A new parallel algorithm for parsing arithmetic infix expressions

A new parallel algorithm for transforming an arithmetic infix expression into a par se tree is presented. The technique is based on a result due to Fischer (1980) which enables the construction of the parse tree, by appropriately scanning the vector of precedence values associated with the elements of the expression. The algorithm presented here is suitable for execution on a shared memory model of an SIMD machine with no read/write conflicts permitted. It uses O(n) processors and has a time complexity of O(log²n) where n is the expression length. Parallel algorithms for generating code for an SIMD machine are also presented.     

Creep deformation behavior of Sn–Zn solder alloys

Creep properties of three Sn–Zn solder alloys (Sn–9Zn, Sn–20Zn, and Sn–25Zn, wt%) were studied using the impression creep technique. Microstructural characteristics were examined using a scanning electron microscope. The alloys exhibited stress exponents of about 5.0. The activation energy for creep was calculated to be ~50–75 kJ/mol with a mean value of 66.3 kJ/mol. The likely creep mechanism was identified to be the low temperature viscous glide of dislocations.     

Incremental recursive descent parsing

The Recursive Descent method of parsing is well established in practice. An Incremental Parsing algorithm using the Recursive Descent method is presented. The algorithm is applicable to LL(1) grammars. The algorithm has been implemented for a subset of Pascal.     

An economic production lot size model with increasing demand, shortages and partial backlogging

In this paper, an economic production quantity model is developed for a production–inventory system where the demand rate increases with time, the production rate is finite and adjustable in each cycle over an infinite planning horizon and shortages are permitted. The cost of adjusting the production rate depends linearly on the magnitude of the change in the production rate. During the stock‐out period, a known fraction of the unsatisfied demands is backordered while the remaining fraction is lost. The model is formulated taking the demand rate as a general increasing function of time and the optimal production policy is obtained for the special case of a linearly increasing demand rate. The proposed model is also shown to be suitable for a prescribed time horizon. A procedure to find approximately the minimum total cost of the system over a finite time horizon is suggested. A numerical example is taken to illustrate the solution procedure of the developed model.     

Congestion notification and probing mechanisms for endpoint admission control

There has been much interest in admission control schemes that place the burden of admission control decisions on the end users. In these schemes, referred to as Endpoint Admission Control, the decision to join the network is taken by the user, based on the probing of the network using probe packets. Depending on the level of congestion, routers mark the probe packets and thus inform the user of the state of the network. In this paper, we analyze three mechanisms for providing Endpoint Admission Control: virtual-queue marking, random-early marking and tail drop. For each scheme, we analyze the probing duration necessary to guarantee the required QoS and achieve high link utilization. Our main conclusion is that very few probe packets have to be sent when early marking is used, whereas tail drop requires a large number of probe packets.     

Technological solutions for protecting privacy

The Web is commonly viewed as an information access tool for end users. But as much as it simplifies access to stock quotes, medical libraries, or reference manuals, the Web also makes it easier for individuals and organizations to obtain and infer. Emerging technologies can protect privacy without restricting the information flow crucial to efficient organizations. Solutions to privacy concern must combine laws, societal norms, market and technology.     

Hedging policies for failure-prone manufacturing systems:optimality of JIT and bounds on buffer levels

The authors consider multiple part-type single-machine manufacturing systems subject to failures. They provide necessary and sufficient conditions for the optimality of just-in-time (JIT) manufacturing, and further show that the necessary and sufficient conditions coincide when the backlog costs for all the parts are equal. In general, finding optimal hedging policies for multiple part-type problems is extremely difficult. They provide bounds on the optimal hedging points and also prove that, under an optimal hedging policy, the buffer levels will be upper bounded     

Desaturation indices in liver, muscle, and bone of growing male and female mice fed trans-10, cis-12 conjugated linoleic acid

trans-10, cis-12-CLA (t10,c12-CLA) inhibits lipid deposition in adipose tissue of many species, but it also enhances lipid deposition in liver. We evaluated effects of dietary t10,c12-CLA content and gender on carcass composition, FA profile of selected tissues, and expression of FA synthase (FAS) and stearoyl-CoA desaturase-1 (SCD) mRNA in adipose tissue. Male and female (63 of each) CD-1 mice were assigned a diet containing 0.0, 0.15, or 0.30% t10,c12-CLA at 4 wk of age. Seven mice per dietary group within gender were sacrificed after 2,4 or 6 wk. The CLA isomer caused dose-dependent reductions in dry carcass weight and fat content, without altering protein content, but carcass fat and epididymal fat pad weights of males were reduced to a greater extent than carcass fat and inguinal fat pad weights of females. FAS and SCD mRNA in adipose tissue was more abundant in females than males, but expression in both genders decreased as the t10, c12-CLA content of the diet increased. Although the weight of gastrocnemius muscle was not influenced by diet, total FA content of the muscle of both genders decreased in response to dietary t10,c12-CLA content. Femur weight of male mice increased as the t10,c12-CLA content of the diet increased, but the weight increase was associated with a reduction in total FA content. The Δ9 desaturation indices for muscle and femur suggested a linear reduction in SCD activity, whereas Δ9 indices for liver indicated linear enhancement of SCD activity. Overall, results suggested that growing male mice were more susceptible than females to t10,c12-CLA inhibition of lipid deposition.     

Distributed Link Scheduling With Constant Overhead

This paper proposes a new class of simple, distributed algorithms for scheduling in multihop wireless networks under the primary interference model. The class is parameterized by integers k ges 1. We show that algorithm k of our class achieves k/(k + 2) of the capacity region, for every k ges 1. The algorithms have small and constant worst-case overheads. In particular, algorithm k generates a new schedule using a) time less than 4k + 2 round-trip times between neighboring nodes in the network and b) at most three control transmissions by any given node for any k. The control signals are explicitly specified and face the same interference effects as normal data transmissions. Our class of distributed wireless scheduling algorithms are the first ones guaranteed to achieve any fixed fraction of the capacity region while using small and constant overheads that do not scale with network size. The parameter k explicitly captures the tradeoff between control overhead and throughput performance and provides a tuning-knob protocol designers can use to harness this tradeoff in practice.     

RAPTAP: a socio-inspired approach to resource allocation and interference management in dense small cells

Wireless Networks - Femto Cells offer higher data rates to users within closed spaces. Dense deployment of small cells is a characteristic of pre-5G/LTE-Advanced Pro (LTE-A Pro) networks and is a...