A Multi-component Matrix Loop Algebra and Its Application

A set of multi-component matrix Lie algebra is constructed. It follows that a type of new loop algebra A^- M-1 is presented. An isospectral problem is established. Integrable multi-component hierarchy is obtained by Tu pattern, which possesses tri-Hamiltonian structures. Furthermore, it can be reduced to the well-known AKNS hierarchy and BPT hierarchy. Therefore, the major result of this paper can be regarded as a unified expression integrable model of the AKNS hierarchy and the BPT hierarchy.     

关于环网G（N;S1,S2）的直径

本文首先给出了环网G(N;s_1,s_2)存在有限直径的充要条件;用初等数论方法给出了其直径的简明计算公式;最后讨论了类似文献[3]的环网直径的对偶性问题.     

基于锁相同步检测的数字化阻抗测试方法

介绍了一种数字化阻抗测试方法，它采用锁相同步采样、数字化矢量电压电流比法及校准技术测试元器件或线路阻抗。同时介绍了相应实验电路原理，并结合线路接口，进行了通信电缆的线路阻抗测试实验。     

一种新颖的跳频振荡器

摘要本文综合考虑到频率合成技术及单端口体波谐振器HBAR的特点提出了一种基于一阶非线性PLL的锁相频率合成方案。文中对这种跳频方案的原理、性能特点作了详细论述、并通过实验、从不同角度对本方案进行了说明、同时对整机的各项指标作了详尽测试:在HBAR无载Q_N值为4000的情况下,该多模跳频振荡源的捷变范围为770MHz—840MHz、捷变时间小于20μS。杂散分量低于—60dB、二次谐波分量低于—34dB。离散捷变频率点为16点,构成闭环跳频系统后,对开环VCO的短稳改善了三个量级:从1.3×10~(-5)/ms到1.6×10~(-8)/ms及9.56×~(-7)/s到1.69×!0~(-9)/s,尤为重要的是该多模跳频振荡源达到此性能所需的硬件量很小,因此在对体积要求苛刻的场合、此种跳频方案具有极强的竞争力。     

Learning a Deep Metric: A Lightweight Relation Network for Loop Closure in Complex Industrial Scenarios

The similarity metric in Loop closure detection (LCD) is still considered in an old fashioned way, i.e. to pre-define a fixed distance function, leading to a limited performance. This paper proposes a general framework named LRN-LCD, i.e. a Lightweight relation network for LCD, which combines the feature extraction module and similarity metric module into a simple and lightweight network. The LRN-LCD, an end-to-end framework, can learn a non-linear deep similarity metric to detect loop closures from different scenes. Moreover, the LRN-LCD supports image sequences as input to speed up the similarity metric in real-time applications. Extensive experiments on several open datasets illustrate that LRN-LCD is more robust to strong condition variations and viewpoint variations than the mainstream methods.     

Algebraic structure in the loop space homology Bockstein spectral sequence

Let be a finite, -dimensional, -connected CW complex. We prove the following theorem:

If is an odd prime, then the loop space homology Bockstein spectral sequence modulo is a spectral sequence of universal enveloping algebras over differential graded Lie algebras.

     

ESR spectrometer with a loop-gap resonator for cw and time resolved studies in a superconducting magnet

The design and performance of an electron spin resonance spectrometer operating at 3 and 9 GHz microwave frequencies combined with a 9-T superconducting magnet are described. The probehead contains a compact two-loop, one gap resonator, and is inside the variable temperature insert of the magnet enabling measurements in the 0-9T magnetic field and 1.5-400 K temperature range. The spectrometer allows studies on systems where resonance occurs at fields far above the g approximately 2 paramagnetic condition such as in antiferromagnets. The low quality factor of the resonator allows time resolved experiments such as, e.g., longitudinally detected ESR. We demonstrate the performance of the spectrometer on the NaNiO2 antiferromagnet, the MgB2 superconductor, and the RbC60 conducting alkaline fulleride polymer.     

Anick's spaces and the double loops of odd primary Moore spaces

Several properties of Anick's spaces are established which give a retraction of Anick's off if and . The proof is alternate to and more immediate than the two proofs of Neisendorfer's.

     

AWG and EDFA based optical packet switch using feedback shared loop buffer memory

Optical packet switching provides high speed, data rate/format transparency, efficient use of bandwidth and flexibility. The major problem in the implementation of “all-optical” switching is contention which occurs when two or more packets arrive at the same time for the same destination. To resolve the contention, we have proposed an optical packet switch architecture based on WDM loop buffer memory in the feedback configuration. In that architecture, the contending packets are stored in a loop buffer module, and routed in the free time slots. The buffering duration in the recirculating loop is limited by a circulation limit. The analysis was been done to obtain the maximum number of allowed circulations. This paper proposes improved version of that optical packet switch architecture, to increase the number of maximum allowed circulations. The modification is done either by adding an extra erbium doped fiber amplifier (EDFA) in the original switch or by replacing the core space switch with arrayed waveguide grating (AWG). The performance analysis has been done by the simulations.     

Equivalent Model, Error Analysis, and Design Steps of AGC Loop for MM-Wave Receiver

Automatic Gain Controlled (AGC) Loops are used in MM-Wave receiver in wide-ranging. In this paper, the equivalent model and loop equation of AGC Loop are built, the loop errors are analyzed and then the design steps of AGC Loop are given out.