Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017.

BACKGROUND: Global development goals increasingly rely on country-specific estimates for benchmarking a nation's progress. To meet this need, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 estimated global, regional, national, and, for selected locations, subnational cause-specific mortality beginning in the year 1980. Here we report an update to that study, making use of newly available data and improved methods. GBD 2017 provides a comprehensive assessment of cause-specific mortality for 282 causes in 195 countries and territories from 1980 to 2017. METHODS: The causes of death database is composed of vital registration (VR), verbal autopsy (VA), registry, survey, police, and surveillance data. GBD 2017 added ten VA studies, 127 country-years of VR data, 502 cancer-registry country-years, and an additional surveillance country-year. Expansions of the GBD cause of death hierarchy resulted in 18 additional causes estimated for GBD 2017. Newly available data led to subnational estimates for five additional countries-Ethiopia, Iran, New Zealand, Norway, and Russia. Deaths assigned International Classification of Diseases (ICD) codes for non-specific, implausible, or intermediate causes of death were reassigned to underlying causes by redistribution algorithms that were incorporated into uncertainty estimation. We used statistical modelling tools developed for GBD, including the Cause of Death Ensemble model (CODEm), to generate cause fractions and cause-specific death rates for each location, year, age, and sex. Instead of using UN estimates as in previous versions, GBD 2017 independently estimated population size and fertility rate for all locations. Years of life lost (YLLs) were then calculated as the sum of each death multiplied by the standard life expectancy at each age. All rates reported here are age-standardised

Internet : history, impact, enabling technologies and potential problems

This short article gives a brief history of the development and growth of the Internet, the applications and their impact on society, the major enabling technologies, and the potential problems. It is intended to be a concise summary of the most important things to know about the Internet without getting into technical details. A general understanding of Computer Science subjects, especially on computer networks and protocols, is assumed

The minimal cost distribution tree problem for recursive expiration-based consistency management

The expiration-based scheme is widely used to manage the consistency of cached and replicated contents such as Web objects. In this approach, each replica is associated with an expiration time beyond which the replica has to be validated. While the expiration-based scheme has been investigated in the context of a single replica, not much work has been done on its behaviors with respect to multiple replicas. To allow for efficient consistency management, it is desirable to organize the replicas into a distribution tree where a lower level replica seeks validation with a higher level replica when its lifetime expires. This paper investigates the construction of a distribution tree for a given set of replicas with the objective of minimizing the total communication cost of consistency management. This is formulated as an optimization problem and is proven to be NP-complete. The optimal distribution tree is identified in some special cases and several heuristic algorithms are proposed for the general problem. The performance of the heuristic algorithms is experimentally evaluated against two classical graph-theoretic algorithms of tree construction: the shortest-paths tree and the minimum spanning tree

Processor Voltage Scheduling for Real-Time Tasks With Non-Preemptible Sections

As mobile computing is getting popular, there is an increasing interest in techniques that can minimize energy consumption and prolong the battery life on mobile devices. Processor voltage scheduling is an effective way to reduce energy dissipation by reducing the processor speed. In this paper, we study voltage scheduling for real-time periodic tasks with non-preemptible sections. Three schemes are proposed to address this problem. The static speed algorithm derives a static feasible speed based on the Stack Resource Policy (SRP). As worst-case blocking does not always occur, the novel dual speed algorithm switches the processor speed to a lower value whenever possible. The dynamic reclaiming algorithm deploys a reservation-based approach to reclaim unused run time for redistribution. It effectively decreases the processor idle time and further reduces the processor speed. The feasibility conditions are given and proved. Simulation results show that the two dynamic algorithms can reduce processor energy consumption by up to 80 percent over the static speed scheme

ATM admission models of stochastic high level petri nets based on hierarchical modeling

This paper presents a framework for modeling and analyzing ATM admission control using Stochastic High Level Petri Net (SHLPN). SHLPN is chosen because it is a powerful graphical and mathematical modeling tool that is able to handle concurrent, asynchronous, nondeterministic and stochastic events. In addition, there exists a set of well-developed performance analysis techniques for SHLPN. This paper uses a hierarchical modeling technique to specify complex ATM network mechanisms using a top-down approach. However, in analyzing the performance of the network, a bottom-up approach is adopted. To tackle the state space explosion problem, a SHLPN model is decomposed into submodels. These subnets are independently evaluated with all possible population which are then substituted by transitions with approximate equivalent performance in the original model. The technique is illustrated by modeling and evaluating a specific connection admission control policy