nils-herrmann/clean_scirepeval huggingface dataset:
Adaptive QoS for mobile multimedia applications using power control and smart antennas

There has been an increase in demand for multimedia services in wireless communication networks. The increase in data transmission required for multimedia places considerable strain on the limited resources that have traditionally served users with only speech requirements. We address the problem of providing the individual quality of service (QoS) needs of each user, according to the different multimedia service type, be it voice, video, image or data. We propose a scheme to improve the signal to interference noise ratio (SINR) for those users with multimedia services by exploiting power control and smart antennas, while not affecting users with voice service. We also propose a scheme for fast activation of new users into such a network.
Information Forensics: An Overview of the First Decade

In recent decades, we have witnessed the evolution of information technologies from the development of VLSI technologies, to communication and networking infrastructure, to the standardization of multimedia compression and coding schemes, to effective multimedia content search and retrieval. As a result, multimedia devices and digital content have become ubiquitous. This path of technological evolution has naturally led to a critical issue that must be addressed next, namely, to ensure that content, devices, and intellectual property are being used by authorized users for legitimate purposes, and to be able to forensically prove with high confidence when otherwise. When security is compromised, intellectual rights are violated, or authenticity is forged, forensic methodologies and tools are employed to reconstruct what has happened to digital content in order to answer who has done what, when, where, and how. The goal of this paper is to provide an overview on what has been done over the last decade in the new and emerging field of information forensics regarding theories, methodologies, state-of-the-art techniques, major applications, and to provide an outlook of the future.
Waveform Design for Sum Rate Optimization in Time-Reversal Multiuser Downlink Systems

Utilizing channel reciprocity, the traditional time- reversal technique boosts the signal-to-noise ratio at the receiver with very low transmitter complexity. However, the large delay spread gives rise to severe inter-symbol interference (ISI) when the data rate is high, and the performance is further degraded in the multiuser downlink due to the inter-user interference (IUI). In this work, we study the weighted sum rate optimization problem in the time-reversal multiuser downlink using waveform design. By exploiting the relation between the allocated power and the SINR targets, an iterative algorithm is proposed to optimize the waveform design through a new power allocation algorithm. Simulation results are shown to demonstrate the superior performance of the proposed algorithm in comparison with other traditional methods.
Optimal unified architectures for the real-time computation of time-recursive discrete sinusoidal transforms

An optimal unified architecture that can efficiently compute the discrete cosine, sine, Hartley, Fourier, lapped orthogonal, and complex lapped transforms for a continuous stream of input data that arise in signal/image communications is proposed. This structure uses only half as many multipliers as the previous best known scheme (Liu and Chiu, 1993). The proposed architecture is regular, modular, and has only local interconnections in both data and control paths. There is no limitation on the transform size N and only 2N-2 multipliers are needed for the DCT. The throughput of this scheme is one input sample per clock cycle. The authors provide a theoretical justification by showing that any discrete transform whose basis functions satisfy the fundamental recurrence formula has a second-order autoregressive structure in its filter realization. They also demonstrate that dual generation transform pairs share the same autoregressive structure. They extend these time-recursive concepts to multi-dimensional transforms. The resulting d-dimensional structures are fully-pipelined and consist of only d 1D transform arrays and shift registers.
Space-time diversity for multimedia delivery over wireless channels

A source-channel matched layered space-time diversity technique is presented for reliable delivery of layer coded multimedia data through wireless channels. The transmission system is transformed to multiple subchannels and each associated with different diversity gain, therefore different error performance. Similarly to the parallel transmission proposed for ADSL, we develop a parallel transmission scheme to match the source layers to the channel layers. Power control alters the error performance of each channel layer to achieve the optimal performance.
Understanding Microeconomic Behaviors in Social Networking: An engineering view

In this article, we use game theory to analyze and model human behaviors in a social network to achieve better system design. Such analysis and modeling is very general and can be applied to many social networks. From the discussion in this article, we can see that different game models should be used for different social networks with different types of interdependency. When designing a system, not only the system efficiency but also the fairness among users should be taken into account. Moreover, since users are rational and thus naturally selfish, they tend to overclaim what they may need and will not truly report their private information if cheating can improve their payoffs. Therefore, one should consider users' selfish nature and develop cheat-proof strategies to guarantee satisfactory system performance.
Full-diversity space-frequency codes for mimo-ofdm systems

