WorldWideScience

Sample records for winnebago oshkosh wi

  1. 75 FR 25308 - Environmental Impact Statement: Winnebago County, IL and Rock County, WI

    Science.gov (United States)

    2010-05-07

    ... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Environmental Impact Statement: Winnebago County, IL and Rock County, WI AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice... Nye School Road northwest of Beloit, Rock County, Wisconsin to the interchange of Rockton Road and I...

  2. 77 FR 43517 - Safety Zone; Flying Magazine Air Show, Lake Winnebago, Oshkosh, WI

    Science.gov (United States)

    2012-07-25

    ... and vessels from the hazards associated with an air show over water and associated fireworks display...; then south to 44[deg]00'36'' N, 088[deg]30'16'' W; then west returning to the point of origin (NAD 83... returning to the point of origin (NAD 83). (b) Effective and Enforcement Period. This regulation is...

  3. Final Report Package_Winnebago

    Energy Technology Data Exchange (ETDEWEB)

    Carolyn Stewart, Director, Red Mountain Energy Partners

    2006-10-31

    The Winnebago Tribe of Nebraska energy options study results will be used to advance the Tribe’s near term energy management objectives. The array of energy options identified allows the Tribe to select those activities that best fit its energy strategies, goals and objectives. During the course of the study, Red Mountain analyzed both energy options and energy organizational alternatives suitable for the Tribe, presented findings to the Tribal Council, and made recommendations regarding each. Work products delivered to the Tribe, and provided in the Final Report included: • A matrix of energy management options applicable to the Tribe, which provided descriptions of particular conservation, efficiency, weatherization, and demand management alternatives. The matrix also provided insight about relative costs of the alternatives, cost/benefit efficacy, ease of implementation, resources for implementing, and observations about each. • A matrix of utility service options applicable to the Tribe, describing each of the four alternatives described above. The matrix also provided insight about key benefits of each option, required resources, costs and timeframe for implementation, funding sources and analysis, and key issues for consideration. • Discussion guides prepared for each meeting between the Energy Committee and Council, and the Tribe’s contractor, Red Mountain Energy Partners, which included preliminary analysis and findings. • A Position Description for the Energy Manager position, which was reviewed by the Tribal HR Department, and used by the Tribe to develop a position posting. • A Utility Code designed for Winnebago to use in establishing its Utility Board, and, ultimately, to provide guidance for the Board’s further development. • A project summary book developed to include all key information, deliverables and utility provider data for the project. Winnebago’s growth trends and expansion plans require the Tribe to play a more active

  4. Wind Generation on Winnebago Tribal Lands

    Energy Technology Data Exchange (ETDEWEB)

    Multiple

    2009-09-30

    The Winnebago Wind Energy Study evaluated facility-scale, community-scale and commercial-scale wind development on Winnebago Tribal lands in northeastern Nebraska. The Winnebago Tribe of Nebraska has been pursuing wind development in various forms for nearly ten years. Wind monitoring utilizing loaned met towers from NREL took place during two different periods. From April 2001 to April 2002, a 20-meter met tower monitored wind data at the WinnaVegas Casino on the far eastern edge of the Winnebago reservation in Iowa. In late 2006, a 50-meter tower was installed, and subsequently monitored wind data at the WinnaVegas site from late 2006 through late 2008. Significant challenges with the NREL wind monitoring equipment limited the availability of valid data, but based on the available data, average wind speeds between 13.6 – 14.3 miles were indicated, reflecting a 2+/3- wind class. Based on the anticipated cost of energy produced by a WinnaVegas wind turbine, and the utility policies and rates in place at this time, a WinnaVegas wind project did not appear to make economic sense. However, if substantial grant funding were available for energy equipment at the casino site, and if either Woodbury REC backup rates were lower, or NIPCO was willing to pay more for wind power, a WinnaVegas wind project could be feasible. With funding remaining in the DOE-funded project budget,a number of other possible wind project locations on the Winnebago reservation were considered. in early 2009, a NPPD-owned met tower was installed at a site identified in the study pursuant to a verbal agreement with NPPD which provided for power from any ultimately developed project on the Western Winnebago site to be sold to NPPD. Results from the first seven months of wind monitoring at the Western Winnebago site were as expected at just over 7 meters per second at 50-meter tower height, reflecting Class 4 wind speeds, adequate for commercial development. If wind data collected in the remaining

  5. 75 FR 57287 - Notice of Intent to Repatriate a Cultural Item: Oshkosh Public Museum, Oshkosh, WI

    Science.gov (United States)

    2010-09-20

    ..., after Dennis Lee, son of Gerald Lee, donated the bowl to the museum. The Wisconsin State site report... placed with or near individual human remains at the time of death or later as part of the death rite or...

  6. Oshkosh Logistic Management and Public Relations Responsibilities at NASA Langley

    Science.gov (United States)

    Beck, Danielle

    1995-01-01

    The central focus of my study for the summer of 1995 was to provide logistical support to Margaret Hunt, the logistics manager of the OSHKOSH airshow. In this capacity responsibilities included making arrangements for participants from NASA centers and SBIR companies for their stay in Wisconsin, while visiting the airshow, and managing staff for exhibits and the aerospace theater. A secondary purpose was to serve in other public service capacities by writing news releases, fact sheets, announcements, and articles for the Researcher News.

  7. University of Wisconsin Oshkosh Anaerobic Dry Digestion Facility

    Energy Technology Data Exchange (ETDEWEB)

    Koker, John [Univ. of Wisconsin, Oshkosh, WI (United States); Lizotte, Michael [Univ. of Wisconsin, Oshkosh, WI (United States)

    2017-02-08

    The University of Wisconsin Oshkosh Anaerobic Dry Digestion Facility is a demonstration project that supported the first commercial-scale use in the United States of high solids, static pile technology for anaerobic digestion of organic waste to generate biogas for use in generating electricity and heat. The research adds to the understanding of startup, operation and supply chain issues for anaerobic digester technology. Issues and performance were documented for equipment installation and modifications, feedstock availability and quality, weekly loading and unloading of digestion chambers, chemical composition of biogas produced, and energy production. This facility also demonstrated an urban industrial ecology approach to siting such facilities near sewage treatment plants (to capture and use excess biogas generated by the plants) and organic yard waste collection sites (a source of feedstock).

  8. 77 FR 74170 - Authorization of Production Activity, Foreign-Trade Subzone 107A, Winnebago Industries, Inc...

    Science.gov (United States)

    2012-12-13

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-65-2012] Authorization of Production Activity, Foreign-Trade Subzone 107A, Winnebago Industries, Inc. (Polyurethane Coated Upholstery Fabric), Forest... Forest City and Charles City, Iowa, submitted a notification of proposed production activity to the...

  9. 77 FR 50462 - Notification of Proposed Production Activity; Winnebago Industries, Inc., Subzone 107A...

    Science.gov (United States)

    2012-08-21

    ... July 24, 2012. The subzone currently has authority to produce and warehouse recreational vehicles under.... Production under FTZ procedures for this activity could exempt Winnebago from customs duty payments on the... choose the duty rate during customs entry procedures that applies to motor homes (duty rate 2.5%) for the...

  10. Temporal variation in viral hemorrhagic septicemia virus antibodies in freshwater drum (Aplodinotus grunniens) indicates cyclic transmission in Lake Winnebago, Wisconsin

    Science.gov (United States)

    Wilson-Rothering, Anna; Marcquenski, Susan; Koenigs, Ryan P.; Bruch, Ronald; Kamke, Kendall; Isermann, Daniel A.; Thurman, Andrew; Toohey-Kurth, Kathy; Goldberg, Tony

    2015-01-01

    Viral hemorrhagic septicemia virus (VHSV) is an emerging pathogen that causes mass mortality in multiple fish species. In 2007, the Great Lakes freshwater strain, type IVb, caused a large die-off of freshwater drum (Aplodinotus grunniens) in Lake Winnebago, Wisconsin, USA. To evaluate the persistence and transmission of VHSV, freshwater drum from Lake Winnebago were tested for antibodies to the virus using recently developed virus neutralization (VN) and enzyme-linked immunosorbent (ELISA) assays. Samples were also tested by real-time reverse transcription-PCR (rRT-PCR) to detect viral RNA. Of 548 serum samples tested, 44 (8.03%) were positive by VN (titers ranging from 1:16 to 1:1,024) and 45 (8.21%) were positive by ELISA, including 7 fish positive by both assays. Antibody prevalence increased with age and was higher in one northwestern area of Lake Winnebago than in other areas. Of 3,864 tissues sampled from 551 fish, 1 spleen and 1 kidney sample from a single adult female fish collected in the spring of 2012 tested positive for VHSV by rRT-PCR, and serum from the same fish tested positive by VN and ELISA. These results suggest that VHSV persists and viral transmission may be active in Lake Winnebago even in years following outbreaks and that wild fish may survive VHSV infection and maintain detectable antibody titers while harboring viral RNA. Influxes of immunologically naive juvenile fish through recruitment may reduce herd immunity, allow VHSV to persist, and drive superannual cycles of transmission that may sporadically manifest as fish kills.

  11. WiMAX-WiFi convergence with OFDM bridge

    Science.gov (United States)

    Al-Sherbaz, Ali; Adams, Chris; Jassim, Sabah

    2009-05-01

    Nowadays, Wireless and mobile communications technologies are the most important areas, which are rapidly expanding either in horizontal or vertical directions. WiMAX is trying to compete with WiFi in coverage and data rate, while the inexpensive WiFi still very popular in both personal and business use. Efficient bandwidth usage, Multi-Standard convergence and Wireless Mesh Networks (WMN) are the main vertical tends in the wireless world. WiMAX-WiFi convergence as an ideal technology that provides the best of both worlds: WiMAX new features and the low cost of the WiFi. In order to create a heterogeneous network environment, differences between the two technologies have been investigated and resolved. In the Multi-Carrier WiMAX-WiFi Convergence, the mismatch between the fixed WiMAXOFDM (Nfft=256) and the WiFi-OFDM (Nfft=64) has been confirmed as a physical layer issue that will never be solved as MAC layer problem; therefore the current proposal is how to build what we called the "Convergence-Bridge". This bridge is like an extra thin layer, which is responsible for harmonizing the mismatch. For the WiFi-OFDM physical layer, the paper has selected the IEEE 802.11n OFDM standard while it is being developed. The proposal does not suggest changing the standard itself but modifying some functions to be configurable. The IEEE 802.11 standard has fixed the configurations for WiFi mode only, while our proposal is to set up these functions for WiFi and WiMAX modes.

  12. KiWi Vision

    DEFF Research Database (Denmark)

    Schaffert, Sebastian; Bry, Francois; Dolog, Peter

    This deliverable describes the common vision of the KiWi project, ranging from motivation over use cases and usage scenarios to user interaction, system architecture and technologies, and the research that is performed as part of the project. The deliverable is intended for a wide audience to give...

  13. DIY WiFi

    CERN Document Server

    Jungnickel, Katrina

    2013-01-01

    Who makes WiFi?Why do different makers matter?What do barbeques and backyards have to do with the internet?This book explores how WiFi is made from the ground up, or in this case from the backyard out. Forged around barbeques, made of found, adapted and off-the-shelf materials and installed in ordinary domestic spaces, this book documents the collective work of individuals committed to making 'Ournet not the internet'.Drawing on rich ethnographic material, Jungnickel's research on community WiFi networking provides an overdue account of the innovative digital cultures and practices of ordinary people making extra-ordinary things. What make-do methods, mods and tales of resourceful ingenuity permit is another way of seeing how technologies come into being. It brings to life an Australian version of WiFi, enriching global studies of wireless technology by signalling the potential of comparative studies. Critically, the book presents the first sustained study of homebrew high-tech backyard technologists who imbu...

  14. WiFi and WiMAX Secure Deployments

    Directory of Open Access Journals (Sweden)

    Panagiotis Trimintzios

    2010-01-01

    Full Text Available Wireless Broadband offers incredibly fast, “always on” Internet similar to ADSL and sets the user free from the fixed access areas. In order to achieve these features standardisation was achieved for Wireless LAN (WLANs and Wireless Metropolitan Area Networks (WMANs with the advent of IEEE802.11 and IEEE802.16 family of standards, respectively. One serious concern in the rapidly developing wireless networking market has been the security of the deployments since the information is delivered freely in the air and therefore privacy and integrity of the transmitted information, along with the user-authentication procedures, become a very important issue. In this article, we present the security characteristics for the WiFi and the WiMAX networks. We thoroughly present the security mechanisms along with a threat analysis for both IEEE 802.11 and the 802.16 as well as their amendments. We summarise in a comparative manner the security characteristics and the possible residual threats for both standards. Finally focus on the necessary actions and configurations that are needed in order to deploy WiFi and WiMAX with increased levels of security and privacy.

  15. Wi-Fi/WiGig Coordination for Optimal WiGig Concurrent Transmissions in Random Access Scenario

    OpenAIRE

    Mohamed, Ehab Mahmoud; Sakaguchi, Kei; Sampei, Seiichi

    2016-01-01

    Wireless Gigabit (WiGig) access points (APs) using 60 GHz unlicensed frequency band are considered as key enablers for future Gbps WLANs. Due to its short range transmission with high susceptibility to path blocking, a multiple number of WiGig APs should be installed to fully cover a typical target environment. However, using autonomously operated WiGig APs with IEEE 802.11ad DCF, the exhaustive search analog beamforming and the maximum received power based autonomous users association preven...

  16. Winnebago Tribe Solar Project

    Energy Technology Data Exchange (ETDEWEB)

    Nieman, Autumn [Winnebago Tribe of Nebraska Solar Project (United States)

    2016-02-26

    The strategy of the Solar Project was to reduce fuel use within two years by a roof mounted photovoltaic system. The police/fire building is completely powered by electricity. The renewable energy system we have selected has a power capacity of 23kW and the ability to export 44.3 MWh. We anticipate 32.55% kWh energy savings, an excess of the required 30% reduction, in the building’s total fuel use based on the most current 12 months of data (2012). The solar electric system is a grid-tie, ballast mounted on a flat roof over the police/fire station. The solar electric system includes 280 Watt modules for a nominal total of 22.80 kW. Approximately 84 modules are ballast mounted to the flat roof facing south.

  17. Campus Area Network Wi-Fi Security

    Directory of Open Access Journals (Sweden)

    Arjun K. Pillay

    2017-07-01

    Full Text Available Wireless connectivity devices such as mobile phones and laptops are being increasingly used by University students to access learning resources on campus networks and the Internet. Each of the mobile devices offers security protocols for connection to a Wi-Fi router. This paper presents an overview of Wi-Fi security and recommendations in relation to free Wi-Fi service at The University of Fiji.

  18. WIRELESS FIDELITY (Wi-Fi) BROADBAND NETWORK ...

    African Journals Online (AJOL)

    ES Obe

    categorized into two types: fixed and mobile wireless. The broadband fixed wireless network technologies .... 3.0 WIRELESS FIDELITYF (Wi-Fi). NETWORK IMPLEMENTATION. A Wi-Fi enabled device such as a PC, game .... Amateur radio, video senders, and cordless phones, can cause significant additional interference.

  19. LTE OFFLOADING THROUGH WiFi NETWORKS

    Directory of Open Access Journals (Sweden)

    A. N. Steputin

    2015-11-01

    Full Text Available The subject of the article is Wi-Fi offloading of LTE networks as one of the methods for solving a problem of the lack of availability of network resources in the future. Comparison of mobile networks offloading technologies, such as femtocells, Small Cells and Wi-Fi, is given. Architecture of cooperative LTE+Wi-Fi network including both new network components and new functions for standard LTE network components is presented as well as interaction between components. Special attention is paid to the usage of mobile IP protocols providing connection to the LTE Core both by trusted and untrusted Wi-Fi access. Evaluation of implementation effectiveness and prospective of the technology is given. The relation between amounts of users reconnected to Wi-Fi, data rate of LTE network and amount of access points are submitted as a part of the simulation of user’s equipment transition process from LTE to Wi-Fi network. A conclusion based on the research is made that stepwise phase-in of this technology enables to solve the problem of mobile network resources shortage in metropolises due to permanent traffic growth. It is presented that access points addition and transference of the customers to Wi-Fi network significantly reduce the overload on the base station herewith it increases some data rate with preservation of quality of provided services.

  20. WiMax network planning and optimization

    CERN Document Server

    Zhang, Yan

    2009-01-01

    This book offers a comprehensive explanation on how to dimension, plan, and optimize WiMAX networks. The first part of the text introduces WiMAX networks architecture, physical layer, standard, protocols, security mechanisms, and highly related radio access technologies. It covers system framework, topology, capacity, mobility management, handoff management, congestion control, medium access control (MAC), scheduling, Quality of Service (QoS), and WiMAX mesh networks and security. Enabling easy understanding of key concepts and technologies, the second part presents practical examples and illu

  1. Coexistence of WiFi and WiMAX systems based on PS-request protocols.

    Science.gov (United States)

    Kim, Jongwoo; Park, Suwon; Rhee, Seung Hyong; Choi, Yong-Hoon; Chung, Young-uk; Hwang, Ho Young

    2011-01-01

    We introduce both the coexistence zone within the WiMAX frame structure and a PS-Request protocol for the coexistence of WiFi and WiMAX systems sharing a frequency band. Because we know that the PS-Request protocol has drawbacks, we propose a revised PS-Request protocol to improve the performance. Two PS-Request protocols are based on the time division operation (TDO) of WiFi system and WiMAX system to avoid the mutual interference, and use the vestigial power management (PwrMgt) bit within the Frame Control field of the frames transmitted by a WiFi AP. The performance of the revised PS-Request protocol is evaluated by computer simulation, and compared to those of the cases without a coexistence protocol and to the original PS-Request protocol.

  2. Coexistence of WiFi and WiMAX Systems Based on PS-Request Protocols†

    Science.gov (United States)

    Kim, Jongwoo; Park, Suwon; Rhee, Seung Hyong; Choi, Yong-Hoon; Chung, Young-uk; Hwang, Ho Young

    2011-01-01

    We introduce both the coexistence zone within the WiMAX frame structure and a PS-Request protocol for the coexistence of WiFi and WiMAX systems sharing a frequency band. Because we know that the PS-Request protocol has drawbacks, we propose a revised PS-Request protocol to improve the performance. Two PS-Request protocols are based on the time division operation (TDO) of WiFi system and WiMAX system to avoid the mutual interference, and use the vestigial power management (PwrMgt) bit within the Frame Control field of the frames transmitted by a WiFi AP. The performance of the revised PS-Request protocol is evaluated by computer simulation, and compared to those of the cases without a coexistence protocol and to the original PS-Request protocol. PMID:22163721

  3. Joint Light Tactical Vehicle (JLTV): Background and Issues for Congress

    Science.gov (United States)

    2017-01-10

    Lockheed Martin Corporation (Grand Prairie, TX); and Oshkosh Corporation (Oshkosh, WI). On September 3, 2013, the Army began JLTV testing at Aberdeen... body protection as the Mine-Resistant, Ambush-Protected All- Terrain Vehicle (M-ATV). DOD had planned to award two contracts for the EMD phase, which...LLC (South Bend, IN); Lockheed Martin Corporation (Grand Prairie, TX); and Oshkosh Corporation (Oshkosh, WI). The period of performance was for 27

  4. WiFi Assisted Multi-WiGig AP Coordination for Future Multi-Gbps WLANs

    OpenAIRE

    Mohamed, Ehab Mahmoud; Kusano, Hideyuki; Sakaguchi, Kei; Sampei, Seiichi

    2015-01-01

    Wireless Gigabit (WiGig) access points (APs) using 60 GHz unlicensed frequency band are considered as key enablers for future Gbps wireless local area networks (WLANs). Exhaustive search analog beamforming (BF) is mainly used with WiGig transmissions to overcome channel propagation loss and accomplish high rate data transmissions. Due to its short range transmission with high susceptibility to path blocking, a multiple number of WiGig APs should be installed to fully cover a typical target en...

  5. Indoor Positioning using Wi-Fi

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Krarup, Mads Vering; Stisen, Allan

    The past decade has witnessed substantial research on methods for indoor Wi-Fi positioning. While much effort has gone into achieving high positioning accuracy and easing fingerprint collection, it is our contention that the general problem is not sufficiently well understood, thus preventing...... deployments and their usage by applications to become more widespread. Based on our own and published experiences on indoor Wi-Fi positioning deployments, we hypothesize the following: Current indoor Wi-Fi positioning systems and their utilization in applications are hampered by the lack of understanding...... of the requirements present in the real-world deployments. In this paper, we report findings from qualitatively studying organisational requirements for indoor Wi-Fi positioning. The studied cases and deployments cover both company and public-sector settings and the deployment and evaluation of several types...

  6. Eesti graafikud Krakówi triennaalil

    Index Scriptorium Estoniae

    2009-01-01

    16. septembril Poolas avatud Krakówi rahvusvahelise graafikatriennaali peanäitusel ja satelliitnäitustel esindavad Eestit Eve Kask, Ülle Marks, Benjamin Vasserman, Tiiu Prisko, Mati Veermets, Evi Tihemets

  7. WiMAX technology and network evolution

    CERN Document Server

    Etemad, Kamran

    2010-01-01

    WiMAX, the Worldwide Interoperability for Microwave Access, represents a paradigm shift in telecommunications technology. It offers the promise of cheaper, smaller, and simpler technology compared to existing broadband options such as DSL, cable, fiber, and 3G wireless.

  8. Integrating free-space optical communication links with existing WiFi (WiFO) network

    Science.gov (United States)

    Liverman, S.; Wang, Q.; Chu, Y.; Duong, T.; Nguyen-Huu, D.; Wang, S.; Nguyen, T.; Wang, A. X.

    2016-02-01

    Recently, free-space optical (FSO) systems have generated great interest due to their large bandwidth potential and a line-of-sight physical layer of protection. In this paper, we propose WiFO, a novel hybrid system, FSO downlink and WiFi uplink, which will integrate currently available WiFi infrastructure with inexpensive infrared light emitting diodes. This system takes full advantage of the mobility inherent in WiFi networks while increasing the downlink bandwidth available to each end user. We report the results of our preliminary investigation that show the capabilities of our prototype design in terms of bandwidth, bit error rates, delays and transmission distances.

  9. How much can Wi-Fi offload?

    DEFF Research Database (Denmark)

    Hu, Liang; Coletti, Claudio; Nguyen, Huan Cong

    2012-01-01

    This paper is envisaged to provide a first quantitative study on how much indoor deployed Wi-Fi can offload the operator’s 3G HSPA macro cellular networks in a real largescale dense-urban scenario. Wi-Fi has been perceived as a costeffective mean of adding wireless capacity by leveraging low......-cost access points and unlicensed spectrum. However, the quantitative offloading gain that Wi-Fi can achieve is still unknown. We studied the Wi-Fi offloading gain as a function of access point density, where it is shown that 10 access points/km2 can already boost average user throughput by 300% and the gain...... increases linearly proportional to the access point density. Indoor Wi-Fi deployment also significantly reduces the number of users in outage, especially for indoor area. A user is considered to be in outage if they have a user throughput less than 512 kbps. We also propose three Wi-Fi deployment algorithms...

  10. WiMax taking wireless to the max

    CERN Document Server

    Pareek, Deepak

    2006-01-01

    With market value expected to reach 5 billion by 2007 and the endorsement of some of the biggest names in telecommunications, World Interoperability for Microwave Access (WiMAX) is poised to change the broadband wireless landscape. But how much of WiMAX's touted potential is merely hype? Now that several pre-WiMAX networks have been deployed, what are the operators saying about QoS and ROI? How and when will device manufacturers integrate WiMAX into their products? What is the business case for using WiMAX rather than any number of other established wireless alternatives?WiMAX: Taking Wireless

  11. Personalization Component for KiWi Framework

    DEFF Research Database (Denmark)

    Durao, Frederico; Xu, Guandong; Kotowski, Jakub

    2010-01-01

    . The personalization component is responsible for addressing and delivering information to individuals regarding their roles and preferences, explicitly or implicitly inferred from their activities in the system. Personalization is a essential for KiWi since this in a multi-user environment and individuals has......In this report we present the personalization component implemented for KiWi addressing diverse aspects such as motivation scenarios, configuration management, formal models, implementations and some real case scenarios on how personalization can be applied to support software project management...... different interests and needs when using the system....

  12. ESP8266 WI-FI MODULE FOR MONITORING SYSTEM APPLICATION

    OpenAIRE

    Tae-Gue Oh; Chung-Hyuk Yim; Gyu-Sik Kim

    2017-01-01

    The ESP8266 Wi-Fi module is a self-contained system-on-chip (SOC) with integrated TCP/IP protocol stacks that can give any microcontroller access to a Wi-Fi network. In this paper, the interface between the ESP8266 Wi-Fi module and arduino MCU is studied for monitoring system application. Through some experimental studies, we believe that the ESP8266 Wi-Fi module is very useful for monitoring system application.

