Monitoring: An Environmental State Estimation Problem

1974 ◽  
Vol 96 (3) ◽  
pp. 363-365 ◽  
Author(s):  
J. W. Brewer ◽  
S. F. Moore
Keyword(s):  
Water Quality ◽  
Spatial Distribution ◽  
System Design ◽  
Minimum Cost ◽  
Management Problem ◽  
Filter Theory ◽  
Monitor Synthesis ◽  
On Line ◽  
Measurement Devices ◽  
The Cost

A monitor is defined to be an estimator which minimizes the cost of taking measurements and which, simultaneously, meets constraints on accuracy. It is anticipated that the development of a monitor theory will facilitate environmental-technological system design. The authors propose that monitor synthesis can be divided into two subproblems. The “design problem” is to select the variables for measurement, to select the measurement devices, and to select the spatial distribution of the devices. The “management problem” is to select, on line, the type and sequencing of measurements. The note concludes with a simulated application of filter theory to the management of a water quality monitor. It is demonstrated that a suboptimal minimum cost monitor is, thereby, synthesized by the proper sequencing of costly measurements.

A Discussion on recent advances in heavy electrical plant - Future developments in the control of power systems

1973 ◽  
Vol 275 (1248) ◽  
pp. 243-253
Keyword(s):  
Power Systems ◽  
Minimum Cost ◽  
Constant Voltage ◽  
Present Position ◽  
Future Developments ◽  
Operational Characteristics ◽  
On Line ◽  
Computer Based ◽  
The Cost ◽  
And Control

The basic requirement of the control system is to ensure the supply of electric power at constant voltage and frequency exactly in accordance with the instantaneous demand. Its design is dominated by ( a ) the characteristics of the consumers’ demand; ( b ) the provision of a reliable supply, even under fault conditions, at minimum cost; ( c ) the technical and operational characteristics of a mixture of fossil-fired, nuclear and hydro generators; ( d )an assessment of the benefits to be gained and the cost of implementation. Large modern generating units are complex and their characteristics and those of the transmission system are such as to increase the difficulties of operation and control beyond the unaided capabilities of hum an operators. Automatic aids, many of them computer-based, are being used increasingly. The paper reviews the present position and indicates how advances in control technology could lead to on-line control of the system at acceptable cost.

A generalized fuzzy cost efficiency model

2020 ◽  
Vol 54 (6) ◽  
pp. 1775-1791
Author(s):  
Nazila Aghayi ◽  
Samira Salehpour
Keyword(s):  
Cost Efficiency ◽  
Minimum Cost ◽  
Extensive Literature ◽  
Data Envelopment ◽  
Fuzzy Environment ◽  
Decision Making Unit ◽  
Production Possibility Set ◽  
Fuzzy Cost ◽  
The Cost ◽  
Generalized Cost

The concept of cost efficiency has become tremendously popular in data envelopment analysis (DEA) as it serves to assess a decision-making unit (DMU) in terms of producing minimum-cost outputs. A large variety of precise and imprecise models have been put forward to measure cost efficiency for the DMUs which have a role in constructing the production possibility set; yet, there’s not an extensive literature on the cost efficiency (CE) measurement for sample DMUs (SDMUs). In an effort to remedy the shortcomings of current models, herein is introduced a generalized cost efficiency model that is capable of operating in a fuzzy environment-involving different types of fuzzy numbers-while preserving the Farrell’s decomposition of cost efficiency. Moreover, to the best of our knowledge, the present paper is the first to measure cost efficiency by using vectors. Ultimately, a useful example is provided to confirm the applicability of the proposed methods.

Main approaches to estimating the cost of shareholder equity of oil and gas producers

2020 ◽  
Vol 26 (3) ◽  
pp. 685-697
Author(s):  
O.V. Shimko
Keyword(s):  
Oil And Gas ◽  
Oil Prices ◽  
Minimum Cost ◽  
Free Cash Flow ◽  
Annual Reports ◽  
Comparative Approach ◽  
Economic Activities ◽  
Advantages And Disadvantages ◽  
Oil And Gas Producers ◽  
The Cost

Subject. The study analyzes generally accepted approaches to assessing the value of companies on the basis of financial statement data of ExxonMobil, Chevron, ConocoPhillips, Occidental Petroleum, Devon Energy, Anadarko Petroleum, EOG Resources, Apache, Marathon Oil, Imperial Oil, Suncor Energy, Husky Energy, Canadian Natural Resources, Royal Dutch Shell, Gazprom, Rosneft, LUKOIL, and others, for 1999—2018. Objectives. The aim is to determine the specifics of using the methods of cost, DFC, and comparative approaches to assessing the value of share capital of oil and gas companies. Methods. The study employs methods of statistical analysis and generalization of materials of scientific articles and official annual reports on the results of financial and economic activities of the largest public oil and gas corporations. Results. Based on the results of a comprehensive analysis, I identified advantages and disadvantages of standard approaches to assessing the value of oil and gas producers. Conclusions. The paper describes pros and cons of the said approaches. For instance, the cost approach is acceptable for assessing the minimum cost of small companies in the industry. The DFC-based approach complicates the reliability of medium-term forecasts for oil prices due to fluctuations in oil prices inherent in the industry, on which the net profit and free cash flow of companies depend to a large extent. The comparative approach enables to quickly determine the range of possible value of the corporation based on transactions data and current market situation.

