Efficient Algorithms for Cache-Throughput Analysis in Cellular-D2D 5G Networks

In this paper, we propose a two-tiered segment-based Device-to-Device (S-D2D) caching approach to decrease the startup and playback delay experienced by Video-on-Demand (VoD) users in a cellular network. In the S-D2D caching approach cache space of each mobile device is divided into two cache-blocks. The first cache-block reserve for caching and delivering the beginning portion of the most popular video files and the second cache-block caches the latter portion of the requested video files ‘fully or partially’ depending on the users’ video watching behaviour and popularity of videos. In this approach before caching, video is divided and grouped in a sequence of fixed-sized fragments called segments. To control the admission to both cache-blocks and improve the system throughput, we further propose and evaluate three cache admission control algorithms. We also propose a video segment access protocol to elaborate on how to cache and share the video segments in a segmentation based D2D caching architecture. We formulate an optimisation problem and find the optimal cache probability and beginning-segment size that maximise the cache-throughput probability of beginning-segments. To solve the non-convex cache-throughout maximisation problem, we derive an iterative algorithm, where the optimal solution is derived in each step. We used extensive simulations to evaluate the performance of our proposed S-D2D caching system.     

The pseudorandom sequence of arrays

Pseudorandom (or maximal length) sequences and arrays have been known for a long time, and have been reported by several authors. Pseudorandom volumes have also been mentioned.This paper presents a different type of sequence of arrays in which the arrays share many properties with the pseudorandom arrays of the literature, and the sequence (or group) of arrays has many properties in common with the pseudorandom sequences. It is proposed that this set of arrays be called a pseudorandom sequence of arrays, or PRSAs. Some interesting properties of the PRSA as well as its practical (hardware) implementation have been mentioned. It has also been shown that our result is a special case of the generalN(3)/D(3) case.     

Airflow analysis in an air conditioning room

The aim of superior air conditioning system is no longer constrained to advancing the efficiency of cooling machine, but includes the study of airflow with the assistance of the distribution of several significant parameters. A simple numerical study of the turbulent flow over an enclosed air conditioning system was not practicable a few decades ago since the computer facilities were not sufficient. In this paper, a standard office room was taken up for simulation. Temperature and velocity distribution over various virtual planes for different locations of the air conditioner blower were analyzed to achieve the maximum comfort for the occupant. With Fluent, as solution tool, k–epsilon and Reynolds stress models for turbulence flow were used for the analysis. The different locations of blower placement are analyzed for better comfort of occupant in the room and it is found that the occupant will experience most comfort if the air conditioner blower is placed on location II compared to the other two locations. This work can also be extended to a more complex air conditioning system like in the industries, hospitals as well as the gigantic shopping malls.     

Hierarchical congregated ant system for bottom-up VLSI placements

A new perturbation method, called Hierarchical-Congregated Ant System (H-CAS) has been proposed to perform the variable-order bottom-up placement for VLSI. H-CAS exploits the concept of ant colonies, where each ant will generate the perturbation based on differences in dimensions of the VLSI modules in hard modules floorplanning and differences in area of the VLSI modules in soft modules floorplanning. In this paper, it is mathematically proved that the area-based two-dimensional cost function for hard modules floorplanning problem can be reduced to the difference-based one dimensional cost function which avoids local optima problems. Lack of global view is a major drawback in the conventional bottom-up hierarchy, and hence, ants in the H-CAS are made to introduce global information at every level of bottom-up hierarchy. A new relative whitespace formula for bottom-up hierarchy is derived mathematically and the H-CAS embeds it in its unique update formula. The ants in H-CAS are able to communicate among themselves and update the pheromone trails when they reach the destination. Then, the ants will congregate, share their experiences and construct a new pheromone trails that belong to this newly constructed group. The congregation of at least two ants and/or ant consortiums would lead to reduction in subsequent search space and complexity. H-CAS gives the best-so-far near optimal solutions and yields low standard deviations of areas involving 9–600 blocks based on Microelectronics Center of North Carolina (MCNC) and Giga scale Systems Research Center (GSRC) benchmarks. The results obtained establish that H-CAS is a high performance placer in respect of scaling, convergence, precision, stability, and reliability. The above claims are based on the comparisons with the other floorplanning algorithms as depicted graphically.     

Activating MoS2 Basal Plane with Ni2P Nanoparticles for Pt‐Like Hydrogen Evolution Reaction in Acidic Media

2D molybdenum disulfide (MoS₂) displays a modest hydrogen evolution reaction (HER) activity in acidic media because the active sites are limited to a small number of edge sites with broader basal planes remaining mostly inert. Here, it is reported that the MoS₂ basal planes could be activated by growing nickel phosphide (Ni₂P) nanoparticles on them. Thus a Ni₂P/MoS₂ heterostructure is constructed via in situ phosphidation of an indigenously synthesized NiMoS₄ salt as a single precursor to form a widely cross‐doped and chemically connected heterostructure. The conductivity and stability of the Ni₂P/MoS₂ heterostructure are further enhanced by hybridization with conductive N‐doped carbon supports. As a result, the Ni₂P/MoS₂/N:RGO or Ni₂P/MoS₂/N:CNT electrocatalyst displays Pt‐like HER performance in acidic media, outperforming the incumbent best HER electrocatalyst, Pt/C, in a more meaningful high current density region (>200 mA cm^?2) making them a promising candidate for practical water electrolysis applications. Since nonprecious metal catalysts showing Pt‐like HER performance in acidic media are rare, the Ni₂P/MoS₂ heterostructure catalyst is a promising candidate for practical hydrogen production via water electrolysis.     

