A coordinated voltage control approach for coordination of OLTC, voltage regulator and DG to regulate voltage in a distribution feeder

Integration of small-scale electricity generators, known as Distributed Generation (DG), into the distribution networks has become increasingly popular at the present. This tendency together with the falling price of synchronous-type generator has potential to give the DG a better chance in participating in the voltage regulation process together with other devices already available in the system. The voltage control issue turns out to be a very challenging problem for the distribution engineers since existing control coordination schemes would need to be reconsidered to take into account the DG operation. In this paper, we propose a control coordination technique, which is able to utilize the ability of the DG as a voltage regulator, and at the same time minimizes interaction with other active devices, such as On-load Tap Changing Transformer (OLTC) and voltage regulator. The technique has been developed based on the concept of control zone, Line Drop Compensation (LDC), as well as the choice of controller's parameters. Simulations carried out on an Australian system show that the technique is suitable and flexible for any system with multiple regulating devices including DG.

A coordinated voltage control approach for coordination of OLTC, voltage regulator, and DG to regulate voltage in a distribution feeder

Integration of small-scale electricity generators, known as distributed generation (DG), into the distribution networks has become increasingly popular at the present. This tendency together with the falling price of the synchronous-type generator has potential to give DG a better chance at participating in the voltage regulation process together with other devices already available in the system. The voltage control issue turns out to be a very challenging problem for the distribution engineers since existing control coordination schemes would need to be reconsidered to take into account the DG operation. In this paper, we propose a control coordination technique, which is able to utilize the ability of DG as a voltage regulator and, at the same time, minimize interaction with other active devices, such as an on-load tap changing transformer and a voltage regulator. The technique has been developed based on the concept of control zone, line drop compensation, dead band, as well as the choice of controllers' parameters. Simulations carried out on an Australian system show that the technique is suitable and flexible for any system with multiple regulating devices including DG.

A model to store coordination mappings

Exploratory tasks supported by visualization are usually improved by Coordinated and Multiple Views (CMV) of the data under study. Several coordination techniques have been proposed in the literature, resulting in a diversity of tools to generate mappings among the multiple views. These mappings can be highly dynamic, and their history reveals the settings employed in the multiple exploratory tasks conducted in a discovery process. Several solutions have been proposed to help users to recover the steps performed in exploratory tasks, but little support is found for registering the multiple coordination mappings employed. This paper provides a contribution in this direction, proposing a model for storing and recovering such mappings. We believe such a facility is an important feature of CMV systems, so that users can recover and rerun the coordinations performed when exploring their data. We present details of the proposed model and show some potential applications. © 2012 IEEE.

Múltiplas visões coordenadas: uma técnica de coordenação com o apoio de ontologias

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Quantifying variability within technique and performance in elite fast bowlers : is technical variability dysfunctional or functional?

In fast bowling, cricketers are expected to produce a range of delivery lines and lengths while maximising ball speed. From a coaching perspective, technique consistency has been typically associated with superior performance in these areas. However, although bowlers are required to bowl consistently, at the elite level they must also be able to vary line, length and speed to adapt to opposition batters’ strengths and weaknesses. The relationship between technique and performance variability (and consistency) has not been investigated in previous fast bowling research. Consequently, the aim of this study was to quantify both technique (bowling action and coordination) and performance variability in elite fast bowlers from Australian Junior and National Pace Squads. Technique variability was analysed to investigate whether it could be classified as functional or dysfunctional in relation to speed and accuracy.

A novel tuning method for advanced line drop compensator and its application to response coordination of distributed generation with voltage regulating devices

Nowadays, integration of small-scale electricity generators, known as Distributed Generation (DG), into distribution networks has become increasingly popular. This tendency together with the falling price of DG units has a great potential in giving the DG a better chance to participate in voltage regulation process, in parallel with other regulating devices already available in the distribution systems. The voltage control issue turns out to be a very challenging problem for distribution engineers, since existing control coordination schemes need to be reconsidered to take into account the DG operation. In this paper, a control coordination approach is proposed, which is able to utilize the ability of the DG as a voltage regulator, and at the same time minimize the interaction of DG with another DG or other active devices, such as On-load Tap Changing Transformer (OLTC). The proposed technique has been developed based on the concepts of protection principles (magnitude grading and time grading) for response coordination of DG and other regulating devices and uses Advanced Line Drop Compensators (ALDCs) for implementation. A distribution feeder with tap changing transformer and DG units has been extracted from a practical system to test the proposed control technique. The results show that the proposed method provides an effective solution for coordination of DG with another DG or voltage regulating devices and the integration of protection principles has considerably reduced the control interaction to achieve the desired voltage correction.

