计及螺旋桨负载的船舶电力系统协调控制设计

推进负载对船舶电网的暂态稳定性影响是船电系统的主要特征之一.本文基于非线性鲁棒L2干扰抑制控制方法,研究了具有螺旋桨负荷的船舶电力系统中的励磁与调速的协调控制问题,在充分分析了柴油发电机组的非线性数学模型及其螺旋桨负载的相互耦合的非线性动态结构特性的基础上,提出backstepping控制技术与L2干扰抑制相结合的综合协调控制策略来设计控制器.该控制器在保证系统稳定的条件下,有效地抑制干扰对发电机系统电压和频率的影响.仿真表明,在给系统突加螺旋桨负载的情况下,该控制器能有效地抑制负载对系统性能的影响,验证了控制器的有效性.     

Developing a computer program to facilitate language training

The present research demonstrates how an instructional program developer can be used as a subject in a series of experiments to determine optimum parameters for a computer program. The research included developing and testing a new training procedure for presentation of English to Spanish and Spanish to English word pairs. The experiments demonstrated that number of word pairs used per lesson (5, 10, or 15 pairs) did not influence how much was learned when lessons were repeated on 3 consecutive days. Constant as opposed to varied orders of pair presentation did not affect the rate at which pairs were learned. Tests with feedback on word pairs 5 and 15 days after training prevented an increase in errors 25 days after training. Repeating lessons on 3 consecutive days as opposed to just 1 day led to fewer errors during tests that occurred 5 or 15 days after training. It did not matter if Spanish to English pairs were presented before or after English to Spanish pairs during a daily training session. In addition, intermixing Spanish to English and English to Spanish pairs did not lead to better performance as compared to presenting English to Spanish or Spanish to English pairs first. The present experiments show how a software developer can be used as the subject in a series of experiments to determine parameters for an educational computer program.     

Interactive computer graphics applied to the theoretical aircraft/store separation problem

Recently, a computer program was developed which computes the theoretical trajectory of a store in the complex flow field after release from an aircraft flying at subsonic speeds. However, the engineer still had the exceptionally difficult problem of preparing the source and sink models which are part of the computer program input.Views of the interactive graphics console illustrate how an interactive graphics computer program (SOURCE) is used to prepare source and sink theoretical aerodynamic models for the aircraft fuselage, nacelles, fuel tanks, and store bodies. Use of this interactive graphics computer program reduces the calendar time required to develop a source and sink model from approximately 2 weeks to 1 h. This reduction in required calendar time permits theoretical store separation analyses to be conducted for a store in the early development program when the store shape is frequently being changed.     

计算机视觉中图匹配研究进展: 从二图匹配迈向多图匹配

图匹配试图求解二图或多图之间节点的对应关系.在图像图形领域,图匹配是一个历久弥新的基础性问题.从优化的角度来看,图匹配问题是一个组合优化问题,且在一般情形下具有非确定性多项式复杂程度(non-deter-ministic polynomial, NP)难度的性质.在过去数十年间,出现了大量求解二图匹配的近似算法,并在各个领域得到了较为广泛的应用.然而,受限于优化问题本身的理论困难和实际应用中数据质量的种种限制,各二图匹配算法在匹配精度上的性能日益趋近饱和.相比之下,由于引入了更多信息且往往更符合实际问题的设定,多图的协同匹配则逐渐成为了一个新兴且重要的研究方向.本文首先介绍了经典的二图匹配方法,随后着重介绍近年来多图匹配方法的最新进展和相关工作.最后,本文讨论了图匹配未来的发展.     

Image pre-compensation to facilitate computer access for users with refractive errors

Computer technologies, frequently employed for everyday tasks, often use Graphical User Interfaces (GUIs), presented through monitors or LCD displays. This type of visual interface is not well suited for users with refractive visual limitations, particularly when they are severe and not correctable by common means. In order to facilitate computer access for users with refractive deficiencies, an algorithm has been developed, using a priori knowledge of the visual aberration, to generate on-screen images that counter the effect of the aberration. When the user observes the screen displaying a pre-compensated image, the image perceived in the retina will be similar to the original image. The algorithm was tested by artificially introducing a spherical aberration in the field of view of 14 subjects, totaling 28 individual eyes. This use of pre-compensation improves the visual performance of the subjects with respect to that achieved with no compensation.     

