Discovery of a variable broad absorption line in the BL Lac object PKS B0138-097

We report the discovery of a broad absorption line （BAL） of - 10^4 km s^-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as an Mg II BAL. This is the first detection of a BAL, which is sometimes seen in powerful quasars with high accretion rates, in a BL Lac object. The BAL was clearly detected in its spectra spanning two epochs at a high luminosity state taken in the Sloan Digital Sky Survey （SDSS）, while it disappeared in three SDSS spectra taken at a low luminosity state. The BAL and its variability pattern were also found in its historical multi-epoch spectra in the literature, but have been overlooked previously. In its high resolution radio maps, PKS 0138-097 shows a core plus a one- sided parsec-scale jet. The BAL variability can be interpreted as follows： The optical emission is dominated by the core in a high state and by the jet in a low state and the BAL material is located between the core and jet so that the BAL appears only when the core is shining. Our discovery suggests that outflows may also be produced in active galactic nuclei at a low accreting state.

Conversion of Object Oriented System into Software Product Line with Delta Modeling Abstract Behavioral Specification

This article contains a system conversion from object oriented design into Software Product Line (SPL) using delta modeling of Abstract Behavioral Specification (ABS). ABS is a modeling language which targets system with high level of variety and supports SPL development with delta modeling. The case study of this thesis is a digital library system called Library Automation and Digital Archive (LONTAR). Originally, LONTAR only uses SOAP-based web service. With ABS, LONTAR will be converted into SPL and implement another web service called REST. The motivation of this conversion of LONTAR from object oriented into SPL is because it is easier to develop system with ABS than using regular object oriented. Product definition in ABS is relatively easier than creating a new subclass and do customization to make it works well.

3D reconstruction of complex curved objects from line drawings

An active research topic in computer vision and graphics is developing algorithms that can reconstruct the 3D surface of curved objects from line drawings. There are a number of algorithms have been dedicated to solve this problem, but they can＇t solve this problem when the geometric structure of a curved object becomes complex. This paper proposes a novel approach to reconstructing a complex curved 3D object from single 2D line drawings. Our approach has three steps： （1） decomposing a complex line drawing into several simpler line drawings and transforming them into polyhedron; （2） reconstructing the 3D wireframe of curved object from these simpler line drawings and generating the curved faces; （3） combining the 3D objects into the complete objects. A number of examples are given to demonstrate the ability of our approach to successfully perform reconstruction of curved objects which are more complex than previous methods.

Labeling Line Drawings with Hidden-Part-Drawn of Planar Object with Trihedral Vertices

Although line drawings consist of only line segments on a plane, they convey much information about the three-dimensional object structures. For a computer interpreting line drawings, some intelligent mechanism is required to extract three-dimensional information from the two-dimensional line drawings. In this paper, a new labeling theory and method are proposed for the two-dimensional line drawing with hidden-part-draw of a three-dimensional planar object with trihedral vertices. Some rules for labeling line drawing are established. There are 24 kinds of possible junctions for line drawing with hidden-part-draw, in which there are 8 possible Y and 16 W junctions. The three problems are solved that Sugihara＇s line drawing labeling technique exists. By analyzing the projections of the holes in manifold planar object, we have put forward a labeling method for the line drawing. Our labeling theory and method can discriminate between correct and incorrect hidden-part-draw natural line drawings. The hidden-part-draw natural line drawings can be labeled correctly by our labeling theory and method, whereas the labeling theory of Sugihara can only label the hidden-part-draw unnatural line drawings in which some visible lines must be drawn as hidden lines, and some invisible lines must be drawn as continuous lines.

Recovering the Shape of Planar Object Depicted by a Line Drawing under Axonometric Projection

A new approach is proposed for automatically creating B-rep models of a three-dimensional planar object from a line drawing depicting the object under orthographically axonometric projection. A new line parameterization that satisfies the uniqueness, boundedness and uniformness for representing lines in 2D and 3D space is given. According to the location relation between lines and planes of object depicted by the line drawing, some constraints about object’s 3D information are produced and a linear system based on those constraints is established. 3D information of a planar body can be obtained by solving the linear system. It is proved that, during the processing, there existed at least four degrees of freedom. It is more convenient to use information about lines and planes instead of points and planes for computer vision and intelligent CAD systems to interpret line drawings of planar objects.

