Search results for "soft"
showing 10 items of 9809 documents
Hard material small-batch industrial machining robot
2018
Abstract Hard materials can be cost effectively machined with standard industrial robots by enhancing current state-of-the-art technologies. It is demonstrated that even hard metals with specific robotics-optimised novel hard-metal tools can be machined by standard industrial robots with an improved position-control approach and enhanced compliance-control functions. It also shows that the novel strategies to compensate for elastic robot errors, based on models and advanced control, as well as the utilisation of new affordable sensors and human-machine interfaces, can considerably improve the robot performance and applicability of robots in machining tasks. In conjunction with the developme…
A model for torque losses in variable displacement axial piston motors
2018
This paper includes a comparison of earlier presented models for torque losses in hydraulic motors and several proposed models that all rely on data typically available for a system engineer. The new models and the old ones are compared. The new models are all based on a model developed by Jeong 2007 with an expansion that include variable displacement. All of the new models yield very good accuracy down to approximately 50% of maximum displacement and down to approximately 15% of maximum speed. In these operational ranges the deviation in torque is less than 1%. The main purpose of the new models is to facilitate simulations of hydraulically actuated winches with a balance between accuracy…
Aesthetic considerations for the min-max K-Windy Rural Postman Problem
2017
[EN] The aesthetic quality of routes is a feature of route planning that is of practical importance, but receives relatively little attention in the literature. Several practitioners have pointed out that the visual appeal of a proposed set of routes can have a strong influence on the willingness of a client to accept or reject a specific routing plan. While some work has analyzed algorithmic performance relative to traditional min-sum or min-max objective functions and aesthetic objective functions, we are not aware of any work that has considered a multi-objective approach. This work considers a multi-objective variant of the Min-Max K-Vehicles Windy Rural Postman Problem, discusses sever…
Heat Pump Induction Motor Faults Caused by Soft Starter Topology — Case Study
2021
This paper presents a case study of electrical machine faults, emerging in heat pump systems. In Nordic countries, heat pumps have been gaining popularity during the past years and have become one of the leading ways of heating in households and smaller public buildings. Although not a very complicated setup, the devices used are still prone to unexpected failures, especially if wrongly chosen, installed or maintained. The paper presents a study conducted on five real-life cases with very similar outcomes and failure modes. The setup of the systems is explained, faults are listed and presented, causes of the faults including modeling and measurement data are provided. The suggestions are gi…
Heuristics for the min–max arc crossing problem in graphs
2018
Abstract In this paper, we study the visualization of complex structures in the context of automatic graph drawing. Constructing geometric representations of combinatorial structures, such as networks or graphs, is a difficult task that requires an expert system. The automatic generation of drawings of graphs finds many applications from software engineering to social media. The objective of graph drawing expert systems is to generate layouts that are easy to read and understand. This main objective is achieved by solving several optimization problems. In this paper we focus on the most important one: reducing the number of arc crossings in the graph. This hard optimization problem has been…
Variable neighborhood descent for the incremental graph drawing
2017
Abstract Graphs are used to represent reality in several areas of knowledge. Drawings of graphs have many applications, from project scheduling to software diagrams. The main quality desired for drawings of graphs is readability, and crossing reduction is a fundamental aesthetic criterion for a good representation of a graph. In this paper we target the edge crossing reduction in the context of incremental graph drawing, in which we want to preserve the layout of a graph over successive drawings. We propose a hybrid method based on the GRASP (Greedy Randomized Adaptive Search Procedure) and VND (Variable Neighborhood Descent) methodologies and compare it with previous methods via simulation.
Improving the performance of embedded systems with variable neighborhood search
2017
Graphical abstractDisplay Omitted Embedded systems have become an essential part of our lives, mainly due to the evolution of technology in the last years. However, the power consumption of these devices is one of their most important drawbacks. It has been proven that an efficient use of the memory of the device also improves its energy performance. This work efficiently solves the dynamic memory allocation problem, which can be formally defined as follows: given a program that has to be executed by a circuit, the objective is to fit that program in memory in such a way that the computing time required to execute it is minimized. In this work, we propose a parallel variable neighborhood se…
DESDEO : An Open Framework for Interactive Multiobjective Optimization
2018
We introduce a framework for interactive multiobjective optimization methods called DESDEO released under an open source license. With the framework, we want to make interactive methods easily accessible to be applied in solving real-world problems. The framework follows an object-oriented software design paradigm, where functionalities have been divided to modular, self-contained components. The framework contains implementations of some interactive methods, but also components which can be utilized to implement more interactive methods and, thus, increase the applicability of the framework. To demonstrate how the framework can be used, we consider an example problem where the pollution of…
Survey of Cyber Threats in Air Traffic Control and Aircraft Communications Systems
2018
Air traffic control systems based on the ADS-B standard have been widely adopted in civil aviation to the point that they are now considered the de facto standard. ADS-B provides major benefits to airports and airlines by increasing the safety of air traffic management and control and allowing more flights to travel near busy airports. However, the ADS-B technology lacks sufficient security measures. The ADS-B system is vulnerable and exposed to cyberattacks. We survey the potential known threats and attacks against ADS-B and assess the potential cybersecurity threats to air traffic management and control. The widespread use of ADS-B and the lack of security features in it, i.e., all the AD…
Hypervisor Memory Introspection and Hypervisor Based Malware Honeypot
2020
Memory acquisition is a tool used in advanced forensics and malware analysis. Various methods of memory acquisition exist. Such solutions are ranging from tools based on dedicated hardware to software-only solutions. We proposed a hypervisor based memory acquisition tool. [22]. Our method supports ASLR and Modern operating systems which is an innovation compared to past methods [27, 36]. We extend the hypervisor assisted memory acquisition by adding mass storage device honeypots for the malware to cross and propose hiding the hypervisor using bluepill technology.