Abnormality detection via SVDD technique of motor-generator system in HEV

This paper introduces a method to detect abnormality of MGS (Motor-Generator System) in HEV (Hybrid Electric Vehicle) using its temperature. The MGS in HEV consists of two Motor-Generators (MG1, MG2), Compound Gear Unit, and etc. The MG1 is to act as a generator in conventional internal combustion engine. And the MG2 is an electric motor to rotate wheel of vehicle using saved electricity in battery or using produced electricity via the MG1. In case of overheating, the electric motors are easily damaged because resistance of wires in motor is abnormally changed. Therefore, detection of abnormally changed temperature in motors (MG1 and MG2) is essential. In this study, the temperature distribution of two Motor-Generators is observed simultaneously in 2-dimensional space. A boundary region of normal operation temperature of two motors is obtained via SVDD technique utilizing Gaussian kernel, one of the most widely being used Mercer kernels. Linear SVDD technique generates boundary of exact ball shape, however SVDD technique using Gaussian kernel can generate nonlinear boundary of distorted ball shape. Abnormality boundary comparison is made between the obtained boundary via SVDD technique and those obtained from conventional temperature range checking method. In order to compare the performance of proposed method, the actual vehicle operation data in excessive driving condition on mountain road is adopted. In verification, simulation shows that warning time due to proposed method is faster and more efficient than those due to conventional method. It is also shown that the reliability of the Motor-Generator System can be improved by using the proposed abnormality detection method.     

Analysis of the effect of cold start on fuel economy of gasoline automatic transmission vehicle

FTP75 driving cycle is used in many countries for evaluation of vehicle fuel economy. FTP75 has 3 phases, where the Phase 1 and the Phase 3 have a same velocity profile, but the Phase1, which is known as cold start phase, shows lower fuel efficiency than the Phase 3. In order to analyze the difference of fuel economy between Phase 1 and Phase 3, vehicle tests are performed. The test results show that the differences of fuel economy is ranging from 3.9% to 18.5%. The factors of the difference of fuel economy for gasoline automatic transmission vehicles are analyzed in this research. The key factors affecting the difference of fuel economy are engine friction loss, torque converter loss and accessory loss. The quantitative analysis of these factors is performed.     

基于 GMap ．N ET 的无人机航迹再现设计与应用磁

三维的飞行仿真技术,数据庞大,建立模型复杂,对计算机要求高,建立针对无人机飞参数据分析的简易航迹再现系统,将有很大的实用价值。为此论文研究了基于GMap ．NET 框架的离线地图嵌入技术,探讨了离线地图数据库的建立原理以及GM apProvider接口原理,并成功应用到无人机航迹再现系统中,实现了多种离线地图的浏览与转换,拓展实现了无人机的航线预置与二维动态演示功能,达到了飞参数据分析的目的。使用结果表明,该系统对资源需求低,可靠性高,操作简洁,易于部署,能够满足对无人机飞参数据分析的需要。     

Scheduling highway work zones with genetic algorithm considering the impact of traffic diversion

Highway work zones caused excessive delay to road users. To reduce user and maintenance costs, work zones shall be designed and scheduled accordingly. An analytical model is developed to jointly optimize work zone lengths and schedule as well as diverted traffic volume for highway maintenance projects, considering time‐varying demand, variable maintenance cost, and various production rates of maintenance crew. With a genetic algorithm, an iterative procedure is developed to search for the optimal solution. A numerical example is illustrated, in which various traffic mitigation plans for a highway maintenance project are evaluated. A sensitivity analysis is conducted, and results indicate the threshold volumes for various conditions (e.g., maintenance crews and capacity of the work zone) at which diverting traffic is desirable. This study demonstrates an effective approach to search for the optimal work zone schedule, which is also applicable to evaluate the effectiveness of traffic diversion plans for a pre‐planned work zone schedule. Copyright © 2012 John Wiley & Sons, Ltd.     

Development of estimation algorithms for vehicle’s mass and road grade

In controlling the longitudinal motion of electrified vehicles such as hybrid vehicles and PHEV (Plug-in Hybrid Electric Vehicles), the variation of the driving resistance loads (or driving loads) such as road grade and actual vehicle mass, is the most influential factor which limits the control performance. Measuring the driving load is not impossible, but it is costly since additional sensors have to be mounted on the vehicle. In this study, methods for estimating vehicle mass and road grade are designed to compensate for the driving loads. The proposed methods are verified using simulation tools and then evaluated experimentally.     

基于Biba模型的三权分立分析

强制访问控制是建设高级别安全信息系统的必要条件.本文基于Biba模型,重点给出了信息系统中系统管理员、安全管理员和安全审计员三权分立的形式化分析.通过分析,给出三权分立管理机制下,保障信息系统安全管理的条件.本文的结果在某国家级信息系统的具体建设中得到了应用.     

Spatial and Temporal Modeling of Beach Use: A Case Study of East Anglia,UK

As tourists are sensitive to weather conditions and changes to the environments they visit, it is likely that climate change will affect coastal recreation in the future. To understand these impacts, it is first important to quantify how visitor numbers are associated with beach characteristics and weather patterns. Using the East Anglian coastline, UK, as a case study, information on the spatial distribution of visitors recorded from aircraft flights is combined with beach characteristic data in a Geographical Information System. In addition, surveys are undertaken at two beaches to assess temporal variations in visitation. The study finds a diverse range of characteristics are associated with visitor numbers. These findings are evaluated alongside the anticipated effects of climate change and management policies. Although it is predicted that warmer weather will increase visitor numbers overall, sea-level rise may reduce numbers at wide sandy beaches, which are currently most preferred by tourists.     

Characterization of Ship Traffic in Right Whale Critical Habitat

Collisions with ships are a significant threat to the endangered North Atlantic right whale. To reduce this threat, The National Oceanic and Atmospheric Administration's (NOAA) National Marine Fisheries Service (NMFS) and the U.S. Coast Guard (USCG) established the Mandatory Ship Reporting System (MSRS) in July 1999. Under this system, all commercial ships, 300 gross tons or greater, are required to report to a shore-based station when entering either of two areas surrounding designated critical habitat: one in waters off the northeastern United States and the other off the southeastern United States. Information reported to the system includes entry location, destination, intended route, and speed. Reporting ships receive an automated message indicating precautionary steps to be taken to avoid hitting whales. Ship tracks between sequential ship locations were estimated by using a geographic information system (GIS) and mapped to illustrate traffic patterns within the MSRS. In the northeast, 69% of all valid tracks transited right whale critical habitat areas. All but two southeastern tracks intersected critical habitat. “High-use” traffic corridors were identified within the system. The majority of ships (59%) traveled at speeds greater or equal to 14 kn, a reported speed at which large whales may be critically injured. This characterization provides a portrait of ship traffic in right whale aggregation areas that can be used to develop measures to reduce the threat of ship strikes to right whales.     

Valuing casualty risk reductions from estimated baseline risk

Stated choice studies have been applied regularly to the valuation of time savings and other attributes of travelling as perceived by individuals. In such experiments, respondents often provide reference levels for the attributes and the hypothetical choices presented to them are pivoted around actual behaviour. However, most individuals are not able to provide reference levels for the number of casualties on the road they travel. Thus, if valuation of this important element is attempted, it is the researcher who must provide casualty risk reference levels to the respondents. Some studies have applied route choice experiments including a safety attribute but the majority has been limited to only one particular road section with a common baseline risk for all respondents.