OpenRaiser/Intern-Atlas huggingface dataset:
Interference Alignment with Partial CSI Feedback in MIMO Cellular Networks
Venue: arXiv cs.IT 2014
Year: 2014

Interference alignment (IA) is a linear precoding strategy that can achieve optimal capacity scaling at high SNR in interference networks. However, most existing IA designs require full channel state information (CSI) at the transmitters, which would lead to significant CSI signaling overhead. There are two techniques, namely CSI quantization and CSI feedback filtering, to reduce the CSI feedback overhead. In this paper, we consider IA processing with CSI feedback filtering in MIMO cellular networks. We introduce a novel metric, namely the feedback dimension, to quantify the first order CSI feedback cost associated with the CSI feedback filtering. The CSI feedback filtering poses several important challenges in IA processing. First, there is a hidden partial CSI knowledge constraint in IA precoder design which cannot be handled using conventional IA design methodology. Furthermore, existing results on the feasibility conditions of IA cannot be applied due to the partial CSI knowledge. Finally, it is very challenging to find out how much CSI feedback is actually needed to support IA processing. We shall address the above challenges and propose a new IA feasibility condition under partial CSIT knowledge in MIMO cellular networks. Based on this, we consider the CSI feedback profile design subject to the degrees of freedom requirements, and we derive closed-form trade-off results between the CSI feedback cost and IA performance in MIMO cellular networks.
Parallel Interleaver Design for a High Throughput HSPA+/LTE Multi-Standard Turbo Decoder
Venue: arXiv cs.IT 2014
Year: 2014

To meet the evolving data rate requirements of emerging wireless communication technologies, many parallel architectures have been proposed to implement high throughput turbo decoders. However, concurrent memory reading/writing in parallel turbo decoding architectures leads to severe memory conflict problem, which has become a major bottleneck for high throughput turbo decoders. In this paper, we propose a flexible and efficient VLSI architecture to solve the memory conflict problem for highly parallel turbo decoders targeting multi-standard 3G/4G wireless communication systems. To demonstrate the effectiveness of the proposed parallel interleaver architecture, we implemented an HSPA+/LTE/LTE-Advanced multi-standard turbo decoder with a 45nm CMOS technology. The implemented turbo decoder consists of 16 Radix-4 MAP decoder cores, and the chip core area is 2.43 mm^2. When clocked at 600 MHz, this turbo decoder can achieve a maximum decoding throughput of 826 Mbps in the HSPA+ mode and 1.67 Gbps in the LTE/LTE-Advanced mode, exceeding the peak data rate requirements for both standards.
Geographic routing protocols for underwater wireless sensor networks:a survey
Venue: arXiv cs.NI 2014
Year: 2014

Underwater wireless sensor networks (UWSN), similar to the terrestrial sensor networks, have different challenges such as limited bandwidth, low battery power, defective underwater channels, and high variable propagation delay. A crucial problem in UWSN is finding an efficient route between a source and a destination. Consequently, great efforts have been made for designing efficient protocols while considering the unique characteristics of underwater communication. Several routing protocols are proposed for this issue and can be classified into geographic and non-geographic routing protocols. In this paper we focus on the geographic routing protocols. We introduce a review and comparison of different algorithms proposed recently in the literature. We also presented a novel taxonomy of these routing in which the protocols are classified into three categories (greedy, restricted directional flooding and hierarchical) according to their forwarding strategies.
Think Locally, Act Locally: The Detection of Small, Medium-Sized, and Large Communities in Large Networks
Venue: arXiv cs.SI 2014
Year: 2014

It is common in the study of networks to investigate meso-scale features to try to gain an understanding of network structure and function. For example, numerous algorithms have been developed to try to identify "communities," which are typically construed as sets of nodes with denser connections internally than with the remainder of a network. In this paper, we adopt a complementary perspective that "communities" are associated with bottlenecks of locally-biased dynamical processes that begin at seed sets of nodes, and we employ several different community-identification procedures (using diffusion-based and geodesic-based dynamics) to investigate community quality as a function of community size. Using several empirical and synthetic networks, we identify several distinct scenarios for ``size-resolved community structure'' that can arise in real (and realistic) networks. Depending on which scenario holds, one may or may not be able to successfully identify ``good'' communities in a given network, the manner in which different small communities fit together to form meso-scale network structures can be very different, and processes such as viral propagation and information diffusion can exhibit very different dynamics.In addition, our results suggest that, for many large realistic networks, the output of locally-biased methods that focus on communities that are centered around a given seed node might have better conceptual grounding and greater practical utility than the output of global community-detection methods. They also illustrate subtler structural properties that are important to consider in the development of better benchmark networks to test methods for community detection. [Note: Because of space limitations in the arXiv's abstract field, this is an abridged version of the paper's abstract.]
Towards slime mould electrical logic gates with optical coupling
Venue: arXiv cs.ET 2014
Year: 2014