This paper addresses the problem of space-frequency code design for broadband multi- antenna OFDM systems. We show that space-time codes achieving full diversity in quasi-static flat fading environment can be used to construct space-frequency codes that achieve the maximum diversity available in frequency selective MIMO fading channels. Thus, the abundant classes of existing space-time block and trel- lis codes can be used for full diversity transmission in MIMO-OFDM systems. In order to take advantages of both the MIMO systems and the OFDM, space-jrquency (SF) coded MIMO-OFDM systems were introduced in (l), and later works (2), (3) also de- scribed such systems. The performance criteria for SF coded MIMO-OFDM systems were derived in (4) and (6). In (4), the authors showed that, in general, existing ST codes cannot ex- ploit the diversity available in frequency selective MIMO chan- nels, and it was suggested that a completely new code design procedure will have to be developed for MIMO-OFDM sys- tems. Later in 151, they proposed a class of SF codes achieving full diversity with the assumption that all of the path delays are located exactly at the sampling instances. We consider a SF coded MIMO-OFDM system with Mt transmit antennas, M, receive antennas and N subcarriers. Suppose that the frequency-selective fading channels have L independent delay paths and the same power delay profile. The MIMO channel is assumed to be spatially uncorrelated and constant over each OFDM block period. The channel impulse response from transmit antenna i to receive antenna j can be modeled as hg,j(~) = ai,j(l)S(~ - T,), where 71 is the delay and ai,j(l) is the complex amplitude of the 1-th path between transmit antenna i and receive antenna j. The ai,j(l)'s are modeled as zero-mean complex Gaussian random variables with variances Elaj,j(l)12 = S;, and E,=, 6, = 1. Thus, we consider arbitrary power delay profiles. Each SF codeword is an N x Mt matrix C = {ci(n)}o~n~N-l,) ~iCM,, where ~(n) denotes the channel symbol transmitted over the n-th subcarrier by transmit an- tenna i. The OFDM transmitter applies an N-point IFFT to each column of the matrix C. After appending the cyclic prefix, the OFDM symbol corresponding to the i-th (i = 1,2, . . . , Mt) column of C is transmitted by transmit antenna i. At the receiver, after applying FFT, the received signal at the n-th subcarrier at receive antenna j is given by L-I
Block Size Forensic Analysis in Digital Images

In non-intrusive forensic analysis, we wish to find information and properties about a piece of data without any reference to the original data prior to processing. An important first step to forensic analysis is the detection and estimation of block processing. Most existing work in block measurement uses strong assumptions on the data related to the block size or the method of compression. In this paper, we propose a new method to estimate the block size in digital images in a blind manner for use in a forensic context. We make no assumptions on the block size or the nature of any previous processing. Our scheme can accurately estimate block sizes in images up to a PSNR of 42 dB where block artifacts are perceptually invisible. We also offer a measure of detection accuracy which correctly classifies an image as block-processed with a probability of 95.0% while keeping the probability of false alarm at 7.4%.
An efficient key management scheme for secure wireless multicast

In the future, many multicast services will take place in the wireless domain. However, before these services can successfully be deployed, security infrastructures must be developed that manage the keys needed to provide access control to content. We present a method for designing multicast key management trees that are suitable for mobile wireless environments. By matching the key management tree to the cellular network topology, the total communication burden is reduced by 33%-45% compared to using the traditional key management trees that are independent of the topology.
Forensics vs. anti-forensics: A decision and game theoretic framework

In order to combat the spread of digital forgeries, researchers have developed a variety of forensic techniques to verify the authenticity of digital multimedia files. Though many of these techniques can reliably detect traditional forgeries, recent research has shown that they can easily be fooled by anti-forensic operations designed to hide evidence of forgery. In response, new forensic techniques have been developed to detect the use of anti-forensics. In light of this, there is now a need to develop a theoretical understanding of the interactions between a forger using anti-forensics and a forensic investigator. In this paper, we propose techniques to evaluate the performance of anti-forensic algorithms along with a game theoretic framework for analyzing the interplay between forensics and anti-forensics. Furthermore, we propose a new automatic video frame deletion detection technique along with a technique to detect the use of video anti-forensics. We evaluate these techniques using our proposed analytical framework.
Adaptive Blind Source Separation and Equalization for Multiple-Input/Multiple-Output Systems

In this paper, we investigate adaptive blind source separation and equalization for multiple-input/multiple-output (MIMO) systems. We first analyze the convergence of the constant modulus algorithm (CMA) used in MIMO systems (MIMO-CMA). Our analysis reveals that the MIMO-CMA equalizer is able to recover one of the input signals, remove the intersymbol interference (ISI), and suppress the other input signals. Furthermore, for the MIMO finite impulse response (FIR) systems satisfying certain conditions, the MIMO-CMA FIR equalizers are able to perfectly recover one of the system inputs regardless of the initial settings. We then propose a novel algorithm for blind source separation and equalization for MIMO systems. Our theoretical analysis proves that the new blind algorithm is able to recover all system inputs simultaneously regardless of the initial settings. Finally, computer simulation examples are presented to confirm our analysis and illustrate the effectiveness of blind source separation and equalization for MIMO systems.
Adaptive negative cycle detection in dynamic graphs

