• Title/Summary/Keyword: uncertain environment

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A direction of warfighting experiments for a scientific combat Development (과학적 전투발전을 위한 전투실험 발전 방향)

  • Chung, Choon-Il;Lee, Myeong-Woo
    • Journal of National Security and Military Science
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    • s.5
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    • pp.351-392
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    • 2007
  • Combat Development is process of studying and developing concept, doctrine, weapon systems, organization and training for the improvement of combat capability to be ready present and future warfare. The combat development domain consists of 6 fields Doctrine, Organization, Material, Training, Personnel, and Facilities. The cornerstones of combat development are "How to prepare" and "How to fight" in the future warfare. ROK- TRADOC(Republic of Korea Army Training and Doctrine Command) has implemented combat development that applies CBRS (Concept-Based Requirements System) and "Vision - Capstone concept - operating and functional concept - FOC(Future Operational Capabilities) Requirements". To prepare for the possibility or new types or wars in the future, the creation of new concept and system is essential. Though verification with various instruments, combat power can be secured and exhibited. Combat development by empirical mind estimation means that is no longer relevant.To prepare combat development based on scientific analysis, there is a need for powerful engineering analysis and verification, in order to prepare for uncertain and diverse future battlefield environments. In this thesis, warfighting experiment is essential ways and means to pursue the scientific combat development ; investigated tendency of combat development environment, and analyzed diversification aspects of possible future warfare. In conclusion, concept of campaign experiment and role is the conerstone of scientific combat development; and lays out the roadmap of all affecting components to its development.

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Relationship Among h Value, Membership Function, and Spread in Fuzzy Linear Regression using Shape-preserving Operations

  • Hong, Dug-Hun
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.8 no.4
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    • pp.306-311
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    • 2008
  • Fuzzy regression, a nonparametric method, can be quite useful in estimating the relationships among variables where the available data are very limited and imprecise. It can also serve as a sound methodology that can be applied to a variety of management and engineering problems where variables are interacting in an uncertain, qualitative, and fuzzy way. A close examination of the fuzzy regression algorithm reveals that the resulting possibility distribution of fuzzy parameters, which makes this technique attractive in a fuzzy environment, is dependent upon an h parameter value. The h value, which is between 0 and 1, is referred to as the degree of fit of the estimated fuzzy linear model to the given data, and is subjectively selected by a decision maker (DM) as an input to the model. The selection of a proper value of h is important in fuzzy regression, because it determines the range of the posibility ditributions of the fuzzy parameters. In this paper, we discuss the interdependent relationship among the h value, membership function shape, and the spreads of fuzzy parameters in fuzzy linear regression with fuzzy input-output using shape-preserving operations.

A Study on the Control of AC Servo Motor for Machine Tools Cartesian Coordinate Type Using Neural Network (신경회로망을 이용한 평면좌표형 공작기계 교류서보전동기의 제어에 관한 연구)

  • 김평호;백형래;정수복
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.1
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    • pp.49-56
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    • 2001
  • This paper presents a new approach to the problem based on neural network methods. Instead of using general controllers, neural networks PID control are used to control AC servo motor. The most popular and widely used control method in servo system control loops is PID type. PID controller has the features of simple structure, stability and reliability. But it has limitations in complex system control and can not remain above virtues under the conditions of parameters uncertain and environment uncertainties. AC servo motor controller is designed for drive of the cartesian coordinate type for machine tools.

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Adaptive Compensation Control of Vehicle Automatic Transmissions for Smooth Shift Transients Based on Intelligent Supervisor

  • Kim, Deok-Ho;Han, Jin-O;Sin, Byeong-Gwan;Lee, Gyu-Il
    • Journal of Mechanical Science and Technology
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    • v.15 no.11
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    • pp.1472-1481
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    • 2001
  • In this paper, an advanced shift controller that supervises the shift transients with adaptive compensation is presented. Modern shift control systems for vehicle automatic transmission are designe d to provide smooth transients for passengers' comfort and better component durability. In the conventional methods, lots of testing and calibration works have been done to tune gains of the controller, but it does not assure optimum shift quality at all times owing to system variations often caused by uncertainties in shifting hydraulic systems and external disturbances. In the proposed control scheme, an adaptive compensation controller with intelligent supervisor is implemented to achieve improved shift quality over the system variations. The control input pattern which generates clutch pressure commands in hydraulic actuating systems, is updated through a learning process to adjust for each subsequent shift based on continuous monitoring of shifting performance and environmental changes. The proposed algorithm is implemented and evaluated on the experimental test setup. Results from the experimental studies for several operation modes show both improved performance and adaptability of the proposed shift controller to uncertain changes of the shifting environment in vehicle power transmission systems.

