QUANTUM MECHANICAL MODEL AND SIMULATION OF GaAs／AlGaAs QUANTUM WELL INFRARED PHOTODETECTOR—Ⅱ ELECTRICAL ASPECTS

ＩｎｔｒｏｄｕｃｔｄｏｎＩｎｔｈｅｆｉｒｓｔｐａｒｔ ,ｗｅｈａｖｅｄｉｓｃｕｓｓｅｄｔｈｅｏｐｉｔｉｃａｌａｓｐｅｃｔｓａｂｏｕｔｔｈｅｑｕａｎｔｕｍｗｅｌｌｉｎｆｒａｒｅｄｐｈｏｔｏｄｅｔｅｃ ｔｏｒ .Ｈｅｒｅｗｅｃｏｎｔｉｎｕｅｄｉｓｃｕｓｓｉｏｎｓａｂｏｕｔｔｈｅｅｌｅｃｔｒｉｃａｌａｓｐｅｃｔｅｓｏｆｔｈｅｄｅｖｉｃｅｍｏｄｅｌａｎｄｓｉｍｕｌａｔｉｏｎ .1　ＤａｒｋＣｕｒｒｅｎｔａｎｄＰｈｏｔｏｃｕｒｒｅｎｔＤｉｓｔｒｉｂｕｔｅｄｅｆｆｅｃｔｓｏｆｅｘｔｅｒｎａｌｂｉａｓａｃｒｏｓｓｔｈ…     

Editorial Personal,Mobile Radio and Spread Spectrum Communications

ＥｄｉｔｏｒｉａｌＰｅｒｓｏｎａｌ，ＭｏｂｉｌｅＲａｄｉｏａｎｄＳｐｒｅａｄＳｐｅｃｔｒｕｍＣｏｍｍｕｎｉｃａｔｉｏｎｓＺｈｏｕＪｉｏｎｇｐａｎ；ＣｈｅｎｇＲｕｍｉｎｇ（ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＰｏｓｔｓａｎｄＴｅｌｅｃｏｍｍｕｎｉｃａ...     

The Classification of Degrees at the Level of Needs

1　ＲｅｖｉｅｗｏｆＮｅｅｄｓＴｈｅｏｒｙＮｅｅｄｓｄｅｒｉｖｅｄｆｒｏｍｃｏｎｃｒｅｔｅｉｎｄｉｖｉｄｕａｌｎｅｃｅｓｓｉ ｔｙｃａｎｂｅｄｉｖｉｄｅｄｉｎｔｏｄｉｆｆｅｒｅｎｔａｓｐｅｃｔｓａｓｍａｔｅｒｉａｌ,ｍｅｎｔａｌｉｔｙ,ｍｏｒａｌｉｔｙａｎｄｃｕｌｔｕｒｅ .Ａｎｄｔｈｅｓｅａｒｅａｌｌｅｓｔａｂｌｉｓｈｅｄｏｎｔｈｅｂａｓｉｓｏｆｔｈｅｄｅｖｅｌｏｐｍｅｎｔｃｏｕｒｓｅｏｆｍｏｄｅｒｎｃｉｖｉｌｉｚａｔｉｏｎ .ＡｃｃｏｒｄｉｎｇｔｏＭ .Ｈ .Ｍａｓｌｏｗ ,ｂｅｈａｖｉｏｒｉｓｐｒｏｄｕ…     

掩模缺陷规范造成的器件成品率和可靠性问题

掩模缺陷规范造成的器件成品率和可靠性问题＝Ｄｅｖｉｃｅｙｉｅｌｄａｎｄｒｅｌｉａｂｉｌｉｔｙｂｙ．ｓｐｅｃｉｆｉｃａ－ｔｉｏｎｏｆｍａｓｋｄｅｆｅｃｔｓ［刊，英］／Ｗｉｌｅｙ，Ｊ．Ｎ…／／ＳｏｌｉｄＳｔａｔｅＴｅｃｈｎｏｌ．－１９９３．３６（７）．－...     

