• Title/Summary/Keyword: system uncertainty

Search Result 2,446, Processing Time 0.03 seconds

Characteristics and Performance of ERP Adoption in University Organization (대학의 ERP 도입 특성과 성과에 관한 연구)

  • Cho, Sung-Eui
    • Journal of Information Technology Services
    • /
    • v.6 no.2
    • /
    • pp.49-62
    • /
    • 2007
  • Characteristics of the motivation and performance of Enterprise Resources Planning (ERP) adoption in university organization are explored through case studies in this study. Generally, the modules for production, sales, and logistics management in a manufacturing company are substituted with new modules for student support, lecture operations, and research management in ERP for university organization. The motivation of ERP adoption is closely related to the purpose of improvement of business process operations and information system control rather than the environmental factors such as inter-organizational competition or increase of market uncertainty, differentially from enterprises cases. In addition, the financial performance such as cost reduction, labor substitution, and increase of productivity is relatively lower evaluated than the performance on organizational aspects or information system control.

A Study on the AGV Operation Using Production Cycle Time (생산주기를 활용한 AGV 운용에 관한 연구)

  • 김지표
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.27 no.1
    • /
    • pp.107-117
    • /
    • 2002
  • The ever-glowing demands for more responsiveness and more flexibility in manufacturing generate greater expectation for the AGV system. So far. a significant amount of research has been carried out to fulfill those requirements. However, the dynamic characteristics of manufacturing systems make it hard to solve the problem analytically. In this paper, the AGV system is analyzed in the production environments which adopt a cycle time to produce materials. The use of the cycle time could eliminate much of uncertainty Inherent In the manufacturing process so that it is possible to build the deterministic model for the AGV systems, which eventually Produce better results on the important issues such as AGV dispatching, determination of the number of AGVs, and empty vehicle travel time.

Input Constrained Receding Horizon Control with Nonzero Set Points and Model Uncertainties

  • Lee, Young-Il
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.502-502
    • /
    • 2000
  • An input constrained receding horizon predictive control algorithm for uncertain systems with nonzero set points is proposed. For constant nonzero set points, models with uncertainty can be converted into an augmented incremental system through the use of integrators and the problem is transformed into a zero-state regulation problem for the incremental system. But the original constraints on inputs are converted into constraints on the sum of control inputs at each time Instants, which have not been dealt in earlier constrained robust receding horizon control problems. Recursive state bounding technique and worst case minimizing strategy developed in earlier works are applied to the augmented incremental system to yield an of set error free controller. The resulting algorithm is formulated so that it can be solved using LP.

  • PDF

Structural Design of Sliding Mode Controllers Using Robust Inernal-Loop Compensator (강인 내부루프 보상기를 이용한 슬라이딩 모드 제어기의 구조적 설계)

  • Kim, Bong-Keun;Chung, Wan-Kyun
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.7 no.4
    • /
    • pp.351-361
    • /
    • 2001
  • In this paper, a generalized framework called as robust internal-loop compensator(RIC) is presented, and by using this, a structural design method of sliding of sliding mode controller is proposed. First, a general sliding mode controller is derived and a stabilizing control input is designed based on Lyapunov redesign for the system in the presence of uncertainty and disturbance. And adopting the internal model following control, RIC is proposed. Next, using the structural characteristics of the proposed RIC, disturbance attenuation characteristics are analyzed and the performance of the closed-loop system is predicted. Through this analysis, it is shown that if the control gain of RIC is increased by N times, the magnitude of error is reduced to its 1/N. the proposed method is verified through experiments using a high-precision positioning system and the performance is evaluated.

  • PDF

Economic Valuation of R&D Programs with Strategic Flexibility (전략적 유연성을 고려한 연구개발사업의 경제성 평가: 이론 및 사례 분석)

  • Hwang, Seok-Won;Jeong, Jong-Uk
    • Journal of Technology Innovation
    • /
    • v.14 no.3
    • /
    • pp.237-261
    • /
    • 2006
  • Under circumstances with increasing uncertainty, strategic flexibility has become an essential point on which my R&D management system should be based. Unfortunately the present R&D management system for government sponsored R&D programs cannot be said to be so flexible to adapt appropriately to various threatens such as technological failure, a severe change in competition environment, and so on. In this paper a new scheme for R&D planning and economic assessment with strategic flexibility is suggested and applied to a real R&D program. In the newly suggested R&D management system, economic valuation based on real option theory is performed for various alternative scenarios which have different strategic scheme for R&D process each and the result of the assessment is fed back to R&D planning to choose more superior strategic scheme. Introducing strategic flexibility into R&D planning and economic assessment, the value of R&D project could be remarkably enhanced.

