automated test case generation for the stress testing of multimedia systems

With the advancement in network bandwidth and computing power, multimedia systems have become a popular means for information delivery. However, general principles of system testing cannot be directly applied to testing of multimedia systems on account of their stringent temporal and synchronization requirements. In particular, few studies have been made on the stress testing of multimedia systems with respect to their temporal requirements under resource saturation. Stress testing is important because erroneous behavior is most likely to occur under resource saturation. This paper presents an automatable method of test case generation for the stress testing of multimedia systems. It adapts constraint solving techniques to generate test cases that lead to potential resource saturation in a multimedia system. Coverage of the test cases is defined upon the reachability graph of a multimedia system. The proposed stress testing technique is supported by tools and has been successfully applied to a real-life commercial multimedia system. Although our technique focuses on the stress testing of multimedia systems, the underlying issues and concepts are applicable to other types of real-time systems.

Real-time non-destructive testing of dynamic holograms in doubly-doped LiNbO3 crystals using phase-conjugate technique

Nankai University

Aspheric surface testing with a liquid compensatory interferometer

A simple method of testing deep aspheric surfaces is presented. The apparatus consists of a Twyman-Green interferometer and a liquid compensatory container. Two lenses, one with spherical surfaces and the other with a spherical surface and an aspheric surface, were tested by using this method. The device is very simple and easy to assemble. (C) 1998 Society of Photo-Optical Instrumentation Engineers.

Design,Fabrication,and Testing of Single-Side Alignment of 16×0.8nm Arrayed-Waveguide Grating

A novel design of 100GHz-spaced 16channel arrayed-waveguide grating (AWG) based on silica-on-silicon chip is reported.AWG is achieved by adding a Y-branch to the AWG and arranging the input/output channel in a neat row,so the whole configuration can be aligned and packaged using only one fiber-array.This configuration can decrease the device's size,enlarge the minimum radius of curvature,save time on polishing and alignment,and reduce the chip's fabrication cost.

Design, simulation and testing of large area silicon drift detectors and detector array for X-ray spectroscopy

Large area (25 mm(2)) silicon drift detectors and detector arrays (5x5) have been designed, simulated, and fabricated for X-ray spectroscopy. On the anode side, the hexagonal drift detector was designed with self-biasing spiral cathode rings (p(+)) of fixed resistance between rings and with a grounded guard anode to separate surface current from the anode current. Two designs have been used for the P-side: symmetric self-biasing spiral cathode rings (p(+)) and a uniform backside p(+) implant. Only 3 to 5 electrodes are needed to bias the detector plus an anode for signal collection. With graded electrical potential, a sub-nanoamper anode current, and a very small anode capacitance, an initial FWHM of 1.3 keV, without optimization of all parameters, has been obtained for 5.9 keV Fe-55 X-ray at RT using a uniform backside detector.

Testing a single-aliquot protocol for recuperated OSL dating

IEECAS SKLLQG

基于P2P技术的CSRe冷却装置控制系统设计；Design of Control System for CSRe Cooling Equipment Based on P2P Technology

HIRFL-CSR工程对CSRe冷却装置电子冷却部分的控制系统在实时性和可靠性方面提出了非常高的要求。电子冷却工作环境复杂,各种干扰难以预测。从电子冷却的控制系统改进出发,以实现电子冷却的自动调束为目标,以高端FPGA和ARM嵌入式系统为基础,采用P2P通讯技术和神经元网络算法来实现对电子冷却的自动控制。该控制系统对电子冷却控制的完善提供了先进的硬件平台和软件实现方案。

Instrumented impact testing of phenolphthalein polyether ketone

The Charpy impact fracture behaviour of unnotched specimens of phenolphthalein polyether ketone (PEK-C) was studied over a temperature range from room temperature to 220 degrees C by using an instrumented impact tester. The load-time and energy-time curves of PEK-C at different temperatures were recorded. From these curves, some important parameters, such as the maximum impact load, the maximum stress, the total impact energy, the crack initiation energy, the crack propagation energy etc., were obtained and their temperature dependences of PEK-C were investigated. The point of 100 percent maximum load on the load-time trace was shown to be the yield point. Two parameters, the ductile ratio (D.R.) and the ductility index (D.I.) were applied to characterize the ductility of PEK-C and their relationships to the relaxation processes were discussed.