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Sonar Map Construction for Autonomous Mobile Robots Using Data Association Filter (데이터 연관 필터를 이용한 자율이동로봇의 초음파지도 작성)

  • Lee Yu-Chul;Lim Jong-Hwan;Cho Dong-Woo
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.9
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    • pp.539-546
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    • 2005
  • This paper describes a method of building the probability grid map for an autonomous mobile robot using the ultrasonic DAF(data association filter). The DAF, which evaluates the association of each data with the rest and removes the data affected by the specular reflection effect, can improve the reliability of the data for the Probability grid map. This method is based on the evaluation of possibility that the acquired data are all from the same object. Namely, the data from specular reflection have very few possibilities of detecting the same object, so that they are excluded from the data cluster during the process of the DAF. Therefore, the uncertain data corrupted by the specular reflection and/or multi-path effect, are not used to update the probability map, and hence building a good quality of a grid map is possible even in a specular environment. In order to verify the effectiveness of the DAF, it was applied to the Bayesian model and the orientation probability model which are the typical ones of a grid map. We demonstrate the experimental results using a real mobile robot in the real world.

A study of Monolithic Design and Contemporary Architecture Space Constitution (모놀리틱디자인과 현대건축공간구성에 관한 연구)

  • Kim, Jun-Ho;Lee, Jung-Wook
    • Korean Institute of Interior Design Journal
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    • v.26 no.1
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    • pp.3-12
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    • 2017
  • In today's society, Monolithic expresses itself as a single featured work with a consistent exterior in the urban environment. In particular, such characteristics of the monolithic work have become increasingly influential in the modern society with the emergence of the minimalism. Monolithic architecture in modern has common feature which is maintaining simple construction format (Mass) with complicated and abundance space (Volume) inside. This simple architecture exterior leads new stimulus which is different from previous format and evokes unique sensibility and thoughts with monumental expressing. Uniformed exterior revealed thru purity of material builds up strong presence by itself. In contract with simple exterior, diverse space is expressed by consistent concept and process. Through this, it shows creating metaphorical space and space-oriented feature. We can interpret modern monolithic architecture as a sensation and alternative against Gestalt architecture in consequence of chasing clarity, visual stimulus and uncertain tendency only. It provides architectural experience by spatial imaginary and unexpected space development to users through exclusivetendency against outside and stressing un-private, we can evaluate its value as a space-oriented construction which helped us to think about space meaning in modern society.

A Method of Evaluating Profitability and Risk of Multiple Investments Applying Internal Rate of Return

  • Mizumachi, Tadahiro
    • Industrial Engineering and Management Systems
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    • v.9 no.2
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    • pp.121-130
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    • 2010
  • In today's uncertain economic environment, economic risk is inherent in making large investments on manufacturing facilities. It is, therefore, practically meaningful to divide investment over multiple periods, reducing the risk of investment. Then, the cash-flow over the entire planning horizon would comprise positive inflow and negative outflow. In this case, in general, evaluation by internal rate of return (IRR) is not feasible, because multiple IRRs are involved. This paper deals with a problem of evaluating profitability, as well as risk, of investment alternatives made in multiple times of investment over the entire horizon. Typically, an additional investment is required after the initial one, for expanding manufacturing capacity or other reasons. The paper pays attention to a unit cash-flow over two periods, decomposing the total cash-flow into a series of unit cash-flow patterns. It is easy to evaluate profitability of a unit cash-flow by using IRR. The total cash-flow can be decomposed into the series of two types of unit cash-flows: an investment type one (negative-positive) and the borrowing type one (positive-negative). This paper, therefore, proposes a method in which only the borrowing type unit cash-flow is eliminated in the series by converting total cash-flow using capital interest rate. Then, a unique IRR can be obtained and the profitability is evaluated. Thus, the paper extends the method of IRR so that it may help decision making in complicated cash-flow pattern observed in practice.

