Physical Sciences and Mathematics Commons^™

Co2vec: Embeddings Of Co-Ordered Networks Based On Mutual Reinforcement, Meng-Fen Chiang, Ee-Peng Lim, Wang-Chien Lee, Philips Kokoh Prasetyo

Research Collection School Of Computing and Information Systems

We study the problem of representation learning for multiple types of entities in a co-ordered network where order relations exist among entities of the same type, and association relations exist across entities of different types. The key challenge in learning co-ordered network embedding is to preserve order relations among entities of the same type while leveraging on the general consistency in order relations between different entity types. In this paper, we propose an embedding model, CO2Vec, that addresses this challenge using mutually reinforced order dependencies. Specifically, CO2Vec explores in-direct order dependencies as supplementary evidence to enhance order representation learning across …

Establishing Topological Data Analysis: A Comparison Of Visualization Techniques, Tanmay J. Kotha

USF Tampa Graduate Theses and Dissertations

When visualizing data, we would like to convey both the data and the uncertainty associated with it. There are many incentives to do this, ranging from hurricane path projection to geographical surveys. Important decision making tasks rely upon humans perceiving a clear picture of the data and having confidence in their decisions. Topological Data Analysis has the potential to visualize the data as features or hierarchies in ways that are familiar to human intuition, and thus could help us convey the variation associated with uncertainty.

In this thesis, we evaluate four visualization techniques: color maps, isocontours, Reeb graphs, and persistence …

Color Face Image Recognition Based On Lbpt Method, Jihua Ye, Yahui Chen, Shimin Wang

Journal of System Simulation

Abstract: Aiming to the shortcomings of exiting algorithm to obtain better color face image information for color facial image recognition, the LBPT algorithm was proposed to realize the high efficiency recognition of color face image. LBPT algorithm reflected the texture features of gray image through adaptively obtaining neighborhood radius, ascertaining the relationship between neighborhood radius and neighborhood pixel number, setting threshold. The RGB color model was used to separate the color face image into the R,G,B three component diagrams. The LBPT algorithm was used to obtain the feature of the component diagrams. In order to realize further recognition, the method …

Towards Characterizing Adversarial Defects Of Deep Learning Software From The Lens Of Uncertainty, Xiyue Zhang, Xiaofei Xie, Lei Ma, Xiaoning Du, Qiang Hu, Yang Liu, Jianjun Zhao, Meng Sun

Research Collection School Of Computing and Information Systems

Over the past decade, deep learning (DL) has been successfully applied to many industrial domain-specific tasks. However, the current state-of-the-art DL software still suffers from quality issues, which raises great concern especially in the context of safety- and security-critical scenarios. Adversarial examples (AEs) represent a typical and important type of defects needed to be urgently addressed, on which a DL software makes incorrect decisions. Such defects occur through either intentional attack or physical-world noise perceived by input sensors, potentially hindering further industry deployment. The intrinsic uncertainty nature of deep learning decisions can be a fundamental reason for its incorrect behavior. …

Relationship Between Risk Identification, Risk Response, And Project Success, Marsha Marinich

Walden Dissertations and Doctoral Studies

AbstractProjects are used to implement the organization's strategic goals, but high failure rates reduce projects' effectiveness in successfully achieving goals. High failure rates reduce project managers’ effectiveness of projects in successfully achieving goals. Senior leaders and project managers are unable to deliver successful projects due to unmanaged risks. Grounded in expected utility theory, the purpose of this quantitative correlational study was to examine the relationship between risk identification, risk responses, and project success. A survey was created in SurveyMonkey® and distributed on LinkedIn. Survey responses were analyzed from 71 project managers with at least five years of experience in Washington, …

Uncertainty Learning In Subjective Logic And Pattern Discovery In Network Data, Adilijiang Alimu

Legacy Theses & Dissertations (2009 - 2024)

Uncertainty caused by unreliable or insufficient data and vulnerable machine learning models

Gcps Adaptive Scheduling Model Based On Cooperative Executor, Zhang Jing, Chen Yao, Sun Jun, Hongbo Fan