Physarum polycephalum is a macroscopic single celled plasmodial slime mould. We employ plasmodial phototactic responses to construct laboratory prototypes of NOT and NAND logical gates with electrical inputs/outputs and optical coupling; the slime mould plays dual roles of computing device and electrical conductor. Slime mould logical gates are fault tolerant and resettable. The results presented here advance our understanding of how biological computing substrates may be manipulated to implement logical operations and demonstrate the feasibility of integrating living substrates into silicon hardware.
Whose Opinion to follow in Multihypothesis Social Learning? A Large Deviations Perspective
Venue: arXiv cs.IT 2014
Year: 2014

We consider a multihypothesis social learning problem in which an agent has access to a set of private observations and chooses an opinion from a set of experts to incorporate into its final decision. To model individual biases, we allow the agent and experts to have general loss functions and possibly different decision spaces. We characterize the loss exponents of both the agent and experts, and provide an asymptotically optimal method for the agent to choose the best expert to follow. We show that up to asymptotic equivalence, the worst loss exponent for the agent is achieved when it adopts the 0-1 loss function, which assigns a loss of 0 if the true hypothesis is declared and a loss of 1 otherwise. We introduce the concept of hypothesis-loss neutrality, and show that if the agent adopts a particular policy that is hypothesis-loss neutral, then it ignores all experts whose decision spaces are smaller than its own. On the other hand, if experts have the same decision space as the agent, then choosing an expert with the same loss function as itself is not necessarily optimal for the agent, which is somewhat counter-intuitive. We derive sufficient conditions for when it is optimal for the agent with 0-1 loss function to choose an expert with the same loss function.
Simulation leagues: Analysis of competition formats
Venue: arXiv cs.MA 2014
Year: 2014

The selection of an appropriate competition format is critical for both the success and credibility of any competition, both real and simulated. In this paper, the automated parallelism offered by the RoboCupSoccer 2D simulation league is leveraged to conduct a 28,000 game round-robin between the top 8 teams from RoboCup 2012 and 2013. A proposed new competition format is found to reduce variation from the resultant statistically significant team performance rankings by 75% and 67%, when compared to the actual competition results from RoboCup 2012 and 2013 respectively. These results are statistically validated by generating 10,000 random tournaments for each of the three considered formats and comparing the respective distributions of ranking discrepancy.
A Short Note on Zero-error Computation for Algebraic Numbers by IPSLQ
Venue: arXiv cs.SC 2014
Year: 2014

The PSLQ algorithm is one of the most popular algorithm for finding nontrivial integer relations for several real numbers. In the present work, we present an incremental version of PSLQ. For some applications needing to call PSLQ many times, such as finding the minimal polynomial of an algebraic number without knowing the degree, the incremental PSLQ algorithm is more efficient than PSLQ, both theoretically and practically.
Goal-oriented Data Visualization with Software Project Control Centers
Venue: arXiv cs.SE 2014
Year: 2014

Many software development organizations still lack support for obtaining intellectual control over their software development processes and for determining the performance of their processes and the quality of the produced products. Systematic support for detecting and reacting to critical project states in order to achieve planned goals is usually missing. One means to institutionalize measurement on the basis of explicit models is the development and establishment of a so-called Software Project Control Center (SPCC) for systematic quality assurance and management support. An SPCC is comparable to a control room, which is a well known term in the mechanical production domain. Its tasks include collecting, in- terpreting, and visualizing measurement data in order to provide context-, purpose-, and role-oriented information for all stakeholders (e.g., project managers, quality assurance manager, developers) during the execution of a software development project. The article will present an overview of SPCC concepts, a concrete instantiation that supports goal-oriented data visualization (G-SPCC approach), and experiences from practical applications.
Polynomial Complexity Minimum-Time Scheduling in a Class of Wireless Networks
Venue: arXiv cs.NI 2014
Year: 2014

We consider a wireless network with a set of transmitter-receiver pairs, or links, that share a common channel, and address the problem of emptying finite traffic volume from the transmitters in minimum time. This, so called, minimum-time scheduling problem has been proved to be NP-hard in general. In this paper, we study a class of minimum-time scheduling problems in which the link rates have a particular structure consistent with the assumed environment and topology. We show that global optimality can be reached in polynomial time and derive optimality conditions. Then we consider a more general case in which we apply the same approach and thus obtain approximation as well as lower and upper bounds to the optimal solution. Simulation results confirm and validate our approach.
A Receding Horizon Approach to Multi-Agent Planning from Local LTL Specifications
Venue: arXiv cs.RO 2014
Year: 2014

