Impulsive differential equations by using the Euler method

The theory of impulsive differential equations is emerging as an important area of investigation since such equations appear to represent a natural framework for mathematical modeling of several real phenomena. There have been intensive studies on the qualitative behavior of solutions of the impulsive differential equations. However, many impulsive differential equations cannot be solved analytically or their solving is complicated. In this paper, we represent the algorithm which follows the theory of impulsive differential equations to solve the impulsive differential equations by using the Euler methods. It is clearly shown the impulsive operators k I that acts at the moments k t influence the error. Finally, the better convergence result of the numerical solution is given by solving the numerical examples

Impulsive differential equations by using the Euler method

The theory of impulsive differential equations is emerging as an important area of investigation since such equations appear to represent a natural framework for mathematical modeling of several real phenomena. There have been intensive studies on the qualitative behavior of solutions of the impulsive differential equations. However, many impulsive differential equations cannot be solved analytically or their solving is complicated. In this paper, we represent the algorithm which follows the theory of impulsive differential equations to solve the impulsive differential equations by using the Euler methods. It is clearly shown the impulsive operators k I that acts at the moments k t influence the error. Finally, the better convergence result of the numerical solution is given by solving the numerical examples

Computer Entertainment Technologies for the Visually Impaired: An Overview

Over the last years, works related to accessible technologies have increased both in number and in quality. This work presents a series of articles which explore different trends in the field of accessible video games for the blind or visually impaired. Reviewed articles are distributed in four categories covering the following subjects: (1) video game design and architecture, (2) video game adaptations, (3) accessible games as learning tools or treatments and (4) navigation and interaction in virtual environments. Current trends in accessible game design are also analysed, and data is presented regarding keyword use and thematic evolution over time. As a conclusion, a relative stagnation in the field of human-computer interaction for the blind is detected. However, as the video game industry is becoming increasingly interested in accessibility, new research opportunities are starting to appear

Motion Compatibility for Indoor Localization

Indoor localization -- a device's ability to determine its location within an extended indoor environment -- is a fundamental enabling capability for mobile context-aware applications. Many proposed applications assume localization information from GPS, or from WiFi access points. However, GPS fails indoors and in urban canyons, and current WiFi-based methods require an expensive, and manually intensive, mapping, calibration, and configuration process performed by skilled technicians to bring the system online for end users. We describe a method that estimates indoor location with respect to a prior map consisting of a set of 2D floorplans linked through horizontal and vertical adjacencies. Our main contribution is the notion of "path compatibility," in which the sequential output of a classifier of inertial data producing low-level motion estimates (standing still, walking straight, going upstairs, turning left etc.) is examined for agreement with the prior map. Path compatibility is encoded in an HMM-based matching model, from which the method recovers the user s location trajectory from the low-level motion estimates. To recognize user motions, we present a motion labeling algorithm, extracting fine-grained user motions from sensor data of handheld mobile devices. We propose "feature templates," which allows the motion classifier to learn the optimal window size for a specific combination of a motion and a sensor feature function. We show that, using only proprioceptive data of the quality typically available on a modern smartphone, our motion labeling algorithm classifies user motions with 94.5% accuracy, and our trajectory matching algorithm can recover the user's location to within 5 meters on average after one minute of movements from an unknown starting location. Prior information, such as a known starting floor, further decreases the time required to obtain precise location estimate

Enhancing travel experience with the combination of information visualization, situation awareness, and distributed cognition

With the new forms of travel introduced by new technologies of transportation and communication, a satisfied travel experience could be affected by various factors before and during a trip. Especially for road trips, traveling by car provides freedom on time control while leading to more possibilities of rescheduling initial plans made under time constraints. When overwhelmed with the need for changed travel context to avoid unexpected events that will require a serious change of initial plans, travelers need to find and access helpful contextual information quickly. This is a context-related decision making process that requires amplifying human situation awareness and supporting distributed cognition, since travel information offers multiple choices. To solve this problem, I applied information visualization as the main design solution. When comparing it with a traditional representation of lists, information visualization displays the advantages of visual representation of abstract data to clarify and depict the information and amplify cognition while improving travel experience intuitively in the domain of user experience design. Therefore in this thesis I will address the approach of implementing recontextualized situation awareness, distributed cognition, and information visualization in a travel-aid system. By using both theoretical and practical design perspectives, I will discuss how to enhance travel experience with represented contextual information that users desire or expect before and during a road trip. I will also explore the new values of this design with strategic business support. Additionally, after conducting research and analysis on existing interaction design parts, I selected a smartphone app to serve as a proper platform with connected multifunctions. Briefly, I begin the thesis with a review of previous theories and aspects of travel planning, information visualization as it relates to travel, situation awareness, and distributed cognition in the design context and related smartphone apps. Then I discuss the process of identifying the specific issues to be solved or improved with a preliminary research of empirical study, followed by an interview, online survey, insights synthesis, and business model design. After a visual-system design was developed, heuristic evaluation was employed to assess the outcome. Lastly, a new round of refined design results is introduced based on outcomes of the evaluation

