The control of systems used in pulsed power applications, such as electromagnetic launchers, is difficult due to factors such as short timescales and complex system dynamics. Open loop controllers are often used in su...
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With the development of distributed computing technology and cloud computing technology, the amount of data is rising dramatically, as well as the number of datacenters, where we keep these data for long periods. In t...
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ISBN:
(纸本)9780769549873
With the development of distributed computing technology and cloud computing technology, the amount of data is rising dramatically, as well as the number of datacenters, where we keep these data for long periods. In these datacenters, TCP protocol is still widely used in most of the network traffic. On the other hand, TCP protocol can also result in severe goodput collapse in a high bandwidth and low latency datacenter environment. One of the problems is called incast problem. In order to efficiently utilize the bandwidth of distributed systems such as datacenter environments, some traffic control mechanisms should be very necessary. In this paper, we discussed about an application layer control mechanism to improve the performance of certain traffic pattern which may cause incast problem. The main idea is to make the data flows be staggered and transferred in serialized manner. We conducted both simulation-based and real-machine-based experiments. In the real-machine-based experiments, we conducted both small scale test and large scale test. We find out that the proposed approach, staggered flows, is able to avoid incast problem and to make the performance better in most cases. Also, this paper shows the potential of scalability that this approach can keep the performance well with the increment of node quantity.
Pairing is the first step of decentralized controller design procedure in multi-input multi-output (MIMO) processes. In spite of considerable efforts dedicated to this problem, most of the known pairing techniques are...
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Fixed Pulse Width Modulation (P.W.M.) pattern and P.W.M. wave analyzed by computer is discussed in this paper. To produce this kind of controller, basis of control system is approximated and heuristic control. Paralle...
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ISBN:
(纸本)078031462X
Fixed Pulse Width Modulation (P.W.M.) pattern and P.W.M. wave analyzed by computer is discussed in this paper. To produce this kind of controller, basis of control system is approximated and heuristic control. Parallel Proportional, Integral, Differential (PID) error amplifier is used in this system to optimize and minimize the response time. In designing of this system, availability and cost of technology in developing countries are considered.
In this paper, we present a measurement study of application layer performance in ieee 802.11p vehicular networks. More specifically, our focus is on active safety applications, which are based on the exchange of beac...
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This paper presents the design and implementation of a remote monitoring and control system based on the CDMA2000 1X technology. Nowadays CDMA2000 1X system has added a series of packet equipment to construct the pack...
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ISBN:
(纸本)9784907764289
This paper presents the design and implementation of a remote monitoring and control system based on the CDMA2000 1X technology. Nowadays CDMA2000 1X system has added a series of packet equipment to construct the packet network and provide high speed packet data services. The packet network can provide two kinds of Internet accesses: simple IP and mobile IP. The paper adopts the mobile IP technology to carry out Internet access. The wireless monitoring system is a data collecting system using wireless communication technologies. The sensor node acquires data from various types of sensors. Then the central server is equipped with network devices to access Internet and collects the sensor data transmitted through a wireless channel from hundreds of sensor nodes scattered in the service area. The proposed system can be adapted to many types of applications such as industrial and medical remote monitoring systems, security systems, factory automation systems, and remote metering systems. Moreover, it has been put into practice in the oil field on the sea. In practical applications of the monitoring system, the information transferred via the wireless network include such parameters as oil pressure, battery cell voltage, memory capacity, clock and other working conditions. The paper presents the hardware architecture and software structure of the system and analyzes the bit error rate. The results show that the proposed system can meet the locale requirement.
A novel capturing method of tumbling objects in non-gravitational field is proposed, aiming for the future on-orbit service missions such as capturing failed satellites or manned vehicle which loses control, or removi...
