ppxscal/embedding_network huggingface dataset:
Network assisted mobility support for 6LoWPAN
Authors: Gargi Bag, S. M. Saif Shams, Ali Hammad Akhbar, H. M. Muhammad Taqi Raza, Ki-Hyung Kim, Seung-wha Yoo
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

This paper presents a network-assisted mobility support scheme for 6LoWPAN nodes, which enables multi-hop communication between the Gateway (GW) and the Mobile 6LoWPAN devices (MNs), with minimum mobility related signaling at the MN's end as compared to conventional mobility related protocols like MIPv6. The scheme provides mobility support to the MNs with the help of low cost static 6LoWPAN devices (SNs) which can be deployed in large numbers. In order to reduce the handover latency, the MN in the proposed scheme is assigned a fixed address which remains unchanged during its course of movement within the network. Moreover the scheme aims to reduce packets loss of the MN by predicting its future location and having a provision of buffering its packet at SNs when needed. The signaling overhead consumption needed to support a MN is determined through analytical modeling.
Regularized referenceless temperature estimation in PRF-shift MR thermometry
Authors: William Grissom, Kim Butts Pauly, Michael Lustig, Viola Rieke, John Pauly, Nathan McDannold
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

In PRF-shift MR thermometry, temperature rises induced by thermal therapy can be estimated from the phase differences between tissue in a heated state and in a pretreatment state. To overcome errors caused by motion, referenceless methods [1, 2] have been proposed that estimate temperature from a single image. Compared to baseline subtraction [3], these methods are not susceptible to inter-frame motion, and produce accurate temperature estimates in moving tissues. However, referenceless methods could be improved if they did not require knowledge of the hot spot's location, or if they took into account underlying noise statistics. Here we introduce a regularized approach to referenceless PRF-shift thermometry that is statistically motivated, generalizes readily to multiple receive coils, and does not require knowledge of the hot spot's location.
DOA estimation based on the database retrieval technique with nonuniform quantization and clustering
Authors: Ivan Setiawan, Youji Iiguni
Venue: Digital Signal Processing (2004)

A direction-of-arrival (DOA) estimation method using an array antenna has been developed based on a database retrieval technique. This method uses a database consisting of a set of correlation matrices of the array output vectors for various combinations of the quantized angles and signal powers. When a correlation matrix is estimated from an observed output vector, several correlation matrices close to the estimated one are searched out from the database, and the DOA is estimated based on the retrieved data. This method gives an accurate estimation, but the use of uniform quantization step size requires a large amount of storage space. In this paper, the relation between the quantization step size and the estimation accuracy is analyzed, and a nonuniform quantization scheme is developed to reduce the database size without sacrificing the estimation accuracy. A clustering technique is also introduced to alleviate the performance degradation caused by the retrieval of data which have similar correlation matrices but have much different angles. We show by simulations that the nonuniform quantization reduces the database size and the clustering improves the estimation accuracy, and that the proposed method is applicable to the array of three elements at the present.
Ergodic interference alignment
Authors: Bobak Nazer, Michael Gastpar, Syed Ali Jafar, Sriram Vishwanath
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

Consider a K-user interference channel with time-varying fading. At any particular time, each receiver will see a signal from most transmitters. The standard approach to such a scenario results in each transmitter-receiver pair achieving a rate proportional to 1/K the single user rate. However, given two well chosen time indices, the channel coefficients from interfering users can be made to exactly cancel. By adding up these two signals, the receiver can see an interference-free version of the desired transmission. We show that this technique allows each user to achieve at least half its interference-free ergodic capacity at any SNR. Prior work was only able to show that half the interference-free rate was achievable as the SNR tended to infinity. We examine a finite field channel model and a Gaussian channel model. In both cases, the achievable rate region has a simple description and, in the finite field case, we prove it is the ergodic capacity region.
Optimal beaconing for 60 GHz millimeter wave
Authors: Joongheon Kim, BeomJin Jeon
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

This paper addresses optimal beacon fragmentation schemes for high-performance MAC in 60 GHz millimeter wave (mmWave) networks. The proposed optimal beacon scheme can be classified into two methods, i.e., differentiated and fragmentized beaconing. Differentiated and fragmentized beaconing schemes are for directional and omni-directional data transmission. By the result of performance evaluation, the novelty of the proposed schemes is verified.
Application of 3D local phase theory in vessel segmentation
Authors: Po Wang, Catherine Kelly, Michael Brady
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

