• Journal of Korean Port Research
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• v.13 no.1
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• pp.79-86
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• 1999

This paper deals with the evaluation problem of complex systems by introducing a fuzzy approach. The authors are functionally supposing a hierarchical structure model of a complex system and give light on the following problems. First for the purpose of clarifying the characteristics of measures the property and differences between two method such as linear and fuzzy viewpoint are discussed through two level-down evaluation process. Second the integrated evaluation process which keeps reversibility between hierarchical levels is discussed and obtained some necessary conditions for reversibility of fuzzy evaluation. From these results it is expected that the fuzzy approach overcomes partly the limitation of reductionism at the hierarchical evaluation of complex systems.

• Korean System Dynamics Review
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• v.13 no.1
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• pp.5-40
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• 2012

This study focus on oriental way for Win-win leadership of modern time using systems thinking approach. We constructed concept, 'Modesty Leadership' from oriental bible- Tao Te Ching, Change Ching, the Analects of Confucius. This work described in the paper based on case collected from 2011 Seoul city mayor election in the Korea. There are three initial aims : to confirm what feedback loop affected approval rating, to determine how these feedback interacted and to establish the significance of cognitive mapping. The use of system thinking to model cognitive mapping of political election untraditional approach in study of oriental bible. This approach is valuable in that it can be to understand management strategies and their effect on decision making.

• Journal of Korean Society for Quality Management
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• v.32 no.2
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• pp.154-167
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• 2004

The TOC/DBR and Six Sigma are the most attention-getting concepts for managing manufacturing companies in Korea. Using the ideas and methods of the TOC/DBR, companies can achieve a large reduction of work-in-process and finished-good inventories, significant improvement in scheduling performance, and substantial earnings increase. The Six Sigma approach derives the overall process of selecting the right projects based on their potential to improve performance metrics and selecting/training the right people to get the business results. These two concepts have different backgrounds and different viewpoints for production systems. So, if the two concepts collaborate each other, the synergy effects to innovate production systems can be expected. This paper proposes a new approach to implement the TOC/DBR concepts in production systems. This approach uses some concepts of Six Sigma which stresses educations, project approaches (step by step procedure using a Roadmap), and improvement philosophy.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.5
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• pp.462-469
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• 2005

A top-down approach is known to be a useful and effective technique for the design and analysis of metabolic systems. In this Study, we have constructed a grouped metabolic network for Lactococcus lactis under aerobic conditions using grouped enzyme kinetics. To test the usefulness of grouping work, a non-grouped system and grouped systems were compared quantitatively with each other. Here, grouped Systems were designed as two groups according to the extent of grouping. The overall simulated flux values in grouped and non-grouped models had pretty similar distribution trends, but the details on flux ratio at the pyruvate branch point showed a little difference. This result indicates that our grouping technique can be used as a good model for complicated metabolic networks, however, for detailed analysis of metabolic network, a more robust mechanism Should be considered. In addition to the data for the pyruvate branch point analysis, Some major flux control coefficients were obtained in this research.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.4
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• pp.782-804
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• 2011

In video-based recognition systems, stationary cameras are used to monitor an area of interest. These systems focus on a segmentation of the foreground in the video stream and the recognition of the events occurring in that area. The usual approach to discriminating the foreground from the video sequence is background subtraction. This paper presents a novel background subtraction method based on a probabilistic approach. We represent the posterior probability of the foreground based on the current image and all past images and derive an updated method. Furthermore, we present an efficient fusion method for the color and edge information in order to overcome the difficulties of existing background subtraction methods that use only color information. The suggested method is applied to synthetic data and real video streams, and its robust performance is demonstrated through experimentation.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1386-1396
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• 2017

In this paper, a new approach is proposed to select the optimal sitting and sizing of distributed solar photovoltaic generation (SPVG) in a radial electrical distribution systems (EDS) considering load/generation uncertainties. Here, distributed generations (DGs) allocation problem is modeled as optimization problem with network loss based objective function under various equality and inequality constrains in an uncertain environment. A boundary power flow is utilized to address the uncertainties in load/generation forecasts. This approach facilitates the consideration of random uncertainties in forecast having no statistical history. Uncertain solar irradiance is modeled by beta distribution function (BDF). The resulted optimization problem is solved by a new Dynamic Harmony Search Algorithm (DHSA). Dynamic band width (DBW) based DHSA is proposed to enhance the search space and dynamically adjust the exploitation near the optimal solution. Proposed approach is demonstrated for two standard IEEE radial distribution systems under different scenarios.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.57
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• pp.63-76
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• 2000

In today's competitive, market-driven world, a company's survival rests in its ability to provide quality performance products accompanied by total customer satisfaction. To satisfy the needs of customers, companies strive for defect free performances. This requires companies establish an integrated quality management system based on ISO 9000, ISO 14000, QS-9000, AS-9000, TL-9000, 100 PPM, and six sigma. This paper suggests that how to integrate implementation of quality certification systems and six sigma is an important approach in the continuous quality improvement, and six sigma efforts have become one of the key success approach. Through the various survey of total quality management system approach, it is intended to provide a chance to benchmark or give a cue on how to conduct the quality management innovation.

• International Journal of Control, Automation, and Systems
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• v.5 no.1
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• pp.1-7
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• 2007

In this paper, the necessary and sufficient conditions for strict positive realness of the rational transfer functions directly from basic definitions in the frequency domain are studied. A new frequency domain approach is used to check if a rational transfer function is a strictly positive real or not. This approach is based on the Taylor expansion and the Maximum Modulus Principle which are the fundamental tools in the complex functions analysis. Four related common statements in the strict positive realness literature which is appeared in the control theory are discussed. The drawback of these common statements is analyzed through some counter examples. Moreover a new necessary condition for strict positive realness is obtained from high frequency behavior of the Nyquist diagram of the transfer function. Finally a more simplified and completed conditions for strict positive realness of single-input single-output linear time-invariant systems are presented based on the complex functions analysis approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.5
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• pp.769-779
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• 1997

This paper presents an approach to multiple objective scheduling of flexible manufacturing systems(FMS). The approach is an extension of the scheduling method that formulates scheduling problems using Petrinets, and applies heuristic search to find optimal or near-optimal schedules with a single objective. New evaluation functions are developed to optimize simultaneously the makespan and the total operating cost. A scheduling example is used to demonstrate the effectiveness of the proposed approach.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.335-335
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• 2000

Applications such as unmanned aerial vehicles (UAVs), autonomous underwater vehicles (AUVs) and the time varying nature of their navigation, guidance and control systems motivate an integrated approach to trajectory general ion and trajectory tracking for autonomous vehicles. In this paper, an experimental testbed was designed for studying this integrated trajectory control approach. In this paper we apply the separating approach to an autonomous nonlinear vehicle system. A new linear matrix inequality based H$_{\infty}$ control technique for periodic time-varying systems is applied to the role of trajectory tracking. Trajectory general ion is accomplished by exploit ing the differential flatness property of the vehicle system; this at lows product ion of desired feasible nominal or reference trajectories from certain ″flat'system outputs. Simulation and experimental results are presented showing stable tracking of a periodic circular trajectory.