• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.275-285
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• 1995

In recent years there has been increasing interest in the issue of process centering in manufacturing process, The traditional process capability indices Cp, Cpk and Cpu are used to provide measure of process performance, but these indices do not represent the issue of process centering. A new measure of the process capability index Cpm is proposed that takes into account the proximity to the target value as well as the process variation when assessing process performance. However, Cpm only considers acceptance cost for deviation from target value within specification limits, do not includes economic consideration for rejected items. This paper proposes flexible process performance measures that considered quadratic loss function caused by quality deviation within specification limits, rejection cost associated with the disposition of rejected items, and inspection cost. In this model disposition of rejected items are considered under perfect corrective procedures and the absence of perfect corrective procedures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5496-5521
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• 2018

Object detection and tracking is the basic capability of mobile robots to achieve natural human-robot interaction. In this paper, an object tracking system of mobile robot is designed and validated using improved multiple instance learning algorithm. The improved multiple instance learning algorithm which prevents model drift significantly. Secondly, in order to improve the capability of classifiers, an active sample selection strategy is proposed by optimizing a bag Fisher information function instead of the bag likelihood function, which dynamically chooses most discriminative samples for classifier training. Furthermore, we integrate the co-training criterion into algorithm to update the appearance model accurately and avoid error accumulation. Finally, we evaluate our system on challenging sequences and an indoor environment in a laboratory. And the experiment results demonstrate that the proposed methods can stably and robustly track moving object.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.4
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• pp.177-185
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• 2021

Over the past 40 years, Korea's defense industry has been deepening into a low-efficiency industrial structure as the government directly controls prices, quantities, and costs. By implementing the Defense Industry Building Act in 2021, the government is creating a healthy ecosystem for the defense industry and strengthening its global competitiveness. In this study, based on KPC's Productivity Management System (PMS), a diagnostic model of defense companies implemented since 2013, the on-site diagnosis was performed from 4 to 28 days depending on the size of the company data was collected based on the results. The causal relationship was analyzed through structural equation model path analysis for the effect of innovation capability on productivity performance. As a result, it suggests that defense materials suppliers should focus on which core processes to innovate and strengthen and improve their innovation capabilities.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.97-109
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• 2020

On March 11, 2011, an earthquake followed by a tsunami caused an extended station blackout (SBO) at the Fukushima Dai-ichi NPP Units. The accident was initiated by a total loss of both onsite and offsite electrical power resulting in the loss of the ultimate heat sink for several days, and a consequent core melt in some units where proper mitigation strategies could not be implemented in a timely fashion. To enhance the plant's coping capability, the Diverse and Flexible Strategies (FLEX) were proposed to append the Emergency Operation Procedures (EOPs) by relying on portable equipment as an additional line of defense. To assess the success window of FLEX strategies, all sources of uncertainties need to be considered, using a physics-based model or system code. This necessitates conducting a large number of simulations to reflect all potential variations in initial, boundary, and design conditions as well as thermophysical properties, empirical models, and scenario uncertainties. Alternatively, data-driven models may provide a fast tool to predict the success window of FLEX strategies given the underlying uncertainties. This paper explores the applicability of Artificial Intelligence (AI) to identify the success window of FLEX strategy for extended SBO. The developed model can be trained and validated using data produced by the lumped parameter thermal-hydraulic code, MARS-KS, as best estimate system code loosely coupled with Dakota for uncertainty quantification. A Systems Engineering (SE) approach is used to plan and manage the process of using AI to predict the success window of FLEX strategies under extended SBO conditions.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.456-458
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• 2009

소프트웨어의 크기가 커지고 복잡도가 증가함에 따라 소프트웨어 품질의 중요성은 점점 증대되고 있다. 소프트웨어의 품질 향상을 위해 소프트웨어 개발 조직은 테스트와 동료검토와 같이 제품 품질 향상을 위한 노력과 CMMI(Capability Maturity Model Integration), 소프트웨어프로세스 품질인증 기준과 같은 프로세스 품질 향상 노력을 하고 있다. 그러나 이러한 소프트웨어 분야의 품질 관리의 노력과 효과에 소요되는 품질비용에 대한 연구는 제조업이나 건설업 등 타 분야에 비해 부족한 실정이다. 본 연구에서는 소프트웨어 프로세스 개선을 위한 모델인 CMMI의 성숙도 레벨에 기반하여, K사의 품질비용관리 방안 적용 결과를 바탕으로 CMMI 성숙도 각 레벨마다 소프트웨어 개발 조직이 품질비용을 관리를 위한 목적과 활동으로 정의된 품질비용 관리 모델의 개발을 연구하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.2
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• pp.146-154
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• 2000

