MOBILE CLOUD COMPUTING APPLIED TO HEALTHCARE APPROACH

OpenAIRE

Omar AlSheikSalem

2016-01-01

In the past few years it was clear that mobile cloud computing was established via integrating both mobile computing and cloud computing to be add in both storage space and processing speed. Integrating healthcare applications and services is one of the vast data approaches that can be adapted to mobile cloud computing. This work proposes a framework of a global healthcare computing based combining both mobile computing and cloud computing. This approach leads to integrate all of ...

Mobile healthcare information management utilizing Cloud Computing and Android OS.

Science.gov (United States)

Doukas, Charalampos; Pliakas, Thomas; Maglogiannis, Ilias

2010-01-01

Cloud Computing provides functionality for managing information data in a distributed, ubiquitous and pervasive manner supporting several platforms, systems and applications. This work presents the implementation of a mobile system that enables electronic healthcare data storage, update and retrieval using Cloud Computing. The mobile application is developed using Google's Android operating system and provides management of patient health records and medical images (supporting DICOM format and JPEG2000 coding). The developed system has been evaluated using the Amazon's S3 cloud service. This article summarizes the implementation details and presents initial results of the system in practice.

COMPSs-Mobile: parallel programming for mobile-cloud computing

OpenAIRE

Lordan Gomis, Francesc-Josep; Badia Sala, Rosa Maria

2016-01-01

The advent of Cloud and the popularization of mobile devices have led us to a shift in computing access. Computing users will have an interaction display while the real computation will be performed remotely, in the Cloud. COMPSs-Mobile is a framework that aims to ease the development of energy-efficient and high-performing applications for this environment. The framework provides an infrastructure-unaware programming model that allows developers to code regular Android applications that, ...

Mobile human-computer interaction perspective on mobile learning

CSIR Research Space (South Africa)

Botha, Adèle

2010-10-01

Full Text Available Applying a Mobile Human Computer Interaction (MHCI) view to the domain of education using Mobile Learning (Mlearning), the research outlines its understanding of the influences and effects of different interactions on the use of mobile technology...

Mobile computing initiatives within pharmacy education.

Science.gov (United States)

Cain, Jeff; Bird, Eleanora R; Jones, Mikael

2008-08-15

To identify mobile computing initiatives within pharmacy education, including how devices are obtained, supported, and utilized within the curriculum. An 18-item questionnaire was developed and delivered to academic affairs deans (or closest equivalent) of 98 colleges and schools of pharmacy. Fifty-four colleges and schools completed the questionnaire for a 55% completion rate. Thirteen of those schools have implemented mobile computing requirements for students. Twenty schools reported they were likely to formally consider implementing a mobile computing initiative within 5 years. Numerous models of mobile computing initiatives exist in terms of device obtainment, technical support, infrastructure, and utilization within the curriculum. Responders identified flexibility in teaching and learning as the most positive aspect of the initiatives and computer-aided distraction as the most negative, Numerous factors should be taken into consideration when deciding if and how a mobile computing requirement should be implemented.

HCI in Mobile and Ubiquitous Computing

OpenAIRE

椎尾, 一郎; 安村, 通晃; 福本, 雅明; 伊賀, 聡一郎; 増井, 俊之

2003-01-01

This paper provides some perspectives to human computer interaction in mobile and ubiquitous computing. The review covers overview of ubiquitous computing, mobile computing and wearable computing. It also summarizes HCI topics on these field, including real-world oriented interface, multi-modal interface, context awareness and in-visible computers. Finally we discuss killer applications for coming ubiquitous computing era.

A Prototype User Interface for a Mobile Electronic Clinical Note Data Entry System

OpenAIRE

Zafar, Atif; Lehto, Mark; Kim, Jongseo

2005-01-01

Recent advances in mobile computing technologies have made electronic medical records (EMRs) on handheld devices an attractive possibility. However, data entry paradigms popular on desktop machines do not translate well to mobile devices1,2. Based on a review of the literature on mobile device usability1–4, we built a prototype user interface for mobile EMRs and held focus groups with clinician users whose feedback provided useful insight about design choices, functionality and...

Calculation and analysis of the mobility and diffusion coefficient of thermal electrons in methane/air premixed flames

KAUST Repository

Bisetti, Fabrizio

2012-12-01

Simulations of ion and electron transport in flames routinely adopt plasma fluid models, which require transport coefficients to compute the mass flux of charged species. In this work, the mobility and diffusion coefficient of thermal electrons in atmospheric premixed methane/air flames are calculated and analyzed. The electron mobility is highest in the unburnt region, decreasing more than threefold across the flame due to mixture composition effects related to the presence of water vapor. Mobility is found to be largely independent of equivalence ratio and approximately equal to 0.4m 2V -1s -1 in the reaction zone and burnt region. The methodology and results presented enable accurate and computationally inexpensive calculations of transport properties of thermal electrons for use in numerical simulations of charged species transport in flames. © 2012 The Combustion Institute.

Mobile computing deployment and management real world skills for Comptia Mobility+ certification and beyond

CERN Document Server

Bartz, Robert J

2015-01-01

Mobile computing skills are becoming standard in the IT industry Mobile Computing Deployment and Management: Real World Skills for CompTIA Mobility+ Certification and Beyond is the ultimate reference for mobile computing. Certified Wireless Network Expert Robert J. Bartz guides IT and networking professionals through the fundamental and advanced concepts of mobile computing, providing the information and instruction necessary to get up to speed on current technology and best practices. The book maps to the CompTIA Mobility+ (MB0-001) exam, making it an ideal resource for those s

Resource Management in Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Andrei IONESCU

2015-01-01

Full Text Available Mobile cloud computing is a major research topic in Information Technology & Communications. It integrates cloud computing, mobile computing and wireless networks. While mainly built on cloud computing, it has to operate using more heterogeneous resources with implications on how these resources are managed and used. Managing the resources of a mobile cloud is not a trivial task, involving vastly different architectures. The process is outside the scope of human users. Using the resources by the applications at both platform and software tiers come with its own challenges. This paper presents different approaches in use for managing cloud resources at infrastructure and platform levels.

Mobile Agents in Networking and Distributed Computing

CERN Document Server

Cao, Jiannong

2012-01-01

The book focuses on mobile agents, which are computer programs that can autonomously migrate between network sites. This text introduces the concepts and principles of mobile agents, provides an overview of mobile agent technology, and focuses on applications in networking and distributed computing.

Computational Search for Two-Dimensional MX2 Semiconductors with Possible High Electron Mobility at Room Temperature

Directory of Open Access Journals (Sweden)

Zhishuo Huang

2016-08-01

Full Text Available Neither of the two typical two-dimensional materials, graphene and single layer MoS 2 , are good enough for developing semiconductor logical devices. We calculated the electron mobility of 14 two-dimensional semiconductors with composition of MX 2 , where M (=Mo, W, Sn, Hf, Zr and Pt are transition metals, and Xs are S, Se and Te. We approximated the electron phonon scattering matrix by deformation potentials, within which long wave longitudinal acoustical and optical phonon scatterings were included. Piezoelectric scattering in the compounds without inversion symmetry is also taken into account. We found that out of the 14 compounds, WS 2 , PtS 2 and PtSe 2 are promising for logical devices regarding the possible high electron mobility and finite band gap. Especially, the phonon limited electron mobility in PtSe 2 reaches about 4000 cm 2 ·V - 1 ·s - 1 at room temperature, which is the highest among the compounds with an indirect bandgap of about 1.25 eV under the local density approximation. Our results can be the first guide for experiments to synthesize better two-dimensional materials for future semiconductor devices.

The state of ergonomics for mobile computing technology.

Science.gov (United States)

Dennerlein, Jack T

2015-01-01

Because mobile computing technologies, such as notebook computers, smart mobile phones, and tablet computers afford users many different configurations through their intended mobility, there is concern about their effects on musculoskeletal pain and a need for usage recommendations. Therefore the main goal of this paper to determine which best practices surrounding the use of mobile computing devices can be gleaned from current field and laboratory studies of mobile computing devices. An expert review was completed. Field studies have documented various user configurations, which often include non-neutral postures, that users adopt when using mobile technology, along with some evidence suggesting that longer duration of use is associated with more discomfort. It is therefore prudent for users to take advantage of their mobility and not get stuck in any given posture for too long. The use of accessories such as appropriate cases or riser stands, as well as external keyboards and pointing devices, can also improve postures and comfort. Overall, the state of ergonomics for mobile technology is a work in progress and there are more research questions to be addressed.

Distributed computing by oblivious mobile robots

CERN Document Server

Flocchini, Paola; Santoro, Nicola

2012-01-01

The study of what can be computed by a team of autonomous mobile robots, originally started in robotics and AI, has become increasingly popular in theoretical computer science (especially in distributed computing), where it is now an integral part of the investigations on computability by mobile entities. The robots are identical computational entities located and able to move in a spatial universe; they operate without explicit communication and are usually unable to remember the past; they are extremely simple, with limited resources, and individually quite weak. However, collectively the ro

Mobile Computing: The Emerging Technology, Sensing, Challenges and Applications

International Nuclear Information System (INIS)

Bezboruah, T.

2010-12-01

The mobile computing is a computing system in which a computer and all necessary accessories like files and software are taken out to the field. It is a system of computing through which it is being able to use a computing device even when someone being mobile and therefore changing location. The portability is one of the important aspects of mobile computing. The mobile phones are being used to gather scientific data from remote and isolated places that could not be possible to retrieve by other means. The scientists are initiating to use mobile devices and web-based applications to systematically explore interesting scientific aspects of their surroundings, ranging from climate change, environmental pollution to earthquake monitoring. This mobile revolution enables new ideas and innovations to spread out more quickly and efficiently. Here we will discuss in brief about the mobile computing technology, its sensing, challenges and the applications. (author)

Using satellite communications for a mobile computer network

Science.gov (United States)

Wyman, Douglas J.

1993-01-01

The topics discussed include the following: patrol car automation, mobile computer network, network requirements, network design overview, MCN mobile network software, MCN hub operation, mobile satellite software, hub satellite software, the benefits of patrol car automation, the benefits of satellite mobile computing, and national law enforcement satellite.

Towards Scalable Graph Computation on Mobile Devices.

Science.gov (United States)

Chen, Yiqi; Lin, Zhiyuan; Pienta, Robert; Kahng, Minsuk; Chau, Duen Horng

2014-10-01

Mobile devices have become increasingly central to our everyday activities, due to their portability, multi-touch capabilities, and ever-improving computational power. Such attractive features have spurred research interest in leveraging mobile devices for computation. We explore a novel approach that aims to use a single mobile device to perform scalable graph computation on large graphs that do not fit in the device's limited main memory, opening up the possibility of performing on-device analysis of large datasets, without relying on the cloud. Based on the familiar memory mapping capability provided by today's mobile operating systems, our approach to scale up computation is powerful and intentionally kept simple to maximize its applicability across the iOS and Android platforms. Our experiments demonstrate that an iPad mini can perform fast computation on large real graphs with as many as 272 million edges (Google+ social graph), at a speed that is only a few times slower than a 13″ Macbook Pro. Through creating a real world iOS app with this technique, we demonstrate the strong potential application for scalable graph computation on a single mobile device using our approach.

Towards Scalable Graph Computation on Mobile Devices

Science.gov (United States)

Chen, Yiqi; Lin, Zhiyuan; Pienta, Robert; Kahng, Minsuk; Chau, Duen Horng

2015-01-01

Mobile devices have become increasingly central to our everyday activities, due to their portability, multi-touch capabilities, and ever-improving computational power. Such attractive features have spurred research interest in leveraging mobile devices for computation. We explore a novel approach that aims to use a single mobile device to perform scalable graph computation on large graphs that do not fit in the device's limited main memory, opening up the possibility of performing on-device analysis of large datasets, without relying on the cloud. Based on the familiar memory mapping capability provided by today's mobile operating systems, our approach to scale up computation is powerful and intentionally kept simple to maximize its applicability across the iOS and Android platforms. Our experiments demonstrate that an iPad mini can perform fast computation on large real graphs with as many as 272 million edges (Google+ social graph), at a speed that is only a few times slower than a 13″ Macbook Pro. Through creating a real world iOS app with this technique, we demonstrate the strong potential application for scalable graph computation on a single mobile device using our approach. PMID:25859564

Electron mobility in monoclinic β-Ga2O3—Effect of plasmon-phonon coupling, anisotropy, and confinement

Science.gov (United States)

Ghosh, Krishnendu; Singisetti, Uttam

2017-11-01

This work reports an investigation of electron transport in monoclinic \\beta-Ga2O3 based on a combination of density functional perturbation theory based lattice dynamical computations, coupling calculation of lattice modes with collective plasmon oscillations and Boltzmann theory based transport calculations. The strong entanglement of the plasmon with the different longitudinal optical (LO) modes make the role LO-plasmon coupling crucial for transport. The electron density dependence of the electron mobility in \\beta-Ga2O3 is studied in bulk material form and also in the form of two-dimensional electron gas. Under high electron density a bulk mobility of 182 cm2/ V.s is predicted while in 2DEG form the corresponding mobility is about 418 cm2/V.s when remote impurities are present at the interface and improves further as the remote impurity center moves away from the interface. The trend of the electron mobility shows promise for realizing high electron mobility in dopant isolated electron channels. The experimentally observed small anisotropy in mobility is traced through a transient Monte Carlo simulation. It is found that the anisotropy of the IR active phonon modes is responsible for giving rise to the anisotropy in low-field electron mobility.

76 FR 31983 - In the Matter of Certain Electronic Devices, Including Mobile Phones, Portable Music Players, and...

Science.gov (United States)

2011-06-02

... Devices, Including Mobile Phones, Portable Music Players, and Computers; Notice of Commission... States after importation of certain electronic devices, including mobile phones, portable music players... rendered asserted claim 5 invalid. The ALJ concluded that an industry exists within the United States that...

76 FR 40930 - In the Matter of Certain Electronic Devices, Including Mobile Phones, Portable Music Players, and...

Science.gov (United States)

2011-07-12

... Devices, Including Mobile Phones, Portable Music Players, and Computers; Notice of Commission....S.C. 1337) in the importation into the United States, the sale for importation, and the sale within the United States after importation of certain electronic devices, including mobile phones, portable...

Calculation and analysis of the mobility and diffusion coefficient of thermal electrons in methane/air premixed flames

KAUST Repository

Bisetti, Fabrizio; El Morsli, Mbark

2012-01-01

Simulations of ion and electron transport in flames routinely adopt plasma fluid models, which require transport coefficients to compute the mass flux of charged species. In this work, the mobility and diffusion coefficient of thermal electrons

Organic High Electron Mobility Transistors Realized by 2D Electron Gas.

Science.gov (United States)

Zhang, Panlong; Wang, Haibo; Yan, Donghang

2017-09-01

A key breakthrough in inorganic modern electronics is the energy-band engineering that plays important role to improve device performance or develop novel functional devices. A typical application is high electron mobility transistors (HEMTs), which utilizes 2D electron gas (2DEG) as transport channel and exhibits very high electron mobility over traditional field-effect transistors (FETs). Recently, organic electronics have made very rapid progress and the band transport model is demonstrated to be more suitable for explaining carrier behavior in high-mobility crystalline organic materials. Therefore, there emerges a chance for applying energy-band engineering in organic semiconductors to tailor their optoelectronic properties. Here, the idea of energy-band engineering is introduced and a novel device configuration is constructed, i.e., using quantum well structures as active layers in organic FETs, to realize organic 2DEG. Under the control of gate voltage, electron carriers are accumulated and confined at quantized energy levels, and show efficient 2D transport. The electron mobility is up to 10 cm 2 V -1 s -1 , and the operation mechanisms of organic HEMTs are also argued. Our results demonstrate the validity of tailoring optoelectronic properties of organic semiconductors by energy-band engineering, offering a promising way for the step forward of organic electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mobile Computing and Ubiquitous Networking: Concepts, Technologies and Challenges.

Science.gov (United States)

Pierre, Samuel

2001-01-01

Analyzes concepts, technologies and challenges related to mobile computing and networking. Defines basic concepts of cellular systems. Describes the evolution of wireless technologies that constitute the foundations of mobile computing and ubiquitous networking. Presents characterization and issues of mobile computing. Analyzes economical and…

Recycling of WEEE: Characterization of spent printed circuit boards from mobile phones and computers

International Nuclear Information System (INIS)

Yamane, Luciana Harue; Tavares de Moraes, Viviane; Crocce Romano Espinosa, Denise; Soares Tenorio, Jorge Alberto

2011-01-01

Highlights: → This paper presents new and important data on characterization of wastes of electric and electronic equipments. → Copper concentration is increasing in mobile phones and remaining constant in personal computers. → Printed circuit boards from mobile phones and computers would not be mixed prior treatment. - Abstract: This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineral processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results

Wireless-Uplinks-Based Energy-Efficient Scheduling in Mobile Cloud Computing

OpenAIRE

Xing Liu; Chaowei Yuan; Zhen Yang; Enda Peng

2015-01-01

Mobile cloud computing (MCC) combines cloud computing and mobile internet to improve the computational capabilities of resource-constrained mobile devices (MDs). In MCC, mobile users could not only improve the computational capability of MDs but also save operation consumption by offloading the mobile applications to the cloud. However, MCC faces the problem of energy efficiency because of time-varying channels when the offloading is being executed. In this paper, we address the issue of ener...

Thermal electron mobilities in low density gaseous mixtures

International Nuclear Information System (INIS)

Dmitriev, O.W.; Tchorzewska, W.; Szamrej, I.; Forys, M.

1992-01-01

A new method of obtaining thermal electron mobilities from experimental dependencies observed in the electron swarm is described; the method is suitable for both electron accepting and non-accepting systems. The electron mobilities for CO 2 , CH 4 C 2 H 6 as well as for N 2 , Ar, Xe, Kr and their mixtures with carbon dioxide are obtained. (Author)

Efficient electronic entanglement concentration assisted by single mobile electrons

International Nuclear Information System (INIS)

Sheng Yu-Bo; Zhou Lan

2013-01-01

We present an efficient entanglement concentration protocol (ECP) for mobile electrons with charge detection. This protocol is quite different from other ECPs for one can obtain a maximally entangled pair from a pair of less-entangled state and a single mobile electron with a certain probability. With the help of charge detection, it can be repeated to reach a higher success probability. It also does not need to know the coefficient of the original less-entangled states. All these advantages may make this protocol useful in current distributed quantum information processing

ELECTRONIC EVIDENCE IN THE JUDICIAL PROCEEDINGS AND COMPUTER FORENSIC ANALYSIS

Directory of Open Access Journals (Sweden)

Marija Boban

2017-01-01

Full Text Available Today’s perspective of the information society is characterized by the terminology of modern dictionaries of globalization including the terms such as convergence, digitization (media, technology and/or telecommunications and mobility of people or technology. Each word with progress, development, a positive sign of the rise of the information society. On the other hand in a virtual environment traditional evidence in judicial proceedings with the document on paper substrate, are becoming electronic evidence, and their management processes and criteria for admissibility are changing over traditional evidence. The rapid growth of computer data created new opportunities and the growth of new forms of computing, and cyber crime, but also the new ways of proof in court cases, which were unavailable just a few decades. The authors of this paper describe new trends in the development of the information society and the emergence of electronic evidence, with emphasis on the impact of the development of computer crime on electronic evidence; the concept, legal regulation and probative value of electronic evidence, and in particular of electronic documents; and the issue of electronic evidence expertise and electronic documents in court proceedings.

INTERFACE ELECTRONIC MEDICAL CARD ON MOBILE DEVICE

Directory of Open Access Journals (Sweden)

Y. L. Nechyporenko

2013-05-01

Full Text Available The concept designed by electronic medical card for heterogeneous environment of medical information systems at various levels. Appropriate model and technical solution. Done evaluating operating systems for mobile devices. Designed and produced by the project mobile application on Android OS as an electronic medical record on a Tablet PC Acer.

76 FR 41522 - In the Matter of Certain Electronic Devices, Including Mobile Phones, Mobile Tablets, Portable...

Science.gov (United States)

2011-07-14

... Devices, Including Mobile Phones, Mobile Tablets, Portable Music Players, and Computers, and Components.... 1337, in the importation, sale for importation and sale within the United States after importation of certain mobile phones, mobile tablets, portable music players, and computers. 76 FR 24051 (Apr. 29, 2011...

Electron mobility variance in the presence of an electric field: Electron-phonon field-induced tunnel scattering

International Nuclear Information System (INIS)

Melkonyan, S.V.

2012-01-01

The problem of electron mobility variance is discussed. It is established that in equilibrium semiconductors the mobility variance is infinite. It is revealed that the cause of the mobility variance infinity is the threshold of phonon emission. The electron-phonon interaction theory in the presence of an electric field is developed. A new mechanism of electron scattering, called electron-phonon field-induced tunnel (FIT) scattering, is observed. The effect of the electron-phonon FIT scattering is explained in terms of penetration of the electron wave function into the semiconductor band gap in the presence of an electric field. New and more general expressions for the electron-non-polar optical phonon scattering probability and relaxation time are obtained. The results show that FIT transitions have principle meaning for the mobility fluctuation theory: mobility variance becomes finite.

Minimal mobile human computer interaction

NARCIS (Netherlands)

el Ali, A.

2013-01-01

In the last 20 years, the widespread adoption of personal, mobile computing devices in everyday life, has allowed entry into a new technological era in Human Computer Interaction (HCI). The constant change of the physical and social context in a user's situation made possible by the portability of

Agile Development of Various Computational Power Adaptive Web-Based Mobile-Learning Software Using Mobile Cloud Computing

Science.gov (United States)

Zadahmad, Manouchehr; Yousefzadehfard, Parisa

2016-01-01

Mobile Cloud Computing (MCC) aims to improve all mobile applications such as m-learning systems. This study presents an innovative method to use web technology and software engineering's best practices to provide m-learning functionalities hosted in a MCC-learning system as service. Components hosted by MCC are used to empower developers to create…

Is mobile learning a substitute for electronic learning?

OpenAIRE

Sitthiworachart, Jirarat; Joy, Mike

2008-01-01

Mobile learning is widely regarded as the next generation of learning technologies, and refers to the use of mobile devices in education to enhance learning activities. The increasing use of mobile devices has encouraged research into the capabilities of mobile learning systems. Many questions arise about mobile learning, such as whether mobile learning can be a substitute for electronic learning, what the potential benefits and problems of utilizing mobile devices in education are, and what ...

Capturing and analyzing wheelchair maneuvering patterns with mobile cloud computing.

Science.gov (United States)

Fu, Jicheng; Hao, Wei; White, Travis; Yan, Yuqing; Jones, Maria; Jan, Yih-Kuen

2013-01-01

Power wheelchairs have been widely used to provide independent mobility to people with disabilities. Despite great advancements in power wheelchair technology, research shows that wheelchair related accidents occur frequently. To ensure safe maneuverability, capturing wheelchair maneuvering patterns is fundamental to enable other research, such as safe robotic assistance for wheelchair users. In this study, we propose to record, store, and analyze wheelchair maneuvering data by means of mobile cloud computing. Specifically, the accelerometer and gyroscope sensors in smart phones are used to record wheelchair maneuvering data in real-time. Then, the recorded data are periodically transmitted to the cloud for storage and analysis. The analyzed results are then made available to various types of users, such as mobile phone users, traditional desktop users, etc. The combination of mobile computing and cloud computing leverages the advantages of both techniques and extends the smart phone's capabilities of computing and data storage via the Internet. We performed a case study to implement the mobile cloud computing framework using Android smart phones and Google App Engine, a popular cloud computing platform. Experimental results demonstrated the feasibility of the proposed mobile cloud computing framework.

Biomechanical effects of mobile computer location in a vehicle cab.

Science.gov (United States)

Saginus, Kyle A; Marklin, Richard W; Seeley, Patricia; Simoneau, Guy G; Freier, Stephen

2011-10-01

The objective of this research is to determine the best location to place a conventional mobile computer supported by a commercially available mount in a light truck cab. U.S. and Canadian electric utility companies are in the process of integrating mobile computers into their fleet vehicle cabs. There are no publications on the effect of mobile computer location in a vehicle cab on biomechanical loading, performance, and subjective assessment. The authors tested four locations of mobile computers in a light truck cab in a laboratory study to determine how location affected muscle activity of the lower back and shoulders; joint angles of the shoulders, elbows, and wrist; user performance; and subjective assessment. A total of 22 participants were tested in this study. Placing the mobile computer closer to the steering wheel reduced low back and shoulder muscle activity. Joint angles of the shoulders, elbows, and wrists were also closer to neutral angle. Biomechanical modeling revealed substantially less spinal compression and trunk muscle force. In general, there were no practical differences in performance between the locations. Subjective assessment indicated that users preferred the mobile computer to be as close as possible to the steering wheel. Locating the mobile computer close to the steering wheel reduces risk of injuries, such as low back pain and shoulder tendonitis. Results from the study can guide electric utility companies in the installation of mobile computers into vehicle cabs. Results may also be generalized to other industries that use trucklike vehicles, such as construction.

Supporting Privacy of Computations in Mobile Big Data Systems

Directory of Open Access Journals (Sweden)

Sriram Nandha Premnath

2016-05-01

Full Text Available Cloud computing systems enable clients to rent and share computing resources of third party platforms, and have gained widespread use in recent years. Numerous varieties of mobile, small-scale devices such as smartphones, red e-health devices, etc., across users, are connected to one another through the massive internetwork of vastly powerful servers on the cloud. While mobile devices store “private information” of users such as location, payment, health data, etc., they may also contribute “semi-public information” (which may include crowdsourced data such as transit, traffic, nearby points of interests, etc. for data analytics. In such a scenario, a mobile device may seek to obtain the result of a computation, which may depend on its private inputs, crowdsourced data from other mobile devices, and/or any “public inputs” from other servers on the Internet. We demonstrate a new method of delegating real-world computations of resource-constrained mobile clients using an encrypted program known as the garbled circuit. Using the garbled version of a mobile client’s inputs, a server in the cloud executes the garbled circuit and returns the resulting garbled outputs. Our system assures privacy of the mobile client’s input data and output of the computation, and also enables the client to verify that the evaluator actually performed the computation. We analyze the complexity of our system. We measure the time taken to construct the garbled circuit as well as evaluate it for varying number of servers. Using real-world data, we evaluate our system for a practical, privacy preserving search application that locates the nearest point of interest for the mobile client to demonstrate feasibility.

A Lightweight Distributed Framework for Computational Offloading in Mobile Cloud Computing

Science.gov (United States)

Shiraz, Muhammad; Gani, Abdullah; Ahmad, Raja Wasim; Adeel Ali Shah, Syed; Karim, Ahmad; Rahman, Zulkanain Abdul

2014-01-01

The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs). Therefore, Mobile Cloud Computing (MCC) leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC. PMID:25127245

A lightweight distributed framework for computational offloading in mobile cloud computing.

Directory of Open Access Journals (Sweden)

Muhammad Shiraz

Full Text Available The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs. Therefore, Mobile Cloud Computing (MCC leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC.

Cross-field Mobility in a Pure Electron Plasma

International Nuclear Information System (INIS)

Fossum, E.C.; King, L.B.

2006-01-01

An electron trapping apparatus was constructed in order to study electron dynamics in the defining electric and magnetic field of a Hall-effect thruster. The approach presented here decouples the cross-field mobility from plasma effects by conducting measurements on a pure electron plasma in a highly controlled environment. Dielectric walls are removed completely eliminating all wall effect; thus, electrons are confined solely by a radial magnetic field and a crossed, independently-controlled, axial electric field that induces the closed-drift azimuthal Hall current. Electron trajectories and cross-field mobility were examined in response to electric and magnetic field strength and background neutral density

Developing and validating an instrument for measuring mobile computing self-efficacy.

Science.gov (United States)

Wang, Yi-Shun; Wang, Hsiu-Yuan

2008-08-01

IT-related self-efficacy has been found to have a critical influence on system use. However, traditional measures of computer self-efficacy and Internet-related self-efficacy are perceived to be inapplicable in the context of mobile computing and commerce because they are targeted primarily at either desktop computer or wire-based technology contexts. Based on previous research, this study develops and validates a multidimensional instrument for measuring mobile computing self-efficacy (MCSE). This empirically validated instrument will be useful to researchers in developing and testing the theories of mobile user behavior, and to practitioners in assessing the mobile computing self-efficacy of users and promoting the use of mobile commerce systems.

Replicated Data Management for Mobile Computing

CERN Document Server

Douglas, Terry

2008-01-01

Managing data in a mobile computing environment invariably involves caching or replication. In many cases, a mobile device has access only to data that is stored locally, and much of that data arrives via replication from other devices, PCs, and services. Given portable devices with limited resources, weak or intermittent connectivity, and security vulnerabilities, data replication serves to increase availability, reduce communication costs, foster sharing, and enhance survivability of critical information. Mobile systems have employed a variety of distributed architectures from client-server

Social influence model and electronic word of mouth: PC versus mobile internet

OpenAIRE

Okazaki, Shintaro

2009-01-01

Compared with laptop or desktop computers, mobile devices offer greater flexibility in time and space, thus enabling consumers to be connected online more continually. In addition, their small size, portability and ease of use with location-based capabilities facilitate sending and receiving timely information in the right place. Drawing upon a social influence model proposed by Dholakia et al. (2004), this paper proposes a causal model for consumer participation in electronic ...

Fair Secure Computation with Reputation Assumptions in the Mobile Social Networks

Directory of Open Access Journals (Sweden)

Yilei Wang

2015-01-01

Full Text Available With the rapid development of mobile devices and wireless technologies, mobile social networks become increasingly available. People can implement many applications on the basis of mobile social networks. Secure computation, like exchanging information and file sharing, is one of such applications. Fairness in secure computation, which means that either all parties implement the application or none of them does, is deemed as an impossible task in traditional secure computation without mobile social networks. Here we regard the applications in mobile social networks as specific functions and stress on the achievement of fairness on these functions within mobile social networks in the presence of two rational parties. Rational parties value their utilities when they participate in secure computation protocol in mobile social networks. Therefore, we introduce reputation derived from mobile social networks into the utility definition such that rational parties have incentives to implement the applications for a higher utility. To the best of our knowledge, the protocol is the first fair secure computation in mobile social networks. Furthermore, it finishes within constant rounds and allows both parties to know the terminal round.

Increase in electron mobility of InGaAs/InP composite channel high electron mobility transistor structure due to SiN passivation

International Nuclear Information System (INIS)

Liu Yuwei; Wang Hong; Radhakrishnan, K.

2007-01-01

The influence of silicon nitride passivation on electron mobility of InGaAs/InP composite channel high electron mobility transistor structure has been studied. Different from the structures with single InGaAs channel, an increase in effective mobility μ e with a negligible change of sheet carrier density n s after SiN deposition is clearly observed in the composite channel structures. The enhancement of μ e could be explained under the framework of electrons transferring from the InP sub-channel into InGaAs channel region due to the energy band bending at the surface region caused by SiN passivation, which is further confirmed by low temperature photoluminescence measurements

Exact solution of a coupled spin–electron linear chain composed of localized Ising spins and mobile electrons

International Nuclear Information System (INIS)

Čisárová, Jana; Strečka, Jozef

2014-01-01

Exact solution of a coupled spin–electron linear chain composed of localized Ising spins and mobile electrons is found. The investigated spin–electron model is exactly solvable by the use of a transfer-matrix method after tracing out the degrees of freedom of mobile electrons delocalized over a couple of interstitial (decorating) sites. The exact ground-state phase diagram reveals an existence of five phases with different number of mobile electrons per unit cell, two of which are ferromagnetic, two are paramagnetic and one is antiferromagnetic. We have studied in particular the dependencies of compressibility and specific heat on temperature and electron density. - Highlights: • A coupled spin–electron chain composed of Ising spins and mobile electrons is exactly solved. • Quantum paramagnetic, ferromagnetic and antiferromagnetic ground states are found. • A compressibility shows a non-monotonous dependence on temperature and electron density. • Thermal dependences of specific heat display two distinct peaks

Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry (PE-EA-IMS)

International Nuclear Information System (INIS)

Su, Desheng; Niu, Wenqi; Liu, Sheng; Shen, Chengyin; Huang, Chaoqun; Wang, Hongmei; Jiang, Haihe; Chu, Yannan

2012-01-01

Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature. - Highlights: ► Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS) was developed to study electron attachment reaction. ► The rate constants of electron attachment to CCl 4 and CHCl 3 were determined. ► The present experimental results are in good agreement with the previously reported data.

Using AMDD method for Database Design in Mobile Cloud Computing Systems

OpenAIRE

Silviu Claudiu POPA; Mihai-Constantin AVORNICULUI; Vasile Paul BRESFELEAN

2013-01-01

The development of the technologies of wireless telecommunications gave birth of new kinds of e-commerce, the so called Mobile e-Commerce or m-Commerce. Mobile Cloud Computing (MCC) represents a new IT research area that combines mobile computing and cloud compu-ting techniques. Behind a cloud mobile commerce system there is a database containing all necessary information for transactions. By means of Agile Model Driven Development (AMDD) method, we are able to achieve many benefits that smoo...

Mobile computing device configured to compute irradiance, glint, and glare of the sun

Science.gov (United States)

Gupta, Vipin P; Ho, Clifford K; Khalsa, Siri Sahib

2014-03-11

Described herein are technologies pertaining to computing the solar irradiance distribution on a surface of a receiver in a concentrating solar power system or glint/glare emitted from a reflective entity. A mobile computing device includes at least one camera that captures images of the Sun and the entity of interest, wherein the images have pluralities of pixels having respective pluralities of intensity values. Based upon the intensity values of the pixels in the respective images, the solar irradiance distribution on the surface of the entity or glint/glare corresponding to the entity is computed by the mobile computing device.

Wireless-Uplinks-Based Energy-Efficient Scheduling in Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Xing Liu

2015-01-01

Full Text Available Mobile cloud computing (MCC combines cloud computing and mobile internet to improve the computational capabilities of resource-constrained mobile devices (MDs. In MCC, mobile users could not only improve the computational capability of MDs but also save operation consumption by offloading the mobile applications to the cloud. However, MCC faces the problem of energy efficiency because of time-varying channels when the offloading is being executed. In this paper, we address the issue of energy-efficient scheduling for wireless uplink in MCC. By introducing Lyapunov optimization, we first propose a scheduling algorithm that can dynamically choose channel to transmit data based on queue backlog and channel statistics. Then, we show that the proposed scheduling algorithm can make a tradeoff between queue backlog and energy consumption in a channel-aware MCC system. Simulation results show that the proposed scheduling algorithm can reduce the time average energy consumption for offloading compared to the existing algorithm.

A mobile and portable trusted computing platform

Directory of Open Access Journals (Sweden)

Nepal Surya

2011-01-01

Full Text Available Abstract The mechanism of establishing trust in a computing platform is tightly coupled with the characteristics of a specific machine. This limits the portability and mobility of trust as demanded by many emerging applications that go beyond the organizational boundaries. In order to address this problem, we propose a mobile and portable trusted computing platform in a form of a USB device. First, we describe the design and implementation of the hardware and software architectures of the device. We then demonstrate the capabilities of the proposed device by developing a trusted application.

Computer vision for an autonomous mobile robot

CSIR Research Space (South Africa)

Withey, Daniel J

2015-10-01

Full Text Available Computer vision systems are essential for practical, autonomous, mobile robots – machines that employ artificial intelligence and control their own motion within an environment. As with biological systems, computer vision systems include the vision...

Impacts of mobile tablet computing on provider productivity, communications, and the process of care.

Science.gov (United States)

Schooley, Benjamin; Walczak, Steven; Hikmet, Neset; Patel, Nitin

2016-04-01

Health information technology investments continue to increase while the value derived from their implementation and use is mixed. Mobile device adoption into practice is a recent trend that has increased dramatically and formal studies are needed to investigate consequent benefits and challenges. The objective of this study is to evaluate practitioner perceptions of improvements in productivity, provider-patient communications, care provision, technology usability and other outcomes following the adoption and use of a tablet computer connected to electronic health information resources. A pilot program was initiated in June 2013 to evaluate the effect of mobile tablet computers at one health provider organization in the southeast United States. Providers were asked to volunteer for the evaluation and were each given a mobile tablet computer. A total of 42 inpatient and outpatient providers were interviewed in 2015 using a survey style questionnaire that utilized yes/no, Likert-style, and open ended questions. Each had previously used an electronic health record (EHR) system a minimum of one year outside of residency, and were regular users of personal mobile devices. Each used a mobile tablet computer in the context of their practice connected to the health system EHR. The survey results indicate that more than half of providers perceive the use of the tablet device as having a positive effect on patient communications, patient education, patient's perception of the provider, time spent interacting with patients, provider productivity, process of care, satisfaction with EHR when used together with the device, and care provision. Providers also reported feeling comfortable using the device (82.9%), would recommend the device to colleagues (69.2%), did not experience increased information security and privacy concerns (95%), and noted significant reductions in EHR login times (64.1%). Less than 25% of participants reported negative impacts on any of these areas as

Performance Evaluation of a Mobile Wireless Computational Grid ...

African Journals Online (AJOL)

PROF. OLIVER OSUAGWA

2015-12-01

Dec 1, 2015 ... Abstract. This work developed and simulated a mathematical model for a mobile wireless computational Grid ... which mobile modes will process the tasks .... evaluation are analytical modelling, simulation ... MATLAB 7.10.0.

Energy-Aware Computation Offloading of IoT Sensors in Cloudlet-Based Mobile Edge Computing.

Science.gov (United States)

Ma, Xiao; Lin, Chuang; Zhang, Han; Liu, Jianwei

2018-06-15

Mobile edge computing is proposed as a promising computing paradigm to relieve the excessive burden of data centers and mobile networks, which is induced by the rapid growth of Internet of Things (IoT). This work introduces the cloud-assisted multi-cloudlet framework to provision scalable services in cloudlet-based mobile edge computing. Due to the constrained computation resources of cloudlets and limited communication resources of wireless access points (APs), IoT sensors with identical computation offloading decisions interact with each other. To optimize the processing delay and energy consumption of computation tasks, theoretic analysis of the computation offloading decision problem of IoT sensors is presented in this paper. In more detail, the computation offloading decision problem of IoT sensors is formulated as a computation offloading game and the condition of Nash equilibrium is derived by introducing the tool of a potential game. By exploiting the finite improvement property of the game, the Computation Offloading Decision (COD) algorithm is designed to provide decentralized computation offloading strategies for IoT sensors. Simulation results demonstrate that the COD algorithm can significantly reduce the system cost compared with the random-selection algorithm and the cloud-first algorithm. Furthermore, the COD algorithm can scale well with increasing IoT sensors.

Spontaneous ad hoc mobile cloud computing network.

Science.gov (United States)

Lacuesta, Raquel; Lloret, Jaime; Sendra, Sandra; Peñalver, Lourdes

2014-01-01

Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes.

Innovative Mobile Platform Developments for Electronic Services Design and Delivery

DEFF Research Database (Denmark)

Scupola, Ada

In the ever-growing world of technology, it is becoming more important to understand the developments of new electronic services and mobile applications. Innovative Mobile Platform Developments for Electronic Services Design, and Delivery is a comprehensive look at all aspects of production manag...

SPICE compatible analytical electron mobility model for biaxial strained-Si-MOSFETs

Energy Technology Data Exchange (ETDEWEB)

Chaudhry, Amit; Sangwan, S. [UIET, Panjab University, Chandigarh (India); Roy, J. N., E-mail: amit_chaudhry01@yahoo.com [Solar Semiconductro Pvt. Ltd, Hyderabad (India)

2011-05-15

This paper describes an analytical model for bulk electron mobility in strained-Si layers as a function of strain. Phonon scattering, columbic scattering and surface roughness scattering are included to analyze the full mobility model. Analytical explicit calculations of all of the parameters to accurately estimate the electron mobility have been made. The results predict an increase in the electron mobility with the application of biaxial strain as also predicted from the basic theory of strain physics of metal oxide semiconductor (MOS) devices. The results have also been compared with numerically reported results and show good agreement. (semiconductor devices)

SPICE compatible analytical electron mobility model for biaxial strained-Si-MOSFETs

International Nuclear Information System (INIS)

Chaudhry, Amit; Sangwan, S.; Roy, J. N.

2011-01-01

This paper describes an analytical model for bulk electron mobility in strained-Si layers as a function of strain. Phonon scattering, columbic scattering and surface roughness scattering are included to analyze the full mobility model. Analytical explicit calculations of all of the parameters to accurately estimate the electron mobility have been made. The results predict an increase in the electron mobility with the application of biaxial strain as also predicted from the basic theory of strain physics of metal oxide semiconductor (MOS) devices. The results have also been compared with numerically reported results and show good agreement. (semiconductor devices)

Mobile Imaging and Computing for Intelligent Structural Damage Inspection

Directory of Open Access Journals (Sweden)

ZhiQiang Chen

2014-01-01

Full Text Available Optical imaging is a commonly used technique in civil engineering for aiding the archival of damage scenes and more recently for image analysis-based damage quantification. However, the limitations are evident when applying optical imaging in the field. The most significant one is the lacking of computing and processing capability in the real time. The advancement of mobile imaging and computing technologies provides a promising opportunity to change this norm. This paper first provides a timely introduction of the state-of-the-art mobile imaging and computing technologies for the purpose of engineering application development. Further we propose a mobile imaging and computing (MIC framework for conducting intelligent condition assessment for constructed objects, which features in situ imaging and real-time damage analysis. This framework synthesizes advanced mobile technologies with three innovative features: (i context-enabled image collection, (ii interactive image preprocessing, and (iii real-time image analysis and analytics. Through performance evaluation and field experiments, this paper demonstrates the feasibility and efficiency of the proposed framework.

