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PERFORMANCE OF NON-COHERENT RECEIVER WITH UWB PPM SIGNAL IN MULTIPATH CHANNELS

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Journal of electronics(China) 2007年第4期24卷 448-454页

作者： Wu Jianjun xiang haige electronics Dept Peking University Beijing100871 China

Mainly due to its implementation simplicity, the non-coherent Ultra-Wide Band (UWB) receiver is attractive for lower data rate applications, which gains much attention again in recent years. In this paper, a General Likelihood Ratio Test (GLRT) based non-coherent receiver on UWB Pulse-Position-Modulation (PPM) signal in multipath channels is derived, and a novel structure is proposed as well. Subsequently, the closed-form expressions of asymptotic error-rate performance related to the non-coherent receiver are also derived and verified.

关键词： Ultra-Wide Band (UWB) Non-coherent General Likelihood Ratio Test (GLRT)

A malware detection model based on a negative selection algorithm with penalty factor

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Science China(Information Sciences) 2010年第12期53卷 2461-2471页

作者： ZHANG PengTao 1,2., WANG Wei 1,2.& TAN Ying 1,2.1 {3. of Machine Intelligence, School of electronics Engineering and Computer Science,{2., Beijing {3., China 2.Key Laboratory of Machine Perception, Ministry of Education,{2., Beijing {3., China 1. department of Machine Intelligence School of Electronics Engineering and Computer Science Peking University Beijing 100871 China2. Key Laboratory of Machine Perception Ministry of Education Peking University Beijing 100871 China

A malware detection model based on a negative selection algorithm with penalty factor (NSAPF) is proposed in this paper. This model extracts a malware instruction library (MIL), containing instructions that tend to appear in malware, through deep instruction analysis with respect to instruction frequency and file frequency. From the MIL, the proposed model creates a malware candidate signature library (MCSL) and a benign program malware-like signature library (BPMSL) by splitting programs orderly into various short bit strings. Depending on whether a signature matches "self", the NSAPF further divides the MCSL into two malware detection signature libraries (MDSL1 and MDSL2., and uses these as a two-dimensional reference for detecting suspicious programs. The model classifies suspicious programs as malware and benign programs by matching values of the suspicious programs with MDSL1 and MDSL2. Introduction of a penalty factor C in the negative selection algorithm enables this model to overcome the drawback of traditional negative selection algorithms in defining the harmfulness of "self" and "nonself", and focus on the harmfulness of the code, thus greatly improving the effectiveness of the model and also enabling the model to satisfy the different requirements of users in terms of true positive and false positive rates. Experimental results confirm that the proposed model achieves a better true positive rate on completely unknown malware and a better generalization ability while keeping a low false positive rate. The model can balance and adjust the true positive and false positive rates by adjusting the penalty factor C to achieve better performance.

关键词： penalty factor negative selection algorithm signature extraction artificial immune system mal- ware detection

A new method for adaptive color image filtering

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Chinese Science Bulletin 2000年第13期45卷 1230-1235页

作者： JIANG Gangyi, YU Mei & YU Bokang1. department, of Information & Electronic Engineering, Hang/hou university of Commerce, Hangzhou 3.003., China 2. department, of Electronic Engineering, Hangzhou institute of {3. Engineering, Hangzhou 3.003., China 3. State Key Laboratory on Machine Perception, peking university, Beijing 100871, China Correspondence should be addressed to Yu Mei department of Information & Electronic Engineering Hangzhou University of Commerce Hangzhou China State Key Laboratory on Machine Perception Peking University Beijing China department of Electronic Engineering Hangzhou Institute of Electronics Engineering Hangzhou China

An adaptive color image filter (ACIF) is proposed in this note. Through analyzing noise corruption of color image, efficient locally adaptive filters are chosen for image enhancement. The proposed adaptive color image filter combines advantages of both nonlinear vector filters and linear filters, it attenuates noise and preserves edges and details very well. Experimental results show that the proposed filter performs better than vector median filter, directional-distance filter, directional-magnitude vector filter, adaptive nearest-neighbor filter, and α-trimmed mean filter.

关键词： color image noise analysis locally adaptive filters adaptive color image filter (ACIF).

Fabrication of multi-sectional TiO_2.nanotube arrays by anodization

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Science China Chemistry 2010年第5期53卷 1067-1072页

作者： LI ShiQi,YIN JianBo & ZHANG GengMin Key Laboratory for the Physics and Chemistry of Nanodevices and department of electronics,{2.{3.,Beijing 100871,China 1. Key Laboratory for the Physics and Chemistry of Nanodevices and department of electronics Peking University Beijing 100871 China

We report a facile method to grow multi-sectional TiO2.nanotube arrays consisting of alternating bamboo-shaped and smooth-walled nanotube sections by *** key factors are necessary for obtaining these ***,in order to avoid possible disruptions between the conjoint sections of the nanotube,the distribution of hydrogen ions is suggested not to be fiercely disturbed when switching from the first to the second ***,to avoid the disruption of the nanotube at the joint which results from the disparity in diameters between sections,the direct current voltage is set to be the maximum of the square wave *** newly developed TiO2.nanotube arrays are expected to have potential applications in solar cells,drug release and delivery systems.