The aim of this work is to segment, and quantify, the vasculature of tumours, based on fluorescent microscope 3D images. Such images have poor contrast and the vascular features vary substantially within a 3D volume. In this paper, we introduce a method to estimate local phase in 3D images based on the monogenic signal theory, and illustrate its performance on our vasculature images.
Design of authentication protocol for LR-WPAN using pre-authentication mechanism
Authors: Sung-Hyung Lee, Jae-Hyun Kim
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

This paper proposes a new authentication protocol for the LR-WPAN. In order to guarantee the reliability and safety of a protocol, this protocol uses the hierarchical authentication. In addition, in order to reduce the impact of the denial of service attack, the proposed protocol performs the authentication between a parent router and a joiner device prior to the authentication between a trust center and the joiner device. Moreover, this protocol reduces the authentication delay by decreasing the number of message exchanges during authentication. We evaluate the safety of the proposed protocol by the security analysis and compare the number of message exchanges of the ZigBee authentication protocol and the proposed protocol when denial of service attack occurs. We also analyze the delay for authentication of the joiner device through the implementation of both protocols. Those results show that the proposed protocol effectively protects networks from the denial of service attack and reduces the time for authenticating the joiner device up to maximum 30% as the number of hops increases.
Authenticating user using keystroke dynamics and finger pressure
Authors: H. Saevanee, P. Bhattarakosol
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Now mobile devices are developed to serve various functions, storing the sensitive information. As a consequence, the authentication of users for mobile devices has become an important issue. Additionally, the development of the mobile system is moving forward to the touch screen system for user friendly and quick access mechanism. In this paper, we proposed behavioral manners of users over the touchpad acting like touch screen that is able to detect finger pressure. We study the potential of each biometrics behavioral by individual and couple, comprise with hold-time, inter-key and finger pressure. The finding has shown that, the finger pressure gives the discriminative information more than keystroke dynamics with the PNN analytical method. Moreover, using only the finger pressure produces high accuracy rate of 99%.
Channel aware fuzzy logic hop selection for wireless sensor networks
Authors: Darminder Singh Ghataoura, Yang Yang, George Matich
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

Throughput and energy efficiency are two important parameters to evaluate the performance of a Wireless Sensor Network (WSN). For WSNs involved in varying channel conditions packet transmission reliability can be affected. This results in increased number of retransmissions and therefore energy consumption, with low throughput. Making optimal choices for robust packet transmission in this scenario is vital. For the purpose of this study a Fuzzy Logic System (FLS) is used as the decision mechanism for hop node selection. Both signal to noise ratio (SNR) and outage probability (Pout) are chosen parameters for the FLS, to decide upon hop node selection for reliable packet forwarding. Simulation results show that the proposed FLS does indeed provide advantages in improving on transmission reliability and energy efficiency performance, when operating in varying channel conditions.
Concavity of entropy under thinning
Authors: Yaming Yu, Oliver Johnson
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

Building on the recent work of Johnson (2007) and Yu (2008), we prove that entropy is a concave function with respect to the thinning operation Tα. That is, if X and Y are independent random variables on Z+ with ultra-log-concave probability mass functions, then H(TαX + T1-αY) ≥ αH(X) + (1 - α)H(Y), 0 ≤ α ≤ 1, where H denotes the discrete entropy. This is a discrete analogue of the inequality (h denotes the differential entropy) h(√αX + √1 - αY) ≥ αh(X) + (1 - α)h(Y), 0 ≤ α ≤ 1, which holds for continuous X and Y with finite variances and is equivalent to Shannon's entropy power inequality. As a consequence we establish a special case of a conjecture of Shepp and Olkin (1981). Possible extensions are also discussed.
Content-aware interface selection method for multipath video streaming in best-effort networks
Authors: Árpád Huszák, Sándor Imre
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

Today's mobile devices are equipped with multiple interfaces to make the connection possible to different type of networks. In order to efficiently utilize the interface capabilities, multi-path streaming can be used. Resource intensive applications can deliver high bitrate streams over multiple paths by cumulating the available bandwidth of the different subpaths. In this paper we propose a multi-path streaming method that chooses a set of paths maximizing the overall quality at the client. While the available paths have different bandwidth, delay and loss probability constrains, the packet distributor must take the video packet importance and the dependencies between packets into account. Transmitting the reference video frames on the most reliable links will decrease the loss probability of importaat data packets and increase the measured video quality. Both analytical and simulation analysis were performed to examine the behavior of the presented content-aware interface selection model. The results show that the proposed solution provides higher video quality thaa common scheduling algorithms.
Some properties of Alamouti-like MISO codes
Authors: Roope Vehkalahti
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