  13. Wi-Fi Versus Cell Phone Service

    Science.gov (United States)

    Roberts, Gary

    2006-01-01

    Regardless of whether cell phones remain the dominant platform or Wi-Fi becomes the prevalent platform, there are some things that libraries can do to improve patron service in light of evolving expectations, behaviors, and tools. People today are more nomadic, which leads to the very real possibility of having to deliver content not just to the…

  14. SeaWiFS Third Anniversary Global Biosphere

    Science.gov (United States)

    2002-01-01

    September 18,2000 is the third anniversary of the start of regular SeaWiFS operations of this remarkable planet called Earth. This SeaWiFS image is of the Global Biosphere depicting the ocean's long-term average phytoplankton chlorophyll concentration acquired between September 1997 and August 2000 combined with the SeaWiFS-derived Normalized Difference Vegetation Index (NDVI) over land during July 2000.

  15. The WiLI benchmark dataset for written language identification

    OpenAIRE

    Thoma, Martin

    2018-01-01

    This paper describes the WiLI-2018 benchmark dataset for monolingual written natural language identification. WiLI-2018 is a publicly available, free of charge dataset of short text extracts from Wikipedia. It contains 1000 paragraphs of 235 languages, totaling in 23500 paragraphs. WiLI is a classification dataset: Given an unknown paragraph written in one dominant language, it has to be decided which language it is.

  16. Mapping of MAC Address with Moving WiFi Scanner

    Directory of Open Access Journals (Sweden)

    Arief Hidayat

    2017-10-01

    Full Text Available Recently, Wifi is one of the most useful technologies that can be used for detecting and counting MAC Address. This paper described using of WiFi scanner which carried out seven times circulated the bus. The method used WiFi and GPS are to counting MAC address as raw data from the pedestrian smartphone, bus passenger or WiFi devices near from the bus as long as the bus going around the route. There are seven processes to make map WiFi data.

  17. Sharing your urban residential WiFi (UR-WiFi)

    NARCIS (Netherlands)

    Kawade, Santosh; van Bloem, J.W.H.; Abhayawardhana, V.S.; Wisely, D.

    2006-01-01

    Cheap and ubiquitous broadband wireless access is what most of the operators are aiming for. This paper analyses an innovative proposal to extend the traditional fixed coverage offered by residential broadband into an urban wireless coverage using urban residential wireless fidelity (UR-WiFi)

  18. WiFi networks and malware epidemiology.

    Science.gov (United States)

    Hu, Hao; Myers, Steven; Colizza, Vittoria; Vespignani, Alessandro

    2009-02-03

    In densely populated urban areas WiFi routers form a tightly interconnected proximity network that can be exploited as a substrate for the spreading of malware able to launch massive fraudulent attacks. In this article, we consider several scenarios for the deployment of malware that spreads over the wireless channel of major urban areas in the US. We develop an epidemiological model that takes into consideration prevalent security flaws on these routers. The spread of such a contagion is simulated on real-world data for georeferenced wireless routers. We uncover a major weakness of WiFi networks in that most of the simulated scenarios show tens of thousands of routers infected in as little as 2 weeks, with the majority of the infections occurring in the first 24-48 h. We indicate possible containment and prevention measures and provide computational estimates for the rate of encrypted routers that would stop the spreading of the epidemics by placing the system below the percolation threshold.

  19. Wi-Fi Service enhancement at CERN

    Science.gov (United States)

    Ducret, V.; Sosnowski, A.; Gonzalez Caballero, B.; Barrand, Q.

    2017-10-01

    Since the early 2000’s, the number of mobile devices connected to CERN’s internal network has increased from just a handful to well over 10,000. Wireless access is no longer simply “nice to have” or just for conference and meeting rooms; support for mobility is expected by most, if not all, of the CERN community. In this context, a full renewal of the CERN Wi-Fi network has been launched to deliver a state-of-the-art campus-wide Wi-Fi Infrastructure. We aim to deliver, in more than 200 office buildings with a surface area of over 400,000m2 and including many high-priority and high-occupation zones, an end-user experience comparable, for most applications, to a wired connection and with seamless mobility support. We describe here the studies and tests performed at CERN to ensure the solution we are deploying can meet these goals as well as delivering a single, simple, flexible and open management platform.

  20. WiFi networks and malware epidemiology

    Science.gov (United States)

    Hu, Hao; Myers, Steven; Colizza, Vittoria; Vespignani, Alessandro

    2009-01-01

    In densely populated urban areas WiFi routers form a tightly interconnected proximity network that can be exploited as a substrate for the spreading of malware able to launch massive fraudulent attacks. In this article, we consider several scenarios for the deployment of malware that spreads over the wireless channel of major urban areas in the US. We develop an epidemiological model that takes into consideration prevalent security flaws on these routers. The spread of such a contagion is simulated on real-world data for georeferenced wireless routers. We uncover a major weakness of WiFi networks in that most of the simulated scenarios show tens of thousands of routers infected in as little as 2 weeks, with the majority of the infections occurring in the first 24–48 h. We indicate possible containment and prevention measures and provide computational estimates for the rate of encrypted routers that would stop the spreading of the epidemics by placing the system below the percolation threshold. PMID:19171909

  1. Eduroam: Secure WiFi roaming for education and research

    CSIR Research Space (South Africa)

    Miteff, S

    2012-10-01

    Full Text Available ? No security ? ?Hotel WiFi? - captive portal ? WPA2-Personal ? Don't permit guest access Pillars of information security ? Confidentiality ? Integrity ? Availability ? Did you just DoS yourself? ? We need a better plan The better plan: WiFi roaming...

  2. Wireless Fidelity (Wi-Fi) Broadband Network Technology: An ...

    African Journals Online (AJOL)

    Wireless Fidelity (Wi-Fi) broadband network technology has made tremendous impact in the growth of broadband wireless networks. There exists today several Wi-Fi access points that allow employees, partners and customers to access corporate data from almost anywhere and anytime. Wireless broadband networks are ...

  3. 75 FR 30300 - Drawbridge Operation Regulations; Root River, Racine, WI

    Science.gov (United States)

    2010-06-01

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 [Docket No. USCG-2010-0414] Drawbridge Operation Regulations; Root River, Racine, WI AGENCY: Coast Guard, DHS. ACTION: Notice of temporary... Bridge at Mile 0.53 over the Root River, at Racine, WI. This deviation will temporarily change the...

  4. Wi-Fi Coexistence with Duty Cycled LTE-U

    Directory of Open Access Journals (Sweden)

    Yimin Pang

    2017-01-01

    Full Text Available Coexistence of Wi-Fi and LTE-Unlicensed (LTE-U technologies has drawn significant concern in industry. In this paper, we investigate the Wi-Fi performance in the presence of duty cycle based LTE-U transmission on the same channel. More specifically, one LTE-U cell and one Wi-Fi basic service set (BSS coexist by allowing LTE-U devices to transmit their signals only in predetermined duty cycles. Wi-Fi stations, on the other hand, simply contend the shared channel using the distributed coordination function (DCF protocol without cooperation with the LTE-U system or prior knowledge about the duty cycle period or duty cycle of LTE-U transmission. We define the fairness of the above scheme as the difference between Wi-Fi performance loss ratio (considering a defined reference performance and the LTE-U duty cycle (or function of LTE-U duty cycle. Depending on the interference to noise ratio (INR being above or below −62 dbm, we classify the LTE-U interference as strong or weak and establish mathematical models accordingly. The average throughput and average service time of Wi-Fi are both formulated as functions of Wi-Fi and LTE-U system parameters using probability theory. Lastly, we use the Monte Carlo analysis to demonstrate the fairness of Wi-Fi and LTE-U air time sharing.

  5. Tracking Human Mobility Using WiFi Signals

    DEFF Research Database (Denmark)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location...... to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population....... These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking....

  6. Challenges for Social Sensing using WiFi Signals

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Nurmi, Petteri

    2012-01-01

    Smartphones are an attractive option for social sensing due to their widespread market penetration rate and advanced sensing capabilities. Enabling social sensing on smartphones would require techniques that can accurately detect and characterize physical proximity, an important prerequisite...... for the capture of more complex social phenomena. One of the most promising modalities for this purpose is WiFi, as it works both indoors and outdoors, and as WiFi signal environment tends to contain significant spatial variation. A challenge in using WiFi, however, is that the signals are affected by many noise...... sources, such as fast fading, body attenuation, hardware differences and varying access points densities. In this paper we review existing work on using WiFi for social sensing and outline challenges that have to be addressed to utilize WiFi at large for social sensing....

  7. Tracking Human Mobility Using WiFi Signals.

    Science.gov (United States)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu; Lehmann, Sune

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population. These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking.

  8. Holography of Wi-fi Radiation

    Science.gov (United States)

    Holl, Philipp M.; Reinhard, Friedemann

    2017-05-01

    Wireless data transmission systems such as wi-fi or Bluetooth emit coherent light—electromagnetic waves with a precisely known amplitude and phase. Propagating in space, this radiation forms a hologram—a two-dimensional wave front encoding a three-dimensional view of all objects traversed by the light beam. Here we demonstrate a scheme to record this hologram in a phase-coherent fashion across a meter-sized imaging region. We recover three-dimensional views of objects and emitters by feeding the resulting data into digital reconstruction algorithms. Employing a digital implementation of dark-field propagation to suppress multipath reflection, we significantly enhance the quality of the resulting images. We numerically simulate the hologram of a 10-m-sized building, finding that both localization of emitters and 3D tomography of absorptive objects could be feasible by this technique.

  9. Tracking Human Mobility Using WiFi Signals

    DEFF Research Database (Denmark)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu

    2015-01-01

    We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign locatio....... These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking.......We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location...... to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population...

  10. Community Based Networks and 5G Wi-Fi

    DEFF Research Database (Denmark)

    Williams, Idongesit

    2018-01-01

    This paper argues on why Community Based Networks should be recognized as potential 5G providers using 5G Wi-Fi. The argument is hinged on findings in a research to understand why Community Based Networks deploy telecom and Broadband infrastructure. The study was a qualitative study carried out...... inductively using Grounded Theory. Six cases were investigated. Two Community Based Network Mobilization Models were identified. The findings indicate that 5G Wi-Fi deployment by Community Based Networks is possible if policy initiatives and the 5G Wi-Fi standards are developed to facilitate the causal...

  11. SeaWiFS_L3b_SCWI_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  12. SeaWiFS_L3b_SCSU_PAR

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  13. SeaWiFS_L3b_DAY_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  14. SeaWiFS_L3b_SNSP_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  15. SeaWiFS_L3b_CU_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  16. SeaWiFS_L3b_SNWI_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  17. SeaWiFS_L3b_DAY_LAND

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  18. SeaWiFS_L3b_CU_CDOM

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  19. SeaWiFS_L3b_SCAU_LAND

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  20. SeaWiFS_L3b_SCSU_CDOM

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  1. SeaWiFS_L3b_SCWI_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  2. SeaWiFS_L3b_MC_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  3. SeaWiFS_L3b_CU_PIC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  4. SeaWiFS_L3b_SCWI_LAND

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  5. SeaWiFS_L3b_SNAU_CDOM

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  6. SeaWiFS_L3b_SCSP_CDOM

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  7. SeaWiFS_L3b_DAY_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  8. SeaWiFS_L3b_SNWI_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  9. SeaWiFS_L3b_SCSP_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  10. SeaWiFS_L3b_DAY_CDOM

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  11. SeaWiFS_L3b_WC_PIC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  12. SeaWiFS_L3b_WC_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  13. SeaWiFS_L3b_SNWI_LAND

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  14. SeaWiFS_L3b_SCSU_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  15. SeaWiFS_L3b_SCSP_PAR

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  16. SeaWiFS_L3b_SCSU_PIC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  17. SeaWiFS_L3b_MO_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  18. SeaWiFS_L3b_SCSP_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  19. SeaWiFS_L3b_MC_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  20. SeaWiFS_L3b_MO_PIC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  1. SeaWiFS_L3b_MC_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  2. SeaWiFS_L3b_SNAU_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  3. SeaWiFS_L3b_SNSP_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  4. 76 FR 35831 - Television Broadcasting Services; Eau Claire, WI

    Science.gov (United States)

    2011-06-20

    ...] Television Broadcasting Services; Eau Claire, WI AGENCY: Federal Communications Commission. ACTION: Proposed rule. SUMMARY: The Commission has before it a petition for rulemaking filed by Gray Television Licensee... 73 Television, Television broadcasting. Federal Communications Commission. Barbara A. Kreisman, Chief...

  5. SeaWiFS_L3b_SNWI_CDOM

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  6. SeaWiFS_L3b_CU_LAND

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  7. SeaWiFS_L3b_MO_PAR

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  8. WI Biodiesel Blending Progream Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Redmond, Maria E; Levy, Megan M

    2013-04-01

    The Wisconsin State Energy Office's (SEO) primary mission is to implement cost effective, reliable, balanced, and environmentally friendly clean energy projects. To support this mission the Wisconsin Biodiesel Blending Program was created to financially support the installation infrastructure necessary to directly sustain biodiesel blending and distribution at petroleum terminal facilities throughout Wisconsin. The SEO secured a federal directed award of $600,000 over 2.25 years. With these funds, the SEO supported the construction of inline biodiesel blending facilities at two petroleum terminals in Wisconsin. The Federal funding provided through the state provided a little less than half of the necessary investment to construct the terminals, with the balance put forth by the partners. Wisconsin is now home to two new biodiesel blending terminals. Fusion Renewables on Jones Island (in the City of Milwaukee) will offer a B100 blend to both bulk and retail customers. CITGO is currently providing a B5 blend to all customers at their Granville, WI terminal north of the City of Milwaukee.

  9. Novel Approaches to Enhance Mobile WiMAX Security

    Directory of Open Access Journals (Sweden)

    Taeshik Shon

    2010-01-01

    Full Text Available The IEEE 802.16 Working Group on Broadband Wireless Access Standards released IEEE 802.16-2004 which is a standardized technology for supporting broadband and wireless communication with fixed and nomadic access. After the IEEE 802.16-2004 standard, a new advanced and revised standard was released as the IEEE 802.16e-2005 amendment which is foundation of Mobile WiMAX network supporting handover and roaming capabilities. In the area of security aspects, compared to IEEE 802.16-2004, IEEE 802.16e, called Mobile WiMAX, adopts improved security architecture—PKMv2 which includes EAP authentication, AES-based authenticated encryption, and CMAC or HMAC message protection. However, there is no guarantee that PKMv2-based Mobile WiMAX network will not have security flaws. In this paper, we investigate the current Mobile WiMAX security architecture focusing mainly on pointing out new security vulnerabilities such as a disclosure of security context in network entry, a lack of secure communication in network domain, and a necessity of efficient handover supporting mutual authentication. Based on the investigation results, we propose a novel Mobile WiMAX security architecture, called RObust and Secure MobilE WiMAX (ROSMEX, to prevent the new security vulnerabilities.

  10. The Audacity of Fiber-Wireless (FiWi) Networks

    Science.gov (United States)

    Maier, Martin; Ghazisaidi, Navid; Reisslein, Martin

    A plethora of enabling optical and wireless technologies have been emerging that can be used to build future-proof bimodal fiber-wireless (FiWi) broadband access networks. After overviewing key enabling radio-over-fiber (RoF) and radio-and-fiber (R&F) technologies and briefly surveying the state of the art of FiWi networks, we introduce an Ethernet-based access-metro FiWi network, called SuperMAN, that integrates next-generation WiFi and WiMAX networks with WDM-enhanced EPON and RPR networks. Throughout the paper we pay close attention to the technical challenges and opportunities of FiWi networks, but also elaborate on their societal benefits and potential to shift the current research focus from optical-wireless networking to the exploitation of personal and in-home computing facilities to create new unforeseen services and applications as we are about to enter the Petabyte age.

  11. Wi-Fi/MARG Integration for Indoor Pedestrian Localization.

    Science.gov (United States)

    Tian, Zengshan; Jin, Yue; Zhou, Mu; Wu, Zipeng; Li, Ze

    2016-12-10

    With the wide deployment of Wi-Fi networks, Wi-Fi based indoor localization systems that are deployed without any special hardware have caught significant attention and have become a currently practical technology. At the same time, the Magnetic, Angular Rate, and Gravity (MARG) sensors installed in commercial mobile devices can achieve highly-accurate localization in short time. Based on this, we design a novel indoor localization system by using built-in MARG sensors and a Wi-Fi module. The innovative contributions of this paper include the enhanced Pedestrian Dead Reckoning (PDR) and Wi-Fi localization approaches, and an Extended Kalman Particle Filter (EKPF) based fusion algorithm. A new Wi-Fi/MARG indoor localization system, including an Android based mobile client, a Web page for remote control, and a location server, is developed for real-time indoor pedestrian localization. The extensive experimental results show that the proposed system is featured with better localization performance, with the average error 0.85 m, than the one achieved by using the Wi-Fi module or MARG sensors solely.

  12. Wi-Fi/MARG Integration for Indoor Pedestrian Localization

    Directory of Open Access Journals (Sweden)

    Zengshan Tian

    2016-12-01

    Full Text Available With the wide deployment of Wi-Fi networks, Wi-Fi based indoor localization systems that are deployed without any special hardware have caught significant attention and have become a currently practical technology. At the same time, the Magnetic, Angular Rate, and Gravity (MARG sensors installed in commercial mobile devices can achieve highly-accurate localization in short time. Based on this, we design a novel indoor localization system by using built-in MARG sensors and a Wi-Fi module. The innovative contributions of this paper include the enhanced Pedestrian Dead Reckoning (PDR and Wi-Fi localization approaches, and an Extended Kalman Particle Filter (EKPF based fusion algorithm. A new Wi-Fi/MARG indoor localization system, including an Android based mobile client, a Web page for remote control, and a location server, is developed for real-time indoor pedestrian localization. The extensive experimental results show that the proposed system is featured with better localization performance, with the average error 0.85 m, than the one achieved by using the Wi-Fi module or MARG sensors solely.

  13. Wi-Fi is an important threat to human health.

    Science.gov (United States)

    Pall, Martin L

    2018-03-21

    Repeated Wi-Fi studies show that Wi-Fi causes oxidative stress, sperm/testicular damage, neuropsychiatric effects including EEG changes, apoptosis, cellular DNA damage, endocrine changes, and calcium overload. Each of these effects are also caused by exposures to other microwave frequency EMFs, with each such effect being documented in from 10 to 16 reviews. Therefore, each of these seven EMF effects are established effects of Wi-Fi and of other microwave frequency EMFs. Each of these seven is also produced by downstream effects of the main action of such EMFs, voltage-gated calcium channel (VGCC) activation. While VGCC activation via EMF interaction with the VGCC voltage sensor seems to be the predominant mechanism of action of EMFs, other mechanisms appear to have minor roles. Minor roles include activation of other voltage-gated ion channels, calcium cyclotron resonance and the geomagnetic magnetoreception mechanism. Five properties of non-thermal EMF effects are discussed. These are that pulsed EMFs are, in most cases, more active than are non-pulsed EMFs; artificial EMFs are polarized and such polarized EMFs are much more active than non-polarized EMFs; dose-response curves are non-linear and non-monotone; EMF effects are often cumulative; and EMFs may impact young people more than adults. These general findings and data presented earlier on Wi-Fi effects were used to assess the Foster and Moulder (F&M) review of Wi-Fi. The F&M study claimed that there were seven important studies of Wi-Fi that each showed no effect. However, none of these were Wi-Fi studies, with each differing from genuine Wi-Fi in three distinct ways. F&M could, at most conclude that there was no statistically significant evidence of an effect. The tiny numbers studied in each of these seven F&M-linked studies show that each of them lack power to make any substantive conclusions. In conclusion, there are seven repeatedly found Wi-Fi effects which have also been shown to be caused by other

  14. A campus-wide Wi-Fi service for CERN

    CERN Document Server

    2016-01-01

    Improvements are coming to CERN’s Wi-Fi service as connectivity is improved in offices, restaurants and meeting rooms.   All Wi-Fi traffic will be routed via central controllers in CERN’s Computer Centre to provide a better managed service. (Image: Veronika McQuade/CERN) The IT department’s Communication Systems group has provided Wi-Fi connectivity at CERN for many years now but with a focus on meeting rooms, auditoriums and informal meeting places such as the restaurants. Although some buildings have Wi-Fi coverage in offices, most do not and CERN’s Wi-Fi service is lagging behind the demand driven by the growing number of tablets, lightweight laptops and other wireless-only devices. Furthermore, the current network infrastructure can’t cope with the many devices in the Main Auditorium during events such as the recent LIGO announcement and it often has difficulty handling the demand at Restaurant 1 during lunchtimes. The wireless access points d...

  15. Energy consumption model on WiMAX subscriber station

    Science.gov (United States)

    Mubarakah, N.; Suherman; Al-Hakim, M. Y.; Warman, E.

    2018-02-01

    Mobile communication technologies move toward miniaturization. Mobile device’s energy source relies on its battery endurance. The smaller the mobile device, it is expected the slower the battery drains. Energy consumption reduction in mobile devices has been of interest of researcher. In order to optimize energy consumption, its usage should be predictable. This paper proposes a model of predicted energy amount consumed by the WiMAX subscriber station by using regression analysis of active WiMAX states and their durations. The proposed model was assessed by using NS-2 simulation for more than a hundred thousand of recorded energy consumptions data in every WiMAX states. The assessment show a small average deviation between predicted and measured energy consumptions, about 0.18% for training data and 0.187% and 0.191% for test data.

  16. DNA synthesis in permeabilized WI38 and MRC5 cells

    International Nuclear Information System (INIS)

    Griffiths, T.D.; Carpenter, J.G.

    1980-01-01

    DNA synthesis was examined in cultures of growing WI38 and MRC5 cells made permeable to deoxyribonucleotides. Cells from late passage cultures showed a reduced rate of deoxythymidine triphosphate (dTTP) uptake as compared to cells from early- to mid-passage cultures. This reduction became evident earlier in WI38 cultures (passage 33) than in MRC5 cultures (passage 41). Although this reduced rate of incorporation appeared to be primarily due to a reduced percentage of replicating (S phase) cells in later passage cultures, some effect on the rate of DNA synthesis in replicating cells was also evident

  17. Maritime super Wi-Fi coverage based on TVWS

    Science.gov (United States)

    Ren, Jia; Chen, Baodan; Zhang, Yonghui; Huang, Fang

    2014-10-01

    After analyzing the occupancy and characteristics of television white space (TVWS), this paper proposes wireless broadband networking by using super Wi-Fi technology in maritime environment operating on TVWS. A sea surface channel model is developed for predicting maritime network coverage of super Wi-Fi technology. This channel model is based on Irregular Terrain Methodology (ITM) model with revised parameters and dual-path propagation effect. The simulations demonstrated that the sea surface channel model can accurately reflect the transmission loss of radio wave in TVWS.

  18. ANDROID CHATTING APPLICATION BASED ON WI-FI TECHNOLOGY

    OpenAIRE

    Ekata M. Lambture *, Prof. Z.M. Shaikh

    2016-01-01

    As we know that Android operating system is one of the popular operating system for mobile applications.It supports mobile applications such as Chatting based applications,File sharing applications etc. In market thosands of applications are available in which users can send-receive messages,shares the files,send images,audio,video through network connectivity such as 2G,3G,4G. Android chatting application based on wi-fi technology provides same features but using WI-FI(Wireless Fidelity)...

  19. Eesti Statoil seljatas emaettevõtte WiFiga / Annika Matson

    Index Scriptorium Estoniae

    Matson, Annika, 1976-

    2003-01-01

    Eesti teenindusjaamades pakutakse alates suvest tasuta traadita internetiühendust WiFi, Skandinaavimaades on WiFi alles paigutamisel. Lõpuks kasumis: tabelid ja diagrammid. Vt. samas: Statoili arengut pärsib maardlate ammendumine

  20. Primary Productivity, SeaWiFS and Pathfinder, 0.1 degrees, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from SeaWiFS Chl a, Pathfinder SST, and SeaWiFS PAR data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

  1. 75 FR 44044 - Environmental Impact Statements: National Summary of Rescinded Notices of Intent

    Science.gov (United States)

    2010-07-27

    ... Road in Rock County, Wisconsin to the interchange of Rockton Road and I-90 in Winnebago, Illinois... interchange of Rockton Road and I-90 in IL--Rock County, WI to Winnebago County, IL. MD University of Maryland..., Clear Creek, and Jefferson Counties, Colorado; County Road 951 project in Lee and Collier Counties...

  2. Estimating travel times using Wi-Fi sensor data

    NARCIS (Netherlands)

    Hoogendoorn, S.P.; Daamen, W.; Duives, D.C.; Yuan, Y.

    2016-01-01

    Determining travel time information from Wi-Fi (or Bluetooth) sensors is not trivial due to various (often technical) reasons. In this contribution, we focus on the problem of distinguishing travel time from the time people spend performing activities (e.g. fuelling the car, standing still to watch

  3. Wi-Fi Network Communication Technology Design | Onibere ...

    African Journals Online (AJOL)

    Transmission media (like Satellite, VSAT), access method used to transmit both voice and data on the networks and underlying software and hardware requirements. Also the various standards and protocol for proper wireless networks management, the various authentication and encryption techniques of Wi -Fi network ...

