The cost digest : cost summaries of selected environmental control technologies /

Mode of access: Internet.

Evaluation of environmental control technologies for magnetic fields /

August 1978.

Control of infrastructure inspection aircraft vertical dynamics in the presence of thermal disturbances

The low-altitude aircraft inspection of powerlines, or other linear infrastructure networks, is emerging as an important application requiring specialised control technologies. Despite some recent advances in automated control related to this application, control of the underactuated aircraft vertical dynamics has not been completely achieved, especially in the presence of thermal disturbances. Rejection of thermal disturbances represents a key challenge to the control of inspection aircraft due to the underactuated nature of the dynamics and specified speed, altitude, and pitch constraints. This paper proposes a new vertical controller consisting of a backstepping elevator controller with feedforward-feedback throttle controller. The performance of our proposed approach is evaluated against two existing candidate controllers.

Utilizing the assassin bug, Pristhesancus plagipennis (Hemiptera: Reduviidae), as a biological control agent within an integrated pest management programme for Helicoverpa spp. (Lepidoptera: Noctuidae) and Creontiades spp. (Hemiptera: Miridae) in cotton

Helicoverpa spp. and mirids, Creontiades spp., have been difficult to control biologically in cotton due to their unpredictable temporal abundance combined with a cropping environment often made hostile by frequent usage of broad spectrum insecticides. To address this problem, a range of new generation insecticides registered for use in cotton were tested for compatibility with the assassin bug, Pristhesancus plagipennis (Walker), a potential biological control agent for Helicoverpa spp. and Creontiades spp. Indoxacarb, pyriproxifen, buprofezin, spinosad and fipronil were found to be of low to moderate toxicity on P. plagipennis whilst emamectin benzoate, abamectin, diafenthiuron, imidacloprid and omethaote were moderate to highly toxic. Inundative releases of P. plagipennis integrated with insecticides identified as being of low toxicity were then tested and compared with treatments of P. plagipennis and the compatible insecticides used alone, conventionally sprayed usage practice and an untreated control during two field experiments in cotton. The biological control provided by P. plagipennis nymphs when combined with compatible insecticides provided significant (P<0.001) reductions in Helicoverpa and Creontiades spp. on cotton and provided equivalent yields to conventionally sprayed cotton with half of the synthetic insecticide input. Despite this, the utilization of P. plagipennis in cotton as part of an integrated pest management programme remains unlikely due to high inundative release costs relative to other control technologies such as insecticides and transgenic (Bt) cotton varieties.

Multiprotocol Android Application for Smart Control and Monitoring in Buildings

This paper presents a multiprotocol mobile application for building automation which supports and enables the integration of the most representative control technologies such as KNX, LonWorks and X-10. The application includes a real-time monitoring service. Finally, advanced control functionalities based on gestures recognition and predefined scenes have been implemented. This application has been developed and tested in the Energy Efficiency Research Facility located at CeDInt-UPM, where electrical loads, blinds and HVAC and lighting systems can be controlled.

A new latching control technology for improving wave energy conversion

Extracting wave energy from seas has been proven to be very difficult although various technologies have been developed since 1970s. Among the proposed technologies, only few of them have been actually progressed to the advanced stages such as sea trials or pre-commercial sea trial and engineering. One critical question may be how we can design an efficient wave energy converter or how the efficiency of a wave energy converter can be improved using optimal and control technologies, because higher energy conversion efficiency for a wave energy converter is always pursued and it mainly decides the cost of the wave energy production. In this first part of the investigation, some conventional optimal and control technologies for improving wave energy conversion are examined in a form of more physical meanings, rather than the purely complex mathematical expressions, in which it is hoped to clarify some confusions in the development and the terminologies of the technologies and to help to understand the physics behind the optimal and control technologies. As a result of the understanding of the physics and the principles of the optima, a new latching technology is proposed, in which the latching duration is simply calculated from the wave period, rather than based on the future information/prediction, hence the technology could remove one of the technical barriers in implementing this control technology. From the examples given in the context, this new latching control technology can achieve a phase optimum in regular waves, and hence significantly improve wave energy conversion. Further development on this latching control technologies can be found in the second part of the investigation.

Adaptive load shedding and regional protection

The requirement for improved efficiency whilst maintaining system security necessitates the development of improved system analysis approaches and the development of advanced emergency control technologies. Load shedding is a type of emergency control that is designed to ensure system stability by curtailing system load to match generation supply. This paper presents a new adaptive load shedding scheme that provides emergency protection against excess frequency decline, whilst minimizing the risk of line overloading. The proposed load shedding scheme uses the local frequency rate information to adapt the load shedding behaviour to suit the size and location of the experienced disturbance. The proposed scheme is tested in simulation on a 3-region, 10-generator sample system and shows good performance.

