Finite Domain Bounds Consistency Revisited

A widely adopted approach to solving constraint satisfaction problems combines systematic tree search with constraint propagation for pruning the search space. Constraint propagation is performed by propagators implementing a certain notion of consistency. Bounds consistency is the method of choice for building propagators for arithmetic constraints and several global constraints in the finite integer domain. However, there has been some confusion in the definition of bounds consistency. In this paper we clarify the differences and similarities among the three commonly used notions of bounds consistency.Comment: 12 page

Organizational Culture and Corporate Innovation

This paper examines corporate innovation with a view to determine its relationship with organizational culture. A critical review of extant literature suggests clearly that innovation matters and it is important for achieving competitive advantage in a highly competitive market. But in achieving corporate innovation, organizational culture plays a very significant role because innovation requires very different business conditions, skills, structures and processes. Previous studies have shown that corporate innovation is influenced either positively or negatively by organizational culture. While some constructs of organizational culture serve as impediments to corporate innovation, others serve as support to corporate innovation. It is therefore recommended that for corporate innovation to strive, managers should be extremely careful in keeping the right mix of cultural traits.Key words: Organizational culture, corporate innovation, creativit

Taxonomic composition and growth rates of phytoplankton assemblages at the Subtropical Convergence east of New Zealand

Off the eastern coast of New Zealand, warm, saline, nutrient-poor Subtropical Waters (STW) are separated from. cool, fresher, relatively nutrient-rich Sub-Antarctic Waters (SAW) by the Subtropical Convergence (STC). The Chatham Rise, a submarine rise, restricts. the latitudinal movement of the STC as well as mixing of STW and SAW Due to this restriction, this sector of the STC is characterized by sharp gradients in temperature, macro-(nitrate, silicate and phosphate) and micro- (iron) nutrient concentrations. Shipboard incubations were conducted during austral spring 2000 and 2001 to test the hypothesis that these gradients affect the taxonomic composition and/or growth rates of phytoplankton on either side of and at the STC. Maximum chlorophyll a concentrations during 2000 were 0.39 mu g L-1 but were an order of magnitude higher in 2001. During both years, STC phytoplankton were dominated by diatoms (77% of the to a chlorophyll a during austral spring 2000 and 70% during spring 2001), whereas crytopytes and prasinopytes dominated STW,assemblages (27 and 36% during 2000, and 63 and 17% during 2001). Chlorophyll in the SAW was dominated by procaryotes and photosynthetic nanoflagellates during 2000 (17% procaryotes. 68% nanoflagellates), and by diatoms during the austral spring 2001 cruise (53%). Growth rates of the phytoplankton assemblage were determined by C-14-labeling of chlorophyll a and photosynthetic pigments. During 2000, temperature-normalized growth rates were near maximal ai the STC, and decreased on average to less than half of the maximum north and south of that front, whereas in 2001 both absolute and relative growth rates were low at all stations. Growth rates did not closely parallel biomass of the various taxa, suggesting that nutrient limitation and/or grazing were significantly impacting standing stocks. It appeared that growth was strongly influenced by nutrients and light, but that biomass was more strongly influenced by grazing The STC is a globally important region of enhanced biomass and productivity; however, the phytoplankton assemblage reflects control by both top-down and bottom-up processes that makes a predictive understanding of the area\u27s biogeochemical cycles extremely difficult

On the exit statistics theorem of many particle quantum scattering

We review the foundations of the scattering formalism for one particle potential scattering and discuss the generalization to the simplest case of many non interacting particles. We point out that the "straight path motion" of the particles, which is achieved in the scattering regime, is at the heart of the crossing statistics of surfaces, which should be thought of as detector surfaces. We sketch a proof of the relevant version of the many particle flux across surfaces theorem and discuss what needs to be proven for the foundations of scattering theory in this context.Comment: 15 pages, 4 figures; to appear in the proceedings of the conference "Multiscale methods in Quantum Mechanics", Accademia dei Lincei, Rome, December 16-20, 200

An Analysis of Performance Interference Effects on Energy-Efficiency of Virtualized Cloud Environments

Co-allocated workloads in a virtualized computing environment often have to compete for resources, thereby suffering from performance interference. While this phenomenon has a direct impact on the Quality of Service provided to customers, it also changes the patterns of resource utilization and reduces the amount of work per Watt consumed. Unfortunately, there has been only limited research into how performance interference affects energy-efficiency of servers in such environments. In reality, there is a highly dynamic and complicated correlation among resource utilization, performance interference and energy-efficiency. This paper presents a comprehensive analysis that quantifies the negative impact of performance interference on the energy-efficiency of virtualized servers. Our analysis methodology takes into account the heterogeneous workload characteristics identified from a real Cloud environment. In particular, we investigate the impact due to different workload type combinations and develop a method for approximating the levels of performance interference and energy-efficiency degradation. The proposed method is based on profiles of pair combinations of existing workload types and the patterns derived from the analysis. Our experimental results reveal a non-linear relationship between the increase in interference and the reduction in energy-efficiency as well as an average precision within +/-5% of error margin for the estimation of both parameters. These findings provide vital information for research into dynamic trade-offs between resource utilization, performance, and energy-efficiency of a data center

Second trimester hepatic rupture in a 35 year old nulliparous woman with HELLP syndrome: a case report

The HELLP syndrome (haemolysis, elevated liver blood tests and low platelets) is a serious complication in pregnancy characterized by haemolysis, elevated liver enzymes and low platelet count occurring in 0.5 to 0.9% of all pregnancies and in 10–20% of cases with severe preeclampsia. Hepatic capsular rupture is a rare yet dramatic complication of HELLP syndrome. The majority of cases occur in multiparous women over the age of 30. Classically it presents with acute onset right upper quadrant pain in the presence of constitutional symptoms such as vomiting and pyrexia. However, symptoms and signs are usually non specific. Spontaneous hepatic rupture can be preceded by signs of hypovolaemic shock; yet the diagnosis is infrequently made prior to emergent laparotomy. We present the case of a 35 year old nulliparous woman with a second trimester gestational hepatic rupture associated with HELLP syndrome. We briefly discuss the aetiology, diagnostic difficulties and treatment options associated with this rare presentation

Post-traumatic tension faecopneumothorax in a young male: case report

Diaphragmatic rupture due to trauma is both well recognised and uncommon. The difficulties in diagnosing traumatic diaphragmatic rupture at the first admission are the most common causes of latent morbidity and mortality. Herniation of the abdominal viscera is the most common sequel with strangulation and perforation the most serious complication. This case outlines the delayed presentation of diaphragmatic rupture and herniation presenting as an acute tension faecopneumothorax. We review the relevant literature, with particular emphasis on the difficulties in diagnosis at presentation

Improved energy-efficiency in cloud datacenters with interference-aware virtual machine placement

Virtualization is one of the main technologies used for improving resource efficiency in datacenters; it allows the deployment of co-existing computing environments over the same hardware infrastructure. However, the co-existing of environments — along with management inefficiencies — often creates scenarios of high-competition for resources between running workloads, leading to performance degradation. This phenomenon is known as Performance Interference, and introduces a non-negligible overhead that affects both a datacenter's Quality of Service and its energy-efficiency. This paper introduces a novel approach to workload allocation that improves energy-efficiency in Cloud datacenters by taking into account their workload heterogeneity. We analyze the impact of performance interference on energy-efficiency using workload characteristics identified from a real Cloud environment, and develop a model that implements various decision-making techniques intelligently to select the best workload host according to its internal interference level. Our experimental results show reductions in interference by 27.5% and increased energy-efficiency up to 15% in contrast to current mechanisms for workload allocation