958 research outputs found

    Detection of nitric oxide pollution

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    Studies of absorption spectra enhancement of certain atomic and molecular species inserter in dye-laser cavities have indicated that nitric oxide can be determined at low concentrations. Absorption coefficient of small amounts of nitric oxide in intra-laser-cavity absorption cell containing helium is enhanced by more than two orders of magnitude

    Nicaragua und Puerto Rico

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    Ich bin drei Jahre nach einander mit dem Gettysburg College Chor gereist. Im Frühling 2006 habe ich Nicaragua besucht und vom 1. bis 9. März 2008 war ich in Puerto Rico. Beide Länder sind schon, aber es gibt viele Unterschiede zwischen Nicaragua und Puerto Rico. [excerpt

    Measuring Investment Distortions when Risk-Averse Managers Decide Whether to Undertake Risky Projects

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    This paper examines distortions in corporate investment decisions when a new project changes firm risk. It presents a dynamic model in which a self-interested, risk-averse manager makes investment decisions at a levered firm. The model, calibrated using data from public firms, is used to estimate the magnitude of distortions in investment decisions. Despite potential wealth transfers from debtholders, managers compensated with equity prefer safe projects to risky ones. Important factors in this decision are the expected changes in the values of future tax shields and bankruptcy costs when firm risk changes. We also evaluate the extent to which this effect varies with firm leverage, managerial risk aversion, managerial non-firm wealth, project size, debt duration, and the structure of management compensation packages.

    Automation and data processing with the immucor Galileo (R) system in a university blood bank

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    Background: The implementation of automated techniques improves the workflow and quality of immuno-hematological results. The workflows of our university blood bank were reviewed during the implementation of an automated immunohematological testing system. Methods: Work impact of blood grouping and subgrouping, cross- matching and antibody search using the Immucor Galileo system was compared to the previous used standard manual and semi- automated methods. Results: The redesign of our workflow did not achieve a significant reduction of the specimen's working process time, the operator's time however was reduced by 23%. Corresponding results were achieved for blood grouping, Rhesus typing, antibody screen and for autocontrol when changing from two semi- automated to the Galileo system. Because of the higher sensitivity of the Immucor antibody detection system, the rate of the initial positive antibody screens rose from 4 to 6% Conclusion: The Immucor Galileo system automates routine blood bank testing with high reliability, specificity and higher sensitivity compared to our previous used standard manual and semi- automated methods

    Desynchronization and Wave Pattern Formation in MPI-Parallel and Hybrid Memory-Bound Programs

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    Analytic, first-principles performance modeling of distributed-memory parallel codes is notoriously imprecise. Even for applications with extremely regular and homogeneous compute-communicate phases, simply adding communication time to computation time does often not yield a satisfactory prediction of parallel runtime due to deviations from the expected simple lockstep pattern caused by system noise, variations in communication time, and inherent load imbalance. In this paper, we highlight the specific cases of provoked and spontaneous desynchronization of memory-bound, bulk-synchronous pure MPI and hybrid MPI+OpenMP programs. Using simple microbenchmarks we observe that although desynchronization can introduce increased waiting time per process, it does not necessarily cause lower resource utilization but can lead to an increase in available bandwidth per core. In case of significant communication overhead, even natural noise can shove the system into a state of automatic overlap of communication and computation, improving the overall time to solution. The saturation point, i.e., the number of processes per memory domain required to achieve full memory bandwidth, is pivotal in the dynamics of this process and the emerging stable wave pattern. We also demonstrate how hybrid MPI-OpenMP programming can prevent desirable desynchronization by eliminating the bandwidth bottleneck among processes. A Chebyshev filter diagonalization application is used to demonstrate some of the observed effects in a realistic setting.Comment: 18 pages, 8 figure

    Multiple agency perspective, family control, and private information abuse in an emerging economy

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    Using a comprehensive sample of listed companies in Hong Kong this paper investigates how family control affects private information abuses and firm performance in emerging economies. We combine research on stock market microstructure with more recent studies of multiple agency perspectives and argue that family ownership and control over the board increases the risk of private information abuse. This, in turn, has a negative impact on stock market performance. Family control is associated with an incentive to distort information disclosure to minority shareholders and obtain private benefits of control. However, the multiple agency roles of controlling families may have different governance properties in terms of investors’ perceptions of private information abuse. These findings contribute to our understanding of the conflicting evidence on the governance role of family control within a multiple agency perspectiv

    Regulation and the Evolution of Corporate Boards: Monitoring, Advising or Window Dressing?

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    An earlier version of this paper was entitled “Deregulation and Board Composition: Evidence on the Value of the Revolving Door.”It is generally agreed that boards are endogenously determined institutions that serve both oversight and advisory roles in a firm. While the oversight role of boards has been extensively studied, relatively few studies have examined the advisory role of corporate boards. We examine the participation of political directors on the boards of natural gas companies between 1930 and 1998. We focus on the expansion of federal regulation of the natural gas industry in 1938 and 1954 and subsequent partial deregulation in 1986. Using data sets covering the periods from 1930 to 1990 and 1978 to 1998, we test whether regulation and deregulation altered the composition of companies' boards as the firms' environment changed. In particular, did regulation cause an increase and deregulation a decrease in the number of political directors on corporate boards? We find evidence that the number of political directors increases as firms shift from market to political competition. Specifically, the regulation of natural gas is associated with an increase in the number of political directors and deregulation is associated with a decrease in the number of political directors on boards
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