Integrated Control Concept Research Articles

Measure To Control Of Parasitic Infections of Swine in Commercial Farm

Parasitic infections cause significant losses to swine production in the farm system. Aim of our work is to presented measures to control parasitic infections at farms breeding swine. The basic measures that were developed and applied were: 1. Use the principles of good production and hygiene practices, 2. Management of the production process, 3. Parasitological diagnostics 4. Application of antiparasitic drugs 5. Strict compliance with biosecurity measures 6. General animal hygiene measures 7. Pest control and disinfection 8. Control of stray dogs and cats on the farm and control of birds 9. Removal of corpses 10. Removal of waste 11. Educational program. The application of this integrated control concept of parasite infection required systematic monitoring of infection on farms and slaughterhouses before and after the applied measures. During the control before the application of the measures, then six months later, the results obtained showed a reduction in the prevalence of parasitic infections by over 80%. Certainly, the complexity of the problem required the involvement of all relevant entities, primarily veterinary services, from farms to slaughterhouses.

Control Strategies for Daylight and Artificial Lighting in Office Buildings—A Bibliometrically Assisted Review

A significant proportion of the total energy consumption in office buildings is attributable to lighting. Enhancements in energy efficiency are currently achieved through strategies to reduce artificial lighting by intelligent daylight utilization. Control strategies in the field of daylighting and artificial lighting are mostly rule-based and focus either on comfort aspects or energy objectives. This paper aims to provide an overview of published scientific literature on enhanced control strategies, in which new control approaches are critically analysed regarding the fulfilment of energy efficiency targets and comfort criteria simultaneously. For this purpose, subject-specific review articles from the period between 2015 and 2020 and their research sources from as far back as 1978 are analysed. Results show clearly that building controls increasingly need to address multiple trades to achieve a maximum improvement in user comfort and energy efficiency. User acceptance can be highlighted as a decisive factor in achieving targeted system efficiencies, which are highly determined by the ability of active user interaction in the automatic control system. The future trend is moving towards decentralized control concepts including appropriate occupancy detection and space zoning. Simulation-based controls and learning systems are identified as appropriate methods that can play a decisive role in reducing building energy demand through integral control concepts.

An equilibrium-based learning approach with application to robotic fish

In this work, we extend the concept of integral control to equilibrium-based learning control. As far as the plant reaches an equilibrium that deviates from the reference, a learning mechanism will update the control action. The new control action will drive the plant output to reach a new equilibrium that is closer the reference set-point. By applying fixed point theorem, we can prove the convergence of the controlled equilibrium to the reference set-point exponentially, where the plant dynamics can be generically nonlinear and non-affine. The only prior information required is a non-singular input–output gradient of the stabilized plant. As a real-time application, the proposed control method is applied to motion control of a tail-actuated robotic fish. To facilitate the controller design, the dynamical model of the robotic fish is established based on Newton’s second law and Lighthill’s small amplitude model. In the end, both simulations and experiments are conducted to illustrate the effectiveness of the proposed learning approach.

Performance of Homeostatic Controller Motifs Dealing with Perturbations of Rapid Growth and Depletion.

An essential property of life is that cells and organisms have the ability to protect themselves against external disturbances/attacks by using homeostatic mechanisms. These defending mechanisms are based on negative feedback regulation and often contain additional features, such as integral control, where the integrated error between a controlled variable and its set-point is used to achieve homeostasis. Although the concept of integral control has its origin in industrial processes, recent findings suggest that biological systems are also capable of showing integral control. We recently described a basic set of negative feedback structures (controller motifs) where robust homeostasis is achieved against different but constant perturbations. As many perturbations in biology, such as infections, increase rapidly over time, we investigated how the different controller motifs equipped with different implementations of integral control perform in relation to rapidly changing perturbations, including exponential and hyperbolic changes. The findings show that the construction of an optimum biochemical controller design for time-dependent perturbations requires a certain match between the structure of the negative feedback loop, its signaling kinetics, and the kinetics of how integral control is implemented within the negative feedback loop.

