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Organisational slack, corporate reputation and financial performance
No full textThis discussion paper aims to fill the gap left by the latest research on organisational slack that has been focused on emerging economies or on a single company or on a single industry. Senior executives’ perceptions that contribute to a measure of corporate reputation are tested as a proxy measure of unabsorbed slack. Disaggregating the components that make up reputation enables the perceptions of a company’s ‘ability to innovate’ and how efficiently they ‘use their corporate assets’ to also be tested as measures of unabsorbed, perceptual or discretionary slack. The impact of these variables is considered in terms of company performance
Towards minimizing the energy of slack variables for binary classification
No full text20.09.13 KB. Ok to add to spiral, author says conference already available online.This paper presents a binary classification algorithm that is based on the minimization of the energy of slack variables, called the Mean Squared Slack (MSS). A novel kernel extension is proposed which includes the withholding of just a subset of input patterns that are misclassified during training. The later leads to a time and memory efficient system that converges in a few iterations. Two datasets are exploited for performance evaluation, namely the adult and the vertebral column dataset. Experimental results demonstrate the effectiveness of the proposed algorithm with respect to computation time and scalability. Accuracy is also high. In specific, it equals 84.951% for the adult dataset and 91.935%, for the vertebral column dataset, outperforming state-of-the-art methods. © 2012 EURASIP
Global Slack and Domestic Inflation Rates: A Structural Investigation for G-7 Countries
No full textRecent papers have argued that one implication of globalization is that domestic inflation rates may have now become more a function of ``global", rather than domestic, economic conditions, as postulated by closed-economy Phillips curves. This paper aims to assess the empirical importance of global output in determining domestic inflation rates by estimating a structural model for a sample of G-7 economies. The model can capture the potential effects of global output fluctuations on both the aggregate supply and the aggregate demand relations in the economy and it is estimated using full-information Bayesian methods. The empirical results reveal a significant effect of global output on aggregate demand in most countries. Through this channel, global economic conditions can indirectly affect inflation. The results, instead, do not seem to provide evidence in favor of altering domestic Phillips curves to include global slack as an additional driving variable for inflation.Globalization; Global Slack; Inflation Dynamics; Phillips Curve; Bayesian Estimation
Slack matrices, k-products, and 2-level polytopes
No full textIn this paper, we study algorithmic questions concerning products of matrices and their consequences for recognition algorithms for polyhedra.
The 1-product of matrices S1, S2 is a matrix whose columns are the concatenation of each column of S1 with each column of S2. The k-product generalizes the 1-product, by taking as input two matrices S1,S2 together with k−1 special rows of each of those matrices, and outputting a certain composition of S1,S2.
Our study is motivated by a close link between the 1-product of matrices and the Cartesian product of polytopes, and more generally between the k-product of matrices and the glued product of polytopes. These connections rely on the concept of slack matrix, which gives an algebraic representation of classes of affinely equivalent polytopes. The slack matrix recognition problem is the problem of determining whether a given matrix is a slack matrix. This is an intriguing problem whose complexity is unknown. Our algorithm reduces the problem to instances which cannot be expressed as k-products of smaller matrices.
In the second part of the paper, we give a combinatorial interpretation of k-products for two well-known classes of polytopes: 2-level matroid base polytopes and stable set polytopes of perfect graphs. We also show that the slack matrix recognition problem is polynomial-time solvable for such polytopes. Those two classes are special cases of 2-level polytopes, for which we conjecture that the slack matrix recognition problem is polynomial-time solvable
Slack Time and Innovation
No full textThe relationship between slack resources and innovation is complex, with the literature linking slack to both breakthrough innovations and resource misallocation. We reconcile these conflicting views by focusing on a novel mechanism: the role slack time plays in the endogenous allocation of time and effort to innovative projects. We develop a theoretical model that distinguishes between periods of high- (work weeks) versus low- (break weeks) opportunity costs of time. Low-opportunity cost time during break weeks may induce (1) lower quality ideas to be developed (a selection effect); (2) more effort to be applied for any given idea quality (an effort effect); and (3) an increase in the use of teams because scheduling is less constrained (a coordination effect). As a result, the effect of an increase in slack time on innovative outcomes is ambiguous, because the selection effect may induce more low-quality ideas, whereas the effort and coordination effect may lead to more high-quality, complex ideas. We test this framework using data on college breaks and on 165,410 Kickstarter projects across the United States. Consistent with our predictions, during university breaks, more projects are posted in the focal regions, and the increase is largest for projects of either very high or very low quality. Furthermore, projects posted during breaks are more complex, and involve larger teams with diverse skills. We discuss the implications for the design of policies on slack time
Wetwang Slack : an Iron Age cemetery on the Yorkshire Wolds.