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A novel capturing method of tumbling objects in non-gravitational field is proposed, aiming for the future on-orbit service missions such as capturing failed satellites or manned vehicle which loses control, or removing debris. The key technology for this capture is how to compensate for the difference of rotational motions between the chaser and the target at the moment of capture. Most conventional methods use manipulator movement for this objective while keeping the position and attitude of the chaser body constant, which limits the allowable rotational velocity and patterns of the tumbling motion of the target. In the proposed method, the chaser aligns its rotational motion with the target's one by appropriate control before capturing the target, which is expected to enlarge the allowable target rotational motion range. Technical issues to realize it are discussed and our approach to them are proposed, which is verified with some computer simulations and hardware experiments.
This work proposes a singularity free stabilizing controller for a non-holonomic mobile robot. The control objective is to force the system states from any initial position to the origin in finite time. In the first s...
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ISBN:
(纸本)9781665441186
This work proposes a singularity free stabilizing controller for a non-holonomic mobile robot. The control objective is to force the system states from any initial position to the origin in finite time. In the first step the state transformation has been done on the kinematic and dynamic model of the mobile robot. After transformation the kinematic and dynamic model has been converted to non-holonomic integrator and non-holonomic double integrator respectively. Further a novel sliding surface has been proposed in the paper which stabilizes both non-holonomic integrators in finite time. Kinematic stabilization has been done using power rate reaching law of sliding mode controller (SMC) and dynamic stabilization of mobile robot has been done using relay free SMC technique. Stability analysis of the proposed kinematic and dynamic controller has been given using Lyapunov stability theory. Simulations studies are performed, and it is shown that the proposed controller is better than the existing state of the art.
The application of model predictive algorithms for three-phase electric drives has gained an impressive attention in the last decade. Nowadays, the model predictive controls (MPC) represent one of the most competitive...
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ISBN:
(纸本)9784886864055
The application of model predictive algorithms for three-phase electric drives has gained an impressive attention in the last decade. Nowadays, the model predictive controls (MPC) represent one of the most competitive solutions in alternative to the conventional feedback control schemes. At the same time, multiphase motor drives have become a feasible solution for high power/high current applications and most likely they will be employed in the applications like transportation electrification and energy production. Although the technical literature contains many references regarding the application of MPC for three-phase drives, there are only few attempts about the application of predictive algorithms for multiphase machines. The paper provides a comprehensive analysis and survey on the main MPC schemes applied to multiphase drives. In addition, experimental results on the application of a MPC scheme for a six-phase asymmetrical induction machine are provided.
Electric phenomena play an important role in biophysics. Bioelectric processes control the ion transport processes across membranes, and are the basis for information transfer along neurons. These electrical effects a...
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ISBN:
(纸本)0780371208
Electric phenomena play an important role in biophysics. Bioelectric processes control the ion transport processes across membranes, and are the basis for information transfer along neurons. These electrical effects are generally triggered by chemical processes. However, it is also possible to control such cell functions and transport processes by applying pulsed electric fields. This area of bioengineering, bioelectrics, offers new applications for pulsed power technology. One such application is prevention of biofouling, an effect that is based on reversible electroporation of cell membranes. Pulsed electric fields of several kV/cm amplitude and submicrosecond duration have been found effective in preventing the growth of aquatic nuisance species on surfaces. Reversible electroporation is. also used for medical applications, e.g. for delivery of chemotherapeutic drugs into tumor cells, for gene therapy, and for transdermal drug delivery. Higher electric fields cause irreversible membrane damage. Pulses in the microsecond range with electric field intensities in the tens of kV/cm are being used for bacterial decontamination of water and liquid food. A new type of field-cell interaction, "Intracellular Electromanipulation", by means of nanosecond pulses at electric fields exceeding 50 kV/cm has been recently added to known bioelectric effects. It is based on capacitive coupling to cell substructures, has therefore the potential to affect transport processes across subcellular membranes, and may be used for gene transfer into cell nuclei. There are also indications that it triggers intracellular processes, such as programmed cell death, an effect, which can be used for cancer treatment. In order to generate the required electric fields for these processes, high voltage, high current sources are required. The pulse duration needs to be short to prevent thermal effects. Pulse power technology is the enabling technology for bioelectrics. The field of bioelectrics, there
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