We study the problem of control synthesis for multi-agent systems, to achieve complex, high-level, long-term goals that are assigned to each agent individually. As the agents might not be capable of satisfying their respective goals by themselves, requests for other agents' collaborations are a part of the task descriptions. Particularly, we consider that the task specification takes a form of a linear temporal logic formula, which may contain requirements and constraints on the other agent's behavior. A traditional automata-based approach to multi-agent strategy synthesis from such specifications builds on centralized planning for the whole team and thus suffers from extreme computational demands. In this work, we aim at reducing the computational complexity by decomposing the strategy synthesis problem into short horizon planning problems that are solved iteratively, upon the run of the agents. We discuss the correctness of the solution and find assumptions, under which the proposed iterative algorithm leads to provable eventual satisfaction of the desired specifications.
Semantic information and artificial intelligence
Venue: arXiv cs.LO 2014
Year: 2014

For a computational system to be intelligent, it should be able to perform, at least, basic deductions. Nonetheless, since deductions are, in some sense, equivalent to tautologies, it seems that they do not provide new information. The present article proposes a measure the degree of semantic informativity of valid deductions in a dynamic setting. Concepts of coherency and relevancy, displayed in terms of insertions and deletions on databases, are used to define semantic informativity. In this way, the article shows that a solution to the problem about the informativity of deductions provides a heuristic principle to improve the deductive power of computational systems.
Increasing Flash Memory Lifetime by Dynamic Voltage Allocation for Constant Mutual Information
Venue: arXiv cs.IT 2014
Year: 2014

The read channel in Flash memory systems degrades over time because the Fowler-Nordheim tunneling used to apply charge to the floating gate eventually compromises the integrity of the cell because of tunnel oxide degradation. While degradation is commonly measured in the number of program/erase cycles experienced by a cell, the degradation is proportional to the number of electrons forced into the floating gate and later released by the erasing process. By managing the amount of charge written to the floating gate to maintain a constant read-channel mutual information, Flash lifetime can be extended. This paper proposes an overall system approach based on information theory to extend the lifetime of a flash memory device. Using the instantaneous storage capacity of a noisy flash memory channel, our approach allocates the read voltage of flash cell dynamically as it wears out gradually over time. A practical estimation of the instantaneous capacity is also proposed based on soft information via multiple reads of the memory cells.
The Homogeneous Weight Partition and its Character-Theoretic Dual
Venue: arXiv cs.IT 2014
Year: 2014

The values of the normalized homogeneous weight are determined for arbitrary finite Frobenius rings and expressed in a form that is independent from a generating character and the Möbius function on the ring. The weight naturally induces a partition of the ring, which is invariant under left or right multiplication by units. It is shown that the character-theoretic left-sided dual of this partition coincides with the right-sided dual, and even more, the left- and right-sided Krawtchouk coefficients coincide. An example is provided showing that this is not the case for general invariant partitions if the ring is not semisimple.
SNSAPI: A Cross-Platform Middleware for Rapid Deployment of Decentralized Social Networks
Venue: arXiv cs.SI 2014
Year: 2014

In this paper, we present the design, implementation and our year-long maintenance experience of SNSAPI, a Python-based middleware which unifies the interfaces and data structures of heterogeneous Social Networking Services (SNS). Unlike most prior works, our middleware is user-oriented and requires zero infrastructure support. It enables a user to readily conduct online social activities in a programmable, cross-platform fashion while gradually reducing the dependence on centralized Online Social Networks (OSN). More importantly, as the SNSAPI middleware can be used to support decentralized social networking services via conventional communication channels such as RSS or Email, it enables the deployment of Decentralized Social Networks (DSN) in an incremental, ad hoc manner. To demonstrate the viability of such type of DSNs, we have deployed an experimental 6000-node SNSAPI-based DSN on PlanetLab and evaluate its performance by replaying traces of online social activities collected from a mainstream OSN. Our results show that, with only mild resource consumption, the SNSAPI-based DSN can achieve acceptable forwarding latency comparable to that of a centralized OSN. We also develop an analytical model to characterize the trade-offs between resource consumption and message forwarding delay in our DSN. Via 20 parameterized experiments on PlanetLab, we have found that the empirical measurement results match reasonably with the performance predicted by our analytical model.
Joint Beamforming Design and Time Allocation for Wireless Powered Communication Networks
Venue: arXiv cs.IT 2014
Year: 2014

This paper investigates a multi-input single-output (MISO) wireless powered communication network (WPCN) under the protocol of harvest-then-transmit. The power station (PS) with reliable power supply can replenish the passive user nodes by wireless power transfer (WPT) in the downlink (DL), then each user node transmits independent information to the sink by a time division multiple access (TDMA) scheme in the uplink (UL). We consider the joint time allocation and beamforming design to maximize the system sum-throughput. The semidefinite relaxation (SDR) technique is applied to solve the nonconvex design problem. The tightness of SDR approximation, thus the global optimality, is proved. This implies that only one single energy beamformer is required at the PS. Then a fast semiclosed form solution is proposed by exploiting the inherent structure. Simulation results demonstrate the efficiency of the proposed algorithms from the perspectives of time complexity and information throughput.
A Flexible Design for Optimization of Hardware Architecture in Distributed Arithmetic based FIR Filters
Venue: arXiv cs.AR 2014
Year: 2014

