An important challenge for modern data centers is to provide users with low-latency, high-quality, and interactive services. To improve effective application throughput, much work has been done to take into account application deadline in the design of the network flow schedule for transmission of the queried data. This raises a critical question: does application-level throughput necessarily translate to better quality of service for users? We note that queries responses typically include a set of semantically related documents (within a flow), and that while some documents are highly related to that query, others are not. This motivates us to consider the degree of a document’s semantic relatedness in the design of an efficient data transmission scheme for data centers. To understand the performance upper bound, we derive a mixed integer linear programming (MILP) model for the above problem, which can be regarded as the schedule of a network subflow problem and is hence complicated. Thus, we propose the importance-aware transmission control protocol (ITCP), a distributed event-driven rate-based delivery control protocol, for server-centric data center networks. ITCP jointly considers the subflow importance, size, and deadline, as well as the characteristics of the underlying infrastructure to maximize the goodput of the most relevant responses of a query. The results of both real and synthetic data simulations show that ITCP outperforms recent works in terms of mean average precision of top $k$ data and the sum of application-level importance.

Designing a lifetime-maximization routing in wireless sensor networks poses a great challenge mainly due to unreliable wireless links and limited power supply. Recently, two natural advantages of opportunistic routing, i.e., path diversity and the improvement of transmission reliability, are exploited to develop a lifetime-extended opportunistic routing for wireless sensor networks. Besides, asynchronous sleep-wake scheduling is an effective mechanism to reduce energy consumption by appropriately arranging sensor nodes to sleep. Hence, in this paper, we propose a joint design of asynchronous sleep-wake schedules and opportunistic routing, called ASSORT, to maximize the network lifetime. Simulation results show that ASSORT effectively achieves network lifetime extension compared with other routing schemes.

Today's datacenters face important challenges for providing low-latency high-quality interactive services to meet user's expectation. For improving the application throughput, recent research works have embedded application deadline information into design of network flow schedule to meet the latency requirement. Here, arises a critical question: does application-level throughput mean providing better quality service? We note that there are usually a set of semantic related responses (or flows) for answering a query; and, some responses are highly correlative with the query while others do not. Thus, this observation motivates us to associate the importance of the contents with the application flows (or responses) in order to enhance the service quality. We first model the application importance maximization problem in a generic network and in a server-centric network. Since both of them are too complicated to be deployed in the real world, we propose the importance-aware delivery protocol, which is a distributed event-driven rate-based delivery control protocol, for server-centric datacenter networks. The proposed protocol is able to make use of the multiple disjoin paths of server-centric network, and jointly consider flow importance, flow size, and deadline to maximize the goodput of most-related semantic data of a query. Through real-data-based or synthetic simulations, the results show that our proposed protocol significantly outperforms D3 and MPTCP in terms of the precision at K and the sum of application-level importance.

We measure the seismic moment of five great (Ms ≥ 7.8) earthquakes from 1928 to 1942 along the Mexican portion of the Middle American Trench directly from recorded seismograms, and obtain considerably lower moment values than had previously been estimated from Ms. Such direct moment determinations are inherently more reliable.As the average seismic slip rate along this portion of the arc appears to be essentially constant, these measurements of the past seismic moment are used to estimate that the current (end of 1980) moment deficiency, is 46 × 1027 dyne‐cm, or an average slip of 97 cm along the arc. Although this is much lower than past estimates, at the current rate of increase, 1.6 × 1027 dyne‐cm/yr (3.4 cm/yr of seismic displacement), the moment deficiency by 1985 will be the equivalent of five magnitude 8 earthquakes; and by 1990, six such events. The slip along this portion of the Middle America Trench arc appears to fit Shimazaki and Nakata's "slip predictable" model, in which the size, but not the time of occurrence, of future large events may be estimated.

To investigate the state of stress in marginal seas, we have studied the October 7, 1965 (mb = 5.9, Ms = 5.6), earthquake in the center of the South China Sea. This is one of the largest events in the interior of a marginal sea since the installation of the World‐Wide Standard Seismograph Network. Using body and surface wave analysis, the focal mechanism is found to be almost pure thrust faulting at a very shallow depth (about 5 km) with a seismic moment of 1×1025 dyn cm. The mechanism indicates horizontal compression oriented N38°W. Since this event does not occur on a bathymetric feature, its mechanism may indicate the overall state of stress in the South China Sea.

An active seismic zone extends along the passive margin of eastern North America from Baffin Island to the Grand Banks of Newfoundland. We have determined the focal mechanisms of several of the earthquakes, including the 1933 Ms 7.3 Baffin Bay earthquake, the largest event ever recorded along the eastern North American margin. The mechanisms show thrust faulting for earthquakes seaward of the 1000 m contour, and primarily normal faulting for earthquakes landward. We propose that these earthquakes are induced by the removal of the Pleistocene glacial loads which extended onto the continental shelf. The deglaciation reactivated basement faults remaining from rifting associated with the opening of the Labrador Sea. Baffin Bay and the Atlantic. A simple flexure calculation yields horizontal extension (normal faulting) in the previously glaciated region, and horizontal compression (thrust faulting) farther seaward, in good general agreement with the observed earthquake mechanisms. The magnitude of the stresses, 100 to 150 bars, is sufficient to reactivate preexisting basement faults. Large passive margin earthquakes may occur as far south along the coast as glaciation extended.