No full textThis work is an examination of a large Iron Age cemetery which was
excavated by the writer at Wetwang Slack on the Yorkshire Wolds between
1975 and 1979.
The chief features which make this site exceptional are the large number
of inhumation burials involved (446), the unusually good stratigraphical
evidence for the relative chronology of the cemetery, and the extensive
remains of the contemporary settlement which the cemetery served.
In an introduction British Iron Age studies and the extent of
archaeological research in the region are summarised to indicate the
extent of knowledge at the time when excavations were underway.
Part 1 describes the circumstances of excavation and the location of the
site, isolates the ditched enclosures and graves which were the principle
constituents of the cemetery, and details the types of burial which were
encountered.
In Part 2 the evidence for a relative chronology of the cemetery is
considered at length and from the stratification, the artifacts, and some
changing characteristics recognisable among the burials and enclosures
different chronological horizons can be recognised. Unlike artifacts
found on settlement sites those found in graves can reasonably be assumed
to have been in use up until the time of their burial. For this reason
the cemetery provides a much needed guide to the relative date of
artifacts, many of which are types with a widespread distribution.
The skeletal evidence is examined in Part 3 for evidence of physical
type, disease etc. and the data is searched for signs of social
organisation.
The settlement evidence in the form of buildings, land boundaries and
trackways is described in Part 4 and the inter-relationship of burials
and settlement is examined. Finally, the cultural affinities of the whole complex with the East
Yorkshire "Arras Culture" and other traditions of Iron Age Britain are
sought and an interpretation is given which identifies population growth
as a principle underlying cause of changes which took place in society,
settlement patterns and economy in the region during the Iron Age
A Forensic Examination of Database Slack
No full textThis research includes an examination and analysis of the phenomenon of database slack. Database forensics is an underexplored subfield of Digital Forensics, and the lack of research is becoming more important with every breach and theft of data. A small amount of research exists in the literature regarding database slack. This exploratory work examined what partial records of forensic significance can be found in database slack. A series of experiments performed update and delete transactions upon data in a PostgreSQL database, which created database slack. Patterns of hexadecimal indicators for database slack in the file system were found and analyzed. Despite limitations in the experiments, the results indicated that partial records of forensic significance are found in database slack. Significantly, partial records found in database slack may aid a forensic investigation of a database breach. The details of the hexadecimal patterns of the database slack fill in gaps in the literature, the impact of log findings on an investigation was shown, and complexity aspects back up existing parts of database forensics research. This research helped to lessen the dearth of work in the area of database forensics as well as database slack
Einfluss des Na+-aktivierten K+-Kanals Slack auf den myokardialen Ischämie- und Reperfusionsschaden
No full textIschämische Herzerkrankungen zählen zu den führenden Ursachen für Morbidität und Sterblichkeit weltweit. Im Verlauf eines akuten Myokardinfarkts (MI) kommt es, bedingt durch den Gefäßverschluss eines oder mehrerer Koronargefäße und der damit einhergehenden Minderdurchblutung des betroffenen Herzareals, zu einer irreversiblen Myokardschädigung. Die zeitnahe Reperfusionstherapie ist die einzige Therapiemöglichkeit um den ischämischen Schaden zu limitieren. Bislang stehen keine zusätzlichen pharmakologischen Therapieoptionen zur Verfügung um die Progredienz der kardiomyozytären Schädigung während der Infarktzeit zu reduzieren.
Kardiale Kalium (K+)-Kanäle tragen zur physiologischen Regulation des Ruhemembranpotentials und der Gestaltung der Erregungsleitung am Herzen bei. Im Tiermodell zeigte sich zudem, dass mithilfe von mechanischen und pharmakologischen Konditionierungsansätzen, u. a. durch die Aktivierung distinkter K+-Kanäle, der kardiale Ischämie- und Reperfusions (I/R)-Schaden abgeschwächt werden kann. Eine protektive Relevanz unter Ischämie/Hypoxie wird auch für den Natrium (Na+)-aktivierten K+-Kanal Slack (aka Slo2.2, KCNT1) postuliert, der aufgrund der zytotoxischen Akkumulation intrazellulärer Na+-Ionen ([Na+]i) bei myokardialer Ischämie aktiviert werden könnte. Der resultierende K+-Efflux könnte somit zu einer Stabilisierung des Membranpotentials im Kardiomyozyt und letztlich zur Kardioprotektion bei MI beitragen.