Rigidity Evaluation under Uncertainties for Multiple Investment Alternatives over Multiple Periods

  • Kono, Hirokazu;Mizumachi, Tadahiro
    • Industrial Engineering and Management Systems
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    • v.9 no.2
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    • pp.107-120
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    • 2010
  • In today's uncertain economic environment, the evaluation of safety for investment alternatives is of practical importance in manufacturing companies. This paper examines a method of quantitatively evaluating profitability and risk for multiple alternatives using the total-cost unit-cost domain. The paper assumes such factors as unit sales price, sales and production volume, unit variable cost, fixed cost, and yield for each alternative. The paper incorporates the relationship between production capacity and demand, distinguishing between cases of production capacity surplus and shortage for each year over the entire planning horizon. The paper investigates the case in which the values of each factor independently move in the direction of decreasing profit each year, and clarifies the procedure of comparing safety among multiple investment alternatives on a single consolidated total-cost unit-cost domain. The difficulty of the problem lies in the method of consolidating multiple total-cost unit-cost domains into a single domain since the combination of years of capacity surplus and shortage depends upon the change values in each factor under consideration. A systematic method of evaluating profitability as well as risk is presented, and the validity of the proposed method is verified using a numerical example.

An efficient optimization approach for wind interference effect on octagonal tall building

  • Kar, Rony;Dalui, Sujit Kumar;Bhattacharjya, Soumya
    • Wind and Structures
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    • v.28 no.2
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    • pp.111-128
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    • 2019
  • In this paper an octagon plan shaped building (study building) in presence of three square plan shaped building is subjected to boundary layer wind flow and the interference effects on the study building is investigated using Computational fluid dynamics. The variation of the pressure coefficients on different faces of the octagon building is studied both in isolated and interference conditions. Interference Factors (IF) are calculated for different faces of the study building which can be a powerful tool for designing similar plan shaped buildings in similar conditions. A metamodel of the IF, in terms of the distances among buildings is also established using Response Surface Method (RSM). This set of equations are optimized to get the optimum values of the distances where the IF is unity. An upstream Interference zone for this building setup and wind environment is established from these data. Uncertainty principle is also utilised to determine the optimum positions of the interfering buildings considering the uncertain nature of wind flow for minimum interference effect. The proposed procedure is observed to be computationally efficient in deciding optimum layout at buildings often required in city planning. The results show that the proposed RSM-based optimization approach captures the interference zone accurately with substantially less number of experiments.

A Study on Orientation and Position Control of Mobile Robot Based on Multi-Sensors Fusion for Implimentation of Smart FA (스마트팩토리 실현을 위한 다중센서기반 모바일로봇의 위치 및 자세제어에 관한 연구)

  • Dong, G.H;Kim, D.B.;Kim, H.J;Kim, S.H;Baek, Y.T;Han, S.H
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.2
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    • pp.209-218
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    • 2019
  • This study proposes a new approach to Control the Orientation and position based on obstacle avoidance technology by multi sensors fusion and autonomous travelling control of mobile robot system for implimentation of Smart FA. The important focus is to control mobile robot based on by the multiple sensor module for autonomous travelling and obstacle avoidance of proposed mobile robot system, and the multiple sensor module is consit with sonar sensors, psd sensors, color recognition sensors, and position recognition sensors. Especially, it is proposed two points for the real time implementation of autonomous travelling control of mobile robot in limited manufacturing environments. One is on the development of the travelling trajectory control algorithm which obtain accurate and fast in considering any constraints. such as uncertain nonlinear dynamic effects. The other is on the real time implementation of obstacle avoidance and autonomous travelling control of mobile robot based on multiple sensors. The reliability of this study has been illustrated by the computer simulation and experiments for autonomous travelling control and obstacle avoidance.