Journal of System Simulation

Abstract: Aiming at the problem that the uncertainty of grid cyber physical systems leads to chain failure, an adaptive GCPS dispatching model based on co-actuator is established. First, the constraint conditions of the system are analyzed. A model constraints of GCPS system is presented to describe the constraint conditions of the power system, and it is proved that it meets the consistency of the measure and representing methods. Second, the optimal value of approximation error is solved by PILOT, and the framework of CA-SADM is described. Finally, the performance index, output power accuracy and the influence of fault on the …

Method Of Power System Energy Storage Configuration Based On Flexibility Promotion, Weiqing Sun, Li Zhen, Yiming Tan, Fenglei Lü, Wenping Qiu, Hongzhong Li

Journal of System Simulation

Abstract: To solve the problem of renewable energy access and aiming at system’s response capability to short-term uncertainty, power system flexibility and its evaluation index are defined. A method of energy storage configuration based on flexibility evaluation is proposed. The uncertainty from power supply is analyzed. Aiming at the uncertainty of renewable energy, a source flexibility evaluation index is defined. The principle and method of energy storage configuration are presented from the aspect of siting and sizing. The energy storage configuration model is created and solved considering both the system flexibility requirements and energy storage costs based on the …

Transmission Expansion Planning Based On A Hybrid Genetic Algorithm Approachunder Uncertainty, Ercan Şenyi̇ği̇t, Selçuk Mutlu, Bi̇lal Babayi̇ği̇t

Turkish Journal of Electrical Engineering and Computer Sciences

Transmission expansion planning (TEP) is one of the key decisions in power systems. Its impact on the system?s operation is excessive and long-lived. The aim of TEP is to determine new transmission lines effectively for a current transmission grid to fulfill the model objectives. However, to obtain a solution, especially under uncertainty, is extremely difficult due to the nonlinear mixed-integer structure of the TEP problem. In this paper, first genetic algorithm (GA) approaches for TEP are reviewed in the literature and then a new hybrid GA with linear modeling is proposed. The proposed GA method has a flexible structure and …

Adaptive Heuristics That (Could) Fit: Information Search And Communication Patterns In An Online Forum Of Investors Under Market Uncertainty, Niccolo Casnici, Marco Castellani, Flaminio Squazzoni, Manuela Testa, Pierpaolo Dondio

Articles

This article examines information-search heuristics and communication patterns in an online forum of investors during a period of market uncertainty. Global connections, real-time communication, and technological sophistication have created an unpredictable market environment. As such, investors try to deal with semantic, strategic, and operational uncertainty by following heuristics that reduce information redundancy. In this study, we have tried to find traces of cognitive communication heuristics in a large-scale data set including 8 years of online posts (2004–2012) for a forum of Italian investors. We identified various market volatility conditions on a daily basis to understand the influence of market uncertainty …

Proactive And Reactive Resource/Task Allocation For Agent Teams In Uncertain Environments, Pritee Agrawal

Dissertations and Theses Collection (Open Access)

Synergistic interactions between task/resource allocation and multi-agent coordinated planning/assignment exist in many problem domains such as trans- portation and logistics, disaster rescue, security patrolling, sensor networks, power distribution networks, etc. These domains often feature dynamic environments where allocations of tasks/resources may have complex dependencies and agents may leave the team due to unforeseen conditions (e.g., emergency, accident or violation, damage to agent, reconfiguration of environment).

Parameter-Free Aggregation Of Value Functions From Multiple Experts And Uncertainty Assessment In Multi-Criteria Evaluation, Benjamin Rohrbach, Robert Weibel, Patrick Laube

Journal of Spatial Information Science

This paper makes a threefold contribution to spatial multi-criteria evaluation (MCE): firstly by presenting a new method concerning value functions, secondly by comparing different approaches to assess the uncertainty of a MCE outcome, and thirdly by presenting a case-study on land-use change. Even though MCE is a well-known methodology in GIScience, there is a lack of practicable approaches to incorporate the potentially diverse views of multiple experts in defining and standardizing the values used to implement input criteria. We propose a new method that allows generating and aggregating non-monotonic value functions, integrating the views of multiple experts. The new approach …