  4. 76 FR 49697 - Television Broadcasting Services; Eau Claire, WI

    Science.gov (United States)

    2011-08-11

    ...] Television Broadcasting Services; Eau Claire, WI AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: The Commission has before it a petition for rulemaking filed by Gray Television Licensee... the Congressional review Act, see 5 U.S.C. 801(a)(1)(A). List of Subjects in 47 CFR Part 73 Television...

  5. 76 FR 68124 - Television Broadcasting Services; Fond du Lac, WI

    Science.gov (United States)

    2011-11-03

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [MB Docket No. 09-115, RM-11543; DA 11-1502] Television Broadcasting Services; Fond du Lac, WI AGENCY: Federal Communications Commission. ACTION: Proposed rule. SUMMARY: In this document, the Commission denies a petition for reconsideration of an August 12...

  6. 76 FR 5300 - Proposed Amendment of Class E Airspace; Cable Union, WI

    Science.gov (United States)

    2011-01-31

    ... Federal Aviation Administration 14 CFR Part 71 Proposed Amendment of Class E Airspace; Cable Union, WI...: This action proposes to amend Class E airspace at Cable Union, WI. Decommissioning of the Seely non-directional beacon (NDB) at Cable Union Airport, Cable Union, WI, has made this action necessary for the...

  7. 76 FR 22014 - Amendment of Class E Airspace; Cable Union, WI

    Science.gov (United States)

    2011-04-20

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class E Airspace; Cable Union, WI AGENCY... airspace for Cable Union, WI. Decommissioning of the Seely non-directional beacon (NDB) at Cable Union Airport, Cable Union, WI, has made this action necessary to enhance the safety and management of...

  8. The role of regulation in preventing Wi-Fi over-congestion in densely populated areas

    NARCIS (Netherlands)

    Hartog, F.T.H. den; Nijs, J.M.M. de

    2017-01-01

    Given the ever increasing number of Wi-Fi devices in use by the public, the progressing urbanisation, and the current attempts by the industry to improve Wi-Fi system performance, we here analyse the case of apartment blocks with residents increasingly suffering from Wi-Fi over-congestion. Here,

  9. WiFi-Aided Magnetic Matching for Indoor Navigation with Consumer Portable Devices

    Directory of Open Access Journals (Sweden)

    You Li

    2015-06-01

    Full Text Available This paper presents a WiFi-aided magnetic matching (MM algorithm for indoor pedestrian navigation with consumer portable devices. This algorithm reduces both the mismatching rate (i.e., the rate of matching to an incorrect point that is more than 20 m away from the true value and computational load of MM by using WiFi positioning solutions to limit the MM search space. Walking tests with Samsung Galaxy S3 and S4 smartphones in two different indoor environments (i.e., Environment #1 with abundant WiFi APs and significant magnetic features, and Environment #2 with less WiFi and magnetic information were conducted to evaluate the proposed algorithm. It was found that WiFi fingerprinting accuracy is related to the signal distributions. MM provided results with small fluctuations but had a significant mismatch rate; when aided by WiFi, MM’s robustness was significantly improved. The outcome of this research indicates that WiFi and MM have complementary characteristics as the former is a point-by-point matching approach and the latter is based on profile-matching. Furthermore, performance improvement through integrating WiFi and MM depends on the environment (e.g., the signal distributions of magnetic intensity and WiFi RSS: In Environment #1 tests, WiFi-aided MM and WiFi provided similar results; in Environment #2 tests, the former was approximately 41.6% better. Our results supported that the WiFi-aided MM algorithm provided more reliable solutions than both WiFi and MM in the areas that have poor WiFi signal distribution or indistinctive magnetic-gradient features.

  10. Nadzor in upravljanje omrežij Wi-Fi

    OpenAIRE

    PEKEVSKI, BOJAN

    2016-01-01

    Iz današnje perspektive Wi-Fi dostop je zelo pomemben za vsakogar. Uporaba interneta je ogromna in velik del uporabnikov dostopa preko 802.11 WLAN (Wi-Fi) omrežjih. Taka omrežja so preprosta za namestitev in so primerna tako za domače uporabnike, kot tudi za velika podjetja. Možnost uvedbe stabilnih omrežjih v krajih, kjer je žična rešitev težja za izvajanje ali pa ni tako stroškovno učinkovita, je samo eden izmed razlogov za široko uporabo WLAN-a. Današnja WLAN omrežja postajajo vse bolj ...

  11. Evaluating the Performance of IPTV over Fixed WiMAX

    Science.gov (United States)

    Hamodi, Jamil; Salah, Khaled; Thool, Ravindra

    2013-12-01

    IEEE specifies different modulation techniques for WiMAX; namely, BPSK, QPSK, 16 QAM and 64 QAM. This paper studies the performance of Internet Protocol Television (IPTV) over Fixed WiMAX system considering different combinations of digital modulation. The performance is studied taking into account a number of key system parameters which include the variation in the video coding, path-loss, scheduling service classes different rated codes in FEC channel coding. The performance study was conducted using OPNET simulation. The performance is studied in terms of packet lost, packet jitter delay, end-to-end delay, and network throughput. Simulation results show that higher order modulation and coding schemes (namely, 16 QAM and 64 QAM) yield better performance than that of QPSK.

  12. Sending Safety Video over WiMAX in Vehicle Communications

    Directory of Open Access Journals (Sweden)

    Jun Steed Huang

    2013-10-01

    Full Text Available This paper reports on the design of an OPNET simulation platform to test the performance of sending real-time safety video over VANET (Vehicular Adhoc NETwork using the WiMAX technology. To provide a more realistic environment for streaming real-time video, a video model was created based on the study of video traffic traces captured from a realistic vehicular camera, and different design considerations were taken into account. A practical controller over real-time streaming protocol is implemented to control data traffic congestion for future road safety development. Our driving video model was then integrated with the WiMAX OPNET model along with a mobility model based on real road maps. Using this simulation platform, different mobility cases have been studied and the performance evaluated in terms of end-to-end delay, jitter and visual experience.

  13. Krakówi graafikasügis / Anne Untera

    Index Scriptorium Estoniae

    Untera, Anne, 1951-

    2009-01-01

    16. septembril avatud Krakówi rahvusvahelisest graafikatriennaalist. Grand prix läks poola graafikule Joanna Piechile. Läti graafik Guntars Sietiņš pälvis Varssavi kunstiakadeemia rektori auhinna. Eestit esindavad peanäitusel Ülle Marks, Benjamin Vasserman ja Eve Kask, satelliitnäitusel "PrintArt" Katowices Tiiu Prisko ja Mati Veermets ning kutsutud osalejatega satelliitnäitusel Torunis Evi Tihemets

  14. A WiFi public address system for disaster management.

    Science.gov (United States)

    Andrade, Nicholas; Palmer, Douglas A; Lenert, Leslie A

    2006-01-01

    The WiFi Bullhorn is designed to assist emergency workers in the event of a disaster situation by offering a rapidly configurable wireless of public address system for disaster sites. The current configuration plays either pre recorded or custom recorded messages and utilizes 802.11b networks for communication. Units can be position anywhere wireless coverage exists to help manage crowds or to recall first responders from dangerous areas.

  15. Wi-Fi Tags for the Remote and Virtual Laboratory

    Directory of Open Access Journals (Sweden)

    D. Ursutiu

    2008-04-01

    Full Text Available With the advancement of computer technologiesto faster processors and more memory, the WorldWideWeb,wireless communication, and miniaturization of sensortechnology, it is now possible to simulate and executeengineering and science laboratory projects on a remotecomputer. With Internet connection, students have access to"virtual laboratories" via the www, experiment-orientedproblems can be now offered without the overhead incurredwhen maintaining a full laboratory. This paper investigatesthe opportunity that a new wireless sensor technologybrings to remote laboratories.G2 Microsystems of Campbell, California, USA, released in2007 the first ever ultra-low power Wi-Fi System on a Chip(SoC named G2C501. This SoC includes a 32-bit CPU,crypto accelerator, real-time clock and a versatile sensorinterface that can serve as a standalone host subsystem. TheG2C501 goes beyond today’s basic radio frequencyidentification (RFID technology to offer intelligent trackingand sensor capabilities that leverage IEEE 802.11 (Wi-Finetworks. Due to its support for multiple locationtechnologies, small form factor and ultra-low powerconsumption, the G2C502 SoC can be integrated into Wi-Fisensor tags that lower cost of ownership and meet the needsof a variety of industries including consumer electronics,pharmaceuticals, chemical manufacturing, cold chain andmore.A battery powered, small size ultra low-power Wi-Fiwireless measurement node name IP Sensor has been builtusing the G2C501 SoC. Sensors for measurement oftemperature, humidity, light, and vibration or motion arecurrently mounted on the IP Sensor board. The node is ableto read a sensor and send data to the network by using anIP-based application protocol such as UDP.This paper describes the new IP Sensor

  16. Analisis Throughput Varian TCP Pada Model Jaringan WiMAX

    Directory of Open Access Journals (Sweden)

    Medi Taruk

    2016-07-01

    Full Text Available Transmission Control Protocol (TCP is a protocol that works at the transport layer of the OSI model. TCP was originally designed more destined for a wired network. However, to meet the need for the development of a very fast network technology based on the needs of the use by the user, it needs further development to the use of TCP on wireless devices. One implementation of a wireless network based on Worldwide Interoperability for Microwave Access (WiMAX network is a model that offers a variety advantage, particularly in terms of access speed. In this case, use NS-2 to see throughput at TCP variants tested, namely TCP-Tahoe, TCP-Reno, TCP-Vegas, and TCP-SACK over WiMAX network model, with few observations scenarios. The first is a look at each of these variants throughput of TCP when only one particular variant of the work in the network. Second observe all variants of TCP throughput at the same time and have the equivalent QoS, but with the possibility of a small congestion based on the capacity of the link is made sufficient. Third observed throughput with multi congestion. In WiMAX network has scheduling services are UGS, rtPS and ertPS using UDP protocol and nrtPS and BE using the TCP Protocol. By using the software network simulator (NS-2 to obtain performance comparison TCP protocol-based services on the WiMAX network with QoS parameters are throughput, packet loss, fairness and time delay.

  17. The genesis of WiFi and its applications

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    In 1985 changes to US regulations caused a paradigm shift by permitting the use of radio spectrum for devices that did not need to have an end-user license. After a few years, products appeared on the market and a group developed a standard for broadband wireless communications among computers. The presentation will explain how the standard developed and was adopted by the Wi-Fi Alliance, as well as the global harmonization and expansion of the available radio spectrum to over half a GHz. The success of Wi-Fi and user innovation and initiatives makes it a vehicle to bring broadband internet to rural areas both in developing as well as in developed countries. Vic Hayes is a Senior Research Fellow at the Delft University of Technology and is writing a book titled "The genesis of Wi-Fi and the road toward global success". He holds a BSEE and joined NCR in the Netherlands in 1974. He co-established and chaired the IEEE 802.11 Standards Working Group for Wireless Local Area Networks and became known as the "Fathe...

  18. HDACs and the senescent phenotype of WI-38 cells

    Directory of Open Access Journals (Sweden)

    Noonan Emily J

    2005-10-01

    Full Text Available Abstract Background Normal cells possess a limited proliferative life span after which they enter a state of irreversible growth arrest. This process, known as replicative senescence, is accompanied by changes in gene expression that give rise to a variety of senescence-associated phenotypes. It has been suggested that these gene expression changes result in part from alterations in the histone acetylation machinery. Here we examine the influence of HDAC inhibitors on the expression of senescent markers in pre- and post-senescent WI-38 cells. Results Pre- and post-senescent WI-38 cells were treated with the HDAC inhibitors butyrate or trichostatin A (TSA. Following HDAC inhibitor treatment, pre-senescent cells increased p21WAF1 and β-galactosidase expression, assumed a flattened senescence-associated morphology, and maintained a lower level of proteasome activity. These alterations also occurred during normal replicative senescence of WI-38 cells, but were not accentuated further by HDAC inhibitors. We also found that HDAC1 levels decline during normal replicative senescence. Conclusion Our findings indicate that HDACs impact numerous phenotypic changes associated with cellular senescence. Reduced HDAC1 expression levels in senescent cells may be an important event in mediating the transition to a senescent phenotype.

  19. Indoor positioning using differential Wi-Fi lateration

    Science.gov (United States)

    Retscher, Guenther; Tatschl, Thomas

    2017-12-01

    For Wi-Fi positioning usually location fingerprinting or (tri)lateration are employed whereby the received signal strengths (RSSs) of the surrounding Wi-Fi Access Points (APs) are scanned on the mobile devices and used to perform localization. Within the scope of this study, the position of a mobile user is determined on the basis of lateration. Two new differential approaches are developed and compared to two common models, i.e., the one-slope and multi-wall model, for the conversion of the measured RSS of the Wi-Fi signals into ranges. The two novel methods are termed DWi-Fi as they are derived either from the well-known DGPS or VLBI positioning principles. They make use of a network of reference stations deployed in the area of interest. From continuous RSS observations on these reference stations correction parameters are derived and applied by the user in real-time. This approach leads to a reduced influence of temporal and spatial variations and various propagation effects on the positioning result. In practical use cases conducted in a multi-storey office building with three different smartphones, it is proven that the two DWi-Fi approaches outperform the common models as static positioning yielded to position errors of about 5 m in average under good spatial conditions.

  20. Streaming Multimedia via Overlay Networks using Wi-Fi Peer-to-Peer Connections

    DEFF Research Database (Denmark)

    Poderys, Justas; Soler, José

    2017-01-01

    Short range ad-hoc wireless networks can be used to deliver streaming multimedia for information, entertainment and advertisement purposes. To enable short-range communication between various devices, the Wi-Fi Alliance proposed an extension to the IEEE802.11 Wi-Fi standard called Wi-Fi Peer......-to-Peer (P2P). It allows compliant devices to form ad-hoc communication groups without interrupting conventional access point-based Wi-Fi communication. This paper proposes to use Wi-Fi P2P connectivity to distribute streaming multimedia in ah-hoc formed user groups. The exchange of multimedia data...... is performed by forming an overlay network using Peer-to-Peer Streaming Peer Protocol (PPSPP). In order to make PPSPP function over WiFi P2P connections, this paper proposes a number of changes to the protocol. The performance of the proposed system is evaluated using a computer networks emulator...

  1. WiMAX security and quality of service an end-to-end perspective

    CERN Document Server

    Tang, Seok-Yee; Sharif, Hamid

    2010-01-01

    WiMAX is the first standard technology to deliver true broadband mobility at speeds that enable powerful multimedia applications such as Voice over Internet Protocol (VoIP), online gaming, mobile TV, and personalized infotainment. WiMAX Security and Quality of Service, focuses on the interdisciplinary subject of advanced Security and Quality of Service (QoS) in WiMAX wireless telecommunication systems including its models, standards, implementations, and applications. Split into 4 parts, Part A of the book is an end-to-end overview of the WiMAX architecture, protocol, and system requirements.

  2. On the Issues and Challenges of Fiber-Wireless (Fi-Wi Networks

    Directory of Open Access Journals (Sweden)

    Harry Tin Win

    2013-01-01

    Full Text Available The objective of this article is to present various aspects of Fiber-Wireless (Fi-Wi networks, which is a technology of current interest of the researchers. Fiber-wireless technology, known in short as “Fi-Wi,” is a combination of optical-fiber-based network and wireless network. Fi-Wi has recently come forward as one of the emerging future network technologies yet the term is often mixed up with wireless-fidelity (Wi-Fi technology. In fact, Wi-Fi network could be included in a Fi-Wi architecture. Due to the unfamiliarity with the term, “Fi-Wi” and similar sounding commonly known “Wi-Fi,” many students, even academics and practitioners sometimes may not be able to differentiate between these. In the recent years, a good number of works on various issues of Fi-Wi have come out, but an overall survey with the latest advancements in the area is yet to be found. Hence, in this work, we analyze various issues and challenges of implementing Fi-Wi networks in practical scenarios to allow researchers to find future directions of research and general readers to understand the issues better.

  3. Radiofrequency exposure from wireless LANs utilizing Wi-Fi technology.

    Science.gov (United States)

    Foster, Kenneth R

    2007-03-01

    This survey measured radiofrequency (RF) fields from wireless local area networks (WLANs) using Wi-Fi technology against a background of RF fields in the environment over the frequency range 75 MHz-3 GHz. A total of 356 measurements were conducted at 55 sites (including private residences, commercial spaces, health care and educational institutions, and other public spaces) in four countries (U.S., France, Germany, Sweden). Measurements were conducted under conditions that would result in the higher end of exposures from such systems. Where possible, measurements were conducted in public spaces as close as practical to the Wi-Fi access points. Additional measurements were conducted at a distance of approximately 1 m from a laptop while it was uploading and downloading large files to the WLAN. This distance was chosen to allow a useful comparison of fields in the far-field of the antenna in the laptop, and give a representative measure of the exposure that a bystander might receive from the laptop. The exposure to the user, particularly if the antenna of the client card were placed against his or her body, would require different measurement techniques beyond the scope of this study. In all cases, the measured Wi-Fi signal levels were very far below international exposure limits (IEEE C95.1-2005 and ICNIRP) and in nearly all cases far below other RF signals in the same environments. An discusses technical aspects of the IEEE 802.11 standard on which WLANs operate that are relevant to determining the levels of RF energy exposure from WLANs. Important limiting factors are the low operating power of client cards and access points, and the low duty cycle of transmission that normally characterizes their operation.

  4. WI-CERFP Respiratory Protection Optimization: A Detailed Analysis

    Science.gov (United States)

    2015-12-01

    AU/ACSC/2015 AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY WI-CERFP RESPIRATORY PROTECTION OPTIMIZATION: A DETAILED ANALYSIS By...vii INTRODUCTION………………………………………………………………………….. 1 RESPIRATORY PROTECTION...3 Theory of Respiratory Protection…………………………………………………… 3 Air Purifying Respiratory – Detailed Configuration……………………………....... 3 Powered Air

  5. STABILIZACIJA KVADROKOPTERJA IN DALJINSKI WI-FI VIDEO NADZOR TERENA

    OpenAIRE

    Zlatarek, Miha

    2015-01-01

    V diplomskem delu smo se ukvarjali s težavnostjo izdelave kvadrokopterja in nastavitve PID parametrov za stabilizacijo letenja kvadrokopterja. Poglobiti smo se morali v samo mehansko redukcijo tresljajev, saj prenašamo video signale s pomočjo mikroračunalnika Raspberry Pi ter PiCam preko Wi-Fi omrežja. Preverili smo možnosti daljinskega video nadzora kvadrokopterja preko Raspberry Pi platforme. Opisana je celotna sestava kvadrokopterja, z opisom pripadajočih delov, ter celoten postopek na...

  6. RRM Strategies in LTE&WiMAX Interworking System

    DEFF Research Database (Denmark)

    Zakrzewska, Anna; Ruepp, Sarah Renée; Berger, Michael Stübert

    high quality streaming video. In order to provide those demanding real-time multimedia and very high data rates, scarce radio resources must be used effectively to maximize the channel utilization. The presentation will focus on scheduling techniques possibly adaptable to dynamically changing network......, that could be applied in 4G systems (LTE interworking with WiMAX is considered). Furthermore, it will also discuss the Radio Resource Management (RRM) problem addressing the challenges of designing a RRM system for such a multi-RAT wireless environment. Different functionalities and possibilities...

  7. Accesso Wi-Fi federato dell'Area della Ricerca di Pisa WiFi@PiCNR

    OpenAIRE

    Gebrehiwot, Abraham; De Vita, Andrea

    2011-01-01

    The CNR Research Area of Pisa has a Wi-FI coverage in the campus. The wireless network is designed and implemented by the Institute of Informatics and Telematics of CNR which is in charge of managing the network infrastructure and also providing a number of other services to researchers in the campus. The wireless network is a centralized solution based on Cisco Wireless LAN Controller (WLC). In the campus area various wireless networks are defined, including the SSID "guest" with a Captive P...

  8. Inferring Stop-Locations from WiFi.

    Directory of Open Access Journals (Sweden)

    David Kofoed Wind

    Full Text Available Human mobility patterns are inherently complex. In terms of understanding these patterns, the process of converting raw data into series of stop-locations and transitions is an important first step which greatly reduces the volume of data, thus simplifying the subsequent analyses. Previous research into the mobility of individuals has focused on inferring 'stop locations' (places of stationarity from GPS or CDR data, or on detection of state (static/active. In this paper we bridge the gap between the two approaches: we introduce methods for detecting both mobility state and stop-locations. In addition, our methods are based exclusively on WiFi data. We study two months of WiFi data collected every two minutes by a smartphone, and infer stop-locations in the form of labelled time-intervals. For this purpose, we investigate two algorithms, both of which scale to large datasets: a greedy approach to select the most important routers and one which uses a density-based clustering algorithm to detect router fingerprints. We validate our results using participants' GPS data as well as ground truth data collected during a two month period.

  9. Effective Bandwidth Allocation for WiMAX Mesh Network

    Directory of Open Access Journals (Sweden)

    Hung-Chin Jang

    2010-04-01

    Full Text Available The aim of this paper is to reduce the media access delay in a WiMAX mesh network. We observe that as the number of subscriber stations (SS in a neighborhood increases, the processes of transmission opportunity (TO competition and 3- way handshake are easy to fail. This may degrade transmission efficiency and increase packet transmission delay. Besides, the minislot allocation defined in the WiMAX mesh mode may cause many lower priority services reserve earlier minislots than that of higher priority services like rtPS. This may cause great negative impact on delay-sensitive traffic. In this paper, we design a QoS classifier to enqueue packets according to different QoS service classes, present a dynamic holdoff exponent mechanism to reduce control subframe delay, and propose a Neighborhood-Based Minislot Allocation (NBMA mechanism to reduce data subframe delay. Simulations show that the proposed methodology outperforms that of IEEE 802.16 and Baye's DynExp in delay, jitter and throughput.

  10. Automatic Construction of Wi-Fi Radio Map Using Smartphones

    Science.gov (United States)

    Liu, Tao; Li, Qingquan; Zhang, Xing

    2016-06-01

    Indoor positioning could provide interesting services and applications. As one of the most popular indoor positioning methods, location fingerprinting determines the location of mobile users by matching the received signal strength (RSS) which is location dependent. However, fingerprinting-based indoor positioning requires calibration and updating of the fingerprints which is labor-intensive and time-consuming. In this paper, we propose a visual-based approach for the construction of radio map for anonymous indoor environments without any prior knowledge. This approach collects multi-sensors data, e.g. video, accelerometer, gyroscope, Wi-Fi signals, etc., when people (with smartphones) walks freely in indoor environments. Then, it uses the multi-sensor data to restore the trajectories of people based on an integrated structure from motion (SFM) and image matching method, and finally estimates location of sampling points on the trajectories and construct Wi-Fi radio map. Experiment results show that the average location error of the fingerprints is about 0.53 m.

  11. Effects of Implementing Adaptable Channelization in Wi-Fi Networks

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2016-01-01

    Full Text Available The unprecedented increase of wireless devices is now facing a serious threat of spectrum scarcity. The situation becomes even worse due to inefficient frequency distribution protocols, deployed in trivial Wi-Fi networks. The primary source of this inefficiency is static channelization used in wireless networks. In this work, we investigate the use of dynamic and flexible channelization, for optimal spectrum utilization in Wi-Fi networks. We propose optimal spectrum sharing algorithm (OSSA and analyze its effect on exhaustive list of essential network performance measuring parameters. The elementary concept of the proposed algorithm lies in the fact that frequency spectrum should be assigned to any access point (AP based on its current requirement. The OSSA algorithm assigns channels with high granularity, thus maximizing spectrum utilization by more than 20% as compared to static width channel allocation. This optimum spectrum utilization, in turn, increases throughput by almost 30% in many deployment scenarios. The achieved results depict considerable decrease in interference, while simultaneously increasing range. Similarly signal strength values at relatively longer distances improve significantly at narrower channel widths while simultaneously decreasing bit error rates. We found that almost 25% reduction in interference is possible in certain scenarios through proposed algorithm.

  12. Inferring Stop-Locations from WiFi.

    Science.gov (United States)

    Wind, David Kofoed; Sapiezynski, Piotr; Furman, Magdalena Anna; Lehmann, Sune

    2016-01-01

    Human mobility patterns are inherently complex. In terms of understanding these patterns, the process of converting raw data into series of stop-locations and transitions is an important first step which greatly reduces the volume of data, thus simplifying the subsequent analyses. Previous research into the mobility of individuals has focused on inferring 'stop locations' (places of stationarity) from GPS or CDR data, or on detection of state (static/active). In this paper we bridge the gap between the two approaches: we introduce methods for detecting both mobility state and stop-locations. In addition, our methods are based exclusively on WiFi data. We study two months of WiFi data collected every two minutes by a smartphone, and infer stop-locations in the form of labelled time-intervals. For this purpose, we investigate two algorithms, both of which scale to large datasets: a greedy approach to select the most important routers and one which uses a density-based clustering algorithm to detect router fingerprints. We validate our results using participants' GPS data as well as ground truth data collected during a two month period.

