What can systems and control theory do for agricultural science?

Abstract: While many professionals with a background in agricultural and bio-resource sciences work with models, only few have been exposed to systems and control theory. The purpose of this paper is to elucidate a selection of methods from systems theory that can be beneficial to quantitative agricultural science. The state space representation of a dynamical system is the corner stone in the mainstream of systems theory. It is not well known in agro-modelling that linearization followed by evaluation of eigenvalues and eigenvectors of the system matrix is useful to obtain dominant time constants and dominant directions in state space, and offers opportunities for science-based model reduction. The continuous state space description is also useful in deriving truly equivalent discrete time models, and clearly shows that parameters obtained with discrete models must be interpreted with care when transferred to another model code environment. Sensitivity analysis of dynamic models reveals that sensitivity is time and input dependent. Identifiability and sensitivity are essential notions in the design of informative experiments, and the idea of persistent excitation, leading to dynamic experiments rather than the usual static experiments can be very beneficial. A special branch of systems theory is control theory. Obviously, control plays an important part in agricultural and bio-systems engineering, but it is argued that also agronomists can profit from notions from the world of control, even if practical control options are restricted to alleviating growth limiting conditions, rather than true crop control. The most important is the idea of reducing uncertainty via feed-back. On the other hand, the systems and control community is challenged to do more to address the problems of real life, such as spatial variability, measurement delays, lacking data, environmental stochasticity, parameter variability, unavoidable model uncertainty, discrete phenomena, variable system structures, the interaction of technical ad living systems, and, indeed, the study of the functioning of life itself

Challenges and opportunities of low or zero carbon building: prospects of business models

Papers from the Designated Session TG66 - Energy and the Built EnvironmentCIB Publication 382: Selected papers presented at the CIB World Building Congres Construction and Society, Brisbane 5-9 May 2013There is an emerging consensus amongst governments, business sectors and civil societies regarding the urgent need to address the multiple challenges of climate change, environmental pollution, resource depletion and economic instability. The building and construction sector has been identified with the most opportunities for cost-effectively reducing carbon emissions. However, although business opportunities have been identified for low or zero carbon building (L/ZCB), L/ZCBs are generally perceived as more expensive and challenging than conventional buildings. Also, L/ZCBs are often addressed solely from their technological and environmental perspectives, while important economic and sociocultural aspects have been overlooked or examined implicitly. This paper aims to contribute to the knowledge of the challenges and opportunities of L/ZCB in a systems manner, and to explore how business models can help construction organisations address the former and maximise the latter. The research was carried out through the combination of a comprehensive literature review and case study with a large construction organisation which played a significant role in the UK and internationally. The examination of the challenges and opportunities employed the PESTEL analysis framework (Political, Economic, Sociocultural, Technological, Environmental and Legal). The case study included a desk study, observations, meetings and personal interviews with senior business and sustainability managers of the company. The results suggest the imperative role of business models for L/ZCB developments. Establishing and innovating business models were considered to present an opportunity for the company to sharpen their competitive edge in the market. A wide take-up of business models of L/ZCBs among construction firms was perceived to fit well the building industry's socio-technical system in addressing the multiple challenges.published_or_final_versio

ISLANDING DETECTION FOR GRID-CONNECTED DISTRIBUTED GENERATION SYSTEMS USING CONVOLUTIONAL NEURAL NETWORK

In the world today the lack of adequate supply of electricity is still a major problem especially in developing and underdeveloped countries. The global electrification rate is put at 75% and this figure has to go up in the coming years in other to promote sustainable development and eliminate world poverty. Distributed generation (DG) integration with the grid has been increasing worldwide due to the advantages it can provide to the electrical power systems, such as the possibility of reducing transmission and distribution losses, environmental benefits, the increase in the reliability of the power supply and the deferral of transmission and distribution investments. This makes it a suitable mechanism to improve electrification rate all over the world. Unintentional islanding is a major technical challenge that bedevils this system. Some researchers have developed islanding detection models to detect islanding and regard all other events that take place while the grid is still connected as Non-Islanding events while others have developed islanding detection models to detect islanding as well as identify Nonislanding disturbances when they occur (Islanding and Non-Islanding disturbance detection). Both system types are developed in this research. This research presents image-based islanding detection models using convolutional neural network. These models utilize scalogram images obtained from the aggregated phase voltages at point of common coupling (PCC). Therefore the models utilize the PCC voltage as the islanding detection parameter. The power system, islanding, and non-islanding events are simulated in MATLAB, wavelet transform is applied to the voltage signals obtained from the PCC for the different events to obtain the scalogram representation of the event. In both models developed a portion of this image data generated is used to train the classifier while the other part is used to test the classifier. The immunity of the developed models to noise is also investigated, the noise introduced did not have an adverse effect on the models. The results obtained from the simulation proves the ability of the proposed classifiers to detect islanding. The proposed models compare favourably with existing techniques and methods. For the first model, detection accuracy of 99.83% was obtained while for the second system detection accuracy of 99.2% was obtained