We examine the problem of detecting negative cycles in a dynamic graph, which is a fundamental problem that arises in electronic design automation and systems theory. We introduce the concept of adaptive negative cycle detection, in which a graph changes over time, and negative cycle detection needs to be done periodically, but not necessarily after every individual change. Such scenarios arise, for example, during iterative design space exploration for hardware and software synthesis. We present an algorithm for this problem, called the Adaptive Bellman-Ford (ABF) algorithm, based on a novel extension of the well known Bellman-Ford algorithm. The ABF algorithm allows us to systematically adapt information for a given graph to a modified version of the graph. We show that the ABF algorithm significantly outperforms previously available approaches for dynamic graphs, which either recompute negative cycle information from scratch whenever a graph is modified, or process the modifications one at a time ("incrementally"). As an application of the ABF technique, we show that it can be used to obtain a very fast implementation of Lawler's technique for the computation of the maximum-cycle mean (MCM) of a graph, especially for a certain important kind of sparse graph. We further illustrate the application of the ABF technique to design-space exploration by developing automated search techniques for scheduling iterative data-flow graphs.
Power minimization for delivering integrated multimedia services over digital subscriber line

We study the problem of designing an efficient resource allocation scheme in the application of providing integrated multimedia services over a digital subscriber line. For a predefined quality of service (QoS) requirement and data throughput, we show that the transmitted power consumption can be reduced by applying the parallel transmission framework previously proposed. Data streams are recognized as a set of layers with different data rate and bit error rate requirements. The characteristics of the telephone channel can be utilized to provide unequal error protection naturally and thus efficiently. Simulation results provide comparison of the proposed parallel transmission framework to the existing schemes designed for general data, and demonstrate significant performance improvement, such as a 0.5-2 dB power gain.
Hierarchical group access control for secure multicast communications

Many group communications require a security infrastructure that ensures multiple levels of access control for group members. While most existing group key management schemes are designed for single level access control, we present a multi-group key management scheme that achieves hierarchical group access control. Particularly, we design an integrated key graph that maintains keying material for all members with different access privileges. It also incorporates new functionalities that are not present in conventional multicast key management, such as user relocation on the key graph. Analysis is performed to evaluate the storage and communication overhead associated key management. Comprehensive simulations are performed for various application scenarios where users statistical behavior is modelled using a discrete Markov chain. Compared with applying existing key management schemes directly to the hierarchical access control problem, the proposed scheme significantly reduces the overhead associated with key management and achieves better scalability.
Component Forensics of Digital Cameras: A Non-Intrusive Approach

This paper considers the problem of component forensics and proposes a methodology to identify the algorithms and parameters employed by various processing modules inside a digital camera. The proposed analysis techniques are non-intrusive, using only sample output images collected from the camera to find the color filter array pattern; and the algorithm and parameters of color interpolation employed in cameras. As demonstrated by various case studies in the paper, the features obtained from component forensic analysis provide useful evidence for such applications as detecting technology infringement, protecting intellectual property rights, determining camera source, and identifying image tampering.
A Graphical Evolutionary Game Approach to Social Learning

In this work, we study the social learning problem, in which agents of a networked system collaborate to detect the state of the nature based on their private signals. A novel distributed graphical evolutionary game-theoretic learning method is proposed. In the proposed game-theoretic method, agents only need to communicate their binary decisions rather than the real-valued beliefs with their neighbors, which endows the method with low communication complexity. Under mean field approximations, we theoretically analyze the steady-state equilibria of the game and show that the evolutionarily stable states coincide with the decisions of the benchmark centralized detector. Numerical experiments are implemented to confirm the effectiveness of the proposed game-theoretic learning method.
Transmit beamforming and power control for cellular wireless systems

