HP样品制备站/气相色谱联机系统在苯系物和氯苯类化合物分析中的应用

在定量分析实验中,制备系列标准溶液及校准曲线的制作,可以通过一个HP7686样品制备站/HP6890气相色谱联机系统自动完成。该文应用上述联机系统(?)苯系物和氯苯类化合物的毛细管气相色谱分析中,在低溶度范围获得线性响应良好的校准曲线。

Solvent Extraction of Yttrium by Task-specific Ionic Liquids Bearing Carboxylic Group

A new kind of hydrophobic ionic liquids [1-alkyl-3-（1-carboxylpropyl）im][PF6] has been synthesized, and their extraction.properties for Y（III） in the nitric acid medium was also investigated. The effects of extractant concentration, equilibrium pH of aqueous phase, salt concentration, temperature etc. were discussed. The results show that this kind of Task-Specific Ionic Liquid （TSIL） needs to be saponified before being used for the Y（III） extraction, and the extraction is-acid dependent,-and the extraction efficiency increases with the aqueous phase acldity decreasing. Furthermore, the loaded organic phase is easy to be stripped; more than 95% Y（III） could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol-L-1. The slope analysis technique is used to investigate the extraction mechanism, and a possible cation-exchange extraction mechanism is proposed in the oresent extraction system.

Discriminative Latent Model Based Chinese Multiword Expression Extraction

Discriminative Latent Model(DLM) is proposed for Multiword Expressions(MWEs) extraction in Chinese text to improve the performance of Machine Translation(MT) system such as Template Based MT(TBMT).For MT systems to become of further practical use,they need to be enhanced with MWEs processing capability.As our study towards this goal,we propose DLM,which is developed for sequence labeling task including hidden structures,to extract MWEs for MT systems.DLM combines the advantages of existing discriminative models,which can learn hidden structures in sequence labeling task.In our evaluations,DLM achieves precisions ranging up to 90.73% for some type of MWEs,which is higher than state-of-the-art discriminative models.Such results demonstrate that it is feasible to automatically identify many Chinese MWEs using our DLM tool.With MWEs processing model,BLEU score of MT system has also been increased by up to 0.3 in close test.

Digital Forensic Analysis on Runtime Instruction Flow

Computer system＇s runtime information is an essential part of the digital evidence. Current digital forensic approaches mainly focus on memory and I/O data, while the runtime instructions from processes are often ignored. We present a novel approach on runtime instruction forensic analysis and have developed a forensic system which collects instruction flow and extracts digital evidence. The system is based on whole-system emulation technique and analysts are allowed to define analysis strategy to improve analysis efficiency and reduce overhead. This forensic approach and system are applicable to binary code analysis, information retrieval and matware forensics.

The Impact of Information Technology on Admission Decisions

Information systems have been adopted in many fields including the health industry. Indeed, keeping abreast of the advances of the technological age, many medical organizations have invested heavily in information technologies （IT）, aiming at improving medical decision-making and increasing its efficiency. Despite their obvious advantages, the systems do not always immediately provide the vital medical information required for critical decision-making, and the decisions that are based on this partial information may result in a decreased level of quality of care and unnecessary costs. The objective of this research is to evaluate the contribution of IT to decision-makers （physicians） at the point of care of emergency departments （EDs） by investigating whether the information systems （IS） have improved the medical outcomes, in the complex and highly stressful environment of the ED, with time constraints and overcrowding. The authors evaluated the contribution of the medical information to admission decisions by using the track log-file analysis method. The results were obtained using a unique database containing referrals to the ED from seven main hospitals in Israel. The authors＇ results lead to the major conclusion that viewing medical history contributes to admission decisions and clearly reduces the number of avoidable admissions.

Dynamic Random Access Channel Allocation Scheme Based on the Pseudo-Bayesian Algorithm in OFDMA System

Random Access Channel （RACH） is an uplink contention-based transport channel usually used for initial channel access, bandwidth request, etc. How to use RACH resources effectively is very important in wireless corrnunication systel In this paper, a dynamical RACH allocation scheme is proposed for Orthogonal Frequency-Division Multiple Access （OFDMA） systen. Based on the PseudoBayesian algorithm, this mechanism predicts the number of RACHs for the next frame according to the current load. A new dynamic RACH assignment algorithm and an adaptive access probability method are adopted by the proposed scheme to irrprove the utilization ratio of RACH resources and increase the successful access rate. Numerical simulation shows that the proposed strategy achieves both improvement in the utilization ratio of RACHs and reduction in the access delay compared with other RACH allocation schemes.

