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2017 25th European Signal Processing Conference (EUSIPCO)最新文献

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Airfare prices prediction using machine learning techniques 利用机器学习技术预测机票价格
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081365
K. Tziridis, T. Kalampokas, G. Papakostas, K. Diamantaras
This paper deals with the problem of airfare prices prediction. For this purpose a set of features characterizing a typical flight is decided, supposing that these features affect the price of an air ticket. The features are applied to eight state of the art machine learning (ML) models, used to predict the air tickets prices, and the performance of the models is compared to each other. Along with the prediction accuracy of each model, this paper studies the dependency of the accuracy on the feature set used to represent an airfare. For the experiments a novel dataset consisting of 1814 data flights of the Aegean Airlines for a specific international destination (from Thessaloniki to Stuttgart) is constructed and used to train each ML model. The derived experimental results reveal that the ML models are able to handle this regression problem with almost 88% accuracy, for a certain type of flight features.
本文主要研究机票价格预测问题。为此,假设这些特征会影响机票的价格,就确定了一组典型航班的特征。这些特征被应用到8个最先进的机器学习(ML)模型中,用于预测机票价格,并对模型的性能进行比较。在研究各个模型的预测精度的同时,本文还研究了预测精度与用于表示机票的特征集的依赖关系。对于实验,构建了一个由爱琴海航空公司1814个特定国际目的地(从塞萨洛尼基到斯图加特)的数据航班组成的新数据集,并用于训练每个ML模型。衍生的实验结果表明,对于特定类型的飞行特征,ML模型能够以近88%的准确率处理该回归问题。
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引用次数: 42
Person re-identification based on deep multi-instance learning 基于深度多实例学习的人物再识别
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081471
D. Varga, T. Szirányi
Person re-identification is one of the widely studied research topic in the fields of computer vision and pattern recognition. In this paper, we present a deep multi-instance learning approach for person re-identification. Since most publicly available databases for pedestrian re-identification are not enough big, over-fitting problems occur in deep learning architectures. To tackle this problem, person re-identification is expressed as a deep multi-instance learning issue. Therefore, a multi-scale feature learning process is introduced which is driven by optimizing a novel cost function. We report on experiments and comparisons to other state-of-the-art algorithms using publicly available databases such as VIPeR and ETHZ.
人的再识别是计算机视觉和模式识别领域中被广泛研究的课题之一。本文提出了一种基于深度多实例学习的人物再识别方法。由于大多数用于行人重新识别的公开数据库不够大,深度学习架构中会出现过拟合问题。为了解决这一问题,将人的再识别表达为一个深度多实例学习问题。为此,引入了一种以优化新的代价函数为驱动的多尺度特征学习过程。我们报告了使用公共数据库(如VIPeR和ETHZ)的实验和与其他最先进算法的比较。
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引用次数: 2
Boosting LINC systems combiners efficiency through ring-type magnitude modulation 通过环形幅度调制提高LINC系统组合效率
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081607
Mario Castanheira, Antônio Simoes, M. Gomes, R. Dinis, V. Silva
This paper proposes a transmitter structure that combines a ring-type magnitude modulation (RMM) technique with a linear amplification with nonlinear components (LINC) scheme for power and spectrally efficient transmission based on bandwidth limited OQPSK signals, for either a linear combiner (LC) or a Chireix combiner (CC). It shows that by controlling the transmitted signal's envelope through RMM, the range of the LINC decomposition angle is considerably decreased. This significantly improves LC's power efficiency, and substantially reduces CC's spectral leakage while maintaining its high amplification efficiency.
本文提出了一种结合环形幅度调制(RMM)技术和非线性分量线性放大(LINC)方案的发射机结构,用于基于带宽有限的OQPSK信号的功率和频谱高效传输,适用于线性组合器(LC)或Chireix组合器(CC)。结果表明,通过RMM对发射信号包络线进行控制,大大减小了LINC分解角的范围。这大大提高了LC的功率效率,在保持其高放大效率的同时大幅降低了CC的频谱泄漏。
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引用次数: 0
Person identity recognition on motion capture data using label propagation 基于标签传播的动作捕捉数据的身份识别
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081312
N. Nikolaidis, Charalambos Symeonidis
Most activity-based person identity recognition methods operate on video data. Moreover, the vast majority of these methods focus on gait recognition. Obviously, recognition of a subject's identity using only gait imposes limitations to the applicability of the corresponding methods whereas a method capable of recognizing the subject's identity from various activities would be much more widely applicable. In this paper, a new method for activity-based identity recognition operating on motion capture data, that can recognize the subject's identity from a variety of activities is proposed. The method combines an existing approach for feature extraction from motion capture sequences with a label propagation algorithm for classification. The method and its variants (including a novel one, that takes advantage of the fact that, in certain cases, both activity and person identity labels might exist for the labeled sequences) have been tested in two different datasets. Experimental analysis proves that the proposed approach provides very good person identity recognition results, surpassing those obtained by two other methods.