Applying Probabilistic Water Quality Standards in River Basin Water Quality Optimization Models

1974 ◽  
Vol 9 (1) ◽  
pp. 25-29
Author(s):  
M. B. Bayer
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Minimum Cost ◽  
Water Quality Standards ◽  
Quality Optimization ◽  
Basin Water ◽  
Do Concentration ◽  
Water Quality Models

Abstract This paper describes a method of applying probabilistic DO (dissolved oxygen) and BOD (biochemical oxygen demand) standards in river basin water quality models. Maximum likelihood estimators for the DO and BOD concentrations variances for each reach are used to obtain a lower bound for BOD so that the probability of violating specified DO and BOD standards is less than Θ per cent in any reach. These boundary values for DO and BOD concentrations are incorporated into a nonlinear water quality optimization model for finding the minimum cost set of wastewater treatment plant efficiencies required to meet DO and BOD standards. The method also provides the minimum DO concentration and the maximum BOD concentration which may be expected to occur 1-Θ of the time for any reach.

What's it Worth? Improving Surface Water Quality

1999 ◽  
Vol 40 (10) ◽  
pp. 153-159 ◽  
Author(s):  
D. H. Newsome ◽  
C. D. Stephen
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Surface Water Quality ◽  
Control Measures ◽  
Benefit Analysis ◽  
The Cost

Many countries are investing in measures to improve surface water quality, but the investment programmes for so doing are increasingly becoming subject to cost-benefit analysis. Whilst the cost of control measures can usually be determined for individual improvement schemes, there are currently no established procedures for valuing the benefits attributable to improved surface water quality. The paper describes a methodology that has been derived that now makes this possible.

A claims problem approach to the cost allocation of a minimum cost spanning tree

2021 ◽  
Author(s):  
José-Manuel Giménez-Gómez ◽  
Josep E. Peris ◽  
Begoña Subiza
Keyword(s):  
Spanning Tree ◽  
Cost Allocation ◽  
Minimum Cost ◽  
Claims Problem ◽  
The Cost

scholarly journals Classification of groundwater suitability for irrigation purposes using a comprehensive approach based on the AHP and GIS techniques in North Kurdufan Province, Sudan

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Elsiddig Eldaw ◽  
Tao Huang ◽  
Adam Khalifa Mohamed ◽  
Yahaya Mahama
Keyword(s):  
Water Quality ◽  
Spatial Distribution ◽  
Groundwater Quality ◽  
Irrigation Water ◽  
Research Effort ◽  
Sodium Absorption ◽  
Irrigation Water Quality ◽  
Middle Income ◽  
Sodium Absorption Ratio ◽  
Deep Aquifers

AbstractDeterioration of groundwater quality due to drastic human interventions is rising at an alarming rate particularly in lower- and middle-income countries. Yet, limited research effort has been devoted to monitoring and ascertaining groundwater quality. The present study develops a comprehensive irrigation water quality index (IWQI) for rating water quality of shallow and deep aquifers in North Kurdufan province, Sudan. The new approach is developed to overcome the deficiencies of the existing irrigation indices and coming up with a unified decision for classifying water quality for irrigation purposes. Because of these indices like permeability index (PI), sodium absorption ratio (SAR), etc., depending on specific elements, entirely subjective, as well as the great variations in their results, particularly when classifying water quality. Thus, IWQI is created based on eight indices that are generally used to evaluate irrigation water quality, plus three physicochemical parameters have been proven an impact on water quality. The analytic hierarchy process (AHP) is applied to minimize the subjectivity at assign parameter weights under multiple criteria decision analysis tools (MCDA). The spatial distribution of IWQI agrees with the spatial distribution of the most parameters. The results of our approach reveal that the majority of samples are suitable for irrigation uses for both aquifers except few wells in the confined aquifer. Also, noted that there are very variations in the irrigation indices results for classifying water quality. The comparison result showed that the new index robust, fair calculations and has best classifying of water quality.

Monitoring raw water quality and adjustment of treatment processes – experiences at the wahnbach reservoir

1998 ◽  
Vol 37 (2) ◽  
pp. 43-48 ◽  
Author(s):  
Oluf Hoyer ◽  
Helmut Schell
Keyword(s):  
Water Quality ◽  
Effective Control ◽  
Raw Water ◽  
Titration Method ◽  
Treatment Processes ◽  
On Line ◽  
Raw Water Quality

On-line monitoring of turbidity allows effective control of source and finished water quality. Fundamentals for particle destabilisation and removal are outlined and the application of the charge titration method for optimal online adjustment of the flocculant dosage is presented.

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