  13. AUTOMATIC CONSTRUCTION OF WI-FI RADIO MAP USING SMARTPHONES

    Directory of Open Access Journals (Sweden)

    T. Liu

    2016-06-01

    Full Text Available Indoor positioning could provide interesting services and applications. As one of the most popular indoor positioning methods, location fingerprinting determines the location of mobile users by matching the received signal strength (RSS which is location dependent. However, fingerprinting-based indoor positioning requires calibration and updating of the fingerprints which is labor-intensive and time-consuming. In this paper, we propose a visual-based approach for the construction of radio map for anonymous indoor environments without any prior knowledge. This approach collects multi-sensors data, e.g. video, accelerometer, gyroscope, Wi-Fi signals, etc., when people (with smartphones walks freely in indoor environments. Then, it uses the multi-sensor data to restore the trajectories of people based on an integrated structure from motion (SFM and image matching method, and finally estimates location of sampling points on the trajectories and construct Wi-Fi radio map. Experiment results show that the average location error of the fingerprints is about 0.53 m.

  14. Complete Genome Sequence of Lactobacillus curvatus Strain WiKim38 Isolated from Kimchi

    Science.gov (United States)

    Lee, Se Hee; Jung, Min Young; Song, Jung-Hee; Lee, Moeun

    2017-01-01

    ABSTRACT Lactobacillus curvatus WiKim38 is a potential probiotic strain isolated from kimchi, a traditional Korean fermented food. The complete genome of the WiKim38 strain consisted of a circular chromosome of 1,940,170 bp in length with a G+C content of 41.93%. PMID:28473381

  15. FeltRadio – Experiencing Community-generated WiFi Activities

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Gronvall, Erik

    2016-01-01

    FeltRadio is a portable technology for sensing WiFi through sensorial augmentation and Electric Muscle Stimulation (EMS). The technology enables its wearer to sensorially engage with the radio waves and WiFi activities that have become an integrated part of our everyday lives. The sensorial...

  16. The making of the Women in Biology forum (WiB) at Bioclues.

    Science.gov (United States)

    Singhania, Reeta Rani; Madduru, Dhatri; Pappu, Pranathi; Panchangam, Sameera; Suravajhala, Renuka; Chandrasekharan, Mohanalatha

    2014-01-01

    The Women in Biology forum (WiB) of Bioclues (India) began in 2009 to promote and support women pursuing careers in bioinformatics and computational biology. WiB was formed in order to help women scientists deprived of basic research, boost the prominence of women scientists particularly from developing countries, and bridge the gender gap to innovation. WiB has also served as a platform to highlight the work of established female scientists in these fields. Several award-winning women researchers have shared their experiences and provided valuable suggestions to WiB. Headed by Mohanalatha Chandrasekharan and supported by Dr. Reeta Rani Singhania and Renuka Suravajhala, WiB has seen major progress in the last couple of years particularly in the two avenues Mentoring and Research, off the four avenues in Bioclues: Mentoring, Outreach, Research and Entrepreneurship (MORE). In line with the Bioclues vision for bioinformatics in India, the WiB Journal Club (JoC) recognizes women scientists working on functional genomics and bioinformatics, and provides scientific mentorship and support for project design and hypothesis formulation. As a part of Bioclues, WiB members practice the group's open-desk policy and its belief that all members are free to express their own thoughts and opinions. The WiB forum appreciates suggestions and welcomes scientists from around the world to be a part of their mission to encourage women to pursue computational biology and bioinformatics.

  17. The making of the Women in Biology forum (WiB at Bioclues.

    Directory of Open Access Journals (Sweden)

    Reeta Rani Singhania

    2014-01-01

    Full Text Available The Women in Biology forum (WiB of Bioclues (India began in 2009 to promote and support women pursuing careers in bioinformatics and computational biology. WiB was formed in order to help women scientists deprived of basic research, boost the prominence of women scientists particularly from developing countries, and bridge the gender gap to innovation. WiB has also served as a platform to highlight the work of established female scientists in these fields. Several award-winning women researchers have shared their experiences and provided valuable suggestions to WiB. Headed by Mohanalatha Chandrasekharan and supported by Dr. Reeta Rani Singhania and Renuka Suravajhala, WiB has seen major progress in the last couple of years particularly in the two avenues Mentoring and Research, off the four avenues in Bioclues: Mentoring, Outreach, Research and Entrepreneurship (MORE. In line with the Bioclues vision for bioinformatics in India, the WiB Journal Club (JoC recognizes women scientists working on functional genomics and bioinformatics, and provides scientific mentorship and support for project design and hypothesis formulation. As a part of Bioclues, WiB members practice the group's open-desk policy and its belief that all members are free to express their own thoughts and opinions. The WiB forum appreciates suggestions and welcomes scientists from around the world to be a part of their mission to encourage women to pursue computational biology and bioinformatics.

  18. Mārketinga koncepcijas izveide Wi-Fi pakalpojumam Latvijā

    OpenAIRE

    Zauers, Mārtiņš 

    2008-01-01

    Maģistra darbā Wi-Fi mārketinga koncepcijas izveide Latvijā autors apkopo teoriju par mārketingu un tā koncepcijas izveidi, analizē tehnisko literatūru par Wi-Fi, Wi-Fi vēsturi, izveidošanos Latvijā un apkopo datus par Wi-Fi tirgus attīstību Latvijā, kā arī Lattelecom Wi-Fi pakalpojumu. Pētījuma mērķis ir analizēt un vērtēt Lattelecom Wi-Fi pakalpojuma pieejamību Latvijā un izstrādāt tā mārketinga koncepciju. Analizējot Wi-Fi pakalpojuma tirgu Latvijā, pētījuma daļā autors izveido Wi-Fi p...

  19. Indoor path loss prediction for Wi-Fi network in ultrahigh frequency ...

    African Journals Online (AJOL)

    In this work, Wi-Fi received signal strength was monitored in an indoor environment at 2437 MHz in ultrahigh frequency band of channel 6. The received signal strength was compressed, decomposed, filtered and reconstructed using one dimensional multi – resolution technique in order to predict how Wi-Fi received signal ...

  20. Enhancing Teaching and Learning Wi-Fi Networking Using Limited Resources to Undergraduates

    Science.gov (United States)

    Sarkar, Nurul I.

    2013-01-01

    Motivating students to learn Wi-Fi (wireless fidelity) wireless networking to undergraduate students is often difficult because many students find the subject rather technical and abstract when presented in traditional lecture format. This paper focuses on the teaching and learning aspects of Wi-Fi networking using limited hardware resources. It…

  1. A pathway to solving the Wi-Fi Tragedy of the Commons in apartment blocks

    NARCIS (Netherlands)

    Hartog, F. Den; Kemper, P.L.; Boltjes, B.; Raschella, A.; Bouhafs,F.; Seyedebrahimi, M.

    2017-01-01

    Surprisingly little research has quantified the severity of Wi-Fi congestion in densely populated areas. We performed a high-fidelity 3D simulation of the performance of a realistic Wi-Fi deployment in a typical apartment block. Our results show that congestion leads to significant loss of

  2. Noteworthy lichen species in Poland collected in the Świętokrzyski National Park

    Directory of Open Access Journals (Sweden)

    Anna Łubek

    2014-08-01

    Full Text Available In this paper 25 species of the lichens new to the Świętokrzyski National Park are presented on the basis of recent collection and revision of the herbarial material from this arc. Some of these species are new to the Świętokrzykie Mountains and one have not been recorded in Poland so far.

  3. Passive WiFi monitoring of the rhythm of the campus

    NARCIS (Netherlands)

    Kalogianni, E.; Sileryte, R.; Lam, M.; Zhou, K.; Van der Ham, M.; Van der Spek, S.C.; Verbree, E.

    2015-01-01

    Within this research-driven project, passive WiFi monitoring of WiFi enabled devices was used to detect users (students, employees, visitors) of buildings at the campus of Delft University of Technology to gain insight into the Rhythm of the Campus: the occupation, duration of stay and moving

  4. LTE/Wi-Fi Coexistence in 5 GHz ISM Spectrum: Issues, Solutions and Perspectives

    DEFF Research Database (Denmark)

    Abinader, Fuad; A. de Sousa Jr., Vicente; Choudhurry, Sayantan

    2018-01-01

    on the unlicensed band. Wi-Fi technology is widespread and also operates in the 5 GHz ISM spectrum bands, which may bring performance issues due to the coexistence of both technologies in the same spectrum band. This work is dedicated to the study of coexistence between LTE and Wi-Fi access systems operating in 5...

  5. WiFi in Schools, Electromagnetic Fields and Cell Phones: Alberta Health Fact Sheet

    Science.gov (United States)

    Alberta Education, 2012

    2012-01-01

    Wireless devices and the networks that support them are becoming more common in Alberta schools. WiFi is a wireless networking technology that allows computers and other devices to communicate over a wireless signal. Typically the signal is carried by radio waves over an area of up to 100 meters. Through the implementation of a WiFi network,…

  6. 3G Femto or 802.11g WiFi

    DEFF Research Database (Denmark)

    Jørgensen, Niels T.K.; Rodriguez Larrad, Ignacio; Elling, Jan

    2014-01-01

    In this paper HSPA Release 6 femto and IEEE 802.11g WiFi indoor data solutions are investigated from an end user perspective. Femto and WiFi access points are deployed at typical locations in an urban environment and end user performance is measured. Three key performance indicators (KPI) were...

  7. 76 FR 28073 - Notice of Inventory Completion: Logan Museum of Anthropology, Beloit College, Beloit, WI

    Science.gov (United States)

    2011-05-13

    ... Museum of Anthropology, Beloit College, Beloit, WI AGENCY: National Park Service, Interior. ACTION... the Logan Museum of Anthropology, Beloit College, Beloit, WI. The human remains were removed from... assessment of the human remains was made by the Logan Museum of Anthropology, Beloit College, professional...

  8. 76 FR 28075 - Notice of Inventory Completion: Logan Museum of Anthropology, Beloit College, Beloit, WI

    Science.gov (United States)

    2011-05-13

    ... Museum of Anthropology, Beloit College, Beloit, WI AGENCY: National Park Service, Interior. ACTION... funerary objects in the possession of the Logan Museum of Anthropology, Beloit College, Beloit, WI. The... assessment of the human remains was made by the Logan Museum of Anthropology, Beloit College, professional...

  9. 78 FR 44596 - Notice of Inventory Completion: State Historical Society of Wisconsin, Madison, WI

    Science.gov (United States)

    2013-07-24

    ... address in this notice by August 23, 2013. ADDRESSES: Jennifer Kolb, Wisconsin Historical Museum, 30 North Carroll Street, Madison, WI 53703, telephone (608) 261-2461, email Jennifer.Kolb@wisconsinhistory.org... request to Jennifer Kolb, Wisconsin Historical Museum, 30 North Carroll Street, Madison, WI 53703...

  10. Wi-Learn: An Innovative Learning Paradigm for the University of ...

    African Journals Online (AJOL)

    ... Wi-Learn, enfolds a set of mobile collaborative applications, such as wireless ile transfer, multiuser whiteboard sharing, audio and video conferencing, voting poll, SMS breaking news and revision quiz, using different wireless communication technologies. Keywords: M-learning, pervasive, education, WiFi, Bluetooth ...

  11. Simulátor pro pasivní multistatický radar s použitím WiFi/WiMAX

    OpenAIRE

    Sládek, Ondřej

    2017-01-01

    Diplomová práce se zabývá konceptem pasivního multistatického radaru. Radiolokačním signálem zkoumaného radaru je signál WiFi nebo WiMAX, který je vysílán nespolupracujícím vysílačem. Diplomová práce vyhodnocuje omezení, vyplývající z použití WiFi nebo WiMAX signálů. V rámci práce byl sestaven simulátor v prostředí Matlab, který ověřil základní myšlenku tohoto konceptu. Na základě výsledků simulací s reálnými parametry jsou formulovány závěry směrem k možnému využití WiFi/WiMAX radaru. Thi...

  12. WiFi : Une nouvelle façon de combler le fossé numérique ? | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    13 juil. 2011 ... Wi-fi: a new bridge for the digital divide? Connecting to the Internet using a simple aluminum antenna and a wireless network card coul. View moreWi-fi: a new bridge for the digital divide?

  13. Effects of melatonin on Wi-Fi-induced oxidative stress in lens of rats.

    Science.gov (United States)

    Tök, Levent; Nazıroğlu, Mustafa; Doğan, Salih; Kahya, Mehmet Cemal; Tök, Ozlem

    2014-01-01

    Melatonin has been considered a potent antioxidant that detoxifies a variety of reactive oxygen species in many pathophysiological states of eye. The present study was designed to determine the effects of Wi-Fi exposure on the lens oxidant, antioxidant redox systems, as well as the possible protective effects of melatonin on the lens injury induced by electromagnetic radiation (EMR). Thirty-two rats were used in the current study and they were randomly divided into four equal groups as follows: First and second groups were cage-control and sham-control rats. Rats in third group were exposed to Wi-Fi (2.45 GHz) for duration of 60 min/day for 30 days. As in the third group, the fourth group was treated with melatonin. The one-hour exposure to irradiation in second, third and fourth took place at noon each day. Lipid peroxidation levels in the lens were slightly higher in third (Wi-Fi) group than in cage and sham control groups although their concentrations were significantly (P Wi-Fi group than in cage and sham control groups although GSH-Px (P Wi-Fi + melatonin group than in Wi-Fi group. There are poor oxidative toxic effects of one hour of Wi-Fi exposure on the lens in the animals. However, melatonin supplementation in the lens seems to have protective effects on the oxidant system by modulation of GSH-Px activity.

  14. Exposure to Radiofrequency Electromagnetic Fields From Wi-Fi in Australian Schools.

    Science.gov (United States)

    Karipidis, Ken; Henderson, Stuart; Wijayasinghe, Don; Tjong, Lydiawati; Tinker, Rick

    2017-08-01

    The increasing use of Wi-Fi in schools and other places has given rise to public concern that the radiofrequency (RF) electromagnetic fields from Wi-Fi have the potential to adversely affect children. The current study measured typical and peak RF levels from Wi-Fi and other sources in 23 schools in Australia. All of the RF measurements were much lower than the reference levels recommended by international guidelines for protection against established health effects. The typical and peak RF levels from Wi-Fi in locations occupied by children in the classroom were of the order of 10-4 and 10-2% of the exposure guidelines, respectively. Typical RF levels in the classroom were similar between Wi-Fi and radio but higher than other sources. In the schoolyard typical RF levels were higher for radio, TV and mobile phone base stations compared to Wi-Fi. The results of this study showed that the typical RF exposure of children from Wi-Fi at school is very low and comparable or lower to other sources in the environment. © The Author 2017. Published by Oxford University Press.

  15. Electromagnetic immunity of implantable pacemakers exposed to wi-fi devices.

    Science.gov (United States)

    Mattei, Eugenio; Censi, Federica; Triventi, Michele; Calcagnini, Giovanni

    2014-10-01

    The purpose of this study is to evaluate the potential for electromagnetic interference (EMI) and to assess the immunity level of implantable pacemakers (PM) when exposed to the radiofrequency (RF) field generated by Wi-Fi devices. Ten PM from five manufacturers, representative of what today is implanted in patients, have been tested in vitro and exposed to the signal generated by a Wi-Fi transmitter. An exposure setup that reproduces the actual IEEE 802.11b/g protocol has been designed and used during the tests. The system is able to amplify the Wi-Fi signal and transmits at power levels higher than those allowed by current international regulation. Such approach allows one to obtain, in case of no EMI, a safety margin for PM exposed to Wi-Fi signals, which otherwise cannot be derived if using commercial Wi-Fi equipment. The results of this study mitigate concerns about using Wi-Fi devices close to PM: none of the PM tested exhibit any degradation of their performance, even when exposed to RF field levels five times higher than those allowed by current international regulation (20 W EIRP). In conclusion, Wi-Fi devices do not pose risks of EMI to implantable PM. The immunity level of modern PM is much higher than the transmitting power of RF devices operating at 2.4 GHz.

  16. Dominant Channel Occupancy for Wi-Fi Backscatter Uplink in Industrial Internet of Things

    Directory of Open Access Journals (Sweden)

    Jung-Hyok Kwon

    2016-12-01

    Full Text Available This paper presents a dominant channel occupancy (DCO mechanism for the Wi-Fi backscatter uplink in the industrial Internet of things (IIoT. The DCO provides high-priority channel access and reliable burst transmission to the Wi-Fi backscatter devices, thereby enabling the Wi-Fi backscatter tag to deliver its tag information to the Wi-Fi reader without interference from neighboring legacy Wi-Fi devices to guarantee the timeliness and reliability of the IIoT system. For the former, we consider three types of medium access control (MAC configurations: “carrier sense multiple access with collision avoidance (CSMA/CA starting with short inter-frame space (SIFS”, “freezing of the backoff period”, and “reduced CWmin.” In addition, the DCO uses the SIFS between burst packets to guarantee reliable burst transmission. To verify the effectiveness of DCO and determine a proper value for MAC parameters, we conduct experimental simulations under IEEE 802.11n PHY/MAC environments. The simulation results show that the reduced CWmin has the most significant effect on the channel occupancy. The Wi-Fi backscatter devices achieve much higher throughput than the separate cases when two or more configurations are used simultaneously. Moreover, the results exhibit that the use of SIFS between consecutive packets supports reliable burst transmission regardless of the transmission of the legacy Wi-Fi devices in the vicinity.

  17. Exposure to radiofrequency electromagnetic fields from Wi-Fi in Australian schools

    International Nuclear Information System (INIS)

    Karipidis, Ken; Henderson, Stuart; Wijayasinghe, Don; Tjong, Lydiawati; Tinker, Rick

    2017-01-01

    The increasing use of Wi-Fi in schools and other places has given rise to public concern that the radiofrequency (RF) electromagnetic fields from Wi-Fi have the potential to adversely affect children. The current study measured typical and peak RF levels from Wi-Fi and other sources in 23 schools in Australia. All of the RF measurements were much lower than the reference levels recommended by international guidelines for protection against established health effects. The typical and peak RF levels from Wi-Fi in locations occupied by children in the classroom were of the order of 10 4 and 10 2 % of the exposure guidelines, respectively. Typical RF levels in the classroom were similar between Wi-Fi and radio but higher than other sources. In the school yard typical RF levels were higher for radio, TV and mobile phone base stations compared to Wi-Fi. The results of this study showed that the typical RF exposure of children from Wi-Fi at school is very low and comparable or lower to other sources in the environment. (authors)

  18. The making of the Women in Biology forum (WiB) at Bioclues.

    OpenAIRE

    Reeta Rani Singhania; Dhatri Madduru; Pranathi Pappu; Sameera Panchangam; Renuka Suravajhala; Mohanalatha Chandrasekharan

    2014-01-01

    The Women in Biology forum (WiB) of Bioclues (India) began in 2009 to promote and support women pursuing careers in bioinformatics and computational biology. WiB was formed in order to help women scientists deprived of basic research, boost the prominence of women scientists particularly from developing countries, and bridge the gender gap to innovation. WiB has also served as a platform to highlight the work of established female scientists in these fields. Several award-winning women resear...

  19. A comparative analysis of Indoor WiFi Positioning at a large building complex

    DEFF Research Database (Denmark)

    Mathisen, Andreas; Krogh, Søren; Stisen, Allan

    2016-01-01

    Indoor Positioning based on WiFi has received extensive focus from research communities, owing its promises of ubiquitous positioning indoors for a variety of applications. The majority of the existing research on WiFi positioning centers around the improvement of positioning accuracy. However...... are in daily use. The positioning methods covered utilizes received signal strength from existing WiFi infrastructure to ease deployment and maintenance. We identify meaningful key metrics which describe different aspects of the methods’ performance. Using these metrics, we furthermore report on experiences...

  20. LTE/Wi-Fi Coexistence in 5 GHz ISM Spectrum: Issues, Solutions and Perspectives

    DEFF Research Database (Denmark)

    Abinader, Fuad; A. de Sousa Jr., Vicente; Choudhurry, Sayantan

    2018-01-01

    solutions is the aggregation of ISM unlicensed spectrum to licensed bands, using wireless networks defined by IEEE and 3GPP. While Wi-Fi networks are aggregated to LTE small cells via LTE/WLAN Aggregation (LWA), in proposals like LTE-U and LAA-LTE, the LTE air interface itself is used for transmission...... on the unlicensed band. Wi-Fi technology is widespread and also operates in the 5 GHz ISM spectrum bands, which may bring performance issues due to the coexistence of both technologies in the same spectrum band. This work is dedicated to the study of coexistence between LTE and Wi-Fi access systems operating in 5...

  1. LTE, WiMAX and WLAN network design, optimization and performance analysis

    CERN Document Server

    Korowajczuk, Leonhard

    2011-01-01

    A technological overview of LTE and WiMAX LTE, WiMAX and WLAN Network Design, Optimization and Performance Analysis provides a practical guide to LTE and WiMAX technologies introducing various tools and concepts used within. In addition, topics such as traffic modelling of IP-centric networks, RF propagation, fading, mobility, and indoor coverage are explored; new techniques which increase throughput such as MIMO and AAS technology are highlighted; and simulation, network design and performance analysis are also examined. Finally, in the latter part of the book Korowajczuk gives a step-by-step

  2. SeaWiFS_L3m_CU_LAND_NDVI_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  3. SeaWiFS_L3m_MC_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  4. SeaWiFS_L3m_SNSP_CHL_chlor_a_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  5. SeaWiFS_L3m_SNSP_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  6. SeaWiFS_L3m_WC_POC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  7. SeaWiFS_L3b_SNSP_KD490

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  8. SeaWiFS_L3m_SCSU_RRS_angstrom_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  9. SeaWiFS_L3m_SCSU_KD490_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  10. SeaWiFS_L3m_SNSP_LAND_NDVI_4km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  11. Towards the validation of SeaWiFS in Southern African Waters: The ...

    African Journals Online (AJOL)

    emission matrices, performed on filtered seawater samples. Modelled bio-optical data, using conditions typical of high biomass marine environments, are then used to assess the performance of a proposed SeaWiFS combined algorithm with ...

  12. SeaWiFS_L3m_YR_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  13. SeaWiFS_L3m_SNAU_CHL_chlor_a_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  14. SeaWiFS_L3m_SCAU_LAND_NDVI_4km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  15. SeaWiFS_L3m_WC_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  16. SeaWiFS_L3b_8D_LAND

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  17. SeaWiFS_L3m_DAY_RRS_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  18. SeaWiFS_L3m_SNWI_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  19. SeaWiFS_L3m_SNAU_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  20. SeaWiFS_L3b_R32_KD490

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  1. SeaWiFS_L3m_MO_RRS_angstrom_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  2. SeaWiFS_L3b_R32_PIC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  3. SeaWiFS_L3m_MO_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  4. SeaWiFS_L3m_8D_RRS_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  5. SeaWiFS_L3m_R32_CHL_chlor_a_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  6. SeaWiFS_L3b_R32_PAR

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  7. SeaWiFS_L3m_8D_KD490_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  8. SeaWiFS_L3b_8D_PIC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  9. SeaWiFS_L3m_R32_RRS_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  10. SeaWiFS_L3m_CU_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  11. SeaWiFS_L3m_MC_PIC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  12. SeaWiFS_L3m_SCWI_LAND_NDVI_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  13. SeaWiFS_L3m_SNAU_RRS_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  14. SeaWiFS_L3m_SCSU_LAND_NDVI_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  15. SeaWiFS_L3b_8D_KD490

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  16. SeaWiFS_L3b_R32_RRS

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  17. SeaWiFS_L3m_MO_CHL_chlor_a_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  18. SeaWiFS_L3m_WC_CHL_chlor_a_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  19. SeaWiFS_L3m_WC_KD490_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  20. SeaWiFS_L3m_CU_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  1. SeaWiFS_L3m_SNSP_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  2. SeaWiFS_L3m_SNSU_POC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  3. SeaWiFS_L3m_SNSU_CHL_chlor_a_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  4. SeaWiFS_L3m_SNSP_PIC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  5. SeaWiFS_L3m_MC_KD490_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  6. SeaWiFS_L3m_8D_POC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  7. SeaWiFS_L3m_MO_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  8. SeaWiFS_L3m_R32_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  9. SeaWiFS_L3m_WC_PIC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  10. SeaWiFS_L3m_DAY_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  11. SeaWiFS_L3m_SCAU_LAND_NDVI_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  12. SeaWiFS_L3b_SNSU_KD490

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  13. SeaWiFS_L3b_MO_KD490

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  14. SeaWiFS_L3m_R32_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  15. Collaborative WiFi Fingerprinting Using Sensor-Based Navigation on Smartphones.

