Investigation of vocal jitter and glottal flow spectrum as possible cues for depression and near-term suicidal risk

Among the many clinical decisions that psychiatrists must make, assessment of a patient's risk of committing suicide is definitely among the most important, complex, and demanding. When reviewing his clinical experience, one of the authors observed that successful predictions of suicidality were often based on the patient's voice independent of content. The voices of suicidal patients judged to be high-risk near-term exhibited unique qualities, which distinguished them from nonsuicidal patients. We investigated the discriminating power of two excitation-based speech parameters, vocal jitter and glottal flow spectrum, for distinguishing among high-risk near-term suicidal, major depressed, and nonsuicidal patients. Our sample consisted of ten high-risk near-term suicidal patients, ten major depressed patients, and ten nondepressed control subjects. As a result of two sample statistical analyses, mean vocal jitter was found to be a significant discriminator only between suicidal and nondepressed control groups (p < 0.05). The slope of the glottal flow spectrum, on the other hand, was a significant discriminator between all three groups (p < 0.05). A maximum likelihood classifier, developed by combining the a posteriori probabilities of these two features, yielded correct classification scores of 85% between near-term suicidal patients and nondepressed controls, 90% between depressed patients and nondepressed controls, and 75% between near-term suicidal patients and depressed patients. These preliminary classification results support the hypothesized link between phonation and near-term suicidal risk. However, validation of the proposed measures on a larger sample size is necessary.     

Energy and power of bandlimited fields in lossless nonlinear media

For nonperiodic bandlimited electromagnetic fields in lossless nonlinear media, general power-flow relations were derived. They may be regarded as generalisations of the well known relations for sinusoidal fields. For the three signals in parametric devices, inequalities are obtained which determine limiting values for the electromagnetic power densities.     

Energy function and the synthesis of two-variable lossless n-ports

Energy functions may be most profitably employed for deriving basic information about multivariable system functions, their analysis and synthesis. A synthesis of two-variable homogeneous n-ports is given in a concise manner via energy functions. The method is of a fundamental nature which circumvents some of the detailed and complicated existing procedures.     

Model of acoustic interaction between the vocal tract,subglottal region,and vocal source

This study is devoted to constructing a mathematical model of acoustic interaction between the glottal volume velocity, vocal tract, and subglottal region (trachea, bronchi, and lungs). The model is based on the approximation of the acoustic impedances by autoregressive models with a moving mean. The experimental results are in good agreement with the data of other studies on interaction of the vocal source and vocal tract.     

A linear edge model and its application in lossless image coding

A linear edge model for the prediction of edge pixel values is first proposed and a gradient-adjusted predictor based on this model for context-based lossless image coding is then developed. Theoretical analysis and experiment results show that the performance of the proposed predictor is better than that of the state-of-the-art predictors for most test images.     

Towards a high quality Arabic speech synthesis system based on neural networks and residual excited vocal tract model

Text-to-speech conversion has traditionally been performed either by concatenating short samples of speech or by using rule-based systems to convert a phonetic representation of speech into an acoustic representation, which is then converted into speech. This paper describes a text-to-speech synthesis system for modern standard Arabic based on artificial neural networks and residual excited LPC coder. The networks offer a storage-efficient means of synthesis without the need for explicit rule enumeration. These neural networks require large prosodically labeled continuous speech databases in their training stage. As such databases are not available for the Arabic language, we have developed one for this purpose. Thus, we discuss various stages undertaken for this development process. In addition to interpolation capabilities of neural networks, a linear interpolation of the coder parameters is performed to create smooth transitions at segment boundaries. A residual-excited all pole vocal tract model and a prosodic-information synthesizer based on neural networks are also described in this paper.     

Energy flow relations in multiwave systems with absorption and dispersion

Expressions for the time average energy flow are derived for a linear physical system with an arbitrary number of interacting waves. The system is assumed to be temporally and spatially dispersive and to include losses. Waves constant in time but growing or decaying in space with arbitrarily large factors are considered. The results are used to discuss the energy flow components in a traveling-wave tube and in a piezoelectric semiconductor device.     