Electronic Discharge Letter Mobile App

NARCIS (Netherlands)

Lezcano, Leonardo; Triana, Michel; Ternier, Stefaan; Hartkopf, Kathleen; Stieger, Lina; Schroeder, Hanna; Sopka, Sasa; Drachsler, Hendrik; Maher, Bridget; Henn, Patrick; Orrego, Carola; Specht, Marcus

2014-01-01

The electronic discharge letter mobile app takes advantage of Near Field Communication (NFC) within the PATIENT project and a related post-doc study. NFC enabled phones to read passive RFID tags, but can also use this short-range wireless technology to exchange (small) messages. NFC in that sense

FAULT TOLERANCE IN MOBILE GRID COMPUTING

OpenAIRE

Aghila Rajagopal; M.A. Maluk Mohamed

2014-01-01

This paper proposes a novel model for Surrogate Object based paradigm in mobile grid environment for achieving a Fault Tolerance. Basically Mobile Grid Computing Model focuses on Service Composition and Resource Sharing Process. In order to increase the performance of the system, Fault Recovery plays a vital role. In our Proposed System for Recovery point, Surrogate Object Based Checkpoint Recovery Model is introduced. This Checkpoint Recovery model depends on the Surrogate Object and the Fau...

The quasi-ballistic model of electron mobility in liquid hydrocarbons

International Nuclear Information System (INIS)

Mozumder, A.

1996-01-01

A phenomenological theory of low-mobility liquid hydrocarbons is developed which includes electron ballistic motion in the quasi-free state, in competition with diffusion and trapping. For most low-mobility liquids the theory predicts consistently the effective mobility and activation energy, in agreement with experiments, using quasi-free mobility and trap density respectively as ∼ 100 cm 2 v -1 s -1 and ∼ 10 19 cm -3 . Field dependence of mobility if theoretically of quadratic type for relatively small fields, agreeing approximately with experimental data for n-hexane. Electron scavenging with ''good'' scavengers occurs via the quasi-free state at nearly diffusion-controlled rate; however the effect of large mean free path is seen clearly. (author)

First-principles method for electron-phonon coupling and electron mobility

DEFF Research Database (Denmark)

Gunst, Tue; Markussen, Troels; Stokbro, Kurt

2016-01-01

We present density functional theory calculations of the phonon-limited mobility in n-type monolayer graphene, silicene, and MoS2. The material properties, including the electron-phonon interaction, are calculated from first principles. We provide a detailed description of the normalized full......-band relaxation time approximation for the linearized Boltzmann transport equation (BTE) that includes inelastic scattering processes. The bulk electron-phonon coupling is evaluated by a supercell method. The method employed is fully numerical and does therefore not require a semianalytic treatment of part...... of the problem and, importantly, it keeps the anisotropy information stored in the coupling as well as the band structure. In addition, we perform calculations of the low-field mobility and its dependence on carrier density and temperature to obtain a better understanding of transport in graphene, silicene...

Design, Development, and Evaluation of a Mobile Learning Application for Computing Education

Science.gov (United States)

Oyelere, Solomon Sunday; Suhonen, Jarkko; Wajiga, Greg M.; Sutinen, Erkki

2018-01-01

The study focused on the application of the design science research approach in the course of developing a mobile learning application, MobileEdu, for computing education in the Nigerian higher education context. MobileEdu facilitates the learning of computer science courses on mobile devices. The application supports ubiquitous, collaborative,…

A Scheme for Verification on Data Integrity in Mobile Multicloud Computing Environment

Directory of Open Access Journals (Sweden)

Laicheng Cao

2016-01-01

Full Text Available In order to verify the data integrity in mobile multicloud computing environment, a MMCDIV (mobile multicloud data integrity verification scheme is proposed. First, the computability and nondegeneracy of verification can be obtained by adopting BLS (Boneh-Lynn-Shacham short signature scheme. Second, communication overhead is reduced based on HVR (Homomorphic Verifiable Response with random masking and sMHT (sequence-enforced Merkle hash tree construction. Finally, considering the resource constraints of mobile devices, data integrity is verified by lightweight computing and low data transmission. The scheme improves shortage that mobile device communication and computing power are limited, it supports dynamic data operation in mobile multicloud environment, and data integrity can be verified without using direct source file block. Experimental results also demonstrate that this scheme can achieve a lower cost of computing and communications.

Surface roughness induced electron mobility degradation in InAs nanowires

International Nuclear Information System (INIS)

Wang Fengyun; Yip, Sen Po; Han, Ning; Fok, KitWa; Lin, Hao; Hou, Jared J; Dong, Guofa; Hung, Tak Fu; Chan, K S; Ho, Johnny C

2013-01-01

In this work, we present a study of the surface roughness dependent electron mobility in InAs nanowires grown by the nickel-catalyzed chemical vapor deposition method. These nanowires have good crystallinity, well-controlled surface morphology without any surface coating or tapering and an excellent peak field-effect mobility up to 15 000 cm 2 V −1 s −1 when configured into back-gated field-effect nanowire transistors. Detailed electrical characterizations reveal that the electron mobility degrades monotonically with increasing surface roughness and diameter scaling, while low-temperature measurements further decouple the effects of surface/interface traps and phonon scattering, highlighting the dominant impact of surface roughness scattering on the electron mobility for miniaturized and surface disordered nanowires. All these factors suggest that careful consideration of nanowire geometries and surface condition is required for designing devices with optimal performance. (paper)

The Social & Mobile Learning Experiences of Students Using Mobile E-Books

Science.gov (United States)

Kissinger, Jeff S.

2013-01-01

This research was designed to explore the learning experiences of state college students using mobile electronic textbook (e-book) readers. The purpose of the study was to build a rich description of how students used e-books delivered on mobile computing devices for college-level, introductory

Empirical electron cross-field mobility in a Hall effect thruster

International Nuclear Information System (INIS)

Garrigues, L.; Perez-Luna, J.; Lo, J.; Hagelaar, G. J. M.; Boeuf, J. P.; Mazouffre, S.

2009-01-01

Electron transport across the magnetic field in Hall effect thrusters is still an open question. Models have so far assumed 1/B 2 or 1/B scaling laws for the 'anomalous' electron mobility, adjusted to reproduce the integrated performance parameters of the thruster. We show that models based on such mobility laws predict very different ion velocity distribution functions (IVDF) than measured by laser induced fluorescence (LIF). A fixed spatial mobility profile, obtained by analysis of improved LIF measurements, leads to much better model predictions of thruster performance and IVDF than 1/B 2 or 1/B mobility laws for discharge voltages in the 500-700 V range.

Growth parameter optimization and interface treatment for enhanced electron mobility in heavily strained GaInAs/AlInAs high electron mobility transistor structures

International Nuclear Information System (INIS)

Fedoryshyn, Yuriy; Ostinelli, Olivier; Alt, Andreas; Pallin, Angel; Bolognesi, Colombo R.

2014-01-01

The optimization of heavily strained Ga 0.25 In 0.75 As/Al 0.48 In 0.52 As high electron mobility transistor structures is discussed in detail. The growth parameters and the channel layer interfaces were optimized in order to maximize the mobility of the two-dimensional electron gas. Structures composed of an 11 nm thick channel layer and a 4 nm thick spacer layer exhibited electron mobilities as high as 15 100 cm 2 /Vs and 70 000 cm 2 /Vs at 300 and 77 K, respectively, for channels including InAs strained layers. The sheet carrier density was kept above 2.5 × 10 12  cm −2 throughout the entire study

Development of mobile electronic health records application in a secondary general hospital in Korea.

Science.gov (United States)

Choi, Wookjin; Park, Min Ah; Hong, Eunseok; Kim, Sunhyu; Ahn, Ryeok; Hong, Jungseok; Song, Seungyeol; Kim, Tak; Kim, Jeongkeun; Yeo, Seongwoon

2013-12-01

The recent evolution of mobile devices has opened new possibilities of providing strongly integrated mobile services in healthcare. The objective of this paper is to describe the decision driver, development, and implementation of an integrated mobile Electronic Health Record (EHR) application at Ulsan University Hospital. This application helps healthcare providers view patients' medical records and information without a stationary computer workstation. We developed an integrated mobile application prototype that aimed to improve the mobility and usability of healthcare providers during their daily medical activities. The Android and iOS platform was used to create the mobile EHR application. The first working version was completed in 5 months and required 1,080 development hours. The mobile EHR application provides patient vital signs, patient data, text communication, and integrated EHR. The application allows our healthcare providers to know the status of patients within and outside the hospital environment. The application provides a consistent user environment on several compatible Android and iOS devices. A group of 10 beta testers has consistently used and maintained our copy of the application, suggesting user acceptance. We are developing the integrated mobile EHR application with the goals of implementing an environment that is user-friendly, implementing a patient-centered system, and increasing the hospital's competitiveness.

Expertik: Experience with Artificial Intelligence and Mobile Computing

Directory of Open Access Journals (Sweden)

José Edward Beltrán Lozano

2013-06-01

Full Text Available This article presents the experience in the development of services based in Artificial Intelligence, Service Oriented Architecture, mobile computing. It aims to combine technology offered by mobile computing provides techniques and artificial intelligence through a service provide diagnostic solutions to problems in industrial maintenance. It aims to combine technology offered by mobile computing and the techniques artificial intelligence through a service to provide diagnostic solutions to problems in industrial maintenance. For service creation are identified the elements of an expert system, the knowledge base, the inference engine and knowledge acquisition interfaces and their consultation. The applications were developed in ASP.NET under architecture three layers. The data layer was developed conjunction in SQL Server with data management classes; business layer in VB.NET and the presentation layer in ASP.NET with XHTML. Web interfaces for knowledge acquisition and query developed in Web and Mobile Web. The inference engine was conducted in web service developed for the fuzzy logic model to resolve requests from applications consulting knowledge (initially an exact rule-based logic within this experience to resolve requests from applications consulting knowledge. This experience seeks to strengthen a technology-based company to offer services based on AI for service companies Colombia.

MOMCC: Market-Oriented Architecture for Mobile Cloud Computing Based on Service Oriented Architecture

OpenAIRE

Abolfazli, Saeid; Sanaei, Zohreh; Gani, Abdullah; Shiraz, Muhammad

2012-01-01

The vision of augmenting computing capabilities of mobile devices, especially smartphones with least cost is likely transforming to reality leveraging cloud computing. Cloud exploitation by mobile devices breeds a new research domain called Mobile Cloud Computing (MCC). However, issues like portability and interoperability should be addressed for mobile augmentation which is a non-trivial task using component-based approaches. Service Oriented Architecture (SOA) is a promising design philosop...

The Proliferation of Smart Devices on Mobile Cloud Computing

DEFF Research Database (Denmark)

Kant Hiran, Kamal; Doshi, Ruchi

Mobile Cloud Computing (MCC) is an emerging research topic in the world of Information Technology, this trend promises to deliver and promote a wide range of advantage to it anxious markets or clients. With MCC, all the applications that exist are on a remote server enable the individual client...... machines or devices to access them. Mobile Cloud Computing in smartphone and tablets allows devices to offload functions and data resources to a cloud environment. This happening conserve the power of the smart devices or the tablets to prolong it battery longevity. This book sought to analyses how MCC...... influence the time they spend on their devices. This book would be useful for research scholars as a text for university undergraduate courses related to mobile cloud computing, as well as at junior colleges, and vocational schools training course....

Micromagnetics on high-performance workstation and mobile computational platforms

Science.gov (United States)

Fu, S.; Chang, R.; Couture, S.; Menarini, M.; Escobar, M. A.; Kuteifan, M.; Lubarda, M.; Gabay, D.; Lomakin, V.

2015-05-01

The feasibility of using high-performance desktop and embedded mobile computational platforms is presented, including multi-core Intel central processing unit, Nvidia desktop graphics processing units, and Nvidia Jetson TK1 Platform. FastMag finite element method-based micromagnetic simulator is used as a testbed, showing high efficiency on all the platforms. Optimization aspects of improving the performance of the mobile systems are discussed. The high performance, low cost, low power consumption, and rapid performance increase of the embedded mobile systems make them a promising candidate for micromagnetic simulations. Such architectures can be used as standalone systems or can be built as low-power computing clusters.

Enhanced mobility in vertically scaled N-polar high-electron-mobility transistors using GaN/InGaN composite channels

Science.gov (United States)

Li, Haoran; Wienecke, Steven; Romanczyk, Brian; Ahmadi, Elaheh; Guidry, Matthew; Zheng, Xun; Keller, Stacia; Mishra, Umesh K.

2018-02-01

A GaN/InGaN composite channel design for vertically scaled N-polar high-electron-mobility transistor (HEMT) structures is proposed and demonstrated by metal-organic chemical vapor deposition. In a conventional N-polar HEMT structure, as the channel thickness (tch) decreases, the sheet charge density (ns) decreases, the electric field in the channel increases, and the centroid of the two-dimensional electron gas (2DEG) moves towards the back-barrier/channel interface, resulting in stronger scattering and lower electron mobility (μ). In this study, a thin InGaN layer was introduced in-between the channel and the AlGaN cap to increase the 2DEG density and reduce the electric field in the channel and therefore increase the electron mobility. The dependence of μ on the InGaN thickness (tInGaN) and the indium composition (xIn) was investigated for different channel thicknesses. With optimized tInGaN and xIn, significant improvements in electron mobility were observed. For a 6 nm channel HEMT structure, the electron mobility increased from 606 to 1141 cm2/(V.s) when the 6 nm thick pure GaN channel was replaced by the 4 nm GaN/2 nm In0.1Ga0.9N composite channel.

The development of mobile computation and the related formal description

International Nuclear Information System (INIS)

Jin Yan; Yang Xiaozong

2003-01-01

The description and research for formal representation in mobile computation, which is very instructive to resolve the status transmission, domain administration, authentication. This paper presents the descriptive communicating process and computational process from the view of formal calculus, what's more, it construct a practical application used by mobile ambient. Finally, this dissertation shows the future work and direction. (authors)

Electron mobility enhancement in (100) oxygen-inserted silicon channel

Energy Technology Data Exchange (ETDEWEB)

Xu, Nuo; King Liu, Tsu-Jae [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Takeuchi, Hideki; Hytha, Marek; Cody, Nyles W.; Stephenson, Robert J.; Mears, Robert J. [Mears Technologies, Inc., Wellesley Hills, Massachusetts 02481 (United States); Kwak, Byungil; Cha, Seon Yong [SK Hynix, Icheon-si, Gyeonggi-do 467-701 (Korea, Republic of)

2015-09-21

High performance improvement (+88% in peak G{sub m} and >30% in linear and saturation region drain currents) was observed for N-MOSFETs with Oxygen-Inserted (OI) Si channel. From TCAD analysis of the C-V measurement data, the improvement was confirmed to be due to electron mobility enhancement of the OI Si channel (+75% at N{sub inv} = 4.0 × 10{sup 12} cm{sup −2} and +25% at N{sub inv} = 8.0 × 10{sup 12} cm{sup −2}). Raman and high-resolution Rutherford backscattering measurements confirmed that negligible strain is induced in the OI Si layer, and hence, it cannot be used to explain the origin of mobility improvement. Poisson-Schrödinger based quantum mechanical simulation was performed, taking into account phonon, surface roughness and Coulomb scatterings. The OI layer was modeled as a “quasi barrier” region with reference to the Si conduction band edge to confine inversion electrons. Simulation explains the measured electron mobility enhancement as the confinement effect of inversion electrons while the formation of an super-steep retrograde well doping profile in the channel (as a result of dopant diffusion blocking effect accompanied by introduction of the OI layer) also contributes 50%–60% of the mobility improvement.

Server-Aided Verification Signature with Privacy for Mobile Computing

Directory of Open Access Journals (Sweden)

Lingling Xu

2015-01-01

Full Text Available With the development of wireless technology, much data communication and processing has been conducted in mobile devices with wireless connection. As we know that the mobile devices will always be resource-poor relative to static ones though they will improve in absolute ability, therefore, they cannot process some expensive computational tasks due to the constrained computational resources. According to this problem, server-aided computing has been studied in which the power-constrained mobile devices can outsource some expensive computation to a server with powerful resources in order to reduce their computational load. However, in existing server-aided verification signature schemes, the server can learn some information about the message-signature pair to be verified, which is undesirable especially when the message includes some secret information. In this paper, we mainly study the server-aided verification signatures with privacy in which the message-signature pair to be verified can be protected from the server. Two definitions of privacy for server-aided verification signatures are presented under collusion attacks between the server and the signer. Then based on existing signatures, two concrete server-aided verification signature schemes with privacy are proposed which are both proved secure.

Enhancement in M-Government and mobile computing in developing countries

CSIR Research Space (South Africa)

Ogunleye, OS

2013-11-01

Full Text Available to the government and the community at large. In this paper, we provide an introduction to the application and new enhancement of mobile technologies and mobile computing in technical government systems. Mobile devices allow allows every citizens to access...

Rational In Silico Design of an Organic Semiconductor with Improved Electron Mobility.

Science.gov (United States)

Friederich, Pascal; Gómez, Verónica; Sprau, Christian; Meded, Velimir; Strunk, Timo; Jenne, Michael; Magri, Andrea; Symalla, Franz; Colsmann, Alexander; Ruben, Mario; Wenzel, Wolfgang

2017-11-01

Organic semiconductors find a wide range of applications, such as in organic light emitting diodes, organic solar cells, and organic field effect transistors. One of their most striking disadvantages in comparison to crystalline inorganic semiconductors is their low charge-carrier mobility, which manifests itself in major device constraints such as limited photoactive layer thicknesses. Trial-and-error attempts to increase charge-carrier mobility are impeded by the complex interplay of the molecular and electronic structure of the material with its morphology. Here, the viability of a multiscale simulation approach to rationally design materials with improved electron mobility is demonstrated. Starting from one of the most widely used electron conducting materials (Alq 3 ), novel organic semiconductors with tailored electronic properties are designed for which an improvement of the electron mobility by three orders of magnitude is predicted and experimentally confirmed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A computational study of the electronic properties of one-dimensional armchair phosphorene nanotubes

Energy Technology Data Exchange (ETDEWEB)

Yu, Sheng; Zhu, Hao; Eshun, Kwesi; Arab, Abbas; Badwan, Ahmad; Li, Qiliang [Department of Electrical and Computer Engineering, George Mason University, Fairfax, Virginia 22033 (United States)

2015-10-28

We have performed a comprehensive first-principle computational study of the electronic properties of one-dimensional phosphorene nanotubes (PNTs), and the strain effect on the mechanical and electrical properties of PNTs, including the elastic modulus, energy bandstructure, and carrier effective mass. The study has demonstrated that the armchair PNTs have semiconducting properties along the axial direction and the carrier mobility can be significantly improved by compressive strain. The hole mobility increases from 40.7 cm{sup 2}/V s to 197.0 cm{sup 2}/V s as the compressive strain increases to −5% at room temperature. The investigations of size effect on armchair PNTs indicated that the conductance increases significantly as the increasing diameter. Overall, this study indicated that the PNTs have very attractive electronic properties for future application in nanomaterials and devices.

High electron mobility in Ga(In)NAs films grown by molecular beam epitaxy

International Nuclear Information System (INIS)

Miyashita, Naoya; Ahsan, Nazmul; Monirul Islam, Muhammad; Okada, Yoshitaka; Inagaki, Makoto; Yamaguchi, Masafumi

2012-01-01

We report the highest mobility values above 2000 cm 2 /Vs in Si doped GaNAs film grown by molecular beam epitaxy. To understand the feature of the origin which limits the electron mobility in GaNAs, temperature dependences of mobility were measured for high mobility GaNAs and referential low mobility GaInNAs. Temperature dependent mobility for high mobility GaNAs is similar to the GaAs case, while that for low mobility GaInNAs shows large decrease in lower temperature region. The electron mobility of high quality GaNAs can be explained by intrinsic limiting factor of random alloy scattering and extrinsic factor of ionized impurity scattering.

FTRA 4th International Conference on Mobile, Ubiquitous, and Intelligent Computing

CERN Document Server

Adeli, Hojjat; Park, Namje; Woungang, Isaac

2014-01-01

MUSIC 2013 will be the most comprehensive text focused on the various aspects of Mobile, Ubiquitous and Intelligent computing. MUSIC 2013 provides an opportunity for academic and industry professionals to discuss the latest issues and progress in the area of intelligent technologies in mobile and ubiquitous computing environment. MUSIC 2013 is the next edition of the 3rd International Conference on Mobile, Ubiquitous, and Intelligent Computing (MUSIC-12, Vancouver, Canada, 2012) which was the next event in a series of highly successful International Workshop on Multimedia, Communication and Convergence technologies MCC-11 (Crete, Greece, June 2011), MCC-10 (Cebu, Philippines, August 2010).

Interactive Computer-Assisted Instruction in Acid-Base Physiology for Mobile Computer Platforms

Science.gov (United States)

Longmuir, Kenneth J.

2014-01-01

In this project, the traditional lecture hall presentation of acid-base physiology in the first-year medical school curriculum was replaced by interactive, computer-assisted instruction designed primarily for the iPad and other mobile computer platforms. Three learning modules were developed, each with ~20 screens of information, on the subjects…

Intrinsic Electron Mobility Limits in beta-Ga2O3

OpenAIRE

Ma, Nan; Tanen, Nicholas; Verma, Amit; Guo, Zhi; Luo, Tengfei; Huili; Xing; Jena, Debdeep

2016-01-01

By systematically comparing experimental and theoretical transport properties, we identify the polar optical phonon scattering as the dominant mechanism limiting electron mobility in beta-Ga2O3 to lower than 200 cm2/Vs at 300 K for donor doping densities lower than 1018 cm-3. In spite of similar electron effective mass of beta-Ga2O3 to GaN, the electron mobility is 10x lower because of a massive Frohlich interaction, due to the low phonon energies stemming from the crystal structure and stron...

Application-oriented offloading in heterogeneous networks for mobile cloud computing

Science.gov (United States)

Tseng, Fan-Hsun; Cho, Hsin-Hung; Chang, Kai-Di; Li, Jheng-Cong; Shih, Timothy K.

2018-04-01

Nowadays Internet applications have become more complicated that mobile device needs more computing resources for shorter execution time but it is restricted to limited battery capacity. Mobile cloud computing (MCC) is emerged to tackle the finite resource problem of mobile device. MCC offloads the tasks and jobs of mobile devices to cloud and fog environments by using offloading scheme. It is vital to MCC that which task should be offloaded and how to offload efficiently. In the paper, we formulate the offloading problem between mobile device and cloud data center and propose two algorithms based on application-oriented for minimum execution time, i.e. the Minimum Offloading Time for Mobile device (MOTM) algorithm and the Minimum Execution Time for Cloud data center (METC) algorithm. The MOTM algorithm minimizes offloading time by selecting appropriate offloading links based on application categories. The METC algorithm minimizes execution time in cloud data center by selecting virtual and physical machines with corresponding resource requirements of applications. Simulation results show that the proposed mechanism not only minimizes total execution time for mobile devices but also decreases their energy consumption.

Trends in Mobile Computing: State-of-the-Art and Next Steps

CERN Document Server

CERN. Geneva

2006-01-01

Computing is moving to the edge of the network. It is becoming increasingly personal and allowing people to enjoy and express themselves in unprecedented ways. The same development allows professionals and enterprises to increase quality and productivity through improved mobility. The seminar discusses the underlying technical and societal trends and the state-of-the-art of mobile computing. Examples of current developments include the transformation of mobile devices into servers, augmented reality in mobile devices and the opportunities offered by wireless sensor networks. The fusion of the physical and digital worlds enabled by mobile computing is driving industry and society to adopt new uses of digital technologies and causing the focus of development to shift from hardware products to new services. Bio:Since 2004 Prof. Jan Bosch is working as Vice President and Head of the Software and Application Technology Laboratory of Nokia Research Centre in Helsinki, Finland. The Software & Application Tec...

The Future of the Mobile Payment as Electronic Payment System

OpenAIRE

Bezovski, Zlatko

2016-01-01

The development of the Internet and the arrival of e-commerce fostered digitalization in the payment processes by providing a variety of electronic payment options including payment cards (credit and debit), digital and mobile wallets, electronic cash, contactless payment methods etc. Mobile payment services with their increasing popularity are presently under the phase of transition, heading towards a promising future of tentative possibilities along with the innovation in technology. In thi...

ISSUES IN MOBILE DISTRIBUTED REAL TIME DATABASES: PERFORMANCE AND REVIEW

OpenAIRE

VISHNU SWAROOP,; Gyanendra Kumar Gupta,; UDAI SHANKER

2011-01-01

Increase in handy and small electronic devices in computing fields; it makes the computing more popularand useful in business. Tremendous advances in wireless networks and portable computing devices have led to development of mobile computing. Support of real time database system depending upon thetiming constraints, due to availability of data distributed database, and ubiquitous computing pull the mobile database concept, which emerges them in a new form of technology as mobile distributed ...

Electron mobility of two-dimensional electron gas in InGaN heterostructures: Effects of alloy disorder and random dipole scatterings

Science.gov (United States)

Hoshino, Tomoki; Mori, Nobuya

2018-04-01

InGaN has a smaller electron effective mass and is expected to be used as a channel material for high-electron-mobility transistors. However, it is an alloy semiconductor with a random distribution of atoms, which introduces additional scattering mechanisms: alloy disorder and random dipole scatterings. In this work, we calculate the electron mobility in InGaN- and GaN-channel high-electron-mobility transistors (HEMTs) while taking into account acoustic deformation potential, polar optical phonon, alloy disorder, and random dipole scatterings. For InGaN-channel HEMTs, we find that not only alloy disorder but also random dipole scattering has a strong impact on the electron mobility and it significantly decreases as the In mole fraction of the channel increases. Our calculation also shows that the channel thickness w dependence of the mobility is rather weak when w > 1 nm for In0.1Ga0.9N-channel HEMTs.

78 FR 23593 - Certain Mobile Electronic Devices Incorporating Haptics; Termination of Investigation

Science.gov (United States)

2013-04-19

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-834] Certain Mobile Electronic Devices... the importation, sale for importation, and sale within the United States after importation of certain mobile electronic devices incorporating haptics that infringe certain claims of six Immersion patents. 77...

Development of mobile electron beam plant for environmental applications

International Nuclear Information System (INIS)

Han, Bumsoo; Kim, Jinkyu; Kang, Wongu; Choi, Jang Seung; Jeong, Kwang-Young

2016-01-01

Due to the necessity of pilot scale test facility for continuous treatment of wastewater and gases on site, a mobile electron beam irradiation system mounted on a trailer has developed. This mobile electron beam irradiation system is designed for the individual field application with self-shielded structure of steel plate and lead block which will satisfy the required safety figures of International Commission on Radiological Protection (ICRP). Shielding of a mobile electron accelerator of 0.7 MeV, 30 mA has been designed and examined by Monte Carlo technique. Based on a 3-D model of electron accelerator shielding which is designed with steel and lead shield, radiation leakage was examined using the Monte Carlo N-Particle Transport (MCNP) Code. Simulations with two different versions (version 4c2 and version 5) of MCNP code showed agreements within statistical uncertainties, and the highest leakage expected is 5.5061×10 −01 (1±0.0454) μSv/h, which is far below the tolerable radiation dose limit for occupational workers. This unit could treat up to 500 m 3 of liquid waste per day at 2 kGy or 10,000 N m 3 of gases per hour at 15 kGy. - Highlights: • A mobile electron beam irradiation system mounted on a trailer has developed. • It is designed for treatment of wastewater and flue gas on site. • Shielding of 0.7 MeV, 30 mA accelerator has done by a Monte Carlo technique. • It can treat up to 500 m 3 /d of liquid waste at 2 kGy or 10,000 N m 3 /h of gas at 15 kGy.

Mobile Learning According to Students of Computer Engineering and Computer Education: A Comparison of Attitudes

Directory of Open Access Journals (Sweden)

Deniz Mertkan GEZGIN

2018-01-01

Full Text Available Mobile learning has started to perform an increasingly significant role in improving learning outcomes in education. Successful and efficient implementation of m-learning in higher education, as with all educational levels, depends on users’ acceptance of this technology. This study focuses on investigating the attitudes of undergraduate students of Computer Engineering (CENG and Computer Education and Instructional Technology (CEIT departments in a Turkish public university towards m-learning from three perspectives; gender, area of study, and mobile device ownership. Using a correlational survey method, a Mobile Learning Attitude Scale (MLAS was administered to 531 students, analysis of which revealed a positive attitude to m-learning in general. A further investigation of the aforementioned three variables showed a more positive attitude for female students in terms of usability, for CEIT students in terms of advantages, usability and independence, and for those owning a mobile device in terms of usability. An important implication from the findings, among others, is supplementing Computer Engineering curriculum with elective courses on the fundamentals of mobile learning, and/or the design and development of m-learning software, so as to create, in the long run, more specialized and complementary teams comprised of trained CENG and CEIT graduates in m-learning sector.

Computer modeling of ORNL storage tank sludge mobilization and mixing

International Nuclear Information System (INIS)

Terrones, G.; Eyler, L.L.

1993-09-01

This report presents and analyzes the results of the computer modeling of mixing and mobilization of sludge in horizontal, cylindrical storage tanks using submerged liquid jets. The computer modeling uses the TEMPEST computational fluid dynamics computer program. The horizontal, cylindrical storage tank configuration is similar to the Melton Valley Storage Tanks (MVST) at Oak Ridge National (ORNL). The MVST tank contents exhibit non-homogeneous, non-Newtonian rheology characteristics. The eventual goals of the simulations are to determine under what conditions sludge mobilization using submerged liquid jets is feasible in tanks of this configuration, and to estimate mixing times required to approach homogeneity of the contents of the tanks

Correlation Between Two-Dimensional Electron Gas Mobility and Crystal Quality in AlGaN/GaN High-Electron-Mobility Transistor Structure Grown on 4H-SiC.

Science.gov (United States)

Heo, Cheon; Jang, Jongjin; Lee, Kyngjae; So, Byungchan; Lee, Kyungbae; Ko, Kwangse; Nam, Okhyun

2017-01-01

We investigated the correlation between the crystal quality and two-dimensional electron gas (2DEG) mobility of an AlGaN/GaN high-electron-mobility transistor (HEMT) structure grown by metal-organic chemical vapor deposition. For the structure with an AlN nucleation layer grown at 1100 °C, the 2DEG mobility and sheet carrier density were 1627 cm²/V·s and 3.23 × 10¹³ cm⁻², respectively, at room temperature. Further, it was confirmed that the edge dislocation density of the GaN buffer layer was related to the 2DEG mobility and sheet carrier density in the AlGaN/GaN HEMT.

Framework for emotional mobile computation for creating entertainment experience

Science.gov (United States)

Lugmayr, Artur R.

2007-02-01

Ambient media are media, which are manifesting in the natural environment of the consumer. The perceivable borders between the media and the context, where the media is used are getting more and more blurred. The consumer is moving through a digital space of services throughout his daily life. As we are developing towards an experience society, the central point in the development of services is the creation of a consumer experience. This paper reviews possibilities and potentials of the creation of entertainment experiences with mobile phone platforms. It reviews sensor network capable of acquiring consumer behavior data, interactivity strategies, psychological models for emotional computation on mobile phones, and lays the foundations of a nomadic experience society. The paper rounds up with a presentation of several different possible service scenarios in the field of entertainment and leisure computation on mobiles. The goal of this paper is to present a framework and evaluation of possibilities of applying sensor technology on mobile platforms to create an increasing consumer entertainment experience.

Security and Trust in Mobile Cloud Computing

OpenAIRE

Le Vinh , Thinh

2017-01-01

As living in the cyber era, we admit that a dozen of new technologies have been born every day with the promises that making a human life be more comfortable, convenient and safe. In the forest of new technologies, mobile computing is raise as an essential part of human life. Normally, mobile devices have become the best companions in daily activities. They have served us from the simple activities like entertainment to the complicated one as business operations. As playing the important role...

Psychiatrists' Comfort Using Computers and Other Electronic Devices in Clinical Practice.

Science.gov (United States)

Duffy, Farifteh F; Fochtmann, Laura J; Clarke, Diana E; Barber, Keila; Hong, Seung-Hee; Yager, Joel; Mościcki, Eve K; Plovnick, Robert M

2016-09-01

This report highlights findings from the Study of Psychiatrists' Use of Informational Resources in Clinical Practice, a cross-sectional Web- and paper-based survey that examined psychiatrists' comfort using computers and other electronic devices in clinical practice. One-thousand psychiatrists were randomly selected from the American Medical Association Physician Masterfile and asked to complete the survey between May and August, 2012. A total of 152 eligible psychiatrists completed the questionnaire (response rate 22.2 %). The majority of psychiatrists reported comfort using computers for educational and personal purposes. However, 26 % of psychiatrists reported not using or not being comfortable using computers for clinical functions. Psychiatrists under age 50 were more likely to report comfort using computers for all purposes than their older counterparts. Clinical tasks for which computers were reportedly used comfortably, specifically by psychiatrists younger than 50, included documenting clinical encounters, prescribing, ordering laboratory tests, accessing read-only patient information (e.g., test results), conducting internet searches for general clinical information, accessing online patient educational materials, and communicating with patients or other clinicians. Psychiatrists generally reported comfort using computers for personal and educational purposes. However, use of computers in clinical care was less common, particularly among psychiatrists 50 and older. Information and educational resources need to be available in a variety of accessible, user-friendly, computer and non-computer-based formats, to support use across all ages. Moreover, ongoing training and technical assistance with use of electronic and mobile device technologies in clinical practice is needed. Research on barriers to clinical use of computers is warranted.

Psychiatrists’ Comfort Using Computers and Other Electronic Devices in Clinical Practice

Science.gov (United States)

Fochtmann, Laura J.; Clarke, Diana E.; Barber, Keila; Hong, Seung-Hee; Yager, Joel; Mościcki, Eve K.; Plovnick, Robert M.

2015-01-01

This report highlights findings from the Study of Psychiatrists’ Use of Informational Resources in Clinical Practice, a cross-sectional Web- and paper-based survey that examined psychiatrists’ comfort using computers and other electronic devices in clinical practice. One-thousand psychiatrists were randomly selected from the American Medical Association Physician Masterfile and asked to complete the survey between May and August, 2012. A total of 152 eligible psychiatrists completed the questionnaire (response rate 22.2 %). The majority of psychiatrists reported comfort using computers for educational and personal purposes. However, 26 % of psychiatrists reported not using or not being comfortable using computers for clinical functions. Psychiatrists under age 50 were more likely to report comfort using computers for all purposes than their older counterparts. Clinical tasks for which computers were reportedly used comfortably, specifically by psychiatrists younger than 50, included documenting clinical encounters, prescribing, ordering laboratory tests, accessing read-only patient information (e.g., test results), conducting internet searches for general clinical information, accessing online patient educational materials, and communicating with patients or other clinicians. Psychiatrists generally reported comfort using computers for personal and educational purposes. However, use of computers in clinical care was less common, particularly among psychiatrists 50 and older. Information and educational resources need to be available in a variety of accessible, user-friendly, computer and non-computer-based formats, to support use across all ages. Moreover, ongoing training and technical assistance with use of electronic and mobile device technologies in clinical practice is needed. Research on barriers to clinical use of computers is warranted. PMID:26667248

Mobilities of slow electrons in low- and high-pressure gases and liquids

International Nuclear Information System (INIS)

Christophorou, L.G.

1975-01-01

Mobilities of slow (thermal and epithermal) electrons in low- (less than or approximately 500 Torr) and high- (approximately 500 to approximately 34,111 Torr) pressure gases are discussed and are related to the molecular structure and to the mobilities of thermal electrons in liquid media

Fundamental limits on the electron mobility of β-Ga2O3.

Science.gov (United States)

Kang, Youngho; Krishnaswamy, Karthik; Peelaers, Hartwin; Van de Walle, Chris G

2017-06-14

We perform first-principles calculations to investigate the electronic and vibrational spectra and the electron mobility of β-Ga 2 O 3 . We calculate the electron-phonon scattering rate of the polar optical phonon modes using the Vogl model in conjunction with Fermi's golden rule; this enables us to fully take the anisotropic phonon spectra of the monoclinic lattice of β-Ga 2 O 3 into account. We also examine the scattering rate due to ionized impurities or defects using a Yukawa-potential-based model. We consider scattering due to donor impurities, as well as the possibility of compensation by acceptors such as Ga vacancies. We then calculate the room-temperature mobility of β-Ga 2 O 3 using the Boltzmann transport equation within the relaxation time approximation, for carrier densities in the range from 10 17 to 10 20 cm -3 . We find that the electron-phonon interaction dominates the mobility for carrier densities of up to 10 19 cm -3 . We also find that the intrinsic anisotropy in the mobility is small; experimental findings of large anisotropy must therefore be attributed to other factors. We attribute the experimentally observed reduction of the mobility with increasing carrier density to increasing levels of compensation, which significantly affect the mobility.

Fundamental limits on the electron mobility of β-Ga2O3

Science.gov (United States)

Kang, Youngho; Krishnaswamy, Karthik; Peelaers, Hartwin; Van de Walle, Chris G.

2017-06-01

We perform first-principles calculations to investigate the electronic and vibrational spectra and the electron mobility of β-Ga2O3. We calculate the electron-phonon scattering rate of the polar optical phonon modes using the Vogl model in conjunction with Fermi’s golden rule; this enables us to fully take the anisotropic phonon spectra of the monoclinic lattice of β-Ga2O3 into account. We also examine the scattering rate due to ionized impurities or defects using a Yukawa-potential-based model. We consider scattering due to donor impurities, as well as the possibility of compensation by acceptors such as Ga vacancies. We then calculate the room-temperature mobility of β-Ga2O3 using the Boltzmann transport equation within the relaxation time approximation, for carrier densities in the range from 1017 to 1020 cm-3. We find that the electron-phonon interaction dominates the mobility for carrier densities of up to 1019 cm-3. We also find that the intrinsic anisotropy in the mobility is small; experimental findings of large anisotropy must therefore be attributed to other factors. We attribute the experimentally observed reduction of the mobility with increasing carrier density to increasing levels of compensation, which significantly affect the mobility.

Individual Tariffs for Mobile Services: Theoretical Framework and a Computational Case in Mobile Music

OpenAIRE

Chen, Hong; Pau, Louis-François

2007-01-01

textabstractThis paper introduces individual tariffs at service and content bundle level in mobile communications. It gives a theoretical framework (economic, sociological) as well as a computational game solution method. The user can be an individual or a community. Individual tariffs are decided through interactions between the user and the supplier. A numerical example from mobile music illustrates the concepts.

Electron drift time in silicon drift detectors: A technique for high precision measurement of electron drift mobility

International Nuclear Information System (INIS)

Castoldi, A.; Rehak, P.

1995-01-01

This paper presents a precise absolute measurement of the drift velocity and mobility of electrons in high resistivity silicon at room temperature. The electron velocity is obtained from the differential measurement of the drift time of an electron cloud in a silicon drift detector. The main features of the transport scheme of this class of detectors are: the high uniformity of the electron motion, the transport of the signal electrons entirely contained in the high-purity bulk, the low noise timing due to the very small anode capacitance (typical value 100 fF), and the possibility to measure different drift distances, up to the wafer diameter, in the same semiconductor sample. These features make the silicon drift detector an optimal device for high precision measurements of carrier drift properties. The electron drift velocity and mobility in a 10 kΩ cm NTD n-type silicon wafer have been measured as a function of the electric field in the range of possible operation of a typical drift detector (167--633 V/cm). The electron ohmic mobility is found to be 1394 cm 2 /V s. The measurement precision is better than 1%. copyright 1995 American Institute of Physics

Adaptive security protocol selection for mobile computing

NARCIS (Netherlands)

Pontes Soares Rocha, B.; Costa, D.N.O.; Moreira, R.A.; Rezende, C.G.; Loureiro, A.A.F.; Boukerche, A.

2010-01-01

The mobile computing paradigm has introduced new problems for application developers. Challenges include heterogeneity of hardware, software, and communication protocols, variability of resource limitations and varying wireless channel quality. In this scenario, security becomes a major concern for

Mobile interstitial model and mobile electron model of mechano-induced luminescence in coloured alkali halide crystals

International Nuclear Information System (INIS)

Chandra, B.P.; Singh, Seema; Ojha, Bharti; Shrivastava, R.G.