Locating the position of objects in non-line-of-sight based on time delay estimation

Non-line-of-sight imaging detection is to detect hidden objects by indirect light and intermediary surface（diffuser）.It has very important significance in indirect access to an object or dangerous object detection, such as medical treatment and rescue. An approach to locating the positions of hidden objects is proposed based on time delay estimation. The time delays between the received signals and the source signal can be obtained by correlation analysis, and then the positions of hidden objects will be located. Compared with earlier systems and methods, the proposed approach has some modifications and provides significant improvements, such as quick data acquisition, simple system structure and low cost, and can locate the positions of hidden objects as well： this technology lays a good foundation for developing a practical system that can be used in real applications.

Efficient Object Localization Scheme Based on Vanishing Line in Road Image for Autonomous Vehicles

This paper proposes an efficient object localization method based on a vanishing line. The proposed method can be much improved in time efficiency since it requires scanning only vanishing line area. It requires the time complexity of O(n) while the existing sliding window method requires the time complexity O(n2) for detecting all objects in the entire image. In addition, the range of detection area can be also remarkably reduced when compared with the sliding window method. As a result, the total range and times for searching in the proposed method can be significantly reduced by considering together the distance and position of the object. The experiment on the proposed method is performed with the virtual road data set known as SYNTHIA, and the competitive results are obtained.

线截抽样(LIS-Line Intersect Sampling)与线状物体(林网、路网)调查原理研究

以Ｂｕｆｏｎ随机投针问题为原理，对线截抽样的概念作了系统的介绍，并在此基础上提出了以线截抽样为原理的线状物体的调查方法。在计算机上成功地模拟了路网调查，从模拟的几种方案可以得出：线截抽样完全适用路网调查，且以本文中的Ｂ、Ｃ两种方案为好，并可以以此推广到林网及防护带的调查。

基于粒子滤波的on-line boosting目标跟踪算法

基于Haar-like特征的on-line boosting跟踪算法(HBT)把目标跟踪看作是目标与背景的二分类问题,通过在候选区域搜索最大分类置信度的方法得到目标新的位置。但在获取最大置信度时选用的是区域穷举搜索法,当目标过大或者运动速度过快时,很难确保系统的实时性,且易造成跟踪丢失。本文将粒子滤波算法引入HBT目标跟踪框架中,通过建立目标运动模型,并把HBT目标分类置信度与粒子滤波的观测模型结合起来,提出了基于粒子滤波的on-line boosting目标跟踪算法(PFHBT)。与HBT算法相比,本文算法不仅加快了计算速度,而且很好地解决了目标速度过快造成跟踪丢失的问题,保证了系统的实时性和鲁棒性。

The Four Intersection-and-Difference Model for Line-Line Topological Relations

The description of line-line topological relations is still an unsolved issue although much effort has been done. The problem is involved in many practical applications such as spatial query, spatial analysis and cartographic generalization. To develop a sound and effective approach to describe line-line relations, it is first necessary to define the topology of an individual line, i.e., local topology. The concept of connective degree is used for the identification of topological differences in the geometric structure of a line. The general topological definition of a line is given, i.e., endpoints set and interior point set. This definition can be applied to the embedded spaces of different dimensions, whether co-dimension is equal to or larger than zero. On this basis, a generic model called the 4 intersection-and-difference is set up for the description of basic line-line topological relations, upon which a conceptual neighborhood graph is built with consideration of topological distance, it is concluded that the proposed model can represent the property of topological changes, and basic relations between line segments in IR^1 and IR^2.