Uncertainty Estimation Of Deep Neural Networks, Chao Chen

Theses and Dissertations

Normal neural networks trained with gradient descent and back-propagation have received great success in various applications. On one hand, point estimation of the network weights is prone to over-fitting problems and lacks important uncertainty information associated with the estimation. On the other hand, exact Bayesian neural network methods are intractable and non-applicable for real-world applications. To date, approximate methods have been actively under development for Bayesian neural networks, including but not limited to: stochastic variational methods, Monte Carlo dropouts, and expectation propagation. Though these methods are applicable for current large networks, there are limits to these approaches with either underestimation …

Decision Making For Dynamic Systems Under Uncertainty: Predictions And Parameter Recomputations, Leobardo Valera

Open Access Theses & Dissertations

In this Thesis, we are interested in making decision over a model of a dynamic system. We want to know, on one hand, how the corresponding dynamic phenomenon unfolds under different input parameters (simulations). These simulations might help researchers to design devices with a better performance than the actual ones. On the other hand, we are also interested in predicting the behavior of the dynamic system based on knowledge of the phenomenon in order to prevent undesired outcomes. Finally, this Thesis is concerned with the identification of parameters of dynamic systems that ensure a specific performance or behavior.

Understanding the …

How To Deal With Uncertainties In Computing: From Probabilistic And Interval Uncertainty To Combination Of Different Approaches, With Applications To Engineering And Bioinformatics, Vladik Kreinovich

Departmental Technical Reports (CS)

Most data processing techniques traditionally used in scientific and engineering practice are statistical. These techniques are based on the assumption that we know the probability distributions of measurement errors etc.

In practice, often, we do not know the distributions, we only know the bound D on the measurement accuracy -- hence, after the get the measurement result X, the only information that we have about the actual (unknown) value x of the measured quantity is that $x$ belongs to the interval [X − D, X + D]. Techniques for data processing under such interval uncertainty are called interval computations; these …

Advanced Probabilistic Power Flow Methodology For Power Systems With Renewable Resources, Dinh Duong Le, Nhi Thi Ai Nguyen, Van Duong Ngo, Alberto Berizzi

Turkish Journal of Electrical Engineering and Computer Sciences

Renewable~resources have added additional uncertainty to power grids. Deterministic power flow does not provide sufficient information for power system calculation and analysis, since all sources of uncertainty are not taken into account. To handle uncertainties PPF has been introduced and used as an efficient tool. In this paper, we present a cumulant-based PPF approach that can account for various sources of uncertainty in power systems with renewable resources such as wind and photovoltaic energy. We also propose the use of a new methodology to estimate probability distribution for wind power output based on measured data. The proposed approach is carried …

Periodic Control For The Cart Pendulum System With Structured Uncertainty, Arindam Chakraborty, Jayati Dey

Turkish Journal of Electrical Engineering and Computer Sciences

The robust stabilization of the cart pendulum system was studied under structured uncertainty with a continuous-time periodic controller. The cart pendulum system was considered here as the test set-up as it is a well-known example of an unstable nonminimum phase system. The uncertainty in the system rose due to measurement error or dry friction in it. In this paper, the robust stability of the periodic controller in the presence of uncertainty was examined. The gain margin and delay margin endow with the periodic controller were superior to those obtained in the case of linear time invariant (LTI) control even in …

Partitioning Uncertain Workloads, Freddy Chua, Bernardo A. Huberman

Research Collection School Of Computing and Information Systems

We present a method for determining the ratio of the tasks when breaking any complex workload in such a way that once the outputs from all tasks are joined, their full completion takes less time and exhibit smaller variance than when running on the undivided workload. To do that, we have to infer the capabilities of the processing unit executing the divided workloads or tasks. We propose a Bayesian Inference algorithm to infer the amount of time each task takes in a way that does not require prior knowledge on the processing unit capability. We demonstrate the effectiveness of this …

Combining Interval And Probabilistic Uncertainty In Engineering Applications, Andrew Martin Pownuk