Ternary copper(II) complexes of thiosemicarbazones and heterocyclic bases showing N3OS coordination as models for the type-2 centers of copper monooxygenases

Six ternary copper(II) complexes of general formulation [CuLB] (1-6), where L is dianionic ONS-donor thiosemicarbazones derived from the condensation of salicylaldehyde with thiosemicarbazides and B is NN-donor heterocyclic bases like 2,2'-bipyridine, 1,10-phenanthroline and 2,9-dimethyl-1,10-phenanthroline, are prepared from a reaction of copper(II) acetate hydrate with the heterocyclic base (B) and the thiosemicarbazone (H2L) in MeOH, and structurally characterized by X-ray diffraction technique. Crystal structures of the complexes display a distorted square-pyramidal (4 + 1) coordination geometry having the ONS-donor thiosemicarbazone bonded at the basal plane. The chelating heterocyclic bases exhibit axial-equatorial mode of bonding. The complexes are one-electron paramagnetic and they show axial X-band EPR spectra in DMF-toluene glass at 77 K giving g(parallel to)(A(parallel to)) and g(perpendicular to) values of similar to2.2 (175 x 10(-4) cm(-1)) and similar to2.0 indicating a {d(x2-y2)}(1) ground state. The complexes show a d-d band near 570 nm and a charge transfer band near 400 nm in DMF. The complexes are redox active and exhibit a quasireversible Cu(II)-Cu(I) couple in DMF-0.1 M tetrabutylammonium perchlorate near 0.1 V vs. SCE. They are catalytically active in the oxidation of ascorbic acid in presence of dioxygen. The complexes with a CuN3OS coordination model the ascorbate oxidation property of dopamine beta-hydroxylase and peptidylglycine a-hydroxylating monooxygeanase. (C) 2003 Elsevier Science B.V. All rights reserved.

A two-dimensional molybdenum (V) phosphate with covalently bonded transition metal coordination complexes: hydrothermal synthesis and structure characterization of Na-2[{Mn(phen)(2)(H2O)}{Mn(phen)(2)}(3){Mn (Mo12O24)-O-V (HPO4)(6)(PO4)(2)(OH)(6)}] center dot 4H(2)O (phen=1,10-phenanthroline)

An organic-inorganic hybrid molybdenum phosphate, Na-2[{Mn(phen)(2)(H2O)} {Mn(phen)(2)}(3){(MnMo12O24)-O-v (HPO4)(6)(PO4)(2) (OH)(6)}] . 4H(2)O (phen=1,10-phenanthroline), involving molybdenum present in V oxidation state and covalently bonded transition metal coordination complexes, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a=16.581(l)Angstrom, b=18.354(1)Angstrom, c=24.485(2)Angstrom, alpha=80.589(l)degrees, beta=71.279(1)degrees, gamma=67.084(1)degrees, V=6493.8(8)Angstrom(3), Z=2, lambda(MoKalpha)=0.71073Angstrom (R(F)=0.0686 for 29,053 reflections). Data were collected on a Bruker Smart Apex CCD diffractometer at 293 K in the range of 1.76 < theta < 28.06degrees using omega-2theta scans technique. The structure of the title compound may be considered to be based on {Mo6O12(HPO4)(3)(PO4)(OH)(3)} units bonded together with {Mn(phen)(2)} subunits into a two-dimensional network. Two types of tunnels are observed in the solid of the title compound.

Hydrothermal synthesis and crystal structure of [{Cu(2,2 '-bpy)(2)}(2)Mo8O26]: a beta-octamolybdate cluster covalently bonded to two {Cu(2,2 '-bpy)(2)}(2+) coordination complexes via bridging oxo groups

An organic-inorganic hybrid solid, (Cu(2,2'-bpy)(2))(2)Mo8O26, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Dark green crystals crystallize in the orthorhombic system, space group Pna21, a = 24.164(5), b = 18.281(4), c = 11.877(2) Angstrom, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, V= 5247(2) Angstrom (3), Z = 4, lambda (MoK alpha) = 0.71073 Angstrom (R(F) = 0.0331 for 5353 reflections). Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.69 degrees < theta < 25.04 degrees using the omega -scan technique. The structure was solved by the direct method and refined by full-matrix least squares on F-2 using SHELXL-93. The structure of this compound consists of discrete (Cu(2,2'-bpy)(2))(2)Mo8O26 clusters, constructed from beta -octamolybdate subunits ((Mo8O26)(4-)) covalently bonded to two (Cu(2,2'-bpy)(2))(2+) coordination complexes via bridging oxo groups that connect two adjacent molybdenum sites. (C) 2001 Academic Press.