Automatic Camera Viewfinder Based on TI DaVinci

Presented is an automatic camera viewfinder based on T1 DaVinci digital platform and discussed mainly is the scheme of software system based on linux. This system can give an alarm and save the picture when the set features appear in the view, and the saved pictures can be downloaded and zoomed out. All functions are operated in OSD menu. It is.well established for its flexible operations, powerful functions, multitasking and stable performance.

Real-time traffic information extraction based on compressed video with interframe motion vector

Extraction of traffic information from image or video sequence is a hot research topic in intelligenttransportation system and computer vision. A real-time traffic information extraction method based on com-pressed video with interframe motion vectors for speed, density and flow detection, has been proposed for ex-traction of traffic information under fixed camera setting and well-defined environment. The motion vectors arefirst separated from the compressed video streams, and then filtered to eliminate incorrect and noisy vectors u-sing the well-defined environmental knowledge. By applying the projective transform and using the filtered mo-tion vectors, speed can be calculated from motion vector statistics, density can be estimated using the motionvector occupancy, and flow can be detected using the combination of speed and density. The embodiment of aprototype system for sky camera traffic monitoring using the MPEG video has been implemented, and experi-mental results proved the effectiveness of the method proposed.

A pseudo wavelet system-based vibration signature extracting method for rotating machinery fault detection

The rotating machinery,as a typical example of large and complex mechanical systems,is prone to diversified sorts of mechanical faults,especially on their rotating components.Although they can be collected via vibration measurements,the critical fault signatures are always masked by overwhelming interfering contents,therefore difficult to be identified.Moreover,owing to the distinguished time-frequency characteristics of the machinery fault signatures,classical dyadic wavelet transforms(DWTs) are not perfect for detecting them in noisy environments.In order to address the deficiencies of DWTs,a pseudo wavelet system(PWS) is proposed based on the filter constructing strategies of wavelet tight frames.The presented PWS is implemented via a specially devised shift-invariant filterbank structure,which generates non-dyadic wavelet subbands as well as dyadic ones.The PWS offers a finer partition of the vibration signal into the frequency-scale plane.In addition,in order to correctly identify the essential transient signatures produced by the faulty mechanical components,a new signal impulsiveness measure,named spatial spectral ensemble kurtosis(SSEK),is put forward.SSEK is used for selecting the optimal analyzing parameters among the decomposed wavelet subbands so that the masked critical fault signatures can be explicitly recognized.The proposed method has been applied to engineering fault diagnosis cases,in which the processing results showed its effectiveness and superiority to some existing methods.

Architecture design for reliable and reconfigurable FPGA-based GNC computer for deep space exploration

SRAM(static random access memory)-based FPGA(field programmable gate array), owing to its large capacity, high performance, and dynamical reconfiguration, has become an attractive platform for So PC(system on programmable chip) development. However, as the configuration memory and logic memory of the SRAM-based FPGA are highly susceptible to SEUs(single-event upsets) in deep space, it is a challenge to design and implement a highly reliable FPGA-based system for spacecraft, and no practical architecture has been proposed. In this paper, a new architecture for a reliable and reconfigurable FPGAbased computer in a highly critical GNC(guidance navigation and control) system is proposed. To mitigate the effect of an SEU on the system, multi-layer reconfiguration and multi-layer TMR(triple module redundancy) techniques are proposed, with a reliable reconfigurable real-time operating system(Space OS) managing the system level fault tolerance of the computer in the architecture. The proposed architecture for the reconfigurable FPGA-based computer has been implemented with COTS(commercial off the shelf) FPGA and has firstly been applied to the GNC system of a circumlunar return and reentry flight vehicle. The in-orbit results show that the proposed architecture is capable of meeting the requirements of high reliability and high availability, and can provide the expressive varying functionality and runtime flexibility for an FPGA-based GNC computer in deep space.