Physical Sciences and Mathematics Commons^™

Scatter Reduction By Exploiting Behaviour Of Convolutional Neural Networks In Frequency Domain, Carlos Ivan Jerez Gonzalez

Theses and Dissertations

In X-ray imaging, scattered radiation can produce a number of artifacts that greatly

undermine the image quality. There are hardware solutions, such as anti-scatter grids.

However, they are costly. A software-based solution is a better option because it is

cheaper and can achieve a higher scatter reduction. Most of the current software-based

approaches are model-based. The main issues with them are the lack of flexibility, expressivity, and the requirement of a model. In consideration of this, we decided to apply

Convolutional Neural Networks (CNNs), since they do not have any of the previously

mentioned issues.

In our approach we split …

Dynamic Characteristics Research Of Torsional Vibration Generator, Jialin Tian, Du Fan, Yonghao Zhu, Chuanhong Fu

Journal of System Simulation

Abstract: Aiming at poor drill ability and low rate of penetration during the drilling process, a torsional vibration generator is presented. The structure and the operational principle of the torsional vibration generator are analyzed according to the torsional theory. The relationships among the collision frequency,the amount of hydraulic hammer compression, the torque, the inlet pressure, and inlet flow are obtained on the basis of its dynamic model, which is established in light of the actual working condition. Compared with the example calculation, the experimental test verifies the accuracy and reliability of calculation method. The research results show that when the …

Analysis Of Gesture Frequency And Amplitude As A Function Of Personality In Virtual Agents, Alex Michael Rayon

Open Access Theses & Dissertations

Embodied conversational agents are changing the way humans interact with technology. Agents are expected to behave like people, both verbally and non-verbally. Researchers within the Human-Computer Interaction community have found many attributes of an agentâ??s gesture contribute to an agentâ??s perceived personality and believability.

Gesture amplitude and frequency are two of the attributes that contribute to the naturalness of a gesture. Currently, no previous studies have defined an empirical baseline for generating natural gestures for these two attributes. I seek to discover whether gesture amplitude and frequency affect how users perceive an agentâ??s naturalness, and which gestures would be preferred …

Modeling And Control Of A 6-Control-Area Interconnected Power System To Protect The Network Frequency Applying Different Controllers, Ngockhoat Nguyen, Qi Huang, Thi-Mai-Phuong Dao

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we first analyze and build a model of the 6-control-area interconnected power system as the typical case study. Subsequently, different frequency controllers based on tie-line bias control strategy, namely integral, proportional--integral, proportional--integral--derivative, and PI-based fuzzy logic, will be investigated and applied to the power system model. The most important control performances, such as overshoots and settling times, are considered in this study to evaluate the stability of the power system and choose the most suitable controller for maintaining the network frequency. The simulation results have been achieved by using MATLAB/Simulink package version 2013 in this work. According …

Impact Of Counterbalance Mass On Torsional Vibrations Of Crankshaft, Asllan Hajderi, Drakuli Lumi

UBT International Conference

In the present study is shown how to change the main indicators of vibrations of crankshaft, in case of changing its masses. In the study it was taken the crankshaft of diesel engine with 4 cylinders in line with 5 main journals. To study the torsional vibration of the crankshaft system, the first it is carried the construction of equivalent reduced scheme with five discs connected to four flexible shafts. Results show that the reduced inertia moments of disks for the case with counterbalances grow to 24%. Free frequency and vibration forms, is calculated by using Holxer-Tole method. Results show …

Concernlines: A Timeline View Of Co-Occurring Concerns, Christoph Treude, Margaret-Anne Storey

Research Collection School Of Computing and Information Systems

Understanding the evolution of a software system requires understanding how information about the release history, non-functional requirements and project milestones relates to functional requirements on the software components. This short paper describes a new tool, called CONCERNLINES, that supports this cognitive process by visualizing co-occurring concerns over time.

A New Approach For Anti-Aliasing Raster Data In Air Borne Imagery, Fahim Arif, Muhammad Akbar

International Conference on Information and Communication Technologies

Air borne sensed data is in the form of raster data. Aliasing is always present in a sampled image causing artifact error. To reduce possible aliasing effects, it is a good idea to blur an image slightly before applying a resampling method on it. This paper presents a technique for anti-aliasing remotely sensed images. The technique uses Gaussian low pass filter (GLPF) for generation of slight blur. Then resampling of raster data is performed with the help of bilinear interpolation. Algorithm is developed in MATLAB using some inbuilt functions.

Network Intrusion Detection: Monitoring, Simulation And Visualization, Mian Zhou

Electronic Theses and Dissertations

This dissertation presents our work on network intrusion detection and intrusion sim- ulation. The work in intrusion detection consists of two different network anomaly-based approaches. The work in intrusion simulation introduces a model using explicit traffic gen- eration for the packet level traffic simulation. The process of anomaly detection is to first build profiles for the normal network activity and then mark any events or activities that deviate from the normal profiles as suspicious. Based on the different schemes of creating the normal activity profiles, we introduce two approaches for intrusion detection. The first one is a frequency-based approach which …

Maintaining Stability With Distributed Generation In A Restructured Industry, Judith Cardell, Marija Ilic

Engineering: Faculty Publications

A set of reduced order, linearized, dynamic models for distributed generators is developed along with a framework for modeling the generators in a power distribution system. Analysis of this distributed system structure raises two issues. The first is that the simulations demonstrate, unexpectedly, that a small load disturbance is capable of causing frequency instability in the primary dynamics of the distributed generators. Eigenanalysis of the instability suggests that it is a system phenomenon. The second issue is that the system matrix is found to not have a block diagonal dominant structure raising questions over the possible implementation of decentralized control …

Multi-Level Modeling Of Software On Hardware In Concurrent Computation, Joann M. Paul, Arne Suppe, Henele I. Adams, Donald E. Thomas

Research Collection School Of Computing and Information Systems

The fundamental modeling differences between hardware and software modeling can be thought of as reasoning about connectedness vs. reasoning about interleaved (shared) access to resources. A natural design hierarchy for physical systems is component-based because of the existence of a consistent basis for interconnect between design levels. However, performance modeling and design of concurrent, programmable systems require new ways of thinking about what it means to abstract detail, add detail and partition a model of software executing on hardware. We motivate frequency interleaving (FI) as a common simulation foundation for these systems because it resolves flow and partitioning with software …

Connectionist Expert System With Adaptive Learning Capability, B. T. Low, Hochung Lui, Ah-Hwee Tan, Hoonheng Teh

Research Collection School Of Computing and Information Systems

A neural network expert system called adaptive connectionist expert system (ACES) which will learn adaptively from past experience is described. ACES is based on the neural logic network, which is capable of doing both pattern processing and logical inferencing. The authors discuss two strategies, pattern matching ACES and rule inferencing ACES. The pattern matching ACES makes use of past examples to construct its neural logic network and fine-tunes itself adaptively during its use by further examples supplied. The rule inferencing ACES conceptualizes new rules based on the frequencies of use on the rule-based neural logic network. A new rule could …