线性空间隐藏模型下图像无损水印的仿真实验分析

旨在分析线性空间隐藏模型下图像无损水印的仿真实验,提出线性空间隐藏模型下无损水印算法提出。通过将原始图像载体划分为图像块序列,结合整数小波变换,获取待嵌水印子带。在0/1水印序列下,结合线性空间隐藏模型,在图像小波域中嵌入水印,不仅提高了水印的鲁棒性,同时也提高了水印的不可见性。结合简单逆向平移的过程,对原始图像进行恢复。对于线性空间隐藏模型,不仅实验了水印的独立性,同时基于无损水印领域,也提高了水印的鲁棒性,并降低误检率,实现原始图像的无损恢复。线性空间隐藏模型下图像无损水印的仿真实验结果表明,算法的应用不仅可以避免有损压缩,同时也有较好的不可见性和安全性。     

大流量轴快流CO2激光器放电管的对比分析

为了提高大功率轴快流CO2激光器的单根放电管的质量流量,得到更大的单根放电管的输出功率,对原有放电管的喷嘴、绕流环等结构进行了改进和优化,设计出一种新型的大质量流量放电管。采用数值模拟和实验验证的方法对新设计的放电管内的气体流动状态和输出功率进行分析,得到了工作气体的质量流量,放电管的输出功率以及工作气体在放电管内的流场分布,数值模拟结果和实验结果一致,并对不同结构的放电管的输出功率和流场分布进行了比较。结果表明,新设计的放电管的质量流量明显增加,单根放电管的输出功率提高,且能够得到均匀的辉光放电。     

Downlink queuing model and packet scheduling for providing lossless handoff and QoS in AG mobile networks

Next generation mobile networks are expected to provide seamless personal mobile communication and quality-of-service (QoS) guaranteed IP-based multimedia services. Providing seamless communication in mobile networks means that the networks have to be able to provide not only fast but also lossless handoff. This paper presents a two-layer downlink queuing model and a scheduling mechanism for providing lossless handoff and QoS in mobile networks, which exploit IP as a transport technology for transferring datagrams between base stations and the high-speed downlink packet access (HSDPA) at the radio layer. In order to reduce handoff packet dropping rate at the radio layer and packet forwarding rate at the IP layer and provide high system performance, e.g., downlink throughput, scheduling algorithms are performed at both IP and radio layers, which exploit handoff priority scheduling principles and take into account buffer occupancy and channel conditions. Performance results obtained by computer simulation show that, by exploiting the downlink queuing model and scheduling algorithms, the system is able to provide low handoff packet dropping rate, low packet forwarding rate, and high downlink throughput.     

数据流异常检测及其在僵尸网络检测中的应用

目前大多关于P2P僵尸网络检测的研究都采用传统的逆向工程方法,这些方法检测都比较准确,但其工程实施难度太大,效率较低,且对于变种病毒,该类检测方法无能为力。本文尝试通过数据流异常检测技术的应用,找到一种适合数据流应用场景的异常检测方法,并尝试将其应用于P2P僵尸病毒的检测当中,通过监控网络数据流,能够有效地发现P2P僵尸病毒在传播过程当中的特殊行为,并通过捕获这些行为来实现发现僵尸主机的目的。     

Infusion line model for the detection of infiltration,extravasation, and other fluid flow faults

Infiltration or extravasation is the undesirable infusion of fluids and medication into the tissue space surrounding a blood vessel. If left undetected, it may cause severe tissue damage to patients requiring surgical repair or even amputation. While there are numerous patents purporting the automatic detection of infiltration, few seem to be built into current infusion devices, and none are able to distinguish between various faulty fluid flow conditions. An attempt was made to demonstrate that the dynamic hydraulic properties of an IV-line can be used to detect infiltration and extravasation as well as other fluid flow faults such as a kinked line or an occluded needle. A pressure step was applied to five IV-lines under five different experimental conditions; the resulting pressure curves were modeled by a third-order system. With a reliability of 92%, the system parameters were used to detect and correctly identify five different fluid flow conditions     

Prevention of deadlocks and livelocks in lossless backpressured packet networks

No packets will be dropped inside a packet network, even when congestion builds up, if congested nodes send backpressure feedback to neighboring nodes, informing them of unavailability of buffering capacity-stopping them from forwarding more packets until enough buffer becomes available. While there are potential advantages in backpressured networks that do not allow packet dropping, such networks are susceptible to a condition known as deadlock in which throughput of the network or part of the network goes to zero (i.e., no packets are transmitted). In this paper, we describe a simple, lossless method of preventing deadlocks and livelocks in backpressured packet networks. In contrast with prior approaches, our proposed technique does not introduce any packet losses, does not corrupt packet sequence, and does not require any changes to packet headers. It represents a new networking paradigm in which internal network losses are avoided (thereby simplifying the design of other network protocols) and internal network delays are bounded.     