In this paper we are discussing multiple-input single-output (MISO) transmission in slowly fading channel with two transmit and one receiving antenna. Particularly we are concentrating on properties of division algebra based Alamouti-like space-time block codes. The main contributions of this paper are the following. First we extend the previously done constructions by considering general orders and give a simple proof that the proposed family of codes is approximately universal in the slow fading channel. Further we give a method to measure the pairwise error probability (PEP)-oriented normalized coding gain of the proposed codes and explore the frontiers of the achievable coding gain.
Generating functional analysis of LDGM channel coding with many short loops
Authors: Kazushi Mimura, A. C. C. Coolen
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We study the dynamics of a simple message-passing decoder for LDGM channel coding by using the generating functional analysis (GFA). The decoder addressed here is one of the simplest examples, which is characterized by a sparse random graph with many short loops. The GFA allows us to study the dynamics of iterative systems in an exact way in the large codeword length limit.
Quantitative multiparametric two-photon imaging of tissues
Authors: Irene Georgakoudi, Jonathan Levitt, William Rice, David Kaplan
Venue: Proceedings of the Sixth IEEE international conference on Symposium on Biomedical Imaging: From Nano to Macro (2009)

The characterization of engineered tissue development has been performed via invasive means that have limited abilities to capture the dynamic nature of the interactions and changes that occur. Optical spectroscopic imaging could serve as a non-invasive approach to overcome this limitation. Implemented on a two-photon microscopy platform, spectroscopic imaging can provide information on the biochemistry, structure and organization of the cellular, extracellular matrix and biomaterial scaffolds that make up engineered tissues. We find that distinct spectral shifts characterize the secondary structure of biomaterial silk scaffolds, as well as the differentiation status of epithelial and mesenchymal stem cells. The knowledge we gain is relevant not only for the optimization of tissue regeneration, but also for disease diagnostic and therapeutic applications.
Design and implementation of security camera control application for mobile phones
Authors: Takeshi Kato, Tomoyuki Osano, Norihiro Ishikawa
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

In recent years, due to the rise in crime, growing numbers of governments, companies, and schools are equipping their facilities with security cameras to deter crime and to investigate crimes that have happened. In this study, we investigate a distributed application that provides an efficient access method for security cameras placed in various areas. Peer-to-peer is a suitable technology for such ubiquitous applications since it supports discovery mechanisms, simple one-to-one communication, free and extensible distribution of resources, and distributed search to handle the enormous number of resources expected. Our system uses protocols defined by Peer-to-peer Universal Computing Consortium (PUCC) to control various kinds of devices over a peer-to-peer network. This paper presents the design and implementation of a camera control protocol on the PUCC platform for controlling security cameras from mobile phones. The prototype implementation system consists of a media gateway to deliver streaming video to multiple mobile phones and proxies to serve as peer-to-peer nodes for cameras. Camera control and signaling protocols for video streaming are realized by using PUCC protocols.
High-resolution speech signal reconstruction in wireless sensor networks
Authors: Andria Pazarloglou, Radu Stoleru, Ricardo Gutierrez-Osuna
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Data streaming is an emerging class of applications for sensor networks that has very high bandwidth and processing power requirements. In this paper, a new approach for speech data streaming is proposed, which is based on a distributed scheme. This scheme focuses on balancing the energy consumption among nodes in a sensor network by allowing lowresolution streams from multiple nodes to be fused at a central processing node in order to produce an enhanced resolution speech signal. Simulations and experimental results with real microphone signals are presented.
Delay with network coding and feedback
Authors: Eleni Drinea, Christina Fragouli, Lorenzo Keller
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

