Effective input order of dynamics learning tree

In this paper, we discuss about the learning performance of dynamics learning tree (DLT) while mainly focusing on the implementation on robot arms. We propose an input-order-designing method for DLT. DLT has been applied to the modeling of boat, vehicle, and humanoid robot. However, the relationship between the input order and the performance of DLT has not been investigated. In the proposed method, a developer is able to design an effective input order intuitively. The proposed method was validated in the model learning tasks on a simulated robot manipulator, a real robot manipulator, and a simulated vehicle. The first/second manipulator was equipped with flexible arm/finger joints that made uncertainty around the trajectories of manipulated objects. In all of the cases, the proposed method improved the performance of DLT.     

Multi-objective method for divisible load scheduling in multi-level tree network

There is extensive literature concerning the divisible load theory. Based on the divisible load theory (DLT) the load can be divided into some arbitrary independent parts, in which each part can be processed independently by a processor. The divisible load theory has also been examined on the processors that cheat the algorithm, i.e., the processors do not report their true computation rates. According to the literature, if the processors do not report their true computation rates, the divisible load scheduling model fails to achieve its optimal performance. This paper focuses on the divisible load scheduling, where the processors cheat the algorithm. In this paper, a multi-objective method for divisible load scheduling is proposed. The goal is to improve the performance of the divisible load scheduling when the processors cheat the algorithm. The proposed method has been examined on several function approximation problems. The experimental results indicate the proposed method has approximately 66% decrease in finish time in the best case.     

Do you need a blockchain in construction? Use case categories and decision framework for DLT design options

Blockchain and other forms of Distributed Ledger Technology (DLT) provide an opportunity to integrate digital information, management, and contracts to increase trust and collaboration within the construction industry. DLT enables direct peer-to-peer transactions of value across a distributed network by providing an immutable and transparent record of these transactions. Furthermore, there is potential for business process optimization and automation on the transaction level through the use of smart contracts, which are code protocols deployed on supported DLT systems. However, DLT research in the construction industry remains at a theoretical level; there have been few implementation case studies to date. One potential reason for this is a knowledge gap between use-case ideas and the DLT technical system implementation. This paper aims to reduce this gap by (1) reviewing and categorizing proposed DLT use cases in construction literature, (2) providing an overview of DLT and its design options, (3) proposing an integrated framework to match DLT design options with desired characteristics of a use case, and (4) analysing the use cases using the new framework. Together, the use case categories and proposed decision framework can guide future implementers toward more connected and structured thinking between the technological properties of DLT and use cases in construction.     

一种基于DLT模型和圆环点改正的摄像机定标方法

提出一种基于DLT(直接线性变换)模型和圆环点改正的摄像机定标方法.运用计算机视觉原理,通过三维DLT平面模板模型平移对摄像机进行定标,并在模板上设计一个圆环,使用圆环上的点进行定标参数改进.实验数据证明,定标方法是有效的.     

混合系统建模理论与混合系统模型

在现代工程仿真中,大部分仿真对象表现出同时具有连续和离散对象的特征,利用现有的离散或者连续建模理论不能全面的反应出对象特性,需要对混合系统的建模进行相应的理论研究.从系统理论出发,围绕着系统的连续属性和离散属性,以及他们对系统信息的响应,还有他们之间的相互作用为中心,建立混合系统模型的形式化表达和系统理论基础,并在此基础上建立了混合系统模型.以此模型为基础,在实践中为某大型仿真项目中的工程对象建立了混合模型,在仿真中得到有效的应用.     

Handling large-size discrete wavelet transform on network-based computing systems — parallelization via divisible load paradigm

The discrete wavelet transform (DWT) is a powerful signal processing tool, but comes with a considerable computation cost. In this paper, we consider the problem of parallelizing the DWT computation on loosely-coupled networked systems. We first systematically analyze the data dependencies among DWT computations, identify the partitionable portions and then by applying the divisible load theory (DLT), we derive a novel scheduling strategy to schedule DWT computation onto bus networks. Our study is first of its kind in the DLT literature to demonstrate handling a highly coupled recursive computational nature of this problem towards gaining a significant speed-up.     

模糊定性仿真理论研究与算法实现

针对纯定性仿真方法的缺陷,通过采用模糊集、作者对定性仿真的模糊构造、仿真机制、算法等方面做了研究;在此基础上,开发了一个模糊定性建模与仿真的软件环境,实现了模糊构造、模型转换、仿真算法到结果输出等主要功能,并分析了一个简单的实例。     

Screw-based kinematic modeling and geometric analysis of planar mobile robots

Typical mobile robots can be modeled as parallel mechanisms by employing an interfacing variable between the ground and the wheels. Based on this conception, the screw theory was employed in the following work as an alternative approach in the modeling of such parallel-natured mobile robots. This theory allows for a geometric analysis of mobile mechanisms. As a result, the computational load in the derivation of a Jacobian model can be reduced, the kinematic model for different sets of inputs can be easily obtained, and an equivalent serial-chain model can be analyzed. Two mobile robots were examined as exemplary models. The proposed approach can also be applied to kinematic modeling and the analysis of general types of mobile robots.     

