高密度配线架选择指南

康普在去年推出新型超高密度配线架,可以在1U的机架空间内提供144个LC连接密度.对于某些用户来说,如此超高密度的好处多多,因为这些用户机房内的导向器几乎占据了机柜中所有的可用机架空间.     

Cost-effectiveness analysis of rivaroxaban for treatment and secondary prevention of venous thromboembolism in the Netherlands

Background: Until recently, standard treatment of venous thromboembolism (VTE) concerned a combination of short-term low-molecular-weight heparin (LMWH) and long-term vitamin-K antagonist (VKA). Risk of bleeding and the requirement for regular anticoagulation monitoring are, however, limiting their use. Rivaroxaban is a novel oral anticoagulant associated with a significantly lower risk of major bleeds (hazard ratio?=?0.54, 95% confidence interval?=?0.37–0.79) compared to LMWH/VKA therapy, and does not require regular anticoagulation monitoring.

Aims: To evaluate the health economic consequences of treating acute VTE patients with rivaroxaban compared to treatment with LMWH/VKA, viewed from the Dutch societal perspective.

Methods: A life-time Markov model was populated with the findings of the EINSTEIN phase III clinical trial to analyze cost-effectiveness of rivaroxaban therapy in treatment and prevention of VTE from a Dutch societal perspective. Primary model outcomes were total and incremental quality-adjusted life years (QALYs), as well as life expectancy and costs.

Results: Over a patient’s lifetime, rivaroxaban was shown to be dominant, with health gains of 0.047 QALYs and cost savings of €304 compared to LMWH/VKA therapy. Dominance was robustly present in all sensitivity analyses. Major drivers of the differences between the two treatment arms were related to anticoagulation monitoring (medical costs, travel costs, and loss of productivity) and the occurrence of major bleeds.

Conclusion: Rivaroxaban treatment of patients with venous thromboembolism results in health gains and cost savings compared to LMWH/VKA therapy. This conclusion holds for the Dutch setting, both for the societal perspective, as well as the healthcare perspective.     

Modelling Inflation Volatility

This paper discusses estimation of US inflation volatility using time‐varying parameter models, in particular whether it should be modelled as a stationary or random walk stochastic process. Specifying inflation volatility as an unbounded process, as implied by the random walk, conflicts with priors beliefs, yet a stationary process cannot capture the low‐frequency behaviour commonly observed in estimates of volatility. We therefore propose an alternative model with a change‐point process in the volatility that allows for switches between stationary models to capture changes in the level and dynamics over the past 40 years. To accommodate the stationarity restriction, we develop a new representation that is equivalent to our model but is computationally more efficient. All models produce effectively identical estimates of volatility, but the change‐point model provides more information on the level and persistence of volatility and the probabilities of changes. For example, we find a few well‐defined switches in the volatility process and, interestingly, these switches line up well with economic slowdowns or changes of the Federal Reserve Chair. Moreover, a decomposition of inflation shocks into permanent and transitory components shows that a spike in volatility in the late 2000s was entirely on the transitory side and characterized by a rise above its long‐run mean level during a period of higher persistence. Copyright © 2015 John Wiley & Sons, Ltd.     

Are stricter investment rules contagious? Host country competition for foreign direct investment through international agreements

We argue that competitive diffusion is a driver of the trend toward international investment agreements with stricter investment rules, namely defensive moves of developing countries concerned about foreign direct investment (FDI) diversion in favor of competing host countries. Accounting for spatial dependence in the formation of bilateral investment treaties and preferential trade agreements that contain investment provisions, we find that the increase in agreements with stricter provisions on investor-to-state dispute settlement and pre-establishment national treatment is a contagious process. Specifically, a developing country is more likely to sign an agreement with weak investment provisions if other developing countries that compete for FDI from the same developed country have previously signed agreements with similarly weak provisions. Conversely, contagion in agreements with strong provisions exclusively derives from agreements with strong provisions that other FDI-competing developing countries have previously signed with a specific developed source country of FDI.     