An efficient approach for publishing microdata for multiple sensitive attributes

The publication of microdata is pivotal for medical research purposes, data analysis and data mining. These published data contain a substantial amount of sensitive information, for example, a hospital may publish many sensitive attributes such as diseases, treatments and symptoms. The release of multiple sensitive attributes is not desirable because it puts the privacy of individuals at risk. The main vulnerability of such approach while releasing data is that if an adversary is successful in identifying a single sensitive attribute, then other sensitive attributes can be identified by co-relation. A whole variety of techniques such as SLOMS, SLAMSA and others already exist for the anonymization of multiple sensitive attributes; however, these techniques have their drawbacks when it comes to preserving privacy and ensuring data utility. The extant framework lacks in terms of preserving privacy for multiple sensitive attributes and ensuring data utility. We propose an efficient approach (p, k)-Angelization for the anonymization of multiple sensitive attributes. Our proposed approach protects the privacy of the individuals and yields promising results compared with currently used techniques in terms of utility. The (p, k)-Angelization approach not only preserves the privacy by eliminating the threat of background join and non-membership attacks but also reduces the information loss thus improving the utility of the released information.     

High performance thermoplastic composites: Study on the mechanical,thermal, and electrical resistivity properties of carbon fiber‐reinforced polyetheretherketone and polyethersulphone

High temperature processing thermoplastic polymers, polyetheretherketone (PEEK) and polyethersulphone (PES), were melt blended with carbon fibers (CFs) to make composites. These composites were investigated for their mechanical, thermal, and electrical properties. Mechanical properties that are expressed in terms of storage modulus, loss, and damping were enhanced with the addition of CFs. Thermal properties were determined by DSC and TGA. These methods help to understand the effects of fiber content and fiber–matrix adhesion in the composites. Composites were also tested for their electrical and thermal conductivity because CFs leave the composites thermally and electrically conductive. CFs enhanced the crystallinity of the PEEK appreciably that in turn influenced thermal conductivity, electrical resistivity, and the stiffness of PEEK/CF (composites of PEEK with CFs). PES/CF (composites of PES with CF) shows a different behavior due to the amorphous nature of PES. The work involves one filler and two different matrices, and so it provides an interesting comparison of how matrix morphology can influence the properties of composites. POLYM. COMPOS. 28:785–796, 2007. © 2007 Society of Plastics Engineers.     

An adaptive key selection method for the multilevel index model for effective service management in the cloud

The growing number of services processed and stored in the cloud has led to difficulties in managing and discovering the required services efficiently. Multilevel index model is an efficient method to manage and retrieve services in service repositories. When adding a new service to a multilevel index model, a key needs to be selected for the service, but existing key selection methods cannot adapt to the situation that hot services change over time. To address this problem, this article proposes an adaptive key selection method to improve the efficiency of service retrieval. However, the service addition operation of the adaptive key selection method is inefficient in the multilevel index model. For this reason, this article improves the multilevel index model by introducing local equivalence partition. This indexing model improves the service addition efficiency of the adaptive key selection method without affecting the service retrieval efficiency. It is experimentally demonstrated that the retrieval and addition efficiencies of the adaptive key selection method are close to the ideal state optimum under the multilevel index model with local equivalence partitioning.     

NoC映射问题中的列举路径分配算法

映射和路径分配是片上网络在编译过程中两个相辅相成的重要步骤,对系统的通信功耗影响很大。该文针对片上网络映射过程中现有路径分配法寻径不充分的问题,提出了一种基于列举的路径分配算法。该算法通过列举各通信流的所有合法路径,对路径的各种组合方式进行充分搜索。同时将路径分配算法应用到禁忌搜索映射算法中,并对映射算法做了改进,以适应路径分配算法。仿真结果表明,基于列举的路径分配算法提高了满足约束的路径被搜索到的概率,优化了映射算法的结果。     

Micronutrient fortification of wheat flour: Recent development and strategies

Deficiencies of iron, zinc and vitamin A have been a focus of the governments and world organizations for decades and extensive efforts are being made to address this malnutrition. Being a popular and most common dietary staple of the population living in sub-continent and developing countries, wheat flour (WF) has gained a significant attention as a suitable vehicle for micronutrient fortification. Fortification of wheat flour has been established as an appropriate strategy to curtail micronutrient deficiencies especially in the developing economies. Extent of the prevalence of micronutrient deficiencies, their consequences, selection of a suitable vehicle, choice of fortificants and their levels and storage stability, acceptability and bioavailability of iron and zinc fortified WF are the key points of discussion in the current review. This review further highlights multifaceted issues pertaining to the appropriateness and suitability of fortification over other intervention strategies, ecological needs and fortification success stories and advantages of simply adding fortificants to flour to meet nutritional requirements of vulnerable groups. The authors have attempted to encompass the subject matter based on their research endeavors made in this direction.