The Influence of Blocking Mass Parameters on the Vibration Isolation Performance of a Power Cabin

Rigid blocking masses are located in the typical base structure of a power cabin based on the impedance mismatch principle.By combining the acoustic-structural coupling method and statistical energy analysis,the full-band vibration and sound radiation reduction effect of vibration isolation masses located in a base structure was researched.The influence of the blocking mass’ cross-section size and shape parameters and the layout location of the base isolation performance was discussed.Furthermore,the effectiveness of rigid vibration isolation design of the base structure was validated.The results show that the medium and high frequency vibration and sound radiation of a power cabin are effectively reduced by a blocking mass.Concerning weight increment and section requirement,suitably increasing the blocking mass size and section height and reducing section width can result in an efficiency-cost ratio.

Times Series Prediction to Basis of a Neural Network Conceived by a Real Genetic Algorithm

Neural network and genetic algorithms are complementary technologies in the design of adaptive intelligent system. Neural network learns from scratch by adjusting the interconnections betweens layers. Genetic algorithms are a popular computing framework that uses principals from natural population genetics to evolve solutions to problems. Various forecasting methods have been developed on the basis of neural network, but accuracy has been matter of concern in these forecasts. In neural network methods forecasted values depend to the choose of neural predictor structure, the number of the input, the lag. To remedy to these problem, in this paper, the authors are investing the applicability of an automatic design of a neural predictor realized by real Genetic Algorithms to predict the future value of a time series. The prediction method is tested by using meteorology time series that are daily and weekly mean temperatures in Melbourne, Australia, 1980-1990.

Evaluation of Station Keeping Systems for Deepwater Drilling Semi-submersibles

This paper addresses the need for systematic evaluation of the station keeping systems of deepwater drilling semi-submersibles.Based on the selected drilling semi-submersible configuration, the mooring systems were analyzed and designed for a range of water depths using different mooring line materials.These were steel wire rope, polyester rope and HMPE (high modulus poly ethylene).The mooring analysis was carried out using the advanced fully coupled time domain analysis method in the computer software package HARP.Diffraction analysis was first applied to solve the hydrodynamic properties of the vessel and then the motion equations of the complete dynamic system including the drilling rig, the mooring lines and risers were developed and solved in the time domain.Applying the advanced analysis method, a matrix of mooring systems was developed for operating in water depths of 1000 m, 1500 m, and 2 000 m using various mooring materials.The development of mooring systems was conducted in accordance with the commonly adopted mooring design code, API RP 2SK and API RP 2SM.Fresh attempts were then made to comparatively evaluate the mooring system's characteristics and global performance.Useful results have been obtained in terms of mooring materials, water depths, and key parameters of mooring configurations.The results provide in-depth insight for the design and operation of deepwater mooring systems in the South China Sea environment.

Intelligent Tracking Telescope Using Embedded Microcontrollers

This paper presents the design and implementation of the embedded microcontrollers within a telescope control system. The design objectives of the overall system are to automatically find light emitting objects at night within a user specified area, to track a light emitting object for a user specified time given the initial position of the object, and to allow the user access to these functions through a graphical user interface. The embedded system is used to provide a communication link between the graphical user interface and system hardware, to provide angle data processing for a dual axis accelerometer, to provide data processing for an electronic compass, and to provide pulse outputs for the step and direction inputs of three stepper motor drives. This paper will describe the design, implementation, and results of each of these objectives.

Design and Implementation of a Single-Phase Energy Meter with SMS Controlled and Monitored Recharge Capability

The Nigerian power sector is faced with poorly organized billing and consumer relations management. Tariff billing and collection has been a big problem in some community in Nigeria even with the introduction of prepaid meters. The process of payment is cumbersome and stressful as consumers have to go and pay in banks and then take tellers to power utility office to confirm their power bills payment before they can recharge their cards. The major purpose of this work is to design and implement a convenient, cashless, automated and transparent electricity metering, billing and payment system. This project combines the power electronic meter with a communications network which in this case is a GSM （global system for mobile） network. Remote electricity billing is a unique concept, in which the electricity board can collect the consumed units＇ data from consumer on mobile phone using GSM network. A unique property of this system is that, the electricity board can disconnect or reconnect consumers from remote location through the mobile phone. As this project works on GSM network, the system can be controlled from any part of the country.