A model to facilitate costing,pricing and budgeting of computer services

This paper addresses the problem of establishing a financial policy for managing computer systems, and proposes a model incorporating the three facets of determining the cost rates of hardware resources, evaluating the impact of pricing policy, and budget planning. This approach is based on statistical analysis of the correlation among the consumption of various hardware resources.     

Computer program to predict the gas exchange process of a diesel engine

Ruston Paxman Diesels Ltd has made much use of computer programs in the development of diesel engines, in particular for the prediction of thermodynamic performance. The original program for this purpose has undergone considerable change, both to improve the accuracy and extend the application. These changes have resulted in the program becoming unnecessarily complicated for the designer to use.By returning to first principles a new program has been written that is considerably more versatile than the old one, and which is far simpler to use because data preparation is now governed solely by the complexity of the problem being tackled. This program is described.     

Fault detection and diagnostic method of diesel engine by combining rule-based algorithm and BNs/BPNNs

The stable operation of diesel engine is critical to the normal production of the industry, and the prevention, monitoring, and identification of faults are of great significance. At present, the fault research on diesel engines still has some defects, such as only few types of faults diagnosis are identified, the accuracy of fault diagnosis is still low, and fault identification is located at a fixed speed. A novel fault detection and diagnostic method of diesel engine by combining rule-based algorithm and Bayesian networks (BNs) or Back Propagation neural networks (BPNNs) is proposed. The signals are processed by wavelet threshold denoising and ensemble empirical mode decomposition. The signal-sensitive feature values are extracted from the decomposed intrinsic mode function. Seven faults are roughly identified using rule-based algorithm and finely identified using BNs or BPNNs. Results show the proposed fault diagnosis method has a good diagnostic performance for a wide range of rotation speeds when the training data for BNs and BPNNs are from fixed speeds. In addition, the influences of the layers of decomposed signals, sensor noise and external excitation interference on the fault diagnostic performance are also researched.     

甲骨文计算机辅助缀合系统设计

计算机辅助甲骨文碎片缀合,是整理甲骨的一种先进技术。研究了甲骨片图像的轮廓信息的提取与轮廓跟踪算法、轮廓片段特征向量提取算法,建立了甲骨文碎片数据库,研制了基于边界匹配的甲骨文缀合辅助系统,选定待缀合的甲骨碎片后,该系统可以自动生成疑是目标甲骨碎片的动态数据库,甲骨文专家只需要基于“备选甲骨碎片数据库”通过人机交互来实现甲骨文缀合。     

Design and implementation of an autonomous EGR cooling system using deep neural network prediction to reduce NOx emission and fuel consumption of diesel engine

Neural Computing and Applications - This study includes the design of an autonomous exhaust gas recirculation (EGR) cooling system and implementation of the system on diesel engine by using deep...     

Correction to: Design and implementation of an autonomous EGR cooling system using deep neural network prediction to reduce NOx emission and fuel consumption of diesel engine

Neural Computing and Applications - article.     

Practical design of a proxy agent to facilitate adaptive video streaming service across wired/wireless networks

Thanks to the growing of the wireless networks, the video streaming application becomes a ubiquitous joyful service. In a wireless communication network environment, the service traffic spans across the wired and wireless domains. In this article, we propose a practical design of a proxy agent - SPONGE (Stream Pooler Over a Network Graded Environment) sitting between the wireless User Equipments (UEs) and the video streaming server to facilitate the adaptive video streaming service across wired/wireless networks. To make the wireless streaming service more efficient, an input video session would be encoded as multiple qualities of video streams so that UEs with a similar receiving condition can share streams with the same service quality via SPONGE. SPONGE can alleviate the direct load on the original stream broadcasting server. Meanwhile, it can make each UE get an adaptive streaming service according to the network conditions of the UE by a reduced network condition feedback latency. Our theoretical analysis and simulation results show that SPONGE can help wireless streaming users get a smooth and better playback quality by a quick and accurate reaction to the network condition.     