    Science.gov (United States)

    Zhang, Peng; Zhao, Qile; Li, You; Niu, Xiaoji; Zhuang, Yuan; Liu, Jingnan

    2015-07-20

    This paper presents a method that trains the WiFi fingerprint database using sensor-based navigation solutions. Since micro-electromechanical systems (MEMS) sensors provide only a short-term accuracy but suffer from the accuracy degradation with time, we restrict the time length of available indoor navigation trajectories, and conduct post-processing to improve the sensor-based navigation solution. Different middle-term navigation trajectories that move in and out of an indoor area are combined to make up the database. Furthermore, we evaluate the effect of WiFi database shifts on WiFi fingerprinting using the database generated by the proposed method. Results show that the fingerprinting errors will not increase linearly according to database (DB) errors in smartphone-based WiFi fingerprinting applications.

  16. SeaWiFS_L3b_MC_KD490

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  17. SeaWiFS_L3b_8D_POC

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  18. SeaWiFS_L3m_SNSU_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  19. SAFARI 2000 SeaWiFS Images for Core Study Sites, 2000-2001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Sea-viewing Wide Field-of-view Sensor (SeaWiFS) imagery for the eight core study sites of Mongu, Etosha, Kasangu, Skukuza, Mutoko, Mzola,...

  20. SAFARI 2000 SeaWiFS Images for Core Study Sites, 2000-2001

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains Sea-viewing Wide Field-of-view Sensor (SeaWiFS) imagery for the eight core study sites of Mongu, Etosha, Kasangu, Skukuza, Mutoko,...

  1. SeaWiFS_L3m_SNAU_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  2. SeaWiFS_L3m_MC_RRS_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  3. SeaWiFS_L3m_SNSP_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  4. SeaWiFS_L3m_YR_RRS_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  5. SeaWiFS_L3m_SCSP_POC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  6. SeaWiFS_L3m_DAY_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  7. EnviroAtlas - Green Bay, WI - Meter-Scale Urban Land Cover (MULC) Data (2010)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Green Bay, WI Meter-Scale Urban Land Cover (MULC) dataset comprises 936 km2 around the city of Green Bay, surrounding towns, tribal lands and rural areas in...

  8. SeaWiFS_L3m_YR_CDOM_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  9. SeaWiFS_L3m_R32_LAND_NDVI_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  10. EnviroAtlas - Milwaukee, WI - Meter-Scale Urban Land Cover Data (MULC) Data (2010)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EnviroAtlas Milwaukee, WI Meter Urban Land Cover (MULC) data and map were generated from USDA NAIP (National Agricultural Imagery Program) four band (red, green,...

  11. SeaWiFS_L3m_SCSP_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  12. SeaWiFS_L3m_R32_PIC_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  13. SeaWiFS_L3b_8D_CHL

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  14. SeaWiFS_L3m_SCWI_RRS_aot_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  15. SeaWiFS_L3m_MC_PAR_9km

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS instrument was launched by Orbital Sciences Corporation on the OrbView-2 (a.k.a. SeaStar) satellite in August 1997, and collected data from September...

  16. A new approach for indoor customer tracking based on a single Wi-Fi connection

    OpenAIRE

    Bai, Yuntian Brian; Wu, Suqin; Ren, Yongli; Ong, Kevin; Retscher, Guenther; Kealy, Allison; Tomko, Martin; Sanderson, Mark; Wu, Hongren; Zhang, Kefei

    2014-01-01

    Wi-Fi and smartphone based location tracking technologies have been widely applied in location based services (LBS). This research is a part of an Australian Research Council (ARC) project required by a large global shopping mall company located in Australia. It aims to develop an effective customer tracking approach for acquiring shopping behavior of customers and providing them better services. Currently, the log data provided by the company only recorded one Wi-Fi connection at a time for ...

  17. WiFi Data Acquisition System Applied to a Photovoltaic Powered Water Pumping Plant

    OpenAIRE

    Sandro César Silveira JUCÁ; Renata Imaculada Soares PEREIRA; Paulo Cesar Marques de CARVALHO

    2015-01-01

    The present paper describes how to design and assemble a low cost online monitoring and WiFi data acquisition system using free software applied to microgeneration based on renewable energy sources. The development of online monitoring systems for microgeneration plants based on renewable energy sources is becoming more important, considering that monitoring and data acquisition systems are applicable in stages of the microgeneration process. The monitoring and data acquisition WiFi system wa...

  18. Insecure Network, Unknown Connection: Understanding Wi-Fi Privacy Assumptions of Mobile Device Users

    OpenAIRE

    Bonné, Bram; Rovelo Ruiz, Gustavo; Quax, Peter; Lamotte, Wim

    2017-01-01

    Smartphones and other mobile devices have proliferated in the past five years. The expectation of mobile device users to always be online has led to Wi-Fi networks being offered by a variety of providers. Using these networks introduces multiple security risks. In this work, we assess to what extent the privacy stance of mobile device users corresponds with their actual behavior by conducting a study with 108 participants. Our methodology consists of monitoring Wi-Fi networks that the partici...

  19. Coexistence of ZigBee-Based WBAN and WiFi for Health Telemonitoring Systems.

    Science.gov (United States)

    Kim, Yena; Lee, SeungSeob; Lee, SuKyoung

    2016-01-01

    The development of telemonitoring via wireless body area networks (WBANs) is an evolving direction in personalized medicine and home-based mobile health. A WBAN consists of small, intelligent medical sensors which collect physiological parameters such as electrocardiogram, electroencephalography, and blood pressure. The recorded physiological signals are sent to a coordinator via wireless technologies, and are then transmitted to a healthcare monitoring center. One of the most widely used wireless technologies in WBANs is ZigBee because it is targeted at applications that require a low data rate and long battery life. However, ZigBee-based WBANs face severe interference problems in the presence of WiFi networks. This problem is caused by the fact that most ZigBee channels overlap with WiFi channels, severely affecting the ability of healthcare monitoring systems to guarantee reliable delivery of physiological signals. To solve this problem, we have developed an algorithm that controls the load in WiFi networks to guarantee the delay requirement for physiological signals, especially for emergency messages, in environments with coexistence of ZigBee-based WBAN and WiFi. Since WiFi applications generate traffic with different delay requirements, we focus only on WiFi traffic that does not have stringent timing requirements. In this paper, therefore, we propose an adaptive load control algorithm for ZigBee-based WBAN/WiFi coexistence environments, with the aim of guaranteeing that the delay experienced by ZigBee sensors does not exceed a maximally tolerable period of time. Simulation results show that our proposed algorithm guarantees the delay performance of ZigBee-based WBANs by mitigating the effects of WiFi interference in various scenarios.

  20. Analysis of MIMO Systems used in planning a 4G-WiMAX Network in Ghana

    OpenAIRE

    Tchao, E. T.; Diawuo, K.; Ofosu, W. K.; Affum, E.

    2013-01-01

    with the increasing demand for mobile data services, Broadband Wireless Access (BWA) is emerging as one of the fastest growing areas within mobile communications. Innovative wireless communication systems, such as WiMAX, are expected to offer highly reliable broadband radio access in order to meet the increasing demands of emerging high speed data and multimedia services. In Ghana, deployment of WiMAX technology has recently begun. Planning these high capacity networks in the presence of mult...

  1. Penentuan Arah Teleskop Digital Melalui Komunikasi Wi-Fi

    Directory of Open Access Journals (Sweden)

    Prima Kurniawan

    2013-09-01

    Full Text Available Teleskop bintang adalah sebuah perangkat instrument yang digunakan untuk melihat benda-benda langit yang jaraknya sangat jauh menjadi terasa dekat. Teleskop yang tersedia pada umumnya belum dilengkapi dengan sistem digital untuk pencitraannya dan otomatisasi untuk penentuan arahnya. Pada tugas akhir ini dibuat suatu sistem digital dan otomatisasi pada teleskop konvensional. Sistem digital digunakan untuk perekaman hasil yang didapatkan oleh teleskop dan ditampilakan pada komputer. Sistem otomatisasi dibuat untuk menentukan pergerakan sudut teleskop dengan sebuah GUI. Mekanik pergerakan teleskop diberikan 2 motor dc sebagai penggerak. Masing-masing motor dc berfungsi untuk menggerakkan tiap sumbu X dan sumbu Y. Digunakan sebuah sistem mikrokontroler menggunakan ATmega 32 sebagai pengolahan data. Fitur ADC mikrokontroler digunakan untuk mengubah data analog perubahan tegangan yang terjadi pada potensiometer menjadi perubahan data digital yang akan dikonversi menjadi nilai pergerakan perubahan sudut. Sistem ini ditambahkan sebuah router yang berfungsi sebagai akses poin untuk jalur pengiriman dan penerimaan data antara komputer dengan mikrokontroler. Ditambahkan sebuah wiznet yang mampu mengkonversi data dari komunikasi serial ke data protokol TCP/IP dan sebaliknya. Pengujian pergerakan sudut sumbu X dilakukan pada sudut 0, 45, 90, 135, 180, 255, 270, 315, dan 360 sedangkan pergerakan sumbu Y dilakukan pada sudut 0, 10, 20, 30, 40, 50, 60, 70, 80, dan 90. Hasil pengujian pada sumbu X dan Y didapatkan beberapa error pada titik-titik tertentu dengan tingkat kesalahan mencapai 3.8% untuk sumbu x dan 2.5% untuk sumbu y. Penentuan pergerakan sudut dilakukan melalui komputer dengan menggunakan komunikasi wi-fi.

  2. Wi-Fi location fingerprinting using an intelligent checkpoint sequence

    Science.gov (United States)

    Retscher, Günther; Hofer, Hannes

    2017-09-01

    For Wi-Fi positioning location fingerprinting is very common but has the disadvantage that it is very labour consuming for the establishment of a database (DB) with received signal strength (RSS) scans measured on a large number of known reference points (RPs). To overcome this drawback a novel approach is developed which uses a logical sequence of intelligent checkpoints (iCPs) instead of RPs distributed in a regular grid. The iCPs are the selected RPs which have to be passed along the way for navigation from a start point A to the destination B. They are twofold intelligent because of the fact that they depend on their meaningful selection and because of their logical sequence in their correct order. Thus, always the following iCP is known due to a vector graph allocation in the DB and only a small limited number of iCPs needs to be tested when matching the current RSS scans. This reduces the required processing time significantly. It is proven that the iCP approach achieves a higher success rate than conventional approaches. In average correct matching results of 90.0% were achieved using a joint DB including RSS scans of all employed smartphones. An even higher success rate is achieved if the same mobile device is used in both the training and positioning phase.

  3. PAPR mitigation algorithms for OFDM WiMAX link

    Science.gov (United States)

    Rashwan, Gasem; Kenshil, Salih; Matin, Mohammad

    2013-09-01

    OFDM has been adopted in many high systems due to its high data rates and to its robust performance in fading channel. OFDM distributes the data among number of carriers which are called subcarriers. The subcarriers must be orthogonal to prevent the carrier from interfering to each other. Features such overcoming ISI (inter-symbol interference) and the complexity of Designing both receiver and transmitter made it ideal technique for both wired and wireless communication as long as optical communications. However, OFDM suffers from a defect called Peak Average power ratio (PAPR). APARP is crucial drawback that limits the way that OFDM functions and reducing or mitigating this factor in wireless and optical environment will help overcome and enhance the OFDM date rate. PAPR is the main cause of inter-carrier interference and high out-of-band power, and consequently Bit error rate BER. We investigate some of the techniques that mitigate the effect of PAPR. These techniques are merged together to provide a better PAPR reduction with the existing techniques. In this paper, we are proposing a new reduction algorithm to minimize the effect of the PAPR. The results and simulation are done in Optisystem V-11 and Matlab environment. These approaches will be applied on WiMAX application and the performances between the different techniques are examined.

  4. Towards Optimal Buffer Size in Wi-Fi Networks

    KAUST Repository

    Showail, Ahmad J.

    2016-01-19

    Buffer sizing is an important network configuration parameter that impacts the quality of data traffic. Falling memory cost and the fallacy that ‘more is better’ lead to over provisioning network devices with large buffers. Over-buffering or the so called ‘bufferbloat’ phenomenon creates excessive end-to-end delay in today’s networks. On the other hand, under-buffering results in frequent packet loss and subsequent under-utilization of network resources. The buffer sizing problem has been studied extensively for wired networks. However, there is little work addressing the unique challenges of wireless environment. In this dissertation, we discuss buffer sizing challenges in wireless networks, classify the state-of-the-art solutions, and propose two novel buffer sizing schemes. The first scheme targets buffer sizing in wireless multi-hop networks where the radio spectral resource is shared among a set of con- tending nodes. Hence, it sizes the buffer collectively and distributes it over a set of interfering devices. The second buffer sizing scheme is designed to cope up with recent Wi-Fi enhancements. It adapts the buffer size based on measured link characteristics and network load. Also, it enforces limits on the buffer size to maximize frame aggregation benefits. Both mechanisms are evaluated using simulation as well as testbed implementation over half-duplex and full-duplex wireless networks. Experimental evaluation shows that our proposal reduces latency by an order of magnitude.

  5. Ubiquity of Wi-Fi: Crowdsensing Properties for Urban Fingerprint Positioning

    Directory of Open Access Journals (Sweden)

    LECA, C. L.

    2017-11-01

    Full Text Available Positioning systems based on location fingerprinting have become an area of intense research, mainly with the aim of providing indoor localization. Many challenges arise when trying to deploy location fingerprinting to an outdoor environment. The main problem is achieving coverage of large outdoor spaces, which needs an intensive data gathering effort. This paper proposes the use of mobile crowdsensing in order to build a fingerprint database consisting of Wi-Fi networks received signal strength measurements. Mobile crowdsensing is represented by the usage of smart-phones equipped with GPS and Wi-Fi sensors for the collection of fingerprints. The primary objective of this work is to prove the feasibility of urban positioning using Wi-Fi crowdsensed data by showing that Wi-Fi networks are ubiquitous in urban areas. We then examine the gathered data and report our findings on challenges in building and maintaining a large-scale fingerprint database, the influence of the data collection method on the Wi-Fi data and the influence of fading on measurements. As Wi-Fi access-points are shown to exhibit mobility, we also propose and analyze methods for detecting and classification of mobile and static access-points.

  6. An Improved Neural Network Training Algorithm for Wi-Fi Fingerprinting Positioning

    Directory of Open Access Journals (Sweden)

    Esmond Mok

    2013-09-01

    Full Text Available Ubiquitous positioning provides continuous positional information in both indoor and outdoor environments for a wide spectrum of location based service (LBS applications. With the rapid development of the low-cost and high speed data communication, Wi-Fi networks in many metropolitan cities, strength of signals propagated from the Wi-Fi access points (APs namely received signal strength (RSS have been cleverly adopted for indoor positioning. In this paper, a Wi-Fi positioning algorithm based on neural network modeling of Wi-Fi signal patterns is proposed. This algorithm is based on the correlation between the initial parameter setting for neural network training and output of the mean square error to obtain better modeling of the nonlinear highly complex Wi-Fi signal power propagation surface. The test results show that this neural network based data processing algorithm can significantly improve the neural network training surface to achieve the highest possible accuracy of the Wi-Fi fingerprinting positioning method.

  7. Influence of smartphone Wi-Fi signals on adipose-derived stem cells.

    Science.gov (United States)

    Lee, Sang-Soon; Kim, Hyung-Rok; Kim, Min-Sook; Park, Sanghoon; Yoon, Eul-Sik; Park, Seung-Ha; Kim, Deok-Woo

    2014-09-01

    The use of smartphones is expanding rapidly around the world, thus raising the concern of possible harmful effects of radiofrequency generated by smartphones. We hypothesized that Wi-Fi signals from smartphones may have harmful influence on adipose-derived stem cells (ASCs). An in vitro study was performed to assess the influence of Wi-Fi signals from smartphones. The ASCs were incubated under a smartphone connected to a Wi-Fi network, which was uploading files at a speed of 4.8 Mbps for 10 hours a day, for a total of 5 days. We constructed 2 kinds of control cells, one grown in 37°C and the other grown in 39°C. After 5 days of Wi-Fi exposure from the smartphone, the cells underwent cell proliferation assay, apoptosis assay, and flow cytometry analysis. Three growth factors, vascular endothelial growth factor, hepatocyte growth factor, and transforming growth factor-β, were measured from ASC-conditioned media. Cell proliferation rate was higher in Wi-Fi-exposed cells and 39°C control cells compared with 37°C control cells. Apoptosis assay, flow cytometry analysis, and growth factor concentrations showed no remarkable differences among the 3 groups. We could not find any harmful effects of Wi-Fi electromagnetic signals from smartphones. The increased proliferation of ASCs under the smartphone, however, might be attributable to the thermal effect.

  8. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks

    Directory of Open Access Journals (Sweden)

    Zhi-An Deng

    2016-09-01

    Full Text Available To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR, and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF. For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning.

  9. Continuous Indoor Positioning Fusing WiFi, Smartphone Sensors and Landmarks.

    Science.gov (United States)

    Deng, Zhi-An; Wang, Guofeng; Qin, Danyang; Na, Zhenyu; Cui, Yang; Chen, Juan

    2016-09-05

    To exploit the complementary strengths of WiFi positioning, pedestrian dead reckoning (PDR), and landmarks, we propose a novel fusion approach based on an extended Kalman filter (EKF). For WiFi positioning, unlike previous fusion approaches setting measurement noise parameters empirically, we deploy a kernel density estimation-based model to adaptively measure the related measurement noise statistics. Furthermore, a trusted area of WiFi positioning defined by fusion results of previous step and WiFi signal outlier detection are exploited to reduce computational cost and improve WiFi positioning accuracy. For PDR, we integrate a gyroscope, an accelerometer, and a magnetometer to determine the user heading based on another EKF model. To reduce accumulation error of PDR and enable continuous indoor positioning, not only the positioning results but also the heading estimations are recalibrated by indoor landmarks. Experimental results in a realistic indoor environment show that the proposed fusion approach achieves substantial positioning accuracy improvement than individual positioning approaches including PDR and WiFi positioning.

  10. Calibration of SeaWiFS after two years on orbit

    Science.gov (United States)

    Barnes, Robert A.; McClain, Charles R.

    1999-12-01

    The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) was launched on 1 August 1997, and the first Earth images were taken on 4 September 1997. Regular, daily measurements of the sun, via the onboard diffuser, started on 9 September 1997 and regular, monthly measurements of the moon on November 14, 1997. These lunar measurements, as first reported at EUROPTO'98, provide a highly sensitive method for determining the change in the radiometric sensitivity of SeaWiFS. The prelaunch radiometric calibration used by SeaWiFS was performed in the Spring of 1997 at the spacecraft manufacturer's facility. The calibration measurements were made by a team from the National Institute of Standards and Technology (NIST) and the SeaWiFS Project. The uncertainties in this calibration range from 2% to 3% for the eight SeaWiFS bands. In addition, a set of outdoor measurements of the sun were made at the instrument manufacturer's facility in November 1993, just before the delivery of SeaWiFS to the spacecraft manufacturer. These solar measurements, using the instrument's diffuser, were combined with a separate set of solar radiometer measurements to determine the transmittance of the atmosphere. At the start of on-orbit measurements by SeaWiFS, solar measurements were made again by the instrument. These two sets of measurements make up the transfer-to-orbit experiment. From the ground measurements, the outputs of the SeaWiFS bands on orbit were predicted. For each band, the output from the initial on-orbit measurements agree with the predicted values by 21/2% or less. The uncertainties for the transfer-to-orbit experiment are estimated to be approximately 3% to 4%. From 14 November 1997 to 29 June 1999, SeaWiFS has made 20 measurements of the moon. The analysis of lunar measurements presented here has minor modifications to that presented at EUROPTO'98. The trend lines from the current analysis have been extrapolated back from 14 November 1997 to 4 September 1997 to describe the changes

  11. Effects of repeated restraint stress and WiFi signal exposure on behavior and oxidative stress in rats.

    Science.gov (United States)

    Othman, Haifa; Ammari, Mohamed; Sakly, Mohsen; Abdelmelek, Hafedh

    2017-10-01

    Today, due to technology development and aversive events of daily life, Human exposure to both radiofrequency and stress is unavoidable. This study investigated the co-exposure to repeated restraint stress and WiFi signal on cognitive function and oxidative stress in brain of male rats. Animals were divided into four groups: Control, WiFi-exposed, restrained and both WiFi-exposed and restrained groups. Each of WiFi exposure and restraint stress occurred 2 h (h)/day during 20 days. Subsequently, various tests were carried out for each group, such as anxiety in elevated plus maze, spatial learning abilities in the water maze, cerebral oxidative stress response and cholinesterase activity in brain and serum. Results showed that WiFi exposure and restraint stress, alone and especially if combined, induced an anxiety-like behavior without impairing spatial learning and memory abilities in rats. At cerebral level, we found an oxidative stress response triggered by WiFi and restraint, per se and especially when combined as well as WiFi-induced increase in acetylcholinesterase activity. Our results reveal that there is an impact of WiFi signal and restraint stress on the brain and cognitive processes especially in elevated plus maze task. In contrast, there are no synergistic effects between WiFi signal and restraint stress on the brain.

  12. The Architecture of WiFi-Based WSN for AMR System and E-HWMP Routing Protocol

    Directory of Open Access Journals (Sweden)

    Li LI

    2014-02-01

    Full Text Available With the development of SoC technology in recent years, the ultra-low power WiFi System on SoC Chip has emerged. As a result, WiFi-based Wireless Sensor Networks come into use, especially used in Automatic Meter Reading. While because the nodes of Wireless Sensor Networks have limited energy supply, smaller storage capability and slower calculation ability, the current WiFi technology cannot be directly applied to WiFi-based Wireless Sensor Networks. The protocols should be upgraded and the security algorithms should be improved to meet the new requests. Firstly, this article describes the network architecture of WiFi-based WSN for AMR system and discusses the reason for using this analogous Mesh architecture. Secondly, the new Hardware architecture of WiFi-based WSN node is designed to realize the AMR system and verify the research work. The node can collect the data of power meter by WiFi and can be powered by a Lithium Battery. Thirdly, on the basis of study work of WiFi original routing protocol HWMP, a new method on improving the energy saving ability of HWMP to adapt the new features of WiFi-based WSN is proposed. And the simulation work on the new routing protocol E-HWMP has been done with NS2 and the simulation results show that the life cycle of the network has been extended to some degree.

  13. Advanced Integration of WiFi and Inertial Navigation Systems for Indoor Mobile Positioning

    Directory of Open Access Journals (Sweden)

    Evennou Frédéric

    2006-01-01

    Full Text Available This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navigation systems (INS are used for positioning and attitude determination in a wide range of applications. Over the last few years, a number of low-cost inertial sensors have become available. Although they exhibit large errors, WiFi measurements can be used to correct the drift weakening the navigation based on this technology. On the other hand, INS sensors can interact with the WiFi positioning system as they provide high-accuracy real-time navigation. A structure based on a Kalman filter and a particle filter is proposed. It fuses the heterogeneous information coming from those two independent technologies. Finally, the benefits of the proposed architecture are evaluated and compared with the pure WiFi and INS positioning systems.

  14. Wi-Fi and health: review of current status of research.

    Science.gov (United States)

    Foster, Kenneth R; Moulder, John E

    2013-12-01

    This review summarizes the current state of research on possible health effects of Wi-Fi (a commercial name for IEEE 802.11-compliant wireless networking). In response to public concerns about health effects of Wi-Fi and wireless networks and calls by government agencies for research on possible health and safety issues with the technology, a considerable amount of technology-specific research has been completed. A series of high quality engineering studies have provided a good, but not complete, understanding of the levels of radiofrequency (RF) exposure to individuals from Wi-Fi. The limited number of technology-specific bioeffects studies done to date are very mixed in terms of quality and outcome. Unequivocally, the RF exposures from Wi-Fi and wireless networks are far below U.S. and international exposure limits for RF energy. While several studies report biological effects due to Wi-Fi-type exposures, technical limitations prevent drawing conclusions from them about possible health risks of the technology. The review concludes with suggestions for future research on the topic.

  15. Indoor Map Aided Wi-Fi Integrated Lbs on Smartphone Platforms

    Science.gov (United States)

    Yu, C.; El-Sheimy, N.

    2017-09-01

    In this research, an indoor map aided INS/Wi-Fi integrated location based services (LBS) applications is proposed and implemented on smartphone platforms. Indoor map information together with measurements from an inertial measurement unit (IMU) and Received Signal Strength Indicator (RSSI) value from Wi-Fi are collected to obtain an accurate, continuous, and low-cost position solution. The main challenge of this research is to make effective use of various measurements that complement each other without increasing the computational burden of the system. The integrated system in this paper includes three modules: INS, Wi-Fi (if signal available) and indoor maps. A cascade structure Particle/Kalman filter framework is applied to combine the different modules. Firstly, INS position and Wi-Fi fingerprint position integrated through Kalman filter for estimating positioning information. Then, indoor map information is applied to correct the error of INS/Wi-Fi estimated position through particle filter. Indoor tests show that the proposed method can effectively reduce the accumulation positioning errors of stand-alone INS systems, and provide stable, continuous and reliable indoor location service.