Simulation study on the security of consensus algorithms in DAG-based distributed ledger

Due to the advantages of high volume of transactions and low resource consumption, Directed Acyclic Graph (DAG)-based Distributed Ledger Technology (DLT) has been considered a possible next-generation alternative to block-chain. However, the security of the DAG-based system has yet to be comprehensively understood. Aiming at verifying and evaluating the security of DAG-based DLT, we develop a Multi-Agent based IOTA Simulation platform called MAIOTASim. In MAIOTASim, we model honest and malicious nodes and simulate the configurable network environment, including network topology and delay. The double-spending attack is a particular security issue related to DLT. We perform the security verification of the consensus algorithms under multiple double-spending attack strategies. Our simulations show that the consensus algorithms can resist the parasite chain attack and partially resist the splitting attack, but they are ineffective under the large weight attack. We take the cumulative weight difference of transactions as the evaluation criterion and analyze the effect of different consensus algorithms with parameters under each attack strategy. Besides, MAIOTASim enables users to perform large-scale simulations with multiple nodes and tens of thousands of transactions more efficiently than state-of-the-art ones.     

汉语统计语言模型训练样本容量的定量化度量

统计语言模型的参数训练是语言建模的关键,选择多大的训练样本就能够达到建模的参数估计误差要求,是语言建模理论关心的问题之一。应用数理统计理论对汉语统计语言模型的训练语料样本容量进行了定量化描述,给出了汉语n-gram模型训练样本容量下界的估算方法及量化估算公式,可根据模型参数估计的误差要求计算出模型训练所需的样本容量。     

一种基于Kalman滤波器的自适应背景建模改进算法

基于传统Kalman滤波器理论的背景建模方法,不能很好地解决目标缓慢运动导致背景模型出现拖影的问题。针对该问题,提出了一种结合Kalman滤波器理论与动态区域重构的自适应背景建模改进算法,介绍了Kalman滤波器理论主要思想和改进算法的方法流程与效果。与传统的Kalman背景建模相比,该方法在增加少量计算复杂度的前提下,较好地解决了目标缓慢运动导致背景模型出现拖影的问题,同时也能较好地消除背景噪声。通过对图像序列的仿真实验证明:该方法具有很好的实用性与鲁棒性。     

一种改进的用例建模方法及其在电子政务中的应用

用例建模作为一种需求建模方法受到广泛的关注和应用。文章总结了用例建模方法的优点和不足,针对其局限性给出了相应的解决方案,提出了用例建模的改进方法。该方法将传统需求分析思路与用例建模方法有效融合,将分解模式转移至角色模型避免了功能分解,并解决了前置条件降低有效性验证的问题,同时利用可视化建模提高系统模型的易理解性。文章采用改进的用例建模方法对电子文件审批系统进行了需求分析和模型设计,该改进后的用例建模方法可以同时满足用户获取系统价值和引导开发人员系统开发的两方面需求。     

A regulatory control framework for decentrally governed DLT systems: Action design research

Although distributed ledger technology (DLT) systems seem to address conventional regulatory governance concerns, they also present systemic risks. This paper aims to address the risks of decentrally governed DLT systems. It achieves this by identifying regulatory controls that address the altered governance dynamics of decentralized systems. To address the research gap in DLT regulation, we co-designed regulatory control treatments with Australian regulatory DLT experts using a participatory action design research approach. This paper provides a theory-ingrained, practitioner-vetted framework to inform regulators, regulated entities and researchers of appropriate control responses to systemic and participant risks presented by decentrally governed DLT systems.     