Adoption of low-cost rail level crossing warning devices : an Australian case study

The objective of this chapter is to provide rail practitioners with a practical approach for determining safety requirements of low-cost level crossing warning devices (LCLCWDs) on an Australian railway by way of a case study. LCLCWDs, in theory, allow railway operators to improve the safety of passively controlled crossing by upgrading a larger number of level crossings with the same budget that would otherwise be used to upgrade these using the conventional active level crossing control technologies, e.g. track circuit initiated flashing light systems. The chapter discusses the experience and obstacles of adopting LCLCWDs in Australia, and demonstrates how the risk-based approach may be used to make the case for LCLCWDs.

Public Space and the Marginalisation of Children and Young People

Throughout much of the world, urban and rural public spaces may be said to be under attack by property developers, commercial interests and also attempts by civic authorities to regulate, restrict, reframe and rebrand these spaces. A consequence of the increasingly security driven, privatised, commercial and surveilled nature of public space is the exclusion and displacement of those considered ‘flawed’ and unwelcome in the ‘spectacular’ consumption spaces of many major urban centres. In the name of urban regeneration, processes of securitisation, ‘gentrification’ and creative cities initiatives can act to refashion public space as sites of selective inclusion and exclusion. The use of surveillance and other control technologies as deployed in and around the UK ‘Riots’ of 2011 may help to promote and encourage a passing sense of personal safety and confidence in using public space. Through systems of social sorting, the same surveillance assemblages can also further the physical, emotional and psychological exclusion of certain groups and individuals, deemed to be both ‘out of time and out of place’ in major zones of urban, conspicuous, consumption. In this harsh environment of monitoring and control procedures, children and young people’s use of public spaces and places in parks, neighbourhoods, shopping malls and streets is often viewed as a threat to social order, requiring various forms of punitive and/or remedial action. Much of this civic action actively excludes some children and young people from participation and as a consequence, their trust in local processes and communities is eroded. This paper discusses worldwide developments in the surveillance, governance and control of the public space environments used by children and young people in particular and the capacity for their displacement and marginality, diminishing their sense of belonging, wellbeing and rights to public space as an expression of their social, political and civil citizenship(s).

Association rule mining activity : A general formalism

Mining association rules from a large collection of databases is based on two main tasks. One is generation of large itemsets; and the other is finding associations between the discovered large itemsets. Existing formalism for association rules are based on a single transaction database which is not sufficient to describe the association rules based on multiple database environment. In this paper, we give a general characterization of association rules and also give a framework for knowledge-based mining of multiple databases for association rules.

A Scalable Architecture for VoIP Conferencing

Real-Time services are traditionally supported on circuit switched network. However, there is a need to port these services on packet switched network. Architecture for audio conferencing application over the Internet in the light of ITU-T H.323 recommendations is considered. In a conference, considering packets only from a set of selected clients can reduce speech quality degradation because mixing packets from all clients can lead to lack of speech clarity. A distributed algorithm and architecture for selecting clients for mixing is suggested here based on a new quantifier of the voice activity called “Loudness Number” (LN). The proposed system distributes the computation load and reduces the load on client terminals. The highlights of this architecture are scalability, bandwidth saving and speech quality enhancement. Client selection for playing out tries to mimic a physical conference where the most vocal participants attract more attention. The contributions of the paper are expected to aid H.323 recommendations implementations for Multipoint Processors (MP). A working prototype based on the proposed architecture is already functional.

Violências na contemporaneidade: etnografia de redes sociotécnicas na Cidade de Chapecó (SC)