An $H\infty$ controller is designed for active suspensions of vehicles using 7-degree-of-freedom full-car model. Its performance robustness as well as stability robustness to system parameter variations and unmodelled dynamics are assured through the $\mu$-framework. The performance of the $H\infty$ controller is compared with that of a LQC controller in compute simulations. From the simulations it is found that the active suspension with the $H\infty$ controller reduces the acceleration and motion of the sprung mass in the heaving rolling and pitching directions when the car is driven on a normal road or through an asymmetric bump. The suspension stroke and the road holding capability are also improved with a relatively small level of power consumption. Overall the $H\infty$ controller shows a more robust performance than that of the LQG design.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.635-639
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• 2004

In this paper, we present a novel approach for the structure of Fuzzy Neural Network(FNN) based on wavelet function and apply this network structure to the modeling of chaotic nonlinear systems. Generally, the wavelet fuzzy model(WFM) has the advantage of the wavelet transform by constituting the fuzzy basis function(FBF) and the conclusion part to equalize the linear combination of FBF with the linear combination of wavelet functions. However, it is very difficult to identify the fuzzy rules and to tune the membership functions of the fuzzy reasoning mechanism. Neural networks, on the other hand, utilize their learning capability for automatic identification and tuning. Therefore, we design a wavelet based FNN structure(WFNN) that merges these advantages of neural network, fuzzy model and wavelet transform. The basic idea of our wavelet based FNN is to realize the process of fuzzy reasoning of wavelet fuzzy system by the structure of a neural network and to make the parameters of fuzzy reasoning be expressed by the connection weights of a neural network. And our network can automatically identify the fuzzy rules by modifying the connection weights of the networks via the gradient descent scheme. To verify the efficiency of our network structure, we evaluate the modeling performance for chaotic nonlinear systems and compare it with those of the FNN and the WFM.

• Smart Structures and Systems
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• v.31 no.1
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• pp.29-43
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• 2023

This study investigates the possibility of damage detection of a real bridge by means of a modal parameter-based finite element (FE) model update. Field moving vehicle experiments were conducted on an actual steel plate girder bridge. In the damage experiment, cracks were applied to the bridge to simulate damage states. A fast Bayesian FFT method was employed to identify and quantify uncertainties of the modal parameters then these modal parameters were used in the Bayesian model update. Material properties and boundary conditions are taken as uncertainties and updated in the model update process. Observations showed that although some differences existed in the results obtained from different model classes, the discrepancy between modal parameters of the FE model and those experimentally obtained was reduced after the model update process, and the updated parameters in the numerical model were indeed affected by the damage. The importance of boundary conditions in the model updating process is also observed. The capability of the MCMC model update method for application to the actual bridge structure is assessed, and the limitation of FE model update in damage detection of bridges using only modal parameters is observed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.30-40
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• 2018

The purpose of this study is to examine the effect of project-based organizational resources on the business performance in the resource-based view (RBV) and dynamic capability one and analyze their relationship through an integrated model. The RBV argues that firms get competitive advantages when they have VRIN characterized resources but dynamic capability view argues that RBV has its limitation under volatility so it enables them to obtain competitive advantages in ever changing environments. This study analyzes data collected from 270 survey questionnaires on the project management related staff at the project-based organization among major companies in Korea. The result demonstrates that two project organizational resources on strategic and executional management with VRIN characteristics are found to bring positive effects on the organizational dynamic capabilities and also the dynamic capabilities such as integration & reconfiguration, organizational learning are verified to bring meaningful positive effects on the business performance. On the other hand, unlike previous studies, ambidexterity has quite a weak effect on the business performance. Therefore, we expect that the resources of the project-based organization with VRIN lead to strengthen the firm's business performance through organizational dynamic capabilities and produce high performance through the integrated model of RBV and dynamic capability one. The study has academic meanings that widely confirm the effects and characteristics of main elements of VRIN project organizational resources on the business performance of competitive advantage through the dynamic capabilities of the organization by the regression on the precedent studies regarding the project management resources and their relationship with the VRIO characteristics. The practical implication is that it is preferentially necessary for the organization to obtain VRIN resources and organizational dynamic capabilities, especially organizational learning to have sustainable competitive advantages.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.68
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• pp.85-94
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• 2001

Most of customers want to know how to develop the computer system they want to get to use according to the their requirements. This study presents a Computer Integration management System for Quality (CISQ) model for system-integration organizations, which need to demonstrate their capability to consistently provide computer integrated system that meets customer satisfaction and applicable regulatory requirements. The Plan.Do.Check.Act(PDCA) cycle called by Doming wheel expresses the basic concept of continuous improvement action in order to emphasize on achieving business goal. It is useful for providing full competence of a system-integration organization to integrate management systems based on the international management system, and to take an advantage in its market. This study specifies International Certification Network Business Excellence Concept(IBEC) approach to ensure a harmonized integration of the variety of management systems and thereby produce synergy effect. The end part of this study specifies a Assessment Model including an assessment concept adding to the compliance audit according to the CISQ for the continuous improvement. A simple application on Failure Modes and Effects Analysis(FMEA) in testing phase in project life cycle has been done.