Annual Report Of the State Geologist, 1991

Since 1892, the Iowa Geological and Water Survey (IGWS) has provided earth, water, and mapping science to all Iowans. We collect and interpret information on subsurface geologic conditions, groundwater and surface water quantity and quality, and the natural and built features of our landscape. This information is critical for:Predicting the future availability of economic water supplies and mineral resources. Assuring proper function of waste disposal facilities.Delineation of geologic hazards that may jeopardize property and public safety. Assessing trends and providing protection of water quality and soil resources. Applied technical assistance for economic development and environmental stewardship. Our goal: Providing the tools for good decision making to assure the long-term vitality of Iowa’s communities, businesses, and quality of life. Information and technical assistance are provided through web-based databases, comprehensive Geographic Information System (GIS) tools, predictive groundwater models, and watershed assessments and improvement grants. The key service we provide is direct assistance from our technical staff, working with Iowans to overcome real-world challenges. This report describes the basic functions of IGWS program areas and highlights major activities and accomplishments during calendar year. More information on IGWS is available at http://www.igsb.uiowa.edu/

Annual Report Of the State Geologist, 1971, Vol. 42

Since 1892, the Iowa Geological and Water Survey (IGWS) has provided earth, water, and mapping science to all Iowans. We collect and interpret information on subsurface geologic conditions, groundwater and surface water quantity and quality, and the natural and built features of our landscape. This information is critical for:Predicting the future availability of economic water supplies and mineral resources. Assuring proper function of waste disposal facilities.Delineation of geologic hazards that may jeopardize property and public safety. Assessing trends and providing protection of water quality and soil resources. Applied technical assistance for economic development and environmental stewardship. Our goal: Providing the tools for good decision making to assure the long-term vitality of Iowa’s communities, businesses, and quality of life. Information and technical assistance are provided through web-based databases, comprehensive Geographic Information System (GIS) tools, predictive groundwater models, and watershed assessments and improvement grants. The key service we provide is direct assistance from our technical staff, working with Iowans to overcome real-world challenges. This report describes the basic functions of IGWS program areas and highlights major activities and accomplishments during calendar year. More information on IGWS is available at http://www.igsb.uiowa.edu/

Annual Report Of the State Geologist, 1974, Vol. 45

Since 1892, the Iowa Geological and Water Survey (IGWS) has provided earth, water, and mapping science to all Iowans. We collect and interpret information on subsurface geologic conditions, groundwater and surface water quantity and quality, and the natural and built features of our landscape. This information is critical for:Predicting the future availability of economic water supplies and mineral resources. Assuring proper function of waste disposal facilities.Delineation of geologic hazards that may jeopardize property and public safety. Assessing trends and providing protection of water quality and soil resources. Applied technical assistance for economic development and environmental stewardship. Our goal: Providing the tools for good decision making to assure the long-term vitality of Iowa’s communities, businesses, and quality of life. Information and technical assistance are provided through web-based databases, comprehensive Geographic Information System (GIS) tools, predictive groundwater models, and watershed assessments and improvement grants. The key service we provide is direct assistance from our technical staff, working with Iowans to overcome real-world challenges. This report describes the basic functions of IGWS program areas and highlights major activities and accomplishments during calendar year. More information on IGWS is available at http://www.igsb.uiowa.edu/