Open Access Theses & Dissertations

In many practical application, we process measurement results and expert estimates. Measurements and expert estimates are never absolutely accurate, their result are slightly different from the actual (unknown) values of the corresponding quantities. It is therefore desirable to analyze how this measurement and estimation inaccuracy affects the results of data processing. There exist numerous methods for estimating the accuracy of the results of data processing under different models of measurement and estimation inaccuracies: probabilistic, interval, and fuzzy. To be useful in engineering applications, these methods should provide accurate estimate for the resulting uncertainty, should not take too much computation time, …

Experience Me! The Impact Of Content Sampling Strategies On The Marketing Of Digital Entertainment Goods, Ai Phuong Hoang, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

Product sampling allows consumers to try out a small portion of a product for free. Uncertainty associated with consumption of information goods makes sampling useful for digital entertainment providers. Firms offer some programming for free to attract consumers to purchase a series of programs. We explore the effectiveness of content sampling for information goods using a dataset containing more than 17 million free previews and purchase observations on households from a digital entertainment firm that offers video-on-demand (VoD). Based on theories related to product sampling and information goods, we analyze the relationship between free previews and VoD purchases for series …

Towards A Science Of Security Games, Thanh Hong Nguyen, Debarun Kar, Matthew Brown, Arunesh Sinha, Albert Xin Jiang, Milind Tambe

Research Collection School Of Computing and Information Systems

Security is a critical concern around the world. In many domains from counter-terrorism to sustainability, limited security resources prevent full security coverage at all times; instead, these limited resources must be scheduled, while simultaneously taking into account different target priorities, the responses of the adversaries to the security posture and potential uncertainty over adversary types.Computational game theory can help design such security schedules. Indeed, casting the problem as a Bayesian Stackelberg game, we have developed new algorithms that are now deployed over multiple years in multiple applications for security scheduling. These applications are leading to real-world use-inspired research in the …

An Interval-Based Contingency Selection Approach Considering Uncertainty, Chao Xu, Wei Gu, Lizi Luo, Jianguo Yao, Shengchun Yang, Ke Wang, Dan Zeng, Miao Fan

Turkish Journal of Electrical Engineering and Computer Sciences

Static security assessment is affected by uncertainties of load flow distributions introduced by renewable sources. A fast contingency selection approach based on interval theory is proposed in this paper. Firstly, an interval line active flow calculation algorithm is developed to reduce conservation in application of interval mathematics in line flow calculation. Then a novel interval comparison method based on Bayesian probability theory is applied in interval index comparison to give the relative severity information of contingencies. Finally, an approximately consistent ranking method is utilized in contingency ranking to rank screened contingencies. Numerical studies on several IEEE standard test systems and …

Robust Distributed Scheduling Via Time Period Aggregation, Shih-Fen Cheng, John Tajan, Hoong Chuin Lau

Shih-Fen Cheng

In this paper, we evaluate whether the robustness of a market mechanism that allocates complementary resources could be improved through the aggregation of time periods in which resources are consumed. In particular, we study a multi-round combinatorial auction that is built on a general equilibrium framework. We adopt the general equilibrium framework and the particular combinatorial auction design from the literature, and we investigate the benefits and the limitation of time-period aggregation when demand-side uncertainties are introduced. By using simulation experiments on a real-life resource allocation problem from a container port, we show that, under stochastic conditions, the performance variation …

Robust Distributed Scheduling Via Time Period Aggregation, Shih-Fen Cheng, John Tajan, Hoong Chuin Lau

Shih-Fen Cheng

In this paper, we evaluate whether the robustness of a market mechanism that allocates complementary resources could be improved through the aggregation of time periods in which resources are consumed. In particular, we study a multi-round combinatorial auction that is built on a general equilibrium framework. We adopt the general equilibrium framework and the particular combinatorial auction design from the literature, and we investigate the benefits and the limitation of time-period aggregation when demand-side uncertainties are introduced. By using simulation experiments on a real-life resource allocation problem from a container port, we show that, under stochastic conditions, the performance variation …

Robust Distributed Scheduling Via Time Period Aggregation, Shih-Fen Cheng, John Tajan, Hoong Chuin Lau