EDLine与改进光流法线路异物智能检测

为提高无人机电力故障巡检效率,提出一种结合边缘绘制线(edge drawing line,EDLine)特征提取算法与改进光流法的输电线路异物智能检测方法。鉴于背景纹理对航拍图像的影响,研究一种基于矩阵的线段融合算法以解决EDLine线段检测的断续问题,根据多特征约束提取输电线路区域。为有效识别异物,利用动量因子改进光流算法迭代收敛速度,根据光流信息检测异物故障。对无人机巡检图像的测试结果表明,该方法在复杂背景或异物不明显时均可有效检测出异物。提出检测算法准确度高、鲁棒性强,保证巡检的时效性。

On the emission lines in active galactic nuclei with relativistic jets

The effect of the observed continuum emitted from a relativistic jet on the measurement of the full width at half maximum （FWHM） of an emission line is analyzed. If the jet contribution is not properly subtracted, the FWHM of the line could seem narrower than it should. The cases of an emission line detected in BL Lac objects and γ-ray Narrow-Line Seyfert 1 galaxies （γ-NLS1s） are addressed. It is shown that the smallness of the observed FWHM of the Lyα lines detected in three well-known BL Lacs is an effect due to the combined action of both the relativistic jet and a weak accretion disk. Once the Doppler boosting effect of the jet continuum is removed, the intrinsic FWHM values of the lines are found to be in the usual range. By contrast, the narrow permitted lines in γ-NLS1s are really narrow, since the disk and the lines are much more powerful. This also confirms that γ-NLS1 is really a new class of γ-ray emitting AGN, different from blazars and radio galaxies.

面向流程制造的数字孪生车间可视化监控系统研究

为了解决流程制造过程监控实时性差、准确性不足的问题,在数字孪生技术迅速发展且与制造业结合愈发紧密的背景下,提出基于生产要素数据、生产工艺流程与多工序设备实体对象的数字孪生车间可视化监控系统架构。从要素、状态、运行逻辑等多个维度对多工序耦合生产线实体对象进行孪生建模,基于OPC UA统一架构的数据采集传输,虚拟车间的实时驱动等关键技术,实现了流程制造设备状态、生产要素工艺全流程三维可视化监控。基于某流程制造企业制丝生产试验线开展了应用验证,为提升流程制造过程中全生产要素的预见性、联动性、自治性提供了方法和实现途径。

Exploring Local Regularities for 3D Object Recognition

In order to find better simplicity measurements for 3D object recognition, a new set of local regularities is developed and tested in a stepwise 3D reconstruction method, including localized minimizing standard deviation of angles（L-MSDA）, localized minimizing standard deviation of segment magnitudes（L-MSDSM）, localized minimum standard deviation of areas of child faces （L-MSDAF）, localized minimum sum of segment magnitudes of common edges （L-MSSM）, and localized minimum sum of areas of child face （L-MSAF）. Based on their effectiveness measurements in terms of form and size distortions, it is found that when two local regularities： L-MSDA and L-MSDSM are combined together, they can produce better performance. In addition, the best weightings for them to work together are identified as 10% for L-MSDSM and 90% for L-MSDA. The test results show that the combined usage of L-MSDA and L-MSDSM with identified weightings has a potential to be applied in other optimization based 3D recognition methods to improve their efficacy and robustness.

Constructing the Virtual Production Line

In order to study the constructing technology of virtual production line, the structure model of virtual production line was presented, and the object oriented technique was used to establish its basic classes and relevant models, including solid model, behavior model and object oriented Petri net based control model, and based on this, the constructing of virtual production line was realized. The application proved that the virtual production line had many good characteristics, such as visualization, interaction, multi layer and reusability, and it's an efficient tool of analyzing and modeling for layout planning and rapidly reconfiguring of production line.

融合多尺度特征的YOLOv8裂缝缺陷检测算法

针对井壁裂缝背景复杂,纵横比差异大,导致检测效率低、漏检等问题,提出了一种融合多尺度特征的裂缝缺陷检测模型EDG-YOLO。设计特征提取模块EIRBlock(efficient inverted residual block),并构建C2fEIR增强主干网络对井壁浅层裂缝特征信息的提取能力。在颈部融合CSP_EDRAN(CSP efficient dilated reparam aggregation network)实现对裂缝特征信息的复用,促进浅层与深层语义信息之间的交互。嵌入DAM(dual attention module)注意力机制,增强井壁裂缝特征的表达能力。构建轻量级检测头GDetect,借助GSConv模块进一步轻量化网络。在自制井壁裂缝数据集上的实验结果表明,与YOLOv8相比,EDG-YOLO的平均检测精度达到87.4%,提高了2.3个百分点,模型的参数量和计算量分别降低了33%和47%,单幅图像推理时间为13.2 ms,满足井下场景的实时检测需求。

