3D image segmentation is a fundamental process in many scientific and medical applications. Automatic algorithms do exist, but there are many use cases where these algorithms fail. The gold standard is still manual se...
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ISBN:
(纸本)9781450341257
3D image segmentation is a fundamental process in many scientific and medical applications. Automatic algorithms do exist, but there are many use cases where these algorithms fail. The gold standard is still manual segmentation or review. Unfortunately, even for an expert this is laborious, time consuming, and prone to errors. Existing 3D segmentation tools do not currently take into account human mental models and low-level perception tasks. Our goal is to improve the quality and efficiency of manual segmentation and review by analyzing how experts perform segmentation. As a preliminary step we conducted a field study with 8 segmentation experts, recording video and eye tracking data. We developed a novel coding scheme to analyze this data and verified that it successfully covers and quantifies the low-level actions, tasks and behaviors of experts during 3D image segmentation.
Relay-based cellular networks are likely to play an important role in the race for energy efficiency. However, potential gains greatly depend on how relay stations are deployed within the cell. Using a geometrical mod...
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ISBN:
(纸本)9781479944491
Relay-based cellular networks are likely to play an important role in the race for energy efficiency. However, potential gains greatly depend on how relay stations are deployed within the cell. Using a geometrical model for energy-efficient analysis, we investigate the impact of the number and location of relays on energy consumption, and its dependence on the relay coding scheme and the propagation environment, i.e. the pathloss and the line-of-sight conditions. In addition to the transmit energy, we account for the economic cost of relay deployment, as well as the overhead energy dissipated at each relay stations due to data processing and network maintenance. We then bring out four key trade-offs which balance the cost and flexibility of relay deployment, the energy efficiency and the coverage extension.
Random I/O (RIO) Codes, recently introduced by Sharon and Alrod, is a coding scheme to improve the random input/output performance of flash memories. Multi-level flash memories require, on the average, more than a sin...
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ISBN:
(纸本)9781479959990
Random I/O (RIO) Codes, recently introduced by Sharon and Alrod, is a coding scheme to improve the random input/output performance of flash memories. Multi-level flash memories require, on the average, more than a single read threshold in order to read a single logical page. This number is important to be optimized since it sets the read latency of flash memories. An (n, M, t) RIO code assumes that t pages are stored in n cells with t 1 levels. The first page is read by applying a read threshold between levels t and t + 1. Similarly, the second page is read by applying a read threshold between levels t 1 and t, and so on. The read binary vectors for consecutive pages satisfy the property that the set of positions read with value 1 can only increase. Therefore, Sharon and Alrod showed also that the design of RIO codes is equivalent to the design of WOM codes. The latter family of codes attracted a lot of attention in recent years in order to improve the lifetime of flash memories by allowing to write multiple messages to the memory without the need for a physical erase. In this paper we notice two important distinctions between RIO codes and WOM codes. While in WOM codes the messages are received one after the other and thus are not known all in advance, in RIO codes the information of all logical pages can be known in advance when programming the cells. Even though this knowledge does not improve the capacity of RIO codes, it allows the design of efficient high-rate codes with a moderate block length, which are hard to be found for WOM codes. We also study another family of RIO codes, called here partial RIO Codes, that allow to find even more efficient codes in the tradeoff of reading more than a single threshold to read a page.
This paper is concerned with GSM-EDGE system simulation and bit error ratio evaluation of the transmitted signal over AWGN and Rayleigh fading channel. The goal is to observe the impact of radio channel on variously m...
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ISBN:
(纸本)9781424420872
This paper is concerned with GSM-EDGE system simulation and bit error ratio evaluation of the transmitted signal over AWGN and Rayleigh fading channel. The goal is to observe the impact of radio channel on variously modulated and coded GSM-EDGE signals. The block scheme and proposed model of signal processing in the downlink direction is described step by step. Simulation results for various modulation and coding schemes (MCS) are graphically presented. In order to gel. the required results, the simulation tool was created in MATLAB environment.
Golay binary complementary sequences are used to code quadriphase waveforms. The Gaussian minimum shift keying coding scheme is used to produce waveforms with constant amplitude, and continuous and differentiable phas...
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Golay binary complementary sequences are used to code quadriphase waveforms. The Gaussian minimum shift keying coding scheme is used to produce waveforms with constant amplitude, and continuous and differentiable phase. To satisfy spectral requirements, the waveforms are further spectrally optimised by a spectrum-optimisation process, making the final waveforms implementable. The extra-low sidelobe level is achieved by the use of an extended mismatched filter on receive of pulse compression. To improve Doppler tolerance, Doppler-resilient complementary waveforms are derived that provide first-order suppression to the raised range sidelobes introduced by the Doppler frequency shift in returned signals. This study is an expanded version of a conference paper presented at 2018 International Radar Conference held in Brisbane, Australia.