大多数基于活动的人物身份识别方法都是基于视频数据的。此外,这些方法绝大多数都集中在步态识别上。显然,仅通过步态识别受试者身份限制了相应方法的适用性,而能够从各种活动中识别受试者身份的方法将更广泛地适用。本文提出了一种基于动作捕捉数据的基于活动的身份识别新方法,该方法可以从多种活动中识别主体的身份。该方法将现有的运动捕捉序列特征提取方法与标签传播分类算法相结合。该方法及其变体(包括一种新颖的方法,它利用了这样一个事实,即在某些情况下,标记的序列可能同时存在活动和个人身份标签)已经在两个不同的数据集中进行了测试。实验分析表明,该方法具有较好的人物身份识别效果,优于其他两种方法。
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引用次数: 0
Separation of vibration-derived sound signals based on fusion processing of vibration sensors and microphones 基于振动传感器与传声器融合处理的振动声信号分离
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081646
R. Takashima, Y. Kawaguchi, M. Togami
This paper proposes a sound source separation method for vibration-derived sound signals such as sounds derived from mechanical vibrations by using vibration sensors. The proposed method is based on two assumptions. First, a vibration signal and the sound derived from the vibration are assumed to have a linear correlation. This assumption enables us to model the vibration-derived sound as a linear convolution of a transfer function and a vibration signal recorded by a vibration sensor. Second, un-vibration-derived sound signals such that the sound source is not connected to vibration sensors via a solid medium are barely recorded by vibration sensors. This assumption leads to a constraint of the transfer function from the un-vibration-derived sound sources to the vibration sensors. The proposed framework is the same as a microphone-array-based blind source separation framework, except that the proposed method constructs arrays with microphones and vibration sensors, and the separation parameters are constrained by the prior knowledge gained from the above second assumption. Experimental results indicate that the separation performance of the proposed method is superior to that of a conventional microphone-array-based source separation method.
本文提出了一种利用振动传感器分离机械振动声等振动源声信号的方法。该方法基于两个假设。首先,假设振动信号和由振动产生的声音具有线性相关关系。这个假设使我们能够将振动衍生的声音建模为传递函数和振动传感器记录的振动信号的线性卷积。其次,非振动产生的声音信号,即声源不通过固体介质连接到振动传感器,几乎不被振动传感器记录。这一假设导致了从非振动源到振动传感器的传递函数的约束。该框架与基于麦克风阵列的盲源分离框架相同,不同之处在于该方法构建了麦克风和振动传感器的阵列,并且分离参数受到由上述第二个假设获得的先验知识的约束。实验结果表明,该方法的分离性能优于传统的基于麦克风阵列的源分离方法。
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引用次数: 1
Rapid bird activity detection using probabilistic sequence kernels 基于概率序列核的鸟类活动快速检测
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081510
Anshul Thakur, R. Jyothi, Padmanabhan Rajan, A. D. Dileep
Bird activity detection is the task of determining if a bird sound is present in a given audio recording. This paper describes a bird activity detector which utilises a support vector machine (SVM) with a dynamic kernel. Dynamic kernels are used to process sets of feature vectors having different cardinalities. Probabilistic sequence kernel (PSK) is one such dynamic kernel. The PSK converts a set of feature vectors from a recording into a fixed-length vector. We propose to use a variant of PSK in this work. Before computing the fixed-length vector, cepstral mean and variance normalisation and short-time Gaussianization is performed on the feature vectors. This reduces environment mismatch between different recordings. Additionally, we also demonstrate a simple procedure to speed up the proposed method by reducing the size of fixed-length vector. A speedup of almost 70% is observed, with a very small drop in accuracy. The proposed method is also compared with a random forest classifier and is shown to outperform it.