1996-01-01

A theoretical study is made on the mobile interstitial and mobile electron models of mechano-induced luminescence in coloured alkali halide crystals. Equations derived indicate that the mechanoluminescence intensity should depend on several factors like strain rate, applied stress, temperature, density of F-centres and volume of crystal. The equations also involve the efficiency and decay time of mechanoluminescence. Results of mobile interstitial and mobile electron models are compared with the experimental observations, which indicated that the latter is more suitable as compared to the former. From the temperature dependence of ML, the energy gaps between the dislocation band and ground state of F-centre is calculated which are 0.08, 0.072 and 0.09 eV for KCl, KBr and NaCl crystals, respectively. The theory predicts that the decay of ML intensity is related to the process of stress relaxation in crystals. (author). 33 refs., 5 figs., 1 tab

Excess electron mobility in ethane. Density, temperature, and electric field effects

International Nuclear Information System (INIS)

Doeldissen, W.; Schmidt, W.F.; Bakale, G.

1980-01-01

The excess electron mobility in liquid ethane was measured under orthobaric conditions as a function of temperature and electric field strength up to the critical temperature at 305.33 K. The low field mobility was found to rise strongly with temperature and exhibits a maximum value of 44 cm 2 V -1 s -1 at 2 0 below the critical temperature. At temperatures above 260 K the electron drift velocity shows a sublinear field dependence at high values of the electric field strength. These observations lead to the supposition that in liquid ethane a transition from transport via localized states to transport in extended states occurs. Measurements were also performed in fluid ethane at densities from 2.4 to 12.45 mol L -1 and temperatures from 290 to 340 K. On isochores in the vicinity of the critical density, an increase of the low field mobility with temperature was observed. This effect was found to disappear both at low (rho = 2.4 mol L -1 ) and high densities (rho greater than or equal to 9.2 mol L -1 ). In this density range, a sublinear field dependence of the drift velocities at high field strengths was noted. The critical velocity associated with the appearance of hot electrons was observed to decrease with higher densities indicating a smaller fractional energy transfer in electron molecule collisions. A compilation of electron mobilities in gaseous and liquid ethane shows that, up to densitiesof rho = 9.5 mol L -1 , μ proportional to n -1 is fulfilled if temperature effects are ignored. At intermediate densities, 9 mol L -1 -1 , a density dependence of μ proportional to rho -5 is found followed by a stronger mobility decrease toward the triple point. Positive ion mobilities measured under orthobaric conditions followed Walden's rule

Lead Halide Perovskites as Charge Generation Layers for Electron Mobility Measurement in Organic Semiconductors.

Science.gov (United States)

Love, John A; Feuerstein, Markus; Wolff, Christian M; Facchetti, Antonio; Neher, Dieter

2017-12-06

Hybrid lead halide perovskites are introduced as charge generation layers (CGLs) for the accurate determination of electron mobilities in thin organic semiconductors. Such hybrid perovskites have become a widely studied photovoltaic material in their own right, for their high efficiencies, ease of processing from solution, strong absorption, and efficient photogeneration of charge. Time-of-flight (ToF) measurements on bilayer samples consisting of the perovskite CGL and an organic semiconductor layer of different thickness are shown to be determined by the carrier motion through the organic material, consistent with the much higher charge carrier mobility in the perovskite. Together with the efficient photon-to-electron conversion in the perovskite, this high mobility imbalance enables electron-only mobility measurement on relatively thin application-relevant organic films, which would not be possible with traditional ToF measurements. This architecture enables electron-selective mobility measurements in single components as well as bulk-heterojunction films as demonstrated in the prototypical polymer/fullerene blends. To further demonstrate the potential of this approach, electron mobilities were measured as a function of electric field and temperature in an only 127 nm thick layer of a prototypical electron-transporting perylene diimide-based polymer, and found to be consistent with an exponential trap distribution of ca. 60 meV. Our study furthermore highlights the importance of high mobility charge transporting layers when designing perovskite solar cells.

Electron-capture process and ion mobility spectra in plasma chromatography

International Nuclear Information System (INIS)

Karasek, F.W.; Spangler, G.E.

1981-01-01

The basic principles of plasma chromatography are introduced and ion mobility relationships presented. The relationships of plasma chromatography to electron-capture detector mechanisms are discussed, including electron energy considerations and electron-capture reactions. A number of experimental studies by plasma chromatography are described. (C.F.)

78 FR 34132 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

Science.gov (United States)

2013-06-06

... INTERNATIONAL TRADE COMMISSION [Docket No 2958] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Correction to Notice of Receipt of Complaint; Solicitation... of complaint entitled Certain Portable Electronic Communications Devices, Including Mobile Phones and...

Optimal Computing Resource Management Based on Utility Maximization in Mobile Crowdsourcing

Directory of Open Access Journals (Sweden)

Haoyu Meng

2017-01-01

Full Text Available Mobile crowdsourcing, as an emerging service paradigm, enables the computing resource requestor (CRR to outsource computation tasks to each computing resource provider (CRP. Considering the importance of pricing as an essential incentive to coordinate the real-time interaction among the CRR and CRPs, in this paper, we propose an optimal real-time pricing strategy for computing resource management in mobile crowdsourcing. Firstly, we analytically model the CRR and CRPs behaviors in form of carefully selected utility and cost functions, based on concepts from microeconomics. Secondly, we propose a distributed algorithm through the exchange of control messages, which contain the information of computing resource demand/supply and real-time prices. We show that there exist real-time prices that can align individual optimality with systematic optimality. Finally, we also take account of the interaction among CRPs and formulate the computing resource management as a game with Nash equilibrium achievable via best response. Simulation results demonstrate that the proposed distributed algorithm can potentially benefit both the CRR and CRPs. The coordinator in mobile crowdsourcing can thus use the optimal real-time pricing strategy to manage computing resources towards the benefit of the overall system.

77 FR 15390 - Certain Mobile Electronic Devices Incorporating Haptics; Receipt of Amended Complaint...

Science.gov (United States)

2012-03-15

... INTERNATIONAL TRADE COMMISSION [DN 2875] Certain Mobile Electronic Devices Incorporating Haptics.... International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received an amended complaint entitled Certain Mobile Electronic Devices...

Charge carrier mobility and electronic properties of Al(Op3: impact of excimer formation

Directory of Open Access Journals (Sweden)

Andrea Magri

2015-05-01

Full Text Available We have studied the electronic properties and the charge carrier mobility of the organic semiconductor tris(1-oxo-1H-phenalen-9-olatealuminium(III (Al(Op3 both experimentally and theoretically. We experimentally estimated the HOMO and LUMO energy levels to be −5.93 and −3.26 eV, respectively, which were close to the corresponding calculated values. Al(Op3 was successfully evaporated onto quartz substrates and was clearly identified in the absorption spectra of both the solution and the thin film. A structured steady state fluorescence emission was detected in solution, whereas a broad, red-shifted emission was observed in the thin film. This indicates the formation of excimers in the solid state, which is crucial for the transport properties. The incorporation of Al(Op3 into organic thin film transistors (TFTs was performed in order to measure the charge carrier mobility. The experimental setup detected no electron mobility, while a hole mobility between 0.6 × 10−6 and 2.1 × 10−6 cm2·V−1·s−1 was measured. Theoretical simulations, on the other hand, predicted an electron mobility of 9.5 × 10−6 cm2·V−1·s−1 and a hole mobility of 1.4 × 10−4 cm2·V−1·s−1. The theoretical simulation for the hole mobility predicted an approximately one order of magnitude higher hole mobility than was observed in the experiment, which is considered to be in good agreement. The result for the electron mobility was, on the other hand, unexpected, as both the calculated electron mobility and chemical common sense (based on the capability of extended aromatic structures to efficiently accept and delocalize additional electrons suggest more robust electron charge transport properties. This discrepancy is explained by the excimer formation, whose inclusion in the multiscale simulation workflow is expected to bring the theoretical simulation and experiment into agreement.

Principles of mobile computing and communications

CERN Document Server

Othman, Mazliza

2007-01-01

Introduction Mobile Computing Applications Evolution of Wireless Networks and Services Summary Cellular Network Architecture UMTS Architecture Public Land Mobile Network Interfaces User Authentication Frequency Reuse Channel Assignment Location Registration and Update Handover Procedures CDMA The Move toward 3G Networks Wireless Local Area Networks IEEE 802.11 Standard IEEE 802.11b Standard (Wi-Fi) IEEE 802.11a Standard IEEE 802.11g Standard HIPERLAN/2 IEEE 802.1x Standard IEEE 802.11i Standard IEEE 802.11e Standard Security Issues IP over 802.11 WLAN Integrating 802.11 WLAN and UMTS Summary Wireless Personal Area Networks HomeRF Bluetooth Technology IEEE 802.15.3 Standard Home Area Networks Summary Wireless Sensor Networks Applications of WSNs Requirements for WSNs WSN Architecture The 802.15.4 Standard The ZigBee Protocol Power Conservation Techniques Network and Communications Configuration of Sensor Networks WSN and Emergency Response Applications Summary Mobile Ad Hoc Networks AODV DSR OLSR TBRPF Summary...

Mobile Cloud-Computing-Based Healthcare Service by Noncontact ECG Monitoring

Directory of Open Access Journals (Sweden)

Ee-May Fong

2013-12-01

Full Text Available Noncontact electrocardiogram (ECG measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service.

Location-Based Services and Privacy Protection Under Mobile Cloud Computing

OpenAIRE

Yan, Yan; Xiaohong, Hao; Wanjun, Wang

2015-01-01

Location-based services can provide personalized services based on location information of moving objects and have already been widely used in public safety services, transportation, entertainment and many other areas. With the rapid development of mobile communication technology and popularization of intelligent terminals, there will be great commercial prospects to provide location-based services under mobile cloud computing environment. However, the high adhesion degree of mobile terminals...

UrbanWeb: a Platform for Mobile Context-aware Social Computing

DEFF Research Database (Denmark)

Hansen, Frank Allan; Grønbæk, Kaj

2010-01-01

UrbanWeb is a novel Web-based context-aware hypermedia plat- form. It provides essential mechanisms for mobile social comput- ing applications: the framework implements context as an exten- sion to Web 2.0 tagging and provides developers with an easy to use platform for mobile context......-aware applications. Services can be statically or dynamically defined in the user’s context, data can be pre-cached for data intensive mobile applications, and shared state supports synchronization between running applications such as games. The paper discusses how UrbanWeb acquires cues about the user’s context...... from sensors in mobile phones, ranging from GPS data, to 2D barcodes, and manual entry of context in- formation, as well as how to utilize this context in applications. The experiences show that the UrbanWeb platform efficiently supports a rich variety of urban computing applications in differ- ent...

Use of Computer and Mobile Technologies in the Treatment of Depression.

Science.gov (United States)

Callan, Judith A; Wright, Jesse; Siegle, Greg J; Howland, Robert H; Kepler, Britney B

2017-06-01

Major depression (MDD) is a common and disabling disorder. Research has shown that most people with MDD receive either no treatment or inadequate treatment. Computer and mobile technologies may offer solutions for the delivery of therapies to untreated or inadequately treated individuals with MDD. The authors review currently available technologies and research aimed at relieving symptoms of MDD. These technologies include computer-assisted cognitive-behavior therapy (CCBT), web-based self-help, Internet self-help support groups, mobile psychotherapeutic interventions (i.e., mobile applications or apps), technology enhanced exercise, and biosensing technology. Copyright © 2017 Elsevier Inc. All rights reserved.

A study of the advantages & disadvantages of mobile cloud computing versus native environment

OpenAIRE

Almrot, Emil; Andersson, Sebastian

2013-01-01

The advent of cloud computing has enabled the possibility of moving complex calculations and device operations to the “cloud” in an effective way. With cloud computing being applied to mobile devices some of the primary constraints of mobile computing, such as battery life and hardware with less computational power, could be resolved by moving complex operations and computations to the cloud. This thesis aims to identify advantages and disadvantages associated with running cloud based applica...

Mobile Computing and Cloud maturity - Introducing Machine Learning for ERP Configuration Automation

Directory of Open Access Journals (Sweden)

Elena Geanina ULARU

2013-01-01

Full Text Available Nowadays the smart phone market is clearly growing due to the new type of functionalities that mobile devices have and the role that they play in everyday life. Their utility and benefits rely on the applications that can be installed on the device (the so-called mobile apps. Cloud computing is a way to enhance the world of mobile application by providing disk space and freeing the user of the local storage needs, this way providing cheaper storage, wider acces-sibility and greater speed for business. In this paper we introduce various aspects of mobile computing and we stress the importance of obtaining cloud maturity by using machine learning for automating configurations of software applications deployed on cloud nodes using the open source application ERP5 and SlapOS, an open source operating system for Decentralized Cloud Computing.

The Design of a System Architecture for Mobile Multimedia Computers

NARCIS (Netherlands)

Havinga, Paul J.M.

2000-01-01

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile

Electron mobility in few-layer MoxW1-xS2

International Nuclear Information System (INIS)

Chandrasekar, Hareesh; Nath, Digbijoy N

2015-01-01

Heterostructures of two-dimensional (2D) layered materials are increasingly being explored for electronics in order to potentially extend conventional transistor scaling and to exploit new device designs and architectures. Alloys form a key underpinning of any heterostructure device technology and therefore an understanding of their electronic properties is essential. In this paper, we study the intrinsic electron mobility in few-layer Mo x W 1−x S 2 as limited by various scattering mechanisms. The room temperature, energy-dependent scattering times corresponding to polar longitudinal optical (LO) phonon, alloy and background impurity scattering mechanisms are estimated based on the Born approximation to Fermi’s golden rule. The contribution of individual scattering rates is analyzed as a function of 2D electron density as well as of alloy composition in Mo x W 1−x S 2 . While impurity scattering limits the mobility for low carrier densities (<2–4×10 12 cm −2 ), LO polar phonon scattering is the dominant mechanism for high electron densities. Alloy scattering is found to play a non-negligible role for 0.5 < x < 0.7 in Mo x W 1−x S 2 . The LO phonon-limited and impurity-limited mobilities show opposing trends with respect to alloy mole fractions. The understanding of electron mobility in Mo x W 1−x S 2 presented here is expected to enable the design and realization of heterostructures and devices based on alloys of MoS 2 and WS 2 . (paper)

Mobile Computing Changing the Traditional Ways of Organizing the Construction Company

OpenAIRE

Nataa uman; Mirko Punder

2008-01-01

The focus of this paper is to represent some important mobile computing potential which help tackle project collaboration and information dissemination problems. Especially in the construction industry where workers have no steady working places mobile computing is shown as a chance for optimising the traditional ways of organizing Construction Company. Special attention is given to the description of changing the current information system as well as to the hierarchical organization structur...

Introduction to electronic analogue computers

CERN Document Server

Wass, C A A

1965-01-01

Introduction to Electronic Analogue Computers, Second Revised Edition is based on the ideas and experience of a group of workers at the Royal Aircraft Establishment, Farnborough, Hants. This edition is almost entirely the work of Mr. K. C. Garner, of the College of Aeronautics, Cranfield. As various advances have been made in the technology involving electronic analogue computers, this book presents discussions on the said progress, including some acquaintance with the capabilities of electronic circuits and equipment. This text also provides a mathematical background including simple differen

Patterning of high mobility electron gases at complex oxide interfaces

DEFF Research Database (Denmark)

Trier, Felix; Prawiroatmodjo, G. E. D. K.; von Soosten, Merlin

2015-01-01

Oxide interfaces provide an opportunity for electronics. However, patterning of electron gases at complex oxide interfaces is challenging. In particular, patterning of complex oxides while preserving a high electron mobility remains underexplored and inhibits the study of quantum mechanical effects...... of amorphous-LSM (a-LSM) thin films, which acts as a hard mask during subsequent depositions. Strikingly, the patterned modulation-doped interface shows electron mobilities up to ∼8 700 cm2/V s at 2 K, which is among the highest reported values for patterned conducting complex oxide interfaces that usually...... where extended electron mean free paths are paramount. This letter presents an effective patterning strategy of both the amorphous-LaAlO3/SrTiO3 (a-LAO/STO) and modulation-doped amorphous-LaAlO3/La7/8Sr1/8MnO3/SrTiO3 (a-LAO/LSM/STO) oxide interfaces. Our patterning is based on selective wet etching...

High electron mobility and large magnetoresistance in the half-Heusler semimetal LuPtBi

KAUST Repository

Hou, Zhipeng

2015-12-18

Materials with high carrier mobility showing large magnetoresistance (MR) have recently received much attention because of potential applications in future high-performance magnetoelectric devices. Here, we report on an electron-hole-compensated half-Heusler semimetal LuPtBi that exhibits an extremely high electron mobility of up to 79000cm2/Vs with a nonsaturating positive MR as large as 3200% at 2 K. Remarkably, the mobility at 300 K is found to exceed 10500cm2/Vs, which is among the highest values reported in three-dimensional bulk materials thus far. The clean Shubnikov–de Haas quantum oscillation observed at low temperatures and the first-principles calculations together indicate that the high electron mobility is due to a rather small effective carrier mass caused by the distinctive band structure of the crystal. Our findings provide a different approach for finding large, high-mobility MR materials by designing an appropriate Fermi surface topology starting from simple electron-hole-compensated semimetals.

Distributed Factorization Computation on Multiple Volunteered Mobile Resource to Break RSA Key

Science.gov (United States)

Jaya, I.; Hardi, S. M.; Tarigan, J. T.; Zamzami, E. M.; Sihombing, P.

2017-01-01

Similar to common asymmeric encryption, RSA can be cracked by usmg a series mathematical calculation. The private key used to decrypt the massage can be computed using the public key. However, finding the private key may require a massive amount of calculation. In this paper, we propose a method to perform a distributed computing to calculate RSA’s private key. The proposed method uses multiple volunteered mobile devices to contribute during the calculation process. Our objective is to demonstrate how the use of volunteered computing on mobile devices may be a feasible option to reduce the time required to break a weak RSA encryption and observe the behavior and running time of the application on mobile devices.

Embodied Computation: An Active-Learning Approach to Mobile Robotics Education

Science.gov (United States)

Riek, L. D.

2013-01-01

This paper describes a newly designed upper-level undergraduate and graduate course, Autonomous Mobile Robots. The course employs active, cooperative, problem-based learning and is grounded in the fundamental computational problems in mobile robotics defined by Dudek and Jenkin. Students receive a broad survey of robotics through lectures, weekly…

Promises and Pitfalls of Computer-Supported Mindfulness: Exploring a Situated Mobile Approach

Directory of Open Access Journals (Sweden)

Ralph Vacca

2017-12-01

Full Text Available Computer-supported mindfulness (CSM is a burgeoning area filled with varied approaches such as mobile apps and EEG headbands. However, many of the approaches focus on providing meditation guidance. The ubiquity of mobile devices may provide new opportunities to support mindfulness practices that are more situated in everyday life. In this paper, a new situated mindfulness approach is explored through a specific mobile app design. Through an experimental design, the approach is compared to traditional audio-based mindfulness meditation, and a mind wandering control, over a one-week period. The study demonstrates the viability for a situated mobile mindfulness approach to induce mindfulness states. However, phenomenological aspects of the situated mobile approach suggest both promises and pitfalls for computer-supported mindfulness using a situated approach.

Mobile computing in critical care.

Science.gov (United States)

Lapinsky, Stephen E

2007-03-01

Handheld computing devices are increasingly used by health care workers, and offer a mobile platform for point-of-care information access. Improved technology, with larger memory capacity, higher screen resolution, faster processors, and wireless connectivity has broadened the potential roles for these devices in critical care. In addition to the personal information management functions, handheld computers have been used to access reference information, management guidelines and pharmacopoeias as well as to track the educational experience of trainees. They can act as an interface with a clinical information system, providing rapid access to patient information. Despite their popularity, these devices have limitations related to their small size, and acceptance by physicians has not been uniform. In the critical care environment, the risk of transmitting microorganisms by such a portable device should always be considered.

Mobile computation offloading architecture for mobile augmented reality, case study: Visualization of cetacean skeleton

OpenAIRE

Belen G. Rodriguez-Santana; Amilcar Meneses Viveros; Blanca Esther Carvajal-Gamez; Diana Carolina Trejo-Osorio

2016-01-01

Augmented Reality applications can serve as teach-ing tools in different contexts of use. Augmented reality appli-cation on mobile devices can help to provide tourist information on cities or to give information on visits to museums. For example, during visits to museums of natural history, applications of augmented reality on mobile devices can be used by some visitors to interact with the skeleton of a whale. However, making rendering heavy models can be computationally infeasible on device...

A Survey on the Reliability of Power Electronics in Electro-Mobility Applications

DEFF Research Database (Denmark)

Gadalla, Brwene Salah Abdelkarim; Schaltz, Erik; Blaabjerg, Frede

2015-01-01

Reliability is an important issue in the field of power electronics since most of the electrical energy is today processed by power electronics. In most of the electro-mobility applications, e.g. electric and hybridelectric vehicles, power electronic are commonly used in very harsh environment...... and extending the service lifetime as well. Research within power electronics is of high interest as it has an important impact in the industry of the electro-mobility applications. According to the aforementioned explanations, this paper will provide an overview of the common factors (thermal cycles, power...... cycles, vibrations, voltage stress and current ripple stress) affecting the reliability of power electronics in electromobility applications. Also, the researchers perspective is summarized from 2001 to 2015....

CBT for depression: a pilot RCT comparing mobile phone vs. computer.

Science.gov (United States)

Watts, Sarah; Mackenzie, Anna; Thomas, Cherian; Griskaitis, Al; Mewton, Louise; Williams, Alishia; Andrews, Gavin

2013-02-07

This paper reports the results of a pilot randomized controlled trial comparing the delivery modality (mobile phone/tablet or fixed computer) of a cognitive behavioural therapy intervention for the treatment of depression. The aim was to establish whether a previously validated computerized program (The Sadness Program) remained efficacious when delivered via a mobile application. 35 participants were recruited with Major Depression (80% female) and randomly allocated to access the program using a mobile app (on either a mobile phone or iPad) or a computer. Participants completed 6 lessons, weekly homework assignments, and received weekly email contact from a clinical psychologist or psychiatrist until completion of lesson 2. After lesson 2 email contact was only provided in response to participant request, or in response to a deterioration in psychological distress scores. The primary outcome measure was the Patient Health Questionnaire 9 (PHQ-9). Of the 35 participants recruited, 68.6% completed 6 lessons and 65.7% completed the 3-months follow up. Attrition was handled using mixed-model repeated-measures ANOVA. Both the Mobile and Computer Groups were associated with statistically significantly benefits in the PHQ-9 at post-test. At 3 months follow up, the reduction seen for both groups remained significant. These results provide evidence to indicate that delivering a CBT program using a mobile application, can result in clinically significant improvements in outcomes for patients with depression. Australian New Zealand Clinical Trials Registry ACTRN 12611001257954.

75 FR 32984 - Policy on the Retention of Supporting Documents and the Use of Electronic Mobile Communication...

Science.gov (United States)

2010-06-10

...-0168] Policy on the Retention of Supporting Documents and the Use of Electronic Mobile Communication... changes regarding the retention of supporting documents and the use of electronic mobile communication... electronic mobile communication/tracking records to be supporting documents, as they record the time, date...

Mobile Computing & Semantic Web für Medizin und Informationsversorgung /Mobile Computing & Semantic Web in Health & Medicine

Directory of Open Access Journals (Sweden)

Van den Brekel, Guus

2011-12-01

Full Text Available Mobile Computing is big and unstoppable. The iPhone and iPad have given an enormous innovative boost to mobile healthcare. Applications, data, software, Operation systems and even Things are going into the “Cloud” to be accessed via Apps by a exponentially growing amount of mobile devices. What is the real magic of these devices? In the design, it’s functionality, in the easy of use, or …? And where exactly is wireless and unlimited Internet access changing healthcare for professionals and patients? What roles do libraries have now in this fast changing world of biomedicine & information technology? And what roles do they really need to develop? Web 2.0 gave users (and librarians power over the web, making connections, interoperability and sharing possible. Who is actually shaping the web 3.0, this World Web Database, the great Internet of Things? Can your library contribute to this? But for whom and why should you? This article will try to merge the possible implications on the long term with practical immediate actions to be taken.

Brain Computer Interfaces for Enhanced Interaction with Mobile Robot Agents

Science.gov (United States)

2016-07-27

SECURITY CLASSIFICATION OF: Brain Computer Interfaces (BCIs) show great potential in allowing humans to interact with computational environments in a...Distribution Unlimited UU UU UU UU 27-07-2016 17-Sep-2013 16-Sep-2014 Final Report: Brain Computer Interfaces for Enhanced Interactions with Mobile Robot...published in peer-reviewed journals: Number of Papers published in non peer-reviewed journals: Final Report: Brain Computer Interfaces for Enhanced

Cross-Border Litigation and ADR Mechanisms in Disputes Concerning Mobile Computing in the EU

DEFF Research Database (Denmark)

Savin, Andrej

2011-01-01

The aim of this paper is to discuss briefly how the EU rules on jurisdiction, choice of law and alternative dispute resolution in civil and commercial matters operate in the context of mobile computing. The article first looks at rules on jurisdiction in commercial disputes, both between businesses...... and between businesses and consumers. It then discusses the choice-of-law issues applicable to mobile computing. Finally, there is an examination of alternative dispute resolution as an alternative to regular courts in transactions involving mobile computing....

Accounting of inter-electron correlations in the model of mobile electron shells

International Nuclear Information System (INIS)

Panov, Yu.D.; Moskvin, A.S.

2000-01-01

One studied the basic peculiar features of the model for mobile electron shells for multielectron atom or cluster. One offered a variation technique to take account of the electron correlations where the coordinates of the centre of single-particle atomic orbital served as variation parameters. It enables to interpret dramatically variation of electron density distribution under anisotropic external effect in terms of the limited initial basis. One studied specific correlated states that might make correlation contribution into the orbital current. Paper presents generalization of the typical MO-LCAO pattern with the limited set of single particle functions enabling to take account of additional multipole-multipole interactions in the cluster [ru

Investigation into Mobile Learning Framework in Cloud Computing Platform

OpenAIRE

Wei, Guo; Joan, Lu

2014-01-01

Abstract—Cloud computing infrastructure is increasingly\\ud used for distributed applications. Mobile learning\\ud applications deployed in the cloud are a new research\\ud direction. The applications require specific development\\ud approaches for effective and reliable communication. This\\ud paper proposes an interdisciplinary approach for design and\\ud development of mobile applications in the cloud. The\\ud approach includes front service toolkit and backend service\\ud toolkit. The front servi...

Activity-Based Support for Mobility and Collaboration in Ubiquitous Computing

DEFF Research Database (Denmark)

Bardram, Jacob Eyvind

2004-01-01

is to: (1) support human activity by managing its collection of work tasks on a computer, (2) support mobility by distributing activities across heterogeneous computing environments, (3) support asynchronous collaboration by allowing several people to participate in an activity, and (4) support...

Improving the capacity, reliability & life of mobile devices with cloud computing

CSIR Research Space (South Africa)

Nkosi, MT

2011-05-01

Full Text Available devices. The approach in this paper is to model the mobile cloud computing process in a 3GPP IMS software development and emulator environment. And show that multimedia and security operations can be performed in the cloud, allowing mobile service...

The electronics revolution inventing the future

CERN Document Server

Williams, J B

2017-01-01

This book is about how electronics, computing, and telecommunications have profoundly changed our lives – the way we work, live, and play. It covers a myriad of topics from the invention of the fundamental devices, and integrated circuits, through radio and television, to computers, mobile telephones and GPS. Today our lives are ruled by electronics as they control the home and computers dominate the workspace. We walk around with mobile phones and communicate by email. Electronics didn’t exist until into the twentieth century. The industrial revolution is the term usually applied to the coming of steam, railways and the factory system. In the twentieth century, it is electronics that has changed the way we gather our information, entertain ourselves, communicate and work. This book demonstrates that this is, in fact, another revolution. .

Electron mobilities of n-type organic semiconductors from time-dependent wavepacket diffusion method: pentacenequinone derivatives.

Science.gov (United States)

Zhang, WeiWei; Zhong, XinXin; Zhao, Yi

2012-11-26

The electron mobilities of two n-type pentacenequinone derivative organic semiconductors, 5,7,12,14-tetraaza-6,13-pentacenequinone (TAPQ5) and 1,4,8,11-tetraaza-6,13-pentacenequinone (TAPQ7), are investigated with use of the methods of electronic structure and quantum dynamics. The electronic structure calculations reveal that the two key parameters for the control of electron transfer, reorganization energy and electronic coupling, are similar for these two isomerization systems, and the charge carriers essentially display one-dimensional transport properties. The mobilities are then calculated by using the time-dependent wavepacket diffusion approach in which the dynamic fluctuations of the electronic couplings are incorporated via their correlation functions obtained from molecular dynamics simulations. The predicted mobility of TAPQ7 crystal is about six times larger than that of TAPQ5 crystal. Most interestingly, Fermi's golden rule predicts the mobilities very close to those from the time-dependent wavepacket diffusion method, even though the electronic couplings are explicitly large enough to make the perturbation theory invalid. The possible reason is analyzed from the dynamic fluctuations.

An Adaptive and Integrated Low-Power Framework for Multicore Mobile Computing

Directory of Open Access Journals (Sweden)

Jongmoo Choi

2017-01-01

Full Text Available Employing multicore in mobile computing such as smartphone and IoT (Internet of Things device is a double-edged sword. It provides ample computing capabilities required in recent intelligent mobile services including voice recognition, image processing, big data analysis, and deep learning. However, it requires a great deal of power consumption, which causes creating a thermal hot spot and putting pressure on the energy resource in a mobile device. In this paper, we propose a novel framework that integrates two well-known low-power techniques, DPM (Dynamic Power Management and DVFS (Dynamic Voltage and Frequency Scaling for energy efficiency in multicore mobile systems. The key feature of the proposed framework is adaptability. By monitoring the online resource usage such as CPU utilization and power consumption, the framework can orchestrate diverse DPM and DVFS policies according to workload characteristics. Real implementation based experiments using three mobile devices have shown that it can reduce the power consumption ranging from 22% to 79%, while affecting negligibly the performance of workloads.

Emerging materials and devices in spintronic integrated circuits for energy-smart mobile computing and connectivity

International Nuclear Information System (INIS)

Kang, S.H.; Lee, K.

2013-01-01

A spintronic integrated circuit (IC) is made of a combination of a semiconductor IC and a dense array of nanometer-scale magnetic tunnel junctions. This emerging field is of growing scientific and engineering interest, owing to its potential to bring disruptive device innovation to the world of electronics. This technology is currently being pursued not only for scalable non-volatile spin-transfer-torque magnetoresistive random access memory, but also for various forms of non-volatile logic (Spin-Logic). This paper reviews recent advances in spintronic IC. Key discoveries and breakthroughs in materials and devices are highlighted in light of the broader perspective of their application in low-energy mobile computing and connectivity systems, which have emerged as leading drivers for the prevailing electronics ecosystem

Teaching and Learning with Mobile Computing Devices: Case Study in K-12 Classrooms

Science.gov (United States)

Grant, Michael M.; Tamim, Suha; Brown, Dorian B.; Sweeney, Joseph P.; Ferguson, Fatima K.; Jones, Lakavious B.

2015-01-01

While ownership of mobile computing devices, such as cellphones, smartphones, and tablet computers, has been rapid, the adoption of these devices in K-12 classrooms has been measured. Some schools and individual teachers have integrated mobile devices to support teaching and learning. The purpose of this qualitative research was to describe the…

New Methods of Mobile Computing: From Smartphones to Smart Education

Science.gov (United States)

Sykes, Edward R.

2014-01-01

Every aspect of our daily lives has been touched by the ubiquitous nature of mobile devices. We have experienced an exponential growth of mobile computing--a trend that seems to have no limit. This paper provides a report on the findings of a recent offering of an iPhone Application Development course at Sheridan College, Ontario, Canada. It…

CBT for depression: a pilot RCT comparing mobile phone vs. computer

Directory of Open Access Journals (Sweden)

Watts Sarah

2013-02-01

Full Text Available Abstract Background This paper reports the results of a pilot randomized controlled trial comparing the delivery modality (mobile phone/tablet or fixed computer of a cognitive behavioural therapy intervention for the treatment of depression. The aim was to establish whether a previously validated computerized program (The Sadness Program remained efficacious when delivered via a mobile application. Method 35 participants were recruited with Major Depression (80% female and randomly allocated to access the program using a mobile app (on either a mobile phone or iPad or a computer. Participants completed 6 lessons, weekly homework assignments, and received weekly email contact from a clinical psychologist or psychiatrist until completion of lesson 2. After lesson 2 email contact was only provided in response to participant request, or in response to a deterioration in psychological distress scores. The primary outcome measure was the Patient Health Questionnaire 9 (PHQ-9. Of the 35 participants recruited, 68.6% completed 6 lessons and 65.7% completed the 3-months follow up. Attrition was handled using mixed-model repeated-measures ANOVA. Results Both the Mobile and Computer Groups were associated with statistically significantly benefits in the PHQ-9 at post-test. At 3 months follow up, the reduction seen for both groups remained significant. Conclusions These results provide evidence to indicate that delivering a CBT program using a mobile application, can result in clinically significant improvements in outcomes for patients with depression. Trial registration Australian New Zealand Clinical Trials Registry ACTRN 12611001257954

An Efficient and Secure m-IPS Scheme of Mobile Devices for Human-Centric Computing

Directory of Open Access Journals (Sweden)

Young-Sik Jeong

2014-01-01

Full Text Available Recent rapid developments in wireless and mobile IT technologies have led to their application in many real-life areas, such as disasters, home networks, mobile social networks, medical services, industry, schools, and the military. Business/work environments have become wire/wireless, integrated with wireless networks. Although the increase in the use of mobile devices that can use wireless networks increases work efficiency and provides greater convenience, wireless access to networks represents a security threat. Currently, wireless intrusion prevention systems (IPSs are used to prevent wireless security threats. However, these are not an ideal security measure for businesses that utilize mobile devices because they do not take account of temporal-spatial and role information factors. Therefore, in this paper, an efficient and secure mobile-IPS (m-IPS is proposed for businesses utilizing mobile devices in mobile environments for human-centric computing. The m-IPS system incorporates temporal-spatial awareness in human-centric computing with various mobile devices and checks users’ temporal spatial information, profiles, and role information to provide precise access control. And it also can extend application of m-IPS to the Internet of things (IoT, which is one of the important advanced technologies for supporting human-centric computing environment completely, for real ubiquitous field with mobile devices.

Electron and hole drift mobility measurements on methylammonium lead iodide perovskite solar cells

Energy Technology Data Exchange (ETDEWEB)

Maynard, Brian; Long, Qi; Schiff, Eric A. [Department of Physics, Syracuse University, Syracuse, New York 13244 (United States); Yang, Mengjin; Zhu, Kai [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Kottokkaran, Ranjith; Abbas, Hisham; Dalal, Vikram L. [Iowa State University, Ames, Iowa 50011 (United States)

2016-04-25

We report nanosecond domain time-of-flight measurements of electron and hole photocarriers in methylammonium lead iodide perovskite solar cells. The mobilities ranged from 0.06 to 1.4 cm{sup 2}/Vs at room temperature, but there is little systematic difference between the two carriers. We also find that the drift mobilities are dispersive (time-dependent). The dispersion parameters are in the range of 0.4–0.7, and they imply that terahertz domain mobilities will be much larger than nanosecond domain mobilities. The temperature-dependences of the dispersion parameters are consistent with confinement of electron and hole transport to fractal-like spatial networks within nanoseconds of their photogeneration.

Theoretical interpretation of the electron mobility behavior in InAs nanowires

International Nuclear Information System (INIS)

Marin, E. G.; Ruiz, F. G.; Godoy, A.; Tienda-Luna, I. M.; Martínez-Blanque, C.; Gámiz, F.

2014-01-01

This work studies the electron mobility in InAs nanowires (NWs), by solving the Boltzmann Transport Equation under the Momentum Relaxation Time approximation. The numerical solver takes into account the contribution of the main scattering mechanisms present in III-V compound semiconductors. It is validated against experimental field effect-mobility results, showing a very good agreement. The mobility dependence on the nanowire diameter and carrier density is analyzed. It is found that surface roughness and polar optical phonons are the scattering mechanisms that mainly limit the mobility behavior. Finally, we explain the origin of the oscillations observed in the mobility of small NWs at high electric fields.

Theoretical interpretation of the electron mobility behavior in InAs nanowires

Energy Technology Data Exchange (ETDEWEB)

Marin, E. G., E-mail: egmarin@ugr.es; Ruiz, F. G., E-mail: franruiz@ugr.es; Godoy, A.; Tienda-Luna, I. M.; Martínez-Blanque, C.; Gámiz, F. [Departamento de Electrónica y Tecnología de los Computadores, Facultad de Ciencias, Universidad de Granada, Av. Fuentenueva S/N, 18071 Granada (Spain)

2014-11-07

This work studies the electron mobility in InAs nanowires (NWs), by solving the Boltzmann Transport Equation under the Momentum Relaxation Time approximation. The numerical solver takes into account the contribution of the main scattering mechanisms present in III-V compound semiconductors. It is validated against experimental field effect-mobility results, showing a very good agreement. The mobility dependence on the nanowire diameter and carrier density is analyzed. It is found that surface roughness and polar optical phonons are the scattering mechanisms that mainly limit the mobility behavior. Finally, we explain the origin of the oscillations observed in the mobility of small NWs at high electric fields.

A Variable Impacts Measurement in Random Forest for Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Jae-Hee Hur

2017-01-01

Full Text Available Recently, the importance of mobile cloud computing has increased. Mobile devices can collect personal data from various sensors within a shorter period of time and sensor-based data consists of valuable information from users. Advanced computation power and data analysis technology based on cloud computing provide an opportunity to classify massive sensor data into given labels. Random forest algorithm is known as black box model which is hardly able to interpret the hidden process inside. In this paper, we propose a method that analyzes the variable impact in random forest algorithm to clarify which variable affects classification accuracy the most. We apply Shapley Value with random forest to analyze the variable impact. Under the assumption that every variable cooperates as players in the cooperative game situation, Shapley Value fairly distributes the payoff of variables. Our proposed method calculates the relative contributions of the variables within its classification process. In this paper, we analyze the influence of variables and list the priority of variables that affect classification accuracy result. Our proposed method proves its suitability for data interpretation in black box model like a random forest so that the algorithm is applicable in mobile cloud computing environment.

76 FR 41523 - In the Matter of Certain Mobile Communications and Computer Devices and Components Thereof...

Science.gov (United States)

2011-07-14

... in its entirety Inv. No. 337-TA-704, Certain Mobile Communications and Computer Devices and... importation of certain mobile communications and computer devices and components thereof by reason of... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-704] In the Matter of Certain Mobile...

75 FR 8399 - In the Matter of Certain Mobile Communications and Computer Devices and Components Thereof...

Science.gov (United States)

2010-02-24

... States after importation of certain mobile communications and computer devices and components thereof by... importation of certain mobile communications or computer devices or components thereof that infringe one or... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-704] In the Matter of Certain Mobile...

Performance Evaluation of a Mobile Wireless Computational Grid ...

African Journals Online (AJOL)

This work developed and simulated a mathematical model for a mobile wireless computational Grid architecture using networks of queuing theory. This was in order to evaluate the performance of theload-balancing three tier hierarchical configuration. The throughput and resource utilizationmetrics were measured and the ...

Temperature dependence of ballistic mobility in a metamorphic InGaAs/InAlAs high electron mobility transistor

International Nuclear Information System (INIS)

Lee, Jongkyong; Gang, Suhyun; Jo, Yongcheol; Kim, Jongmin; Woo, Hyeonseok; Han, Jaeseok; Kim, Hyungsang; Im, Hyunsik

2014-01-01

We have investigated the temperature dependence of ballistic mobility in a 100 nm-long InGaAs/InAlAs metamorphic high-electron-mobility transistor designed for millimeter-wavelength RF applications. To extract the temperature dependence of quasi-ballistic mobility, our experiment involves measurements of the effective mobility in the low-bias linear region of the transistor and of the collision-dominated Hall mobility using a gated Hall bar of the same epitaxial structure. The data measured from the experiment are consistent with that of modeled ballistic mobility based on ballistic transport theory. These results advance the understanding of ballistic transport in various transistors with a nano-scale channel length that is comparable to the carrier's mean free path in the channel.

Electron mobility limited by optical phonons in wurtzite InGaN/GaN core-shell nanowires

Science.gov (United States)

Liu, W. H.; Qu, Y.; Ban, S. L.

2017-09-01

Based on the force-balance and energy-balance equations, the optical phonon-limited electron mobility in InxGa1-xN/GaN core-shell nanowires (CSNWs) is discussed. It is found that the electrons tend to distribute in the core of the CSNWs due to the strong quantum confinement. Thus, the scattering from first kind of the quasi-confined optical (CO) phonons is more important than that from the interface (IF) and propagating (PR) optical phonons. Ternary mixed crystal and size effects on the electron mobility are also investigated. The results show that the PR phonons exist while the IF phonons disappear when the indium composition x < 0.047, and vice versa. Accordingly, the total electron mobility μ first increases and then decreases with indium composition x, and reaches a peak value of approximately 3700 cm2/(V.s) when x = 0.047. The results also show that the mobility μ increases as increasing the core radius of CSNWs due to the weakened interaction between the electrons and CO phonons. The total electron mobility limited by the optical phonons exhibits an obvious enhancement as decreasing temperature or increasing line electron density. Our theoretical results are expected to be helpful to develop electronic devices based on CSNWs.