Studies on two coordination polymers [M(mu(4)-pz25dc)](n) (M = Cd or Zn, pz25dc=pyrazine-2,5-dicarboxylato) with three-dimensional pillared-layer three-nodal framework: Synthesis, structural characterization, strong optical non-linearities and optical limiting properties

Two isomorphous new candidates [M(mu(4)-pz25dc)](n) (M = Cd, 1; Zn, 2; pz25dc = pyrazine-2,5-dicarboxylato)for nonlinear optical (NLO) materials have been synthesized hydrothermally and characterized crystallographically as pillared-layer three-nodal frameworks with one four-connected metal nodes and two crystallographically different four-connected ligand nodes. Their optical non-linearities are measured by the Z-Scan technique with an 8 ns pulsed laser at 532 nm. These two coordination polymers both exhibit strong NLO absorptive abilities [alpha(2) = (63 +/- 6) x 10 (12) mW (1) 1, ( 46 +/- 6) x 10 (11) mW (1) 2] and effective self-focusing performance [n(2) = (67 +/- 5) x 10 (18) 1, (13 +/- 3) x 10 (18) m(2) W (1) 2] in 1.02 x 10 (4) 1 and 1.05 x 10 (4) mol dm (3) 2 DMF solution separately. The values of the limiting threshold are also measured from the optical limiting experimental data. The heavy atom effect plays important role in the enhancement of optical non-linearities and optical limiting properties. (C) 2009 Elsevier B. V. All rights reserved.

Liquid alumina: detailed atomic coordination determined from neutron diffraction data using empirical potential structure refinement

Greaves, George; Jenkins, T.E.; Landron, C.; Hennet, L., (2001) 'Liquid alumina: detailed atomic coordination determined from neutron diffraction data using empirical potential structure refinement', Physical Review Letters 86 pp.4839-4842 RAE2008

Spontaneous transitions in the coordination of a whole body task

This paper describes an example of spontaneous transitions between qualitatively different coordination patterns during a cyclic lifting and lowering task. Eleven participants performed 12 trials of repetitive lifting and lowering in a ramp protocol in which the height of the lower shelf was raised or lowered I cm per cycle between 10 and 50 cm. Two distinct patterns of coordination were evident: a squat technique in which moderate range of hip, knee and ankle movement was utilised and ankle plantar-flexion occurred simultaneously with knee and hip extension; and a stoop technique in which the range of knee movement was reduced and knee and hip extension was accompanied by simultaneous ankle dorsi-flexion. Abrupt transitions from stoop to squat techniques were observed during descending trials, and from squat to stoop during ascending trials. Indications of hysteresis was observed in that transitions were more frequently observed during descending trials, and the average shelf height at the transition was 5 cm higher during ascending trials. The transitions may be a consequence of a trade-off between the biomechanical advantages of each technique and the influence of the lift height on this trade-off. (C) 2001 Elsevier Science B.V. All rights reserved.

Fast atom bombardment mass spectrometry of the coordination complexes of the ligand 5, 5, 7, 12, 12, 14- hexamenthyl-1, 4, 8, 11-tetraazacycloteradecane

A number of metal complexes containing the ligand 5,5,7,12,12,14-hexamethyl-l,4,8,11-tetra-azatetradecane were synthesized and analyzed using electron impact (EI) and fast atom bombardment (FAB). The FAB mass spectra were obtained in positive and negative ion mode. FAB in the positive ion mode proved to be the most successful technique for the identification of these compounds. In the majority of cases the spectra obtained using positive ion FAB were structurally informative, although not all showed molecular (M+) or quasimolecular ([M+H]+) ions. The fragmentations observed were characteristic of the ligands, and were interpreted based on the chemistry of these compounds.