Raman Spectra of AlP/GaP Short-period Superlatice

１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｌａｔｉｃｅｄｙｎａｍｉｃｓｏｆｓｅｍｉｃｏｎｄｕｃｔｏｒｓｕｐｅｒｌａｔｉｃｅｈａｓｂｅｅｎｅｘｔｅｎｓｉｖｅｌｙｓｔｕｄｉｅｄ［１，２］．ＴｈｅＲａｍａｎｓｐｅｃｔｒａｏｆＡｌＡｓ／ＧａＡｓ，ＧａＡｌＡｓ／ＧａＡｓ...     

最新颁布广播电影电视行业标准简介

现将经国家广播电影电视总局批准颁布的６项行业标准的内容和适用范围简介如下：　　　　１、ＧＹ　Ｔ１６８－２００１《广播音频数据文件格式规范──广播波形格式（ＢＷＦ）》　　　　Ｓｐｅｃｉｆｉｃａｔｉｏｎ　ｏｆ　ｔｈｅ　ｆｏｒｍａｔ　ｆｏｒ　ａｕｄｉｏ　ｄａｔａ　ｆｉｌｅｓ　ｉｎ　ｂｒｏａｄｃａｓｔｉｎｇ──Ｔｈｅ　ｂｒｏａｄｃａｓｔ　ｗａｖｅ　ｆｏｒｍａｔ（ＢＷＦ）　　　　本标准适用范围：　　　　本标准规定了一种专业广播领域内的数字音频文件格式和技术要求。　　　　本标准适用于采用数字音频线性ＰＣＭ和…     

数字电视出现新图景

一家叫Ｇｅｏｃａｓｔ的新兴网络系统公司希望通过他们的产品能为电视台提供最终的数字电视解决方案。Ｇｅｏｃａｓｔ公司开发了一种新的技术可以超高速地传输数据。通过无线电波传输的高清晰度数字电视（ＨＤＴＶ）信号会被发送到Ｇｅｏｃａｓｔ公司开发的一个相关设备中,并被储存在这个设备的大容量存储器内。Ｇｅｏｃａｓｔ公司说这样的一个设备价格不会超过３００美金,Ｇｅｏｃａｓｔ的新技术同样离不开用以发送信息的常规Ｉｎｔｅｒｎｅｔ连接。如果这种设备能象Ｇｅｏｃａｓｔ预期的那样于２０００年底面市的话,它将会大大地加块…     

Multicast在Internet上的实现

本文介绍了Ｉｎｔｅｒｎｅｔ上的一种新的数据传输方式－－Ｍｕｌｔｉｃａｓｔ，着重阐述了Ｍｕｌｔｉｃａｓｔ在ＴＣＰ／ＩＰ各层的实现，包括各种新的协议和应用等，最后简要介绍了Ｍｕｌｔｉｃａｓｔ技术的发展动向。     

A Novel Low-bit-rate Speech Coding Based on Decomposition of the Pitch-cycle Waveform of the Linear Predictive Residual

ＡＮｏｖｅｌＬｏｗｂｉｔｒａｔｅＳｐｅｃｈＣｏｄｉｎｇＢａｓｅｄｏｎＤｅｃｏｍｐｏｓｉｔｉｏｎｏｆｔｈｅＰｉｔｃｈｃｙｃｌｅＷａｖｅｆｏｒｍｏｆｔｈｅＬｉｎｅａｒＰｒｅｄｉｃｔｉｖｅＲｅｓｉｄｕａｌＢａｏＣｈａｎｇｃｈｕｎ（Ｄｅｐａｒｔｍ...     