Crowd-Funding: A New Resource Cooperation Mode for Mobile Cloud Computing.

Science.gov (United States)

Zhang, Nan; Yang, Xiaolong; Zhang, Min; Sun, Yan

2016-01-01

Mobile cloud computing, which integrates the cloud computing techniques into the mobile environment, is regarded as one of the enabler technologies for 5G mobile wireless networks. There are many sporadic spare resources distributed within various devices in the networks, which can be used to support mobile cloud applications. However, these devices, with only a few spare resources, cannot support some resource-intensive mobile applications alone. If some of them cooperate with each other and share their resources, then they can support many applications. In this paper, we propose a resource cooperative provision mode referred to as "Crowd-funding", which is designed to aggregate the distributed devices together as the resource provider of mobile applications. Moreover, to facilitate high-efficiency resource management via dynamic resource allocation, different resource providers should be selected to form a stable resource coalition for different requirements. Thus, considering different requirements, we propose two different resource aggregation models for coalition formation. Finally, we may allocate the revenues based on their attributions according to the concept of the "Shapley value" to enable a more impartial revenue share among the cooperators. It is shown that a dynamic and flexible resource-management method can be developed based on the proposed Crowd-funding model, relying on the spare resources in the network.

Crowd-Funding: A New Resource Cooperation Mode for Mobile Cloud Computing.

Directory of Open Access Journals (Sweden)

Nan Zhang

Full Text Available Mobile cloud computing, which integrates the cloud computing techniques into the mobile environment, is regarded as one of the enabler technologies for 5G mobile wireless networks. There are many sporadic spare resources distributed within various devices in the networks, which can be used to support mobile cloud applications. However, these devices, with only a few spare resources, cannot support some resource-intensive mobile applications alone. If some of them cooperate with each other and share their resources, then they can support many applications. In this paper, we propose a resource cooperative provision mode referred to as "Crowd-funding", which is designed to aggregate the distributed devices together as the resource provider of mobile applications. Moreover, to facilitate high-efficiency resource management via dynamic resource allocation, different resource providers should be selected to form a stable resource coalition for different requirements. Thus, considering different requirements, we propose two different resource aggregation models for coalition formation. Finally, we may allocate the revenues based on their attributions according to the concept of the "Shapley value" to enable a more impartial revenue share among the cooperators. It is shown that a dynamic and flexible resource-management method can be developed based on the proposed Crowd-funding model, relying on the spare resources in the network.

A Survey on Mobile Edge Networks: Convergence of Computing, Caching and Communications

OpenAIRE

Wang, Shuo; Zhang, Xing; Zhang, Yan; Wang, Lin; Yang, Juwo; Wang, Wenbo

2017-01-01

As the explosive growth of smart devices and the advent of many new applications, traffic volume has been growing exponentially. The traditional centralized network architecture cannot accommodate such user demands due to heavy burden on the backhaul links and long latency. Therefore, new architectures which bring network functions and contents to the network edge are proposed, i.e., mobile edge computing and caching. Mobile edge networks provide cloud computing and caching capabilities at th...

Is remanufacturing effective and eco-efficient?: An analysis of the eco-efficiency of personal computers and mobile phones

OpenAIRE

Quariguasi Frota Neto, João; Bloemhof-Ruwaard, Jacqueline

2009-01-01

textabstractRemanufacturing has long been perceived as an environmentally-friendly initiative, and it is therefore sup- ported by a number of governments, in particular in Europe. Yet, the assumption that remanufacturing is desirable to society has never been systematically investigated. In this paper, we focus our attention on the electronics industry. In particular, we take a close look at remanufacturing within the personal computer and mobile phone industries. We investigate whether reman...

Control of a mobile robot through brain computer interface

Directory of Open Access Journals (Sweden)

Robinson Jimenez Moreno

2015-07-01

Full Text Available This paper poses a control interface to command the movement of a mobile robot according to signals captured from the user's brain. These signals are acquired and interpreted by Emotiv EPOC device, a 14-electrode type sensor which captures electroencephalographic (EEG signals with high resolution, which, in turn, are sent to a computer for processing. One brain-computer interface (BCI was developed based on the Emotiv software and SDK in order to command the mobile robot from a distance. Functionality tests are performed with the sensor to discriminate shift intentions of a user group, as well as with a fuzzy controller to hold the direction in case of concentration loss. As conclusion, it was possible to obtain an efficient system for robot movements by brain commands.

ALICE Connex : Mobile Volunteer Computing and Edutainment Platform

CERN Document Server

Chalumporn, Gantaphon

2016-01-01

Mobile devices are very powerful and trend to be developed. They have functions that are used in everyday life. One of their main tasks is to be an entertainment devices or gaming platform. A lot of technologies are now accepted and adopted to improve the potential of education. Edutainment is a combination of entertainment and education media together to make use of both benefits. In this work, we introduce a design of edutainment platform which is a part of mobile volunteer computing and edutainment platform called ‘ALICE Connex’ for ALICE at CERN. The edutainment platform focuses to deliver enjoyment and education, while promotes ALICE and Volunteer Computing platform to general public. The design in this work describes the functionality to build an effective edutainment with real-time multiplayer interaction on round-based gameplay, while integrates seamless edutainment with basic particle physic content though game mechanism and items design. For the assessment method we will observe the enjoyment o...

High Thermoelectric Power Factor of High-Mobility 2D Electron Gas.

Science.gov (United States)

Ohta, Hiromichi; Kim, Sung Wng; Kaneki, Shota; Yamamoto, Atsushi; Hashizume, Tamotsu

2018-01-01

Thermoelectric conversion is an energy harvesting technology that directly converts waste heat from various sources into electricity by the Seebeck effect of thermoelectric materials with a large thermopower ( S ), high electrical conductivity (σ), and low thermal conductivity (κ). State-of-the-art nanostructuring techniques that significantly reduce κ have realized high-performance thermoelectric materials with a figure of merit ( ZT = S 2 ∙σ∙ T ∙κ -1 ) between 1.5 and 2. Although the power factor (PF = S 2 ∙σ) must also be enhanced to further improve ZT , the maximum PF remains near 1.5-4 mW m -1 K -2 due to the well-known trade-off relationship between S and σ. At a maximized PF, σ is much lower than the ideal value since impurity doping suppresses the carrier mobility. A metal-oxide-semiconductor high electron mobility transistor (MOS-HEMT) structure on an AlGaN/GaN heterostructure is prepared. Applying a gate electric field to the MOS-HEMT simultaneously modulates S and σ of the high-mobility electron gas from -490 µV K -1 and ≈10 -1 S cm -1 to -90 µV K -1 and ≈10 4 S cm -1 , while maintaining a high carrier mobility (≈1500 cm 2 V -1 s -1 ). The maximized PF of the high-mobility electron gas is ≈9 mW m -1 K -2 , which is a two- to sixfold increase compared to state-of-the-art practical thermoelectric materials.

Mobile computing device as tools for college student education: a case on flashcards application

Science.gov (United States)

Kang, Congying

2012-04-01

Traditionally, college students always use flash cards as a tool to remember massive knowledge, such as nomenclature, structures, and reactions in chemistry. Educational and information technology have enabled flashcards viewed on computers, like Slides and PowerPoint, works as tunnels of drilling and feedback for the learners. The current generation of students is more capable of information technology and mobile computing devices. For example, they use their Mobile phones much more intensively everyday day. Trends of using Mobile phone as an educational tool is analyzed and a educational technology initiative is proposed, which use Mobile phone flash cards applications to help students learn biology and chemistry. Experiments show that users responded positively to these mobile flash cards.

Ultimate response time of high electron mobility transistors

International Nuclear Information System (INIS)

Rudin, Sergey; Rupper, Greg; Shur, Michael

2015-01-01

We present theoretical studies of the response time of the two-dimensional gated electron gas to femtosecond pulses. Our hydrodynamic simulations show that the device response to a short pulse or a step-function signal is either smooth or oscillating time-decay at low and high mobility, μ, values, respectively. At small gate voltage swings, U 0  = U g  − U th , where U g is the gate voltage and U th is the threshold voltage, such that μU 0 /L < v s , where L is the channel length and v s is the effective electron saturation velocity, the decay time in the low mobility samples is on the order of L 2 /(μU 0 ), in agreement with the analytical drift model. However, the decay is preceded by a delay time on the order of L/s, where s is the plasma wave velocity. This delay is the ballistic transport signature in collision-dominated devices, which becomes important during very short time periods. In the high mobility devices, the period of the decaying oscillations is on the order of the plasma wave velocity transit time. Our analysis shows that short channel field effect transistors operating in the plasmonic regime can meet the requirements for applications as terahertz detectors, mixers, delay lines, and phase shifters in ultra high-speed wireless communication circuits

The Effects of Mobile-Computer-Supported Collaborative Learning: Meta-Analysis and Critical Synthesis

Science.gov (United States)

Sung, Yao-Ting; Yang, Je-Ming; Lee, Han-Yueh

2017-01-01

One of the trends in collaborative learning is using mobile devices for supporting the process and products of collaboration, which has been forming the field of mobile-computer-supported collaborative learning (mCSCL). Although mobile devices have become valuable collaborative learning tools, evaluative evidence for their substantial…

78 FR 54453 - Notice of Public Meeting-Intersection of Cloud Computing and Mobility Forum and Workshop

Science.gov (United States)

2013-09-04

...--Intersection of Cloud Computing and Mobility Forum and Workshop AGENCY: National Institute of Standards and.../intersection-of-cloud-and-mobility.cfm . SUPPLEMENTARY INFORMATION: NIST hosted six prior Cloud Computing Forum... interoperability, portability, and security, discuss the Federal Government's experience with cloud computing...

Rational design of metal-organic electronic devices: A computational perspective

Science.gov (United States)

Chilukuri, Bhaskar

Organic and organometallic electronic materials continue to attract considerable attention among researchers due to their cost effectiveness, high flexibility, low temperature processing conditions and the continuous emergence of new semiconducting materials with tailored electronic properties. In addition, organic semiconductors can be used in a variety of important technological devices such as solar cells, field-effect transistors (FETs), flash memory, radio frequency identification (RFID) tags, light emitting diodes (LEDs), etc. However, organic materials have thus far not achieved the reliability and carrier mobility obtainable with inorganic silicon-based devices. Hence, there is a need for finding alternative electronic materials other than organic semiconductors to overcome the problems of inferior stability and performance. In this dissertation, I research the development of new transition metal based electronic materials which due to the presence of metal-metal, metal-pi, and pi-pi interactions may give rise to superior electronic and chemical properties versus their organic counterparts. Specifically, I performed computational modeling studies on platinum based charge transfer complexes and d 10 cyclo-[M(mu-L)]3 trimers (M = Ag, Au and L = monoanionic bidentate bridging (C/N~C/N) ligand). The research done is aimed to guide experimental chemists to make rational choices of metals, ligands, substituents in synthesizing novel organometallic electronic materials. Furthermore, the calculations presented here propose novel ways to tune the geometric, electronic, spectroscopic, and conduction properties in semiconducting materials. In addition to novel material development, electronic device performance can be improved by making a judicious choice of device components. I have studied the interfaces of a p-type metal-organic semiconductor viz cyclo-[Au(mu-Pz)] 3 trimer with metal electrodes at atomic and surface levels. This work was aimed to guide the device

Software Defined Resource Orchestration System for Multitask Application in Heterogeneous Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Qi Qi

2016-01-01

Full Text Available The mobile cloud computing (MCC that combines mobile computing and cloud concept takes wireless access network as the transmission medium and uses mobile devices as the client. When offloading the complicated multitask application to the MCC environment, each task executes individually in terms of its own computation, storage, and bandwidth requirement. Due to user’s mobility, the provided resources contain different performance metrics that may affect the destination choice. Nevertheless, these heterogeneous MCC resources lack integrated management and can hardly cooperate with each other. Thus, how to choose the appropriate offload destination and orchestrate the resources for multitask is a challenge problem. This paper realizes a programming resource provision for heterogeneous energy-constrained computing environments, where a software defined controller is responsible for resource orchestration, offload, and migration. The resource orchestration is formulated as multiobjective optimal problem that contains the metrics of energy consumption, cost, and availability. Finally, a particle swarm algorithm is used to obtain the approximate optimal solutions. Simulation results show that the solutions for all of our studied cases almost can hit Pareto optimum and surpass the comparative algorithm in approximation, coverage, and execution time.

Resonant tunneling assisted propagation and amplification of plasmons in high electron mobility transistors

International Nuclear Information System (INIS)

Bhardwaj, Shubhendu; Sensale-Rodriguez, Berardi; Xing, Huili Grace; Rajan, Siddharth; Volakis, John L.

2016-01-01

A rigorous theoretical and computational model is developed for the plasma-wave propagation in high electron mobility transistor structures with electron injection from a resonant tunneling diode at the gate. We discuss the conditions in which low-loss and sustainable plasmon modes can be supported in such structures. The developed analytical model is used to derive the dispersion relation for these plasmon-modes. A non-linear full-wave-hydrodynamic numerical solver is also developed using a finite difference time domain algorithm. The developed analytical solutions are validated via the numerical solution. We also verify previous observations that were based on a simplified transmission line model. It is shown that at high levels of negative differential conductance, plasmon amplification is indeed possible. The proposed rigorous models can enable accurate design and optimization of practical resonant tunnel diode-based plasma-wave devices for terahertz sources, mixers, and detectors, by allowing a precise representation of their coupling when integrated with other electromagnetic structures

Electron mobility in nonpolar liquids: the effect of molecular structure, temperature and electric field

International Nuclear Information System (INIS)

Schmidt, W.F.

1977-01-01

A survey is given on the mobility of excess electrons in liquid hydrocarbons and related compounds. It was found that the mobility is strongly influenced by the molecular structure of the liquid, by the temperature, and by the electric field strength. The mobility in hydrocarbons increases as the shape of the molecule approaches a sphere. The temperature coefficient is positive in most liquids over a limited temperature although exceptions have been observed in liquid methane. The field dependence of the mobility in high mobility liquids (>10 cm 2 V -1 s -1 ) showed a decrease of the mobility at higher field strengths while in low mobility liquids ( 2 V -1 s -1 ) it showed an increase. These results are discussed on the basis of the extended and the localized electron models. The predictions of these theories are compared with the experimental results and conclusions on the validity of the underlying assumptions are drawn. (author)

Computer electronics made simple computerbooks

CERN Document Server

Bourdillon, J F B

1975-01-01

Computer Electronics: Made Simple Computerbooks presents the basics of computer electronics and explains how a microprocessor works. Various types of PROMs, static RAMs, dynamic RAMs, floppy disks, and hard disks are considered, along with microprocessor support devices made by Intel, Motorola and Zilog. Bit slice logic and some AMD bit slice products are also described. Comprised of 14 chapters, this book begins with an introduction to the fundamentals of hardware design, followed by a discussion on the basic building blocks of hardware (NAND, NOR, AND, OR, NOT, XOR); tools and equipment that

Thermal Investigation of Three-Dimensional GaN-on-SiC High Electron Mobility Transistors

Science.gov (United States)

2017-07-01

University of L’Aquila, (2011). 23 Rao, H. & Bosman, G. Hot-electron induced defect generation in AlGaN/GaN high electron mobility transistors. Solid...AFRL-RY-WP-TR-2017-0143 THERMAL INVESTIGATION OF THREE- DIMENSIONAL GaN-on-SiC HIGH ELECTRON MOBILITY TRANSISTORS Qing Hao The University of Arizona...clarification memorandum dated 16 Jan 09. This report is available to the general public, including foreign nationals. Copies may be obtained from the

The electron mobility and thermoelectric power in InSb at atmospheric and hydrostatic pressures

International Nuclear Information System (INIS)

Litwin-Staszewska, E.; Piotrzkowski, R.; Szymanska, W.

1981-01-01

First, theoretical calculations of electron mobility and thermoelectric power in n-type InSb are reported at liquid nitrogen and room temperatures. All the scattering mechanisms of importance in InSb are taken into account. The calculations based upon a variational solution of the Boltzmann equation are compared with experimental results over the whole available range of electron concentrations. Good agreement between theoretical and experimental results is obtained using the value of deformation potential constant C = 14.6 eV. Secondly, both, experimental and theoretical investigations are made of mobility in InSb under hydrostatic pressure at 77 K within a wide range of electron concentrations. The smallest electron concentrations obtained by freezing the conduction electrons on the metastable states are of order of 1x10 12 cm -3 . Also for those smallest concentration it is possible to describe theoretically the dependence of mobility on the hydrostatic pressure using the same set of parameters as previously, and assuming some compensation of donors by acceptors. (author)

Temperature dependence of electron mobility, electroluminescence and photoluminescence of Alq{sub 3} in OLED

Energy Technology Data Exchange (ETDEWEB)

Mu Haichuan; White, Dan; Sharpton, Buck [Office of Electronic Miniaturization, University of Alaska at Fairbanks, AK 99701 (United States); Klotzkin, David [Department of Electrical and Computer Engineering and Computer Sciences, University of Cincinnati, Cincinnati, OH 45221 (United States); De Silva, Ajith; Wagner, Hans Peter [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States)], E-mail: fnhm@uaf.edu

2008-12-07

The correlation of electroluminescence (EL), photoluminescence (PL) and electron mobility were investigated over temperature from 60 to 300 K in small-molecule organic light emitting diode (OLED) structures. The devices consisted of ITO/PEDOT(50 nm)/TPD(50 nm)/Alq{sub 3}(60 nm)/LiF(1 nm)/Al(90 nm), and were fabricated with high-vacuum sublimation/evaporation in a cross-linked configuration. Electron mobility was measured using an ac analysis of the device optical modulation characteristics, while PL and EL were measured by measuring optical power out at fixed pump power of 1 mW, and analysis of dc brightness-voltage (L-V) characteristics, respectively. PL intensity and mobility had a clear maximum at around 220 K, while EL efficiency was constant below 220 K and decrease monotonically above. The reason for the temperature dependent EL, PL and electron mobility behaviour will be discussed.

Effect of the hydrostatic pressure on the electron mobility in delta-doped systems

Energy Technology Data Exchange (ETDEWEB)

Oubram, O; Mora-Ramos, M E; Gaggero-Sager, L M, E-mail: 1gaggero@uaem.m [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico)

2009-05-01

The influence of hydrostatic pressure on the electron states and low-temperature mobility in n-type GaAs delta-doped single quantum wells is studied. Values of hydrostatic pressure consider are below the so-called GAMMA-X crossover, keeping all attention in the electronic properties at the Brillouin zone center. The effect of the pressure on the electron mobility is described via a relative quantity that is proportional to the ratio between P not = 0 and zero pressure results. Calculation is performed using an analytical description of the potential energy function profile, based on the Thomas-Fermi approach, taking explicitly into account the dependence upon P of the main input parameters: effective masses and dielectric constant. The relative mobility increases for higher values of P. The cases of zero and finite -although small- temperature are studied, showing that the influence of T is mainly to lower the values of the relative mobility in the entire range of P considered. Numerical results are reported for a two-dimensional density of ionized impurities equals to 7.5 x 10{sup 12} cm{sup -2}.

Human Pacman: A Mobile Augmented Reality Entertainment System Based on Physical, Social, and Ubiquitous Computing

Science.gov (United States)

Cheok, Adrian David

This chapter details the Human Pacman system to illuminate entertainment computing which ventures to embed the natural physical world seamlessly with a fantasy virtual playground by capitalizing on infrastructure provided by mobile computing, wireless LAN, and ubiquitous computing. With Human Pacman, we have a physical role-playing computer fantasy together with real human-social and mobile-gaming that emphasizes on collaboration and competition between players in a wide outdoor physical area that allows natural wide-area human-physical movements. Pacmen and Ghosts are now real human players in the real world experiencing mixed computer graphics fantasy-reality provided by using the wearable computers on them. Virtual cookies and actual tangible physical objects are incorporated into the game play to provide novel experiences of seamless transitions between the real and virtual worlds. This is an example of a new form of gaming that anchors on physicality, mobility, social interaction, and ubiquitous computing.

The feasibility of mobile computing for on-site inspection.

Energy Technology Data Exchange (ETDEWEB)

Horak, Karl Emanuel; DeLand, Sharon Marie; Blair, Dianna Sue

2014-09-01

With over 5 billion cellphones in a world of 7 billion inhabitants, mobile phones are the most quickly adopted consumer technology in the history of the world. Miniaturized, power-efficient sensors, especially video-capable cameras, are becoming extremely widespread, especially when one factors in wearable technology like Apples Pebble, GoPro video systems, Google Glass, and lifeloggers. Tablet computers are becoming more common, lighter weight, and power-efficient. In this report the authors explore recent developments in mobile computing and their potential application to on-site inspection for arms control verification and treaty compliance determination. We examine how such technology can effectively be applied to current and potential future inspection regimes. Use cases are given for both host-escort and inspection teams. The results of field trials and their implications for on-site inspections are discussed.

Low Computational Complexity Network Coding For Mobile Networks

DEFF Research Database (Denmark)

Heide, Janus

2012-01-01

Network Coding (NC) is a technique that can provide benefits in many types of networks, some examples from wireless networks are: In relay networks, either the physical or the data link layer, to reduce the number of transmissions. In reliable multicast, to reduce the amount of signaling and enable......-flow coding technique. One of the key challenges of this technique is its inherent computational complexity which can lead to high computational load and energy consumption in particular on the mobile platforms that are the target platform in this work. To increase the coding throughput several...

Development of mobile platform integrated with existing electronic medical records.

Science.gov (United States)

Kim, YoungAh; Kim, Sung Soo; Kang, Simon; Kim, Kyungduk; Kim, Jun

2014-07-01

This paper describes a mobile Electronic Medical Record (EMR) platform designed to manage and utilize the existing EMR and mobile application with optimized resources. We structured the mEMR to reuse services of retrieval and storage in mobile app environments that have already proven to have no problem working with EMRs. A new mobile architecture-based mobile solution was developed in four steps: the construction of a server and its architecture; screen layout and storyboard making; screen user interface design and development; and a pilot test and step-by-step deployment. This mobile architecture consists of two parts, the server-side area and the client-side area. In the server-side area, it performs the roles of service management for EMR and documents and for information exchange. Furthermore, it performs menu allocation depending on user permission and automatic clinical document architecture document conversion. Currently, Severance Hospital operates an iOS-compatible mobile solution based on this mobile architecture and provides stable service without additional resources, dealing with dynamic changes of EMR templates. The proposed mobile solution should go hand in hand with the existing EMR system, and it can be a cost-effective solution if a quality EMR system is operated steadily with this solution. Thus, we expect this example to be shared with hospitals that currently plan to deploy mobile solutions.

The unexpected beneficial effect of the L-valley population on the electron mobility of GaAs nanowires

International Nuclear Information System (INIS)

Marin, E. G.; Ruiz, F. G.; Godoy, A.; Tienda-Luna, I. M.; Gámiz, F.

2015-01-01

The impact of the L-valley population on the transport properties of GaAs cylindrical nanowires (NWs) is analyzed by numerically calculating the electron mobility under the momentum relaxation time approximation. In spite of its low contribution to the electron mobility (even for high electron populations in small NWs), it is demonstrated to have a beneficial effect, since it significantly favours the Γ-valley mobility by screening the higher Γ-valley energy subbands

Report on the Audit of the Use of Mobile Computers -- Air Force

Science.gov (United States)

1991-02-15

We are providing this final report on the Audit of the Use of Mobile Computers--Air Force for your review and comments. The audit was conducted from...November 1989 through August 1990. The audit was part of our review of the use of mobile computers throughout DoD. Our overall objectives were to...operate, and maintain. The audit showed that the Air Force needed to retain no more than 5 of the 18 TSS’s. This would save the Air Force $27.3 million (Enclosure 2).

Offloading Method for Efficient Use of Local Computational Resources in Mobile Location-Based Services Using Clouds

Directory of Open Access Journals (Sweden)

Yunsik Son

2017-01-01

Full Text Available With the development of mobile computing, location-based services (LBSs have been developed to provide services based on location information through communication networks or the global positioning system. In recent years, LBSs have evolved into smart LBSs, which provide many services using only location information. These include basic services such as traffic, logistic, and entertainment services. However, a smart LBS may require relatively complicated operations, which may not be effectively performed by the mobile computing system. To overcome this problem, a computation offloading technique can be used to perform certain tasks on mobile devices in cloud and fog environments. Furthermore, mobile platforms exist that provide smart LBSs. The smart cross-platform is a solution based on a virtual machine (VM that enables compatibility of content in various mobile and smart device environments. However, owing to the nature of the VM-based execution method, the execution performance is degraded compared to that of the native execution method. In this paper, we introduce a computation offloading technique that utilizes fog computing to improve the performance of VMs running on mobile devices. We applied the proposed method to smart devices with a smart VM (SVM and HTML5 SVM to compare their performances.

An enhanced technique for mobile cloudlet offloading with reduced computation using compression in the cloud

Science.gov (United States)

Moro, A. C.; Nadesh, R. K.

2017-11-01

The cloud computing paradigm has transformed the way we do business in today’s world. Services on cloud have come a long way since just providing basic storage or software on demand. One of the fastest growing factor in this is mobile cloud computing. With the option of offloading now available to mobile users, mobile users can offload entire applications onto cloudlets. With the problems regarding availability and limited-storage capacity of these mobile cloudlets, it becomes difficult to decide for the mobile user when to use his local memory or the cloudlets. Hence, we take a look at a fast algorithm that decides whether the mobile user should go for cloudlet or rely on local memory based on an offloading probability. We have partially implemented the algorithm which decides whether the task can be carried out locally or given to a cloudlet. But as it becomes a burden on the mobile devices to perform the complete computation, so we look to offload this on to a cloud in our paper. Also further we use a file compression technique before sending the file onto the cloud to further reduce the load.

Electric field dependence of the electron mobility in bulk wurtzite ZnO

Indian Academy of Sciences (India)

Electric field dependence of the electron mobility in bulk wurtzite ZnO. K ALFARAMAWI ... tion to ultraviolet light emitters, gas sensors, surface acoustic wave devices and ..... Dorkel J M and Leturcq P H 1981 Solid-State Electron. 24 8211.

Finishing of display glass for mobile electronics using 3M Trizact diamond tile abrasive pads

Science.gov (United States)

Zheng, Lianbin; Fletcher, Tim; Na, Tee Koon; Sventek, Bruce; Romero, Vince; Lugg, Paul S.; Kim, Don

2010-10-01

This paper will describe a new method being used during the finishing of glass displays for mobile electronics including mobile hand held devices and notebook computers. The new method consists of using 3M TrizactTM Diamond Tile Abrasive Pads. TrizactTM Diamond Tile is a structured fixed abrasive grinding technology developed by 3M Company. The TrizactTM Diamond Tile structured abrasive pad consists of an organic (polymeric binder) - inorganic (abrasive mineral, i.e., diamond) composite that is used with a water-based coolant. TrizactTM Diamond Tile technology can be applied in both double and single side grinding applications. A unique advantage of TrizactTM Diamond Tile technology is the combination of high stock removal and low sub-surface damage. Grinding results will be presented for both 9 micron and 20 micron grades of TrizactTM Diamond Tile abrasive pads used to finish several common display glasses including Corning GorillaTM glass and Soda Lime glass.

Two dimensional electron systems for solid state quantum computation

Science.gov (United States)

Mondal, Sumit

Two dimensional electron systems based on GaAs/AlGaAs heterostructures are extremely useful in various scientific investigations of recent times including the search for quantum computational schemes. Although significant strides have been made over the past few years to realize solid state qubits on GaAs/AlGaAs 2DEGs, there are numerous factors limiting the progress. We attempt to identify factors that have material and design-specific origin and develop ways to overcome them. The thesis is divided in two broad segments. In the first segment we describe the realization of a new field-effect induced two dimensional electron system on GaAs/AlGaAs heterostructure where the novel device-design is expected to suppress the level of charge noise present in the device. Modulation-doped GaAs/AlGaAs heterostructures are utilized extensively in the study of quantum transport in nanostructures, but charge fluctuations associated with remote ionized dopants often produce deleterious effects. Electric field-induced carrier systems offer an attractive alternative if certain challenges can be overcome. We demonstrate a field-effect transistor in which the active channel is locally devoid of modulation-doping, but silicon dopant atoms are retained in the ohmic contact region to facilitate low-resistance contacts. A high quality two-dimensional electron gas is induced by a field-effect that is tunable over a density range of 6.5x10 10cm-2 to 2.6x1011cm-2 . Device design, fabrication, and low temperature (T=0.3K) characterization results are discussed. The demonstrated device-design overcomes several existing limitations in the fabrication of field-induced 2DEGs and might find utility in hosting nanostructures required for making spin qubits. The second broad segment describes our effort to correlate transport parameters measured at T=0.3K to the strength of the fractional quantum Hall state observed at nu=5/2 in the second Landau level of high-mobility GaAs/AlGaAs two dimensional

Calculation of the mobility of electrons injected in liquid argon

International Nuclear Information System (INIS)

Ascarelli, G.

1986-01-01

A model calculation is carried out in which we evaluate the mobility of electrons injected in liquid argon. Scattering by both phonons and static density fluctuations is taken into account. The calculation for the mobility limited by phonon scattering differs from the usual calculation in crystals by considering both the local changes in the deformation potential and the changes of the amplitude of the phonons that are caused by the existence of density fluctuations. The calculation of the mobility limited by scattering from density fluctuations is carried out with the assumption that they give rise to a square-well (or barrier) potential that will scatter the electrons. The above perturbation ΔV 0 is related to a density fluctuation Δn by ΔV 0 = V 0 (n-bar+Δn)-V 0 (n-bar). The scattering volumes Ω, where the density fluctuation Δn is located, are weighted by exp(-r/xi) where xi is the correlation length and r is the radius of Ω. The magnitude of the different density fluctuations is weighted by exp[-(Δn) 2 Ω/2nS(0)], where S(0) = nk/sub B/TK/sub T/, K/sub T/ is the isothermal compressibility. The calculation of the mean free path is carried out using partial waves. Both scattering mechanisms, scattering by phonons and static density fluctuations, give comparable contributions to the mobility

Mobile Cloud Computing: Resource Discovery, Session Connectivity and Other Open Issues

NARCIS (Netherlands)

Schüring, Markus; Karagiannis, Georgios

2011-01-01

Abstract—Cloud computing can be considered as a model that provides network access to a shared pool of resources, such as storage and computing power, which can be rapidly provisioned and released with minimal management effort. This paper describes a research activity in the area of mobile cloud

77 FR 49458 - Certain Mobile Electronic Devices Incorporating Haptics; Amendment of the Complaint and Notice of...

Science.gov (United States)

2012-08-16

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-834] Certain Mobile Electronic Devices.... 1337 in the importation, sale for importation, and sale within the United States after importation of certain mobile electronic devices incorporating haptics, by reason of the infringement of claims of six...

Exploring the Use of Electronic Mobile Technologies among Distance Learners in Rural Communities for Safe and Disruptive Learning

Science.gov (United States)

Ntloedibe-Kuswani, Gomang Seratwa

2013-01-01

Several studies indicated the potential of electronic mobile technologies in reaching (safe learning) under-served communities and engaging (disruptive learning) disadvantaged peoples affording them learning experiences. However, the potential benefits of (electronic mobile learning) e-mobile learning have not been well understood from the…

Effectiveness of mobile electronic devices in weight loss among overweight and obese populations: a systematic review and meta-analysis.

Science.gov (United States)

Khokhar, Bushra; Jones, Jessica; Ronksley, Paul E; Armstrong, Marni J; Caird, Jeff; Rabi, Doreen

2014-01-01

Mobile electronic devices, such as mobile phones and PDAs, have emerged as potentially useful tools in the facilitation and maintenance of weight loss. While RCTs have demonstrated a positive impact of mobile interventions, the extent to which mobile electronic devices are more effective than usual care methods is still being debated. Electronic databases were systematically searched for RCTs evaluating the effectiveness of mobile electronic device interventions among overweight and obese adults. Weighted mean difference for change in body weight was the primary outcome. The search strategy yielded 559 citations and of the 108 potentially relevant studies, six met the criteria. A total of 632 participants were included in the six studies reporting a mean change in body weight. Using a random-effects model, the WMD for the effect of using mobile electronic devices on reduction in body weight was -1.09 kg (95% CI -2.12, -0.05). When stratified by the type of mobile electronic device used, it suggests that interventions using mobile phones were effective at achieving weight loss, WMD = -1.78 kg (95% CI -2.92, -0.63). This systematic review and meta-analysis suggests that mobile electronic devices have the potential to facilitate weight loss in overweight and obese populations, but further work is needed to understand if these interventions have sustained benefit and how we can make these mHealth tools most effective on a large scale. As the field of healthcare increasingly utilizes novel mobile technologies, the focus must not be on any one specific device but on the best possible use of these tools to measure and understand behavior. As mobile electronic devices continue to increase in popularity and the associated technology continues to advance, the potential for the use of mobile devices in global healthcare is enormous. More RCTs with larger sample sizes need to be conducted to look at the cost-effectiveness, technical and financial feasibility of adapting such m

77 FR 24514 - Certain Consumer Electronics, Including Mobile Phones and Tablets; Institution of Investigation...

Science.gov (United States)

2012-04-24

..., Including Mobile Phones and Tablets; Institution of Investigation Pursuant to 19 U.S.C. 1337 AGENCY: U.S... mobile phones and tablets, by reason of infringement of certain claims of U.S. Patent No. 5,854,893... after importation of certain consumer electronics, including mobile phones and tablets, that infringe...

Atomdroid: a computational chemistry tool for mobile platforms.

Science.gov (United States)

Feldt, Jonas; Mata, Ricardo A; Dieterich, Johannes M

2012-04-23

We present the implementation of a new molecular mechanics program designed for use in mobile platforms, the first specifically built for these devices. The software is designed to run on Android operating systems and is compatible with several modern tablet-PCs and smartphones available in the market. It includes molecular viewer/builder capabilities with integrated routines for geometry optimizations and Monte Carlo simulations. These functionalities allow it to work as a stand-alone tool. We discuss some particular development aspects, as well as the overall feasibility of using computational chemistry software packages in mobile platforms. Benchmark calculations show that through efficient implementation techniques even hand-held devices can be used to simulate midsized systems using force fields.

Intrinsic mobility limit for anisotropic electron transport in Alq3.

Science.gov (United States)

Drew, A J; Pratt, F L; Hoppler, J; Schulz, L; Malik-Kumar, V; Morley, N A; Desai, P; Shakya, P; Kreouzis, T; Gillin, W P; Kim, K W; Dubroka, A; Scheuermann, R

2008-03-21

Muon spin relaxation has been used to probe the charge carrier motion in the molecular conductor Alq3 (tris[8-hydroxy-quinoline] aluminum). At 290 K, the magnetic field dependence of the muon spin relaxation corresponds to that expected for highly anisotropic intermolecular electron hopping. Intermolecular mobility in the fast hopping direction has been found to be 0.23+/-0.03 cm2 V-1 s(-1) in the absence of an electric- field gradient, increasing to 0.32+/-0.06 cm2 V-1 s(-1) in an electric field gradient of 1 MV m(-1). These intrinsic mobility values provide an estimate of the upper limit for mobility achievable in bulk material.

Cultural Distance-Aware Service Recommendation Approach in Mobile Edge Computing

Directory of Open Access Journals (Sweden)

Yan Li

2018-01-01

Full Text Available In the era of big data, traditional computing systems and paradigms are not efficient and even difficult to use. For high performance big data processing, mobile edge computing is emerging as a complement framework of cloud computing. In this new computing architecture, services are provided within a close proximity of mobile users by servers at the edge of network. Traditional collaborative filtering recommendation approach only focuses on the similarity extracted from the rating data, which may lead to an inaccuracy expression of user preference. In this paper, we propose a cultural distance-aware service recommendation approach which focuses on not only the similarity but also the local characteristics and preference of users. Our approach employs the cultural distance to express the user preference and combines it with similarity to predict the user ratings and recommend the services with higher rating. In addition, considering the extreme sparsity of the rating data, missing rating prediction based on collaboration filtering is introduced in our approach. The experimental results based on real-world datasets show that our approach outperforms the traditional recommendation approaches in terms of the reliability of recommendation.

A novel resource management method of providing operating system as a service for mobile transparent computing.

Science.gov (United States)

Xiong, Yonghua; Huang, Suzhen; Wu, Min; Zhang, Yaoxue; She, Jinhua

2014-01-01

This paper presents a framework for mobile transparent computing. It extends the PC transparent computing to mobile terminals. Since resources contain different kinds of operating systems and user data that are stored in a remote server, how to manage the network resources is essential. In this paper, we apply the technologies of quick emulator (QEMU) virtualization and mobile agent for mobile transparent computing (MTC) to devise a method of managing shared resources and services management (SRSM). It has three layers: a user layer, a manage layer, and a resource layer. A mobile virtual terminal in the user layer and virtual resource management in the manage layer cooperate to maintain the SRSM function accurately according to the user's requirements. An example of SRSM is used to validate this method. Experiment results show that the strategy is effective and stable.

A Novel Resource Management Method of Providing Operating System as a Service for Mobile Transparent Computing

Directory of Open Access Journals (Sweden)

Yonghua Xiong

2014-01-01

Full Text Available This paper presents a framework for mobile transparent computing. It extends the PC transparent computing to mobile terminals. Since resources contain different kinds of operating systems and user data that are stored in a remote server, how to manage the network resources is essential. In this paper, we apply the technologies of quick emulator (QEMU virtualization and mobile agent for mobile transparent computing (MTC to devise a method of managing shared resources and services management (SRSM. It has three layers: a user layer, a manage layer, and a resource layer. A mobile virtual terminal in the user layer and virtual resource management in the manage layer cooperate to maintain the SRSM function accurately according to the user’s requirements. An example of SRSM is used to validate this method. Experiment results show that the strategy is effective and stable.

78 FR 13895 - Certain Consumer Electronics, Including Mobile Phones and Tablets; Commission Determination Not...

Science.gov (United States)

2013-03-01

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-839] Certain Consumer Electronics... importation of certain consumer electronics, including mobile phones and tablets, by reason of infringement of..., Washington (collectively, ``HTC''); LG Electronics, Inc. of Seoul, Republic of Korea, LG Electronics U.S.A...

Pressure effects on electron reactions and mobility in nonpolar liquids

International Nuclear Information System (INIS)

Holroyd, R.A.; Nishikawa, Masaru

2002-01-01

High pressure studies have elucidated the mechanisms of both electron reactions and electron transport in nonpolar liquids and provided information about the partial molar volumes of ions and electrons. The very large volume changes associated with electron attachment reactions have been explained as due to electrostriction by the ions, calculated with a continuum model, but modified to include the formation of a glassy shell of solvent molecules around the ion. The mobilities of electrons in cases where the electron is trapped can now be understood by comparing the trap cavity volume with the volume of electrostriction of the solvent around the cavity. In cases where the electron is quasi-free the compressibility dependent potential fluctuations are shown to be important. The isothermal compressibility is concluded to be the single most important parameter determining the behavior of excess electrons in liquids

Electron mobility on the surface of liquid Helium: influence of surface level atoms and depopulation of lowest subbands

International Nuclear Information System (INIS)

Grigoriev, P. D.; Dyugaev, A. M.; Lebedeva, E. V.

2008-01-01

The temperature dependence of electron mobility is examined. We calculate the contribution to the electron scattering rate from the surface level atoms (SLAs), proposed in [10]. This contribution is substantial at low temperatures T < 0.5, when the He vapor concentration is exponentially small. We also study the effect of depopulation of the lowest energy subband, which leads to an increase in the electron mobility at high temperature. The results explain certain long-standing discrepancies between the existing theory and experiment on electron mobility on the surface of liquid helium

Study of electron mobility in small molecular SAlq by transient electroluminescence method

Science.gov (United States)

Kumar, Pankaj; Jain, S. C.; Kumar, Vikram; Chand, Suresh; Kamalasanan, M. N.; Tandon, R. P.

2007-12-01

The study of electron mobility of bis(2-methyl 8-hydroxyquinoline) (triphenyl siloxy) aluminium (SAlq) by transient electroluminescence (EL) is presented. An EL device is fabricated in bilayer, ITO/N,N'-diphenyl-N, N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD)/SAlq/LiF/Al configuration. The temporal evaluation of the EL with respect to the step voltage pulse is characterized by a delay time followed by a fast initial rise, which is followed by a slower rise. The delay time between the applied electrical pulse and the onset of EL is correlated with the carrier mobility (electron in our case). Transient EL studies for SAlq have been carried out at different temperatures and different applied electric fields. The electron mobility in SAlq is found to be field and temperature dependent and calculated to be 6.9 × 10-7 cm2 V-1 s-1 at 2.5 × 106 V cm-1 and 308 K. The EL decays immediately as the voltage is turned off and does not depend on the amplitude of the applied voltage pulse or dc offset.