FIR filters are used in many performance/power critical applications such as mobile communication devices, analogue to digital converters and digital signal processing applications. Design of appropriate FIR filters usually causes the order of filter to be increased. Synthesis and tape-out of high-order FIR filters with reasonable delay, area and power has become an important challenge for hardware designers. In many cases the complexity of high-order filters causes the constraints of the total design could not be satisfied. In this paper, efficient hardware architecture is proposed for distributed arithmetic (DA) based FIR filters. The architecture is based on optimized combination of Look-up Tables (LUTs) and compressors. The optimized system level solution is obtained from a set of dynamic programming optimization algorithms. The experiments show the proposed design educed the delay cost between 16%-62.5% in comparison of previous optimized structures for DA-based architectures.
Quantized Feedback Stabilization of Sampled-Data Switched Linear Systems
Venue: arXiv cs.SY 2014
Year: 2014

We propose a stability analysis method for sampled-data switched linear systems with quantization. The available information to the controller is limited: the quantized state and switching signal at each sampling time. Switching between sampling times can produce the mismatch of the modes between the plant and the controller. Moreover, the coarseness of quantization makes the trajectory wander around, not approach, the origin. Hence the trajectory may leave the desired neighborhood if the mismatch leads to instability of the closed-loop system. For the stability of the switched systems, we develop a sufficient condition characterized by the total mismatch time. The relationship between the mismatch time and the dwell time of the switching signal is also discussed.
Load flow analysis of radial distribution network using linear data structure
Venue: arXiv cs.OH 2014
Year: 2014

Distribution systems hold a very significant position in the power system since it is the main point of link between bulk power and consumers. A planned and effective distribution network is the key to cope up with the ever increasing demand for domestic, industrial and commercial load. The load-flow study of radial distribution network is of prime importance for effective planning of load transfers. Power companies are interested in finding the most efficient configuration for minimization of real power loses and load balancing among distribution feeders to save energy and enhance the over all performance of distribution system. This thesis presents a fast and efficient method for load-flow analysis of radial distribution networks. The proposed method is based on linear data structure. The order of time and space complexity is reported here. There is significant saving in no. of steps execution. Using graph theory concept and exploiting multi-cores architecture, the proposed method for load flow can be further investigated for obtaining more optimized solutions.
Mouse Control using a Web Camera based on Colour Detection
Venue: arXiv cs.HC 2014
Year: 2014

In this paper we present an approach for Human computer Interaction (HCI), where we have tried to control the mouse cursor movement and click events of the mouse using hand gestures. Hand gestures were acquired using a camera based on colour detection technique. This method mainly focuses on the use of a Web Camera to develop a virtual human computer interaction device in a cost effective manner.
A fast directional boundary element method for high frequency acoustic problems in three dimensions
Venue: arXiv cs.NA 2014
Year: 2014

A highly efficient fast boundary element method (BEM) for solving large-scale engineering acoustic problems in a broad frequency range is developed and implemented. The acoustic problems are modeled by the Burton-Miller boundary integral equation (BIE), thus the fictitious frequency issue is completely avoided. The BIE is discretized by using the collocation method with piecewise constant elements. The linear systems are solved iteratively and accelerated by using a newly developed kernel-independent wideband fast directional algorithm (FDA) for fast summation of oscillatory kernels. In addition, the computational efficiency of the FDA is further promoted by exploiting the low-rank features of the translation matrices. The high accuracy and nearly linear computational complexity of the present method are clearly demonstrated by typical examples. An acoustic scattering problem with dimensionless wave number $kD$ (where $k$ is the wave number and $D$ is the typical length of the obstacle) up to 1000 and the degrees of freedom up to 4 million is successfully solved within 4 hours on a computer with one core and the memory usage is 24.7 GB.
Spelling Error Trends and Patterns in Sindhi
Venue: arXiv cs.CL 2014
Year: 2014

Statistical error Correction technique is the most accurate and widely used approach today, but for a language like Sindhi which is a low resourced language the trained corpora's are not available, so the statistical techniques are not possible at all. Instead a useful alternative would be to exploit various spelling error trends in Sindhi by using a Rule based approach. For designing such technique an essential prerequisite would be to study the various error patterns in a language. This pa per presents various studies of spelling error trends and their types in Sindhi Language. The research shows that the error trends common to all languages are also encountered in Sindhi but their do exist some error patters that are catered specifically to a Sindhi language.