Indifference Analysis: A Practical Method to Assess Uncertainty in IPM Decision Making

Since the publication of the integrated control concept ( Stern et al. 1959 ), integrated pest management (IPM) has been based upon the principle of rational decision making with knowledge of plant-pest interactions and economic tradeoffs. In addition, although the determination of economic-injury levels and other decision benchmarks have been extraordinarily helpful with the application of IPM principles, they often are fixed, when, in fact, the situation-specific circumstances require a more dynamic approach. Moreover, in situations for which preventive control measures are preferred or required, there has been little guidance for decision makers on how to quantify payoffs to their control options. This paper introduces an approach referred to as indifference analysis, a simple and straightforward practitioner approach to support decision making in IPM programs when outcomes are unknown. The concept is based upon a basic 2 × 2 payoff matrix of prospective financial outcomes for pest management decisions taken with uncertain outcomes. Two case studies are presented to illustrate the use of indifference analysis. For each case, an indifference point is determined that provides transparency regarding the relative financial risk of various management options, leading to insights for selecting tactics under uncertainty. This approach may enlighten decision makers in choosing their IPM practices when outcomes are unknown and uncertain.

Relevance of Traditional Integrated Pest Management (IPM) Strategies for Commercial Corn Producers in a Transgenic Agroecosystem: A Bygone Era?

The use of transgenic Bt maize hybrids continues to increase significantly across the Corn Belt of the United States. In 2009, 59% of all maize planted in Illinois was characterized as a "stacked" gene variety. This is a 40% increase since 2006. Stacked hybrids typically express one Cry protein for corn rootworm control and one Cry protein for control of several lepidopteran pests; they also feature herbicide tolerance (to either glyphosate or glufosinate). Slightly more than 50 years has passed since Vernon Stern and his University of California entomology colleagues published (1959) their seminal paper on the integrated control concept, laying the foundation for modern pest management (IPM) programs. To assess the relevance of traditional IPM concepts within a transgenic agroecosystem, commercial maize producers were surveyed at a series of meetings in 2009 and 2010 regarding their perceptions on their use of Bt hybrids and resistance management. Special attention was devoted to two insect pests of corn, the European corn borer and the western corn rootworm. A high percentage of producers who participated in these meetings planted Bt hybrids in 2008 and 2009, 97 and 96.7%, respectively. Refuge compliance in 2008 and 2009, as mandated by the U.S. Environmental Protection Agency (EPA), was 82 and 75.7%, respectively, for those producers surveyed. A large majority of producers (79 and 73.3% in 2009 and 2010, respectively) revealed that they would, or had, used a Bt hybrid for corn rootworm (Diabrotica virgifera virgifera LeConte) or European corn borer (Ostrinia nubilalis Hübner) control even when anticipated densities were low. Currently, the EPA is evaluating the long-term use of seed blends (Bt and non-Bt) as a resistance management strategy. In 2010, a large percentage of producers, 80.4%, indicated they would be willing to use this approach. The current lack of integration of management tactics for insect pests of maize in the U.S. Corn Belt, due primarily to the escalating use of transgenic Bt hybrids, may eventually result in resistance evolution and/or other unforeseen consequences.

In Focus: 50 years of the integrated control concept in arthropod IPM

In Focus: 50 years of the integrated control concept in arthropod IPM

Implementing principles of the integrated control concept 50 years later—current challenges in IPM for arthropod pests

Implementing principles of the integrated control concept 50 years later—current challenges in IPM for arthropod pests

Fifty years of the integrated control concept: the role of landscape ecology in IPM in San Joaquin valley cotton

In defining the integrated control concept, Stern, Smith, van den Bosch and Hagan described 'understanding the ecosystem' as a key underpinning of the concept. In following years, Stern and van den Bosch continued to refine and expand the role of the ecological landscape. They and their colleagues developed cultural practices that took advantage of this understanding to limit the need of pesticide intervention in cotton in the San Joaquin Valley during the 1960s and 1970s. Research and extension activities in the intervening years built upon those fundamental concepts using geospatial tools and analytical techniques to refine current understanding and develop ecological landscape level approaches to manage Lygus hesperus (Knight) in San Joaquin Valley cotton, Gossypium hirsutum (L.) and more recently G. barbadense (L.). The result has been a significant drop in insecticide use against L. hesperus, with less than one application per season during the 1990 s and early 2000s.

IPM for fresh-market lettuce production in the desert southwest: the produce paradox.