云环境下图数据库建模技术及其应用研究

针对云环境下传统关系型数据库在大数据库建模方面存在的诸多问题,描述了一种全新的能适应云计算环境建模的图数据库,定义了图数据库模型的基本概念,给出了图数据库建模元素及组织形式,在关系型数据库概念模型建模理论及方法的基础上提出了图数据库建模的若干规则和方法。以图数据库Neo4j为例,详细描述了现代物料入库管理图数据库的建模过程,并应用Cypher语言实现该系统模型的增加、删除、更改、查询及统计功能。实践结果表明：利用图数据库建模技术构造的模型具有语义表达更丰富、更具简易性和可扩展性等优点,对开发基于图模型的智能管理信息系统能够提供一定的参考依据。     

一种数据模型的范畴论建模方法

针对数据模型复杂语义建模的应用需求, 以及目前数据模型范畴论建模方法理论研究与工程实践方面存在的不足, 建立了一种素描数据模型。该模型在模型范畴的形式化框架内, 用与特定数据库建模语言无关的范畴论对数据库状态的一致性转换进行了形式化描述, 扩展了传统ER模型的表示与处理功能。基于素描对图形化建模规范的支持, 设计了ER模型向素描数据模型转换的算法, 以精确的语义联系保证模型转换的语义完整性, 并通过实验与对比分析了素描数据模型与算法的优势, 为数据模型的范畴论建模方法研究提供便利、高效的形式化理论框架。     

分形理论在分队作战系统建模中的应用

如何体现现代作战环境中开放性、对称与自相似性、非平衡态有序性等复杂特性是当前作战系统建模的一个难点问题.源于几何学的分形理论拓宽了人们的思路,使人们认识到可以将分形理论引入到作战系统建模中以解决这种复杂情况.因此,本文基于分形理论,创新性的提出分形分队的概念,并对其理论依据,分形空间和分形维数等相关概念进行了论述.在此基础上,以某多兵种合成分队的建模为例,给出了基于分形理论的分队作战系统模型构建的一般过程.     

基于作战环的作战体系节点重要度评估

以实际作战体系为研究对象, 以复杂网络理论和现代作战循环理论为理论基础对作战体系的建模和评估方法进行研究, 首先提出一种基于功能作战模型的IDFCS (investigation, decision, fire, communication, and support)作战体系建模方法及该模型的生成算法, 从更贴近实际、更为精细的角度对体系节点的能力和作战体系规律进行定量描述; 其次根据作战环理论提出基于IDFCS模型的体系效能评估方法和节点重要度评估方法, 充分利用节点能力属性对作战体系效能进行定量分析; 最后利用提出的模型生成算法生成不同规模的作战体系样本网络, 并对其进行效能评估, 为针对体系作战的进一步深入研究提供理论支撑.     

基于ADAMS的多刚体动力学简化建模与仿真

摘 要：应用多刚体动力学理论在 ADAMS 软件中对复杂模型进行简化建模与仿真,解决 复杂模型在 ADAMS 中建模过程繁琐、仿真过程计算效率低等问题。首先对简化建模方法的多 刚体动力学理论进行了分析;然后提出了基于 ADAMS 简化建模的具体方法,着重研究了使原 模型和简化模型中心主转动惯量、中心惯量主轴连体基方向相同的数学方法;最后,将该简化 建模方法应用到过山车单车模型上,并对仿真结果进行对比分析。结果显示基于 ADAMS 的多 刚体动力学简化过山车模型与原模型的仿真效果基本相同。该简化建模方法能有效提高复杂模 型在 ADAMS 中的建模效率和仿真的计算效率。     

Exploring interoperability of distributed Ledger and Decentralized Technology adoption in virtual enterprises

The breakthrough of Distributed Ledger Technologies (DLT) has enabled the emergence and implementation of a wide range of digital platforms in Virtual Enterprises (VE) which collaborate to provide digital services. DLT has the potential to revolutionize VE by offering transparent, decentralized, trustworthy, data provenance, reliable, and auditable features. Yet, the full deployment of DLT systems and digital platforms is still limited since some systems are operating in isolation. Hence, DLT interoperability is one of the challenges inhibiting widespread adoption of DLT platforms. DLT interoperability represents the ability for one distributed ledger platform to interact and share data with other legacy digital applications. It is inevitable to orchestrate these digital platforms fragments by introducing a cross-DLT platform integration to govern data usage within VE. Presently, already proposed approaches for DLT interoperability such as naive relay, sidechain, oracle solutions notary scheme, or relay chain are mostly not employed as they are either resource-intensive or too expensive to operate. Therefore, this paper presents a layered architecture that aids interoperability of DLT, and digital platforms based on IOTA Tangle. Design science method is adopted, and case demonstration is carried out to show how IOTA Tangle enable VE to provide an innovative virtual asset payment platform for seamless electric mobility as a service to clients. IOTA was employed as the DLT platform due to its data traceability, immutability, and tamper-proof features which allow for verification of integrity of data. IOTA offers flexibility and performance to support a reliable digital solution. Findings from this study presents a layered architecture that aids IOTA Tangle to make requests, inter-communicate, and share data via RESTful application programming interface as gateway with other external digital platforms deployed by VE to achieve an interoperable eco-system.