  16. An Improved WiFi Indoor Positioning Algorithm by Weighted Fusion.

    Science.gov (United States)

    Ma, Rui; Guo, Qiang; Hu, Changzhen; Xue, Jingfeng

    2015-08-31

    The rapid development of mobile Internet has offered the opportunity for WiFi indoor positioning to come under the spotlight due to its low cost. However, nowadays the accuracy of WiFi indoor positioning cannot meet the demands of practical applications. To solve this problem, this paper proposes an improved WiFi indoor positioning algorithm by weighted fusion. The proposed algorithm is based on traditional location fingerprinting algorithms and consists of two stages: the offline acquisition and the online positioning. The offline acquisition process selects optimal parameters to complete the signal acquisition, and it forms a database of fingerprints by error classification and handling. To further improve the accuracy of positioning, the online positioning process first uses a pre-match method to select the candidate fingerprints to shorten the positioning time. After that, it uses the improved Euclidean distance and the improved joint probability to calculate two intermediate results, and further calculates the final result from these two intermediate results by weighted fusion. The improved Euclidean distance introduces the standard deviation of WiFi signal strength to smooth the WiFi signal fluctuation and the improved joint probability introduces the logarithmic calculation to reduce the difference between probability values. Comparing the proposed algorithm, the Euclidean distance based WKNN algorithm and the joint probability algorithm, the experimental results indicate that the proposed algorithm has higher positioning accuracy.

  17. Advanced Integration of WiFi and Inertial Navigation Systems for Indoor Mobile Positioning

    Science.gov (United States)

    Evennou, Frédéric; Marx, François

    2006-12-01

    This paper presents an aided dead-reckoning navigation structure and signal processing algorithms for self localization of an autonomous mobile device by fusing pedestrian dead reckoning and WiFi signal strength measurements. WiFi and inertial navigation systems (INS) are used for positioning and attitude determination in a wide range of applications. Over the last few years, a number of low-cost inertial sensors have become available. Although they exhibit large errors, WiFi measurements can be used to correct the drift weakening the navigation based on this technology. On the other hand, INS sensors can interact with the WiFi positioning system as they provide high-accuracy real-time navigation. A structure based on a Kalman filter and a particle filter is proposed. It fuses the heterogeneous information coming from those two independent technologies. Finally, the benefits of the proposed architecture are evaluated and compared with the pure WiFi and INS positioning systems.

  18. QoS Management and Control for an All-IP WiMAX Network Architecture: Design, Implementation and Evaluation

    Directory of Open Access Journals (Sweden)

    Thomas Michael Bohnert

    2008-01-01

    Full Text Available The IEEE 802.16 standard provides a specification for a fixed and mobile broadband wireless access system, offering high data rate transmission of multimedia services with different Quality-of-Service (QoS requirements through the air interface. The WiMAX Forum, going beyond the air interface, defined an end-to-end WiMAX network architecture, based on an all-IP platform in order to complete the standards required for a commercial rollout of WiMAX as broadband wireless access solution. As the WiMAX network architecture is only a functional specification, this paper focuses on an innovative solution for an end-to-end WiMAX network architecture offering in compliance with the WiMAX Forum specification. To our best knowledge, this is the first WiMAX architecture built by a research consortium globally and was performed within the framework of the European IST project WEIRD (WiMAX Extension to Isolated Research Data networks. One of the principal features of our architecture is support for end-to-end QoS achieved by the integration of resource control in the WiMAX wireless link and the resource management in the wired domains in the network core. In this paper we present the architectural design of these QoS features in the overall WiMAX all-IP framework and their functional as well as performance evaluation. The presented results can safely be considered as unique and timely for any WiMAX system integrator.

  19. Comparative Performance Evaluation of TCP Variants in WiMAX (and WLANs Network Configurations

    Directory of Open Access Journals (Sweden)

    Konstantinos Tsiknas

    2012-01-01

    Full Text Available An important application for the IEEE 802.16 technology (also called WiMAX is to provide high-speed access to the Internet where the transmission control protocol (TCP is the core transport protocol. In this paper we study through extensive simulation scenarios the performance characteristics of five representative TCP schemes, namely, TCP New Reno, Vegas, Veno, Westwood, and BIC, in WiMAX (and WLANs networks, under the conditions of correlated wireless errors, asymmetric end-to-end capabilities, and link congestion. The target is to evaluate how the above conditions would affect the TCP congestion control and suggest the best schemes to be employed in WiMAX networks.

  20. QoS Provisioning Techniques for Future Fiber-Wireless (FiWi Access Networks

    Directory of Open Access Journals (Sweden)

    Martin Maier

    2010-04-01

    Full Text Available A plethora of enabling optical and wireless access-metro network technologies have been emerging that can be used to build future-proof bimodal fiber-wireless (FiWi networks. Hybrid FiWi networks aim at providing wired and wireless quad-play services over the same infrastructure simultaneously and hold great promise to mitigate the digital divide and change the way we live and work by replacing commuting with teleworking. After overviewing enabling optical and wireless network technologies and their QoS provisioning techniques, we elaborate on enabling radio-over-fiber (RoF and radio-and-fiber (R&F technologies. We describe and investigate new QoS provisioning techniques for future FiWi networks, ranging from traffic class mapping, scheduling, and resource management to advanced aggregation techniques, congestion control, and layer-2 path selection algorithms.

  1. Spectrum Sensing Experimentation for LTE and WiFi Unlicensed Band Operation

    Directory of Open Access Journals (Sweden)

    N. Milošević

    2016-11-01

    Full Text Available If several different systems operate in the same frequency band, a coordination between them is needed for effective use of the available spectrum. The coordination is especially important if the systems are not designed to operate in such an environment. The very important initial phase of the coordination process is acquiring of the spectrum usage map or spectrum sensing. The paper describes the spectrum sensing experimentation in the unlicensed 5 GHz band during the WiFi or LTE transmission. It describes the experiment workflow and depicts the obtained results. The experiments were performed at NITOS testbed at the University of Thessaly, Greece, and show that it is possible to determine whether WiFi or LTE transmission is sensed. Therefore, based on spectrum sensing it will be possible to coordinate a shared access of WiFi and LTE users in the unlicensed 5 GHz band.

  2. Experimental verification of a radiofrequency power model for Wi-Fi technology.

    Science.gov (United States)

    Fang, Minyu; Malone, David

    2010-04-01

    When assessing the power emitted from a Wi-Fi network, it has been observed that these networks operate at a relatively low duty cycle. In this paper, we extend a recently introduced model of emitted power in Wi-Fi networks to cover conditions where devices do not always have packets to transmit. We present experimental results to validate the original model and its extension by developing approximate, but practical, testbed measurement techniques. The accuracy of the models is confirmed, with small relative errors: less than 5-10%. Moreover, we confirm that the greatest power is emitted when the network is saturated with traffic. Using this, we give a simple technique to quickly estimate power output based on traffic levels and give examples showing how this might be used in practice to predict current or future power output from a Wi-Fi network.

  3. Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

    Science.gov (United States)

    Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

    2016-01-01

    Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

  4. To promote public acceptance of nuclear energy by WiN-JAPAN

    International Nuclear Information System (INIS)

    Kuroiwa, Haruko; Kobayashi, Yoko; Ogawa, Junko

    2011-01-01

    Women in Nuclear Japan (WiN-J) has been striving to promote activities that increase public acceptance of nuclear energy especially by women. According to a public opinion poll in 2009 by the Cabient Office, Government of Japan, the ratio of men who have confidence in nuclear power plant safety was 52.1%, while the ratio of females was only 32.5%. And the ratio of negative feeling about nuclear power among males was 45.8%, while the ratio of females was 61.2%. This indicates the necessity of communication to females to encourage them to accept nuclear power. WiN-J developed two methods of communication with the public and young people about the benefits of nuclear energy and the applications of radiation in many aspects of the life. The first is town hall meetings, and the other is education for university students in the style of a Science Cafe. Surprisingly, present university student never studied about nuclear energy when they were elementary or junior high school students. However, those students will have to educate their own children to use energy wisely in consideration of the limited energy resources in the coming years. WiN-J, therefore, gives them some relevant lectures on nuclear energy and radiation. Also WiN-J can be the models for female university students who have issues such as marriage, pregnancy, promotions, and transfers which can be discussed. We have to increase the numbers of female nuclear engineers to promote public trust in the safety of nuclear power plants. For this purpose, WiN-J encourages female university students to enter the nuclear industry. We recognize that to gain people's understanding of and trust in nuclear energy may take a long time. WiN-J will continue to fulfill our challenging mission for the peaceful use of nuclear energy. (author)

  5. A Self-Adaptive Model-Based Wi-Fi Indoor Localization Method.

    Science.gov (United States)

    Tuta, Jure; Juric, Matjaz B

    2016-12-06

    This paper presents a novel method for indoor localization, developed with the main aim of making it useful for real-world deployments. Many indoor localization methods exist, yet they have several disadvantages in real-world deployments-some are static, which is not suitable for long-term usage; some require costly human recalibration procedures; and others require special hardware such as Wi-Fi anchors and transponders. Our method is self-calibrating and self-adaptive thus maintenance free and based on Wi-Fi only. We have employed two well-known propagation models-free space path loss and ITU models-which we have extended with additional parameters for better propagation simulation. Our self-calibrating procedure utilizes one propagation model to infer parameters of the space and the other to simulate the propagation of the signal without requiring any additional hardware beside Wi-Fi access points, which is suitable for real-world usage. Our method is also one of the few model-based Wi-Fi only self-adaptive approaches that do not require the mobile terminal to be in the access-point mode. The only input requirements of the method are Wi-Fi access point positions, and positions and properties of the walls. Our method has been evaluated in single- and multi-room environments, with measured mean error of 2-3 and 3-4 m, respectively, which is similar to existing methods. The evaluation has proven that usable localization accuracy can be achieved in real-world environments solely by the proposed Wi-Fi method that relies on simple hardware and software requirements.

  6. What Can WiN Learn From Other Male Dominated Industries

    International Nuclear Information System (INIS)

    Thomas, C.

    2015-01-01

    Thomas Thor Associates is an Executive Recruitment company solely dedicated to the Nuclear industry. We have been involved with WiN UK in 2014–2015 to help them develop their own organization, this research was part of our partnership. The main purpose of this paper is to provide a clear picture of the techniques that are used by organizations similar to WiN, and business in other industries that are similar to Nuclear, to attract more women to pursue a career in a particular industry, and to support retention and career progression of women in these industries. This paper has taken a look at all industries that require technical and engineering staff, after which the Mining, Oil and Gas, Petro-chemicals, Rail, Renewable Energy, Technology and Construction industries were found to show most similarities with Nuclear, in terms of the technical staff required and their structure on gender diversity. From here, case studies of industry organizations and professional business have been prepared in order to inform WiN of best practice in these industries and provide a benchmark for future WiN operations. Finally, the report results into giving recommendations on projects WiN could add to their current approach to achieve their objectives. The recommendations are based on the results from the case studies, focusing on attracting, recruiting, retaining and developing female professionals. In summary, the recommendations are to: highlight potential career paths for women in Nuclear, educate women on Nuclear, support the development of women and to help companies to increase their bottom line by getting WiN certified. (author)

  7. SeaWiFS technical report series. Volume 11: Analysis of selected orbit propagation models for the SeaWiFS mission

    Science.gov (United States)

    Patt, Frederick S.; Hoisington, Charles M.; Gregg, Watson W.; Coronado, Patrick L.; Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Indest, A. W. (Editor)

    1993-01-01

    An analysis of orbit propagation models was performed by the Mission Operations element of the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) Project, which has overall responsibility for the instrument scheduling. The orbit propagators selected for this analysis are widely available general perturbations models. The analysis includes both absolute accuracy determination and comparisons of different versions of the models. The results show that all of the models tested meet accuracy requirements for scheduling and data acquisition purposes. For internal Project use the SGP4 propagator, developed by the North American Air Defense (NORAD) Command, has been selected. This model includes atmospheric drag effects and, therefore, provides better accuracy. For High Resolution Picture Transmission (HRPT) ground stations, which have less stringent accuracy requirements, the publicly available Brouwer-Lyddane models are recommended. The SeaWiFS Project will make available portable source code for a version of this model developed by the Data Capture Facility (DCF).

  8. Positioning indoors with Wi-Fi devices of low-cost; Posicionamento em ambientes internos com dispositivos wi-fi de baixo custo

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Fabricio M.; Farias, Marcos S.; Carvalho, Paulo Victor R. de, E-mail: fabricio_mv1@hotmail.com, E-mail: msantana@ien.gov.br, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Serviço de Instrumentação

    2017-07-01

    The rhythm of research development linked to location tracking is highly linked with the advancement of wireless sensor network and wireless technologies. A classic example is the Global Positioning System (GPS), where satellites are used to send signals to receivers on earth that use these signals to compute navigation information. However, as communication between the satellites and GPS receivers require radio propagation in line of sight, the GPS system usually only works outdoors. For the growing interest in research to position tracking indoors, you must use wireless devices based on Bluetooth or Wi-Fi technology (IEEE 802.11). The aim of this work is to show the development of applications using new Wi-Fi devices (ESP8266) for the estimation of positioning and location indoors.

  9. Inferring Person-to-person Proximity Using WiFi Signals

    DEFF Research Database (Denmark)

    Sapiezynski, Piotr; Stopczynski, Arkadiusz; Wind, David Kofoed

    2017-01-01

    scale is a technical challenge and many commonly used approaches—including RFID badges or Bluetooth scanning—offer only limited scalability. Here we show that it is possible, in a scalable and robust way, to accurately infer person-to-person physical proximity from the lists of WiFi access points...... measured by smartphones carried by the two individuals. Based on a longitudinal dataset of approximately 800 participants with ground-truth interactions collected over a year, we show that our model performs better than the current state-of-the-art. Our results demonstrate the value of WiFi signals...

  10. Access for Internet of Things using Smartphone as a Gateway utilizing LTE and WiFi

    DEFF Research Database (Denmark)

    Mathur, Prateek; Nielsen, Rasmus Hjorth; Prasad, Neeli R.

    2016-01-01

    Communicating the Internet of Things (IoT) data relying on Long-Term Evolution (LTE) and WiFi has been been presented in the relevant literature. However, this necessitates devices to have LTE/WiFi capability of their own, that has limitations in the form of power consumption, and radio access...... the data to the Internet. In this paper we present a system model wherein the smartphone functions as a gateway for the IoT devices operating on NFC, ZigBee and Bluetooth. The smartphone functioning as a gateway for transferring IoT data. The system modelled in the form of a Markov Chain based...

  11. RSSI BASED LOCATION ESTIMATION IN A WI-FI ENVIRONMENT: AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    M. Ganesh Madhan

    2014-12-01

    Full Text Available In real life situations, location estimation of moving objects, armed personnel are of great importance. In this paper, we have attempted to locate targets which are mobile in a Wi-Fi environment. Radio Frequency (RF localization techniques based on Received Signal Strength Indication (RSSI algorithms are used. This study utilises Wireless Mon tool, software to provide complete technical information regarding received signal strength obtained from different wireless access points available in a campus Wi-Fi environment, considered for the study. All simulations have been done in MATLAB. The target location estimated by this approach agrees well with the actual GPS data.

  12. The SeaWiFS Quality Monitor: A Portable Field Calibration Light Source

    Science.gov (United States)

    Shaw, Ping-Shine; Johnson, B. Carol; Hooker, Stanford B.; Lynch, Don

    1997-01-01

    A portable and stable source, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Quality Monitor, has been developed for use as a field instrument. The source can be used with either radiance- or irradiance-measuring sensors to transfer the laboratory calibration to the field so that the stability of the sensors can be monitored during the experiment. Temperature-controlled silicon photodiodes with colored glass filters are used to monitor the stability of the SeaWiFS Quality Monitor.

  13. Cognitive radio-based transmission energy management in Wi-Fi nodes

    CSIR Research Space (South Africa)

    Olwal, TO

    2012-10-01

    Full Text Available following the adoption of the proposed CR-TEM method. The execution of the CR-TEM fosters more users? adoption of the internet services and a corresponding network gain. Figure 5: Expected network performance Fi 3 M d l f C TEM i Wi Fi d Fi 5 E d k f....kashan.co.za] INTRODUCTION The recent increased demand for various internet services, shown in Figure 1, to be delivered through energy-efficient wireless infrastructures such as Wi-Fi routers has compelled the need for a new research & development (R&D) paradigm...

  14. Dual Y-Shaped Monopole Antenna for Dual-Band WLAN/WiMAX Operations

    Directory of Open Access Journals (Sweden)

    Huiqing Zhai

    2014-01-01

    Full Text Available A dual-band design of monopole antenna with two coupled Y-shaped strips for WLAN/WiMAX applications is presented. By the introduction of dual Y-shaped strips, two separated impedance bandwidths of 22.4% (3.28~4.10 GHz and 19.2% (4.90~5.94 GHz can be obtained to meet the specifications of the WLAN/WiMAX communication band applications. The proposed antenna is successfully simulated, designed, and measured, demonstrating the matched impedance and good radiation characteristics with an overall dimension of 17.7×26×1 mm3.

  15. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones

    Directory of Open Access Journals (Sweden)

    Huaiyu Li

    2015-12-01

    Full Text Available Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel “quasi-dynamic” Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the “process-level” fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move.

  16. Safe at Any Speed: Securing Your Wi-Fi Network Is Easier and More Important than You Might Think

    Science.gov (United States)

    Branzburg, Jeffrey

    2007-01-01

    In this article, the author relates how he discovered that not all Wi-Fi networks are secure. As such, he developed several strategies on how he can be secured whenever he connects to the Internet through a Wi-Fi connection. He discusses how one can change passwords, explains the process of encryption, and provides suggestions on other security…

  17. An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones.

    Science.gov (United States)

    Li, Huaiyu; Chen, Xiuwan; Jing, Guifei; Wang, Yuan; Cao, Yanfeng; Li, Fei; Zhang, Xinlong; Xiao, Han

    2015-12-11

    Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF) algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel "quasi-dynamic" Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the "process-level" fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR) positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move.

  18. Converged delivery of WiMAX and wireline services over an extended reach passive optical access network

    DEFF Research Database (Denmark)

    Osadchiy, Alexey Vladimirovich; Prince, Kamau; Tafur Monroy, Idelfonso

    2010-01-01

    In this paper we present long-reach fiber access links supporting transmission of Worldwide Interoperability for Microwave Access (WiMAX) compliant signals. We present bi-directional full-duplex transmission of 256-state quadrature amplitude modulation (256-QAM) modulated WiMAX-compliant signals ...

  19. 78 FR 39608 - Safety Zone; Summer in the City Water Ski Show; Fox River, Green Bay, WI

    Science.gov (United States)

    2013-07-02

    ...-AA00 Safety Zone; Summer in the City Water Ski Show; Fox River, Green Bay, WI AGENCY: Coast Guard, DHS... and three boats, operating within the main channel of the Fox River. The Captain of the Port, Lake... River in Green Bay, WI. This safety zone is intended to restrict vessels from a portion of the Fox River...

  20. SeaWiFS Deep Blue Aerosol Optical Thickness Monthly Level 3 Climatology Data Gridded at 1.0 Degrees V004

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS Deep Blue Level 3 Monthly Climatology Product contains monthly global climatology gridded (1 x 1 deg) data derived from SeaWiFS Deep Blue Level 3 monthly...

  1. 78 FR 42016 - Safety Zone; Discovery World Fireworks, Milwaukee Harbor, Milwaukee, WI

    Science.gov (United States)

    2013-07-15

    ... economically affect it. 3. Assistance for Small Entities Under section 213(a) of the Small Business Regulatory...-AA00 Safety Zone; Discovery World Fireworks, Milwaukee Harbor, Milwaukee, WI AGENCY: Coast Guard, DHS... Milwaukee Harbor due to 4 fireworks displays at Discovery World Pier. This safety zone is necessary to...

  2. Chlorophyll-a, Orbview-2 SeaWiFS, 0.0125 degrees, West US

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes chlorophyll-a concentration images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the Orbview-2 satellite. Because data is...

  3. Chlorophyll-a, Orbview-2 SeaWiFS, 0.04167 degrees, Alaska, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA GSFC Ocean Color Web distributes science-quality chlorophyll-a concentration data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the Orbview-2...

  4. Insecure Network, Unknown Connection: Understanding Wi-Fi Privacy Assumptions of Mobile Device Users

    Directory of Open Access Journals (Sweden)

    Bram Bonné

    2017-07-01

    Full Text Available Smartphones and other mobile devices have proliferated in the past five years. The expectation of mobile device users to always be online has led to Wi-Fi networks being offered by a variety of providers. Using these networks introduces multiple security risks. In this work, we assess to what extent the privacy stance of mobile device users corresponds with their actual behavior by conducting a study with 108 participants. Our methodology consists of monitoring Wi-Fi networks that the participants’ devices connect to and the connections made by apps on these devices, for a period of 30 days. Afterwards, participants are surveyed about their awareness and privacy sensitiveness. We show that while a higher expertise in computer networks corresponds to more awareness about the connections made by apps, neither this expertise nor the actual privacy stance of the participant translates to better security habits. Moreover, participants in general were unaware about a significant part of connections made by apps on their devices, a matter that is worsened by the fact that one third of Wi-Fi networks that participants connect to do not have any security enabled. Based on our results, we provide recommendations to network providers, developers and users on how to improve Wi-Fi security for mobile devices.

  5. Klimatisering van de energieproducerende tuinbouwkas met FiWiHex warmtewisselaars : vooronderzoek Energie producerende kas

    NARCIS (Netherlands)

    Campen, J.B.; Zwart, de H.F.

    2005-01-01

    De stuurgroep 'Kas als energiebron' beoogt de realisatie van een pilotproject van een energieproducerende kas. In de in dit rapport beschreven uitvoeringsvorm wordt gebruik gemaakt van hoog-rendement FiWiHEx warmtewisselaars. Verkennende onderzoeken en initiërend design hebben geleid tot een eerste

  6. 75 FR 51851 - Weather Shield Manufacturing, Inc., Corporate Office, Medford, WI; Notice of Revised...

    Science.gov (United States)

    2010-08-23

    ...] [FR Doc No: 2010-20791] DEPARTMENT OF LABOR Employment and Training Administration [TA-W-64,725] Weather Shield Manufacturing, Inc., Corporate Office, Medford, WI; Notice of Revised Determination on... Adjustment Assistance (ATAA) on behalf of workers of Weather Shield Manufacturing, Inc., Corporate Office...

  7. Device-Free Passive Identity Identification via WiFi Signals.

    Science.gov (United States)

    Lv, Jiguang; Yang, Wu; Man, Dapeng

    2017-11-02

    Device-free passive identity identification attracts much attention in recent years, and it is a representative application in sensorless sensing. It can be used in many applications such as intrusion detection and smart building. Previous studies show the sensing potential of WiFi signals in a device-free passive manner. It is confirmed that human's gait is unique from each other similar to fingerprint and iris. However, the identification accuracy of existing approaches is not satisfactory in practice. In this paper, we present Wii, a device-free WiFi-based Identity Identification approach utilizing human's gait based on Channel State Information (CSI) of WiFi signals. Principle Component Analysis (PCA) and low pass filter are applied to remove the noises in the signals. We then extract several entities' gait features from both time and frequency domain, and select the most effective features according to information gain. Based on these features, Wii realizes stranger recognition through Gaussian Mixture Model (GMM) and identity identification through a Support Vector Machine (SVM) with Radial Basis Function (RBF) kernel. It is implemented using commercial WiFi devices and evaluated on a dataset with more than 1500 gait instances collected from eight subjects walking in a room. The results indicate that Wii can effectively recognize strangers and can achieves high identification accuracy with low computational cost. As a result, Wii has the potential to work in typical home security systems.

  8. Unscented Kalman Filter Algorithm for WiFi-PDR Integrated Indoor Positioning

    Directory of Open Access Journals (Sweden)

    CHEN GuoLiang

    2015-12-01

    Full Text Available Indoor positioning still faces lots of fundamental technical problems although it has been widely applied. A novel indoor positioning technology by using the smart phone with the assisting of the widely available and economically signals of WiFi is proposed. It also includes the principles and characteristics in indoor positioning. Firstly, improve the system's accuracy by fusing the WiFi fingerprinting positioning and PDR (ped estrian dead reckoning positioning with UKF (unscented Kalman filter. Secondly, improve the real-time performance by clustering the WiFi fingerprinting with k-means clustering algorithm. An investigation test was conducted at the indoor environment to learn about its performance on a HUAWEI P6-U06 smart phone. The result shows that compared to the pattern-matching system without clustering, an average reduction of 51% in the time cost can be obtained without degrading the positioning accuracy. When the state of personnel is walking, the average positioning error of WiFi is 7.76 m, the average positioning error of PDR is 4.57 m. After UKF fusing, the system's average positioning error is down to 1.24 m. It shows that the algorithm greatly improves the system's real-time and positioning accuracy.