In the 'Integrated Control Concept', Stern et al. emphasized that, although insecticides are necessary for agricultural production, they should only be used as a last resort and as a complement to biological control. They argued that selective insecticide use should only be attempted after it has been determined that insect control with naturally occurring biotic agents is not capable of preventing economic damage. However, they concluded their seminal paper by emphasizing that integrated control will not work where natural enemies are inadequate or where economic thresholds are too low to rely on biological control. Thus, it is no surprise that insect control in high-value, fresh-market lettuce crops grown in the desert southwest have relied almost exclusively on insecticides to control a complex of mobile, polyphagous pests. Because lettuce and leafy greens are short-season annual crops with little or no tolerance for insect damage or contamination, biological control is generally considered unacceptable. High expectations from consumers for aesthetically appealing produce free of pesticide residues further forces vegetable growers to use chemical control tactics that are not only effective but safe. Consequently, scientists have been developing integrated pest management (IPM) programs for lettuce that are aimed at reducing the economic, occupational and dietary risks associated with chemical controls of the past. Most of these programs have drawn upon the integrated control concept and promote the importance of understanding the agroecosystem, and the need to sample for pest status and use action thresholds for cost-effective insect control. More recently, pest management programs have implemented newly developed, reduced-risk chemistries that are selectively efficacious against key pests. This paper discusses the influence that the integrated control concept, relative to zero-tolerance market standards and other constraints, has had on the adoption of pest management in desert lettuce crops.

Sampling plans, selective insecticides and sustainability: the case for IPM as ‘informed pest management’

Integrated Pest Management (IPM) is considered the central paradigm of insect pest management and is often characterized as a comprehensive use of multiple control tactics to reduce pest status while minimizing economic and environmental costs. As the principal precursor of IPM, the integrated control concept formulated the economic theory behind pest management decisions and specified an applied methodology for carrying out pest control. Sampling, economic thresholds and selective insecticides were three of the critical elements of that methodology and are now considered indispensable to the goals of IPM. We examine each of these elements in the context of contemporaneous information as well as accumulated experience and knowledge required for their skillful implementation in an IPM program. We conclude that while IPM is principally about integrating control tactics into an effective and sustainable approach to pest control, this overarching goal can only be achieved through well-trained practitioners, knowledgeable of the tenets conceived in the integrated control concept that ultimately yield informed pest management.

Fifty years of the integrated control concept: moving the model and implementation forward in Arizona

Fifty years ago, Stern, Smith, van den Bosch and Hagen outlined a simple but sophisticated idea of pest control predicated on the complementary action of chemical and biological control. This integrated control concept has since been a driving force and conceptual foundation for all integrated pest management (IPM) programs. The four basic elements include thresholds for determining the need for control, sampling to determine critical densities, understanding and conserving the biological control capacity in the system and the use of selective insecticides or selective application methods, when needed, to augment biological control. Here we detail the development, evolution, validation and implementation of an integrated control (IC) program for whitefly, Bemisia tabaci (Genn.), in the Arizona cotton system that provides a rare example of the vision of Stern and his colleagues. Economic thresholds derived from research-based economic injury levels were developed and integrated with rapid and accurate sampling plans into validated decision tools widely adopted by consultants and growers. Extensive research that measured the interplay among pest population dynamics, biological control by indigenous natural enemies and selective insecticides using community ordination methods, predator:prey ratios, predator exclusion and demography validated the critical complementary roles played by chemical and biological control. The term ‘bioresidual’ was coined to describe the extended environmental resistance from biological control and other forces possible when selective insecticides are deployed. The tangible benefits have been a 70% reduction in foliar insecticides, a >$200 million saving in control costs and yield, along with enhanced utilization of ecosystem services over the last 14 years. Published in 2009 by John Wiley & Sons, Ltd.

The integrated control concept and its relevance to current integrated pest management in California fresh market grapes

The foundation of an integrated pest management program involves valid treatment thresholds, accurate and simple monitoring methods, effective natural controls, selective pesticides and trained individuals who can implement the concept. The Integrated Control Concept written by Stern, Smith, van den Bosch and Hagen elucidated each of these points in an alfalfa ecosystem. Alfalfa hay (Medicago sativa L.) has a low per acre value, requires little hand labor and is primarily marketed in the USA. In contrast, fresh market table grape (Vitis vinifera L.) has a high per acre value, requires frequent hand labor operations, suffers unacceptable cosmetic damage and is marketed throughout both the USA and the world. Each of the components of a working IPM program is present in table grape production. Marketing grapes to foreign countries presents special problems with pests considered invasive and where residue tolerances for some selective insecticides are lacking. However, fresh market grape farmers are still able to deal with these special problems and utilize an IPM program that has resulted in a 42% reduction in broad-spectrum insecticide use from 1995 to 2007.