关键词： titanium dioxide titania nanotube anodic oxidation

Technical framework for Internetware: An architecture centric approach

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Science in China(Series F) 2008年第6期51卷 610-622页

作者： YANG FuQing1,2. Lü Jian3.4 & MEI Hong1,2.1 Key Laboratory of High Confidence Software Technologies (peking {3.), Ministry of Education, Beijing {2., China 2.School of {3. Engineering and Computer Science, peking university, Beijing {2., China 3.State Key Laboratory for Novel Software Technology, Nanjing 2.0093. China 4 department of Computer Science and Technology, Nanjing {3., Nanjing 2.0093. China 1. Key Laboratory of High Confidence Software Technologies (peking university) Ministry of Education Beijing 100871 China 2. School of electronics Engineering and Computer Science Peking University Beijing 100871 China 3. State Key Laboratory for Novel Software Technology Nanjing 210093 China 4. department of Computer Science and Technology Nanjing University Nanjing 210093 China

Being a new software paradigm evolved by the Internet, Internetware brings many challenges to the traditional software methods and techniques. Sponsored by the national basic research program （973., researchers in China have developed an architecture centric technical framework for the definition, incarnation and engineering of Internetware. First of all, a software model for Internetware is defined for what to be, including that Internetware entities should be packaged as components, behaving as agents, interoperating as services, collaborating in a structured and on demand manner, etc. Secondly, a middleware for Internetware is designed and implemented for how to be, including that Internetware entities are incarnated by runtime containers, structured collaborations are enabled by runtime software architecture, Internetware can be managed in a reflective and autonomic manner, etc. Thirdly, an engineering methodology for Internetware is proposed for how to do, including the way to develop Internetware entities and their collaborations by transforming and refining a set of software architectures which cover all the phases of software lifecycle, the way to identify and organize the disordered software assets by domain modeling, etc.

关键词： Internetware component software architecture agent middleware

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原子的交流塞曼效应(英文)

北京大学学报（自然科学版） 1999年第1期35卷 125-129页

作者： XING Aitang (department of electronics,{2.{3.,Beijing,100871) 北京大学电子学系北京100871

用一种简单的半经典方法推导出了交流塞曼效应中的能级移动公式。从这一公式得到的结果与实验中观察到的现象是一致的，而且从理论上预言了交流塞曼效应的２个重要性质：原子交流塞曼效应中的能级移动是与跃迁同时发生的瞬态过程；能级... 详细信息

用一种简单的半经典方法推导出了交流塞曼效应中的能级移动公式。从这一公式得到的结果与实验中观察到的现象是一致的，而且从理论上预言了交流塞曼效应的２个重要性质：原子交流塞曼效应中的能级移动是与跃迁同时发生的瞬态过程；能级移动具有饱和性。

关键词：交流塞曼效应能级移动公式二能级原子原子

APPLYING OONN TO SOLVE MAP-COLORING PROBLEM

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Journal of electronics(China) 1993年第1期10卷 9-14页

作者：余道衡贾积有 department of Radio and electronics Peking UniversityBeijing 100871

For solving the map-coloring problems,this paper presents an energy function,amore effective dynamic equation and a more simple convergence *** the first time westudy the map-coloring problems in the way of connecting discrete Hopfield neural network withthe orthogonal optimization,and as a practical example,a color map of China is given.

关键词： Map-coloring problem Hopfield neural network Orthogonal optimization

Laplacian smoothing transform for face recognition

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Science China(Information Sciences) 2010年第12期53卷 2415-2428页

作者： GU SuiCheng, TAN Ying & HE XinGui Key Laboratory of Machine Perception (MOE) department of Machine Intelligence, School of electronics Engineering and Computer Science {2.{3., Beijing 100871, China 1. Key Laboratory of Machine Perception (MOE) department of Machine Intelligence School of Electronics Engineering and Computer Science Peking University Beijing 100871 China

In this paper, we investigate how to extract the lowest frequency features from an image. A novel Laplacian smoothing transform (LST) is proposed to transform an image into a sequence, by which low frequency features of an image can be easily extracted for a discriminant learning method for face recognition. Generally, the LST is able to be an efficient dimensionality reduction method for face recognition problems. Extensive experimental results show that the LST method performs better than other pre-processing methods, such as discrete cosine transform (DCT), principal component analysis (PCA) and discrete wavelet transform (DWT), on ORL, Yale and PIE face databases. Under the leave one out strategy, the best performance on the ORL and Yale face databases is 99.75% and 99.4%; however, in this paper, we improve both to 100% with a fast linear feature extraction method for the first time.

关键词： Laplacian smoothing transform (LST) face recognition principal component analysis (PCA) discrete cosine transform (DCT) discrete wavelet transform (DWT) linear discriminant analysis (LDA)

A low power and small area all digital delay-locked loop based on ring oscillator architecture

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Science China(Information Sciences) 2012年第2期55卷 453-460页

作者： ZHENG JiaPeng1,LI Wei2.LU XueQing2.CHENG YuHua1 & WANG YangYuan1 1department of Micro{3.,School of {3. Engineering and Computer Science,peking university,Beijing 100871,China 2.emiconductor Manufacturing International Corp,Shanghai 2.12.3.China 1. department of Microelectronics School of Electronics Engineering and Computer Science Peking University Beijing 100871 China2. Semiconductor Manufacturing International Corp Shanghai 201203 China

A 13.-500 MHz,5.2.mW @500 MHz,0.02. mm2.all digital delay-locked loop(ADDLL)is *** power and area reduction of the proposed ADDLL are achieved by implementing a high frequency ring oscillator(ROSC)to count the reference clocks such that the one-clock cycle delay chain and the phase detector in a conventional Master block are no longer *** proposed ADDLL has better immunity to PVT(process,voltage,and temperature)than most conventional DLLs,which do not update the control word signals after the locking process,since the control signals for slave delay line are updated in every 2.6 reference *** in 0.13.um CMOS process,the measured RMS jitter is 10.83.ps at 500 MHz while the RMS jitter of the input signal is 9.97 ps.

关键词： all digital delay locked loop(DLL) phase locked loop(PLL) ring oscillator