interest may not maneuver over the processing time interval while the own ship observing platform may maneuver in an arbitrary fashion. The proposed approach is demonstrated and discussed through simulation results.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.635-638
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• 1998

This paper proposes a simple method to measure system's performance in target tracking problems. Essentially employing the Cramer-Rao lower bound (CRLB) on trakcing accuracy, an algorithm of predicting system's performance under various scenarios is developed. The input data is a collection of measurements over time fromsensors embedded in gaussian noise. The target of interest may not maneuver over the processing time interval while the own ship observing platform may maneuver in an arbitrary fashion. Th eproposed approach is demonstrated and discussed through simulation results.

• Journal of the Korean Solar Energy Society
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• v.28 no.4
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• pp.68-75
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• 2008

The purpose of this research is revise the value yield to compensate of measure the difference between computer simulation and the measurement value on the two methods which can calculates thermal performance. The way is need to understand about thermal performance, air tightness, simulations and comparisons of analysis to influence the value of each identified. The opening type of the windows and doors to be used at the analysis are T/T, L/S and SL Different condition of the windows and doors excluded except the opening type. Each of the four samples was selected by the way of opening. Result of the analysis of the difference between measurement and simulation are that T/T approach 5.3%, L/S approach 15.7%, SL approach 21% and the more air-tightness guarantees less difference of the numerical value. Each compensation value calculates by the correlation regression analysis and the air-tightness data. After the compensation of the resulting difference in T/T, L/S, SL indicate 5.4%, 2.5%, 1.0% respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1824-1845
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• 2016

The GMM is a conventional approach which has been recently applied in many face recognition studies. However, the question about how to deal with illumination changes while ensuring high performance is still a challenge, especially with real-world databases. In this paper, we propose a Visual Observation Confidence (VOC) measure for robust face recognition for illumination changes. Our VOC value is a combined confidence value of three measurements: Flatness Measure (FM), Centrality Measure (CM), and Illumination Normality Measure (IM). While FM measures the discrimination ability of one face, IM represents the degree of illumination impact on that face. In addition, we introduce CM as a centrality measure to help FM to reduce some of the errors from unnecessary areas such as the hair, neck or background. The VOC then accompanies the feature vectors in the EM process to estimate the optimal models by modified-GMM training. In the experiments, we introduce a real-world database, called KoFace, besides applying some public databases such as the Yale and the ORL database. The KoFace database is composed of 106 face subjects under diverse illumination effects including shadows and highlights. The results show that our proposed approach gives a higher Face Recognition Rate (FRR) than the GMM baseline for indoor and outdoor datasets in the real-world KoFace database (94% and 85%, respectively) and in ORL, Yale databases (97% and 100% respectively).

• Structural Engineering and Mechanics
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• v.18 no.3
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• pp.287-301
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• 2004

Structural acceleration regulation is a means of managing structural response energy and enhancing the performance of civil structures undergoing large seismic events. A quadratic output regulator that minimizes a measure including the total structural acceleration energy is developed and tested on a realistic non-linear, semi-active structural control case study. Suites of large scaled earthquakes are used to statistically quantify the impact of this type of control in terms of changes in the statistical distribution of controlled structural response. This approach includes the impulses due to control inputs and is shown to be more effective than a typical displacement focused control approach, by providing equivalent or better performance in terms of displacement and hysteretic energy reductions, while also significantly reducing peak story accelerations and the associated damage and occupant injury. For earthquake engineers faced with the dilemma of balancing displacement and acceleration demands this control approach can significantly reduce that concern, reducing structural damage and improving occupant safety.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.781-787
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• 2011

Mine countermeasure missions(MCMs) may induce the loss of human and ship because of the covert of mine. In recent years, unmanned underwater vehicles(UUVs) have emerged as viable technical solution for conductimg underwater search, surveillance, and clearance operations in support of mine countermeasure missions because of her autonomy and long time endurance capability. This paper introduces a technical approach to mine countermeasure mission effectiveness analysis and presents some simulation-based analysis results for engineering of the UUV system definition which could be support analysis of alternatives for system definition and design.

• Journal of applied mathematics & informatics
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• v.13 no.1_2
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• pp.183-194
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• 2003

We will explain a new method for obtaining the nearly optimal domain for optimal shape design problems associated with the solution of a nonlinear wave equation. Taking into account the boundary and terminal conditions of the system, a new approach is applied to determine the optimal domain and its related optimal control function with respect to the integral performance criteria, by use of positive Radon measures. The approach, say shape-measure, consists of two steps; first for a fixed domain, the optimal control will be identified by the use of measures. This function and the optimal value of the objective function depend on the geometrical variables of the domain. In the second step, based on the results of the previous one and by applying some convenient optimization techniques, the optimal domain and its related optimal control function will be identified at the same time. The existence of the optimal solution is considered and a numerical example is also given.

• Physical Therapy Korea
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• v.23 no.1
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• pp.55-64
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• 2016

Background: The International Classification of Functioning, Disability, and Health-core set (ICF-core set) for children and youth (CY) with cerebral palsy (CP) provides a useful conceptual framework and a guide for health care planning and measuring the changes brought by interventions across a multitude of dimensions from body functions to personal activities, social participation, and environmental factors for them. Objects: This single case study was reported to illustrate the use of a goal directed approach in applying the ICF-core set for CY with CP from a physical therapist perspective. Methods: An eleven year old boy with spastic CP, Gross Motor Function Classification System (GMFCS) level V, and his mother participated in an evaluation of his functioning state. The intervention goal was set through an interview using the ICF-core set, Canadian Occupational Performance Measure (COPM) and Goal Attainment Scale (GAS). Physical therapy was carried out on an outpatient basis using a goal directed approach for 30 min, 1 time/week during 12 weeks and the boy's gross motor function was assessed using the Gross Motor Function Measure (GMFM)-66 version (item set 2) before and after the intervention. Results: As measured by the boy's mother, the COPM score showed a meaningful clinical change (performance=mean 3.5, satisfaction=mean 2.5) and the T-score of GAS changed 34.4 after the goal directed approach. The GMFM-66 (item set 2) score changed from 31.8 to 38.7 and evaluation using the ICF-core set displayed improvement in 6 items of activity level between before and after the intervention. Conclusion: The ICF-core set for CY with CP is useful for understanding the overall functioning of CY with this condition and provides an opportunity to share and integrate information and opinions from different disciplines. We consider it as a useful tool in the universal language for the therapy and education of CY with CP.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1A
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• pp.45-52
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• 2009

In conventional structural design, deterministic optimization which satisfies codified constraints is performed to ensure safety and maximize economical efficiency. However, uncertainties are inevitable due to the stochastic nature of structural materials and applied loads. Thus, deterministic optimization without considering these uncertainties could lead to unreliable design. Recently, there has been much research in reliability-based design optimization (RBDO) taking into consideration both the reliability and optimization. RBDO involves the evaluation of probabilistic constraint that can be estimated using the RIA (Reliability Index Approach) and the PMA(Performance Measure Approach). It is generally known that PMA is more stable and efficient than RIA. Despite the significant advancement in PMA, RBDO still requires large computation time for large-scale applications. In this paper, A new reliability-based design optimization (RBDO) method is presented to achieve the more stable and efficient algorithm. The idea of the new method is to integrate a response surface method (RSM) with PMA. For the approximation of a limit state equation, the moving least squares (MLS) method is used. Through a mathematical example and ten-bar truss problem, the proposed method shows better convergence and efficiency than other approaches.