The Control of the Controller: Molecular Mechanisms for Robust Perfect Adaptation and Temperature Compensation

Organisms have the property to adapt to a changing environment and keep certain components within a cell regulated at the same level (homeostasis). “Perfect adaptation” describes an organism's response to an external stepwise perturbation by regulating some of its variables/components precisely to their original preperturbation values. Numerous examples of perfect adaptation/homeostasis have been found, as for example, in bacterial chemotaxis, photoreceptor responses, MAP kinase activities, or in metal-ion homeostasis. Two concepts have evolved to explain how perfect adaptation may be understood: In one approach (robust perfect adaptation), the adaptation is a network property, which is mostly, but not entirely, independent of rate constant values; in the other approach (nonrobust perfect adaptation), a fine-tuning of rate constant values is needed. Here we identify two classes of robust molecular homeostatic mechanisms, which compensate for environmental variations in a controlled variable's inflow or outflow fluxes, and allow for the presence of robust temperature compensation. These two classes of homeostatic mechanisms arise due to the fact that concentrations must have positive values. We show that the concept of integral control (or integral feedback), which leads to robust homeostasis, is associated with a control species that has to work under zero-order flux conditions and does not necessarily require the presence of a physico-chemical feedback structure. There are interesting links between the two identified classes of homeostatic mechanisms and molecular mechanisms found in mammalian iron and calcium homeostasis, indicating that homeostatic mechanisms may underlie similar molecular control structures.

The contribution of conservation biological control to integrated control of Bemisia tabaci in cotton

Integrated control systems are based on the complimentary contribution of chemical and biological control fostered by conservation of natural enemies. Yet, in the 50years since the integrated control concept [ICC] [Stern, V.M., Smith, R.F., van den Bosch, R., Hagen, K.S., 1959. The integrated control concept. Hilgardia 29, 81–101] was introduced there are few operational programs and even fewer attempts to analyze the mechanisms that allow chemical and biological control to act in concert. The dearth of demonstrable evidence for the ICC has eroded the credibility of biological control and its usage in operational IPM plans. We used in situ life tables within an experimental design to measure and compare the contribution and interaction of biological control and insecticides as tactical components within three pest management systems for Bemisia tabaci (Gennadius) in cotton. Insecticides were the key factor immediately following applications of broad-spectrum materials or one of two selective insect growth regulators (IGRs), and this mortality replaced that provided by natural enemies. Two to six weeks later, however, mortality from natural enemies, primarily predation, in the IGR regimes rebounded to the high levels observed in untreated controls and became the key factor. Mortality from natural enemies remained depressed in the broad-spectrum insecticide regime. Single IGR applications were sufficient to suppress B. tabaci populations throughout the season, while up to five broad-spectrum applications were needed to achieve comparable control. The chemical residual of IGRs was limited to several weeks, demonstrating a key role for mortality from conserved natural enemies that extended the control interval. This “bioresidual” allows for long-term, commercially-acceptable pest suppression following the use of selective insecticides. We provide a rare experimental illustration of integrated control, where chemical and biological controls “augment one another”. Our approach and methodology could be applied to demonstrate and validate integrated control in many other systems, addressing a critical need for implementation of biological control in practicing IPM systems.

Conservation of natural enemies in cotton: comparative selectivity of acetamiprid in the management of Bemisia tabaci