  • PDF

Damage Assessment of RC Bridge Using Neural-Fuzzy System (퍼지신경망을 이용한 철근콘크리트 교량의 손상도 평가)

  • Seong, Young-Joon;Kim, Ki- Bong
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.3 no.4
    • /
    • pp.129-137
    • /
    • 1999
  • Assessment of structural damage is a complex subject imbued with uncertainty and vagueness. This complexity arises from the use of subjective opinion and imprecise numerical data. Recently several active researches have been performed using new methods such as neural network approach or on-line damage detection. In this paper, Damage assessment (diagnosis) of the concrete bridges is studied by a new approach utilizing a neural fuzzy system that combined a neural network and a fuzzy logic. By applying this system to actual in-service bridges, it has been verified that the neural fuzzy method is effective for the bridge diagnosis.

  • PDF

A Study on Obstacle Avoidance Technology of Autonomous Treveling Robot Based on Ultrasonic Sensor (초음파센서 기반 자율주행 로봇의 장애물 회피에 관한 연구)

  • Hwang, Won-Jun
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.18 no.1
    • /
    • pp.30-36
    • /
    • 2015
  • This paper presents the theoretical development of a complete navigation problem of a nonholonomic mobile robot by using ultrasonic sensors. To solve this problem, a new method to computer a fuzzy perception of the environment is presented, dealing with the uncertainties and imprecision from the sensory system and taking into account nonholonomic constranits of the robot. Fuzzy perception, fuzzy controller are applied, both in the design of each reactive behavior and solving the problem of behavior combination, to implement a fuzzy behavior-based control architecture. The performance of the proposed obstacle avoidance robot controller in order to determine the exact dynamic system modeling system that uncertainty is difficult for nomadic controlled robot direction angle by ultrasonic sensors throughout controlled performance tests. In additionally, this study is an in different ways than the self-driving simulator in the development of ultrasonci sensors and unmanned remote control techniques used by the self-driving robot controlled driving through an unmanned remote controlled unmanned realize the performance of factory antomation.

An Access Control Based Privacy Protection Model in ID Management System (ID관리시스템의 접근통제기반 프라이버시 보안모델)

  • Choi Hyang-Chang;Noh Bong-Nam;Lee Hyung-Hyo
    • Journal of Internet Computing and Services
    • /
    • v.7 no.1
    • /
    • pp.1-16
    • /
    • 2006
  • The vulnerability of privacy in the Identity Management System (IMS) is the most pressing concern of ordinary users. Uncertainty about privacy keeps many users away from utilization of IMS. Therefore, this paper proposes an access-control oriented privacy model for IMS. The proposed model protects privacy using access control techniques with privacy policies in a single circle of trust. We address characteristics of the components of for the proposed model and describe access control procedures. After that, we show the architecture of privacy enforcement and XML-based schema for privacy policies.

  • PDF

Development of an Automatic Evaluation System for the Precision Analysis of Potential Transformer Burden Characteristics (전압변성기용 부담특성 정밀분석용 자동평가시스템의 개발)

  • Kwon, Sung-Won;Kim, Mun-Seog;Jung, Jae Kap;Lee, Sung-Ha;Kim, Yung Soo
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.54 no.10
    • /
    • pp.457-464
    • /
    • 2005
  • Both ratio error and phase angle error in potential transformer(PT) are critically affected by used burden, connected in parallel to the secondary terminal of the PT. Thus precise measurement of burden value is very important for the evaluation of PT An automatic measurement system has been developed for the measurement of burden value and power factor of a burden. The ac voltage, current and power of the burden are measured precisely, and the burden value and power factor were calculated from these measured values. The resistance and inductance values of the tested burden are also calculated. The overall measurement uncertainties are calculated and reported with the burden value and power factor. The best measurement uncertainty for the burden measurement with the developed automatic measurement system was estimated to be 0.5 $\%$.

A Fault Diagnostic Expert System for Silicone Oil-filled Transformer Using Dissolved Gas Analysis (유중가스분석법을 이용한 실리콘 유입변압기 고장진단 전문가 시스템)

  • Moon, Jong-Fil;Kim, Jae-Chul;Choi, Joon-Ho;Jun, Young-Jae;Kim, Oun-Seok
    • Proceedings of the KIEE Conference
    • /
    • 2001.11b
    • /
    • pp.374-376
    • /
    • 2001
  • In this paper, we developed the fault diagnostic expert system of silicone-immersed transformer using dissolved gas analysis. The knowledge base module consists of the knowledge using the rule: if Then . The inference engine uses the fuzzy rule for the management of uncertainty of the boundary and rule and derivate the Belief and Plausibility of the normality and fault using Dempster-Shafer theory. The expert system is connected to the database and it can manages the history of gas-data of the transformer.

  • PDF