A Monte Carlo FORTRAN 200 programme for the determination of static properties of liquids vectorized to run on the CYBER 205 vector processing computer

We present a Monte Carlo programme version written in Vector-FORTRAN 200 which allows a fast computation of thermodynamic properties of dense model fluids on the CYBER 205 vector processing computer.A comparison of the execution speed of this programme, a scalar version and a vectorized molecular dynamics programme showed the following: (i) the vectorized form of the Monte Carlo programme runs about a factor of 8 faster on the CYBER 205 than the scalar version on the conventional computer CYBER 855; (ii) for small ensembles of 32–108 particles, the Monte Carlo programme is of about the velocity as the molecular dynamics one. However, for larger numbers of particles, the molecular dynamics programme is vastly faster executed on the CYBER 205 than the Monte Carlo programme, particularly when neighbour tables are used. We propose a technique to accelerate the Monte Carlo programme for larger ensembles.     

Synoname1: The Getty''s new approach to pattern matching for personal names

Synoname¹: The Getty's new approach to pattern matching for personal names     

基于软件技术的IPv6/IPv4主机隧道构建方法

IETF针对如何顺利完成从IPv4到IPv6的过渡提出了很多方案,其中应用较广的是隧道机制。利用socket、MySQL C、WinExec等技术,提出了一个使用软件技术在Windows2000与RedHatLinux9．0之间建立IPV6/IPv4主机隧道的方法,该方法可方便用户对主机隧道的建立和管理。     

Internet access to real equipment at computer architecture laboratories using the java/CORBA paradigm

Laboratory courses in Engineering and Computer Science are not always easy to implement using Internet-based distance education. Simulation has its limits, when compared to working with the real thing (like a computer board). The system we present in this paper provides remote access to real equipment used in a Computer Architecture laboratory. It uses CORBA technology to manage real equipment as just another set of CORBA objects whose operations can be invoked remotely by students. Apart from accessibility advantages for students, there are important benefits for academic institutions. Our system allows different configurations that provide different levels of equipment availability, using fewer resources than a conventional laboratory, and reducing costs. This paper describes our system and its functional architecture, and analyzes economic savings for academic institutions.     

A framework for extending computer aided process planning to include business activities and computer aided design and manufacturing (CAD/CAM) data retrieval

Computer aided process planning (CAPP) systems have had limited success in integrating business functions and product manufacturing due to the inaccessibility and incompatibility of information residing in proprietary software. While large companies have developed or purchased complex order management and engineering applications, smaller manufacturers continue to use semi-automated and manual methods for managing information throughout the lifecycle of each new product and component. There is a need for reconfigurable and reprogrammable systems that combine advances in computer aided design (CAD/Computer Aided Manufacturing (CAM) technology and intelligent machining with product data management for documentation and cost control. The goal of this research is to demonstrate an architecture in which customer service, CAPP and a costing methodology known as activity based costing (ABC) are incorporated into a single system, thereby allowing companies to monitor and study how expenditures are incurred and which resources are being used by each job. The material presented in this paper is the result of a two year university and industry sponsored research project in which professors and students at the Costa Rica Institute of Technology developed a software application for FEMA Industrial S.A., a local machining and fabrication shop with sixty five employees and both conventional and CNC capabilities. The final results represent not only a significant contribution to local industry and to the students’ education but, also to the continuing growth of CAPP. Implementing better decision making tools and standardizing transactions in digital format would reduce the workload on critical personnel and archive valuable knowledge for analyzing company methods and expertise.     

基于B/S模式高校机房管理支撑平台的设计与实现

由于计算机硬件的不断更新换代,以及软件发展呈现WEB化的趋势,这给高校机房管理者提出了更高的要求。文章以机房管理人员的角度,根据日常管理中遇到的远程控制不方便、病毒查找困难、突发情况难以处理及半手工化操作落后并效率低等问题,设计并实现了无需客户端支持的基于B/S模式的机房运行支撑平台,管理人员可以实时随地利用PC终端或移动手持设备借助该平台,实时地进行机房远程监控和管理,提高机房管理效率及应急能力。