ITER CC导体测试装置数据采集系统的设计与应用

系统介绍了ITER CC性能认证超导导体测试装置数据采集系统的硬件设计。该系统可以对温度、压力、流量、液位、电流、磁场、电阻、电压降等物理量进行测量,并能根据实际需要进行系统扩展。另外还对基于VC++6.0编程环境下的数据采集系统的程序设计进行了介绍。通过对软件和硬件的集成调试,该系统实现了高速高精度的数据采集。     

基于LabVIEW实现的多光谱激光雷达数据采集与处理系统

针对激光雷达在物性信息探测方面的缺陷,提出了一种新型多光谱激光雷达用于地物探测,兼具三维空间探测能力和物性探测能力。随着探测波长增加,多光谱激光雷达数据采集与处理对整个系统的运行至关重要。根据多光谱激光雷达系统结构原理,基于图形化编程语言Lab-VIEW,进行数据采集与处理系统单元及整体设计,实现系统功能需求。通过实验运行,数据采集与处理系统的运行良好,同时多通道回波信号的采集也进一步验证了多光谱激光雷达的物性探测能力。     

Fused-MCP With Application to Signal Processing

ABSTRACT

Friedman et al. proposed the fused lasso signal approximator (FLSA) to denoise piecewise constant signals by penalizing the ?₁ differences between adjacent signal points. In this article, we propose a new method, referred to as the fused-MCP, by combining the minimax concave penalty (MCP) with the fusion penalty. The fused-MCP performs better than the FLSA in maintaining the profile of the original signal and preserving the edge structure. We show that, with a high probability, the fused-MCP selects the right change-points and has the oracle property, unlike the FLSA. We further show that the fused-MCP achieves the same l₂ error rate as the FLSA. We develop algorithms to solve fused-MCP problems, either by transforming them into MCP regression problems or by using an adjusted majorization-minimization algorithm. Simulation and experimental results show the effectiveness of our method. Supplementary material for this article is available online.     

Micro-prism type single-lens 3D aircraft telescope system

Based on the image payload on an Unmanned Aircraft System, this study utilizes a micro-prism array and single-lens remote camera to assess the feasibility of having two virtual cameras shoot terrain image pairs with inclined ±10°. The software, LightTools, is applied for simulating and verifying the feasibility of the optical system. In comparison with traditional frame-type remote cameras, this study not only could acquire highly overlapped stereoscopic image pairs from different viewing angles, but could also increase the stereoscopic image pairs by two times. The system we propose obtains more stereoscopic digital terrain information than do traditional systems.     

Generalized ICM for image segmentation based on Tsallis statistics

In this paper, the iterated conditional modes optimization method of a Markov random field technique for image segmentation is generalized based on Tsallis statistics. It is observed that, for some q$q$ entropic index values the new algorithm performs better segmentation than the classical one. The proposed algorithm also does not have a local minimum problem and reaches a global minimum energy point although the number of iterations remains the same as ICM. Based on the findings of the new algorithm, it can be expressed that the new technique can be used for the image segmentation processes in which the objects are Gaussian or nearly Gaussian distributed.     

Asymmetric synthesis of a P-chiral heteroditopic ligand via chiral metal template promoted cycloaddition between 3,4-dimethyl-1-phenylphosphole and its sulfonated analog

The asymmetric [4+2] Diels-Alder reaction involving 3,4-dimethyl-1-phenylphosphole, DMPP, as the cyclic diene and its P-sulfonated analogue DMPPS as the dienophile was carried out by utilizing the palladium(II) template complex containing ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary. The reaction proceeded regiospecifically and stereoselectively to give corresponding phosphanorbornene ligand as the major product. Throughout the cycloaddition reaction, DMPP functions chemoselectively as the cyclic diene whilst DMPPS assumes the role of dienophile. The absolute stereochemistry of the novel chiral heteroditopic ligand was established by means of single crystal X-ray diffraction analysis.     

Statistical approach to the code acquisition problem in direct-sequence spread-spectrum communication systems

^** Email: eshima{at}med.oita-u.ac.jp In direct-sequence spread-spectrum (DS/SS) communication, users'original signals are modulated into higher frequencies withthe users' codes. DS/SS communication has the attractive propertythat multiple users' signals can be simultaneously transmitted;however, communication cannot be performed without synchronizationof users' spread-spectrum (SS) signal. Synchronization is typicallyperformed in two steps, i.e. code acquisition and tracking.This paper gives a statistical solution to the question as tohow code acquisition can be performed effectively and precisely.First, properties of matched-filter outputs of SS signal arediscussed. Second, a theoretical method of code acquisitionis proposed according to statistical decision theory. The methoduses all matched-filter outputs for code acquisition. Third,matched-filter outputs are dichotomized with a threshold valueand the dichotomous outputs are used for code acquisition. Asimple and effective method for code acquisition is proposed.Numerical simulations are also given to illustrate the effectivenessof the proposed method. Finally, a further discussion and conclusionto this study are provided.     

Bio-assay based on single molecule fluorescence detection in microfluidic channels

A rapid bioassay is described based on the detection of colocalized fluorescent DNA probes bound to DNA targets in a pressure-driven solution flowing through a planar microfluidic channel. By employing total internal reflection excitation of the fluorescent probes and illumination of almost the entire flow channel, single fluorescent molecules can be efficiently detected leading to the rapid analysis of nearly the entire solution flowed through the device. Cross-correlation between images obtained from two spectrally distinct probes is used to determine the target concentration and efficiently reduces the number of false positives. The rapid analysis of DNA targets in the low pM range in less than a minute is demonstrated.     

An approximation of the Mumford–Shah energy by a family of discrete edge-preserving functionals

We show the Γ$\Gamma$-convergence of a family of discrete functionals to the Mumford and Shah image segmentation functional. The functionals of the family are constructed by modifying the elliptic approximating functionals proposed by Ambrosio and Tortorelli. The quadratic term of the energy related to the edges of the segmentation is replaced by a nonconvex functional.     

Data consistency criterion for selecting parameters for k-space-based reconstruction in parallel imaging

k-space-based reconstruction in parallel imaging depends on the reconstruction kernel setting, including its support. An optimal choice of the kernel depends on the calibration data, coil geometry and signal-to-noise ratio, as well as the criterion used. In this work, data consistency, imposed by the shift invariance requirement of the kernel, is introduced as a goodness measure of k-space-based reconstruction in parallel imaging and demonstrated. Data consistency error (DCE) is calculated as the sum of squared difference between the acquired signals and their estimates obtained based on the interpolation of the estimated missing data. A resemblance between DCE and the mean square error in the reconstructed image was found, demonstrating DCE's potential as a metric for comparing or choosing reconstructions. When used for selecting the kernel support for generalized autocalibrating partially parallel acquisition (GRAPPA) reconstruction and the set of frames for calibration as well as the kernel support in temporal GRAPPA reconstruction, DCE led to improved images over existing methods. Data consistency error is efficient to evaluate, robust for selecting reconstruction parameters and suitable for characterizing and optimizing k-space-based reconstruction in parallel imaging.