O objetivo deste estudo foi investigar os dispositivos que permitem instituir a "violência" na contemporaneidade como uma questão constituinte e mobilizadora de coletivos (para o seu estudo, o seu combate, a sua divulgação, proteção frente à mesma, atendimento às suas vítimas e atendimento ou punição a seus agentes), na cidade de Chapecó. Para esta finalidade, foram utilizados princípios, regras e propriedades metodológicas da Teoria do Ator-Rede, concebida por Bruno Latour, John Law e Michel Callon, que guiaram a etnografia realizada; a Teoria da Sociedade Global de Riscos, proposta por Ulrich Beck, que permitiu compreender configurações contemporâneas; e noções de Michel Foucault, Gilles Deleuze e Felix Guattari que possibilitaram focar processos vinculados às gestões das violências, como a mídia e as tecnologias de vigilância e controle. A violência foi constituída como um artefato da pesquisa e conduziu ao conhecimento dos vários sentidos tomados no espaço de sua circulação. No lugar de tomar uma definição a priori para relacioná-la ao empírico, o estudo optou por uma forma de compreendê-la, com base nos referenciais escolhidos: não como causa, mas como efeito, configurando redes sociotécnicas que articulam diferentes elementos; não um reservatório que forneceria automaticamente uma explicação, mas o resultado final de um processo, que envolve mediadores em sua fabricação. A pesquisa foi realizada em Chapecó, cidade de porte médio, localizada no Oeste de Santa Catarina, diferenciando-se dos grandes centros urbanos, nos quais as violências vêm sendo predominantemente estudadas. O trabalho de campo englobou diferentes momentos (2004, 2005 e 2006) e trilhou diferentes caminhos para a coleta de indicadores. O primeiro investigando histórias da cidade e região com ênfase nos estudos referentes a situações que ficaram marcadas como violentas. O segundo observando a cidade como um todo, tendo em vista eventos, atores e coletivos que se constituíram vinculados à categoria violência. O terceiro focando e descrevendo cinco eventos contemporâneos específicos vinculados às práticas violentas, à gestão das violências, à produção de segurança e à mídia escrita de Chapecó. A amplitude e a diversidade, abrangidas pela etnografia, evidenciaram que as configurações das práticas violentas se constituem conectadas aos processos de inscrição dessas práticas, aos processos de tradução das categorias que as definem e as estratégias de gestão das violências, que implicam em tecnologias de vigilância e controle. As múltiplas entradas para abordar o tema fizeram ressoar as misturas que envolvem a sua discussão, a infinitude de variáveis em jogo e a multiplicidade que compõe as violências. Os eventos estudados tornaram perceptível a trama de redes que constituem a violência no município, redes que disputam e fazem alianças, conectando uma diversidade de actantes que as fabricam cotidianamente. Dessa forma, a violência não deve ser delegada a alguns atores apenas, mas pode ser compreendida como efeito de redes sociotécnicas extensas que articulam diferentes actantes, a partir dos vínculos que os ligam, da tradução dos interesses que os unem e dos traços que inscrevem os seus deslocamentos.

地质导向钻井关键技术及方法

On the basis of analyzing the principle and realization of geo-steering drilling system, the key technologies and methods in it are systematically studied in this paper. In order to recognize lithology, distinguish stratum and track reservoirs, the techniques of MWD and data process about natural gamma, resistivity, inductive density and porosity are researched. The methods for pre-processing and standardizing MWD data and for converting geological data in directional and horizontal drilling are discussed, consequently the methods of data conversion between MD and TVD and those of formation description and adjacent well contrast are proposed. Researching the method of identifying sub-layer yields the techniques of single well explanation, multi-well evaluation and oil reservoir description. Using the extremum and variance clustering analysis realizes logging phase analysis and stratum subdivision and explanation, which provides a theoretical method and lays a technical basis for tracing oil reservoirs and achieving geo-steering drilling. Researching the technique for exploring the reservoir top with a holdup section provides a planning method of wellpath control scheme to trace oil and gas reservoir dynamically, which solves the problem of how to control well trajectory on condition that the layer’s TVD is uncertain. The control scheme and planning method of well path for meeting the demands of target hitting, soft landing and continuous steering respectively provide the technological guarantee to land safely and drill successfully for horizontal, extended-reach and multi-target wells. The integrative design and control technologies are researched based on geology, reservoir and drilling considering reservoir disclosing ratio as a primary index, and the methods for planning and control optimum wellpath under multi-target restriction, thus which lets the target wellpath lie the favorite position in oil reservoir during the process of geo-steering drilling. The BHA (bottomhole assembly) mechanical model is discussed using the finite element method, and the BHA design methods are given on the basis of mechanical analyses according to the shape of well trajectory and the characteristics of BHA’s structure and deformation. The methods for predicting the deflection rate of bent housing motors and designing their assemblies are proposed based on the principle of minimum potential energy, which can clearly show the relation between the BHA’s structure parameters and deflection rate, especially the key factors’ effect to the deflection rate. Moreover, the interaction model between bit and formation is discussed through the process of equivalent formation and equivalent bit considering the formation anisotropy and bit anisotropy on the basis of analyzing the influence factors of well trajectory. Accordingly, the inherence relationship among well trajectory, formation, bit and drilling direction is revealed, which lays the theory basis and technique for predicting and controlling well trajectory.