Multi-phase state estimation featuring industrial-grade distribution network models

This paper proposes a novel implementation of a multi-phase distribution network state estimator which employs industrial-grade modeling of power components and measurements. Unlike the classical voltage-based and current-based state estimators, this paper presents the implementation details of a constrained weighted least squares state calculation method that includes standard three-phase state estimation capabilities in addition to practical modeling requirements from the industry; these requirements comprise multi-phase line configurations, unsymmetrical and incomplete transformer connections, power measurements on 4-connected loads, cumulative-type power measurements, line-to-line voltage magnitude measurements, and reversible line drop compensators. The enhanced modeling equips the estimator with capabilities that make it superior to a recently presented state-of-the-art distribution network load estimator that is currently used in real-life distribution management systems; comparative performance results demonstrate the advantage of the proposed estimator under practical measurement schemes

Parent Communication and Earthquake Safety

The action research study investigated increasing communication on earthquake safety in order to alleviate parental concern. The investigation took place at a local private Montessori school. The participants were parents from the school. The data was collected through pre and post surveys, observations, and journaling. The results showed that increasing communication between the school and the parent community on this subject matter did alleviate parental concern. The parents felt more reassured knowing the details on earthquake safety plan. However, the challenge is keeping the new parents that come to the school informed about the school’s earthquake safety plan. Overall, keeping effective communication on this subject with the parent community is the key

Real Time Distribution System State Estimation Based On Interior Point Method

This approach for a three-phase Distribution System State Estimator (DSSE) considers all the analog measurements including voltage and current measurements, active and reactivepower measurements, as well as historical load-information.The estimation of load information is based on an interiorpoint optimization. It reduces the estimation problem to loadgroups which are located in so called measurement areas. Bygrouping the loads with the same weighting factors, the numberof state variables for the optimization is minimized. The powermismatches at the boundary between neighboring areas areeliminated by equality constraints. This significantly reduces sizeof the estimation problem. The proposal is designed for radialas well as for networks with some meshes

Internal and External Obstacles to the Development of SMEs in Bosnia and Herzegovina

This article describes the small and medium enterprise (SME) sectors in Bosnia and Herzegovina (BiH) and other Western Balkan countries, and compares their development. The authors identify the levels of development achieved, remedial measures and activities for stimulating this sector. There is special emphasis on external and internal obstacles to small and medium-sized manufacturing enterprises in BiH. The authors conclude that in respect to SMEs BiH lags behind other countries in the region, where this sector has achieved dynamic development and a majority share in the employment market, exports and GDP. That said, there remains a need across the whole region to resolve obstacles in the domestic market, alongside initiating intensive activities aimed at introducing the SMEs to the Single European Market. For BiH, primary research has been carried out to determine the external and internal obstacles to SMEs in the country’s manufacturing sector. The key obstacles are identified, their intensity and grade determined, and they are classified into three groups. Factor analysis was used in determining six factors explaining external obstacles and two factors for internal obstacles. It has also been confirmed that other companies apart from manufacturing SMEs face broadly similar external obstacles, and that these obstacles are more in evidence when compared to the situation in other Western Balkan countries. Recommendations are offered to the Government of BiH and SME managements for removing the obstacles which have been identified.SMEs, manufacturing, obstacles, factor analysis, Western Balkans, Bosnia and Herzegovina (BiH)

A Component-Based Power System Model-Driven Architecture

This letter describes an approach of applying the model-driven development in power systems. A component-based model-driven architecture,that gives full flexibility of the automation in source code generation,is introduced. A design pattern to code generation is described

Neural correlates of dynamic emotion perception in schizophrenia and the influence of prior expectations.

Impaired emotion perception is a well-established and stable deficit in schizophrenia; however, there is limited knowledge about the underlying aberrant cognitive and brain processes that result in emotion perception deficits. Recent influential work has shown that perceptual deficits in schizophrenia may result from aberrant precision in prior expectations, associated with disrupted activity in frontal regions. In the present study, we investigated the perception of dynamic, multisensory emotion, the influence of prior expectations and the underlying aberrant brain processes in schizophrenia. During a functional Magnetic Resonance Imaging scan, participants completed the Dynamic Emotion Perception task, which induces prior expectations with emotion instruction cues. We delineated neural responses and functional connectivity in whole-brain large-scale networks underlying emotion perception. Compared to healthy individuals, schizophrenia patients had lower accuracy specifically for emotions that were congruent with prior expectations. At the neural level, schizophrenia patients had less engagement of right inferior frontal and parietal regions, as well as right amygdala dysconnectivity during discrimination of emotions congruent with prior expectations. The results indicate that individuals with schizophrenia may have aberrant prior expectations about emotional expressions, associated with under-activity in inferior frontoparietal regions and right amygdala dysconnectivity, which results in impaired perception of emotion