改进型地雷引信压发测试台

针对原地雷引信压发测试台存在的问题,提出改进方法和措施;详细介绍了改进后测试台的系统构成以及工作原理。改进前后的对比结果表明,改进型测试台实现了漏检率为0,无链条卡死现象,能够适用4种引信,且外表美观。

释光测年实验室的建立与沉积物释光测年技术研究

The main research projects reported in this paper are the establishment of a luminescence (OSL/TL) dating laboratory in The Institute of Geology and Geophysics, CAS, and studies on OSL dating technique and protocol of sediments from North China. These projects have been suggested in order to fit in with the needs of research developments in environmental changes, in particular the aridity and desertification in North China. A new luminescence dating laboratory in which there are a Rise TL/OSL-DA-15B/C reader with Sr-90 beta source, a set of Little More Tape 9022 alpha and beta irradiators, three set of Daybreak 583 intelligent alpha counters and sample preparation system has been set up in the Institute in June 2001. The courses of the establishment of a new laboratory involved a series of technical works, besides making a suitable choice of the equipment, as follows: installing and testing TL/OSL reader, calibrating the dose rate of the beta and alpha sources in the irradiators with the standard sources, testing and calibrating the count rates of the thick source alpha counting in the alpha counters with a standard sample, and then dating of the know age samples to check and examine the OSL/TL dating system. All data obtained from above calibrations and tests show that the established OSL/TL system, including the used equipment in it, can be used to determine age of the geological and archaeological samples with an error of equivalent dose (De) of less than 5%. The OSL dates of several sediment samples obtained from the system are good agreement with those from the OSL dating laboratory in Hong Kong University and ~(14)C dates within 1 - 2 standard deviations. The studies on OSL dating technique and protocol of sediment samples being in progress involve the De determinations with single aliquot regeneration (SAR) (Murray and Wintle, 2000) of the coarse grain quartz from sand dune samples and comparison of the De determinations obtained from SAR with those measured by using multiple aliquot regeneration of loess fine grains. The preliminary results from these research works are shown as follows. The very low natural equivalent dose (De) of about 0.012 - 0.03 Gy, corresponding age of less than 10 years, for BLSL (blue light stimulated luminescence) of the coarse grain quartz from modern sand dune samples in Horqin sand fields has been determined with both the SAR and multiple aliquot regeneration (MAR) techniques. This imply that the BLSL signal zeroing of the quartz could be reached before burying of the sand in Horqin sand fields. The De values and ages of the coarse grain quartz measured with SAR protocol are in good agreement with those obtained from multiple aliquot technique for the modern sand dune samples, but the errors of De from the MAR is greater than those from the SAR. This may imply that the higher precision of age determination for younger sand dune samples could be achieved with the SAR of coarse grain quartz. The MAR combining with "Australian Slide method" may be a perfect choice for De measurements of loess fine grain samples on the basis of analysis of De values obtained from the SAR and from the MAR. The former can be employed to obtain a reliable age estimate of loess sample as older as approximately SO ka BR There is a great difference between De determinations from the (post-IR) OSL of the SAR (Roberts and Wintle, 2001) and those from independent or expected estimates for the older samples. However, the age estimates obtained from the (post-IR) OSL of the SAR are mostly closed to the independent age determinations for the younger (age less than 10 ka) fine grain samples. It may be suggested that the (post-IR) OSL of the SAR protocol of the fine grain fraction would be a suitable choice to dating of the younger samples, but may be unsuitable for the older samples.