Field Test of Energy Storage System on Urban Transit System

The energy storage system charges the energy generated during braking and discharges it again when a vehicle accelerates on urban transit system. The energy storage system is considered to be one of the useful devices for energy storing and recycling. The energy storage system was developed and installed on the test track of Gyeongsan LRT in Korea. This paper presents the test plan and how much energy is saved by the energy storage system through the field test. When the energy storage system is on/off, the energy saving rate is obtained.

动能经济管理方法

本文就动能经济的管理方法进行了剖析。

Customized Optimization for Vehicle Acoustic Statistical Energy Analysis

Statistical Energy Analysis(SEA) is one of the conventional tools for predicting vehicle high-frequency acoustic responses.This study proposes a new method that can provide customized optimization solutions to meet NVH targets based on the specific needs of different project teams during the initial project stages.This approach innovatively integrates dynamic optimization,Radial Basis Function(RBF),and Fuzzy Design Variables Genetic Algorithm(FDVGA) into the optimization process of Statistical Energy Analysis(SEA),and also takes vehicle sheet metal into account in the optimization of sound packages.In the implementation process,a correlation model is established through Python scripts to link material density with acoustic parameters,weight,and cost.By combining Optimus and VaOne software,an optimization design workflow is constructed and the optimization design process is successfully executed.Under various constraints related to acoustic performance,weight and cost,a globally optimal design is achieved.This technology has been effectively applied in the field of Battery Electric Vehicle(BEV).

Analysis on the risk factors of second fracture in osteoporosis-related fractures

Objective： To explore the clinical characteristics and risk factors of refracture in patients suffering from osteoporosis-related fractures as well as effective interventions. Methods： From January 2006 to January 2008, both out-patients and in-patients in our hospital who were over 50 years old and suffered from osteoporosis-related fractures were selected for this research. They were divided into fracture group and refracture group. The refracture rate was followed up for 2 years, during which 11 patients developed refracture, thus were included in the refracture group. Therefore, 273 patients, 225 first-fracture cases, aged （67.7± 8.5） years, and 48 refracture cases, aged （72.7±9.5） years, were included in this study. General data including age and sex, fracture types, femoral neck bone mineral density （BMD） T-scores tested by dual-energy X-rays absorptiometry （DEXA）, Charlson index, time-frame between two fractures as well as mobility skill assessment were collected and analyzed by single-factor and multivariate statistical methods. Results： Females accounted for 70.2% of the fracture group and 77.1% of the refracture group. The most common refracture type was vertebral fracture for the first time and femoral neck fracture for the second time during the followup. The second fracture happened 3.7 years after the first one on average. The refracture rate was 2.12% within one year, and 4.66% within two years. Risk factors for a second fracture in osteoporotic fracture patients included age （〉75 years, HR=1.23, 95%CI 1.18-1.29; 〉85 years, HR=1.68, 95% CI 1.60-1.76）, female sex （HR=1.36, 95%CI 1.32-1.40）, prior vertebral fractures （HR= 1.62, 95%CI 1.01-2.07）, prior hip fractures （HR=1.27, 95%CI 0.89-2.42）, BMD T-score〈-3.5 （HR-1.38, 95%CI 1.17-1.72） and weakened motor skills （HR=1.27, 95%CI 1.09-1.40）. Conclusions： The risks of second fracture among patients with initial brittle fracture are substantial. There is adequate time between the first and second fractures for interventions to reduce the risks of refracture, especially for the old women with a vertebral or hip fracture. Medication, motor functional rehabilitation and fall-down prevention training are helpful.

CONSENSUS DESIGN FOR CONTINUOUS-TIME MULTI-AGENT SYSTEMS WITH COMMUNICATION DELAY

This paper investigates a consensus design problem for continuous-time first-order multiagent systems with uniform constant communication delay.Provided that the agent dynamic is unstable and the diagraph is undirected,sufficient conditions are derived to guarantee consensus.The key technique is the adoption of historical input information in the protocol.Especially,when agent's own historical input information is used in the protocol design,the consensus condition is constructed in terms of agent dynamic,communication delay,and the eigenratio of the network topology.Simulation result is presented to validate the effectiveness of the theoretical result.