Shih-Fen CHENG

In this paper, we evaluate whether the robustness of a market mechanism that allocates complementary resources could be improved through the aggregation of time periods in which resources are consumed. In particular, we study a multi-round combinatorial auction that is built on a general equilibrium framework. We adopt the general equilibrium framework and the particular combinatorial auction design from the literature, and we investigate the benefits and the limitation of time-period aggregation when demand-side uncertainties are introduced. By using simulation experiments on a real-life resource allocation problem from a container port, we show that, under stochastic conditions, the performance variation …

Demand Response In The Day-Ahead Operation Of An Isolated Microgrid In The Presence Of Uncertainty Of Wind Power, Javad Olamaei, Saleh Ashouri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper explores the utilization of demand response in the day-ahead operation of an isolated microgrid in the presence of wind units. The operation of the network with high penetration wind units (i.e. uncertainty of wind units) is modeled as a unit commitment problem. In addition, electrical power storage is modeled in a daily power curve to decrease the effect of uncertainty in the wind units. Due to avoiding large-scale complexities and the deeper study effect of demand-side management on operations, the considered network is regarded as an isolated microgrid. The demand-side management is studied as demand shifting. The simulation …

Optimization Of Grid Connected Micro-Grid Consisting Of Pv/Fc/Uc With Considered Frequency Control, Hamid Hasanzadehfard, Masoud Moghaddas-Tafreshi, Sayed Mehdi Hakimi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, ultracapacitors are used as short-term storages for the frequency control of grid-connected microgrid that consists of photovoltaic panels, fuel cells, and the battery packs as long-term storages. Fuel cells and battery packs have delays in load tracking; therefore, ultracapacitors are used to compensate for the sudden power fluctuations in the microgrid that occur due to the output power uncertainty of the PV arrays and the loads required in the microgrid, as well as the sudden interruption of the main grid. The microgrid consists of interruptible and uninterruptible loads. When the total produced power in the microgrid, in …

Fuzzy Mathematical Models Of Type-1 And Type-2 For Computing The Parameters And Its Applications, R.W. W. Hndoosh

R. W. Hndoosh

This work provides mathematical formulas and algorithm in order to calculate the derivatives that being necessary to perform Steepest Descent models to make T1 and T2 FLSs much more accessible to FLS modelers. It provides derivative computations that are applied on different kind of MFs, and some computations which are then clarified for specific MFs. We have learned how to model T1 FLSs when a set of training data is available and provided an application to derive the Steepest Descent models that depend on trigonometric function (SDTFM). This work, also focused on an interval type-2 non-singleton type-2 FLS (IT2 NS-T2 …

Visual Analysis Of Uncertainty In Trajectories, Lu Lu, Nan Cao, Siyuan Liu, Lionel Ni, Xiaoru Yuan, Huamin Qu

Research Collection School Of Computing and Information Systems

Mining trajectory datasets has many important applications. Real trajectory data often involve uncertainty due to inadequate sampling rates and measurement errors. For some trajectories, their precise positions cannot be recovered and the exact routes that vehicles traveled cannot be accurately reconstructed. In this paper, we investigate the uncertainty problem in trajectory data and present a visual analytics system to reveal, analyze, and solve the uncertainties associated with trajectory samples. We first propose two novel visual encoding schemes called the road map analyzer and the uncertainty lens for discovering road map errors and visually analyzing the uncertainty in trajectory data respectively. …

Optimizing Resolution And Uncertainty In Bathymetric Sonar Systems, Val E. Schmidt, Thomas C. Weber, Xavier Lurton

Center for Coastal and Ocean Mapping

Bathymetric sonar systems (whether multibeam or phase-differencing sidescan) contain an inherent trade-off between resolution and uncertainty. Systems are traditionally designed with a fixed spatial resolution, and the parameter settings are optimized to minimize the uncertainty in the soundings within that constraint. By fixing the spatial resolution of the system, current generation sonars operate sub-optimally when the SNR is high, producing soundings with lower resolution than is supportable by the data, and inefficiently when the SNR is low, producing high-uncertainty soundings of little value. Here we propose fixing the sounding measurement uncertainty instead, and optimizing the resolution of the system within …