NEGO — Group decision support system

There are two major frameworks for decision making: maximizing and satisficing. A combination of both may be used to describe group decision making (GDM). In the satisficing approach, decision makers (DMs) formulate aspiriation levels or demands which take the form of constraints. Choosing from among different decisions, DMs take into account their preferences or wants, which take the form of objective functions.GDM is divided into two stages: first, each DM makes a decision, and second, DMs negotiate so as to achieve a compromise decision. Negotiating is an iterative process. Negotiations are completed when all demands have been met.The group decision support system “NEGO” assists DMs in finding a compromise. It has been used for solving a GDM problem at the corporate level and is currently utilized in management courses.     

Optimizing main-memory join on modern hardware

In the past decade, the exponential growth in commodity CPU's speed has far outpaced advances in memory latency. A second trend is that CPU performance advances are not only brought by increased clock rates, but also by increasing parallelism inside the CPU. Current database systems have not yet adapted to these trends and show poor utilization of both CPU and memory resources on current hardware. In this paper, we show how these resources can be optimized for large joins and translate these insights into guidelines for future database architectures, encompassing data structures, algorithms, cost modeling and implementation. In particular, we discuss how vertically fragmented data structures optimize cache performance on sequential data access. On the algorithmic side, we refine the partitioned hash-join with a new partitioning algorithm called "radix-cluster", which is specifically designed to optimize memory access. The performance of this algorithm is quantified using a detailed analytical model that incorporates memory access costs in terms of a limited number of parameters, such as cache sizes and miss penalties. We also present a calibration tool that extracts such parameters automatically from any computer hardware. The accuracy of our models is proven by exhaustive experiments conducted with the Monet database system on three different hardware platforms. Finally, we investigate the effect of implementation techniques that optimize CPU resource usage. Our experiments show that large joins can be accelerated almost an order of magnitude on modern RISC hardware when both memory and CPU resources are optimized     

Aluminium alloy based hydrogen storage tank operated with sodium aluminium hexahydride Na3AlH6

Here we present the development of an aluminium alloy based hydrogen storage tank, charged with Ti-doped sodium aluminium hexahydride Na₃AlH₆. This hydride has a theoretical hydrogen storage capacity of 3 mass-% and can be operated at lower pressure compared to sodium alanate NaAlH₄. The tank was made of aluminium alloy EN AW 6082 T6. The heat transfer was realised through an oil flow in a bayonet heat exchanger, manufactured by extrusion moulding from aluminium alloy EN AW 6060 T6. Na₃AlH₆ is prepared from 4 mol-% TiCl₃ doped sodium aluminium tetrahydride NaAlH₄ by addition of two moles of sodium hydride NaH in ball milling process. The hydrogen storage tank was filled with 213 g of doped Na₃AlH₆ in dehydrogenated state. Maximum of 3.6 g (1.7 mass-% of the hydride mass) of hydrogen was released from the hydride at approximately 450 K and the same hydrogen mass was consumed at 2.5 MPa hydrogenation pressure. 45 cycle tests (rehydrogenation and dehydrogenation) were carried out without any failure of the tank or its components. Operation of the tank under real conditions indicated the possibility for applications with stationary HT-PEM fuel cell systems.     

A Bayesian framework for automated cardiovascular risk scoring on standard lumbar radiographs

We present a fully automated framework for scoring a patient's risk of cardiovascular disease (CVD) and mortality from a standard lateral radiograph of the lumbar aorta. The framework segments abdominal aortic calcifications for computing a CVD risk score and performs a survival analysis to validate the score. Since the aorta is invisible on X-ray images, its position is reasoned from 1) the shape and location of the lumbar vertebrae and 2) the location, shape, and orientation of potential calcifications. The proposed framework follows the principle of Bayesian inference, which has several advantages in the complex task of segmenting aortic calcifications. Bayesian modeling allows us to compute CVD risk scores conditioned on the seen calcifications by formulating distributions, dependencies, and constraints on the unknown parameters. We evaluate the framework on two datasets consisting of 351 and 462 standard lumbar radiographs, respectively. Promising results indicate that the framework has potential applications in diagnosis, treatment planning, and the study of drug effects related to CVD.     