Gegenstand der vorliegenden Doktorarbeit war es, die Rolle des Slack-Kanals bei akutem MI in vivo zu untersuchen. Eine signifikant erhöhte Vulnerabilität im in vivo MI-Modell zeigte sich sowohl in globalen als auch in Kardiomyozyten-spezifischen Slack-Knockoutmäusen gegenüber den jeweiligen Kontrolltieren. Die Deletion des kardiomyozytären Slack-Kanals (CM Slack) führte zudem zu einer verminderten Kardioprotektion nach mechanischer Konditionierung. In pharmakologischer Herangehensweise konnte ein Zusammenhang zwischen CM Slack und dem Herzschutz-relevanten Guanylylzyklase (GC)/zyklisches Guanosin-3‘5‘-monophosphat (cGMP)/cGMP-abhängige Proteinkinase Typ I (cGKI)-Signalweg ausgeschlossen werden. Hingegen war die Schadensprävention durch mechanische Konditionierung bei MI u. a. auf die Wechselwirkung von CM Slack mit dem mitochondrialen Adenosintriphosphat (ATP)-abhängigen K+-Kanal (mitoKATP) zurückzuführen. Auch bei Betrachtung der Langzeitfolgen nach MI zeigte sich CM Slack von Bedeutung für den Erhalt der linksventrikulären Herzfunktion. Ergänzende biochemische, elektrophysiologische und Fluoreszenz-basierte Untersuchungen an murinen Kardiomyozyten und HEK293-hKCNT1-Surrogatzellen bestätigen die kardiale Expression des Slack-Kanals sowie dessen Einflussnahme auf die Regulation der intrazellulären K+-Ionenhomöostase und das elektrochemische Gleichgewicht der Zelle. Zusammenfassend konnte im Rahmen dieser Dissertation erstmals eine bedeutende Rolle des Slack-Kanals bei I/R am Herzen gezeigt werden
On the slack phenomena and snap force in tethers of submerged floating tunnels under wave conditions
No full textUnder severe sea wave conditions, the mooring tethers of submerged floating tunnel (SFT) might go slack. It may cause the structure failure during the service lifetime of SFT. The paper investigated SFT dynamics when going through tether slacking and the related snap force under wave conditions. Besides the nonlinearity of fluid drag and of structural geometry for a relative large structure displacement, the problem is characterized by the nonlinearity due to the discontinuity in axial stiffness of the tethers. To include these nonlinearities, the method of Lagrange energy is used to build the governing equations of SFT motion, and a bilinear oscillator is introduced to simulate the mooring tether operating in an alternating slack-taut state. The sensitivities of the occurrence of tether slacking to wave height and wave period are investigated. Results show that at a large wave height SFT tether will go slack and snap force occurs. SFT responses are categorized into three types of state according to the dynamic response characteristics of tether tension. Effects of two fundamental structure parameters, buoyancy-weight ratio (BWR) and inclined mooring angle (IMA), on the dynamic responses of SFT are analyzed. A slack-taut map of SFT tethers is built. It intuitively describes the occurrences of slack and snap force with different combinations of the two parameters. An analytical approach for slack prediction by deriving the slack criterion is provided to reveal the mechanism of the presented slack-taut map. By present research, the authors tried to make their effort to provide an alternative philosophy for SFT structural design on concerning preventing the occurrence of tether slacking and snap force. (C) 2011 Elsevier Ltd. All rights reserved
Factors regulating sediment fluxes over an engineered foredune and adjacent dune slack
No full textThis study aims to identify and understand the annual scale sediment transport patterns in a fully engineered dune-dune slack system that was created from seabed sediments for grey dune and moist dune slack habitat creation at the Delfland coast (the Netherlands). The annual morphological development was analysed using LiDAR elevation data. Daily aeolian sediment transport was simulated across the foredune and in the adjacent dune slack, using the numerical aeolian sediment transport model AeoLiS. All simulated transport events were combined to reveal how aeolian sediment transport behaves on an annual scale. Planting two continuous strips of marram grass along the top of the foredune induced rapid growth of the foredune, while limiting sediment supply to the dune slack. The armouring layer of shells that formed at the surface of the engineered topography, functioned as a supply-limiting factor and restricted the sediment entrainment and deflation of the dune slack. Therefore, the formation of a moist dune slack habitat may take longer for this engineered case than in a natural case with similar boundary conditions
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