The integrated control concept emphasizes the importance of both chemical and biological control for pest suppression in agricultural systems. A two-year field study was conducted to evaluate the selectivity of acetamiprid for the control of Bemisia tabaci (Gennadius) in cotton compared with a proven selective regime based on the insect growth regulators (IGRs) pyriproxyfen and buprofezin. Acetamiprid was highly effective in controlling all stages of B tabaci compared with an untreated control, and generally produced lower pest densities than the IGR regime. Univariate analyses indicated that nine of 17 taxa of arthropod predators were significantly depressed with the use of acetamiprid compared with an untreated control, including common species such as Geocoris punctipes (Say), Orius tristicolor (White), Chrysoperla carnea Stephens sensu lato, Collops vittatus (Say), Hippodamia convergens Guérin-Méneville, and Drapetis nr divergens. Compared with results from independent, concurrent studies using mixtures of broad-spectrum insecticides at the same research site, acetamiprid depressed populations of fewer predator taxa; but, for eight predator taxa significantly affected by both regimes, the average population reduction was roughly equal. In contrast, only four taxa were significantly reduced in the IGR regime compared with the untreated control and three of these were omnivores that function primarily as plant pests. Principal response curves analyses (a time-dependent, multivariate ordination method) confirmed these patterns of population change for the entire predator community. Predator:prey ratios generally increased with the use of both IGRs and acetamiprid compared with an untreated control, but ratios were consistently higher with IGRs. Parasitism by aphelinid parasitoids was unaffected or depressed slightly in all insecticide regimes compared with the control. Because of its high efficacy, acetamiprid may play an important role in later stages of B tabaci control where less emphasis is placed on selectivity. However, our results suggest that acetamiprid would be a poor substitute for the currently used IGRs in the initial stage of control where insecticide selectivity is crucial to a functional integrated control program for B tabaci in cotton.

Power quality improvement using integral-PWM control in an AC/AC voltage converter

Abstract Power electronic systems generate harmonics. Harmonic attenuation is important in the improvement of power quality. For power control, using specified pulse width modulated (PWM) phase control per cycle of the AC supply reduces the harmonic impact of many AC-to-AC electronic controllers. This paper describes a novel power controller that uses an integral cycle-PWM phase controlled converter with one bi-directional semiconductor switch. The converter does not need synchronization with the supply. The controlling PWM signal is modulated to generate maximum fundamental component and minimum harmonic content of the load voltage and current. The circuit topology presented in this paper diminishes the inherited drawback of using the phase or integral cycle control concept used intensively for electric heating applications. The technique offers the advantages of simplicity and reliability of controlling high power and low harmonic levels. Power injected to the load can be precisely controlled resulting in high conversion efficiency.

Robust learning control method in saturating actuators

Anti-reset windup is an important tool in the practical implementation of integral controllers. Integral control can have poor performance due to windup of the integral during transient periods when the actuator is operating at its saturation limit. Anti-reset windup speeds up the departure from the saturation limit by stopping the build-up of the integral during saturation. The most basic form of learning and repetitive control makes use of integral control concepts applied in the repetition domain. Therefore, this paper studies the use of anti-reset windup concepts in learning control. The integral is operating in repetitions, but the system dynamics are in time, making the application nonstandard. Various forms of anti-reset windup are developed for use in learning and repetitive control, and shown to improve performance of the learning process, especially when one does not know enough about the system to obtain well-behaved learning transients. Anti-reset windup is also shown to be helpful in situations where the desired trajectory is not feasible, and in situations where the initial conditions are systematically in error, such as in a robot subject to gravity disturbance.

Acceptance of optimal operation and control methods for greenhouse cultivation

Using information about crop growth would allow to expand present greenhouse control strategies towards a truly economical optimal control strategy. After a short description of the greenhouse-crop system, a survey is given of developments presented in the literature. A full solution would require to consider all relevant key variables, i.e. temperature, CO 2 and humidity, as well as the greenhouse dynamics and the short term variations in external conditions. The factors that hamper the acceptance of such solutions are briefly discussed. An analysis is given on simplified approaches resulting from integrating the crop equations over a day or more. This leads to temperature integral control concepts, which, although sub-optimal, are more easily accepted in practice.

Acceptance of Optimal Operation and Control Methods for Greenhouse Cultivation

Using information about crop growth would allow to expand present greenhouse control strategies towards a truly economical optimal control strategy. After a short description of the greenhouse-crop system, a survey is given of developments presented in the literature. A full solution would require to consider all relevant key variables, i.e. temperature, CO2 and humidity, as well as the greenhouse dynamics and the short term variations in external conditions. The factors that hamper the acceptance of such solutions are briefly discussed. An analysis is given on simplified approaches resulting from integrating the crop equations over a day or more. This leads to temperature integral control concepts, which, although sub-optimal, are more easily accepted in practice