Emerging non-volatile memory devices show tremendous promise for a wide variety of applications, ranging from consumer electronics to server technologies. The advent of such multi-scale opportunities also carries a un...
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ISBN:
(纸本)9781424488650
Emerging non-volatile memory devices show tremendous promise for a wide variety of applications, ranging from consumer electronics to server technologies. The advent of such multi-scale opportunities also carries a unique set of challenges. Increasingly popular Flash memory devices possess an intrinsic asymmetry during the write operation: programming memory cells to values lower than currently stored values is considerably slower and more costly than programming to higher values. It is critical to keep this cost low, as it directly affects memory lifetime and performance. Concurrently, demands for higher densities under reduced technology sizing make the data reliability a formidable objective. To address the compound issue of sustained and low-cost data reliability and high performance, in this work we propose a methodology to provide guaranteed immunity to a prescribed number of asymmetric errors, while having asymptotically negligible redundancy. Our construction uses ideas from additive and combinatorial number theory, and builds upon recently introduced coding schemes. We first show how this construction can be used in the single level cell (SLC) setup, and subsequently extend the construction to the setting with several levels per cell, including multi-level cell (MLC) and triple-level (TLC) setting. We also discuss practical aspects of such schemes, including methods for systematic encoding, correction of limited-magnitude errors, and the additional protection under a certain number of bidirectional errors. This number-theoretic based approach is a promising direction for extending the lifetime of memories at sustained reliability.
Recently there has been a lot of success in using the deterministic approach to provide approximate characterization of Gaussian network capacity. In this paper, we take a deterministic view and revisit the problem of...
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ISBN:
(纸本)9781457705953
Recently there has been a lot of success in using the deterministic approach to provide approximate characterization of Gaussian network capacity. In this paper, we take a deterministic view and revisit the problem of wiretap channel with side information. A precise characterization of the secrecy capacity is obtained for a linear deterministic model, which naturally suggests a coding scheme which we show to achieve the secrecy capacity of the degraded Gaussian model (dubbed as "secret writing on dirty paper") to within (1/2) log 3 bits.
Going beyond mere forum posts categorization is key to understand why some students struggle and eventually fail in MOOCs. We propose here an extension of a coding scheme and present the design of the associated autom...
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ISBN:
(纸本)9781450368049
Going beyond mere forum posts categorization is key to understand why some students struggle and eventually fail in MOOCs. We propose here an extension of a coding scheme and present the design of the associated automatic annotation tools to tag students' questions in their forum posts. Working of four sessions of the same MOOC, we cluster students' questions and show how the obtained clusters are consistent across all sessions and can be sometimes correlated with students' success in the MOOC. Moreover, it helps us better understand the nature of questions asked by successful vs. unsuccessful students.
We study a multiple-terminal joint source-channel coding problem, where two remote correlated Gaussian sources are transmitted over a Gaussian multiple-access channel with two transmitters. Each transmitter observes o...
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ISBN:
(纸本)9781457705953
We study a multiple-terminal joint source-channel coding problem, where two remote correlated Gaussian sources are transmitted over a Gaussian multiple-access channel with two transmitters. Each transmitter observes one of the sources contaminated in Gaussian noise. The receiver wishes to reconstruct both sources. We derive necessary conditions and sufficient conditions for the receiver to be able to reconstruct the sources with given expected squared-error distortions. These conditions establish the optimality of uncoded transmission below some signal-to-noise ratio (SNR) threshold, and they also establish the high-SNR asymptotics. To achieve the latter, a coding scheme is proposed that superimposes analog uncoded transmission and digital combined source-channel Gaussian vector quantization.
The image-based lip animation synthesis approach is one kind of promising method that synthesizes the believable talking head. This paper seeks to show an improvement in the accuracy of mouth prediction with the speec...
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ISBN:
(纸本)9781424404759
The image-based lip animation synthesis approach is one kind of promising method that synthesizes the believable talking head. This paper seeks to show an improvement in the accuracy of mouth prediction with the speech stimulus, as well as showing the method used to extract the speaking mouth correlative speech feature. Our lip animation synthesis system is based on the construction of a frame level audiovisual mapping model between the acoustic speech class and speaking mouth image class. Taking the mapping model as a basis, genetic algorithm is used to extract the speaking mouth correlative speech feature. The key step used in this study is: fitness and coding scheme designing. Experimental results show that the extracted speech feature has a better correlation with the corresponding speaking mouth, compared to the single or mixed LPCC and MFCC. More research will be done in this specialist field of study the multi-layer speaking mouth correlative speech feature abstraction structure, and will attempt to show that the speaking mouth correlative speech feature should have better results.
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