Structure, function and dynamic of Na(+), H(+) antiporters : an infrared spectroscopy study

Die Funktion von Membranproteinen ist von entscheidender Bedeutung für eine Vielzahl zellulärer Prozesse. Um diese verstehen zu können, ist das Verständnis der Beziehungen zwischen der Struktur, der Dynamik und der Wechselwirkung mit der Umgebung der Membranproteine notwendig. Spektroskopische Methoden, wie beispielsweise FTIR- und CD-Spektroskopie sind in der Lage, diese Informationen zu geben. In der vorliegenden Dissertation haben sie bedeutende Beiträge zum Verständnis der durch die Aktivierung induzierten Konformationsänderungen der Na+/H+ Antiporter geleistet. Die hohe Empfindlichkeit einer selbstkonstruierten FTIR-ATR-Perfusionszelle ermöglichte es, über eine Proteinprobe verschiedene Wirkstoffmoleküle perfundieren zu lassen und die dadurch verursachten strukturellen Änderungen spektroskopisch zu charakterisieren. Die Konformationsänderungen, die den Aktivierungsprozess begleiten, wurden bei zwei verschiedenen Na+/H+ Antiportern, NhaA und MjNhaP1, untersucht. Sie werden bei unterschiedlichen pH-Bereichen aktiviert bzw. deaktiviert. Der Na+/H+ Antiporter NhaA aus E. coli hat seine maximale Transportaktivität bei pH 8,5 und ist bei pH 8 inaktiv ist, zeigten, dass ähnlich wie NhaA das Protein im aktiven Zustand bei pH 6 hauptsächlich aus alpha-Helices aufgebaut ist. Es bestand die Möglichkeit, zwei verschiedene Probenpräparationen (Protein in Detergenz bzw. in 2D-Kristallen) zu untersuchen und miteinander zu vergleichen. Die Erhöhung des pH-Werts bei der in Detergenz solubilisierten Probe führte zu einer Abnahme der alpha-helikalen und einer Zunahme der ungeordneten Strukturen. Das äußerte sich auch in den Untersuchungen zur thermischen Stabilität und im (1)H/(2)H Austauschexperiment. Die thermische Stabilität der alpha-Helices nahm mit der Inaktivierung dramatisch ab. Diese Ergebnisse zeigten auch, dass bei der Aktivierung von MjNhaP1 die beta-Faltblattstruktur nicht involviert ist, aber diese von fundamentaler Bedeutung für die Gesamtstabilität des Proteins und wahrscheinlich für den Hauptkontakt zwischen den Monomeren verantwortlich ist. Im Gegensatz zu NhaA ist die Monomer Monomer Wechselwirkung nicht für die Aktivität von MjNhaP1 notwendig. Aufgrund des höheren Anteils von ungeordneter Struktur im inaktiven Zustand der in Detergenz solubilisierten Probe beobachtet man in diesem Zustand einen höheren (1)H/(2)H Austausch. Der Vergleich mit den Ergebnissen des (1)H/(2)H Austausches von 2D-Kristallen ermöglichte die Lokalisation der ungeordneten Struktur an der Außenseite des Proteinmoleküls im inaktiven Zustand. Die pH-induzierten Differenzspektren zeigten, dass die Aktivierung zu einer Helikalisierung des Proteins und einer Protonierungsänderung der Aminosäureseitenketten von Asparaginsäure und/oder Glutaminsäure unabhängig von der Probenpräparation führt. Der Vergleich von NhaA und MjNhaP1 zeigt, dass die Aktivierung in beiden Fällen mit einer Konformationsänderung und Änderung der Protonierung oder der Umgebung von einer oder mehreren Seitenketten von Asparaginsäure oder Glutaminsäure verbunden ist. Dabei sind die Strukturänderungen der beiden Proteine während der Aktivierung ähnlich, bei Inaktivierung jedoch deutlich unterscheidbar. Die pH-induzierten Strukturänderungen wurden bei NhaA und MjNhaP1 durch die Mutanten G338S und R347A, die keine pH-Abhängigkeit der Aktivität zeigen, bestätigt.The function of membrane proteins is crucial for many cellular processes. Understanding the function of a protein requires information about its structure, dynamics and interaction with the environment. Spectroscopic techniques like FTIR- and CD-spectroscopy are widely used to get such information. In the present dissertation these methods provide detailed insights about conformational changes of Na+/H+ antiporters. The use of a novel FTIR-ATR-perfusion-cell to record reaction-induced FTIR-difference spectra enabled us to detect even small changes in secondary structure and dynamics of the protein caused by changes of pH and binding of effector molecules. The conformational changes accompanying the activation of the protein were studied for two different Na+/H+ antiporters, i.e., NhaA and MjNhaP1. These two proteins are active in Na+ and H+ transport in different pH ranges. Na+/H+ antiporter NhaA from E. coli has the highest transport activity at pH 8.5 and is completely inactive below pH 6.5. The structure of NhaA is known for the inactive state at pH 4, however, the conformational changes upon activation and the