  9. Complementing Security Breach of Authentication by Using Shared Authentication Information in Mobile WiMAX Networks

    Science.gov (United States)

    Kim, Youngwook; Lim, Hyoung-Kyu; Bahk, Saewoong

    The signalling protocol vulnerability opens DDoS problem in Mobile WiMAX networks. This letter proposes an authentication method that uses the unrevealed upper 64bits of Cipher-based MAC as a solution. It runs for MSs in idle mode and reduces the calculation complexity by 59% under DDoS attack while incurring 1% overhead under normal condition.

  10. 78 FR 20714 - Union Pacific Railroad Company-Abandonment Exemption-in Dunn County, WI.

    Science.gov (United States)

    2013-04-05

    ... Surface Transportation Board Union Pacific Railroad Company--Abandonment Exemption--in Dunn County, WI. Union Pacific Railroad Company (UP) filed a verified notice of exemption under 49 CFR part 1152 subpart... the Board should be sent to UP's representative: Mack H. Shumate, Jr., Senior General Attorney, Union...

  11. 76 FR 46626 - Safety Zone; Discovery World Private Wedding Firework Displays, Milwaukee, WI

    Science.gov (United States)

    2011-08-03

    ... could better evaluate its effects on them and participate in the rulemaking process. Small businesses...-AA00 Safety Zone; Discovery World Private Wedding Firework Displays, Milwaukee, WI AGENCY: Coast Guard... the public interest. Background and Purpose The Discovery World Private Wedding fireworks are a City...

  12. Considerations for Using Personal Wi-Fi Enabled Devices as "Clickers" in a Large University Class

    Science.gov (United States)

    Katz, Larry; Hallam, Megan C.; Duvall, Michael M.; Polsky, Zoe

    2017-01-01

    Interactive student response systems, commonly referred to as clickers, have increased in popularity in higher education classrooms as a means to improve engagement and enhance learning. Clicker systems come with handheld devices as well as a radio frequency receiver. A Wi-Fi connection to the receiver is possible, enabling students to use their…

  13. PILA: Sub-Meter Localization Using CSI from Commodity Wi-Fi Devices.

    Science.gov (United States)

    Tian, Zengshan; Li, Ze; Zhou, Mu; Jin, Yue; Wu, Zipeng

    2016-10-10

    The aim of this paper is to present a new indoor localization approach by employing the Angle-of-arrival (AOA) and Received Signal Strength (RSS) measurements in Wi-Fi network. To achieve this goal, we first collect the Channel State Information (CSI) by using the commodity Wi-Fi devices with our designed three antennas to estimate the AOA of Wi-Fi signal. Second, we propose a direct path identification algorithm to obtain the direct signal path for the sake of reducing the interference of multipath effect on the AOA estimation. Third, we construct a new objective function to solve the localization problem by integrating the AOA and RSS information. Although the localization problem is non-convex, we use the Second-order Cone Programming (SOCP) relaxation approach to transform it into a convex problem. Finally, the effectiveness of our approach is verified based on the prototype implementation by using the commodity Wi-Fi devices. The experimental results show that our approach can achieve the median error 0.7 m in the actual indoor environment.

  14. Using Wi-Fi to Save Energy via P2P Remote Execution

    DEFF Research Database (Denmark)

    Kristensen, Mads Darø; Bouvin, Niels Olof

    2010-01-01

    tasks. This paper presents energy measurements of a modern mobile computing device, showing that utilising the relatively large CPU of such a device is very expensive - even more so than using Wi-Fi. Experiments performed with the Scavenger cyber foraging system are presented; a system enabling easy...

  15. SKIN - Embodied Navigation Through WiFi Traffic Using Vibro-Tactile Feedback

    DEFF Research Database (Denmark)

    van den Boogaard, Bas; Orsted Jensen, Louise; Nielsen, Stefan Engelbrecht

    2018-01-01

    In today’s world, radio waves are an integral element of our daily lives but they are mostly hidden to human perception. In this paper we present SKIN, a wireless wearable system that creates a new interface between the human and WiFi signals employing sensory augmentation. SKIN translates nearby...

  16. 77 FR 27097 - LaCrosse Boiling Water Reactor, Exemption From Certain Requirements, Vernon County, WI

    Science.gov (United States)

    2012-05-08

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION LaCrosse Boiling Water Reactor, Exemption From Certain Requirements, Vernon County, WI AGENCY...) 73.55, for the LaCrosse Boiling Water Reactor (LACBWR). This Environmental Assessment (EA) has been...

  17. WiFiSiM: An Educational Tool for the Study and Design of Wireless Networks

    Science.gov (United States)

    Mateo Sanguino, T. J.; Serrano Lopez, C.; Marquez Hernandez, F. A.

    2013-01-01

    A new educational simulation tool designed for the generic study of wireless networks, the Wireless Fidelity Simulator (WiFiSim), is presented in this paper. The goal of this work was to create and implement a didactic tool to improve the teaching and learning of computer networks by means of two complementary strategies: simulating the behavior…

  18. A novel particle filter approach for indoor positioning by fusing WiFi and inertial sensors

    Directory of Open Access Journals (Sweden)

    Zhu Nan

    2015-12-01

    Full Text Available WiFi fingerprinting is the method of recording WiFi signal strength from access points (AP along with the positions at which they were recorded, and later matching those to new measurements for indoor positioning. Inertial positioning utilizes the accelerometer and gyroscopes for pedestrian positioning. However, both methods have their limitations, such as the WiFi fluctuations and the accumulative error of inertial sensors. Usually, the filtering method is used for integrating the two approaches to achieve better location accuracy. In the real environments, especially in the indoor field, the APs could be sparse and short range. To overcome the limitations, a novel particle filter approach based on Rao Blackwellized particle filter (RBPF is presented in this paper. The indoor environment is divided into several local maps, which are assumed to be independent of each other. The local areas are estimated by the local particle filter, whereas the global areas are combined by the global particle filter. The algorithm has been investigated by real field trials using a WiFi tablet on hand with an inertial sensor on foot. It could be concluded that the proposed method reduces the complexity of the positioning algorithm obviously, as well as offers a significant improvement in position accuracy compared to other conventional algorithms, allowing indoor positioning error below 1.2 m.

  19. Throughput Gain Using Threshold-Based Multiuser Scheduling in WiMAX OFDMA

    Directory of Open Access Journals (Sweden)

    Sulyman AhmedIyanda

    2011-01-01

    Full Text Available This paper presents the analysis of the throughput enhancement possible using threshold-based multiuser scheduling in WiMAX OFDMA. We consider a point-to-multipoint (PMP WiMAX network where base station (BS schedules downlink packets for simultaneous transmissions to multiple users using the WiMAX OFDMA system. WiMAX OFDMA standard specifies several subcarrier permutation options, such as the partial usage of subcarriers (PUSC, full usage of subcarrier (FUSC, and the band adaptive modulation and coding (band-AMC among others, for mapping the physical subcarriers into logical subchannels assigned to users by the BS schedulers. In this paper, we propose the use of threshold testing prior to the process of subchannel assignment to users by the BS scheduler, as a means of throughput enhancement. In the proposed threshold-based multiuser scheduling scheme, the BS scheduler selects at any time instant users whose channel gains in the available subchannels equal or exceed a predetermined energy threshold. Thus, only users who can maximize BS throughput on the available subchannels are assigned data transmission opportunities which enhance the BS data rate, albeit at the expense of fairness to users. We quantify the throughput enhancement of the proposed system and illustrate its benefits by numerical simulations.

  20. WiFi Data Acquisition System Applied to a Photovoltaic Powered Water Pumping Plant

    Directory of Open Access Journals (Sweden)

    Sandro César Silveira JUCÁ

    2015-02-01

    Full Text Available The present paper describes how to design and assemble a low cost online monitoring and WiFi data acquisition system using free software applied to microgeneration based on renewable energy sources. The development of online monitoring systems for microgeneration plants based on renewable energy sources is becoming more important, considering that monitoring and data acquisition systems are applicable in stages of the microgeneration process. The monitoring and data acquisition WiFi system was developed using an embedded WiFi modem (Wifly coupled to a microcontrolled board based on the free tool SanUSB. This monitoring system was applied to a photovoltaic (PV water pumping plant without batteries, so as the control system and the wireless communication with the online server, which is also autonomous and powered by PV panel. The free software for online monitoring and WiFi data acquisition allows the analysis of stored data and charts through mobile devices as notebooks, tablets and smartphones.

  1. Device-Free Passive Identity Identification via WiFi Signals

    Directory of Open Access Journals (Sweden)

    Jiguang Lv

    2017-11-01

    Full Text Available Device-free passive identity identification attracts much attention in recent years, and it is a representative application in sensorless sensing. It can be used in many applications such as intrusion detection and smart building. Previous studies show the sensing potential of WiFi signals in a device-free passive manner. It is confirmed that human’s gait is unique from each other similar to fingerprint and iris. However, the identification accuracy of existing approaches is not satisfactory in practice. In this paper, we present Wii, a device-free WiFi-based Identity Identification approach utilizing human’s gait based on Channel State Information (CSI of WiFi signals. Principle Component Analysis (PCA and low pass filter are applied to remove the noises in the signals. We then extract several entities’ gait features from both time and frequency domain, and select the most effective features according to information gain. Based on these features, Wii realizes stranger recognition through Gaussian Mixture Model (GMM and identity identification through a Support Vector Machine (SVM with Radial Basis Function (RBF kernel. It is implemented using commercial WiFi devices and evaluated on a dataset with more than 1500 gait instances collected from eight subjects walking in a room. The results indicate that Wii can effectively recognize strangers and can achieves high identification accuracy with low computational cost. As a result, Wii has the potential to work in typical home security systems.

  2. 78 FR 48900 - Notice of Inventory Completion: State Historical Society of Wisconsin, Madison, WI

    Science.gov (United States)

    2013-08-12

    .... 3003, of the completion of an inventory of human remains under the control of the State Historical....R50000] Notice of Inventory Completion: State Historical Society of Wisconsin, Madison, WI AGENCY... Wisconsin has completed an inventory of human remains, in consultation with the appropriate Indian tribes or...

  3. 76 FR 50172 - Designation of New Grantee, Foreign-Trade Zone 41, Milwaukee, WI

    Science.gov (United States)

    2011-08-12

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1778] Designation of New Grantee, Foreign-Trade Zone 41, Milwaukee, WI Pursuant to its authority under the Foreign-Trade Zones Act of June 18, 1934, as amended (19 U.S.C. 81a-81u), and the Foreign-Trade Zones Board Regulations (15 CFR part...

  4. 75 FR 51757 - Foreign-Trade Zone 167-Green Bay, WI; Site Renumbering Notice

    Science.gov (United States)

    2010-08-23

    ... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 167--Green Bay, WI; Site Renumbering Notice Foreign-Trade Zone 167 was approved by the FTZ Board on August 23, 1990 (Board Order 483... Elizabeth Whiteman at [email protected]trade.gov or (202) 482-0473. Dated: August 17, 2010. Andrew...

  5. WiN Argentina: Re Launch of National Chapter and New Activities

    International Nuclear Information System (INIS)

    Sayan, J.; Gervasoni, J.; Cantargi, F.; Cintas, A.; Garea, V.

    2015-01-01

    Women of the Argentinian Nuclear Sector have shared WiN Global’s vision since its birth in 1992. Many have become active members and participated in its Annual Conferences, by presenting papers or country reports (Sweden, 1995 and Russia 1996, Taiwan 1998). Due to several drastic changes in the Sector, such as projects cancellations and reduction of personnel, occurred during the late 1990’s, the National Chapter reduced its activities. Thanks to the restless work of its founder, Dr. Maela Viirsoo, and a group of new Members, the Chapter has been recently re-launched at the 40th Annual Meeting of the Argentinian Nuclear Technology Association (AATN) and new adherents have represented the country in last year’s WiN Global Annual Conference held in Australia. In this presentation, we will show our new membership and governing structure in order to fulfill the WiN Charter’s obligations and WiN Global “Rules and Procedures”. We will also present the planned activities to promote the benefits of nuclear technologies from women’s perspective. Professional women working in several nuclear fields, such as: science and technology, health, cultural, educational and social will improve the community perception towards nuclear technology by organizing lectures, exchanging ideas and stimulating joint initiatives in the educational local system. (author)

  6. OPTIMASI POSISI PILOT MENGGUNAKAN ALGORITMA GENETIKA UNTUK MENINGKATKAN KINERJA Wi-Fi 802.11n

    Directory of Open Access Journals (Sweden)

    Wahyul Amien Syafei

    2013-12-01

    Full Text Available Wi-Fi is wireless communication technology that  used widely not only for accessing the internet but also communicating data, image, voice and video. The newest wi-fi technology is 802.11n as an extention of 802.11a/b/g. By  combining OFDM and MIMO techniques it can provide throughput up to 600Mbps. One of important factors to achieve such high throughput is the pilot position in training sequence. Wi-fi802.11n allocates it’s pilots orthogonally. This research optimizes the pilot location using Genetic Algorithm Differential Evolution. Optimum pilot position improves the accuracy of synchronization which leads to enhance the performance. The invented optimum pilot position set then be implemented into wi-fi 802.11n simulator to be analyzed the performance enhancement which represented in grafic BER vs SNR curve.Run test under channel model B and D proof that the invented optimum pilot position gives performance enhancement of 0,5 dB and maintain it’s stability compared towi-fi 802.11n system with  set ortogonal pilot position.

  7. Computer Simulation and Field Experiment for Downlink Multiuser MIMO in Mobile WiMAX System.

    Science.gov (United States)

    Yamaguchi, Kazuhiro; Nagahashi, Takaharu; Akiyama, Takuya; Matsue, Hideaki; Uekado, Kunio; Namera, Takakazu; Fukui, Hiroshi; Nanamatsu, Satoshi

    2015-01-01

    The transmission performance for a downlink mobile WiMAX system with multiuser multiple-input multiple-output (MU-MIMO) systems in a computer simulation and field experiment is described. In computer simulation, a MU-MIMO transmission system can be realized by using the block diagonalization (BD) algorithm, and each user can receive signals without any signal interference from other users. The bit error rate (BER) performance and channel capacity in accordance with modulation schemes and the number of streams were simulated in a spatially correlated multipath fading environment. Furthermore, we propose a method for evaluating the transmission performance for this downlink mobile WiMAX system in this environment by using the computer simulation. In the field experiment, the received power and downlink throughput in the UDP layer were measured on an experimental mobile WiMAX system developed in Azumino City in Japan. In comparison with the simulated and experimented results, the measured maximum throughput performance in the downlink had almost the same performance as the simulated throughput. It was confirmed that the experimental mobile WiMAX system for MU-MIMO transmission successfully increased the total channel capacity of the system.

  8. 78 FR 19158 - Safety Zone; USA Triathlon, Milwaukee Harbor, Milwaukee, WI

    Science.gov (United States)

    2013-03-29

    ...-AA00 Safety Zone; USA Triathlon, Milwaukee Harbor, Milwaukee, WI AGENCY: Coast Guard, DHS. ACTION... (adjusted for inflation) or more in any one year. Though this proposed rule would not result in such... Delegation No. 0170.1. 2. Add Sec. 165.T09-0140 to read as follows: Sec. 165.T09-0140 Safety Zone; USA...

  9. 78 FR 31415 - Safety Zone; USA Triathlon; Milwaukee Harbor, Milwaukee, WI

    Science.gov (United States)

    2013-05-24

    ...-AA00 Safety Zone; USA Triathlon; Milwaukee Harbor, Milwaukee, WI AGENCY: Coast Guard, DHS. ACTION... (adjusted for inflation) or more in any one year. Though this rule would not result in such an expenditure.... Add Sec. 165.T09-0140 to read as follows: Sec. 165.T09-0140 Safety Zone; USA Triathlon, Milwaukee...

  10. TCP Performance over Wi-Fi: Joint Impact of Buffer and Channel Losses

    NARCIS (Netherlands)

    Pokhrel, S.R.; Panda, M.; Vu, H.L.; Mandjes, M.

    2016-01-01

    We propose an analytical model for a Wi-Fi network acting as a last-mile Internet access with multiple long-lived TCP connections on both the up and down links. Our model considers the joint impact of buffer losses at the access point, contention at the medium access control layer, and packet losses

  11. An investigation of scalable anomaly detection techniques for a large network of Wi-Fi hotspots

    CSIR Research Space (South Africa)

    Machaka, P

    2015-01-01

    Full Text Available . The Neural Networks, Bayesian Networks and Artificial Immune Systems were used for this experiment. Using a set of data extracted from a live network of Wi-Fi hotspots managed by an ISP; we integrated algorithms into a data collection system to detect...

  12. Experimental evaluation of high speed impulse radio UWB interference on WiMAX narrowband systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Yin, Xiaoli; Tafur Monroy, Idelfonso

    2010-01-01

    Interference of high speed impulse radio ultrawideband (IR-UWB) on 5.735GHz single carrier 64/256-QAM WiMAX narrowband signals is experimentally investigated. The experimental results indicate that the coexistence of 625Mbps and 2Gbps IR-UWB signals causes penalties of 3dB and 0.5dB respectively ...... to the WiMAX channel. At higher bit rates, IR-UWB technology is therefore expected to reduce its interference on WiMAX signals. This work serves as further motivation for the exploration of IR-UWB systems with higher speed and higher capacity.......Interference of high speed impulse radio ultrawideband (IR-UWB) on 5.735GHz single carrier 64/256-QAM WiMAX narrowband signals is experimentally investigated. The experimental results indicate that the coexistence of 625Mbps and 2Gbps IR-UWB signals causes penalties of 3dB and 0.5dB respectively...

  13. Chlorophyll-a, Orbview-2 SeaWiFS, 0.1 degrees, Global

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA GSFC Ocean Color Web distributes science-quality chlorophyll-a concentration data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the Orbview-2...

  14. Design and development of plasma antenna for wi-fi application | Ja ...

    African Journals Online (AJOL)

    In this work the commercial fluorescent lamp was chosen because it was low cost to produce plasma element. The plasma antenna in this research was made from fluorescent lamp that functioned as a radiating element with target frequency at 2.4 GHz for Wi-Fi application. The commercial fluorescent lamp consisted of ...

  15. A Wi-Fi Union Mechanism for Internet Advertising Reciprocal Platform in Microenterprises

    Directory of Open Access Journals (Sweden)

    Thi Thanh An Nguyen

    2017-07-01

    Full Text Available With the evolution of the Internet and smartphone devices, Internet advertising has become one of the most important methods for delivering promotional marketing messages to customers. However, the efficiency of Internet advertising for microenterprise is not very high, since Wi-Fi advertising—which is limited by a small router coverage area—is mainly used. Moreover, because of the lack of money, microenterprises have been using low-cost methods to promote their products. Thus, enhancing the effectiveness of Wi-Fi advertising, and solving the problem of cost and the range of the views are now an essential investigation in this study. In this paper, we propose a reciprocal model with Wi-Fi union mechanism for Internet advertising based on fog computing architecture to enhance the efficiency of advertisement, reduce the cost, and increase the range of the views for microenterprise by using the Internet. In particular, the system was built in advertisers’, publishers’, and consumers’ sides. In our system, we use contribution point (CP as an exchange value among the participants. Advertisers and publishers can get CP by helping the others in the system to promote their advertisements, increasing their CP by one unit. Similarly, advertisers and publishers can use their CP to ask for assistance from the others, decreasing their CP by one unit. The result shows that the system in a Wi-Fi union is easy to use, and advertisements can be seen by all customers who are using free Wi-Fi from the stores of the union. This method can solve the problem of cost and fixed consumer groups.

  16. Fusion of Location Fingerprinting and Trilateration Based on the Example of Differential Wi-Fi Positioning

    Science.gov (United States)

    Retscher, G.

    2017-09-01

    Positioning of mobile users in indoor environments with Wireless Fidelity (Wi-Fi) has become very popular whereby location fingerprinting and trilateration are the most commonly employed methods. In both the received signal strength (RSS) of the surrounding access points (APs) are scanned and used to estimate the user's position. Within the scope of this study the advantageous qualities of both methods are identified and selected to benefit their combination. By a fusion of these technologies a higher performance for Wi-Fi positioning is achievable. For that purpose, a novel approach based on the well-known Differential GPS (DGPS) principle of operation is developed and applied. This approach for user localization and tracking is termed Differential Wi-Fi (DWi-Fi) by analogy with DGPS. From reference stations deployed in the area of interest differential measurement corrections are derived and applied at the mobile user side. Hence, range or coordinate corrections can be estimated from a network of reference station observations as it is done in common CORS GNSS networks. A low-cost realization with Raspberry Pi units is employed for these reference stations. These units serve at the same time as APs broadcasting Wi-Fi signals as well as reference stations scanning the receivable Wi-Fi signals of the surrounding APs. As the RSS measurements are carried out continuously at the reference stations dynamically changing maps of RSS distributions, so-called radio maps, are derived. Similar as in location fingerprinting this radio maps represent the RSS fingerprints at certain locations. From the areal modelling of the correction parameters in combination with the dynamically updated radio maps the location of the user can be estimated in real-time. The novel approach is presented and its performance demonstrated in this paper.

  17. Queuing Time Prediction Using WiFi Positioning Data in an Indoor Scenario.

    Science.gov (United States)

    Shu, Hua; Song, Ci; Pei, Tao; Xu, Lianming; Ou, Yang; Zhang, Libin; Li, Tao

    2016-11-22

    Queuing is common in urban public places. Automatically monitoring and predicting queuing time can not only help individuals to reduce their wait time and alleviate anxiety but also help managers to allocate resources more efficiently and enhance their ability to address emergencies. This paper proposes a novel method to estimate and predict queuing time in indoor environments based on WiFi positioning data. First, we use a series of parameters to identify the trajectories that can be used as representatives of queuing time. Next, we divide the day into equal time slices and estimate individuals' average queuing time during specific time slices. Finally, we build a nonstandard autoregressive (NAR) model trained using the previous day's WiFi estimation results and actual queuing time to predict the queuing time in the upcoming time slice. A case study comparing two other time series analysis models shows that the NAR model has better precision. Random topological errors caused by the drift phenomenon of WiFi positioning technology (locations determined by a WiFi positioning system may drift accidently) and systematic topological errors caused by the positioning system are the main factors that affect the estimation precision. Therefore, we optimize the deployment strategy during the positioning system deployment phase and propose a drift ratio parameter pertaining to the trajectory screening phase to alleviate the impact of topological errors and improve estimates. The WiFi positioning data from an eight-day case study conducted at the T3-C entrance of Beijing Capital International Airport show that the mean absolute estimation error is 147 s, which is approximately 26.92% of the actual queuing time. For predictions using the NAR model, the proportion is approximately 27.49%. The theoretical predictions and the empirical case study indicate that the NAR model is an effective method to estimate and predict queuing time in indoor public areas.

  18. A Wi-Fi Union Mechanism for Internet Advertising Reciprocal Platform in Microenterprises.

    Science.gov (United States)

    Nguyen, Thi Thanh An; Chang, Che-Pin; Yuan, Shyan-Ming

    2017-07-13

    With the evolution of the Internet and smartphone devices, Internet advertising has become one of the most important methods for delivering promotional marketing messages to customers. However, the efficiency of Internet advertising for microenterprise is not very high, since Wi-Fi advertising-which is limited by a small router coverage area-is mainly used. Moreover, because of the lack of money, microenterprises have been using low-cost methods to promote their products. Thus, enhancing the effectiveness of Wi-Fi advertising, and solving the problem of cost and the range of the views are now an essential investigation in this study. In this paper, we propose a reciprocal model with Wi-Fi union mechanism for Internet advertising based on fog computing architecture to enhance the efficiency of advertisement, reduce the cost, and increase the range of the views for microenterprise by using the Internet. In particular, the system was built in advertisers', publishers', and consumers' sides. In our system, we use contribution point (CP) as an exchange value among the participants. Advertisers and publishers can get CP by helping the others in the system to promote their advertisements, increasing their CP by one unit. Similarly, advertisers and publishers can use their CP to ask for assistance from the others, decreasing their CP by one unit. The result shows that the system in a Wi-Fi union is easy to use, and advertisements can be seen by all customers who are using free Wi-Fi from the stores of the union. This method can solve the problem of cost and fixed consumer groups.

  19. Functional significance of protein assemblies predicted by the crystal structure of the restriction endonuclease BsaWI.