Self-reported wrist and finger symptoms associated with other physical/mental symptoms and use of computers/mobile phones.

Science.gov (United States)

Korpinen, Leena; Pääkkönen, Rauno; Gobba, Fabriziomaria

2018-03-01

Recently, computer, mobile phone and Internet use has increased. This study aimed to determine the possible relation between self-reported wrist and finger symptoms (aches, pain or numbness) and using computers/mobile phones, and to analyze how the symptoms are specifically associated with utilizing desktop computers, portable computers or mini-computers and mobile phones. A questionnaire was sent to 15,000 working-age Finns (age 18-65). Via a questionnaire, 723 persons reported wrist and finger symptoms often or more with use. Over 80% use mobile phones daily and less than 30% use desktop computers or the Internet daily at leisure, e.g., over 89.8% quite often or often experienced pain, numbness or aches in the neck, and 61.3% had aches in the hips and the lower back. Only 33.7% connected their symptoms to computer use. In the future, the development of new devices and Internet services should incorporate the ergonomics of the hands and wrists.

The Effect of the Presence of an Internet-Connected Mobile Tablet Computer on Physical Activity Behavior in Children.

Science.gov (United States)

Kobak, Mallory S; Lepp, Andrew; Rebold, Michael J; Faulkner, Hannah; Martin, Shannon; Barkley, Jacob E

2018-02-01

Mobile Internet-connected electronic devices provide access to activities that have traditionally been associated with sedentary behavior. Because they are portable, these devices can be utilized in any environment. Therefore, providing children with access to these devices in environments that typically promote physical activity may result in a reduction in physical activity behavior. To assess children's physical and sedentary (ie, sitting) activity with and without the presence of a mobile Internet-connected tablet computer. A total of 20 children [6.7 (1.9) y old] participated in 2 simulated recess conditions in a gymnasium on separate days. During each condition, children had free-choice access physical activity options and a table of sedentary activities for 40 minutes. During 1 session, the iPad was present, and in the other session, it was not. Physical activity was monitored via an accelerometer, and sedentary time was monitored via a stopwatch. Children significantly (P ≤ .03) reduced average physical activity intensity and increased their sedentary behavior with the iPad present [4.4 (4.0) metabolic equivalents/min and 20.9 (12.4) min sitting] versus the condition without the iPad present [5.3 (4.0) metabolic equivalents/min and 13.6 (13.2) min sitting]. Introducing an mobile Internet-connected tablet computer into a gymnasium reduced children's physical activity intensity by 17% and increased sedentary behavior by 54%.

Charge transport in organic molecular semiconductors from first principles: The bandlike hole mobility in a naphthalene crystal

Science.gov (United States)

Lee, Nien-En; Zhou, Jin-Jian; Agapito, Luis A.; Bernardi, Marco

2018-03-01

Predicting charge transport in organic molecular crystals is notoriously challenging. Carrier mobility calculations in organic semiconductors are dominated by quantum chemistry methods based on charge hopping, which are laborious and only moderately accurate. We compute from first principles the electron-phonon scattering and the phonon-limited hole mobility of naphthalene crystal in the framework of ab initio band theory. Our calculations combine GW electronic bandstructures, ab initio electron-phonon scattering, and the Boltzmann transport equation. The calculated hole mobility is in very good agreement with experiment between 100 -300 K , and we can predict its temperature dependence with high accuracy. We show that scattering between intermolecular phonons and holes regulates the mobility, though intramolecular phonons possess the strongest coupling with holes. We revisit the common belief that only rigid molecular motions affect carrier dynamics in organic molecular crystals. Our paper provides a quantitative and rigorous framework to compute charge transport in organic crystals and is a first step toward reconciling band theory and carrier hopping computational methods.

Mobile Workforce, Mobile Technology, Mobile Threats

International Nuclear Information System (INIS)

Garcia, J.

2015-01-01

Mobile technologies' introduction into the world of safeguards business processes such as inspection creates tremendous opportunity for novel approaches and could result in a number of improvements to such processes. Mobile applications are certainly the wave of the future. The success of the application ecosystems has shown that users want full fidelity, highly-usable, simple purpose applications with simple installation, quick responses and, of course, access to network resources at all times. But the counterpart to opportunity is risk, and the widespread adoption of mobile technologies requires a deep understanding of the threats and vulnerabilities inherent in mobile technologies. Modern mobile devices can be characterized as small computers. As such, the threats against computing infrastructure apply to mobile devices. Meanwhile, the attributes of mobile technology that make it such an obvious benefit over traditional computing platforms all have elements of risk: pervasive, always-on networking; diverse ecosystems; lack of centralized control; constantly shifting technological foundations; intense competition among competitors in the marketplace; the scale of the installation base (from millions to billions); and many more. This paper will explore the diverse and massive environment of mobile, the number of attackers and vast opportunities for compromise. The paper will explain how mobile devices prove valuable targets to both advanced and persistent attackers as well as less-skilled casual hackers. Organized crime, national intelligence agencies, corporate espionage are all part of the landscape. (author)

Advances in mobile cloud computing and big data in the 5G era

CERN Document Server

Mastorakis, George; Dobre, Ciprian

2017-01-01

This book reports on the latest advances on the theories, practices, standards and strategies that are related to the modern technology paradigms, the Mobile Cloud computing (MCC) and Big Data, as the pillars and their association with the emerging 5G mobile networks. The book includes 15 rigorously refereed chapters written by leading international researchers, providing the readers with technical and scientific information about various aspects of Big Data and Mobile Cloud Computing, from basic concepts to advanced findings, reporting the state-of-the-art on Big Data management. It demonstrates and discusses methods and practices to improve multi-source Big Data manipulation techniques, as well as the integration of resources availability through the 3As (Anywhere, Anything, Anytime) paradigm, using the 5G access technologies.

Theoretical prediction of high electron mobility in multilayer MoS2 heterostructured with MoSe2

Science.gov (United States)

Ji, Liping; Shi, Juan; Zhang, Z. Y.; Wang, Jun; Zhang, Jiachi; Tao, Chunlan; Cao, Haining

2018-01-01

Two-dimensional (2D) MoS2 has been considered to be one of the most promising semiconducting materials with the potential to be used in novel nanoelectronic devices. High carrier mobility in the semiconductor is necessary to guarantee a low power dissipation and a high switch speed of the corresponding electronic device. Strain engineering in 2D materials acts as an important approach to tailor and design their electronic and carrier transport properties. In this work, strain is introduced to MoS2 through perpendicularly building van der Waals heterostructures MoSe2-MoS2. Our first-principles calculations demonstrate that acoustic-phonon-limited electron mobility can be significantly enhanced in the heterostructures compared with that in pure multilayer MoS2. It is found that the effective electron mass and the deformation potential constant are relatively smaller in the heterostructures, which is responsible for the enhancement in the electron mobility. Overall, the electron mobility in the heterostructures is about 1.5 times or more of that in pure multilayer MoS2 with the same number of layers for the studied structures. These results indicate that MoSe2 is an excellent material to be heterostructured with multilayer MoS2 to improve the charge transport property.

The 3d International Workshop on Computational Electronics

Science.gov (United States)

Goodnick, Stephen M.

1994-09-01

The Third International Workshop on Computational Electronics (IWCE) was held at the Benson Hotel in downtown Portland, Oregon, on May 18, 19, and 20, 1994. The workshop was devoted to a broad range of topics in computational electronics related to the simulation of electronic transport in semiconductors and semiconductor devices, particularly those which use large computational resources. The workshop was supported by the National Science Foundation (NSF), the Office of Naval Research and the Army Research Office, as well as local support from the Oregon Joint Graduate Schools of Engineering and the Oregon Center for Advanced Technology Education. There were over 100 participants in the Portland workshop, of which more than one quarter represented research groups outside of the United States from Austria, Canada, France, Germany, Italy, Japan, Switzerland, and the United Kingdom. There were a total 81 papers presented at the workshop, 9 invited talks, 26 oral presentations and 46 poster presentations. The emphasis of the contributions reflected the interdisciplinary nature of computational electronics with researchers from the Chemistry, Computer Science, Mathematics, Engineering, and Physics communities participating in the workshop.

Influence of 60Co gamma radiation on fluorine plasma treated enhancement-mode high-electron-mobility transistor

International Nuclear Information System (INIS)

Quan Si; Hao Yue; Ma Xiao-Hua; Yu Hui-You

2011-01-01

AlGaN/GaN depletion-mode high-electron-mobility transistor (D-HEMT) and fluorine (F) plasma treated enhancement-mode high-electron-mobility transistor (E-HEMT) are exposed to 60 Co gamma radiation with a dose of 1.6 Mrad (Si). No degradation is observed in the performance of D-HEMT. However, the maximum transconductance of E-HEMT is increased after radiation. The 2DEG density and the mobility are calculated from the results of capacitance-voltage measurement. The electron mobility decreases after fluorine plasma treatment and recovers after radiation. Conductance measurements in a frequency range from 10 kHz to 1 MHz are used to characterize the trapping effects in the devices. A new type of trap is observed in the F plasma treated E-HEMT compared with the D-HEMT, but the density of the trap decreases by radiation. Fitting of G p /ω data yields the trap densities D T = (1 − 3) × 10 12 cm −2 · eV −1 and D T = (0.2 − 0.8) × 10 12 cm −2 · eV −1 before and after radiation, respectively. The time constant is 0.5 ms-6 ms. With F plasma treatment, the trap is introduced by etch damage and degrades the electronic mobility. After 60 Co gamma radiation, the etch damage decreases and the electron mobility is improved. The gamma radiation can recover the etch damage caused by F plasma treatment. (interdisciplinary physics and related areas of science and technology)

The Internet in Connecting Electronics Health Record Mobile Clients

Czech Academy of Sciences Publication Activity Database

Hanzlíček, Petr; Špidlen, Josef; Zvárová, Jana

2002-01-01

Roč. 10, č. 6 (2002), s. 502-503 ISSN 0928-7329. [Mednet 2002. Qualit-e-Health. World Conference on the Internet in Medicine /7./. 04.12.2002-07.12.2002, Amsterdam] Institutional research plan: AV0Z1030915 Keywords : distributed electronic health record * mobile health data access Subject RIV: BD - Theory of Information

A Study on Mobile Learning as a Learning Style in Modern Research Practice

Science.gov (United States)

Joan, D. R. Robert

2013-01-01

Mobile learning is a kind of learning that takes place via a portable handheld electronic device. It also refers to learning via other kinds of mobile devices such as tablet computers, net-books and digital readers. The objective of mobile learning is to provide the learner the ability to assimilate learning anywhere and at anytime. Mobile devices…

Electron mobility in supercritical pentanes as a function of density and temperature

International Nuclear Information System (INIS)

Itoh, Kengo; Nakagawa, Kazumichi; Nishikawa, Masaru

1988-01-01

The excess electron mobility in supercritical n-, iso- and neopentane was measured isothermally as a function of density. The density-normalized mobility μN in all three isomers goes through a minimum at a density below the respective critical densities, and the mobility is quite temperature-dependent in this region, then goes through a minimum. The μN behavior around the minimum in n-pentane is well accounted for by the Cohen-Lekner model with the structure factor S(K) estimated from the speed of sound, while that in iso- and neopentane is not. (author)

Investigating the need for clinicians to use tablet computers with a newly envisioned electronic health record.

Science.gov (United States)

Saleem, Jason J; Savoy, April; Etherton, Gale; Herout, Jennifer

2018-02-01

The Veterans Health Administration (VHA) has deployed a large number of tablet computers in the last several years. However, little is known about how clinicians may use these devices with a newly planned Web-based electronic health record (EHR), as well as other clinical tools. The objective of this study was to understand the types of use that can be expected of tablet computers versus desktops. Semi-structured interviews were conducted with 24 clinicians at a Veterans Health Administration (VHA) Medical Center. An inductive qualitative analysis resulted in findings organized around recurrent themes of: (1) Barriers, (2) Facilitators, (3) Current Use, (4) Anticipated Use, (5) Patient Interaction, and (6) Connection. Our study generated several recommendations for the use of tablet computers with new health information technology tools being developed. Continuous connectivity for the mobile device is essential to avoid interruptions and clinician frustration. Also, making a physical keyboard available as an option for the tablet was a clear desire from the clinicians. Larger tablets (e.g., regular size iPad as compared to an iPad mini) were preferred. Being able to use secure messaging tools with the tablet computer was another consistent finding. Finally, more simplicity is needed for accessing patient data on mobile devices, while balancing the important need for adequate security. Published by Elsevier B.V.

Exploring gender differences on general and specific computer self-efficacy in mobile learning adoption

OpenAIRE

Bao, Yukun; Xiong, Tao; Hu, Zhongyi; Kibelloh, Mboni

2014-01-01

Reasons for contradictory findings regarding the gender moderate effect on computer self-efficacy in the adoption of e-learning/mobile learning are limited. Recognizing the multilevel nature of the computer self-efficacy (CSE), this study attempts to explore gender differences in the adoption of mobile learning, by extending the Technology Acceptance Model (TAM) with general and specific CSE. Data collected from 137 university students were tested against the research model using the structur...

Electron small polarons and their mobility in iron (oxyhydr)oxide nanoparticles

DEFF Research Database (Denmark)

Katz, Jordan E; Zhang, Xiaoyi; Attenkofer, Klaus

2012-01-01

Electron mobility within iron (oxyhydr)oxides enables charge transfer between widely separated surface sites. There is increasing evidence that this internal conduction influences the rates of interfacial reactions and the outcomes of redox-driven phase transformations of environmental interest....... To determine the links between crystal structure and charge-transport efficiency, we used pump-probe spectroscopy to study the dynamics of electrons introduced into iron(III) (oxyhydr)oxide nanoparticles via ultrafast interfacial electron transfer. Using time-resolved x-ray spectroscopy and ab initio...

k-Space imaging of anisotropic 2D electron gas in GaN/GaAlN high-electron-mobility transistor heterostructures

OpenAIRE

Lev, L. L.; Maiboroda, I. O.; Husanu, M. -A.; Grichuk, E. S.; Chumakov, N. K.; Ezubchenko, I. S.; Chernykh, I. A.; Wang, X.; Tobler, B.; Schmitt, T.; Zanaveskin, M. L.; Valeyev, V. G.; Strocov, V. N.

2018-01-01

Nanostructures based on buried interfaces and heterostructures are at the heart of modern semiconductor electronics as well as future devices utilizing spintronics, multiferroics, topological effects and other novel operational principles. Knowledge of electronic structure of these systems resolved in electron momentum k delivers unprecedented insights into their physics. Here, we explore 2D electron gas formed in GaN/AlGaN high-electron-mobility transistor (HEMT) heterostructures with an ult...

Transformational silicon electronics

KAUST Repository

Rojas, Jhonathan Prieto; Sevilla, Galo T.; Ghoneim, Mohamed T.; Inayat, Salman Bin; Ahmed, Sally; Hussain, Aftab M.; Hussain, Muhammad Mustafa

2014-01-01

In today's traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100

78 FR 56737 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

Science.gov (United States)

2013-09-13

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review an... on the Commission's electronic docket (EDIS) at http://edis.usitc.gov . Hearing-impaired persons are...

78 FR 49764 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

Science.gov (United States)

2013-08-15

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review n... for this investigation may be viewed on the Commission's electronic docket (EDIS) at http://edis.usitc...

78 FR 72712 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

Science.gov (United States)

2013-12-03

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review an... this investigation may be viewed on the Commission's electronic docket (EDIS) at http://edis.usitc.gov...

Mobile devices and computing cloud resources allocation for interactive applications

Directory of Open Access Journals (Sweden)

Krawczyk Henryk

2017-06-01

Full Text Available Using mobile devices such as smartphones or iPads for various interactive applications is currently very common. In the case of complex applications, e.g. chess games, the capabilities of these devices are insufficient to run the application in real time. One of the solutions is to use cloud computing. However, there is an optimization problem of mobile device and cloud resources allocation. An iterative heuristic algorithm for application distribution is proposed. The algorithm minimizes the energy cost of application execution with constrained execution time.

An Analog Computer for Electronic Engineering Education

Science.gov (United States)

Fitch, A. L.; Iu, H. H. C.; Lu, D. D. C.

2011-01-01

This paper describes a compact analog computer and proposes its use in electronic engineering teaching laboratories to develop student understanding of applications in analog electronics, electronic components, engineering mathematics, control engineering, safe laboratory and workshop practices, circuit construction, testing, and maintenance. The…

Integrity protection for code-on-demand mobile agents in e-commerce

OpenAIRE

Wang, TH; Guan, SU; Chan, TK

2002-01-01

The mobile agent paradigm has been proposed as a promising solution to facilitate distributed computing over open and heterogeneous networks. Mobility, autonomy, and intelligence are identified as key features of mobile agent systems and enabling characteristics for the next-generation smart electronic commerce on the Internet. However, security-related issues, especially integrity protection in mobile agent technology, still hinder the widespread use of software agents: from the agent’s pers...

Electronic Computer Originated Mail Service

Science.gov (United States)

Seto, Takao

Electronic mail originated by computer is exactly a new communication media which is a product of combining traditional mailing with electrical communication. Experimental service of this type of mailing started in June 10, 1985 at Ministry of Posts and Telecommunications. Its location in various communication media, its comparison with facsimile type electronic mailing, and status quo of electronic mailing in foreign countries are described. Then, this mailing is briefed centering around the system organization and the services. Additional services to be executed in near future are also mentioned.

The Rise of Mobile Technology on the Financial Sector in Zimbabwe

OpenAIRE

Paul Mupfiga; Tafadzwa Padare

2017-01-01

The emergence of technology has revolted the way that the financial industry operates and the increasing use of mobile gadgets has changed the banking system from the traditional brick and mortar building to a virtual system. The sudden rise in use and innovation of smart mobile phones, mobile personal computers, tablets and various other mobile electronic gadgets has resulted in the rise of mobile financial products. Rapid quickening innovative headways are making completely new business sug...

Computer program for afterheat temperature distribution for mobile nuclear power plant

Science.gov (United States)

Parker, W. G.; Vanbibber, L. E.

1972-01-01

ESATA computer program was developed to analyze thermal safety aspects of post-impacted mobile nuclear power plants. Program is written in FORTRAN 4 and designed for IBM 7094/7044 direct coupled system.

Leveraging mobile computing and communication technologies in education

DEFF Research Database (Denmark)

Annan, Nana Kofi

education and technology have evolved in tandem over the past years, this dissertation recognises the lapse that there is, in not being able to effectively leverage technology to improve education delivery by most educators. The study appreciates the enormousness of mobile computing and communication...... technologies in contributing to the development of tertiary education delivery, and has taken keen interest to investigate how the capacities of these technologies can be leveraged and incorporated effectively into the pedagogic framework of tertiary education. The purpose is to research into how...... of the results conducted after rigorous theoretical and empirical research unveiled the following: Mobile technologies can be incorporated into tertiary education if it has a strong theoretical underpinning, which links technology and pedagogy; the technology would not work if the user’s concerns in relation...

Integration of smart wearable mobile devices and cloud computing in South African healthcare

CSIR Research Space (South Africa)

Mvelase, PS

2015-11-01

Full Text Available Integration of Smart Wearable Mobile Devices and Cloud Computing in South African Healthcare Promise MVELASE, Zama DLAMINI, Angeline DLUDLA, Happy SITHOLE Abstract: The acceptance of cloud computing is increasing in a fast pace in distributed...

Mobile and fixed computer use by doctors and nurses on hospital wards

DEFF Research Database (Denmark)

Andersen, Pia; Lindgaard, Anne-Mette; Prgomet, M.

2009-01-01

devices clinicians completed a very low proportion of observed tasks at the bedside. The design of the devices and ward space configurations place limitations on how and where devices are used and on the mobility of clinical work. In such circumstances, clinicians will initiate workarounds to compensate......, computers on wheels (COWs) and tablet PCs-was made. Two types of COWs were available on the wards: generic COWs (laptops mounted on trolleys) and ergonomic COWs (an integrated computer and cart device). Heuristic evaluation of the user interfaces was also carried out. RESULTS: The majority (93...... and doctors were observed performing workarounds, such as transcribing medication orders from the computer to paper. CONCLUSIONS: The choice of device was related to clinical role, nature of the clinical task, degree of mobility required, including where task completion occurs, and device design. Nurses' work...

Density-dependent electron transport and precise modeling of GaN high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Bajaj, Sanyam, E-mail: bajaj.10@osu.edu; Shoron, Omor F.; Park, Pil Sung; Krishnamoorthy, Sriram; Akyol, Fatih; Hung, Ting-Hsiang [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Reza, Shahed; Chumbes, Eduardo M. [Raytheon Integrated Defense Systems, Andover, Massachusetts 01810 (United States); Khurgin, Jacob [Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Rajan, Siddharth [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Department of Material Science and Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

2015-10-12

We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors (HEMTs). Pulsed IV measurements established increasing electron velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 10{sup 7 }cm/s at a low sheet charge density of 7.8 × 10{sup 11 }cm{sup −2}. An optical phonon emission-based electron velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the electron velocity with strong electron-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs.

Density-dependent electron transport and precise modeling of GaN high electron mobility transistors

International Nuclear Information System (INIS)

Bajaj, Sanyam; Shoron, Omor F.; Park, Pil Sung; Krishnamoorthy, Sriram; Akyol, Fatih; Hung, Ting-Hsiang; Reza, Shahed; Chumbes, Eduardo M.; Khurgin, Jacob; Rajan, Siddharth

2015-01-01

We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors (HEMTs). Pulsed IV measurements established increasing electron velocities with decreasing sheet charge densities, resulting in saturation velocity of 1.9 × 10 7  cm/s at a low sheet charge density of 7.8 × 10 11  cm −2 . An optical phonon emission-based electron velocity model for GaN is also presented. It accommodates stimulated longitudinal optical (LO) phonon emission which clamps the electron velocity with strong electron-phonon interaction and long LO phonon lifetime in GaN. A comparison with the measured density-dependent saturation velocity shows that it captures the dependence rather well. Finally, the experimental result is applied in TCAD-based device simulator to predict DC and small signal characteristics of a reported GaN HEMT. Good agreement between the simulated and reported experimental results validated the measurement presented in this report and established accurate modeling of GaN HEMTs

An automated meta-monitoring mobile application and front-end interface for the ATLAS computing model

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Gen; Quadt, Arnulf [II. Physikalisches Institut, Georg-August-Universitaet Goettingen (Germany)

2016-07-01

Efficient administration of computing centres requires advanced tools for the monitoring and front-end interface of the infrastructure. Providing the large-scale distributed systems as a global grid infrastructure, like the Worldwide LHC Computing Grid (WLCG) and ATLAS computing, is offering many existing web pages and information sources indicating the status of the services, systems and user jobs at grid sites. A meta-monitoring mobile application which automatically collects the information could give every administrator a sophisticated and flexible interface of the infrastructure. We describe such a solution; the MadFace mobile application developed at Goettingen. It is a HappyFace compatible mobile application which has a user-friendly interface. It also becomes very feasible to automatically investigate the status and problem from different sources and provides access of the administration roles for non-experts.

Cloud and fog computing in 5G mobile networks emerging advances and applications

CERN Document Server

Markakis, Evangelos; Mavromoustakis, Constandinos X; Pallis, Evangelos

2017-01-01

This book focuses on the challenges and solutions related to cloud and fog computing for 5G mobile networks, and presents novel approaches to the frameworks and schemes that carry out storage, communication, computation and control in the fog/cloud paradigm.

Designing a Mobile Game for Home Computer Users to Protect Against Phishing Attacks

OpenAIRE

Arachchilage, Nalin Asanka Gamagedara; Cole, Melissa

2016-01-01

This research aims to design an educational mobile game for home computer users to prevent from phishing attacks. Phishing is an online identity theft which aims to steal sensitive information such as username, password and online banking details from victims. To prevent this, phishing education needs to be considered. Mobile games could facilitate to embed learning in a natural environment. The paper introduces a mobile game design based on a story which is simplifying and exaggerating real ...

Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

Energy Technology Data Exchange (ETDEWEB)

Fletcher, James H. [University of North Florida; Cox, Philip [University of North Florida; Harrington, William J [University of North Florida; Campbell, Joseph L [University of North Florida

2013-09-03

ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focused on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel

Using computer, mobile and wearable technology enhanced interventions to reduce sedentary behaviour: a systematic review and meta-analysis.

Science.gov (United States)

Stephenson, Aoife; McDonough, Suzanne M; Murphy, Marie H; Nugent, Chris D; Mair, Jacqueline L

2017-08-11

High levels of sedentary behaviour (SB) are associated with negative health consequences. Technology enhanced solutions such as mobile applications, activity monitors, prompting software, texts, emails and websites are being harnessed to reduce SB. The aim of this paper is to evaluate the effectiveness of such technology enhanced interventions aimed at reducing SB in healthy adults and to examine the behaviour change techniques (BCTs) used. Five electronic databases were searched to identify randomised-controlled trials (RCTs), published up to June 2016. Interventions using computer, mobile or wearable technologies to facilitate a reduction in SB, using a measure of sedentary time as an outcome, were eligible for inclusion. Risk of bias was assessed using the Cochrane Collaboration's tool and interventions were coded using the BCT Taxonomy (v1). Meta-analysis of 15/17 RCTs suggested that computer, mobile and wearable technology tools resulted in a mean reduction of -41.28 min per day (min/day) of sitting time (95% CI -60.99, -21.58, I2 = 77%, n = 1402), in favour of the intervention group at end point follow-up. The pooled effects showed mean reductions at short (≤ 3 months), medium (>3 to 6 months), and long-term follow-up (>6 months) of -42.42 min/day, -37.23 min/day and -1.65 min/day, respectively. Overall, 16/17 studies were deemed as having a high or unclear risk of bias, and 1/17 was judged to be at a low risk of bias. A total of 46 BCTs (14 unique) were coded for the computer, mobile and wearable components of the interventions. The most frequently coded were "prompts and cues", "self-monitoring of behaviour", "social support (unspecified)" and "goal setting (behaviour)". Interventions using computer, mobile and wearable technologies can be effective in reducing SB. Effectiveness appeared most prominent in the short-term and lessened over time. A range of BCTs have been implemented in these interventions. Future studies need to improve reporting

Optical phonon scattering on electronic mobility in Al2O3/AlGaN/AlN/GaN heterostructures

Science.gov (United States)

Zhou, X. J.; Qu, Y.; Ban, S. L.; Wang, Z. P.

2017-12-01

Considering the built-in electric fields and the two-mode property of transverse optical phonons in AlGaN material, the electronic eigen-energies and wave functions are obtained by solving Schrödinger equation with the finite difference method. The dispersion relations and potentials of the optical phonons are given by the transfer matrix method. The mobility of the two dimensional electron gas influenced by the optical phonons in Al2O3/AlGaN/AlN/GaN heterostructures is investigated based on the theory of Lei-Ting force balance equation. It is found that the scattering from the half-space phonons is the main factor affecting the electronic mobility, and the influence of the other phonons can be ignored. The results show that the mobility decreases with increasing the thicknesses of Al2O3 and AlN layers, but there is no definite relationship between the mobility and the thickness of AlGaN barrier. The mobility is obviously reduced by increasing Al component in AlGaN crystal to show that the effect of ternary mixed crystals is important. It is also found that the mobility increases first and then decreases as the increment of the fixed charges, but decreases always with increasing temperature. The heterostructures constructed here can be good candidates as metal-oxide-semiconductor high-electron-mobility-transistors since they have higher electronic mobility due to the influence from interface phonons weakened by the AlN interlayer.

A Karaoke System with Real-Time Media Merging and Sharing Functions for a Cloud-Computing-Integrated Mobile Device

Directory of Open Access Journals (Sweden)

Her-Tyan Yeh

2013-01-01

Full Text Available Mobile devices such as personal digital assistants (PDAs, smartphones, and tablets have increased in popularity and are extremely efficient for work-related, social, and entertainment uses. Popular entertainment services have also attracted substantial attention. Thus, relevant industries have exerted considerable efforts in establishing a method by which mobile devices can be used to develop excellent and convenient entertainment services. Because cloud-computing technology is mature and possesses a strong computing processing capacity, integrating this technology into the entertainment service function in mobile devices can reduce the data load on a system and maintain mobile device performances. This study combines cloud computing with a mobile device to design a karaoke system that contains real-time media merging and sharing functions. This system enables users to download music videos (MVs from their mobile device and sing and record their singing by using the device. They can upload the recorded song to the cloud server where it is merged with real-time media. Subsequently, by employing a media streaming technology, users can store their personal MVs in their mobile device or computer and instantaneously share these videos with others on the Internet. Through this process, people can instantly watch shared videos, enjoy the leisure and entertainment effects of mobile devices, and satisfy their desire for singing.

Universality of electron mobility in LaAlO3/SrTiO3 and bulk SrTiO3

Science.gov (United States)

Trier, Felix; Reich, K. V.; Christensen, Dennis Valbjørn; Zhang, Yu; Tuller, Harry L.; Chen, Yunzhong; Shklovskii, B. I.; Pryds, Nini

2017-08-01

Metallic LaAlO3/SrTiO3 (LAO/STO) interfaces attract enormous attention, but the relationship between the electron mobility and the sheet electron density, ns, is poorly understood. Here, we derive a simple expression for the three-dimensional electron density near the interface, n3 D , as a function of ns and find that the mobility for LAO/STO-based interfaces depends on n3 D in the same way as it does for bulk doped STO. It is known that undoped bulk STO is strongly compensated with N ≃5 ×1018 cm-3 background donors and acceptors. In intentionally doped bulk STO with a concentration of electrons n3 DN , the mobility collapses because scattering happens on n3 D intentionally introduced donors. For LAO/STO, the polar catastrophe which provides electrons is not supposed to provide an equal number of random donors and thus the mobility should be larger. The fact that the mobility is still the same implies that for the LAO/STO, the polar catastrophe model should be revisited.

Mobile Customer Relationship Management and Mobile Security

Science.gov (United States)

Sanayei, Ali; Mirzaei, Abas

The purpose of this study is twofold. First, in order to guarantee a coherent discussion about mobile customer relationship management (mCRM), this paper presents a conceptualization of mCRM delineating its unique characteristics because of Among the variety of mobile services, considerable attention has been devoted to mobile marketing and in particular to mobile customer relationship management services. Second, the authors discusses the security risks in mobile computing in different level(user, mobile device, wireless network,...) and finally we focus on enterprise mobile security and it's subgroups with a series of suggestion and solution for improve mobile computing security.

The investigation and implementation of real-time face pose and direction estimation on mobile computing devices

Science.gov (United States)

Fu, Deqian; Gao, Lisheng; Jhang, Seong Tae

2012-04-01

The mobile computing device has many limitations, such as relative small user interface and slow computing speed. Usually, augmented reality requires face pose estimation can be used as a HCI and entertainment tool. As far as the realtime implementation of head pose estimation on relatively resource limited mobile platforms is concerned, it is required to face different constraints while leaving enough face pose estimation accuracy. The proposed face pose estimation method met this objective. Experimental results running on a testing Android mobile device delivered satisfactory performing results in the real-time and accurately.

An analytical model of anisotropic low-field electron mobility in wurtzite indium nitride

International Nuclear Information System (INIS)

Wang, Shulong; Liu, Hongxia; Song, Xin; Guo, Yulong; Yang, Zhaonian

2014-01-01

This paper presents a theoretical analysis of anisotropic transport properties and develops an anisotropic low-field electron analytical mobility model for wurtzite indium nitride (InN). For the different effective masses in the Γ-A and Γ-M directions of the lowest valley, both the transient and steady state transport behaviors of wurtzite InN show different transport characteristics in the two directions. From the relationship between velocity and electric field, the difference is more obvious when the electric field is low in the two directions. To make an accurate description of the anisotropic transport properties under low field, for the first time, we present an analytical model of anisotropic low-field electron mobility in wurtzite InN. The effects of different ionized impurity scattering models on the low-field mobility calculated by Monte Carlo method (Conwell-Weisskopf and Brooks-Herring method) are also considered. (orig.)

[Mobile phone-computer wireless interactive graphics transmission technology and its medical application].

Science.gov (United States)

Huang, Shuo; Liu, Jing

2010-05-01

Application of clinical digital medical imaging has raised many tough issues to tackle, such as data storage, management, and information sharing. Here we investigated a mobile phone based medical image management system which is capable of achieving personal medical imaging information storage, management and comprehensive health information analysis. The technologies related to the management system spanning the wireless transmission technology, the technical capabilities of phone in mobile health care and management of mobile medical database were discussed. Taking medical infrared images transmission between phone and computer as an example, the working principle of the present system was demonstrated.

The Uses and Impacts of Mobile Computing Technology in Hot Spots Policing.

Science.gov (United States)

Koper, Christopher S; Lum, Cynthia; Hibdon, Julie

2015-12-01

Recent technological advances have much potential for improving police performance, but there has been little research testing whether they have made police more effective in reducing crime. To study the uses and crime control impacts of mobile computing technology in the context of geographically focused "hot spots" patrols. An experiment was conducted using 18 crime hot spots in a suburban jurisdiction. Nine of these locations were randomly selected to receive additional patrols over 11 weeks. Researchers studied officers' use of mobile information technology (IT) during the patrols using activity logs and interviews. Nonrandomized subgroup and multivariate analyses were employed to determine if and how the effects of the patrols varied based on these patterns. Officers used mobile computing technology primarily for surveillance and enforcement (e.g., checking automobile license plates and running checks on people during traffic stops and field interviews), and they noted both advantages and disadvantages to its use. Officers did not often use technology for strategic problem-solving and crime prevention. Given sufficient (but modest) dosages, the extra patrols reduced crime at the hot spots, but this effect was smaller in places where officers made greater use of technology. Basic applications of mobile computing may have little if any direct, measurable impact on officers' ability to reduce crime in the field. Greater training and emphasis on strategic uses of IT for problem-solving and crime prevention, and greater attention to its behavioral effects on officers, might enhance its application for crime reduction. © The Author(s) 2016.

Resonance scattering and low-temperature electron mobility in HgTe-based gapless solid solutions

International Nuclear Information System (INIS)

Raikh, M.Eh.; Ehfros, A.L.

1986-01-01

Low-temperature electron mobility in a gapless semiconductor conditioned by electron resonance scattering on neutral acceptors, the levels of which are located in narrow vicinity near the Fermi level, is calculated. Mobility turns to be inverse proportional to density of acceptor states at the Fermi level. If donor concentration is rather high, then presence of a Coulomb gap at the Fermi level in the density of acceptor states conditioned by long-range character of Coulomb interaction should be taken into account for calculation of mobility. The Fermi level is placed in the tail of the acceptor state density at rather low donor concentration, and the Coulomb gap is absent at the Fermi level. A case of high acceptor concentration, when the acceptor states are delocalized at the Fermi level, is also considered

M&E-NetPay: A Micropayment System for Mobile and Electronic Commerce

Directory of Open Access Journals (Sweden)

Xiaodi Huang

2016-08-01

Full Text Available As an increasing number of people purchase goods and services online, micropayment systems are becoming particularly important for mobile and electronic commerce. We have designed and developed such a system called M&E-NetPay (Mobile and Electronic NetPay. With open interoperability and mobility, M&E-NetPay uses web services to connect brokers and vendors, providing secure, flexible and reliable credit services over the Internet. In particular, M&E-NetPay makes use of a secure, inexpensive and debit-based off-line protocol that allows vendors to interact only with customers, after validating coins. The design of the architecture and protocol of M&E-NetPay are presented, together with the implementation of its prototype in ringtone and wallpaper sites. To validate our system, we have conducted its evaluations on performance, usability and heuristics. Furthermore, we compare our system to the CORBA-based (Common Object Request Broker Architecture off-line micro-payment systems. The results have demonstrated that M&E-NetPay outperforms the .NET-based M&E-NetPay system in terms of performance and user satisfaction.

Using the CPU and GPU for real-time video enhancement on a mobile computer

CSIR Research Space (South Africa)

Bachoo, AK

2010-09-01

Full Text Available . In this paper, the current advances in mobile CPU and GPU hardware are used to implement video enhancement algorithms in a new way on a mobile computer. Both the CPU and GPU are used effectively to achieve realtime performance for complex image enhancement...

Internet Use and Access Among Pregnant Women via Computer and Mobile Phone: Implications for Delivery of Perinatal Care.

Science.gov (United States)

Peragallo Urrutia, Rachel; Berger, Alexander A; Ivins, Amber A; Beckham, A Jenna; Thorp, John M; Nicholson, Wanda K

2015-03-30

The use of Internet-based behavioral programs may be an efficient, flexible method to enhance prenatal care and improve pregnancy outcomes. There are few data about access to, and use of, the Internet via computers and mobile phones among pregnant women. We describe pregnant women's access to, and use of, computers, mobile phones, and computer technologies (eg, Internet, blogs, chat rooms) in a southern United States population. We describe the willingness of pregnant women to participate in Internet-supported weight-loss interventions delivered via computers or mobile phones. We conducted a cross-sectional survey among 100 pregnant women at a tertiary referral center ultrasound clinic in the southeast United States. Data were analyzed using Stata version 10 (StataCorp) and R (R Core Team 2013). Means and frequency procedures were used to describe demographic characteristics, access to computers and mobile phones, and use of specific Internet modalities. Chi-square testing was used to determine whether there were differences in technology access and Internet modality use according to age, race/ethnicity, income, or children in the home. The Fisher's exact test was used to describe preferences to participate in Internet-based postpartum weight-loss interventions via computer versus mobile phone. Logistic regression was used to determine demographic characteristics associated with these preferences. The study sample was 61.0% white, 26.0% black, 6.0% Hispanic, and 7.0% Asian with a mean age of 31.0 (SD 5.1). Most participants had access to a computer (89/100, 89.0%) or mobile phone (88/100, 88.0%) for at least 8 hours per week. Access remained high (>74%) across age groups, racial/ethnic groups, income levels, and number of children in the home. Internet/Web (94/100, 94.0%), email (90/100, 90.0%), and Facebook (50/100, 50.0%) were the most commonly used Internet technologies. Women aged less than 30 years were more likely to report use of Twitter and chat rooms

A New Adaptive Checkpointing Strategy for Mobile Computing

Institute of Scientific and Technical Information of China (English)

MENChaoguang; ZUODecheng; YANGXiaozong

2005-01-01

Adaptive checkpointing strategy is an efficient recovery scheme, which is suitable for mobile computing system. However， all existing adaptive checkpointing schemes are not correct to recover system when failure occurs in some special period. In this paper， the issues that will lead to system inconsistency are first discussed and then a new adaptive strategy that can recover system to correct consistent state is proposed. Our algorithm improves system recovery performance because only failure process needs rollback through logging.

Investigating the Determinants and Age and Gender Differences in the Acceptance of Mobile Learning

Science.gov (United States)

Wang, Yi-Shun; Wu, Ming-Cheng; Wang, Hsiu-Yuan

2009-01-01

With the proliferation of mobile computing technology, mobile learning (m-learning) will play a vital role in the rapidly growing electronic learning market. M-learning is the delivery of learning to students anytime and anywhere through the use of wireless Internet and mobile devices. However, acceptance of m-learning by individuals is critical…

High electron mobility recovery in AlGaN/GaN 2DEG channels regrown on etched surfaces

International Nuclear Information System (INIS)

Chan, Silvia H; DenBaars, Steven P; Keller, Stacia; Tahhan, Maher; Li, Haoran; Romanczyk, Brian; Mishra, Umesh K

2016-01-01

This paper reports high two-dimensional electron gas mobility attained from the regrowth of the AlGaN gating layer on ex situ GaN surfaces. To repair etch-damaged GaN surfaces, various pretreatments were conducted via metalorganic chemical vapor deposition, followed by a regrown AlGaN/GaN mobility test structure to evaluate the extent of recovery. The developed treatment process that was shown to significantly improve the electron mobility consisted of a N 2  + NH 3 pre-anneal plus an insertion of a 4 nm or thicker GaN interlayer prior to deposition of the AlGaN gating layer. Using the optimized process, a high electron mobility transistor (HEMT) device was fabricated which exhibited a high mobility of 1450 cm 2 V −1 s −1 (R sh  = 574 ohm/sq) and low dispersion characteristics. The additional inclusion of an in situ Al 2 O 3 dielectric into the regrowth process for MOS-HEMTs still preserved the transport properties near etch-impacted areas. (paper)

Collaborative Research Centre 694 “Integration of electronic components into mobile systems”-Motivation and survey

Science.gov (United States)

Weckenmann, Albert; Schmidt, Lorenz-Peter; Bookjans, Martin

Within the collaborative research centre 694 'Integration of electronic components into mobile systems' intelligent mechatronic systems are explored for application at the place of action. Especially in the automotive sector highest requirements on system safety are combined with an enormous importance of the production for the whole national economy. Therefore the collaborative research centre is led by the vision to integrate electronic components in sensors and actors of mobile systems. About 30 scientists at nine participating academic and non-academic institutions in Erlangen explore mechatronic solutions for the requirements on manufacturing processes, electronic systems and quality management techniques within the car of the future.