改进YOLOv7的输电线路变尺度目标检测

针对输电线路无人机巡检图像中小目标检测精度低下的问题,提出一种改进型YOLOv7的输电线路变尺度多目标的检测方案。方案首次将基于YOLO7的目标检测模型应用到输电线路目标检测中,引入Transformer注意力工作机制,使用g^(n)Conv代替高效聚合网络中的卷积层提取巡检图像特征,经过RFPN网络将不同分辨率特征进行融合后,分别进行不同尺度目标的预测,提高对小目标的检测精度,达到了93.68%的平均检测精度,也可以检测到被遮挡的目标,具有一定的泛化能力。结果表明,上述模型能够有效检测出巡检图像中的防震锤和绝缘子,为后续故障诊断提供了理论依据。

汽车整车多级生产线协同排序优化方法

为满足汽车整车生产线不同工艺车间对车身序列的不同需求,提高汽车生产线多工艺车间的协同生产能力并降低生产成本,提出一种面向汽车整车多级生产线的协同排序优化方法。分析了汽车生产过程中不同工艺车间对车身序列的不同需求,在考虑焊接车间车型更换次数、涂装车间颜色更换次数、总装车间总超载和空闲时间、总装车间物料消耗均衡等传统优化目标的基础上,搭建了缓冲区重排序成本的目标函数,并以此构建了汽车整车多级生产线协同排序多目标优化模型,然后采用基于启发式出入站规则的第三代非支配排序遗传算法对模型进行优化求解。最后通过某公司的实际生产案例,验证了所提模型和方法的有效性。

面向水土生态系统服务协同的土地利用模拟

针对水土生态系统服务功能的相关成果难以应用到实际土地利用规划中的问题。本研究以黄土高原为研究区,使用K-means聚类算法在小流域尺度上划分土地利用结构,结合InVEST模型探究土地利用结构对水土生态系统服务功能的影响。以阳泉市为典型区,设置多情景,结合多目标优化算法和PLUS模型进行未来土地利用模拟。结果表明:在小流域尺度上,黄土高原的土地利用结构可以划分为6类。农地结构、林地结构、农地-草地结构、草地结构、农地-林地-草地结构、裸地结构,最优土地利用占比分别是0.6—0.7,0.5,0.45/0.4(农地/草地),0.75—0.85,0.15/0.4/0.25—0.35(农地/林地/草地)。各土地利用结构中生态系统服务之间的约束曲线基本上是驼峰型、凹波、半凹波和凸波。从未来的土地利用数量上看,3种情景下水域和灌木面积均处于较低水平。其中,对照情景中城建用地面积最大,基准情景次之,协同情景最小。3种情景下,阳泉市均以城市建设为中心,向外依次为耕地、草地和林地的层次分布特征。土地利用的发展过程中各种土地类型之间存在替代规律,即城市建设倾向于取代耕地和草地,草地则可能取代林地和耕地,而林地则可能与草地发生替代关系。研究成果对黄土高原土地利用规划有重要参考价值。

基于多重注意力和特征对齐的销钉缺陷检测方法

电网规模的快速扩张对输电线路的检测维护提出更高的要求,智能高效的自动化电力巡检图像识别算法作为提高检测维护的手段,已经成为目前研究的重要方向之一。为实现巡检图像中销钉缺陷目标的准确识别,文章提出一种基于多重注意力和特征对齐的销钉缺陷检测方法。首先,构建基于可变形注意力的可变形检测变压器(deformable detection transformer,Deformable-DETR)框架,解决现有识别算法中无法通过卷积神经网络进行像素点轮廓-环境关系建模的问题;之后,提出区域注意力特征提取模块,解决由可变形注意力带来的特征粒度不足的问题;为丰富目标物体特征质量,提出基于注意力的候选框特征对齐模块和约束函数;最后,选取华中地区某电力公司的航拍图像数据验证算法性能。结果表明,所提算法总体性能相比于现有的卷积算法提升5.4%,总体平均检测精度达到90.5%。