Automatic computation of histogram threshold for lip segmentation using feedback of shape information

Threshold-based segmentation methods provide a simple and efficient way to implement lip segmentation. However, automatic computation of robust thresholds presents a major challenge. This research proposes an adaptive method for selecting the histogram threshold, based on feedback of shape information. The proposed method reduces unnecessary overhead by first comparing the initial segmentation to a reference lip shape model to decide if optimisation is required. In cases where optimisation is required, the algorithm adjusts the threshold until the segmentation is sufficiently similar to a reference shape model. The algorithm is tested on the AR Face Database by comparing the segmentation accuracy before and after optimisation. The proposed method increases the number of segmentations classified as ‘good’ (overlap above 90 %) by 7.1 % absolute, and significantly improves the segmentation in challenging cases containing facial hair.     

Hybrid image steganography method using Lempel Ziv Welch and genetic algorithms for hiding confidential data

Multidimensional Systems and Signal Processing - Digital images are commonly used in steganography due to the popularity of digital image transfer and exchange through the Internet. However, the...     

面对高亮度LED设计的挑战

现在全球各地已逐渐淘汰传统的白炽灯泡.不仅政府机构,连民间使用者也要求更高效率的照明解决方案.精致型荧光灯泡(CFL)并非解决此项问题的最佳方案.     

Locating the optic nerve in a retinal image using the fuzzy convergence of the blood vessels

We describe an automated method to locate the optic nerve in images of the ocular fundus. Our method uses a novel algorithm we call fuzzy convergence to determine the origination of the blood vessel network. We evaluate our method using 31 images of healthy retinas and 50 images of diseased retinas, containing such diverse symptoms as tortuous vessels, choroidal neovascularization, and hemorrhages that completely obscure the actual nerve. On this difficult data set, our method achieved 89% correct detection. We also compare our method against three simpler methods, demonstrating the performance improvement. All our images and data are freely available for other researchers to use in evaluating related methods.     

Globalization and heterogenization: Cultural and civilizational clustering in telecommunicative space (1989–1999)

The globalization of telecommunicative ties between nations is studied from a heterogenization perspective. A theoretical model inspired by Appadurai’s “disjuncture hypothesis,” which stipulates that global flows of communication are multidimensional and reinforce regional/local identities, is tested empirically on an international voice traffic dataset. Spatial-statistical measures (global and local versions of Moran’s I) indicate that countries that share the same linguistic (English, Spanish, or French) or civilizational (Catholic, Protestant, and Buddhist–Hindu) background are more likely to be each other’s “telecommunicative neighbors” and that this tendency has increased over time (1989–1999).     

Blind deconvolution of ultrasound sequences using nonparametric local polynomial estimates of the pulse

The problem of reconstructing the reflectivity of a biological tissue is examined by means of blind deconvolution of the echo ultrasound signals. It is shown that the quality of the reconstruction procedure can be significantly improved when initially the ultrasonic pulse is accurately estimated. A new approach to the estimation of the ultrasound pulse echo sequences is proposed, using local polynomial approximation, which is closely related to the wavelet transform theory. This approach can be viewed as a modification of homomorphic deconvolution, by using bases different from the Fourier basis of the space of square-integrable functions L2. The bases used here are the orthogonal compactly supported wavelet bases. It is shown that the locality of the estimate can be extremely useful in number of cases of practical interest, resulting in estimates with smaller root-mean squared (rms) errors, as compared with estimates employing the Fourier basis. This approach is applied to ultrasound signals, for estimation of the ultrasound pulse log-spectrum from the log-spectrum of radio-frequency (RF) sequences. It is shown, conceptually and experimentally, that the proposed approach can provide robust and rapidly computed estimates of the ultrasound pulses from the RF-sequences, as obtained in the process of tissue scanning. The pulse phase was recovered using the minimum-phase assumption, which was found to hold for the transducers in use. The obtained pulse estimates are used for the deconvolution of the RF-sequences, which result in stable estimates of the tissue reflectivity function, fairly independent of the properties of the imaging system. Simulated data, data obtained from several phantoms and from in vitro experiments have been processed and the results seem to be quite promising.     

下一代手机设计的集成技术

为了满足对于高度集成的无线电半导体解决方案日益增长的需求，蜂窝电话的技术创新正在沿着两个不同的方向发展。其一是在芯片级和封装级的功能集成，其二是完整的半导体系统解决方案。后者将所有必须的芯片、模块和软件捆绑到一个全面的解决方案中，从而简化了设计步骤．加快了产品进入市场的时间。     

能实现高压输出的抽头电感升压稳压器

当您面对产生比可用电源电压更高的稳定电压任务时,可以考虑升压稳压器。虽然升压转换器在理论上能产生比其输入更高的几乎任何电压,但实际的考虑把输出限制为对其施加的电压的大约8倍。为了产生更高的电压,可考虑使用抽头电感升压拓扑结构。图1展示了某种转换器的实现,它把3V输入提高到了100Vdc。稳压器芯片的连接类似于传统升压转换器的连接,但为了达到很高的升压比,该设计使用了L1,即一个1:6匝数比的抽头电感。图2中的波形示出了输入电压、电源开关IC1输出端(5号引脚SW)的电压、整流二极管D1的阳极电压。如同任何升压电路一样,当IC1…     

A Patterned 3D Silicon Anode Fabricated by Electrodeposition on a Virus‐Structured Current Collector

Electrochemical methods were developed for the deposition of nanosilicon onto a 3D virus‐structured nickel current collector. This nickel current collector is composed of self‐assembled nanowire‐like rods of genetically modified tobacco mosaic virus (TMV1cys), chemically coated in nickel to create a complex high surface area conductive substrate. The electrochemically depo­sited 3D silicon anodes demonstrate outstanding rate performance, cycling stability, and rate capability. Electrodeposition thus provides a unique means of fabricating silicon anode materials on complex substrates at low cost.