Postoperative lens position preoperatively determined by Scheimpflug photography

The position of the artificial lens has an important influence on refractive power calculation. We compared the position of the crystalline lens with that of the artificial lens after cataract surgery by means of Scheimpflug photography. A difference in position of approximately 0.8 mm in the anterior direction could be determined.     

Cardiovascular effects of verapamil enantiomer combinations in conscious dogs

We examined the systemic and coronary hemodynamic effects of five combinations of R- and S-verapamil enantiomers (R/S; 100/0, 90/10, 80/20, 50/50, and 20/80%, respectively) in conscious dogs chronically instrumented for measurement of aortic and LV pressure, +dP/dt, subendocardial segment length, coronary blood flow velocity, and aortic blood flow. Dogs received escalating doses (0.1, 0.2, and 0.4 mg kg(-1)) of each verapamil combination over 2 min at 30 min intervals on different experimental days and peak changes in hemodynamics were recorded 2 min after each dose. All verapamil combinations increased heart rate, mean aortic blood flow, and coronary blood flow velocity and decreased calculated systemic and coronary vascular resistance. Alterations in coronary hemodynamics were most pronounced with 20/80 R/S verapamil. Racemic and 20/80 R/S verapamil decreased mean arterial and left ventricular systolic pressure, in contrast to combinations with greater concentrations of the R enantiomer. Left ventricular function was unchanged during administration of 100/0, 90/10, and 80/20 R/S verapamil. Direct negative inotropic and lusitropic effects occurred with 50/50 and 20/80 R/S verapamil. The high dose of 20/80 R/S verapamil also increased left ventricular end-diastolic pressure and the regional chamber stiffness constant, consistent with diastolic dysfunction. The results indicate that combinations of R- and S-verapamil produce differential hemodynamic and left ventricular functional effects in conscious, unsedated dogs that are dependent on the relative ratio of these enantiomers.     

A division of labor between nouns and verbs in the representation of motion.

This study examines the association of nouns and verbs with 2 different kinds of motion. Extrinsic motion is the motion of 1 object with respect to another object, whereas intrinsic motion is the motion of an object (or its parts) defined with respect to itself. Several experiments are reported that compare the association of these types of motion with novel nouns and verbs. Adult participants demonstrated a bias to associate verbs with extrinsic motion to a greater extent than intrinsic motion and a bias to associate nouns with intrinsic motion to a greater extent than extrinsic motion. These results suggest a division of labor between nouns and verbs, with verbs specialized to convey relational information, whereas nouns are specialized to convey information about individual objects. The distinction between intrinsic and extrinsic motion may be related to the neuroanatomical distinction between the "what" and "where" systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bücherschau

Ohne Zusammenfassung VDI     

Postoperative complications of penetrating keratoplasty in herpes infected eyes. Differential diagnosis, therapy and prognostic significance

BACKGROUND: We evaluated in this retrospective study the impact of our diagnostic and therapeutic regimens--as illustrated by typical clinical pictures--on the frequency and prognostic values of postkeratoplasty complications in herpes eyes. PATIENTS AND METHODS: Between November 1986 and June 1994, 112 penetrating keratoplasties (KPS) in herpes eyes were performed, 76 as planned and 36 as emergency procedures. The results were compared with 646 KPS with normal risk. For statistical analysis we used the Kaplan-Meier estimation, and statistical significance was tested by the log rank test. RESULTS: After 6 years, 75% of the grafts in the planned herpes group, 86% of the à chaud KPS and 76% of the grafts of the normal-risk group were still clear without significant differences between these three groups. Fifty-four percent of the planned KPS in herpes eyes, 73% of the à chaud KPS in herpes eyes and 80% of the normal-risk KPS experienced no immune reaction, with both herpes groups showing significantly more reactions than the normal-risk KPS. There was, however, no significant difference in immune reactions between the two herpes groups. The percentage of grafts with recurrence of herpes simplex virus infection after 6 years was significantly higher in the à chaud group. CONCLUSIONS: With proper postoperative care and optimal management of immunologic and virologic complications--but only with this!--the prognosis of penetrating keratoplasties in herpes eyes equals that of normal risk eyes. An particular, the prognosis is not dependent on whether surgery was performed as a planned or as an emergency procedure.