Joint power control and beamforming schemes are proposed for cellular systems where adaptive arrays are used only at base stations. In the uplink, mobile power and receiver diversity combining vectors at the base stations are calculated jointly. The mobile transmitted power is minimized, while the signal-to-interference-and-noise ratio (SINR) at each link is maintained above a threshold. A transmit diversity scheme for the downlink is also proposed where the transmit weight vectors and downlink power allocations are jointly calculated such that the SINR at each mobile is above a target value. The proposed algorithm achieves a feasible solution for the downlink if there is one and minimizes the total transmitted power in the network. In a reciprocal network it can be implemented in a decentralized system, and it does not require global channel response measurements. In a nonreciprocal network, where the uplink and downlink channel responses are different, the proposed transmit beamforming algorithm needs to be implemented in a centralized system, and it requires a knowledge of the downlink channel responses. The performances of these algorithms are compared with previously proposed algorithms through numerical studies.
A game theoretical framework for dynamic pricing-based routing in self-organized MANETs

In self-organized mobile ad hoc networks (MANETs) where each user is its own authority, fully cooperative behaviors, such as unconditionally forwarding packets for each other or honestly revealing its private information, cannot be directly assumed. The pricing mechanism is one way to provide incentives for the users to act cooperatively by awarding some payment for cooperative behaviors. In this paper, we consider efficient routing in self-organized MANETs and model it as multi-stage dynamic pricing games. A game theoretical framework for dynamic pricing-based routing in MANETs is proposed to maximize the sender/receiveriquests payoff by considering the dynamic nature of MANETs. Meanwhile, the forwarding incentives of the relay nodes can also be maintained by optimally pricing their packet-forwarding services based on the auction rules and introducing the cartel maintenance enforcing mechanism. The simulation results illustrate that the proposed dynamic pricing-based routing approach has significant performance gains over the existing static pricing approaches.
On Antiforensic Concealability With Rate-Distortion Tradeoff

A signal's compression history is of particular forensic significance because it contains important information about the origin and authenticity of a signal. Because of this, antiforensic techniques have been developed that allow a forger to conceal manipulation fingerprints. However, when antiforensic techniques are applied to multimedia content, distortion may be introduced, or the data size may be increased. Furthermore, when compressing an antiforensically modified forgery, a tradeoff between the rate and distortion is introduced into the system. As a result, a forger must balance three factors, such as how much the fingerprints can be forensically concealed, the data rate, and the distortion, are interrelated to form a 3D tradeoff. In this paper, we characterize this tradeoff by defining concealability and using it to measure the effectiveness of an antiforensic attack. Then, to demonstrate this tradeoff in a realistic scenario, we examine the concealability-rate-distortion tradeoff in double JPEG compression antiforensics. To evaluate this tradeoff, we propose flexible antiforensic dither as an attack in which the forger can vary the strength of antiforensics. To reduce the time and computational complexity associated with decoding a JPEG file, applying antiforensics, and recompressing, we propose an antiforensic transcoder to efficiently complete these tasks in one step. Through simulation, two surprising results are revealed. One is that if a forger uses a lower quality factor in the second compression, applying antiforensics can both increase concealability and decrease the data rate. The other is that for any pairing of concealability and distortion values, achieved using a higher secondary quality factor, can also be achieved using a lower secondary quality factor at a lower data rate. As a result, the forger has an incentive to always recompress using a lower secondary quality factor.
Cooperative communications protocol for multiuser OFDM networks

This paper proposes a relay-based scheme where a fixed number of relays are utilized to design an OFDM cooperative protocol. By exploiting limited feedback from the destination terminal (central node) such that each relay is able to help forward information of multiple sources in one OFDM symbol, the proposed cooperative protocol not only achieves full diversity but also efficiently utilizes available bandwidth. A practical relay assignment scheme is also proposed to specify the pairing of sources and relays in cooperative networks. The outage probability analysis of the proposed cooperative protocol is provided, and the analytical results are validated via simulations. Moreover, a closed-form lower bound on the outage probability of any relay-assignment schemes is established to provide a performance benchmark of the proposed cooperative protocol. Based on the outage probability analysis, the optimum relay location for the proposed relay-assignment scheme is determined. Both theoretical and simulation results show that in WLAN scenario the proposed cooperative protocol can achieve significant coverage extension compared to the direct transmission.
A likelihood-based framework for quantification of brain receptor PET studies in the pixel domain

Quantification of receptor binding studies obtained with PET is complicated by tissue heterogeneity in the sampling image elements pixels and voxels. This effect is caused by a limited spatial resolution of the PET scanner. On the other hand, spatial heterogeneity is often essential in understanding the underlying receptor binding process. In this paper, we propose a likelihood-based framework in the pixel domain for quantitative imaging with or without the input function. Radioligand kinetic parameters are estimated together with the input function. The parameters are initialized by a subspace-based algorithm, and further refined by an iterative likelihood-based estimation procedure. The performances of the proposed scheme is examined by simulations. Real brain PET data are also examined to show the performance in determining the time activity curves and the underlying factor images.