Combinatory Spread－Spectrum Multiple－Access Based on Residue Number System：System and Performance

ＣｏｍｂｉｎａｔｏｒｙＳｐｒｅａｄ－ＳｐｅｃｔｒｕｍＭｕｌｔｉｐｌｅ－ＡｃｃｅｓｓＢａｓｅｄｏｎＲｅｓｉｄｕｅＮｕｍｂｅｒＳｙｓｔｅｍ：ＳｙｓｔｅｍａｎｄＰｅｒｆｏｒｍａｎｃｅＹａｎｇＬｉｅｌｉａｎｇ；ＬｉＣｈｅｎｇｓｈｕ（ＮｏｒｔｈｅｒｎＪｉａｏｔ...     

3-d object retrieval and recognition with hypergraph analysis

View-based 3-D object retrieval and recognition has become popular in practice, e.g., in computer aided design. It is difficult to precisely estimate the distance between two objects represented by multiple views. Thus, current view-based 3-D object retrieval and recognition methods may not perform well. In this paper, we propose a hypergraph analysis approach to address this problem by avoiding the estimation of the distance between objects. In particular, we construct multiple hypergraphs for a set of 3-D objects based on their 2-D views. In these hypergraphs, each vertex is an object, and each edge is a cluster of views. Therefore, an edge connects multiple vertices. We define the weight of each edge based on the similarities between any two views within the cluster. Retrieval and recognition are performed based on the hypergraphs. Therefore, our method can explore the higher order relationship among objects and does not use the distance between objects. We conduct experiments on the National Taiwan University 3-D model dataset and the ETH 3-D object collection. Experimental results demonstrate the effectiveness of the proposed method by comparing with the state-of-the-art methods.     

Three-dimensional visualization of partially occluded objects using integral imaging

A three-dimensional (3-D) scene may contain foreground objects which partially occlude background objects. In this paper, we present experiments on reconstruction of the unobstructed view of the background objects from a partially occluded 3-D scene using an integral imaging system. We have reconstructed images of the scene at various distances of interest through computational and optical integral imaging reconstruction in order to obtain images of the occluding foreground objects and partially occluded background objects.     

Urban object reconstruction using airborne laser elevation image and aerial image

Creating three-dimensional (3-D) models of real urban objects is an important goal in a wide variety of applications. This paper describes a method that utilizes airborne laser elevation images and aerial images for the 3-D reconstruction of urban objects. Our modeling approach uses the vertical geometric pattern analysis of elevation images. These patterns correspond to object contours and, thus, enable the extraction of the object. In addition, to provide realistic textured details, textures are cut from aerial images and mapped onto 3-D models. Our texture-mapping approach can avoid geometry mismatching and enable the automatic registration to determine the most reliable correspondence between projected outlines of 3-D models and contours of real objects shown in aerial images. Edge pairs, which are matched with projected outlines, are detected from aerial images. In order to minimize mismatching, we apply the voting technique based on the generalized Hough transform. Experimental results show that 3-D reconstruction of urban objects is generally successful.     

A novel 5-D depth–velocity filter for enhancing noisy light field videos

A 5-D depth–velocity filter is proposed for enhancing moving objects in noisy light field videos (LFVs) (also known as plenoptic videos). The proposed filter consists of an ultra-low complexity 5-D IIR depth filter and a 5-D FIR velocity filter. The 5-D IIR depth filter is employed to denoise a noisy LFV. The denoised LFV is then utilized to estimate the 3-D apparent velocity of the moving object of interest. The 5-D FIR velocity filter is designed based on the estimated 3-D apparent velocity and is used to enhance the moving object of interest while attenuating other interfering moving objects. Experimental results confirm the effectiveness of the proposed 5-D depth–velocity filter compared to previously reported 5-D depth–velocity filters.     