Integrating partitioned prices via computational estimation

This paper introduces computational estimation to the literature on consumers’ numerical cognition. Computational estimation involves simplifying an arithmetic problem via mathematical procedures to produce an approximate answer. Employing calculation knowledge and approximation together, consumers are likely to use computational estimation as it is relatively accurate while saving cognitive effort compared to calculating values. Three studies applied to partitioned prices in the form of a base price and a percentage discount, demonstrate that when faced with this numeric integration task, the strategy consumers undertake is dependent on the characteristics of the numerals with discounts that are round or close to round being associated with greater use of computational estimation. Further, when employing computational estimation, consumers arrive at more accurate, and lower, price estimates in which they place more confidence than when using alternative an integration strategy. As a result, discounts that are near a round value are preferred to those that are not; a result that is dependent upon the use of computational estimation.     

Increasing consumer well-being: risk as potential driver of happiness

This article investigates the relation between risk and individual well-being. We propose a theoretical model of happiness that makes a distinction between ex ante evaluations of happiness and ex post assessments. The main assumptions of the model are tested through three studies based on anchoring vignettes. We show that, even if, ex ante, consumers fear high risk and do not associate it to a high level of happiness, their ex post evaluation of well-being is generally higher when identical consequences result from a high-risk situation than from a low-risk situation. Control over risk-taking reinforces the gap between ex ante and ex post measures of happiness. Thus, our article provides empirical evidence about a positive relation between risk and individual well-being, suggesting that risky experiences have the potential to increase consumer well-being.     

A Brief Survey of Modern Optimization for Statisticians

Modern computational statistics is turning more and more to high‐dimensional optimization to handle the deluge of big data. Once a model is formulated, its parameters can be estimated by optimization. Because model parsimony is important, models routinely include non‐differentiable penalty terms such as the lasso. This sober reality complicates minimization and maximization. Our broad survey stresses a few important principles in algorithm design. Rather than view these principles in isolation, it is more productive to mix and match them. A few well‐chosen examples illustrate this point. Algorithm derivation is also emphasized, and theory is downplayed, particularly the abstractions of the convex calculus. Thus, our survey should be useful and accessible to a broad audience.     

The Aggregate Demand Curve and Its Proper Interpretation

Textbook authors, in their presentations of aggregate demand–aggregate supply, are admonished to set their houses in order. The writers suggest the continued usefulness of the traditional “Keynesian cross” model as a pedagogical device and present a version that they allege to be superior to the popular AD–AS models found in many contemporary texts.     

Successful programs wanted: Exploring the impact of alignment

Alignment between formulation and implementation of business strategy can be important for achieving successful programs. The authors have explored the development of a program management alignment theory. Statistical testing showed that interaction between the study model variables was found to be multidimensional, complex, and subtle in influence. Thus, the authors conclude that programs have both deliberate and emergent strategies requiring design and management to be organized as complex adaptive systems. Program life‐cycle phases of design and transition were often formed from an unclear and confusing strategic picture at the outset, which can make those phases difficult to control. Learning was established as an underlying challenge. The study model demonstrated continuous alignment as an essential attribute contributing toward successful delivery. This requires program design and structure to adopt an adaptive posture.     

The Moderating Influence of Broad‐Scope Trust on Customer–Seller Relationships

Trust relates not only to customer trust in individual companies (i.e., narrow‐scope trust) but also to the broader business context in which customer–seller relationships may develop (i.e., broad‐scope trust [BST]). Based on two surveys comprising 1155 bank consumers and 817 insurance consumers, respectively, this study investigates the moderating influence of BST on relationships between satisfaction, narrow‐scope trust, and loyalty and also examines the direct influence of BST on these variables. The results indicate that whereas BST negatively moderates relationships between satisfaction and narrow‐scope trust and between narrow‐scope trust and loyalty, BST positively moderates the relationship between satisfaction and loyalty. In addition, it is demonstrated that BST positively influences customer satisfaction and narrow‐scope trust. © 2012 Wiley Periodicals, Inc.