Have Computer, Will Not Travel: Meeting Electronically.

Science.gov (United States)

Kurland, Norman D.

1983-01-01

Beginning with two different scenarios depicting a face-to-face conference on the one hand and, on the other, a computer or electronic conference, the author argues the advantages of electronic conferencing and describes some of its uses. (JBM)

Four-dimensional computed tomographic analysis of esophageal mobility during normal respiration

NARCIS (Netherlands)

Dieleman, Edith M. T.; Senan, Suresh; Vincent, Andrew; Lagerwaard, Frank J.; Slotman, Ben J.; van Sörnsen de Koste, John R.

2007-01-01

BACKGROUND: Chemo-radiotherapy for thoracic tumors can result in high-grade radiation esophagitis. Treatment planning to reduce esophageal irradiation requires organ motion to be accounted for. In this study, esophageal mobility was assessed using four-dimensional computed tomography (4DCT). METHODS

Density induced crossover of electron mobilities in fluid C3 hydrocarbons; liquid phase behavior

International Nuclear Information System (INIS)

Gee, N.; Freeman, G.R.

1980-01-01

At n = 2 x 10 20 mol/cm 3 in the saturated vapors, the density normalized mobility (μn) of electrons equalled 2.4 x 10 23 mol/cmVs in cyclopropane, 1.5 x 10 23 in propane and 5.4 x 10 22 in propene. In cyclopropane and propene μn decreased due to quasilocalization at n > 4 x 10 20 mol/cm 3 . In propane quasilocalization occurred at n > 8 x 10 20 mol/cm 3 . The more extensive quasilocalization in cyclopropane caused mobilities to be lower than those in propane at the same density when the densities were greater than 1.3 x 10 21 mol/cm 3 . In propylene, μn remained below those in the other compounds at all gas densities. In the liquid phase the mobilities were affected more by the changes of temperature than by those of density. The mobilities at a given temperature decreased in the order propane > propene > cyclopropane. It is curious that the electron traps are deeper in cyclopropane than in propene. The energies of both thermal and optical excitation of solvated electrons may be expressed by equations of the form E 0 = E(0) - aT over considerable ranges of temperature T. The thermal value of a/E(0) is 1.7 x 10 -3 K -1 in many hydrocarbons, estimated from the mobilities. The equivalent ratio of the optical parameters also equals 1.7 x 10 -3 K -1 in ethers and in ammonia. (author)

Noninvasive coronary angioscopy using electron beam computed tomography and multidetector computed tomography

NARCIS (Netherlands)

van Ooijen, PMA; Nieman, K; de Feyter, PJ; Oudkerk, M

2002-01-01

With the advent of noninvasive coronary imaging techniques like multidetector computed tomography and electron beam computed tomography, new representation methods such as intracoronary visualization. have been introduced. We explore the possibilities of these novel visualization techniques and

Mobile, Cloud, and Big Data Computing: Contributions, Challenges, and New Directions in Telecardiology

OpenAIRE

Hsieh, Jui-Chien; Li, Ai-Hsien; Yang, Chung-Chi

2013-01-01

Many studies have indicated that computing technology can enable off-site cardiologists to read patients’ electrocardiograph (ECG), echocardiography (ECHO), and relevant images via smart phones during pre-hospital, in-hospital, and post-hospital teleconsultation, which not only identifies emergency cases in need of immediate treatment, but also prevents the unnecessary re-hospitalizations. Meanwhile, several studies have combined cloud computing and mobile computing to facilitate better stora...

Tuning the Electronic Properties, Effective Mass and Carrier Mobility of MoS2 Monolayer by Strain Engineering: First-Principle Calculations

Science.gov (United States)

Phuc, Huynh V.; Hieu, Nguyen N.; Hoi, Bui D.; Hieu, Nguyen V.; Thu, Tran V.; Hung, Nguyen M.; Ilyasov, Victor V.; Poklonski, Nikolai A.; Nguyen, Chuong V.

2018-01-01

In this paper, we studied the electronic properties, effective masses, and carrier mobility of monolayer MoS_2 using density functional theory calculations. The carrier mobility was considered by means of ab initio calculations using the Boltzmann transport equation coupled with deformation potential theory. The effects of mechanical biaxial strain on the electronic properties, effective mass, and carrier mobility of monolayer MoS_2 were also investigated. It is demonstrated that the electronic properties, such as band structure and density of state, of monolayer MoS_2 are very sensitive to biaxial strain, leading to a direct-indirect transition in semiconductor monolayer MoS_2. Moreover, we found that the carrier mobility and effective mass can be enhanced significantly by biaxial strain and by lowering temperature. The electron mobility increases over 12 times with a biaxial strain of 10%, while the carrier mobility gradually decreases with increasing temperature. These results are very useful for the future nanotechnology, and they make monolayer MoS_2 a promising candidate for application in nanoelectronic and optoelectronic devices.

Wearable computer for mobile augmented-reality-based controlling of an intelligent robot

Science.gov (United States)

Turunen, Tuukka; Roening, Juha; Ahola, Sami; Pyssysalo, Tino

2000-10-01

An intelligent robot can be utilized to perform tasks that are either hazardous or unpleasant for humans. Such tasks include working in disaster areas or conditions that are, for example, too hot. An intelligent robot can work on its own to some extent, but in some cases the aid of humans will be needed. This requires means for controlling the robot from somewhere else, i.e. teleoperation. Mobile augmented reality can be utilized as a user interface to the environment, as it enhances the user's perception of the situation compared to other interfacing methods and allows the user to perform other tasks while controlling the intelligent robot. Augmented reality is a method that combines virtual objects into the user's perception of the real world. As computer technology evolves, it is possible to build very small devices that have sufficient capabilities for augmented reality applications. We have evaluated the existing wearable computers and mobile augmented reality systems to build a prototype of a future mobile terminal- the CyPhone. A wearable computer with sufficient system resources for applications, wireless communication media with sufficient throughput and enough interfaces for peripherals has been built at the University of Oulu. It is self-sustained in energy, with enough operating time for the applications to be useful, and uses accurate positioning systems.

Multisubband electron mobility in a parabolic quantum well structure under the influence of an applied electric field

International Nuclear Information System (INIS)

Sahoo, N.; Sahu, T.

2014-01-01

We study the multisubband electron mobility in a barrier delta doped Al x Ga 1−x As parabolic quantum well structure under the influence of an applied electric field perpendicular to the interface plane. We consider the alloy fraction x = 0.3 for barriers and vary x from 0.0 to 0.1 for the parabolic well. Electrons diffuse into the well and confine within the triangular like potentials near the interfaces due to Coulomb interaction with ionized donors. The parabolic structure potential, being opposite in nature, partly compensates the Coulomb potential. The external electric field further amends the potential structure leading to an asymmetric potential profile. Accordingly the energy levels, wave functions and occupation of subbands change. We calculate low temperature electron mobility as a function of the electric field and show that when two subbands are occupied, the mobility is mostly dominated by ionised impurity scattering mediated by intersubband effects. As the field increases transition from double subband to single subband occupancy occurs. A sudden enhancement in mobility is obtained due to curtailment of intersubband effects. Thereafter the mobility is governed by both impurity and alloy disorder scatterings. Our analysis of mobility as a function of the electric field for different structural parameters shows interesting results. (semiconductor physics)

University Students Use of Computers and Mobile Devices for Learning and Their Reading Speed on Different Platforms

Science.gov (United States)

Mpofu, Bongeka

2016-01-01

This research was aimed at the investigation of mobile device and computer use at a higher learning institution. The goal was to determine the current use of computers and mobile devices for learning and the students' reading speed on different platforms. The research was contextualised in a sample of students at the University of South Africa.…

Molecular origin of differences in hole and electron mobility in amorphous Alq3--a multiscale simulation study.

Science.gov (United States)

Fuchs, Andreas; Steinbrecher, Thomas; Mommer, Mario S; Nagata, Yuki; Elstner, Marcus; Lennartz, Christian

2012-03-28

In order to determine the molecular origin of the difference in electron and hole mobilities of amorphous thin films of Alq(3) (meridional Alq(3) (tris(8-hydroxyquinoline) aluminium)) we performed multiscale simulations covering quantum mechanics, molecular mechanics and lattice models. The study includes realistic disordered morphologies, polarized site energies to describe diagonal disorder, quantum chemically calculated transfer integrals for the off-diagonal disorder, inner sphere reorganization energies and an approximative scheme for outer sphere reorganization energies. Intermolecular transfer rates were calculated via Marcus-theory and mobilities were simulated via kinetic Monte Carlo simulations and by a Master Equation approach. The difference in electron and hole mobility originates from the different localization of charge density in the radical anion (more delocalized) compared to the radical cation (more confined). This results in higher diagonal disorder for holes and less favourable overlap properties for the hole transfer integrals leading to an overall higher electron mobility.

A computer-controlled conformal radiotherapy system. IV: Electronic chart

International Nuclear Information System (INIS)

Fraass, Benedick A.; McShan, Daniel L.; Matrone, Gwynne M.; Weaver, Tamar A.; Lewis, James D.; Kessler, Marc L.

1995-01-01

Purpose: The design and implementation of a system for electronically tracking relevant plan, prescription, and treatment data for computer-controlled conformal radiation therapy is described. Methods and Materials: The electronic charting system is implemented on a computer cluster coupled by high-speed networks to computer-controlled therapy machines. A methodical approach to the specification and design of an integrated solution has been used in developing the system. The electronic chart system is designed to allow identification and access of patient-specific data including treatment-planning data, treatment prescription information, and charting of doses. An in-house developed database system is used to provide an integrated approach to the database requirements of the design. A hierarchy of databases is used for both centralization and distribution of the treatment data for specific treatment machines. Results: The basic electronic database system has been implemented and has been in use since July 1993. The system has been used to download and manage treatment data on all patients treated on our first fully computer-controlled treatment machine. To date, electronic dose charting functions have not been fully implemented clinically, requiring the continued use of paper charting for dose tracking. Conclusions: The routine clinical application of complex computer-controlled conformal treatment procedures requires the management of large quantities of information for describing and tracking treatments. An integrated and comprehensive approach to this problem has led to a full electronic chart for conformal radiation therapy treatments

Evaluation of electron mobility in InSb quantum wells by means of percentage-impact

International Nuclear Information System (INIS)

Mishima, T. D.; Edirisooriya, M.; Santos, M. B.

2014-01-01

In order to quantitatively analyze the contribution of each scattering factor toward the total carrier mobility, we use a new convenient figure-of-merit, named a percentage impact. The mobility limit due to a scattering factor, which is widely used to summarize a scattering analysis, has its own advantage. However, a mobility limit is not quite appropriate for the above purpose. A comprehensive understanding of the difference in contribution among many scattering factors toward the total carrier mobility can be obtained by evaluating percentage impacts of scattering factors, which can be straightforwardly calculated from their mobility limits and the total mobility. Our percentage impact analysis shows that threading dislocation is one of the dominant scattering factors for the electron transport in InSb quantum wells at room temperature

78 FR 75942 - Certain Mobile Phones and Tablet Computers, and Components Thereof; Commission Determination To...

Science.gov (United States)

2013-12-13

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-847] Certain Mobile Phones and Tablet Computers, and Components Thereof; Commission Determination To Review in Part a Final Initial Determination... Qualcomm Magellan and Odyssey transceiver chips have become a de facto standard in the mobile devices...

Theoretical modeling of electron mobility in superfluid {sup 4}He

Energy Technology Data Exchange (ETDEWEB)

Aitken, Frédéric; Bonifaci, Nelly [G2ELab-GreEn-ER, Equipe MDE, 21 Avenue des Martyrs, CS 90624, 38031 Grenoble Cedex 1 (France); Haeften, Klaus von [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Eloranta, Jussi, E-mail: Jussi.Eloranta@csun.edu [Department of Chemistry and Biochemistry, California State University at Northridge, 18111 Nordhoff St., Northridge, California 91330 (United States)

2016-07-28

The Orsay-Trento bosonic density functional theory model is extended to include dissipation due to the viscous response of superfluid {sup 4}He present at finite temperatures. The viscous functional is derived from the Navier-Stokes equation by using the Madelung transformation and includes the contribution of interfacial viscous response present at the gas-liquid boundaries. This contribution was obtained by calibrating the model against the experimentally determined electron mobilities from 1.2 K to 2.1 K along the saturated vapor pressure line, where the viscous response is dominated by thermal rotons. The temperature dependence of ion mobility was calculated for several different solvation cavity sizes and the data are rationalized in the context of roton scattering and Stokes limited mobility models. Results are compared to the experimentally observed “exotic ion” data, which provides estimates for the corresponding bubble sizes in the liquid. Possible sources of such ions are briefly discussed.

Internet Use and Access Among Pregnant Women via Computer and Mobile Phone: Implications for Delivery of Perinatal Care

Science.gov (United States)

Peragallo Urrutia, Rachel; Berger, Alexander A; Ivins, Amber A; Beckham, A Jenna; Thorp Jr, John M

2015-01-01

Background The use of Internet-based behavioral programs may be an efficient, flexible method to enhance prenatal care and improve pregnancy outcomes. There are few data about access to, and use of, the Internet via computers and mobile phones among pregnant women. Objective We describe pregnant women’s access to, and use of, computers, mobile phones, and computer technologies (eg, Internet, blogs, chat rooms) in a southern United States population. We describe the willingness of pregnant women to participate in Internet-supported weight-loss interventions delivered via computers or mobile phones. Methods We conducted a cross-sectional survey among 100 pregnant women at a tertiary referral center ultrasound clinic in the southeast United States. Data were analyzed using Stata version 10 (StataCorp) and R (R Core Team 2013). Means and frequency procedures were used to describe demographic characteristics, access to computers and mobile phones, and use of specific Internet modalities. Chi-square testing was used to determine whether there were differences in technology access and Internet modality use according to age, race/ethnicity, income, or children in the home. The Fisher’s exact test was used to describe preferences to participate in Internet-based postpartum weight-loss interventions via computer versus mobile phone. Logistic regression was used to determine demographic characteristics associated with these preferences. Results The study sample was 61.0% white, 26.0% black, 6.0% Hispanic, and 7.0% Asian with a mean age of 31.0 (SD 5.1). Most participants had access to a computer (89/100, 89.0%) or mobile phone (88/100, 88.0%) for at least 8 hours per week. Access remained high (>74%) across age groups, racial/ethnic groups, income levels, and number of children in the home. Internet/Web (94/100, 94.0%), email (90/100, 90.0%), and Facebook (50/100, 50.0%) were the most commonly used Internet technologies. Women aged less than 30 years were more likely to

Lifelong mobile learning: Increasing accessibility and flexibility with tablet computers and ebooks

OpenAIRE

Kalz, Marco

2011-01-01

Kalz, M. (2011, 1 September). Lifelong mobile learning: Increasing accessibility and flexibility with tablet computers and ebooks. Presentation provided during the opening ceremony of the iPad pilot for schakelzone rechten, Utrecht, The Netherlands.

Computational Nanotechnology Molecular Electronics, Materials and Machines

Science.gov (United States)

Srivastava, Deepak; Biegel, Bryan A. (Technical Monitor)

2002-01-01

This presentation covers research being performed on computational nanotechnology, carbon nanotubes and fullerenes at the NASA Ames Research Center. Topics cover include: nanomechanics of nanomaterials, nanotubes and composite materials, molecular electronics with nanotube junctions, kinky chemistry, and nanotechnology for solid-state quantum computers using fullerenes.

Computer conferencing: the "nurse" in the "Electronic School District".

Science.gov (United States)

Billings, D M; Phillips, A

1991-01-01

As computer-based instructional technologies become increasingly available, they offer new mechanisms for health educators to provide health instruction. This article describes a pilot project in which nurses established a computer conference to provide health instruction to high school students participating in an electronic link of high schools. The article discusses computer conferencing, the "Electronic School District," the design of the nursing conference, and the role of the nurse in distributed health education.

Multidimensional control using a mobile-phone based brain-muscle-computer interface.

Science.gov (United States)

Vernon, Scott; Joshi, Sanjay S

2011-01-01

Many well-known brain-computer interfaces measure signals at the brain, and then rely on the brain's ability to learn via operant conditioning in order to control objects in the environment. In our lab, we have been developing brain-muscle-computer interfaces, which measure signals at a single muscle and then rely on the brain's ability to learn neuromuscular skills via operant conditioning. Here, we report a new mobile-phone based brain-muscle-computer interface prototype for severely paralyzed persons, based on previous results from our group showing that humans may actively create specified power levels in two separate frequency bands of a single sEMG signal. Electromyographic activity on the surface of a single face muscle (Auricularis superior) is recorded with a standard electrode. This analog electrical signal is imported into an Android-based mobile phone. User-modulated power in two separate frequency band serves as two separate and simultaneous control channels for machine control. After signal processing, the Android phone sends commands to external devices via Bluetooth. Users are trained to use the device via biofeedback, with simple cursor-to-target activities on the phone screen.

Computational methods of electron/photon transport

International Nuclear Information System (INIS)

Mack, J.M.

1983-01-01

A review of computational methods simulating the non-plasma transport of electrons and their attendant cascades is presented. Remarks are mainly restricted to linearized formalisms at electron energies above 1 keV. The effectiveness of various metods is discussed including moments, point-kernel, invariant imbedding, discrete-ordinates, and Monte Carlo. Future research directions and the potential impact on various aspects of science and engineering are indicated

A new mobile ubiquitous computing application to control obesity: SapoFit.

Science.gov (United States)

Rodrigues, Joel J P C; Lopes, Ivo M C; Silva, Bruno M C; Torre, Isabel de La

2013-01-01

The objective of this work was the proposal, design, construction and validation of a mobile health system for dietetic monitoring and assessment, called SapoFit. This application may be personalized to keep a daily personal health record of an individual's food intake and daily exercise and to share this with a social network. The initiative is a partnership with SAPO - Portugal Telecom. SapoFit uses Web services architecture, a relatively new model for distributed computing and application integration. SapoFit runs on a range of mobile platforms, and it has been implemented successfully in a range of mobile devices and has been evaluated by over 100 users. Most users strongly agree that SapoFit has an attractive design, the environment is user-friendly and intuitive, and the navigation options are clear.

The use of mobile learning application to the fundament of digital electronics course

Science.gov (United States)

Rakhmawati, L.; Firdha, A.

2018-01-01

A new trend in e-learning is known as Mobile Learning. Learning through mobile phones have become part of the educative process. Thus, the purposes of this study are to develop a mobile application for the Fundament of Digital Electronics course that consists of number systems operation, logic gates, and Boolean Algebra, and to assess the readiness, perceptions, and effectiveness of students in the use of mobile devices for learning in the classroom. This research uses Research and Development (R&D) method. The design used in this research, by doing treatment in one class and observing by using Android-based mobile application instructional media. The result obtained from this research shows that the test has 80 % validity aspect, 82 % of the user from senior high school students gives a positive response in using the application of mobile learning, and based on the result of post-test, 90, 90% students passed the exam. At last, it can be concluded that the use of the mobile learning application makes the learning process more effective when it is used in the teaching-learning process.

Effect of temperature and pressure on excess electron mobility in n-hexane, 2,2,4-trimethylpentane, and tetramethylsilane

International Nuclear Information System (INIS)

Munoz, R.C.; Holroyd, R.A.

1986-01-01

Measurements of excess electron mobility are reported for liquid n-hexane, 2,2,4-trimethylpentane, and tetramethylsilane for pressures from 1 to 2500 bar and for temperatures from 18 to 120 0 C. For tetramethylsilane, a liquid that exhibits a high electron mobility, the mobility at constant density is proportional to T/sup -0.9/ between 25 and 100 0 C. The results are compared with the Basak--Cohen deformation potential theory. For n-hexane, where the mobility is low, Arrhenius behavior is observed. The isochoric activation energy increases with density. The results in this case are consistent with both the two-state and hopping models. In 2,2,4-trimethylpentane the mobility increases with increasing pressure at room temperature and decreases at high temperature. At 2500 bar and at intermediate temperatures (70--80 0 C) the mobility is approximately constant

Fabrication of enhancement-mode AlGaN/GaN high electron mobility transistors using double plasma treatment

Energy Technology Data Exchange (ETDEWEB)

Lim, Jong-Won, E-mail: jwlim@etri.re.kr [Photonic/Wireless Convergence Components Dept., IT Materials and Components Lab., Electronics and Telecommunications Research Institute, Daejeon 305-700 (Korea, Republic of); Ahn, Ho-Kyun; Kim, Seong-il; Kang, Dong-Min; Lee, Jong-Min; Min, Byoung-Gue; Lee, Sang-Heung; Yoon, Hyung-Sup; Ju, Chull-Won; Kim, Haecheon; Mun, Jae-Kyoung; Nam, Eun-Soo [Photonic/Wireless Convergence Components Dept., IT Materials and Components Lab., Electronics and Telecommunications Research Institute, Daejeon 305-700 (Korea, Republic of); Park, Hyung-Moo [Photonic/Wireless Convergence Components Dept., IT Materials and Components Lab., Electronics and Telecommunications Research Institute, Daejeon 305-700 (Korea, Republic of); Division of Electronics and Electrical Engineering, Dongguk University, Seoul (Korea, Republic of)

2013-11-29

We report the fabrication and DC and microwave characteristics of 0.5 μm AlGaN/GaN high electron mobility transistors using double plasma treatment process. Silicon nitride layers 700 and 150 Å thick were deposited by plasma-enhanced chemical vapor deposition at 260 °C to protect the device and to define the gate footprint. The double plasma process was carried out by two different etching techniques to obtain enhancement-mode AlGaN/GaN high electron mobility transistors with 0.5 μm gate lengths. The enhancement-mode AlGaN/GaN high electron mobility transistor was prepared in parallel to the depletion-mode AlGaN/GaN high electron mobility transistor device on one wafer. Completed double plasma treated 0.5 μm AlGaN/GaN high electron mobility transistor devices fabricated by dry etching exhibited a peak transconductance, gm, of 330 mS/mm, a breakdown voltage of 115 V, a current-gain cutoff frequency (f{sub T}) of 18 GHz, and a maximum oscillation frequency (f{sub max}) of 66 GHz. - Highlights: • The double plasma process was carried out by two different etching techniques. • Double plasma treated device exhibited a transconductance of 330 mS/mm. • Completed 0.5 μm gate device exhibited a current-gain cutoff frequency of 18 GHz. • The off-state breakdown voltage of 115 V for 0.5 μm gate device was obtained. • Continuous-wave output power density of 4.3 W/mm was obtained at 2.4 GHz.

Fabrication of enhancement-mode AlGaN/GaN high electron mobility transistors using double plasma treatment

International Nuclear Information System (INIS)

Lim, Jong-Won; Ahn, Ho-Kyun; Kim, Seong-il; Kang, Dong-Min; Lee, Jong-Min; Min, Byoung-Gue; Lee, Sang-Heung; Yoon, Hyung-Sup; Ju, Chull-Won; Kim, Haecheon; Mun, Jae-Kyoung; Nam, Eun-Soo; Park, Hyung-Moo

2013-01-01

We report the fabrication and DC and microwave characteristics of 0.5 μm AlGaN/GaN high electron mobility transistors using double plasma treatment process. Silicon nitride layers 700 and 150 Å thick were deposited by plasma-enhanced chemical vapor deposition at 260 °C to protect the device and to define the gate footprint. The double plasma process was carried out by two different etching techniques to obtain enhancement-mode AlGaN/GaN high electron mobility transistors with 0.5 μm gate lengths. The enhancement-mode AlGaN/GaN high electron mobility transistor was prepared in parallel to the depletion-mode AlGaN/GaN high electron mobility transistor device on one wafer. Completed double plasma treated 0.5 μm AlGaN/GaN high electron mobility transistor devices fabricated by dry etching exhibited a peak transconductance, gm, of 330 mS/mm, a breakdown voltage of 115 V, a current-gain cutoff frequency (f T ) of 18 GHz, and a maximum oscillation frequency (f max ) of 66 GHz. - Highlights: • The double plasma process was carried out by two different etching techniques. • Double plasma treated device exhibited a transconductance of 330 mS/mm. • Completed 0.5 μm gate device exhibited a current-gain cutoff frequency of 18 GHz. • The off-state breakdown voltage of 115 V for 0.5 μm gate device was obtained. • Continuous-wave output power density of 4.3 W/mm was obtained at 2.4 GHz

Personal computer versus personal computer/mobile device combination users' preclinical laboratory e-learning activity.

Science.gov (United States)

Kon, Haruka; Kobayashi, Hiroshi; Sakurai, Naoki; Watanabe, Kiyoshi; Yamaga, Yoshiro; Ono, Takahiro

2017-11-01

The aim of the present study was to clarify differences between personal computer (PC)/mobile device combination and PC-only user patterns. We analyzed access frequency and time spent on a complete denture preclinical website in order to maximize website effectiveness. Fourth-year undergraduate students (N=41) in the preclinical complete denture laboratory course were invited to participate in this survey during the final week of the course to track login data. Students accessed video demonstrations and quizzes via our e-learning site/course program, and were instructed to view online demonstrations before classes. When the course concluded, participating students filled out a questionnaire about the program, their opinions, and devices they had used to access the site. Combination user access was significantly more frequent than PC-only during supplementary learning time, indicating that students with mobile devices studied during lunch breaks and before morning classes. Most students had favorable opinions of the e-learning site, but a few combination users commented that some videos were too long and that descriptive answers were difficult on smartphones. These results imply that mobile devices' increased accessibility encouraged learning by enabling more efficient time use between classes. They also suggest that e-learning system improvements should cater to mobile device users by reducing video length and including more short-answer questions. © 2016 John Wiley & Sons Australia, Ltd.

Wireless Technologies, Ubiquitous Computing and Mobile Health: Application to Drug Abuse Treatment and Compliance with HIV Therapies.

Science.gov (United States)

Boyer, Edward W; Smelson, David; Fletcher, Richard; Ziedonis, Douglas; Picard, Rosalind W

2010-06-01

Beneficial advances in the treatment of substance abuse and compliance with medical therapies, including HAART, are possible with new mobile technologies related to personal physiological sensing and computational methods. When incorporated into mobile platforms that allow for ubiquitous computing, these technologies have great potential for extending the reach of behavioral interventions from clinical settings where they are learned into natural environments.

Strain engineering on electronic structure and carrier mobility in monolayer GeP3

Science.gov (United States)

Zeng, Bowen; Long, Mengqiu; Zhang, Xiaojiao; Dong, Yulan; Li, Mingjun; Yi, Yougen; Duan, Haiming

2018-06-01

Using density functional theory coupled with the Boltzmann transport equation with relaxation time approximation, we have studied the strain effect on the electronic structure and carrier mobility of two-dimensional monolayer GeP3. We find that the energies of valence band maximum and conduction band minimum are nearly linearly shifted with a biaxial strain in the range of  ‑4% to 6%, and the band structure experiences a remarkable transition from semiconductor to metal with the appropriate compression (‑5% strain). Under biaxial strain, the mobility of the electron and hole in monolayer GeP3 reduces and increases by more than one order of magnitude, respectively. It is suggested that it is possible to perform successive transitions from an n-type semiconductor (‑4% strain) to a good performance p-semiconductor (+6% strain) by applying strain in monolayer GeP3, which is potentially useful for flexible electronics and nanosized mechanical sensors.

First steps in teaching computational thinking through mobile technology and robotics

Directory of Open Access Journals (Sweden)

Titipan Phetsrikran

2017-07-01

Full Text Available rogramming, or computational thinking, is becoming recognized as a skill that should be taught in primary and secondary schools. One technique for teaching programming is to use robotics, but usually this requires students to program via a PC. The purpose of this study is to investigate the potential for using an iPad application and robot that enables children to learn programming skills. This paper describes an application containing puzzles that involve creating a program to guide the physical robot from a start point to a goal. The application sends commands and controls the robots via Bluetooth and runs on the iPad with iOS. An initial experiment performed in a high school in Thailand explores how mobile technology and educational robotics can be applied to computational thinking in schools. The findings showed that the use of mobile technology opens up alternative styles of interaction in the classroom with potential for highly collaborative activities and greater focus on the learning domain.

Two-Dimensional Modeling of Aluminum Gallium Nitride/Gallium Nitride High Electron Mobility Transistor

National Research Council Canada - National Science Library

Holmes, Kenneth

2002-01-01

Gallium Nitride (GaN) High Electron Mobility Transistors (HEMT's) are microwave power devices that have the performance characteristics to improve the capabilities of current and future Navy radar and communication systems...

National electronic medical records integration on cloud computing system.

Science.gov (United States)

Mirza, Hebah; El-Masri, Samir

2013-01-01

Few Healthcare providers have an advanced level of Electronic Medical Record (EMR) adoption. Others have a low level and most have no EMR at all. Cloud computing technology is a new emerging technology that has been used in other industry and showed a great success. Despite the great features of Cloud computing, they haven't been utilized fairly yet in healthcare industry. This study presents an innovative Healthcare Cloud Computing system for Integrating Electronic Health Record (EHR). The proposed Cloud system applies the Cloud Computing technology on EHR system, to present a comprehensive EHR integrated environment.

Electric field dependence of the electron mobility in bulk wurtzite ZnO

Indian Academy of Sciences (India)

ZnO) material is studied. The low-field electron mobility is calculated as a function of doping concentration and lattice temperature. The results show that above nearly 50 K the electrical conduction is governed by activation through the bulk ...

The Improvement and Performance of Mobile Environment Using Both Cloud and Text Computing

OpenAIRE

S.Saravana Kumar; J.Lakshmi Priya; P.Hannah Jennifer; N.Jeff Monica; Fathima

2013-01-01

In this research paper presents an design model for file sharing system for ubiquitos mobile devices using both cloud and text computing. File s haring is one of the rationales for computer networks with increasing demand for file sharing ap plications and technologies in small and large enterprise networks and on the Internet. File transfer is an important process in any form of computing as we need to really share the data ac ross. ...

Trends of Mobile Learning in Computing Education from 2006 to 2014: A Systematic Review of Research Publications

Science.gov (United States)

Anohah, Ebenezer; Oyelere, Solomon Sunday; Suhonen, Jarkko

2017-01-01

The majority of the existing research regarding mobile learning in computing education has primarily focused on studying the effectiveness of, and in some cases reporting about, implemented mobile learning solutions. However, it is equally important to explore development and application perspectives on the integration of mobile learning into…

AlGaN/GaN High Electron Mobility Transistors with Multi-MgxNy/GaN Buffer

OpenAIRE

Chang, P. C.; Lee, K. H.; Wang, Z. H.; Chang, S. J.

2014-01-01

We report the fabrication of AlGaN/GaN high electron mobility transistors with multi-MgxNy/GaN buffer. Compared with conventional HEMT devices with a low-temperature GaN buffer, smaller gate and source-drain leakage current could be achieved with this new buffer design. Consequently, the electron mobility was larger for the proposed device due to the reduction of defect density and the corresponding improvement of crystalline quality as result of using the multi-MgxNy/GaN buffer.

The effect of charged quantum dots on the mobility of a two-dimensional electron gas: How important is the Coulomb scattering?

International Nuclear Information System (INIS)

Kurzmann, A.; Beckel, A.; Lorke, A.; Geller, M.; Ludwig, A.; Wieck, A. D.

2015-01-01

We have investigated the influence of a layer of charged self-assembled quantum dots (QDs) on the mobility of a nearby two-dimensional electron gas (2DEG). Time-resolved transconductance spectroscopy was used to separate the two contributions of the change in mobility, which are: (i) The electrons in the QDs act as Coulomb scatterers for the electrons in the 2DEG. (ii) The screening ability and, hence, the mobility of the 2DEG decreases when the charge carrier density is reduced by the charged QDs, i.e., the mobility itself depends on the charge carrier concentration. Surprisingly, we find a negligible influence of the Coulomb scattering on the mobility for a 2DEG, separated by a 30 nm tunneling barrier to the layer of QDs. This means that the mobility change is completely caused by depletion, i.e., reduction of the charge carrier density in the 2DEG, which indirectly influences the mobility

Density dependence of electron mobility in the accumulation mode for fully depleted SOI films

Energy Technology Data Exchange (ETDEWEB)

Naumova, O. V., E-mail: naumova@isp.nsc.ru; Zaitseva, E. G.; Fomin, B. I.; Ilnitsky, M. A.; Popov, V. P. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2015-10-15

The electron mobility µ{sub eff} in the accumulation mode is investigated for undepleted and fully depleted double-gate n{sup +}–n–n{sup +} silicon-on-insulator (SOI) metal–oxide–semiconductor field-effect transistors (MOSFET). To determine the range of possible values of the mobility and the dominant scattering mechanisms in thin-film structures, it is proposed that the field dependence of the mobility µ{sub eff} be replaced with the dependence on the density N{sub e} of induced charge carriers. It is shown that the dependences µ{sub eff}(N{sub e}) can be approximated by the power functions µ{sub eff}(N{sub e}) ∝ N{sub e}{sup -n}, where the exponent n is determined by the chargecarrier scattering mechanism as in the mobility field dependence. The values of the exponent n in the dependences µ{sub eff}(N{sub e}) are determined when the SOI-film mode near one of its surfaces varies from inversion to accumulation. The obtained results are explained from the viewpoint of the electron-density redistribution over the SOI-film thickness and changes in the scattering mechanisms.

Intraoperative radiation therapy using mobile electron linear accelerators: Report of AAPM Radiation Therapy Committee Task Group No. 72

International Nuclear Information System (INIS)

Sam Beddar, A.; Biggs, Peter J.; Chang Sha; Ezzell, Gary A.; Faddegon, Bruce A.; Hensley, Frank W.; Mills, Michael D.

2006-01-01

Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems

Electronic Payments using Mobile Communication Devices

NARCIS (Netherlands)

Waaij, B.D. van der; Siljee, B.I.J.; Broekhuijsen, B.J.; Ponsioen, C.; Maas, A.; Aten, R.M.; Hoepman, J.H.; Loon, J.H. van; Smit, M.

2009-01-01

A method of making a payment uses a first mobile communication device (1) and a second mobile communication device (2), each mobile communication device being provided with a respective near field communication unit (11, 21) and at least one of the mobile communication devices being provided with an

Method of mobile robot indoor navigation by artificial landmarks with use of computer vision

Science.gov (United States)

Glibin, E. S.; Shevtsov, A. A.; Enik, O. A.

2018-05-01

The article describes an algorithm of the mobile robot indoor navigation based on the use of visual odometry. The results of the experiment identifying calculation errors in the distance traveled on a slip are presented. It is shown that the use of computer vision allows one to correct erroneous coordinates of the robot with the help of artificial landmarks. The control system utilizing the proposed method has been realized on the basis of Arduino Mego 2560 controller and a single-board computer Raspberry Pi 3. The results of the experiment on the mobile robot navigation with the use of this control system are presented.

Study on the application of mobile internet cloud computing platform

Science.gov (United States)

Gong, Songchun; Fu, Songyin; Chen, Zheng

2012-04-01

The innovative development of computer technology promotes the application of the cloud computing platform, which actually is the substitution and exchange of a sort of resource service models and meets the needs of users on the utilization of different resources after changes and adjustments of multiple aspects. "Cloud computing" owns advantages in many aspects which not merely reduce the difficulties to apply the operating system and also make it easy for users to search, acquire and process the resources. In accordance with this point, the author takes the management of digital libraries as the research focus in this paper, and analyzes the key technologies of the mobile internet cloud computing platform in the operation process. The popularization and promotion of computer technology drive people to create the digital library models, and its core idea is to strengthen the optimal management of the library resource information through computers and construct an inquiry and search platform with high performance, allowing the users to access to the necessary information resources at any time. However, the cloud computing is able to promote the computations within the computers to distribute in a large number of distributed computers, and hence implement the connection service of multiple computers. The digital libraries, as a typical representative of the applications of the cloud computing, can be used to carry out an analysis on the key technologies of the cloud computing.

High mobility 2D electron gas in CdTe/CdMgTe heterostructures

International Nuclear Information System (INIS)

Karczewski, G.; Jaroszynski, J.; Kurowski, M.; Barcz, A.; Wojtowicz, T.; Kossut, J.

1997-01-01

We report on iodine doping of molecular beam epitaxy (MBE)-grown Cd(Mn)Te quasi-bulk films and modulation-doped CdTe/Cd 1-y Mg y Te two-dimensional (2D) single quantum well structures. Modulation doping with iodine of CdTe/Cd 1-y Mg y Te structures resulted in fabrication of a 2D electron gas with mobility exceeding 10 5 cm 2 /(Vs). This is the highest mobility reported in wide-gap II-VI materials

MeReg: Managing Energy-SLA Tradeoff for Green Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Rahul Yadav

2017-01-01

Full Text Available Mobile cloud computing (MCC provides various cloud computing services to mobile users. The rapid growth of MCC users requires large-scale MCC data centers to provide them with data processing and storage services. The growth of these data centers directly impacts electrical energy consumption, which affects businesses as well as the environment through carbon dioxide (CO2 emissions. Moreover, large amount of energy is wasted to maintain the servers running during low workload. To reduce the energy consumption of mobile cloud data centers, energy-aware host overload detection algorithm and virtual machines (VMs selection algorithms for VM consolidation are required during detected host underload and overload. After allocating resources to all VMs, underloaded hosts are required to assume energy-saving mode in order to minimize power consumption. To address this issue, we proposed an adaptive heuristics energy-aware algorithm, which creates an upper CPU utilization threshold using recent CPU utilization history to detect overloaded hosts and dynamic VM selection algorithms to consolidate the VMs from overloaded or underloaded host. The goal is to minimize total energy consumption and maximize Quality of Service, including the reduction of service level agreement (SLA violations. CloudSim simulator is used to validate the algorithm and simulations are conducted on real workload traces in 10 different days, as provided by PlanetLab.

DEVELOPING OF ELECTRONIC TEACHING MATERIAL BASED ON MOBILE LEARNING IN THE WAVE SUBJECTS

Directory of Open Access Journals (Sweden)

D. H. Rif’ati

2015-07-01

Full Text Available In the advanced and modern era, technological sophistication led to learning which initially runs, in which teachers and students meet each other and communicate in the classroom, can be implemented through of information technology. Along with the development of information, where books and teachers who initially as a primary source of learning, are now beginning to experience growth from the internet. Mobile learning defined as mobile devices that are used in the learning process. The wave course is one of subject that must be taken by students of physics education in the third semester. This course emphasizes the concepts of wave were reviewed mathematically and the phenomenon that occurs in everyday life. Mobile learning developed in this study in the form of electronic teaching materials on subjects of waves. The aim of this study was to develop electronic teaching material in the form of mobile learning. The sample of this study is 80 students in the third semester students who are taking waves courses. The results show that mobile learning that has been developed has score 3.8 and included valid criteria. Pada era yang serba maju dan modern, kecanggihan teknologi menyebabkan pembelajaran yang awalnya berjalan satu arah, dimana guru dan siswa saling bertemu dan berkomunikasi di dalam kelas, dapat dilaksanakan melalui bantuan teknologi.informasi. Seiring dengan perkembangan informasi, buku dan guru yang awalnya sebagai sumber belajar utama, saat ini sudah mulai mengalami perkembangan dimana sumber belajar yang berasal dari internet sudah mulai sering dimanfaatkan dalam proses pembelajaran. Mobile larning didefinisikan sebagai perangkat mobile yang dipergunakan dalam proses belajar mengajar. Mata kuliah gelombang sendiri merupakan salah satu mata kuliah yang wajib ditempuh oleh mahasiswa program studi pendidikan fisika semester 3. Mata kuliah ini menekankan pada konsep gelombang yang ditinjau secara matematis dan fenomenanya yang terjadi

AlGaN/GaN High Electron Mobility Transistors with Multi-MgxNy/GaN Buffer

Directory of Open Access Journals (Sweden)

P. C. Chang

2014-01-01

Full Text Available We report the fabrication of AlGaN/GaN high electron mobility transistors with multi-MgxNy/GaN buffer. Compared with conventional HEMT devices with a low-temperature GaN buffer, smaller gate and source-drain leakage current could be achieved with this new buffer design. Consequently, the electron mobility was larger for the proposed device due to the reduction of defect density and the corresponding improvement of crystalline quality as result of using the multi-MgxNy/GaN buffer.

A computer code package for electron transport Monte Carlo simulation

International Nuclear Information System (INIS)

Popescu, Lucretiu M.

1999-01-01

A computer code package was developed for solving various electron transport problems by Monte Carlo simulation. It is based on condensed history Monte Carlo algorithm. In order to get reliable results over wide ranges of electron energies and target atomic numbers, specific techniques of electron transport were implemented such as: Moliere multiscatter angular distributions, Blunck-Leisegang multiscatter energy distribution, sampling of electron-electron and Bremsstrahlung individual interactions. Path-length and lateral displacement corrections algorithms and the module for computing collision, radiative and total restricted stopping powers and ranges of electrons are also included. Comparisons of simulation results with experimental measurements are finally presented. (author)

Artificial and Computational Intelligence for Games on Mobile Platforms

OpenAIRE

Congdon, Clare Bates; Hingston, Philip; Kendall, Graham

2013-01-01

In this chapter, we consider the possibilities of creating new and innovative games that are targeted for mobile devices, such as smart phones and tablets, and that showcase AI (Artificial Intelligence) and CI (Computational Intelligence) approaches. Such games might take advantage of the sensors and facilities that are not available on other platforms, or might simply rely on the "app culture" to facilitate getting the games into users' hands. While these games might be profitable in themsel...