Validation of 3-D curved objects: CAD model and fabricatedworkpiece

This paper proposes a new method to describe and identify a 3-D curved object for the purpose of validating a fabricated object to the design specification. Curved 3-D objects are, in general, difficult to represent and identify because they lack distinct properties such as edges, planes, or cylindrical surfaces which are the building blocks in representing objects. In this paper, the authors propose to use principal axes of a 3-D object to establish a reference for the representation. A method of obtaining an inertia matrix from a 3-D range image is developed. The unique set of principal axes is obtained from the inertia matrix of an object with an arbitrary 3-D position and orientation, and the object can be described uniquely on these principal axes. On the principal axes, an object is described by a set of features describing the shape of the object such as spine, section size, section orientation, and section contraction. The features are used for comparing two objects for the validation purpose. The authors also propose a direct measure of similarity between two objects as a mean-squared difference of radii. As an experiment, two 3-D object models are designed through a CAD package, and fabricated objects are compared with the designed models for validation purposes     

Joint source and channel coding for 3-D scene databases using vector quantization and embedded parity objects.

Three-dimensional graphic scenes contain various mesh objects in one geometric space where different objects have potentially unequal importance regarding display. This paper proposes an object-oriented system for efficiently coding and streaming 3-D scene databases in lossy and rate-constrained environments. Vector quantization (VQ) is exploited to code 3-D scene databases into multiresolution hierarchies. For the best distortion-rate performance, adaptive quantization precisions are allocated to different objects and different layers of each object based on a weighted distortion model. Upon transmission, scalably coded objects are delivered in respective packet sequences to preserve their manipulation independency. For packet loss resilience, a plurality of FEC codes are generated as "parity objects" parallel to graphic objects, which protect the graphic objects concurrently and also preferentially in regard to their unequal decoding importance. A rate-distortion optimization framework is then developed, which performs rate allocation between graphic objects and parity objects and generates the parity data properly. We show that, by treating graphic objects jointly and preferentially in source and channel coding while preserving their independencies in transport, the proposed system reduces the receiving distortion of the 3-D database significantly compared to conventional methods.     

无狭缝彩虹全息术假彩色编码

采用无狭缝彩虹全息术对三维漫射体进行假彩色编码。记录三维漫射体的不同部位时,参考光处于不同的方向,同时将物体均匀平移。全息图在白光再现时,就出现不同颜色,文中给出理论分析和实验结果。     

Exact reduced-complexity maximum likelihood reconstruction of multiple 3-D objects from unlabeled unoriented 2-D projections and electron microscopy of viruses.

In cryo-electron microscopy, the data is comprised of noisy 2-D projection images of the 3-D electron scattering intensity of the object where the orientation of the projections is unknown. Often, the images show randomly selected objects from a mixture of different types of objects. Objects of different type may be unrelated, e.g., different species of virus, or related, e.g., different conformations of the same species of virus. Due to the low SNR and the 2-D nature of the data, it is challenging to determine the type of the object shown in an individual image. A statistical model and maximum likelihood estimator that computes simultaneous 3-D reconstruction and labels using an expectation maximization algorithm exists but requires extensive computation due to the numerical evaluation of 3-D or 5-D integrations of a square matrix of dimension equal to the number of degrees of freedom in the 3-D reconstruction. By exploiting the geometry of rotations in 3-D, the estimation problem can be transformed so that the inner-most numerical integral has a scalar rather than a matrix integrand. This leads to a dramatic reduction in computation, especially as the number of degrees of freedom in the 3-D reconstruction increases. Numerical examples of the 3-D reconstructions are provided based on synthetic and experimental images where the objects are small spherical viruses.     

Two-dimensional mesh-based visual-object representation forinteractive synthetic/natural digital video

This paper first provides an overview of two-dimensional (2-D) and three-dimensional mesh models for digital video processing. It then introduces 2-D mesh-based modeling of video objects as a compact representation of motion and shape for interactive, synthetic/natural video manipulation, compression, and indexing. The 2-D mesh representation and the mesh geometry and motion compression have been included in the visual tools of the upcoming MPEG-4 standard. Functionalities enabled by 2-D mesh-based visual-object representation include animation of still texture maps, transfiguration of video overlays, video morphing, and shape-and motion-based retrieval of video objects