Photovoltaics in grid-connected buildings: Energy flow and economic aspects

Two main subjects must be considered in the analysis of a photovoltaic grid-connected building. the first concerns the various energy flows, such as the hourly photovoltaic generation and the electricity consumption of the building, that determine the global energy balance, i.e. the extent to which the system will be able to supply the building's electricity consumption. This paper provides a simple method to estimate this behaviour. Secondly we must consider the long-term cost of the system, a key aspect that depends on the economic scenario and can be made attractive given the appropriate policies (some examples are mentioned).     

Complex modes in open and shielded lossless planar transmissionlines and their correspondence with leaky modes

The wavenumber of complex modes in lossless planar transmission lines inside a metallic box, with or without top cover, are computed using the transverse resonance method. Without the top cover, some leaky modes can be observed. When these open guiding structures are covered, it is shown that these previous modes generate either evanescent or complex modes, depending on the metallic enclosure position     

Improvements in the model for interoperability of intrusion detection responses compatible with the IDWG model

This paper presents a model for response interoperability between intruder detection systems (IDSs), compatible with the model for alert interoperability developed by the Intrusion Detection Working Group (IDWG). Alterations in IDS IDWG architecture are proposed in order to provide for response interoperability support. The development and testing of the proposed model and its components are also presented. Copyright © 2006 John Wiley & Sons, Ltd.     

磁偶极在各向异性媒质中辐射的能流密度

对各向异性媒质中辐射问题的研究,求出磁偶极在各向异性媒质中辐射的具有张量形式的能流密度的普遍公式,在直角坐标系中,通过并矢计算,得出磁偶极在各向异性媒质中辐射的平均能流密度,并对磁偶极在各向异性媒质中的辐射作出了主要集中方向的判断,为研究各向异性媒质的开发应用提供了一个理论依据.对导出的新公式进行了验证.     

方格网络模型的数据传输动态特性

针对二维方格网络模型,研究了影响网络数据传输效率的3个因素:路由算法、路由器性能和用户策略,并指出3种对应的措施能够提高通信网络的传输效率:根据网络的负载选择不同的网络优化路由算法参数、提高路由器的传输数据的能力以及采用用户反馈策略自调整主机产生数据的概率。     

Contextual encoding in uniform and adaptive mesh-based lossless compression of MR images

We propose and evaluate a number of novel improvements to the mesh-based coding scheme for 3-D brain magnetic resonance images. This includes: 1) elimination of the clinically irrelevant background leading to meshing of only the brain part of the image; 2) content-based (adaptive) mesh generation using spatial edges and optical flow between two consecutive slices; 3) a simple solution for the aperture problem at the edges, where an accurate estimation of motion vectors is not possible; and 4) context-based entropy coding of the residues after motion compensation using affine transformations. We address only lossless coding of the images, and compare the performance of uniform and adaptive mesh-based schemes. The bit rates achieved (about 2 bits per voxel) by these schemes are comparable to those of the state-of-the-art three-dimensional (3-D) wavelet-based schemes. The mesh-based schemes have been shown to be effective for the compression of 3-D brain computed tomography data also. Adaptive mesh-based schemes perform marginally better than the uniform mesh-based methods, at the expense of increased complexity.     

Energy usage analysis of digital modulations in wireless sensor networks with realistic battery model

A wireless sensor network is a collection of tiny sensor nodes that are deployed to monitor a physical environment. These sensor nodes are generally powered by non-renewable batteries and maybe deployed in harsh environment. Thus, energy resource is precious that makes protocols design for this kind of networks a crucial challenge. Especially, in physical layer, orthogonal modulations as PPM or FSK are suitable. The commonly used models to investigate the network lifetime are based on a linear battery discharge. Really, the battery discharge is closely bonded to the discharge current, and typically is non-linear. This paper presents a performance analysis of both PPM and FSK modulations used in battery powered wireless sensor node. A Rakhmatov–Vrudhula–Wallach model is used to evaluate the used battery charge for a given instantaneous current load. By numerical results, it is proved that PPM modulation outperforms FSK one in term of battery charge use for different network density and for different M-ary signaling schemes.