The influence of surfaces on the transient terahertz conductivity and electron mobility of GaAs nanowires

International Nuclear Information System (INIS)

Joyce, Hannah J; Baig, Sarwat A; Parkinson, Patrick; Davies, Christopher L; Boland, Jessica L; Herz, Laura M; Johnston, Michael B; Tan, H Hoe; Jagadish, Chennupati

2017-01-01

Bare unpassivated GaAs nanowires feature relatively high electron mobilities (400–2100 cm 2 V −1 s −1 ) and ultrashort charge carrier lifetimes (1–5 ps) at room temperature. These two properties are highly desirable for high speed optoelectronic devices, including photoreceivers, modulators and switches operating at microwave and terahertz frequencies. When engineering these GaAs nanowire-based devices, it is important to have a quantitative understanding of how the charge carrier mobility and lifetime can be tuned. Here we use optical-pump–terahertz-probe spectroscopy to quantify how mobility and lifetime depend on the nanowire surfaces and on carrier density in unpassivated GaAs nanowires. We also present two alternative frameworks for the analysis of nanowire photoconductivity: one based on plasmon resonance and the other based on Maxwell–Garnett effective medium theory with the nanowires modelled as prolate ellipsoids. We find the electron mobility decreases significantly with decreasing nanowire diameter, as charge carriers experience increased scattering at nanowire surfaces. Reducing the diameter from 50 nm to 30 nm degrades the electron mobility by up to 47%. Photoconductivity dynamics were dominated by trapping at saturable states existing at the nanowire surface, and the trapping rate was highest for the nanowires of narrowest diameter. The maximum surface recombination velocity, which occurs in the limit of all traps being empty, was calculated as 1.3  ×  10 6 cm s −1 . We note that when selecting the optimum nanowire diameter for an ultrafast device, there is a trade-off between achieving a short lifetime and a high carrier mobility. To achieve high speed GaAs nanowire devices featuring the highest charge carrier mobilities and shortest lifetimes, we recommend operating the devices at low charge carrier densities. (paper)

Electron mobility in the inversion layers of fully depleted SOI films

Energy Technology Data Exchange (ETDEWEB)

Zaitseva, E. G., E-mail: ZaytsevaElza@yandex.ru; Naumova, O. V.; Fomin, B. I. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2017-04-15

The dependences of the electron mobility μ{sub eff} in the inversion layers of fully depleted double–gate silicon-on-insulator (SOI) metal–oxide–semiconductor (MOS) transistors on the density N{sub e} of induced charge carriers and temperature T are investigated at different states of the SOI film (inversion–accumulation) from the side of one of the gates. It is shown that at a high density of induced charge carriers of N{sub e} > 6 × 10{sup 12} cm{sup –2} the μeff(T) dependences allow the components of mobility μ{sub eff} that are related to scattering at surface phonons and from the film/insulator surface roughness to be distinguished. The μ{sub eff}(N{sub e}) dependences can be approximated by the power functions μ{sub eff}(N{sub e}) ∝ N{sub e}{sup −n}. The exponents n in the dependences and the dominant mechanisms of scattering of electrons induced near the interface between the SOI film and buried oxide are determined for different N{sub e} ranges and film states from the surface side.

AGM: A DSL for mobile cloud computing based on directed graph

Science.gov (United States)

Tanković, Nikola; Grbac, Tihana Galinac

2016-06-01

This paper summarizes a novel approach for consuming a domain specific language (DSL) by transforming it to a directed graph representation persisted by a graph database. Using such specialized database enables advanced navigation trough the stored model exposing only relevant subsets of meta-data to different involved services and components. We applied this approach in a mobile cloud computing system and used it to model several mobile applications in retail, supply chain management and merchandising domain. These application are distributed in a Software-as-a-Service (SaaS) fashion and used by thousands of customers in Croatia. We report on lessons learned and propose further research on this topic.

Weak coupling theory of the ripplon limited mobility of a 2-D electron lattice

International Nuclear Information System (INIS)

Dahm, A.J.; Mehrotra, R.

1981-01-01

The one ripplon-n phonon scattering contribution to the mobility of a 2D electron lattice supported by a liquid helium substrate is calculated in first order perturbation theory to all orders of n in the weak coupling limit. The Debye Waller factor is shown to limit the momentum transfer at large ripplon wave-vectors and high temperatures causing a minimum in the mobility as a function of temperature. (orig.)

Computer Series, 98. Electronics for Scientists: A Computer-Intensive Approach.

Science.gov (United States)

Scheeline, Alexander; Mork, Brian J.

1988-01-01

Reports the design for a principles-before-details presentation of electronics for an instrumental analysis class. Uses computers for data collection and simulations. Requires one semester with two 2.5-hour periods and two lectures per week. Includes lab and lecture syllabi. (MVL)

Two-parametric model of electron beam in computational dosimetry for radiation processing

International Nuclear Information System (INIS)

Lazurik, V.M.; Lazurik, V.T.; Popov, G.; Zimek, Z.

2016-01-01

Computer simulation of irradiation process of various materials with electron beam (EB) can be applied to correct and control the performances of radiation processing installations. Electron beam energy measurements methods are described in the international standards. The obtained results of measurements can be extended by implementation computational dosimetry. Authors have developed the computational method for determination of EB energy on the base of two-parametric fitting of semi-empirical model for the depth dose distribution initiated by mono-energetic electron beam. The analysis of number experiments show that described method can effectively consider random displacements arising from the use of aluminum wedge with a continuous strip of dosimetric film and minimize the magnitude uncertainty value of the electron energy evaluation, calculated from the experimental data. Two-parametric fitting method is proposed for determination of the electron beam model parameters. These model parameters are as follow: E 0 – energy mono-energetic and mono-directional electron source, X 0 – the thickness of the aluminum layer, located in front of irradiated object. That allows obtain baseline data related to the characteristic of the electron beam, which can be later on applied for computer modeling of the irradiation process. Model parameters which are defined in the international standards (like E p – the most probably energy and R p – practical range) can be linked with characteristics of two-parametric model (E 0 , X 0 ), which allows to simulate the electron irradiation process. The obtained data from semi-empirical model were checked together with the set of experimental results. The proposed two-parametric model for electron beam energy evaluation and estimation of accuracy for computational dosimetry methods on the base of developed model are discussed. - Highlights: • Experimental and computational methods of electron energy evaluation. • Development

MACBenAbim: A Multi-platform Mobile Application for searching keyterms in Computational Biology and Bioinformatics.

Science.gov (United States)

Oluwagbemi, Olugbenga O; Adewumi, Adewole; Esuruoso, Abimbola

2012-01-01

Computational biology and bioinformatics are gradually gaining grounds in Africa and other developing nations of the world. However, in these countries, some of the challenges of computational biology and bioinformatics education are inadequate infrastructures, and lack of readily-available complementary and motivational tools to support learning as well as research. This has lowered the morale of many promising undergraduates, postgraduates and researchers from aspiring to undertake future study in these fields. In this paper, we developed and described MACBenAbim (Multi-platform Mobile Application for Computational Biology and Bioinformatics), a flexible user-friendly tool to search for, define and describe the meanings of keyterms in computational biology and bioinformatics, thus expanding the frontiers of knowledge of the users. This tool also has the capability of achieving visualization of results on a mobile multi-platform context. MACBenAbim is available from the authors for non-commercial purposes.

Spin dynamics in high-mobility two-dimensional electron systems embedded in GaAs/AlGaAs quantum wells

Energy Technology Data Exchange (ETDEWEB)

Griesbeck, Michael

2012-11-22

Since many years there has been great effort to explore the spin dynamics in low-dimensional electron systems embedded in GaAs/AlGaAs based heterostructures for the purpose of quantum computation and spintronics applications. Advances in technology allow for the design of high quality and well-defined two-dimensional electron systems (2DES), which are perfectly suited for the study of the underlying physics that govern the dynamics of the electron spin system. In this work, spin dynamics in high-mobility 2DES is studied by means of the all-optical time-resolved Kerr/Faraday rotation technique. In (001)-grown 2DES, a strong in-plane spin dephasing anisotropy is studied, resulting from the interference of comparable Rashba and Dresselhaus contributions to the spin-orbit field (SOF). The dependence of this anisotropy on parameters like the confinement length of the 2DES, the sample temperature, as well as the electron density is demonstrated. Furthermore, coherent spin dynamics of an ensemble of ballistically moving electrons is studied without and within an applied weak magnetic field perpendicular to the sample plane, which forces the electrons to move on cyclotron orbits. Finally, strongly anisotropic spin dynamics is investigated in symmetric (110)-grown 2DES, using the resonant spin amplification method. Here, extremely long out-of-plane spin dephasing times can be achieved, in consequence of the special symmetry of the Dresselhaus SOF.

Simplified techniques of cerebral angiography using a mobile X-ray unit and computed radiography

International Nuclear Information System (INIS)

Gondo, Gakuji; Ishiwata, Yusuke; Yamashita, Toshinori; Iida, Takashi; Moro, Yutaka

1989-01-01

Simplified techniques of cerebral angiography using a mobile X-ray unit and computed radiography (CR) are discussed. Computed radiography is a digital radiography system in which an imaging plate is used as an X-ray detector and a final image is displayed on the film. In the angiograms performed with CR, the spatial frequency components can be enhanced for the easy analysis of fine blood vessels. Computed radiography has an automatic sensitivity and a latitude-setting mechanism, thus serving as an 'automatic camera.' This mechanism is useful for radiography with a mobile X-ray unit in hospital wards, intensive care units, or operating rooms where the appropriate setting of exposure conditions is difficult. We applied this mechanism to direct percutaneous carotid angiography and intravenous digital subtraction angiography with a mobile X-ray unit. Direct percutaneous carotid angiography using CR and a mobile X-ray unit were taken after the manual injection of a small amount of a contrast material through a fine needle. We performed direct percutaneous carotid angiography with this method 68 times on 25 cases from August 1986 to December 1987. Of the 68 angiograms, 61 were evaluated as good, compared with conventional angiography. Though the remaining seven were evaluated as poor, they were still diagnostically effective. This method is found useful for carotid angiography in emergency rooms, intensive care units, or operating rooms. Cerebral venography using CR and a mobile X-ray unit was done after the manual injection of a contrast material through the bilateral cubital veins. The cerebral venous system could be visualized from 16 to 24 seconds after the beginning of the injection of the contrast material. We performed cerebral venography with this method 14 times on six cases. These venograms were better than conventional angiograms in all cases. This method may be useful in managing patients suffering from cerebral venous thrombosis. (J.P.N.)

Electron mobility in supercritical ethane as a function of density and temperature

International Nuclear Information System (INIS)

Nishikawa, M.; Holroyd, R.A.; Sowada, U.

1980-01-01

The electron mobility is reported for ethane as a function of density at various temperatures above T/sub c/. The high pressure cell used permits measurements to 200 atm. Our analysis shows that theory is consistent with the ethane mobility results at low and intermediate densities. At densities less than 1 x 10 21 molecules/cm 3 electrons are scattered by isolated ethane molecules and the Lorentz equation is valid. At intermediate densities, μ/sub e/ correlates with the square of the velocity of sound, indicating that in dense fluids the adiabatic compressibility must be included. The data are consistent with a modified Cohen--Lekner equation, and the minimum in μ/sub e/N observed at densities just below d/sub c/ is qualitatively accounted for by changes in the adiabatic compressibility. Thus the concept of quasilocalization, suggested by others to qualitatively explain such minima, is unnecessary here. At higher densities an additional, unspecified, scattering mechanism becomes important

FY1995 community support by mobile agents; 1995 nendo mobile agent ni yoru community keisei shien

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The purpose is to develop fundamental technologies for navigation systems and mobile computing systems in museums, theme parks and cities. Concretely, we implement software agents into the mobile computing environment which consists of PHS, mobile computers and mobile robots, and realize various functions to access regional information. We have studied on Communityware which supports human activities and communities by using mobile agents implemented into mobile computers and town robots. The mobile agents, which intelligently process information obtained in physical and virtual worlds, access regional information which is omnipresent in the environment. With respect to the approach using mobile computers, we have provided one hundred mobile computers in the international conference on multiagent systems 1996 and carried out the first experimentation of mobile computing in the world. The mobile computer has two functions: Community Viewer which displays interactions between members of communities and Social Matchmaker which supports to hold meetings by searching for people who have common interests. With respect to the approach using town robots, we have developed a robot system which can robustly behave in a complex outdoor environment by using vision agents embedded in the environment. The system aims at support of people in streets. (NEDO)

Double pulse doped InGaAs/AlGaAs/GaAs pseudomorphic high-electron-mobility transistor heterostructures

International Nuclear Information System (INIS)

Egorov, A. Yu.; Gladyshev, A. G.; Nikitina, E. V.; Denisov, D. V.; Polyakov, N. K.; Pirogov, E. V.; Gorbazevich, A. A.

2010-01-01

Double pulse doped (δ-doped) InGaAs/AlGaAs/GaAs pseudomorphic high-electron-mobility transistor (HEMT) heterostructures were grown by molecular-beam epitaxy using a multiwafer technological system. The room-temperature electron mobility was determined by the Hall method as 6550 and 6000 cm 2 /(V s) at sheet electron densities of 3.00 x 10 12 and 3.36 x 10 12 cm -2 , respectively. HEMT heterostructures fabricated in a single process feature high uniformity of structural and electrical characteristics over the entire area of wafers 76.2 mm in diameter and high reproducibility of characteristics from process to process.

Theory of insulated gate field effect transistor with negative differential electron mobility

International Nuclear Information System (INIS)

Furman, A.S.

1995-09-01

We study the consequences of negative differential electron mobility in FETs using the field model and the gradual channel approximation. We find that the FET may show convective or absolute instability. The fluctuations growths is governed by diffusion law with negative effective diffusion coefficient. (author). 4 refs, 2 figs

Effect of field-dependent mobility on the escape probability. I. Electrons photoinjected in neopentane

International Nuclear Information System (INIS)

Mozumder, A.; Carmichael, I.

1978-01-01

A general procedure is described for calculating the escape probability of an electron against neutralization in the presence of an external field after it has been ejected into a dielectric liquid from a planar surface. The present paper utilizes the field-dependent electron mobility measurement in neopentane by Bakale and Schmidt. The calculated escape probability, upon averaging over the initial distribution, is compared with the current efficiency measurement of Holroyd et al. The median thermalization legnth, inferred from this comparison, depends in general upon the assumed form of initial distribution. It is less than the value obtained when the field dependence of the mobility is ignored but greater than that applicable to the high energy irradiation case. A plausible explanation is offered

High electron mobility and large magnetoresistance in the half-Heusler semimetal LuPtBi

KAUST Repository

Hou, Zhipeng; Wang, Wenhong; Xu, Guizhou; Zhang, Xiaoming; Wei, Zhiyang; Shen, Shipeng; Liu, Enke; Yao, Yuan; Chai, Yisheng; Sun, Young; Xi, Xuekui; Wang, Wenquan; Liu, Zhongyuan; Wu, Guangheng; Zhang, Xixiang

2015-01-01

Materials with high carrier mobility showing large magnetoresistance (MR) have recently received much attention because of potential applications in future high-performance magnetoelectric devices. Here, we report on an electron-hole

Quantum corrections to conductivity observed at intermediate magnetic fields in a high mobility GaAs/AlGaAs 2-dimensional electron gas

International Nuclear Information System (INIS)

Taboryski, R.; Veje, E.; Lindelof, P.E.

1990-01-01

Magnetoresistance with the field perpendicular to the 2-dimensional electron gas in a high mobility GaAs/AlGaAs heterostructure at low temperatures is studied. At the lowest magnetic field we observe the weak localization. At magnetic fields, where the product of the mobility and the magnetic field is of the order of unity, the quantum correction to conductivity due to the electron-electron interaction is as a source of magnetoresistance. A consistent analysis of experiments in this regime is for the first time performed. In addition to the well known electron-electron term with the expected temperature dependence, we find a new type of temperature independent quantum correction, which varies logarithmically with mobility. (orig.)

Kinase detection with gallium nitride based high electron mobility transistors.

Science.gov (United States)

Makowski, Matthew S; Bryan, Isaac; Sitar, Zlatko; Arellano, Consuelo; Xie, Jinqiao; Collazo, Ramon; Ivanisevic, Albena

2013-07-01

A label-free kinase detection system was fabricated by the adsorption of gold nanoparticles functionalized with kinase inhibitor onto AlGaN/GaN high electron mobility transistors (HEMTs). The HEMTs were operated near threshold voltage due to the greatest sensitivity in this operational region. The Au NP/HEMT biosensor system electrically detected 1 pM SRC kinase in ionic solutions. These results are pertinent to drug development applications associated with kinase sensing.

Apps for Angiosperms: The Usability of Mobile Computers and Printed Field Guides for UK Wild Flower and Winter Tree Identification

Science.gov (United States)

Stagg, Bethan C.; Donkin, Maria E.

2017-01-01

We investigated usability of mobile computers and field guide books with adult botanical novices, for the identification of wildflowers and deciduous trees in winter. Identification accuracy was significantly higher for wildflowers using a mobile computer app than field guide books but significantly lower for deciduous trees. User preference…

Effects of mobile phone-based app learning compared to computer-based web learning on nursing students: pilot randomized controlled trial.

Science.gov (United States)

Lee, Myung Kyung

2015-04-01

This study aimed to determine the effect of mobile-based discussion versus computer-based discussion on self-directed learning readiness, academic motivation, learner-interface interaction, and flow state. This randomized controlled trial was conducted at one university. Eighty-six nursing students who were able to use a computer, had home Internet access, and used a mobile phone were recruited. Participants were randomly assigned to either the mobile phone app-based discussion group (n = 45) or a computer web-based discussion group (n = 41). The effect was measured at before and after an online discussion via self-reported surveys that addressed academic motivation, self-directed learning readiness, time distortion, learner-learner interaction, learner-interface interaction, and flow state. The change in extrinsic motivation on identified regulation in the academic motivation (p = 0.011) as well as independence and ability to use basic study (p = 0.047) and positive orientation to the future in self-directed learning readiness (p = 0.021) from pre-intervention to post-intervention was significantly more positive in the mobile phone app-based group compared to the computer web-based discussion group. Interaction between learner and interface (p = 0.002), having clear goals (p = 0.012), and giving and receiving unambiguous feedback (p = 0.049) in flow state was significantly higher in the mobile phone app-based discussion group than it was in the computer web-based discussion group at post-test. The mobile phone might offer more valuable learning opportunities for discussion teaching and learning methods in terms of self-directed learning readiness, academic motivation, learner-interface interaction, and the flow state of the learning process compared to the computer.

From computational discovery to experimental characterization of a high hole mobility organic crystal.

KAUST Repository

Sokolov, Anatoliy N

2011-08-16

For organic semiconductors to find ubiquitous electronics applications, the development of new materials with high mobility and air stability is critical. Despite the versatility of carbon, exploratory chemical synthesis in the vast chemical space can be hindered by synthetic and characterization difficulties. Here we show that in silico screening of novel derivatives of the dinaphtho[2,3-b:2\\',3\\'-f]thieno[3,2-b]thiophene semiconductor with high hole mobility and air stability can lead to the discovery of a new high-performance semiconductor. On the basis of estimates from the Marcus theory of charge transfer rates, we identified a novel compound expected to demonstrate a theoretic twofold improvement in mobility over the parent molecule. Synthetic and electrical characterization of the compound is reported with single-crystal field-effect transistors, showing a remarkable saturation and linear mobility of 12.3 and 16 cm(2) V(-1) s(-1), respectively. This is one of the very few organic semiconductors with mobility greater than 10 cm(2) V(-1) s(-1) reported to date.

Density and temperature effects on electron mobilities in gaseous, critical and liquid n-hexane, cyclohexane, and cyclopentane

International Nuclear Information System (INIS)

Huang, S.S.-S.; Freeman, G.R.

1978-01-01

In the low density vapors the density normalized mobilities μn of thermal electrons decreased in the order n-hexane > cyclopentane > cyclohexane. Mobilities in the critical fluids were 16 cm 2 /V s in n-hexane, 23 in cyclohexane, and 22 in cyclopentane. Mobilities in the liquids were independent of field up to the highest value used, which was 1.5 Td in the hexanes and 0.9 Td in cyclopentane. The mobilities and their temperature dependences were interpreted in terms of a model

Mobility of charge carriers in electron-irradiated crystals of n-type Hg0.8Cd0.2Te

International Nuclear Information System (INIS)

Voitsekhovskii, A.V.; Kiryushkin, E.M.; Kokhanenko, A.P.; Kurbanov, K.R.; Lilenko, Yu.V.

1988-01-01

We present the results of an investigation of the behavior of the mobility of the charge carriers in Hg 1-x Cd x Te crystals with n-type conduction as a function of the dose of irradiation by electrons with an energy of 3.0 MeV at 300 K and the initial content of defects in the material. The complex character of the variation of the mobility of the electrons as a function of the dose observed when crystals of n-Hg 1-x Cd x Te (x ∼ 0.20) with different initial concentrations of defects are irradiated by fast electrons has been attributed to the influence of the factors of the shielding of the ionized scattering centers by electrons and the additional scattering of the charge carriers on the radiation defects. Good agreement between the experimental and calculated plots of the dependence of the mobility of electrons on the irradiation dose has been obtained with consideration of a model of the simultaneous introduction of donor (single charged) and acceptor (doubly charged) defects into a narrow-band semiconductor characterized by a degenerate and nonparabolic conduction band

Calculation and construction of electron-diffraction photographs using computer

International Nuclear Information System (INIS)

Khayurov, S.S.; Notkin, A.B.

1981-01-01

A method of computer construction and indexing of theoretical electronograms for monophase structures with arbitrary type of crystal lattice and for polyphase ones with known orientational coorrelations between phases is presented. Electron-diffraction photograph is presented, obtained from the foil area of two-phase VT22 alloy at β phase orientation in comparison with theoretical electron-diffraction photographs, built ap by computer, with the [100] β phase zone axis and with three variants of α phase orientation relatively to β phase. It is shown that on the experimental electron-diffraction photograph simultaneously presents α-phase three orientations, which reflexes can be indexing correctly [ru

Neuro-Inspired Computing with Stochastic Electronics

KAUST Repository

Naous, Rawan

2016-01-06

The extensive scaling and integration within electronic systems have set the standards for what is addressed to as stochastic electronics. The individual components are increasingly diverting away from their reliable behavior and producing un-deterministic outputs. This stochastic operation highly mimics the biological medium within the brain. Hence, building on the inherent variability, particularly within novel non-volatile memory technologies, paves the way for unconventional neuromorphic designs. Neuro-inspired networks with brain-like structures of neurons and synapses allow for computations and levels of learning for diverse recognition tasks and applications.

First-principles calculations of mobility

Science.gov (United States)

Krishnaswamy, Karthik

First-principles calculations can be a powerful predictive tool for studying, modeling and understanding the fundamental scattering mechanisms impacting carrier transport in materials. In the past, calculations have provided important qualitative insights, but numerical accuracy has been limited due to computational challenges. In this talk, we will discuss some of the challenges involved in calculating electron-phonon scattering and carrier mobility, and outline approaches to overcome them. Topics will include the limitations of models for electron-phonon interaction, the importance of grid sampling, and the use of Gaussian smearing to replace energy-conserving delta functions. Using prototypical examples of oxides that are of technological importance-SrTiO3, BaSnO3, Ga2O3, and WO3-we will demonstrate computational approaches to overcome these challenges and improve the accuracy. One approach that leads to a distinct improvement in the accuracy is the use of analytic functions for the band dispersion, which allows for an exact solution of the energy-conserving delta function. For select cases, we also discuss direct quantitative comparisons with experimental results. The computational approaches and methodologies discussed in the talk are general and applicable to other materials, and greatly improve the numerical accuracy of the calculated transport properties, such as carrier mobility, conductivity and Seebeck coefficient. This work was performed in collaboration with B. Himmetoglu, Y. Kang, W. Wang, A. Janotti and C. G. Van de Walle, and supported by the LEAST Center, the ONR EXEDE MURI, and NSF.

MOBILE COMPUTING USING ANDROID WITH AN EMPHASIZES ON ECONOMIC APPLICATION

Directory of Open Access Journals (Sweden)

Magnolia TILCA

2016-12-01

Full Text Available As result of the convergence of computers and mobile phones, Android comes with the great opportunity of implementing personal mobile applications in a Java language environment. The paper presents two main aspects concerning the new age of programming. The first aspect refers to the existing library of applications in economic domain. The paper extracts the most useful financial and business apps that run on Android smart-phones. The second aspect presents an example of building an economic application using one of Android’s various IDEs (Integrated Development Environments: Android Studio. The developed app calculates the prognosis of a business size starting from known statistic data sets and evaluates the effort of the business implementation, using the linear regression method. The app differs from other Android applications by the explicit answers that result from the regression calculus

A Collaborative Digital Pathology System for Multi-Touch Mobile and Desktop Computing Platforms

KAUST Repository

Jeong, W.

2013-06-13

Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server system that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch-enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. We introduce a domain-specific image-stack compression method that leverages real-time hardware decoding on mobile devices. It adaptively encodes image stacks in a decorrelated colour space to achieve extremely low bitrates (0.8 bpp) with very low loss of image quality. We evaluate the image quality of our compression method and the performance of our system for diagnosis with an in-depth user study. Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server systems that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

A Collaborative Digital Pathology System for Multi-Touch Mobile and Desktop Computing Platforms

KAUST Repository

Jeong, W.; Schneider, J.; Hansen, A.; Lee, M.; Turney, S. G.; Faulkner-Jones, B. E.; Hecht, J. L.; Najarian, R.; Yee, E.; Lichtman, J. W.; Pfister, H.

2013-01-01

Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server system that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch-enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. We introduce a domain-specific image-stack compression method that leverages real-time hardware decoding on mobile devices. It adaptively encodes image stacks in a decorrelated colour space to achieve extremely low bitrates (0.8 bpp) with very low loss of image quality. We evaluate the image quality of our compression method and the performance of our system for diagnosis with an in-depth user study. Collaborative slide image viewing systems are becoming increasingly important in pathology applications such as telepathology and E-learning. Despite rapid advances in computing and imaging technology, current digital pathology systems have limited performance with respect to remote viewing of whole slide images on desktop or mobile computing devices. In this paper we present a novel digital pathology client-server systems that supports collaborative viewing of multi-plane whole slide images over standard networks using multi-touch enabled clients. Our system is built upon a standard HTTP web server and a MySQL database to allow multiple clients to exchange image and metadata concurrently. © 2013 The Eurographics Association and John Wiley & Sons Ltd.

High mobility two-dimensional electron gases in nitride heterostructures with high Al composition AlGaN alloy barriers

International Nuclear Information System (INIS)

Li Guowang; Cao Yu; Xing Huili Grace; Jena, Debdeep

2010-01-01

We report high-electron mobility nitride heterostructures with >70% Al composition AlGaN alloy barriers grown by molecular beam epitaxy. Direct growth of such AlGaN layers on GaN resulted in hexagonal trenches and a low mobility polarization-induced charge. By applying growth interruption at the heterojunction, the surface morphology improved dramatically and the room temperature two-dimensional electron gas (2DEG) mobility increased by an order of magnitude, exceeding 1300 cm 2 /V s. The 2DEG density was tunable at 0.4-3.7x10 13 /cm 2 by varying the total barrier thickness (t). Surface barrier heights of the heterostructures were extracted and exhibited dependence on t.

GPU-accelerated computation of electron transfer.

Science.gov (United States)

Höfinger, Siegfried; Acocella, Angela; Pop, Sergiu C; Narumi, Tetsu; Yasuoka, Kenji; Beu, Titus; Zerbetto, Francesco

2012-11-05

Electron transfer is a fundamental process that can be studied with the help of computer simulation. The underlying quantum mechanical description renders the problem a computationally intensive application. In this study, we probe the graphics processing unit (GPU) for suitability to this type of problem. Time-critical components are identified via profiling of an existing implementation and several different variants are tested involving the GPU at increasing levels of abstraction. A publicly available library supporting basic linear algebra operations on the GPU turns out to accelerate the computation approximately 50-fold with minor dependence on actual problem size. The performance gain does not compromise numerical accuracy and is of significant value for practical purposes. Copyright © 2012 Wiley Periodicals, Inc.

Effect of electron-electron interaction on cyclotron resonance in high-mobility InAs/AlSb quantum wells

Energy Technology Data Exchange (ETDEWEB)

Krishtopenko, S. S., E-mail: sergey.krishtopenko@mail.ru; Gavrilenko, V. I. [Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105 (Russian Federation); Lobachevsky State University, 23 Prospekt Gagarina, 603950 Nizhny Novgorod (Russian Federation); Ikonnikov, A. V. [Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105 (Russian Federation); Orlita, M. [Laboratoire National des Champs Magnétiques Intenses (LNCMI-G), CNRS, 25 rue des Martyrs, B.P. 166, 38042 Grenoble (France); Sadofyev, Yu. G. [P.N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991, GSP-1, 53 Leninskiy Prospect (Russian Federation); Goiran, M. [Laboratoire National des Champs Magnétiques Intenses (LNCMI-T), CNRS, 143 Avenue de Rangueil, 31400 Toulouse (France); Teppe, F.; Knap, W. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Universite Montpellier II, 34095 Montpellier (France)

2015-03-21

We report observation of electron-electron (e-e) interaction effect on cyclotron resonance (CR) in InAs/AlSb quantum well heterostructures. High mobility values allow us to observe strongly pronounced triple splitting of CR line at noninteger filling factors of Landau levels ν. At magnetic fields, corresponding to ν > 4, experimental values of CR energies are in good agreement with single-electron calculations on the basis of eight-band k ⋅ p Hamiltonian. In the range of filling factors 3 < ν < 4 pronounced, splitting of CR line, exceeding significantly the difference in single-electron CR energies, is discovered. The strength of the splitting increases when occupation of the partially filled Landau level tends to a half, being in qualitative agreement with previous prediction by MacDonald and Kallin [Phys. Rev. B 40, 5795 (1989)]. We demonstrate that such behaviour of CR modes can be quantitatively described if one takes into account both electron correlations and the mixing between conduction and valence bands in the calculations of matrix elements of e-e interaction.

Nonmonotonous electron mobility due to structurally induced resonant coupling of subband states in an asymmetric double quantum well

Directory of Open Access Journals (Sweden)

R. K. Nayak

2015-11-01

Full Text Available We show that sharp nonmonotic variation of low temperature electron mobility μ can be achieved in GaAs/AlxGa1-xAs barrier delta-doped double quantum well structure due to quantum mechanical transfer of subband electron wave functions within the wells. We vary the potential profile of the coupled structure as a function of the doping concentration in order to bring the subbands into resonance such that the subband energy levels anticross and the eigen states of the coupled structure equally share both the wells thereby giving rise to a dip in mobility. When the wells are of equal widths, the dip in mobility occurs under symmetric doping of the side barriers. In case of unequal well widths, the resonance can be obtained by suitable asymmetric variation of the doping concentrations. The dip in mobility becomes sharp and also the wavy nature of mobility takes a rectangular shape by increasing the barrier width. We show that the dip in mobility at resonance is governed by the interface roughness scattering through step like changes in the subband mobilities. It is also gratifying to show that the drop in mobility at the onset of occupation of second subband is substantially supressed through the quantum mechanical transfer of subband wave functions between the wells. Our results can be utilized for performance enhancement of coupled quantum well devices.

High electron mobility and quantum oscillations in non-encapsulated ultrathin semiconducting Bi2O2Se

Science.gov (United States)

Wu, Jinxiong; Yuan, Hongtao; Meng, Mengmeng; Chen, Cheng; Sun, Yan; Chen, Zhuoyu; Dang, Wenhui; Tan, Congwei; Liu, Yujing; Yin, Jianbo; Zhou, Yubing; Huang, Shaoyun; Xu, H. Q.; Cui, Yi; Hwang, Harold Y.; Liu, Zhongfan; Chen, Yulin; Yan, Binghai; Peng, Hailin

2017-07-01

High-mobility semiconducting ultrathin films form the basis of modern electronics, and may lead to the scalable fabrication of highly performing devices. Because the ultrathin limit cannot be reached for traditional semiconductors, identifying new two-dimensional materials with both high carrier mobility and a large electronic bandgap is a pivotal goal of fundamental research. However, air-stable ultrathin semiconducting materials with superior performances remain elusive at present. Here, we report ultrathin films of non-encapsulated layered Bi2O2Se, grown by chemical vapour deposition, which demonstrate excellent air stability and high-mobility semiconducting behaviour. We observe bandgap values of ˜0.8 eV, which are strongly dependent on the film thickness due to quantum-confinement effects. An ultrahigh Hall mobility value of >20,000 cm2 V-1 s-1 is measured in as-grown Bi2O2Se nanoflakes at low temperatures. This value is comparable to what is observed in graphene grown by chemical vapour deposition and at the LaAlO3-SrTiO3 interface, making the detection of Shubnikov-de Haas quantum oscillations possible. Top-gated field-effect transistors based on Bi2O2Se crystals down to the bilayer limit exhibit high Hall mobility values (up to 450 cm2 V-1 s-1), large current on/off ratios (>106) and near-ideal subthreshold swing values (˜65 mV dec-1) at room temperature. Our results make Bi2O2Se a promising candidate for future high-speed and low-power electronic applications.

Ab-initio Study of the Electron Mobility in a Functionalized UiO-66 Metal Organic Framework

Science.gov (United States)

Musho, Terence D.; Yasin, Alhassan S.

2018-03-01

This study leverages density functional theory accompanied with Boltzmann transport equation approaches to investigate the electronic mobility as a function of inorganic substitution and functionalization in a thermally stable UiO-66 metal-organic framework (MOF). The MOFs investigated are based on Zr-UiO-66 MOF with three functionalization groups of benzene dicarboxylate (BDC), BDC functionalized with an amino group (BDC + NH_2 ) and a nitro group (BDC + NO_2 ). The design space of this study is bound by UiO-66(M)-R, [M=Zr , Ti, Hf; R=BDC , BDC+NO_2 , BDC+NH_2 ]. The elastic modulus was not found to vary significantly over the structural modification of the design space for either functionalization or inorganic substitution. However, the electron-phonon scattering potential was found to be controllable by up to 30% through controlled inorganic substitution in the metal clusters of the MOF structure. The highest electron mobility was predicted for a UiO-66(Hf_5Zr_1 ) achieving a value of approximately 1.4× 10^{-3} cm^2 /V s. It was determined that functionalization provides a controlled method of modulating the charge density, while inorganic substitution provides a controlled method of modulating the electronic mobility. Within the proposed design space the electrical conductivity was able to be increased by approximately three times the base conductivity through a combination of inorganic substitution and functionalization.

Computational Research on Mobile Pastoralism Using Agent-Based Modeling and Satellite Imagery.

Directory of Open Access Journals (Sweden)

Takuto Sakamoto

Full Text Available Dryland pastoralism has long attracted considerable attention from researchers in diverse fields. However, rigorous formal study is made difficult by the high level of mobility of pastoralists as well as by the sizable spatio-temporal variability of their environment. This article presents a new computational approach for studying mobile pastoralism that overcomes these issues. Combining multi-temporal satellite images and agent-based modeling allows a comprehensive examination of pastoral resource access over a realistic dryland landscape with unpredictable ecological dynamics. The article demonstrates the analytical potential of this approach through its application to mobile pastoralism in northeast Nigeria. Employing more than 100 satellite images of the area, extensive simulations are conducted under a wide array of circumstances, including different land-use constraints. The simulation results reveal complex dependencies of pastoral resource access on these circumstances along with persistent patterns of seasonal land use observed at the macro level.

Computation of the average energy for LXY electrons

International Nuclear Information System (INIS)

Grau Carles, A.; Grau, A.

1996-01-01

The application of an atomic rearrangement model in which we only consider the three shells K, L and M, to compute the counting efficiency for electron capture nuclides, requires a fine averaged energy value for LMN electrons. In this report, we illustrate the procedure with two example, ''125 I and ''109 Cd. (Author) 4 refs

Local imaging of high mobility two-dimensional electron systems with virtual scanning tunneling microscopy

Energy Technology Data Exchange (ETDEWEB)

Pelliccione, M. [Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106 (United States); Bartel, J.; Goldhaber-Gordon, D. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305 (United States); Sciambi, A. [Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Pfeiffer, L. N.; West, K. W. [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

2014-11-03

Correlated electron states in high mobility two-dimensional electron systems (2DESs), including charge density waves and microemulsion phases intermediate between a Fermi liquid and Wigner crystal, are predicted to exhibit complex local charge order. Existing experimental studies, however, have mainly probed these systems at micron to millimeter scales rather than directly mapping spatial organization. Scanning probes should be well-suited to study the spatial structure of these states, but high mobility 2DESs are found at buried semiconductor interfaces, beyond the reach of conventional scanning tunneling microscopy. Scanning techniques based on electrostatic coupling to the 2DES deliver important insights, but generally with resolution limited by the depth of the 2DES. In this letter, we present our progress in developing a technique called “virtual scanning tunneling microscopy” that allows local tunneling into a high mobility 2DES. Using a specially designed bilayer GaAs/AlGaAs heterostructure where the tunnel coupling between two separate 2DESs is tunable via electrostatic gating, combined with a scanning gate, we show that the local tunneling can be controlled with sub-250 nm resolution.

Molecular gated-AlGaN/GaN high electron mobility transistor for pH detection.

Science.gov (United States)

Ding, Xiangzhen; Yang, Shuai; Miao, Bin; Gu, Le; Gu, Zhiqi; Zhang, Jian; Wu, Baojun; Wang, Hong; Wu, Dongmin; Li, Jiadong

2018-04-18

A molecular gated-AlGaN/GaN high electron mobility transistor has been developed for pH detection. The sensing surface of the sensor was modified with 3-aminopropyltriethoxysilane to provide amphoteric amine groups, which would play the role of receptors for pH detection. On modification with 3-aminopropyltriethoxysilane, the transistor exhibits good chemical stability in hydrochloric acid solution and is sensitive for pH detection. Thus, our molecular gated-AlGaN/GaN high electron mobility transistor acheived good electrical performances such as chemical stability (remained stable in hydrochloric acid solution), good sensitivity (37.17 μA/pH) and low hysteresis. The results indicate a promising future for high-quality sensors for pH detection.

Development of a 10 kGy(Si) rad hard controller for a mobile robot using COTS

International Nuclear Information System (INIS)

Alexandre, J.M.; Marceau, M.

1999-01-01

The CEA has developed a 10 kGy(Si) hardened controller using only COTS (Commercial-Off-The-Shelf devices), to equip the mobile robot Andros. An electronic architecture adapted to the constraint of hardening have been carried out, leading to the construction of a complete set of electronics modules (power electronic, control computer). (authors)

Integration of a mobile-integrated therapy with electronic health records: lessons learned.

Science.gov (United States)

Peeples, Malinda M; Iyer, Anand K; Cohen, Joshua L

2013-05-01

Responses to the chronic disease epidemic have predominantly been standardized in their approach to date. Barriers to better health outcomes remain, and effective management requires patient-specific data and disease state knowledge be presented in methods that foster clinical decision-making and patient self-management. Mobile technology provides a new platform for data collection and patient-provider communication. The mobile device represents a personalized platform that is available to the patient on a 24/7 basis. Mobile-integrated therapy (MIT) is the convergence of mobile technology, clinical and behavioral science, and scientifically validated clinical outcomes. In this article, we highlight the lessons learned from functional integration of a Food and Drug Administration-cleared type 2 diabetes MIT into the electronic health record (EHR) of a multiphysician practice within a large, urban, academic medical center. In-depth interviews were conducted with integration stakeholder groups: mobile and EHR software and information technology teams, clinical end users, project managers, and business analysts. Interviews were summarized and categorized into lessons learned using the Architecture for Integrated Mobility® framework. Findings from the diverse stakeholder group of a MIT-EHR integration project indicate that user workflow, software system persistence, environment configuration, device connectivity and security, organizational processes, and data exchange heuristics are key issues that must be addressed. Mobile-integrated therapy that integrates patient self-management data with medical record data provides the opportunity to understand the potential benefits of bidirectional data sharing and reporting that are most valuable in advancing better health and better care in a cost-effective way that is scalable for all chronic diseases. © 2013 Diabetes Technology Society.

Electronic digital computers their use in science and engineering

CERN Document Server

Alt, Franz L

1958-01-01

Electronic Digital Computers: Their Use in Science and Engineering describes the principles underlying computer design and operation. This book describes the various applications of computers, the stages involved in using them, and their limitations. The machine is composed of the hardware which is run by a program. This text describes the use of magnetic drum for storage of data and some computing. The functions and components of the computer include automatic control, memory, input of instructions by using punched cards, and output from resulting information. Computers operate by using numbe

Digital watermarking opportunities enabled by mobile media proliferation

Science.gov (United States)

Modro, Sierra; Sharma, Ravi K.

