Boundary-based object segmentation in X-ray imaging using spiral search

In this paper, we propose a boundary-based method for object segmentation by using only the edge information. The proposed method is especially applied to object segmentation of dangerous firearms and knives in the X-ray images of baggage, where no colour or texture features are available to describe the target object. The Canny edge detector is used to extract edge points from the X-ray image. These edges have cluttered backgrounds and may be discontinuous. A fast spiral search is proposed to connect neighbouring points, either continuous or discontinuous, and form closed contours for individual objects. The distance and direction angle of an edge point in the search process can be obtained from a pre-constructed spiral look-up-table. No computation of the geometric features is required. Thus, the search of the coherent neighbouring points for edge connection is very fast. The experimental results have shown that the proposed method can effectively and efficiently segment a variety of firearms and knives of different shapes and sizes in the X-ray images of baggage.     

Continuous penetration depth computation for rigid models using dynamic Minkowski sums

We present a novel, real-time algorithm for computing the continuous penetration depth (CPD) between two interpenetrating rigid models bounded by triangle meshes. Our algorithm guarantees gradient continuity for the penetration depth (PD) results, unlike conventional penetration depth (PD) algorithms that may have directional discontinuity due to the Euclidean projection operator involved with PD computation. Moreover, unlike prior CPD algorithms, our algorithm is able to handle an orientation change in the underlying model and deal with a topologically-complicated model with holes. Given two intersecting models, we interpolate tangent planes continuously on the boundary of the Minkowski sums between the models and find the closest point on the boundary using Phong projection. Given the high complexity of computing the Minkowski sums for polygonal models in 3D, our algorithm estimates a solution subspace for CPD and dynamically constructs and updates the Minkowski sums only locally in the subspace. We implemented our algorithm on a standard PC platform and tested its performance in terms of speed and continuity using various benchmarks of complicated rigid models, and demonstrated that our algorithm can compute CPD for general polygonal models consisting of tens of thousands of triangles with a hole in a few milli-seconds while guaranteeing the continuity of PD gradient. Moreover, our algorithm can compute more optimal PD values than a state-of-the-art PD algorithm due to the dynamic Minkowski sum computation.     

从广播网络化到网络化广播的发展探讨

本文主要针对广播的发展状况,探讨广播从广播网络化到网络化广播的一些发展变化.主要介绍了如何会产生这些变化,以及网络化广播的特点和优势.使人们认识到网络与广播之间密不可分的关系,以及今后网络化广播发展的方向.     

一种二线制无极性数字称重传感器

现有的数字传感器至少由2根数据线和2根电源线共4根线组成,每根线均有明确的分工和极性,不能接错和短路,否则易损坏设备,需专业人员才能安装和维护;数据传输加密方式有限,易破解。利用本公司研发的"智能终端整机供电用二线制数据/电源共线传输装置及方法",将数字传感器的连线减至2根,且无极性、可短路,简化了系统的连接,提高系统的可靠性,使安装和维护变得极为简便。数据传输采用特殊的加密方式,极难破解。     

A novel fault detection method for VSC-HVDC transmission system of offshore wind farm

VSC-HVDC transmission system is going to become the most economical way of power delivery for large and remote offshore wind farms. An accurate and fast fault detection method is necessary to protect sensitive devices of these systems and maintain uninterrupted power delivery. This paper investigates an innovative technique for recognizing DC zone faults including HVDC cable faults and unbalancing of DC capacitor bank. Sheath voltage is presented as a novel criterion for detecting abnormal situations in the system. Transient voltage of cable sheath and Wavelet transform are used to identify different types of DC faults. Extensive simulation examples are performed on EMTDC–PSCAD platform and post-processed using MATLAB. The results illustrate that the proposed technique gives a robust performance and can be applied to protection scheme of offshore wind farms.     