鸟类活动检测的任务是确定在给定的音频记录中是否存在鸟类的声音。本文介绍了一种基于动态核的支持向量机的鸟类活动检测器。动态核用于处理具有不同基数的特征向量集。概率序列核(PSK)就是一种动态核。PSK将记录中的一组特征向量转换为固定长度的向量。我们建议在这项工作中使用PSK的一种变体。在计算固定长度向量之前,对特征向量进行倒谱均值和方差归一化和短时高斯化。这减少了不同录音之间的环境不匹配。此外,我们还演示了一个简单的过程,通过减少固定长度向量的大小来加快所提出的方法。可以观察到几乎70%的加速,而精度却有很小的下降。该方法还与随机森林分类器进行了比较,结果表明其优于随机森林分类器。
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引用次数: 11
Low-rank and nonlinear model approach to image inpainting 图像绘制的低秩非线性模型方法
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081224
Ryohei Sasaki, K. Konishi, Tomohiro Takahashi, T. Furukawa
This paper proposes a new algorithm for image inpainting algorithm based on the matrix rank minimization with nonlinear mapping function. Assuming that each intensity value of a nonlinear mapped image can be modeled by the autoregressive (AR) model, the image inpainting problem is formulated as a kind of the matrix rank minimization problem, and this paper modifies the iterative partial matrix shrinkage (IPMS) algorithm and provides an inpainting algorithm, which estimates a nonlinear mapping function and the missing pixels simultaneously. Numerical examples show that the proposed algorithm recovers missing pixels efficiently.
本文提出了一种基于非线性映射函数的矩阵秩最小化的图像绘制算法。假设非线性映射图像的每个强度值都可以用自回归(AR)模型建模,将图像的上色问题化为一种矩阵秩最小化问题,并对迭代部分矩阵收缩(IPMS)算法进行改进,提出了一种同时估计非线性映射函数和缺失像素的上色算法。数值算例表明,该算法能有效地恢复缺失像素。
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引用次数: 1
Fine-scale patterns driving dynamic functional connectivity provide meaningful brain parcellations 驱动动态功能连接的精细模式提供了有意义的大脑包裹
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081691
M. Preti, D. Ville
Dynamic functional connectivity (dFC) derived from resting-state functional magnetic resonance imaging (fMRl) allows identifying large-scale functional brain networks based on spontaneous activity and their temporal reconfigurations. Due to limited memory and computational resources, these pairwise measures are typically computed for a set of brain regions from a pre-defined brain atlas, which choice is non-trivial and might influence results. Here, we first leverage the availability of dynamic information and new computational methods to retrieve dFC at the finest voxel level in terms of dominant patterns of fluctuations, and, second, we demonstrate that this new representation is informative to derive meaningful brain parcellations that capture both long-range interactions and fine-scale local organization. We analyzed resting-state fMRI of 54 healthy participants from the Human Connectome Project. For each position of a temporal window, we determined eigenvector centrality of the windowed fMRl data at the voxel level. These were then concatenated across time and subjects and clustered into the most representative dominant patterns (RDPs). Each voxel was then labeled according to a binary code indicating positive or negative contribution to each of the RDPs. We obtained a 36-label parcellation displaying long-range interactions with remarkable hemispherical symmetry. By separating contiguous regions, a finer-scale parcellation of 448 areas was also retrieved, showing consistency with known connectivity of cortical/subcortical structures including thalamus. Our contribution bridges the gap between voxel-based approaches and graph theoretical analysis.