We consider the problem of minimizing delay when broadcasting over erasure channels with feedback. A sender wishes to communicate the same set of µ messages to several receivers over separate erasure channels. The sender can broadcast a single message or a combination (encoding) of messages at each timestep. Receivers provide feedback as to whether the transmission was received. If at some time step a receiver cannot identify a new message, delay is incurred. Our notion of delay is motivated by real-time applications that request progressively refined input, such as the successive refinement of an image encoded using multiple description coding. Our setup is novel because it combines coding techniques with feedback information to the end of minimizing delay. It allows Θ(µ) benefits as compared to previous approaches for offline algorithms, while feedback allows online algorithms to achieve smaller delay than online algorithms without feedback. Our main complexity results are that the offline minimization problem is NP-hard when the sender only schedules single messages and that the general problem remains NP-hard even when coding is allowed. However we show that coding does offer delay and complexity gains over scheduling. We also discuss online heuristics and evaluate their performance through simulations.
Hypervisors for consumer electronics
Authors: Gernot Heiser
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Virtualization, well established in enterprise computing, is finding its way into embedded systems. However, the use cases differ dramatically between the domains, and this results in significant differences in the requirements on the virtual-machine technology. This paper examines a number of typical virtualization use cases from the CE domain, and the resulting requirements imposed on the hypervisor. We find that enterprise-style hypervisors are ill-matched to the requirements of the embedded domain, which are characterised by low-overhead communication, real-time capability, small memory footprint, small trusted computing base, and fine-grained control over security. We present the OKL4 hypervisor, a member of the L4 microkernel family, designed for embedded-systems use. We outline OKL4's relevant properties with an emphasis on its security mechanisms, and compare its performance to a version of Xen that has recently been promoted for CE use. We conclude that OKL4 is superior to enterprise-style hypervisors for use in CE devices.
Distributed source coding without Slepian-Wolf compression
Authors: Yang Yang, Zixiang Xiong
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

Slepian-Wolf (SW) coding, which is concerned with separate near-lossless compression of correlated sources (with joint decoding), forms the basis of distributed source coding (DSC) and can be used to exploit the correlation among quantized sources in lossy DSC problems such as Wyner-Ziv (WZ) coding and multiterminal (MT) source coding. However, SW coding is in general lossy, especially at short block length, and practical implementation is not nearly as well understood as entropy coding. This paper studies distributed source coding without SW coding. We employ entropy coding (after quantization if necessary) at each encoder while relying on joint estimation at the decoder to exploit the source correlation. We start from the simple lossless case before giving single-letter characterizations of the rate-distortion function for WZ coding without SW compression, and achievable rate region for MT source coding without SW compression. Examples on the binary symmetric and quadratic Gaussian cases are given.
Two-way source coding with a common helper
Authors: Haim Permuter, Yossef Steinberg, Tsachy Weissman
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

Consider the two-way rate-distortion problem in which a helper sends a common limited-rate message to both users based on side information at its disposal. We characterize the region of achievable rates and distortions where a Markov form (Helper)-(User 1)-(User 2) holds. The main insight of the result is that in order to achieve the optimal rate, the helper may use a binning scheme, as in Wyner-Ziv, where the side information at the decoder is the "further" user, namely, User 2. The converse proofs use a new technique for verifying Markov relations via undirected graphs.
Entanglement transmission capacity of compound channels
Authors: Igor Bjelakovic, Holger Boche, Janis Nötzel
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We determine the optimal achievable rate at which entanglement can be reliably transmitted when the memoryless channel used during transmission is unknown both to sender and receiver. To be more precise, we assume that both of them only know that the channel belongs to a given set of channels. Thus, they have to use encoding and decoding schemes that work well for the whole set.
Distributed differential space-time codes based on Weyl's reciprocity
Authors: Haiquan Wang, Zhijin Zhao
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

In this paper, design of a distributed differential space time code is considered. To satisfy the commuting property required in the design, Weyl reciprocity is hired. Introducing methods and illustrating examples show that the proposed methods have more flexible, and more easy to get codes than existing methods, especially in a case with high dimensional unitary matrices and a large number of relays.
On the support of multimedia applications over IEEE 802.11-based wireless mesh networks
Authors: Roberto Riggio, Karina Gomez, Tinku Rasheed
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

The extended radio coverage provided by wireless mesh networking (WMN) technologies represents a key advantage compared to the last mile solutions based on standard IEEE 802.11 hot spots. Nevertheless, modern requirements to wireless connectivity include mandatory QoS guarantees for a wide set of real-time applications. In this paper, we first propose a methodology for evaluating multimedia applications over real world WMN deployments and then we report the results of an extensive measurement campaign performed exploiting IEEE 802.11-based WMN testbed. Later, we evaluate the QoS performance of the reference multimedia applications exploiting three different link scheduling disciplines. Results show that, using opportunistic scheduling techniques capable of providing performance isolation among competing flows can significantly improve system capacity.