A new method to rapidly detect rusty grain beetle,Cryptolestes ferrugineus (Stephens), in stored grain

Information on insect infestation inside stored grain bulks is required for safe grain storage. A new method to rapidly detect both adults and larvae of Cryptolestes ferrugineus (Stephens) in grain was developed based on the principle of microwave heating and insect behaviour under elevated temperature. The designed apparatus and processing procedure were tested to extract both the adults and larvae inside wheat with 14%, 16% and 18% moisture contents by using a domestic microwave oven (referred to as the microwave method). The recovery percentage of the introduced insects associated with the microwave method was compared with that of the Berlese funnel method (810 cm³ wheat in a funnel under an incandescent light bulb). The microwave method recovered 97.8% of introduced adults, while 90.6% of adults were recovered by the Berlese funnel method. The recovery percentage of the larvae inside marked wheat kernels was 83.3 ± 3.3% with the microwave method and less than 27% with the Berlese funnel method. There was no significant difference in extraction percentage between old and young larvae when the microwave method was used. The moisture content of the treated grain did not significantly influence the extraction percentage of the pest insect. The total processing time of the microwave method was less than 30 min compared to 6 h required for the Berlese funnel method.     

Small oscillation fault detection for a class of nonlinear systems with output measurements using deterministic learning

Early detection of small faults is an important issue in the literature of fault diagnosis. In this paper, for a class of nonlinear systems with output measurements, an approach for rapid detection of small oscillation faults is presented. Firstly, locally accurate approximations of unknown system dynamics and fault functions are achieved by combining a high gain observer and a deterministic learning (DL) theory. The obtained knowledge of system dynamics for both normal and fault modes is stored in constant RBF networks. Secondly, a bank of dynamical estimators are constructed for all the normal mode and oscillation faults. The knowledge obtained through DL is reused with a nonhigh-gain design. The occurrence of a fault can be detected if one of residual norms of a fault estimator becomes smaller than that of the normal estimator in a finite time. A rigorous analysis of the detectability properties of the proposed fault detection scheme is also given, which includes the fault detectability condition and the fault detection time. The attractions of the paper lie in that with output measurements, the knowledge of modeling uncertainty and nonlinear faults is obtained and then is utilized to enhance the sensitivity to small faults.     

基于 GIS 的"多规合一"辅助决策系统研究与应用

建立基于 GIS的"多规合一"辅助决策系统是"多规合一"信息化建设工作的一项重要工作,也是"多规合一"成果落实应用的具体体现. 本文提出利用GIS技术,以ArcGIS为开发平台,结合REST和SOA的WCF架构,构建一个"多规合一"辅助决策系统. 该系统的关键技术已应用于宁夏回族自治区"三规合一"及"多规融合"信息化平台的建设,取得较好的实际效果.     

论“新常态”下交通运输企业科技创新活力

近些年,交通运输领域虽然在发展方式逐步由粗放型转化为高效率、低成本、可持续的发展模式中有较大改进,但是科技在转变经济发展方式和调整经济结构中的支撑引领作用体现得还不明显,企业科技创新仍然存在未能有较大科技突破、严重依赖政府、创新能力和动力不足的现实情况,公平、公正、公开的科技市场和科技管理体系还未真正形成。本文从交通运输行业的特性分析入手,分析了交通运输传统企业科技研发的现状与困境,提出在"新常态"下对科技企业的新要求,并用信息化作为例子说明如何突破行业的自我封闭状态,并提出激发交通运输企业科技创新的措施建议。     

Conventional and less conventional mechanisms of professionalisation underpinning knowledge-intensive activities: the case of design in food industries

Professions are not only primary targets of institutional change, but also key contributors to innovation processes. By focusing on how the knowledge needed in support of innovation is professionalised and reaches accepted modes of organising work, the paper examines the interplay between the emergence of a new professional domain and the institutional dynamics of the industry(ies) within which professionals operate. To this aim, we propose a reflection on the mechanisms that underpin the professionalisation of design activities in food industries. Empirical evidence draws attention to those practices that allow knowledge originated in different contexts to be socialised and converge towards the same institutional umbrella, that is, a new professional domain. The degree to which such professionalisation resonates with extant professions literature is discussed.