动态功能连接(dFC)来源于静息状态功能磁共振成像(fMRl),可以识别基于自发活动及其时间重构的大规模功能脑网络。由于有限的内存和计算资源,这些两两测量通常是从预定义的脑图谱中计算一组脑区域,其中的选择是非平凡的,可能会影响结果。在这里,我们首先利用动态信息的可用性和新的计算方法,在最精细的体素水平上检索dFC的主要波动模式,其次,我们证明了这种新的表示是有意义的信息,可以获得捕获远程相互作用和精细尺度局部组织的有意义的大脑分割。我们分析了来自人类连接组项目的54名健康参与者的静息状态功能磁共振成像。对于时间窗口的每个位置,我们在体素水平上确定窗口fMRl数据的特征向量中心性。然后将这些数据按时间和对象进行连接,并聚集成最具代表性的主导模式(rdp)。然后根据二进制代码标记每个体素,表示对每个rdp的积极或消极贡献。我们获得了36个标签的包封,显示具有显著的半球形对称性的远程相互作用。通过分离连续区域,还检索了448个区域的更精细的分组,显示了与包括丘脑在内的皮质/皮质下结构的已知连通性的一致性。我们的贡献弥合了基于体素的方法和图理论分析之间的差距。
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引用次数: 1
Optimal design of sparse MIMO arrays for near-field ultrawideband imaging 稀疏MIMO阵列近场超宽带成像优化设计
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081550
M. B. Kocamis, F. Oktem
Near-field ultrawideband imaging is a promising remote sensing technique in various applications such as airport security, surveillance, medical diagnosis, and through-wall imaging. Recently, there has been increasing interest in using sparse multiple-input-multiple-output (MIMO) arrays to reduce hardware complexity and cost. In this paper, based on a Bayesian estimation framework, an optimal design method is presented for two-dimensional MIMO arrays in ultrawideband imaging. The optimality criterion is defined based on the image reconstruction quality obtained with the design, and the optimization is performed over all possible locations of antenna elements using an algorithm called clustered sequential backward selection algorithm. The designs obtained with this approach are compared with that of some commonly used sparse array configurations in terms of image reconstruction quality for various noise levels.
近场超宽带成像是一种具有广阔应用前景的遥感技术,可用于机场安检、监视、医疗诊断和穿墙成像等领域。近年来,人们对使用稀疏多输入多输出(MIMO)阵列来降低硬件复杂性和成本越来越感兴趣。提出了一种基于贝叶斯估计框架的二维MIMO阵列超宽带成像优化设计方法。根据设计获得的图像重建质量定义最优性准则,并使用聚类顺序向后选择算法对天线单元的所有可能位置进行优化。用这种方法得到的设计在不同噪声水平下的图像重建质量方面与一些常用的稀疏阵列设计进行了比较。
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引用次数: 5
Constant modulus beamforming for large-scale MISOME wiretap channel 大规模MISOME窃听信道的恒模波束成形
Pub Date : 2017-08-01 DOI: 10.23919/EUSIPCO.2017.8081669
Qiang Li, Chao-xu Li, Jingran Lin
The multi-input single-output multi-eavesdropper (MISOME) wiretap channel is one of the generic wiretap channels in physical layer security. In Khisti and Wornell's classical work [1], the optimal secure beamformer for MISOME has been derived under the total power constraint. In this work, we revisit the MISOME wiretap channel and focus on the large-scale transmit antenna regime and the constant modulus beamformer design. The former is motivated by the significant spectral efficiency gains provided by massive antennas, and the latter is due to the consideration of cheap hardware implementation of constant modulus beamforming. However, from an optimization point of view, the secrecy beamforming with constant modulus constraints is challenging, more specifically, NP-hard. In light of this, we propose two methods to tackle it, namely the semidefinite relaxation (SDR) method and the ADMM-Dinkelbach method. Simulation results demonstrate that the ADMM-Dinkelbach method outperforms the SDR method, and can attain nearly optimal secrecy performance for the large-scale antenna scenario.
多输入单输出多窃听者(MISOME)窃听通道是物理层安全中常用的窃听通道之一。Khisti和Wornell的经典著作[1]推导了总功率约束下MISOME的最优安全波束形成器。在这项工作中,我们重新审视MISOME窃听信道,重点关注大规模发射天线体制和恒模波束形成器设计。前者的动机是由于大量天线提供了显著的频谱效率增益,而后者是由于考虑到恒模波束形成的廉价硬件实现。然而,从优化的角度来看,具有恒定模量约束的保密波束形成具有挑战性,更具体地说,是np困难。鉴于此,我们提出了半定松弛(SDR)法和ADMM-Dinkelbach法两种解决方法。仿真结果表明,ADMM-Dinkelbach方法优于SDR方法,在大规模天线场景下可以获得近乎最优的保密性能。
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引用次数: 5
期刊
2017 25th European Signal Processing Conference (EUSIPCO)
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