2009-02-01

Consumer usages of mobile devices and electronic media are changing. Mobile devices now include increased computational capabilities, mobile broadband access, better integrated sensors, and higher resolution screens. These enhanced features are driving increased consumption of media such as images, maps, e-books, audio, video, and games. As users become more accustomed to using mobile devices for media, opportunities arise for new digital watermarking usage models. For example, transient media, like images being displayed on screens, could be watermarked to provide a link between mobile devices. Applications based on these emerging usage models utilizing watermarking can provide richer user experiences and drive increased media consumption. We describe the enabling factors and highlight a few of the usage models and new opportunities. We also outline how the new opportunities are driving further innovation in watermarking technologies. We discuss challenges in market adoption of applications based on these usage models.

Electronic white cane with GPS radar-based concept as blind mobility enhancement without distance limitation

Science.gov (United States)

Halim, Suharsono; Handafiah, Finna; Aprilliyani, Ria; Udhiarto, Arief

2018-02-01

The Indonesian Ministry of Social Affairs, in July 2012, informed that the number of blind in Indonesia has been the largest among to the people with other disabilities. The most common tools utilized to help the blind was a conventional cane which has limited features and therefore it was difficult to be used as a mobilization tools. Moreover, the conventional cane cannot assist them or their family when the blind gets lost. In this research, we designed and implemented an electronic white cane with the concept of radar and global positioning system (GPS). The purpose of this research was to design and develop an electronic white cane which can enhance the mobility of the blind without distance coverage limitation. Utilizing ultrasonic sensors as a distance measurement and a servo motor as an actuator, the produced radar system is able to map an area with maximum distance and coverage angle of 5 meters and 180° respectively. The blind senses the obstacle around them from the vibration generated by five vibration motors. The vibration becomes more intense when the obstacle is detected closer. In addition, we implemented a GPS to monitor the blind's position and allow their family to find them easily when the blind need a help. Based on the tests performed, we have successfully developed an electronic white cane that can be a solution to improve the blind's mobility.

Mobile Social Computing for Destination Marketing: Valuing Territoriality and Social Contagion

DEFF Research Database (Denmark)

Tussyadiah, Iis

of influence enablers that leads to social contagion and stimulate territorial behavior that drives and changes people’s mobility within tourism destinations. It was identified in this study that locative media encourage the expansion of experience territory by presenting new approaches to territorial......Mobile social computing has become an important platform for daily experiences and has caused a tremendous impact on people’s interaction with and interpretation of objects, materials, and images of tourist places. This study explores how locative media shapes tourist behavior and how destination...... marketers should respond to this behavior with appropriate marketing strategies. This study identifies that locative media provide tourists with the playfulness of pursuing rewards and competing (as well as staying connected) with their social network while traveling. Locative media function as a platform...

Study on payments through mobile phones

Directory of Open Access Journals (Sweden)

Anca Ioana ANDREESCU

2006-01-01

Full Text Available The evolution of information and communications technology, together with the increasing use of electronic commerce, phones and mobile applications, have facilitated mobile payments to become an alternative payment method for buyers and vendors. Mobile payments offer various opportunities to business environment and became a starting point in the transition from electronic to mobile. This paper aims to analyze the present situation of the mobile payment methods and to identify the effects that mobile payment systems have on electronic commerce.

Analysis of Proton Radiation Effects on Gallium Nitride High Electron Mobility Transistors

Science.gov (United States)

2017-03-01

non - ionizing proton radiation damage effects at different energy levels on a GaN-on-silicon high electron mobility transistor...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) In this work, a physics-based simulation of non - ionizing proton radiation damage effects at different...Polarization . . . . . . . . . . . . . . 6 2.3 Non - Ionizing Radiation Damage Effects . . . . . . . . . . . . . . . 10 2.4 Non - Ionizing Radiation Damage in

Investigation of different classifiers and channel configurations of a mobile P300-based brain-computer interface.

Science.gov (United States)

Ludwig, Simone A; Kong, Jun

2017-12-01

Innovative methods and new technologies have significantly improved the quality of our daily life. However, disabled people, for example those that cannot use their arms and legs anymore, often cannot benefit from these developments, since they cannot use their hands to interact with traditional interaction methods (such as mouse or keyboard) to communicate with a computer system. A brain-computer interface (BCI) system allows such a disabled person to control an external device via brain waves. Past research mostly dealt with static interfaces, which limit users to a stationary location. However, since we are living in a world that is highly mobile, this paper evaluates a speller interface on a mobile phone used in a moving condition. The spelling experiments were conducted with 14 able-bodied subjects using visual flashes as the stimulus to spell 47 alphanumeric characters (38 letters and 9 numbers). This data was then used for the classification experiments. In par- ticular, two research directions are pursued. The first investigates the impact of different classification algorithms, and the second direction looks at the channel configuration, i.e., which channels are most beneficial in terms of achieving the highest classification accuracy. The evaluation results indicate that the Bayesian Linear Discriminant Analysis algorithm achieves the best accuracy. Also, the findings of the investigation on the channel configuration, which can potentially reduce the amount of data processing on a mobile device with limited computing capacity, is especially useful in mobile BCIs.

Comparative analysis of the influence on consumers via mobile phones and computers

Directory of Open Access Journals (Sweden)

Jevremović Milica

2016-01-01

Full Text Available Business operations are nowadays characterized by a rapid development of technology and marketers are therefore searching for most efficient methods for drawing the attention of consumers to their business and occupying a position in their consciousness. The possession and use of mobile phones have become an integral part of lives of all consumers. This work investigates whether there are any differences in the degree of influencing consumers who watch advertising content via their mobile phones, in comparison to the influence on those watching the same content on computers, and how big they are, as well as whether the opinion of respondents concerning interactivity (perceived interactivity of the observed content differs from the actual, existing interactivity.

Computer Conferencing and Electronic Messaging. Conference Proceedings (Guelph, Ontario, Canada, January 22-23, 1985).

Science.gov (United States)

Guelph Univ. (Ontario).

This 21-paper collection examines various issues in electronic networking and conferencing with computers, including design issues, conferencing in education, electronic messaging, computer conferencing applications, social issues of computer conferencing, and distributed computer conferencing. In addition to a keynote address, "Computer…

Three-dimensional image acquisition and reconstruction system on a mobile device based on computer-generated integral imaging.

Science.gov (United States)

Erdenebat, Munkh-Uchral; Kim, Byeong-Jun; Piao, Yan-Ling; Park, Seo-Yeon; Kwon, Ki-Chul; Piao, Mei-Lan; Yoo, Kwan-Hee; Kim, Nam

2017-10-01

A mobile three-dimensional image acquisition and reconstruction system using a computer-generated integral imaging technique is proposed. A depth camera connected to the mobile device acquires the color and depth data of a real object simultaneously, and an elemental image array is generated based on the original three-dimensional information for the object, with lens array specifications input into the mobile device. The three-dimensional visualization of the real object is reconstructed on the mobile display through optical or digital reconstruction methods. The proposed system is implemented successfully and the experimental results certify that the system is an effective and interesting method of displaying real three-dimensional content on a mobile device.

Effectiveness and cost-effectiveness of computer and other electronic aids for smoking cessation: a systematic review and network meta-analysis.

Science.gov (United States)

Chen, Y-F; Madan, J; Welton, N; Yahaya, I; Aveyard, P; Bauld, L; Wang, D; Fry-Smith, A; Munafò, M R

2012-01-01

Smoking is harmful to health. On average, lifelong smokers lose 10 years of life, and about half of all lifelong smokers have their lives shortened by smoking. Stopping smoking reverses or prevents many of these harms. However, cessation services in the NHS achieve variable success rates with smokers who want to quit. Approaches to behaviour change can be supplemented with electronic aids, and this may significantly increase quit rates and prevent a proportion of cases that relapse. The primary research question we sought to answer was: What is the effectiveness and cost-effectiveness of internet, pc and other electronic aids to help people stop smoking? We addressed the following three questions: (1) What is the effectiveness of internet sites, computer programs, mobile telephone text messages and other electronic aids for smoking cessation and/or reducing relapse? (2) What is the cost-effectiveness of incorporating internet sites, computer programs, mobile telephone text messages and other electronic aids into current nhs smoking cessation programmes? and (3) What are the current gaps in research into the effectiveness of internet sites, computer programs, mobile telephone text messages and other electronic aids to help people stop smoking? For the effectiveness review, relevant primary studies were sought from The Cochrane Library [Cochrane Central Register of Controlled Trials (CENTRAL)] 2009, Issue 4, and MEDLINE (Ovid), EMBASE (Ovid), PsycINFO (Ovid), Health Management Information Consortium (HMIC) (Ovid) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost) from 1980 to December 2009. In addition, NHS Economic Evaluation Database (NHS EED) and Database of Abstracts of Reviews of Effects (DARE) were searched for information on cost-effectiveness and modelling for the same period. Reference lists of included studies and of relevant systematic reviews were examined to identify further potentially relevant studies. Research registries

Cloud computing for enhanced mobile health applications

CSIR Research Space (South Africa)

Nkosi, MT

2010-11-01

Full Text Available Mobile devices are being considered as service platforms for mobile health information delivery, access and communication. However mobiles face challenges with regard to delivering secure multimedia based health services due to limitations...

The Effects of Mobile-Computer-Supported Collaborative Learning: Meta-Analysis and Critical Synthesis.

Science.gov (United States)

Sung, Yao-Ting; Yang, Je-Ming; Lee, Han-Yueh

2017-08-01

One of the trends in collaborative learning is using mobile devices for supporting the process and products of collaboration, which has been forming the field of mobile-computer-supported collaborative learning (mCSCL). Although mobile devices have become valuable collaborative learning tools, evaluative evidence for their substantial contributions to collaborative learning is still scarce. The present meta-analysis, which included 48 peer-reviewed journal articles and doctoral dissertations written over a 16-year period (2000-2015) involving 5,294 participants, revealed that mCSCL has produced meaningful improvements for collaborative learning, with an overall mean effect size of 0.516. Moderator variables, such as domain subject, group size, teaching method, intervention duration, and reward method were related to different effect sizes. The results provided implications for future research and practice, such as suggestions on how to appropriately use the functionalities of mobile devices, how to best leverage mCSCL through effective group learning mechanisms, and what outcome variables should be included in future studies to fully elucidate the process and products of mCSCL.

N-polar GaN epitaxy and high electron mobility transistors

International Nuclear Information System (INIS)

Wong, Man Hoi; Keller, Stacia; Dasgupta, Nidhi Sansaptak; Denninghoff, Daniel J; Kolluri, Seshadri; Brown, David F; Lu, Jing; Fichtenbaum, Nicholas A; Ahmadi, Elaheh; DenBaars, Steven P; Speck, James S; Mishra, Umesh K; Singisetti, Uttam; Chini, Alessandro; Rajan, Siddharth

2013-01-01

This paper reviews the progress of N-polar (0001-bar) GaN high frequency electronics that aims at addressing the device scaling challenges faced by GaN high electron mobility transistors (HEMTs) for radio-frequency and mixed-signal applications. Device quality (Al, In, Ga)N materials for N-polar heterostructures are developed using molecular beam epitaxy and metalorganic chemical vapor deposition. The principles of polarization engineering for designing N-polar HEMT structures will be outlined. The performance, scaling behavior and challenges of microwave power devices as well as highly-scaled depletion- and enhancement-mode devices employing advanced technologies including self-aligned processes, n+ (In,Ga)N ohmic contact regrowth and high aspect ratio T-gates will be discussed. Recent research results on integrating N-polar GaN with Si for prospective novel applications will also be summarized. (invited review)

Protecting software agents from malicious hosts using quantum computing

Science.gov (United States)

Reisner, John; Donkor, Eric

2000-07-01

We evaluate how quantum computing can be applied to security problems for software agents. Agent-based computing, which merges technological advances in artificial intelligence and mobile computing, is a rapidly growing domain, especially in applications such as electronic commerce, network management, information retrieval, and mission planning. System security is one of the more eminent research areas in agent-based computing, and the specific problem of protecting a mobile agent from a potentially hostile host is one of the most difficult of these challenges. In this work, we describe our agent model, and discuss the capabilities and limitations of classical solutions to the malicious host problem. Quantum computing may be extremely helpful in addressing the limitations of classical solutions to this problem. This paper highlights some of the areas where quantum computing could be applied to agent security.

Dielectric and barrier thickness fluctuation scattering in Al2O3/AlGaN/GaN double heterojunction high-electron mobility transistors

International Nuclear Information System (INIS)

Ji, Dong; Lu, Yanwu; Liu, Bing; Liu, Guipeng; Zhu, Qinsheng; Wang, Zhanguo

2013-01-01

The two-dimensional electron gas (2DEG) mobility limited by dielectric and barrier thickness fluctuations (TF) scattering in Al 2 O 3 /AlGaN/GaN double heterojunction high-electron mobility transistors (HEMTs) is calculated. Calculation shows that thickness fluctuation scattering is the main limitation in Al 2 O 3 /AlGaN/GaN double heterojunction HEMTs with thin Al 2 O 3 layer thicknesses. In addition, a study of 2DEG mobility as a function of 2DEG density, n s , shows that TF scattering acts as the main limitation when n s exceeds 2 × 10 12 cm −2 . The results may be used to design HEMTs to obtain higher 2DEG mobilities by modulating the dielectric layer and barrier thicknesses or 2DEG density. - Highlights: • The mobility limited by thickness fluctuation (TF) scattering is studied. • Results show that thickness fluctuation scattering is the main limitation. • Two-dimensional electron gas (2DEG) mobility is a function of 2DEG density. • TF scattering is the main limitation when 2DEG density exceeds 2 × 10 12 cm −2

Computer simulation of high resolution transmission electron micrographs: theory and analysis

International Nuclear Information System (INIS)

Kilaas, R.

1985-03-01

Computer simulation of electron micrographs is an invaluable aid in their proper interpretation and in defining optimum conditions for obtaining images experimentally. Since modern instruments are capable of atomic resolution, simulation techniques employing high precision are required. This thesis makes contributions to four specific areas of this field. First, the validity of a new method for simulating high resolution electron microscope images has been critically examined. Second, three different methods for computing scattering amplitudes in High Resolution Transmission Electron Microscopy (HRTEM) have been investigated as to their ability to include upper Laue layer (ULL) interaction. Third, a new method for computing scattering amplitudes in high resolution transmission electron microscopy has been examined. Fourth, the effect of a surface layer of amorphous silicon dioxide on images of crystalline silicon has been investigated for a range of crystal thicknesses varying from zero to 2 1/2 times that of the surface layer

High-electron-mobility GaN grown on free-standing GaN templates by ammonia-based molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Kyle, Erin C. H., E-mail: erinkyle@umail.ucsb.edu; Kaun, Stephen W.; Burke, Peter G.; Wu, Feng; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Wu, Yuh-Renn [Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, Taipei City 10617, Taiwan (China)

2014-05-21

The dependence of electron mobility on growth conditions and threading dislocation density (TDD) was studied for n{sup −}-GaN layers grown by ammonia-based molecular beam epitaxy. Electron mobility was found to strongly depend on TDD, growth temperature, and Si-doping concentration. Temperature-dependent Hall data were fit to established transport and charge-balance equations. Dislocation scattering was analyzed over a wide range of TDDs (∼2 × 10{sup 6} cm{sup −2} to ∼2 × 10{sup 10} cm{sup −2}) on GaN films grown under similar conditions. A correlation between TDD and fitted acceptor states was observed, corresponding to an acceptor state for almost every c lattice translation along each threading dislocation. Optimized GaN growth on free-standing GaN templates with a low TDD (∼2 × 10{sup 6} cm{sup −2}) resulted in electron mobilities of 1265 cm{sup 2}/Vs at 296 K and 3327 cm{sup 2}/Vs at 113 K.

Suppressed carrier density for the patterned high mobility two-dimensional electron gas at γ-Al2O3/SrTiO3 heterointerfaces

DEFF Research Database (Denmark)

Niu, Wei; Gan, Yulin; Christensen, Dennis Valbjørn

2017-01-01

The two-dimensional electron gas (2DEG) at the non-isostructural interface between spinel γ-Al2O3 and perovskite SrTiO3 is featured by a record electron mobility among complex oxide interfaces in addition to a high carrier density up to the order of 1015 cm-2. Herein, we report on the patterning...... is found to be approximately 3×1013 cm-2, much lower than that of the unpatterned sample (~1015 cm-2). Remarkably, a high electron mobility of approximately 3,600 cm2V-1s-1 was obtained at low temperatures for the patterned 2DEG at a carrier density of ~ 7×1012 cm-2, which exhibits clear Shubnikov-de Hass...... quantum oscillations. The patterned high-mobility 2DEG at the γ-Al2O3/SrTiO3 interface paves the way for the design and application of spinel/perovskite interfaces for high-mobility all-oxide electronic devic...

Innovative Secure Mobile Banking Services

Directory of Open Access Journals (Sweden)

Mousa T AL-Akhras

2011-01-01

Full Text Available Due to the widespread use of computer technologies in almost all aspects of life, organisations that are connected to the Internet started extending their services to their customers to include new applications and services that satisfy their customers’ desires to make better businesses. One of these emerging applications is mobile banking. The term mobile banking (or m-banking describes the banking services that the user can perform via a mobile device ubiquitously at anytime and from anywhere. In order for users to access their accounts, they need a mobile device and network connectivity. Therefore, sitting in front of a computer is not a requirement anymore; accessing accounts can occur while users are waiting their turn at the dentist clinic or relaxing at the beach! This paper explores the opportunities of using mobile technology in the electronic banking (e-banking sector to enhance existing banking services by moving toward m-banking using mobile devices and wireless media that can provide opportunities for ubiquitous access to the banking services as mobile technologies can be used at anytime and from anywhere. The technical problems encountered while using the mobile devices presents some technical difficulties and challenges for the m-banking. In this paper we introduce a mobile system that demonstrates the flexibility gained out of this technology and covers the major aspects of such kind of applications. The proposed system covers two parts: the customer services (user interface and the security aspects. In the user interface part, banking facility is provided to the user through the mobile device to implement banking transactions. The model provides customers with the services: billing payments, transferring of funds, viewing of customer’s accounts and transactions, allowing the user to change his/her password and request a cheque book. The application takes into consideration security aspects, it satisfies the following

Solution-processable ambipolar diketopyrrolopyrrole-selenophene polymer with unprecedentedly high hole and electron mobilities.

Science.gov (United States)

Lee, Junghoon; Han, A-Reum; Kim, Jonggi; Kim, Yiho; Oh, Joon Hak; Yang, Changduk

2012-12-26

There is a fast-growing demand for polymer-based ambipolar thin-film transistors (TFTs), in which both n-type and p-type transistor operations are realized in a single layer, while maintaining simplicity in processing. Research progress toward this end is essentially fueled by molecular engineering of the conjugated backbones of the polymers and the development of process architectures for device fabrication, which has recently led to hole and electron mobilities of more than 1.0 cm(2) V(-1) s(-1). However, ambipolar polymers with even higher performance are still required. By taking into account both the conjugated backbone and side chains of the polymer component, we have developed a dithienyl-diketopyrrolopyrrole (TDPP) and selenophene containing polymer with hybrid siloxane-solubilizing groups (PTDPPSe-Si). A synergistic combination of rational polymer backbone design, side-chain dynamics, and solution processing affords an enormous boost in ambipolar TFT performance, resulting in unprecedentedly high hole and electron mobilities of 3.97 and 2.20 cm(2) V(-1) s(-1), respectively.

Electron correlation in molecules: concurrent computation Many-Body Perturbation Theory (ccMBPT) calculations using macrotasking on the NEC SX-3/44 computer

International Nuclear Information System (INIS)

Moncrieff, D.; Wilson, S.

1992-06-01

The ab initio determination of the electronic structure of molecules is a many-fermion problem involving the approximate description of the motion of the electrons in the field of fixed nuclei. It is an area of research which demands considerable computational resources but having enormous potential in fields as diverse as interstellar chemistry and drug design, catalysis and solid state chemistry, molecular biology and environmental chemistry. Electronic structure calculations almost invariably divide into two main stages: the approximate solution of an independent electron model, in which each electron moves in the average field created by the other electrons in the system, and then, the more computationally demanding determination of a series of corrections to this model, the electron correlation effects. The many-body perturbation theory expansion affords a systematic description of correlation effects, which leads directly to algorithms which are suitable for concurrent computation. We term this concurrent computation Many-Body Perturbation Theory (ccMBPT). The use of a dynamic load balancing technique on the NEC SX-3/44 computer in electron correlation calculations is investigated for the calculation of the most demanding energy component in the most accurate of contemporary ab initio studies. An application to the ground state of the nitrogen molecule is described. We also briefly discuss the extent to which the calculation of the dominant corrections to such studies can be rendered computationally tractable by exploiting both the vector processing and parallel processor capabilities of the NEC SX-3/44 computer. (author)

77 FR 20847 - Certain Mobile Electronic Devices Incorporating Haptics; Institution of Investigation Pursuant to...

Science.gov (United States)

2012-04-06

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-834] Certain Mobile Electronic Devices Incorporating Haptics; Institution of Investigation Pursuant to 19 U.S.C. 1337 AGENCY: U.S. International Trade.... International Trade Commission on February 7, 2012, and an amended complaint was filed with the U.S...

Very high channel conductivity in low-defect AlN/GaN high electron mobility transistor structures

International Nuclear Information System (INIS)

Dabiran, A. M.; Wowchak, A. M.; Osinsky, A.; Xie, J.; Hertog, B.; Cui, B.; Chow, P. P.; Look, D. C.

2008-01-01

Low defect AlN/GaN high electron mobility transistor (HEMT) structures, with very high values of electron mobility (>1800 cm 2 /V s) and sheet charge density (>3x10 13 cm -2 ), were grown by rf plasma-assisted molecular beam epitaxy (MBE) on sapphire and SiC, resulting in sheet resistivity values down to ∼100 Ω/□ at room temperature. Fabricated 1.2 μm gate devices showed excellent current-voltage characteristics, including a zero gate saturation current density of ∼1.3 A/mm and a peak transconductance of ∼260 mS/mm. Here, an all MBE growth of optimized AlN/GaN HEMT structures plus the results of thin-film characterizations and device measurements are presented

First International Conference on Electrical, Electronic and Communications Engineering

CERN Document Server

Vyas, Nalinaksh; Sanei, Saeid; Deb, Kalyanmoy

2017-01-01

The book reports on advanced theories and methods in two related engineering fields: electrical and electronic engineering, and communications engineering and computing. It highlights areas of global and growing importance, such as renewable energy, power systems, mobile communications, security and the Internet of Things (IoT). The contributions cover a number of current research issues, including smart grids, photovoltaic systems, wireless power transfer, signal processing, 4G and 5G technologies, IoT applications, mobile cloud computing and many more. Based on the proceedings of the first International Conference on Emerging Trends in Electrical, Electronic and Communications Engineering (ELECOM 2016), held in Voila Bagatelle, Mauritius from November 25 to 27, 2016, the book provides graduate students, researchers and professionals with a snapshot of the state-of-the-art and a source of new ideas for future research and collaborations.

An Adaptive Procedure for Task Scheduling Optimization in Mobile Cloud Computing

Directory of Open Access Journals (Sweden)

Pham Phuoc Hung

2015-01-01

Full Text Available Nowadays, mobile cloud computing (MCC has emerged as a new paradigm which enables offloading computation-intensive, resource-consuming tasks up to a powerful computing platform in cloud, leaving only simple jobs to the capacity-limited thin client devices such as smartphones, tablets, Apple’s iWatch, and Google Glass. However, it still faces many challenges due to inherent problems of thin clients, especially the slow processing and low network connectivity. So far, a number of research studies have been carried out, trying to eliminate these problems, yet few have been found efficient. In this paper, we present an enhanced architecture, taking advantage of collaboration of thin clients and conventional desktop or laptop computers, known as thick clients, particularly aiming at improving cloud access. Additionally, we introduce an innovative genetic approach for task scheduling such that the processing time is minimized, while considering network contention and cloud cost. Our simulation shows that the proposed approach is more cost-effective and achieves better performance compared with others.

Four-dimensional computed tomographic analysis of esophageal mobility during normal respiration

International Nuclear Information System (INIS)

Dieleman, Edith; Senan, Suresh; Vincent, Andrew; Lagerwaard, Frank J.; Slotman, Ben J.; Soernsen de Koste, John R. van

2007-01-01

Background: Chemo-radiotherapy for thoracic tumors can result in high-grade radiation esophagitis. Treatment planning to reduce esophageal irradiation requires organ motion to be accounted for. In this study, esophageal mobility was assessed using four-dimensional computed tomography (4DCT). Methods and Materials: Thoracic 4DCT scans were acquired on a 16-slice CT scanner in 29 patients. The outer esophageal wall was contoured in two extreme phases of respiration in 9 patients with nonesophageal malignancies. The displacement of the center of contour was measured at 2-cm intervals. In 20 additional patients with Stage I lung cancer, the esophagus was contoured in all 10 phases of each 4DCT at five defined anatomic levels. Both approaches were then applied to 4DCT scans of 4 patients who each had two repeat scans performed. A linear mixed effects model was constructed with fixed effects: measurement direction, measurement type, and measurement location along the cranio-caudal axis. Results: Measurement location and direction were significant descriptive parameters (Wald F-tests, p < 0.001), and the interaction term between the two was significant (p = 0.02). Medio-lateral mobility exceeded dorso-ventral mobility in the lower half of the esophagus but was of a similar magnitude in the upper half. Margins that would have incorporated all movement in medio-lateral and dorso-ventral directions were 5 mm proximally, 7 mm and 6 mm respectively in the mid-esophagus, and 9 mm and 8 mm respectively in the distal esophagus. Conclusions: The distal esophagus shows more mobility. Margins for mobility that can encompass all movement were derived for use in treatment planning, particularly for stereotactic radiotherapy

Electronic Patient Reported Outcomes in Paediatric Oncology - Applying Mobile and Near Field Communication Technology.

Science.gov (United States)

Duregger, Katharina; Hayn, Dieter; Nitzlnader, Michael; Kropf, Martin; Falgenhauer, Markus; Ladenstein, Ruth; Schreier, Günter

2016-01-01

Electronic Patient Reported Outcomes (ePRO) gathered using telemonitoring solutions might be a valuable source of information in rare cancer research. The objective of this paper was to develop a concept and implement a prototype for introducing ePRO into the existing neuroblastoma research network by applying Near Field Communication and mobile technology. For physicians, an application was developed for registering patients within the research network and providing patients with an ID card and a PIN for authentication when transmitting telemonitoring data to the Electronic Data Capture system OpenClinica. For patients, a previously developed telemonitoring system was extended by a Simple Object Access Protocol (SOAP) interface for transmitting nine different health parameters and toxicities. The concept was fully implemented on the front-end side. The developed application for physicians was prototypically implemented and the mobile application of the telemonitoring system was successfully connected to OpenClinica. Future work will focus on the implementation of the back-end features.

Mobile computing with special reference to readability task under the impact of vibration, colour combination and gender.

Science.gov (United States)

Mallick, Zulquernain; Siddiquee, Arshad Noor; Haleem, Abid

2008-12-01

The last 20 years have seen a tremendous growth in the field of computing with special reference to mobile computing. Ergonomic issues pertaining to this theme remains unexplored. With special reference to readability in mobile computing, an experimental research was conducted to study the gender effect on human performance under the impact of vibration in a human computer interaction environment. Fourteen subjects (7 males and 7 females) participated in the study. Three independent variables, namely gender, level of vibration and screen text/background colour, were selected for the experimental investigation while the dependent variable was the number of characters read per minute. The data collected were analyzed statistically through an experimental design for repeated measures. Results indicated that gender as an organismic variable, the level of vibration and screen text/background colour revealed statistically significant differences. However, the second order interaction was found to be statistically non-significant. These findings are discussed in light of the previous studies undertaken on the topic.

Mobile agents basic concepts, mobility models, and the tracy toolkit

CERN Document Server

Braun, Peter

2005-01-01

Mobile agents are software nomads that act as your personal representative, working autonomously through networks. They are able to visit network nodes directly using available computing power and are not limited by platform. This emerging field is now poised to become a cornerstone for new Web-based ubiquitous computing environments. Mobile Agents provides a practical introduction to mobile agent technology and surveys the state of the art in mobile agent research. Students and researchers can use the book as an introduction to the concepts and possibilities of this field and as an overview of ongoing research. Developers can use it to identify the capabilities of the technology to decide if mobile agents are the right solution for them. Practioners can also gain hands-on experience in programming mobile agents through exploration of the source code for a complete mobile agent environment available through the companion website.*Summarizes the state of the art in mobile agent research*Identifies the benefits...

Inferring Human Activity in Mobile Devices by Computing Multiple Contexts.

Science.gov (United States)

Chen, Ruizhi; Chu, Tianxing; Liu, Keqiang; Liu, Jingbin; Chen, Yuwei

2015-08-28

This paper introduces a framework for inferring human activities in mobile devices by computing spatial contexts, temporal contexts, spatiotemporal contexts, and user contexts. A spatial context is a significant location that is defined as a geofence, which can be a node associated with a circle, or a polygon; a temporal context contains time-related information that can be e.g., a local time tag, a time difference between geographical locations, or a timespan; a spatiotemporal context is defined as a dwelling length at a particular spatial context; and a user context includes user-related information that can be the user's mobility contexts, environmental contexts, psychological contexts or social contexts. Using the measurements of the built-in sensors and radio signals in mobile devices, we can snapshot a contextual tuple for every second including aforementioned contexts. Giving a contextual tuple, the framework evaluates the posteriori probability of each candidate activity in real-time using a Naïve Bayes classifier. A large dataset containing 710,436 contextual tuples has been recorded for one week from an experiment carried out at Texas A&M University Corpus Christi with three participants. The test results demonstrate that the multi-context solution significantly outperforms the spatial-context-only solution. A classification accuracy of 61.7% is achieved for the spatial-context-only solution, while 88.8% is achieved for the multi-context solution.

[Computer-aided Diagnosis and New Electronic Stethoscope].

Science.gov (United States)

Huang, Mei; Liu, Hongying; Pi, Xitian; Ao, Yilu; Wang, Zi

2017-05-30

Auscultation is an important method in early-diagnosis of cardiovascular disease and respiratory system disease. This paper presents a computer-aided diagnosis of new electronic auscultation system. It has developed an electronic stethoscope based on condenser microphone and the relevant intelligent analysis software. It has implemented many functions that combined with Bluetooth, OLED, SD card storage technologies, such as real-time heart and lung sounds auscultation in three modes, recording and playback, auscultation volume control, wireless transmission. The intelligent analysis software based on PC computer utilizes C# programming language and adopts SQL Server as the background database. It has realized play and waveform display of the auscultation sound. By calculating the heart rate, extracting the characteristic parameters of T1, T2, T12, T11, it can analyze whether the heart sound is normal, and then generate diagnosis report. Finally the auscultation sound and diagnosis report can be sent to mailbox of other doctors, which can carry out remote diagnosis. The whole system has features of fully function, high portability, good user experience, and it is beneficial to promote the use of electronic stethoscope in the hospital, at the same time, the system can also be applied to auscultate teaching and other occasions.

Quasifree electron mobility by the method of partial waves in liquid hydrocarbons and in fluid argon

International Nuclear Information System (INIS)

Vertes, A.

1983-01-01

Applicability of the fluctuation model was tested in the case of n-hexane, n-pentane, c-hexane, 2,2-dimethylbutane, 2,2,4,4-tetramethylpentane, iso-octane, and neopentane. In our model, the quasifree electrons have been assumed to be scattered by the conduction state energy fluctuations of the liquid. These fluctuations are, in turn, described as a consequence of density fluctuations. The scattering potential is supposed to be square well like and the cross section is calculated in terms of partial waves. Averages due to the density fluctuations and the electron kinetic energy distribution are determined numerically. Except for the first three materials, the calculation reproduced the experimental mobilities with reasonable values of the square well radius, which is the only fitting parameters. Further extension of the description concerning the density dependence of the low field mobility of fluid argon has been performed. The estimated fluctuation size as a function of density increases monotonically at the minimum of the mobility in accordance with the monotonic behavior of the isothermal compressibility in the same region

A Mobile Nanoscience and Electron Microscopy Outreach Program

Science.gov (United States)

Coffey, Tonya; Kelley, Kyle

2013-03-01

We have established a mobile nanoscience laboratory outreach program in Western NC that puts scanning electron microscopy (SEM) directly in the hands of K-12 students and the general public. There has been a recent push to develop new active learning materials to educate students at all levels about nanoscience and nanotechnology. Previous projects, such as Bugscope, nanoManipulator, or SPM Live! allowed remote access to advanced microscopies. However, placing SEM directly in schools has not often been possible because the cost and steep learning curve of these technologies were prohibitive, making this project quite novel. We have developed new learning modules for a microscopy outreach experience with a tabletop SEM (Hitachi TM3000). We present here an overview of our outreach and results of the assessment of our program to date.

Affordable mobile robotic platforms for teaching computer science at African universities

OpenAIRE

Gyebi, Ernest; Hanheide, Marc; Cielniak, Grzegorz

2015-01-01

Educational robotics can play a key role in addressing some of the challenges faced by higher education in Africa. One of the major obstacles preventing a wider adoption of initiatives involving educational robotics in this part of the world is lack of robots that would be affordable by African institutions. In this paper, we present a survey and analysis of currently available affordable mobile robots and their suitability for teaching computer science at African universities. To this end, w...

Effects of SiNx on two-dimensional electron gas and current collapse of AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Fan, Ren; Zhi-Biao, Hao; Lei, Wang; Lai, Wang; Hong-Tao, Li; Yi, Luo

2010-01-01

SiN x is commonly used as a passivation material for AlGaN/GaN high electron mobility transistors (HEMTs). In this paper, the effects of SiN x passivation film on both two-dimensional electron gas characteristics and current collapse of AlGaN/GaN HEMTs are investigated. The SiN x films are deposited by high- and low-frequency plasma-enhanced chemical vapour deposition, and they display different strains on the AlGaN/GaN heterostructure, which can explain the experiment results. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Mobile code security

Science.gov (United States)

Ramalingam, Srikumar

2001-11-01

A highly secure mobile agent system is very important for a mobile computing environment. The security issues in mobile agent system comprise protecting mobile hosts from malicious agents, protecting agents from other malicious agents, protecting hosts from other malicious hosts and protecting agents from malicious hosts. Using traditional security mechanisms the first three security problems can be solved. Apart from using trusted hardware, very few approaches exist to protect mobile code from malicious hosts. Some of the approaches to solve this problem are the use of trusted computing, computing with encrypted function, steganography, cryptographic traces, Seal Calculas, etc. This paper focuses on the simulation of some of these existing techniques in the designed mobile language. Some new approaches to solve malicious network problem and agent tampering problem are developed using public key encryption system and steganographic concepts. The approaches are based on encrypting and hiding the partial solutions of the mobile agents. The partial results are stored and the address of the storage is destroyed as the agent moves from one host to another host. This allows only the originator to make use of the partial results. Through these approaches some of the existing problems are solved.

Investigating Students' Perceptions on Mobile Learning Services

Directory of Open Access Journals (Sweden)

Mohammed Amin Almaiah

2014-10-01

Full Text Available M-learning is a form of learning, which has similarities and differences with the electronic learning (e-learning. It is mainly based on the use of the mobile wireless technologies that allow for learners to easily access learning materials anytime he desires and anywhere, whether on campus or off campus. Therefore, this creates a new flexible learning environment in the context of different learning settings. Students' perception of such technology is one of the most important factors for successful adoption of m-learning in the higher education environment. This study is conducted to investigate the perceptions of students in University Malaysia Terengganu (UMT to move towards applying m-learning in their studies by using their mobile devices and to explore their expectations on mobile learning services. A total number of 91 undergraduate students majoring in computer science participated in the study. The findings show that the students have positive perception towards mobile learning and would like to use their mobile devices for both learning and administrative services.

Interactive computer-assisted instruction in acid-base physiology for mobile computer platforms.

Science.gov (United States)

Longmuir, Kenneth J

2014-03-01

In this project, the traditional lecture hall presentation of acid-base physiology in the first-year medical school curriculum was replaced by interactive, computer-assisted instruction designed primarily for the iPad and other mobile computer platforms. Three learning modules were developed, each with ∼20 screens of information, on the subjects of the CO2-bicarbonate buffer system, other body buffer systems, and acid-base disorders. Five clinical case modules were also developed. For the learning modules, the interactive, active learning activities were primarily step-by-step learner control of explanations of complex physiological concepts, usually presented graphically. For the clinical cases, the active learning activities were primarily question-and-answer exercises that related clinical findings to the relevant basic science concepts. The student response was remarkably positive, with the interactive, active learning aspect of the instruction cited as the most important feature. Also, students cited the self-paced instruction, extensive use of interactive graphics, and side-by-side presentation of text and graphics as positive features. Most students reported that it took less time to study the subject matter with this online instruction compared with subject matter presented in the lecture hall. However, the approach to learning was highly examination driven, with most students delaying the study of the subject matter until a few days before the scheduled examination. Wider implementation of active learning computer-assisted instruction will require that instructors present subject matter interactively, that students fully embrace the responsibilities of independent learning, and that institutional administrations measure instructional effort by criteria other than scheduled hours of instruction.

Electron Gun for Computer-controlled Welding of Small Components

Czech Academy of Sciences Publication Activity Database

Dupák, Jan; Vlček, Ivan; Zobač, Martin

2001-01-01

Roč. 62, 2-3 (2001), s. 159-164 ISSN 0042-207X R&D Projects: GA AV ČR IBS2065015 Institutional research plan: CEZ:AV0Z2065902 Keywords : Electron beam-welding machine * Electron gun * Computer- control led beam Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.541, year: 2001

Botulinum toxin detection using AlGaN /GaN high electron mobility transistors

Science.gov (United States)

Wang, Yu-Lin; Chu, B. H.; Chen, K. H.; Chang, C. Y.; Lele, T. P.; Tseng, Y.; Pearton, S. J.; Ramage, J.; Hooten, D.; Dabiran, A.; Chow, P. P.; Ren, F.

2008-12-01

Antibody-functionalized, Au-gated AlGaN /GaN high electron mobility transistors (HEMTs) were used to detect botulinum toxin. The antibody was anchored to the gate area through immobilized thioglycolic acid. The AlGaN /GaN HEMT drain-source current showed a rapid response of less than 5s when the target toxin in a buffer was added to the antibody-immobilized surface. We could detect a range of concentrations from 1to10ng/ml. These results clearly demonstrate the promise of field-deployable electronic biological sensors based on AlGaN /GaN HEMTs for botulinum toxin detection.

Electron Mobilities and Effective Masses in InGaAs/InAlAs HEMT Structures with High In Content

Science.gov (United States)

Yuzeeva, N. A.; Sorokoumova, A. V.; Lunin, R. A.; Oveshnikov, L. N.; Galiev, G. B.; Klimov, E. A.; Lavruchin, D. V.; Kulbachinskii, V. A.

2016-12-01

InxGa_{1-{x}}As/InyAl_{1-{y}}As HEMT structures {δ}-doped by Si were grown by molecular beam epitaxy on InP substrate. We investigated the influence of the In content on the electron mobilities and effective masses in dimensionally quantized subbands. The electron effective masses were determined by the temperature dependence of the amplitude of the Shubnikov-de Haas effect at 1.6 and 4.2 K. We found that the more the In content in quantum well (QW), the less the electron effective masses. The mobilities are higher in HEMT structures with wider and deeper QW. The energy band diagrams were calculated by using Vegard's law for basic parameters. The calculated band diagrams are in a good agreement with the experimental data of photoluminescence spectra.

Comparison between experiment and MCNP simulation for retrospective dosimetry according to the geometry of exposure using electronic components in a mobile phone

International Nuclear Information System (INIS)

Kim, Min Chae; Kim, Hyoungtaek; Lee, Seung Kyu; Chang, Insu; Lee, Jungil; Kim, Jang-Lyul; Kim, Bong-Hwan; Kim, Chan Hyeong

2017-01-01

Many efforts are carrying out for the use of thermoluminescence (TL) and optically stimulated luminescence (OSL) of personal electronic devices (such as mobile phone, USB memory chip etc.) as fortuitous dosimeters in the case of radiation emergency. A correction is required when evaluating the exposure dose to the body using the measured dose to the devices. As a starting point of this purpose, we have studied to evaluate the effects of the position of the electronic device on human body to measure the dose to the electronic device (mobile phone). We evaluated the doses to the mobile phone by using Monte Carlo N-Particle (MCNP) simulations and TL method with resistors and inductors in the mobile phone, and the results were then compared. We have studied to evaluate the effects of the position of mobile phone on human body to measure the dose to the phone with TL method and MCNP simulation method, and then compared. The results obtained by the TL experiments showed excellent agreement with the simulation results. With these results, it is expected that the retrospective estimation of the exposure dose to human body is possible by using the dose to mobile phone measured by TL analysis of resistors and inductors in phone.