structure of active state are not yet known. FTIR- and CD-spectra analysis revealed that protein secondary structure is composed mainly of alpha-helical structure, but also of some beta-sheet, loops and unordered structures. The FTIR-spectra of inactive and active state showed two spectral components, which indicate the presence of alpha-helices with different properties. The temperature-induced structural changes and reorganisation of the protein during the unfolding process demonstrate that activation of the protein causes a change in the properties of alpha-helices. Thermal stability of this structure decreases with activation. The structure of beta-sheet, which is responsible for the main contact between monomers, shows different thermal behaviour for the inactive and the active state. While the temperature profiles for alpha-helices and β-sheet structure are the same in the active state, they differ in the inactive state. Hence we could conclude that activity of NhaA is associated with the existence of NhaA as a dimer. Protein dynamics and flexibility in the inactive and the active state were analyzed by probing water and H+ accessibility by 1H/2H exchange experiments. In the hydrophilic region of the protein, the amino acid side chains exchange faster in the active state than in the inactive state as a result of the conformational change concomitant with activation. In the transmembrane region, activation also leads to conformational changes resulting in an open conformation which is more accessible for the solution. The recording of reaction induced difference spectra yielded unique spectroscopic signatures for the “inactive” and “active” states. The difference spectra of pH-titration showed that the pH value has a dramatic effect on the secondary structure as well as on the protonation state of the amino acid side chains. The pH- and Na+-induced activation of the protein leads to structural rearrangement of transmembrane alpha-helices in terms of length, order and/or orientation accompanied by changes in protonation state of glutamic- and/or aspartic acid side chains. pD induced secondary structure changes gave additional information about changes in the environment of tyrosine side chain with activation. Comparison of difference spectra induced by binding of sodium and an inhibitor of transport indicated different binding sites. MjNhaP1 a Na+/H+ antiporter from M. Jannaschii, in contrast to NhaA, is active at pH 6 and inactive at pH 8. Similar to NhaA, the analysis of FTIR- and CD-spectra showed that the secondary structure of MjNhaP1 in the active state is mainly formed by alpha-helices. In this case it was possible to investigate and compare the results of two different sample preparations (detergent and 2D crystals). Increasing the pH-value of detergent-solubilised protein caused a decrease in alpha-helical content and increase in unordered structure content in the secondary structure. The study of thermal stability and water accessibility supported these results. Thermal profiles indicated a dramatic decrease in stability of alpha-helical structure with inactivation of the protein. These results showed also that beta-sheet part of the secondary structure is not involved in activation of the protein, but nevertheless is crucial for its overall structural stability. In analogy to NhaA, the β sheet structure probably forms the main contact between monomers, but in contrast to NhaA the monomer-monomer interaction is not essential for its activity. The inactive state of the detergent-solubilised protein, having a higher fraction of unordered structure, resulted in higher 1H/2H exchange than the active state. Comparing this with the results of 2D crystals allowed the localisation of unordered structure in the inactive state to be on the outside regions of the protein molecule. pH-induced difference spectra showed that activation is accompanied by helicalisation of the protein as well as by protonation of glutamic- and/or aspartic acid side chains, and is independent of sample preparation. The results of NhaA and MjNhaP1 demonstrated that in both cases the activation is associated with conformational and protonation changes of amino acids. The secondary structure changes of both proteins are similar during activation, but clearly distinguishable for inactivation. The observed pH-induced structural changes of NhaA and MjNhaP1 are proven with the mutants G338S and R347A, which do not show pH-dependent activity. The difference spectra of the mutants help to assign IR bands due to activation of the protein