Fast atom bombardment mass spectrometry studies of ruthenium (II) polypyridy coordination complexes and of group V Triptycenes and related complexes

In order to investigate the use of Fast Atom Bombardment Mass Spectrometry (FAB-MS) as a tool for structural characterization, two groups of complexes are analyzed. The first group is a set of ruthenium(II) coordination complexes containing bidentate polypyridyl ligands. The positive and negative ion FAB-MS spectra are found to be sufficient to allow for an almost complete characterization of the central metal atom, the ligands and the counter anions contained in the intact complex. An unusual observation of mUltiply charged ions in the positive ion FAB-MS spectra (i.e. [RUL 3 ]2+) is explained to be as a result of the oxidative quenching of the excited state of the doubly charged ion by the matrix, 3-nitrobenzyl alcohol. An analysis of a mixture shows that the technique is a good one for identifying components therein. A group of triptycene and related complexes containing Group V elements is also analyzed by FAB-MS and the results. in terms of relative abundances of fragment ions, are found to be consistent with known metal-carbon bond strengths.

Le transfert informel des connaissances tacites chez les gestionnaires municipaux en situation de coordination

Ce rapport de recherche porte sur une étude s’intéressant au transfert des connaissances tacites chez les gestionnaires, c’est-à-dire le partage de ces connaissances et leur utilisation informelle, durant une situation de coordination dans un service municipal. La thèse est articulée autour des questions suivantes : Quelles sont les situations de coordination vécues par les gestionnaires municipaux? Quelles sont les sources de connaissances tacites partagées et utilisées? Quelles sont les relations de connaissances mobilisées de façon informelle lors du transfert des connaissances tacites? Quels sont les facteurs encourageant ou inhibant le transfert informel des connaissances tacites? À partir d’un modèle basé sur une approche situationnelle (Taylor, 1989 et 1991), nous avons revu la documentation touchant nos questions de recherche. Nous avons défini notamment la récursivité des connaissances et le réseau de connaissances, de même que présenté le modèle de la conversion des connaissances (Nonaka, 1994) et celui de l’actualisation de soi (St-Arnaud, 1996). Nous avons questionné 22 répondants à l’aide d’instruments de mesure qui combinent les techniques de l’incident critique, de l’entrevue cognitive et réflexive, le questionnement sur les réseaux organisationnels et l’observation participante. Tels des filets, ces instruments ont permis de traquer et d’obtenir des données d’une grande richesse sur les connaissances tacites et les comportements informels durant le transfert de connaissances en situation de coordination. Ces données ont été analysées selon une approche méthodologique essentiellement qualitative combinant l’analyse de contenu, la schématisation heuristique et l’analyse des réseaux sociaux. Nos résultats montrent que la complexité d’une situation de coordination conditionne le choix des mécanismes de coordination. De plus, les sources de connaissances sont, du point de vue individuel, le gestionnaire et ses artefacts, de même que son réseau personnel avec ses propres artefacts. Du point de vue collectif, ces sources sont réifiées dans le réseau de connaissances. Les connaissances clés d’une situation de coordination sont celles sur le réseau organisationnel, le contexte, les expériences en gestion et en situation complexe de coordination, la capacité de communiquer, de négocier, d’innover et celle d’attirer l’attention. Individuellement, les gestionnaires privilégient l’actualisation de soi, l’autoformation et la formation contextualisée et, collectivement, la coprésence dans l’action, le réseautage et l’accompagnement. Cette étude fournit un modèle valide du transfert contextualisé des connaissances qui est un cas de coordination complexe d’activités en gestion des connaissances. Ce transfert est concomitant à d’autres situations de coordination. La nature tacite des connaissances prévaut, de même que le mode informel, les médias personnels et les mécanismes d’ajustement mutuel. Les connaissances tacites sont principalement transférées au début des processus de gestion de projet et continuellement durant la rétroaction et le suivi des résultats. Quant aux connaissances explicites, les gestionnaires les utilisent principalement comme un symbole à la fin des processus de gestion de projet. Parmi les personnes et les groupes de personnes d’une situation de transfert contextualisé des connaissances, 10 % jouent des rôles clés, soit ceux d’experts et d’intermédiaires de personnes et d’artefacts. Les personnes en périphérie possèdent un potentiel de structuration, c’est-à-dire de connexité, pour assurer la continuité du réseau de connaissances organisationnel. Notre étude a élargi le modèle général de la complexité d’une situation (Bystrom, 1999; Choo, 2006; Taylor, 1986 et 1991), la théorie de la coordination (Malone et Crowston, 1994), le modèle de la conversion des connaissances (Nonaka, 1994), celui de l’actualisation de soi (St-Arnaud, 1996) et la théorie des réseaux de connaissances (Monge et Contractor, 2003). Notre modèle réaffirme la concomitance de ces modèles généraux selon une approche constructiviste (Giddens, 1987) où la dualité du structurel et la compétence des acteurs sont confirmées et enrichies.