LandMarkAR: An application to study virtual route instructions and the design of 3D landmarks for indoor pedestrian navigation with a mixed reality head-mounted display

Mixed Reality (MR) interfaces on head-mounted displays (HMDs) have the potential to replace screen-based interfaces as the primary interface to the digital world. They potentially offer a more immersive and less distracting experience compared to mobile phones, allowing users to stay focused on their environment and main goals while accessing digital information. Due to their ability to gracefully embed virtual information in the environment, MR HMDs could potentially alleviate some of the issues plaguing users of mobile pedestrian navigation systems, such as distraction, diminished route recall, and reduced spatial knowledge acquisition. However, the complexity of MR technology presents significant challenges, particularly for researchers with limited programming knowledge. This thesis presents “LandMarkAR” to address those challenges. “LandMarkAR” is a HoloLens application that allows researchers to create augmented territories to study human navigation with MR interfaces, even if they have little programming knowledge. “LandMarkAR” was designed using different methods from human-centered design (HCD), such as design thinking and think-aloud testing, and was developed with Unity and the Mixed Reality Toolkit (MRTK). With “LandMarkAR”, researchers can place and manipulate 3D objects as holograms in real-time, facilitating indoor navigation experiments using 3D objects that serve as turn-by-turn instructions, highlights of physical landmarks, or other information researchers may come up with. Researchers with varying technical expertise will be able to use “LandMarkAR” for MR navigation studies. They can opt to utilize the easy-to-use User Interface (UI) on the HoloLens or add custom functionality to the application directly in Unity. “LandMarkAR” empowers researchers to explore the full potential of MR interfaces in human navigation and create meaningful insights for their studies

Distributed Space Traffic Management Solutions with Emerging New Space Industry

Day-to-day services, from weather forecast to logistics, rely on space-based infrastructures whose integrity is crucial to stakeholders and end-users worldwide. Current trends point towards congestion of the near-Earth space environment increasing at a rate greater than existing systems support, and thus demand novel cost-efficient approaches to traffic detection, characterization, tracking, and management to ensure space remains a safe, integral part of societies and economies worldwide. Whereas machine-learning (ML) and artificial intelligence (AI) have been extensively proposed to address congestion and alleviate big-data problems of the future, little has been done so far to tackle the need for transnational coordination and conflict-resolution in the context of space traffic management (STM). In STM, there is an ever-growing need for distributing information and coordinating actions (e.g., avoidance manoeuvres) to reduce the operational costs borne by individual entities and to decrease the latencies of actionable responses taken upon the detection of hazardous conditions by one-to-two orders of magnitude. However, these needs are not exclusive to STM, as evidenced by the widespread adoption of solutions to distributing, coordinating, and automating actions in other industries such as air traffic management (ATM), where a short-range airborne collision avoidance system (ACAS) automatically coordinates evasive manoeuvres whenever a conjunction is detected. Within this context, this paper aims at establishing a roadmap of promising technologies (e.g., blockchain), protocols and processes that could be adapted from different domains (railway, automotive, aerial, and maritime) to build an integrated traffic coordination and communication architecture to simplify and harmonise stakeholders’ satellite operations. This paper is organised into seven sections. First, Section 1 introduces the problem of STM, highlighting its complexity. Following this introduction, Section 2 discusses needs and requirements of various stakeholders such as commercial operators, space situational awareness (SSA) service providers, launch-service providers, satellite and constellation owners, governmental agencies, regulators, and insurance companies. Then, Section 3 addresses existing gaps and challenges in STM, focusing on globally coordinated approaches. Next, Section 4 reviews technologies for distributed, secure, and persistent communications, and proposed solutions to address some of these challenges from non-space sectors. Thereafter, Section 5 briefly covers the history of STM proposals and presents the state-of-the-art solution being proposed for modern STM. Following this review, Section 6 devises a step-by-step plan for exploiting and deploying some of the identified technologies within a five-to-ten-year timeline to close several existing gaps. Finally, Section 7 concludes the paper