33 research outputs found
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Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks
无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216
A clustering engine for data rate reduction in the Belle II pixel detector
The DEPFET technology has been chosen as the baseline for the vertex pixel detector of the Belle II experiment at KEK\Japan. This detector consist of 22 modules, each proposed to be equipped with 2 × 250 × 512 pixel. With the proposed average readout frequency of 10kHz and 30kHz peak rate a huge data stream of approx. 100Gbit/s will be generated. To reduce this data stream to a more feasible value, we have to take advantage of the low occupancy of approx. 1−2% and the the hit distribution within the pixel array. For this purpose a pipelined clustering algorithm was developed, which can handle cluster sizes of 3 × 3 or 5 × 5 at full readout speed. These algorithm can handle data from non bricked sensors and also from bricked designs. It is able to reduce the data rate by up to 50%. The collection of the clustered data packages from the row wise parallel pipeline are controlled by a specially developed
output scheduler, which assures together with the corresponding FIFO structures the data-handling capability. In this paper we will present the overall structure of such a DCE (Data Clustering Engine) and also the details of the implemented clustering and output scheduling algorithms. Furthermore the impacts of the constraints on speed, power and area on the developed circuit and the chosen realization given by the experiment environment
will be discussed in detail
Radiation studies of silicon-microstrip detectors for use in ATLAS and SCT
Silicon detectors from both standard-silicon and oxygenated-silicon material, which were radiation hard to the dose level expected after ten years of operation in ATLAS, was developed. After irradiation, the detector current decreases throughout the entire annealing period. Results showed that oxygenated detectors were of higher leakage current than standard silicon detectors after irradiation, while the current annealing was similar for two types. (Edited abstract) 6 Refs
A fast readout using switched current techniques for a DEPFET-pixel vertex detector at TESLA
A fully depleted silicon detector with a first amplifying transistor integrated in every pixel (DEPFET) is a promising
proposal for the pixel-based vertex detector at TESLA. The DEPFET offers good spatial resolution, an excellent signalto-
noise ratio and low power consumption in a row-wise operation mode. A readout concept for a DEPFET pixel array
matching the requirements at TESLA is described. In order to meet the operation specifications at TESLA (50 MHz
row rate), a readout architecture based on current mode techniques (Switched Current) is presented. It contains stand
alone zero suppression offering a triggerless operation. The core of the readout chip, a fast operating current memory
cell, is discussed in detail. The results of a first prototype chip, CURO I (CUrrent ReadOut), show that the
requirements for TESLA are achievable
Effects of gamma irradiation on DEPFET pixel sensors for the Belle II experiment
For the Belle II experiment at KEK (Tsukuba, Japan) the KEKB accelerator was upgraded to deliver a 40 times larger instantaneous luminosity than before, which requires an increased radiation hardness of the detector components. As the innermost part of the Belle II detector, the pixel detector (PXD), based on DEPFET (DEpleted P-channel Field Effect Transistor) technology, is most exposed to radiation from the accelerator. An irradiation campaign was performed to verify that the PXD can cope with the expected amount of radiation. We present the results of this measurement campaign in which an X-ray machine was used to irradiate a single PXD half-ladder to a total dose of 266 kGy. The half-ladder is from the same batch as the half-ladders used for Belle II. According to simulations, the total accumulated dose corresponds to 7–10 years of Belle II operation. While individual components have been irradiated before, this campaign is the first full system irradiation. We discuss the effects on the DEPFET sensors, as well as the performance of the front-end electronics. In addition, we present efficiency studies of the half-ladder from beam tests performed before and after the irradiation