Annual Report Of the State Geologist, 1966, Vol. 39

Since 1892, the Iowa Geological and Water Survey (IGWS) has provided earth, water, and mapping science to all Iowans. We collect and interpret information on subsurface geologic conditions, groundwater and surface water quantity and quality, and the natural and built features of our landscape. This information is critical for:Predicting the future availability of economic water supplies and mineral resources. Assuring proper function of waste disposal facilities.Delineation of geologic hazards that may jeopardize property and public safety. Assessing trends and providing protection of water quality and soil resources. Applied technical assistance for economic development and environmental stewardship. Our goal: Providing the tools for good decision making to assure the long-term vitality of Iowa’s communities, businesses, and quality of life. Information and technical assistance are provided through web-based databases, comprehensive Geographic Information System (GIS) tools, predictive groundwater models, and watershed assessments and improvement grants. The key service we provide is direct assistance from our technical staff, working with Iowans to overcome real-world challenges. This report describes the basic functions of IGWS program areas and highlights major activities and accomplishments during calendar year. More information on IGWS is available at http://www.igsb.uiowa.edu/

Annual Report Of the State Geologist, 1994

Since 1892, the Iowa Geological and Water Survey (IGWS) has provided earth, water, and mapping science to all Iowans. We collect and interpret information on subsurface geologic conditions, groundwater and surface water quantity and quality, and the natural and built features of our landscape. This information is critical for:Predicting the future availability of economic water supplies and mineral resources. Assuring proper function of waste disposal facilities.Delineation of geologic hazards that may jeopardize property and public safety. Assessing trends and providing protection of water quality and soil resources. Applied technical assistance for economic development and environmental stewardship. Our goal: Providing the tools for good decision making to assure the long-term vitality of Iowa’s communities, businesses, and quality of life. Information and technical assistance are provided through web-based databases, comprehensive Geographic Information System (GIS) tools, predictive groundwater models, and watershed assessments and improvement grants. The key service we provide is direct assistance from our technical staff, working with Iowans to overcome real-world challenges. This report describes the basic functions of IGWS program areas and highlights major activities and accomplishments during calendar year. More information on IGWS is available at http://www.igsb.uiowa.edu/

GIS based modeling using Analytic Hierarchy Process (AHP) for optimization of landfill site selection of Rohtak city, Haryana (India)

Landfills are the most common method for the disposal of municipal solid waste the world over, as well as in India due to their low technical and economic requirements. The selection of an appropriate site for the establishment of a landfill is a complex process because it must combine social, environmental and technical parameters. The scientific selection of landfill site is based on several diverse criteria (Land Use and Land Cover, ground water table depth, soil permeability, surface water, roads distance, slop etc) and regulations. The study presents the selection of a site for the establishment of a landfill based on several criteria using geographic information system (GIS) based site suitability modeling and analytical hierarchy process (AHP). Site suitability modeling was implemented using Boolean and Index overlay models. Each criterion and sub criteria was evaluated with the aid of AHP to assign a relative weightage in the index overlay model. Rules and criteria’s set by Central Pollution Control Board (CPCB) and Central Public Health and Environmental Engineering Organisation (CPHEEO) were implemented through Boolean model. The combination of the results of the two models generated a map with several suitable sites. Further selection was done on basis of the size requirement of the site, to handle Municipal solid waste (MSW) for next ten years. Two sites having the maximum suitability and also fulfilling the size requirement were shortlisted. Final selection from the two sites was done by a field survey of the sites. Finally the site B was selected on the basis of field survey which revealed it being better on account of certain factors discussed and social acceptability

Annual Report Of the State Geologist, 1993

Since 1892, the Iowa Geological and Water Survey (IGWS) has provided earth, water, and mapping science to all Iowans. We collect and interpret information on subsurface geologic conditions, groundwater and surface water quantity and quality, and the natural and built features of our landscape. This information is critical for:Predicting the future availability of economic water supplies and mineral resources. Assuring proper function of waste disposal facilities.Delineation of geologic hazards that may jeopardize property and public safety. Assessing trends and providing protection of water quality and soil resources. Applied technical assistance for economic development and environmental stewardship. Our goal: Providing the tools for good decision making to assure the long-term vitality of Iowa’s communities, businesses, and quality of life. Information and technical assistance are provided through web-based databases, comprehensive Geographic Information System (GIS) tools, predictive groundwater models, and watershed assessments and improvement grants. The key service we provide is direct assistance from our technical staff, working with Iowans to overcome real-world challenges. This report describes the basic functions of IGWS program areas and highlights major activities and accomplishments during calendar year. More information on IGWS is available at http://www.igsb.uiowa.edu/