    Science.gov (United States)

    Tamulaitis, Gintautas; Rutkauskas, Marius; Zaremba, Mindaugas; Grazulis, Saulius; Tamulaitiene, Giedre; Siksnys, Virginijus

    2015-09-18

    Type II restriction endonuclease BsaWI recognizes a degenerated sequence 5'-W/CCGGW-3' (W stands for A or T, '/' denotes the cleavage site). It belongs to a large family of restriction enzymes that contain a conserved CCGG tetranucleotide in their target sites. These enzymes are arranged as dimers or tetramers, and require binding of one, two or three DNA targets for their optimal catalytic activity. Here, we present a crystal structure and biochemical characterization of the restriction endonuclease BsaWI. BsaWI is arranged as an 'open' configuration dimer and binds a single DNA copy through a minor groove contacts. In the crystal primary BsaWI dimers form an indefinite linear chain via the C-terminal domain contacts implying possible higher order aggregates. We show that in solution BsaWI protein exists in a dimer-tetramer-oligomer equilibrium, but in the presence of specific DNA forms a tetramer bound to two target sites. Site-directed mutagenesis and kinetic experiments show that BsaWI is active as a tetramer and requires two target sites for optimal activity. We propose BsaWI mechanism that shares common features both with dimeric Ecl18kI/SgrAI and bona fide tetrameric NgoMIV/SfiI enzymes. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. SeaWiFS technical report series. Volume 26: Results of the SeaWiFS Data Analysis Round-Robin, July 1994 (DARR-1994)

    Science.gov (United States)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Siegel, David A.; Obrien, Margaret C.; Sorensen, Jen C.; Konnoff, Daniel A.; Brody, Eric A.; Mueller, James L.; Davis, Curtiss O.; Rhea, W. Joseph

    1995-01-01

    The accurate determination of upper ocean apparent optical properties (AOP's) is essential for the vicarious calibration of the sea-viewing wide field-of-view sensor (SeaWiFS) instrument and the validation of the derived data products. To evaluate the role that data analysis methods have upon values of derived AOP's, the first Data Analysis Round-Robin (DARR-94) workshop was sponsored by the SeaWiFS Project during 21-23 July, 1994. The focus of this intercomparison study was the estimation of the downwelling irradiance spectrum just beneath the sea surface, E(sub d)(0(sup -), lambda); the upwelling nadir radiance just beneath the sea surface, L(sub u)(0(sup -), lambda); and the vertical profile of the diffuse attenuation coefficient spectrum, K(sub d)(z, lambda). In the results reported here, different methodologies from four research groups were applied to an identical set of 10 spectroradiometry casts in order to evaluate the degree to which data analysis methods influence AOP estimation, and whether any general improvements can be made. The overall results of DARR-94 are presented in Chapter 1 and the individual methods of the four groups are presented in Chapters 2-5. The DARR-94 results do not show a clear winner among data analysis methods evaluated. It is apparent, however, that some degree of outlier rejection is required in order to accurately estimate L(sub u)(0(sup -), lambda) or E(sub d)(0(sup -), lambda). Furthermore, the calculation, evaluation and exploitation of confidence intervals for the AOP determinations needs to be explored. That is, the SeaWiFS calibration and validation problem should be recast in statistical terms where the in situ AOP values are statistical estimates with known confidence intervals.

  1. Service Level Agreement for the QoS Guaranteed Mobile IPTV Services over Mobile WiMAX Networks

    OpenAIRE

    Chowdhury, Mostafa Zaman; Trung, Bui Minh; Jang, Yeong Min; Kim, Young-Il; Ryu, Won

    2011-01-01

    While mobile IPTV services are supported through the mobile WiMAX networks, there must need some guaranteed bandwidth for the IPTV services especially if IPTV and non-IPTV services are simultaneously supported by the mobile WiMAX networks. The quality of an IPTV service definitely depends on the allocated bandwidth for that channel. However, due to the high quality IPTV services and to support of huge non-IPTV traffic over mobile WiMAX networks, it is not possible to guarantee the sufficient ...

  2. Portal Website Analysis Using ISO / IEC 9126-4 Metric Effectiveness (Case Study Indonesia Wi-Fi Portal Website)

    OpenAIRE

    Jumrotuhuda, Refky

    2014-01-01

    According to the increasing of human necessity, Development of technology have to bring the same increasing in order to support and facilitate every activity in all sorts of the human life. Internet is the one of the real outcome from the development of technology. Indonesia Wi-Fi is a public internet network server based on Wi-Fi/Hotspot technology developed by TELKOM Group and other related operator to the TELKOM enterprise. Portal website of Indonesia Wi-Fi is used as a portal for user to ...

  3. Wifi, WiMax and LTE multi-hop mesh networks basic communication protocols and application areas

    CERN Document Server

    Wei, Hung-Yu; Dixit, Sudhir

    2013-01-01

    Wifi, WiMAX, and Cellular Multihop Networks presents an overview of WiFi-based and WiMAX-based multihop relay networks. As the first text to cover IEEE 802.16j multihop hop relay technology, this revolutionary resource explores the latest advances in multi-hop and ad-hoc networking. Not only does this reference provide the technological aspects, but also the applications for the emerging technology and architectural issues. Ranging from introductory material to advanced topics, this guidebook, plus PowerPoint slides, is essential for engineers, researchers, and students interested in

  4. Effects of electromagnetic waves emitted from 3G+wi-fi modems on human semen analysis.

    Science.gov (United States)

    Kamali, Koosha; Atarod, Mohammadmehdi; Sarhadi, Saeedeh; Nikbakht, Javad; Emami, Maryam; Maghsoudi, Robab; Salimi, Hormoz; Fallahpour, Bita; Kamali, Negar; Momtazan, Abdolreza; Ameli, Mojtaba

    2017-10-25

    The purpose of this study was to evaluate the effects of 3G+wifi modems on human sperm quality.A total of 40 semen specimens were gathered between March and September 2015, from healthy adult men. The sperm samples were divided into two groups - 3G+wi-fi exposed and unexposed groups. In the unexposed group, the specimens were shielded by aluminum foil in three layers and put into an incubator at a temperature of 37°C for 50 minutes. The exposed group was positioned in another room in an incubator at a temperature of 37°C for 50 minutes. A 3G+wi-fi modem was put into the same incubator and a laptop computer was connected to the modem and was downloading for the entire 50 minutes.Semen analysis was done for each specimen and comparisons between parameters of the two groups were done by using Kolmogorov-Smirnov study and a paired t-test. Mean percentage of sperm with class A and B motility were not significantly different in two groups (p = 0.22 and 0.54, respectively). In class C, it was significantly lower in the exposed group (p = 0.046), while in class D it was significantly higher (p = 0.022).Velocity curvilinear, velocity straight line, velocity average path, mean angular displacement, lateral displacement and beat cross frequency were significantly higher in the unexposed group. The limitation was the in vitro design. Electromagnetic waves (EMWs) emitted from 3G+wi-fi modems cause a significant decrease in sperm motility and velocity, especially in non-progressive motile sperms. Other parameters of semen analysis did not change significantly.EMWs, which are used in communications worldwide, are a suspected cause of male infertility. Many studies evaluated the effects of cell phones and wi-fi on fertility. To our knowledge, no study has yet been done to show the effects of EMWs emitted from 3G+wi-fi modems on fertility.Our study revealed a significant decrease in the quality of human semen after exposure to EMWs emitted from 3G+wi-fi modems.

  5. Analisis Kinerja Subscriber Station WiMAX di Urban Area Bandung

    Directory of Open Access Journals (Sweden)

    DWI ARYANTA

    2017-06-01

    Full Text Available ABSTRAK   Teknologi komunikasi wireless semakin pesat mengalami perkembangan. WiMAX  merupakan suatu teknologi broadband yang didukung oleh standar IEEE 802.16d (802.16-2004 yang mampu memberikan layanan data berkecepatan tinggi hingga 75 Mbps dalam radius maksimal 40-50 km pada bandwidth 20 MHz. Alokasi frekuensi yang dipakai Indonesia untuk jaringan WiMAX  ini ialah 3,3 – 3,4 GHz. Penelitian ini dilakukan dengan melakukan proses pengukuran kinerja perangkat radio WiMAX  yaitu HiMax 331-SS. Proses pengukuran dilakukan antara CPE dan base station dengan antenna sektoral 1200 pada ketinggian 45 m. Lokasi pengukuran dilakukan di beberapa area kota Bandung yang telah ditentukan sebelumnya. Hasil pengukuran memperlihatkan nilai CINR tertinggi adalah 31 dB dengan modulasi 64 QAM – ¾ dan terendah nilai 10 dB dengan modulasi BPSK 1/2. Nilai RSSI tertinggi -54 dBm berada dan nilai RSSI terendah -89 dBm. Nilai throughput tertinggi untuk layanan streaming video sebesar  1000,8 kbps (downlink dengan modulasi 64 QAM – ¾. Nilai delay terendah sebesar 56,247 ms pada kondisi LOS dan tertinggi sebesar 139,5 ms pada kondisi NLOS. Nilai terbesar packet loss sebesar 20% yaitu pada lokasi pengukuran terjauh 14,3 km. Kata Kunci : delay, packet loss, RSSI, CINR, throughput, CPE, WiMAX .   ABSTRACT   Wireless communication technologies have evolved more rapidly. WiMAX  is a broadband technology that is supported by the IEEE standard 802.16-2004/d which is able to provide high speed data services of up to 75 Mbps within a radius of 40-50 km at a maximum bandwidth of 20 MHz. Indonesia frequency allocation used for the WiMAX  network is 3.3 to 3.4 GHz. This study was conducted with the performance measurement process that is Himax 331 WiMAX  radio - SS. Process measurement is made between the CPE and base station sector antennas at a height of 45 m in 1200. Locations measurements performed in several areas of Bandung predetermined. The measurement

  6. Positioning indoors with Wi-Fi devices of low-cost

    International Nuclear Information System (INIS)

    Moreira, Fabricio M.; Farias, Marcos S.; Carvalho, Paulo Victor R. de

    2017-01-01

    The rhythm of research development linked to location tracking is highly linked with the advancement of wireless sensor network and wireless technologies. A classic example is the Global Positioning System (GPS), where satellites are used to send signals to receivers on earth that use these signals to compute navigation information. However, as communication between the satellites and GPS receivers require radio propagation in line of sight, the GPS system usually only works outdoors. For the growing interest in research to position tracking indoors, you must use wireless devices based on Bluetooth or Wi-Fi technology (IEEE 802.11). The aim of this work is to show the development of applications using new Wi-Fi devices (ESP8266) for the estimation of positioning and location indoors

  7. A Wireless Physiological Signal Monitoring System with Integrated Bluetooth and WiFi Technologies.

    Science.gov (United States)

    Yu, Sung-Nien; Cheng, Jen-Chieh

    2005-01-01

    This paper proposes a wireless patient monitoring system which integrates Bluetooth and WiFi wireless technologies. A wireless portable multi-parameter device was designated to acquire physiological signals and transmit them to a local server via Bluetooth wireless technology. Four kinds of monitor units were designed to communicate via the WiFi wireless technology, including a local monitor unit, a control center, mobile devices (personal digital assistant; PDA), and a web page. The use of various monitor units is intending to meet different medical requirements for different medical personnel. This system was demonstrated to promote the mobility and flexibility for both the patients and the medical personnel, which further improves the quality of health care.

  8. Capacity Evaluation for IEEE 802.16e Mobile WiMAX

    Directory of Open Access Journals (Sweden)

    Chakchai So-In

    2010-01-01

    Full Text Available We present a simple analytical method for capacity evaluation of IEEE 802.16e Mobile WiMAX networks. Various overheads that impact the capacity are explained and methods to reduce these overheads are also presented. The advantage of a simple model is that the effect of each decision and sensitivity to various parameters can be seen easily. We illustrate the model by estimating the capacity for three sample applications—Mobile TV, VoIP, and data. The analysis process helps explain various features of IEEE 802.16e Mobile WiMAX. It is shown that proper use of overhead reducing mechanisms and proper scheduling can make an order of magnitude difference in performance. This capacity evaluation method can also be used for validation of simulation models.

  9. Experience of the WiN Hungary in Communication with Public on a Big Social Events

    International Nuclear Information System (INIS)

    Szucsán, M.

    2015-01-01

    My poster presentation is about a process of communication with public during big social events like festivals, open days and sport’s competitions. The technique is: we make a WiN stand on the frequent place of events, invite visitors and kindly ask them to fill our questionnaire about nuclear industry in Hungary. The questionnaire contents 15 questions about Hungarian NPP (how many units we have, what is electrical output). We communicate with visitors during the filling a questionnaire and after that we check the result. We can see the level of knowledge of our guest and give them the appropriate information on their level. Usually every participant takes a small present with the emblem of WiN Hungary. This form of communication has tested many times in our activity. It works very effectively. The form of poster is a chart flow of the process illustrated with photos. (author)

  10. A WiMAX Networked UAV Telemetry System for Net-Centric Remote Sensing and Range Surveillance, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A WiMAX networked UAV Telemetry System (WNUTS) is designed for net-centric remote sensing and launch range surveillance applications. WNUTS integrates a MIMO powered...

  11. Implementació de càmera Wi-Fi mitjançant dispositiu mòbil

    OpenAIRE

    Simon Bisbal, Jordi Tabaré

    2012-01-01

    Implementació de càmera IP per Wi-Fi mitjançant dispositiu mòbil. [ANGLÈS] IP Camera implementation with Android SDK. It takes the images from the device cam and sends them through the Wi-Fi network using RTP. [CASTELLÀ] Implementación en Android SDK de cámara IP, que envía las imágenes captadas por el móvil a través de la red Wi-Fi mediante RTP. [CATALÀ] Implementació en Android SDK de càmera IP, que envia les imatges captades pel la càmera del mòbil en RTP a través de la xarxa Wi-F...

  12. The Role of the WI-38 Cell Strain in Saving Lives and Reducing Morbidity

    OpenAIRE

    S. J. Olshansky; L. Hayflick

    2017-01-01

    The modern success story of vaccinations involves a historical chain of events that transformed the discovery that vaccines worked, to administering them to the population. We estimate the number of lives saved and morbidity reduction associated with the discovery of the first human cell strain used for the production of licensed human virus vaccines, known as WI-38. The diseases studied include poliomyelitis, measles, mumps, rubella, varicella (chicken pox), herpes zoster, adenovirus, rabies...

  13. WiFi Hot Spot Service Business for the Automotive and Oil Industries: A Competitive Analysis

    Directory of Open Access Journals (Sweden)

    Louis-Francois PAU

    2010-01-01

    Full Text Available While you refuel for gas, why not refuel for information or upload vehicle data, using a cheap wireless technology as WiFi? This paper analyzes in extensive detail the user segmentation by vehicle usage, service offering, and full business models from WiFi hot spot services delivered to and from vehicles (private, professional, public around gas stations. Are also analyzed the parties which play a role in such services: authorization, provisioning and delivery, with all the dependencies modelled by attributed digraphs. Account is made of WiFi base station technical capabilities and costs. Five year financial models (CAPEX, OPEX, and data pertain to two possible service suppliers: multi-service oil companies, and mobile service operators (or MVNOs. Model optimization on the return-on-investment (R.O.I. is carried out for different deployment scenarios, geographical coverage assumptions, as well as tariff structures. Comparison is also being made with public GPRS and 3G data services, as precursors to HSPA/LTE, and the effect of WiFi roaming is analyzed. Regulatory implications, including those dealing with public safety, are addressed. Analysis shows that due to manpower costs and marketing costs, suitable R.O.I. will not be achieved unless externalities are accounted for and innovative tariff structures are introduced. Open issues and further research are outlined. Further work is currently carried out with automotive electronics sector, wireless systems providers, wireless terminals platform suppliers, and vehicle manufacturers. Future relevance of this work is also discussed for the emerging electrical reloading grids for electrical vehicles.

  14. Hybrid RSOA and fibre raman amplified long reach feeder link for WiMAX-on-fibre

    DEFF Research Database (Denmark)

    Amaya Fernández, Ferney Orlando; Martinez, Javier; Yu, Xianbin

    2009-01-01

    A distributed fibre Raman amplified long reach optical access feeder link using a reflective semiconductor optical amplifier in the remote base station is experimentally demonstrated for supporting WiMAXover- fibre transmission. The measured values for the error vector magnitude for quadrature ph...... phase shift keying and 16-ary quadrature amplitude modulation after 40 km of fibre transmission meet the IEEE 820.16 standard requirements...

  15. Performance Analysis of VoIP Codecs over WiMAX Networks

    OpenAIRE

    M.A. Mohamed; F.W. Zaki; A.M. Elfeki

    2012-01-01

    Real-time services such as VoIP are becoming popular and are major revenue earners for network service providers. These services no longer confined to the wired domain and extended over wireless networks. Although some of the existing wireless technologies can support some low-band width applications, the bandwidth demands of many multimedia applications exceed the capacity of these technologies. The WiMAX promises to be one of the wireless access technologies capable of supporting very high ...

  16. A Wi-Fi Union Mechanism for Internet Advertising Reciprocal Platform in Microenterprises

    OpenAIRE

    Thi Thanh An Nguyen; Che-Pin Chang; Shyan-Ming Yuan

    2017-01-01

    With the evolution of the Internet and smartphone devices, Internet advertising has become one of the most important methods for delivering promotional marketing messages to customers. However, the efficiency of Internet advertising for microenterprise is not very high, since Wi-Fi advertising?which is limited by a small router coverage area?is mainly used. Moreover, because of the lack of money, microenterprises have been using low-cost methods to promote their products. Thus, enhancing the ...

  17. RF Exposure Analysis for Multiple Wi-Fi Devices In Enclosed Environment

    Science.gov (United States)

    Hwu, Shian U.; Rhodes, Bryan A.; deSilva, B. Kanishka; Sham, Catherine C.; Keiser, James R.

    2013-01-01

    Wi-Fi devices operated inside a metallic enclosure have been investigation in the recent years. A motivation for this study is to investigate wave propagation inside an enclosed environment such as elevator, car, aircraft, and spacecraft. There are performances and safety concerned that when the RF transmitters are used in the metallic enclosed environments. In this paper, the field distributions inside a confined room were investigated with multiple portable Wi-Fi devices. Computer simulations were performed using the rigorous computational electromagnetics (CEM). The method of moments (MoM) was used to model the mutual coupling among antennas. The geometrical theory of diffraction (GTD) was applied for the multiple reflections off the ground and walls. The prediction of the field distribution inside such environment is useful for the planning and deployment of a wireless radio and sensor system. Factors that affect the field strengths and distributions of radio waves in confined space were analyzed. The results could be used to evaluate the RF exposure safety in confined environment. By comparing the field distributions for various scenarios, it was observed that the Wi-Fi device counts, spacing and relative locations in the room are important factors in such environments. The RF Keep Out Zone (KOZ), where the electric field strengths exceed the permissible RF exposure limit, could be used to assess the RF human exposure compliance. As shown in this study, it s possible to maximize or minimize field intensity in specific area by arranging the Wi-Fi devices as a function of the relative location and spacing in a calculated manner.

  18. Effect of in utero wi-fi exposure on the pre- and postnatal development of rats.

    Science.gov (United States)

    Poulletier de Gannes, Florence; Haro, Emmanuelle; Hurtier, Annabelle; Taxile, Murielle; Athane, Axel; Ait-Aissa, Saliha; Masuda, Hiroshi; Percherncier, Yann; Ruffié, Gilles; Billaudel, Bernard; Dufour, Philippe; Veyret, Bernard; Lagroye, Isabelle

    2012-04-01

    The increase in exposure to the Wireless Fidelity (Wi-Fi) wireless communication signal has raised public health concerns especially for young people. Animal studies looking at the effects of early life and prenatal exposure to this source of electromagnetic fields, in the radiofrequency (RF) range, on development and behavior have been considered as high priority research needs by the World Health Organization. For the first time, our study assessed the effects of in utero exposure to a 2450 MHz Wi-Fi signal (2 hr/day, 6 days/week for 18 days) on pregnant rats and their pups. Three levels in terms of whole-body specific absorption rate were used: 0.08, 0.4, and 4 W/kg. The prenatal study on fetuses delivered by caesarean (P20) concerned five females/group. The dams and their offspring were observed for 28 days after delivery (15 females/group). For all test conditions, no abnormalities were noted in the pregnant rats and no significant signs of toxicity were observed in the pre- and postnatal development of the pups, even at the highest level of 4 W/kg. In the present study, no teratogenic effect of repeated exposures to the Wi-Fi wireless communication signal was demonstrated even at the highest level of 4 W/kg. The results from this screening study aimed at investigating Wi-Fi effects, strengthen the previous conclusions that teratology and development studies have not detected any noxious effects of exposures to mobile telephony-related RF fields at exposure levels below standard limits. © 2012 Wiley Periodicals, Inc.

  19. Design and Development of Basic Physical Layer WiMAX Network Simulation Models

    Science.gov (United States)

    2009-01-01

    Wide Web . The third software version was developed during the period of 22 August to 4 November, 2008. The software version developed during the...researched on the Web . The mathematics of some fundamental concepts such as Fourier transforms, convolutional coding techniques were also reviewed...Mathworks Matlab users’ website. A simulation model was found, entitled Estudio y Simulacion de la capa Jisica de la norma 802.16 ( Sistema WiMAX) developed

  20. Regional to Global Assessments of Phytoplankton Dynamics From The SeaWiFS Mission

    Science.gov (United States)

    Siegel, David; Behrenfeld, Michael; Maritorena, Stephanie; McClain, Charles R.; Antoine, David; Bailey, Sean W.; Bontempi, Paula S.; Boss, Emmanuel S.; Dierssen, Heidi M.; Doney, Scott C.; hide

    2013-01-01

    Photosynthetic production of organic matter by microscopic oceanic phytoplankton fuels ocean ecosystems and contributes roughly half of the Earth's net primary production. For 13 years, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission provided the first consistent, synoptic observations of global ocean ecosystems. Changes in the surface chlorophyll concentration, the primary biological property retrieved from SeaWiFS, have traditionally been used as a metric for phytoplankton abundance and its distribution largely reflects patterns in vertical nutrient transport. On regional to global scales, chlorophyll concentrations covary with sea surface temperature (SST) because SST changes reflect light and nutrient conditions. However, the oceanmay be too complex to be well characterized using a single index such as the chlorophyll concentration. A semi-analytical bio-optical algorithm is used to help interpret regional to global SeaWiFS chlorophyll observations from using three independent, well-validated ocean color data products; the chlorophyll a concentration, absorption by CDM and particulate backscattering. First, we show that observed long-term, global-scale trends in standard chlorophyll retrievals are likely compromised by coincident changes in CDM. Second, we partition the chlorophyll signal into a component due to phytoplankton biomass changes and a component caused by physiological adjustments in intracellular chlorophyll concentrations to changes in mixed layer light levels. We show that biomass changes dominate chlorophyll signals for the high latitude seas and where persistent vertical upwelling is known to occur, while physiological processes dominate chlorophyll variability over much of the tropical and subtropical oceans. The SeaWiFS data set demonstrates complexity in the interpretation of changes in regional to global phytoplankton distributions and illustrates limitations for the assessment of phytoplankton dynamics using chlorophyll

  1. Received Signal Strength Database Interpolation by Kriging for a Wi-Fi Indoor Positioning System.

    Science.gov (United States)

    Jan, Shau-Shiun; Yeh, Shuo-Ju; Liu, Ya-Wen

    2015-08-28

    The main approach for a Wi-Fi indoor positioning system is based on the received signal strength (RSS) measurements, and the fingerprinting method is utilized to determine the user position by matching the RSS values with the pre-surveyed RSS database. To build a RSS fingerprint database is essential for an RSS based indoor positioning system, and building such a RSS fingerprint database requires lots of time and effort. As the range of the indoor environment becomes larger, labor is increased. To provide better indoor positioning services and to reduce the labor required for the establishment of the positioning system at the same time, an indoor positioning system with an appropriate spatial interpolation method is needed. In addition, the advantage of the RSS approach is that the signal strength decays as the transmission distance increases, and this signal propagation characteristic is applied to an interpolated database with the Kriging algorithm in this paper. Using the distribution of reference points (RPs) at measured points, the signal propagation model of the Wi-Fi access point (AP) in the building can be built and expressed as a function. The function, as the spatial structure of the environment, can create the RSS database quickly in different indoor environments. Thus, in this paper, a Wi-Fi indoor positioning system based on the Kriging fingerprinting method is developed. As shown in the experiment results, with a 72.2% probability, the error of the extended RSS database with Kriging is less than 3 dBm compared to the surveyed RSS database. Importantly, the positioning error of the developed Wi-Fi indoor positioning system with Kriging is reduced by 17.9% in average than that without Kriging.

  2. Monitoring and remote control of energy consumption by WiFi networks. Smart energy saving platform

    OpenAIRE

    Zarza Sánchez, Sergio; Fernández Canti, Rosa M.; Lázaro Villa, José Antonio; Ortega Gómez, Isidre; Altabas, Jose Antonio

    2014-01-01

    In this paper we present a modular system for remote monitoring and control of energy consumption. In particular, we demonstrate the application of the proposed system for electric energy monitoring and control in domestic or medium size office installations. This whole system is integrated in a single platform and consists of different modules: one or several smart plugs including a wireless communication interface for connection to a WiFi network, and a centralized application server. The d...

  3. Návrh rozšíření WiFi sítě

    OpenAIRE

    Zahradník, Tomáš

    2008-01-01

    Tato bakalářská práce se zabývá rozsáhlou WiFi sítí společnosti VIVO CONNECTION s.r.o. a návrhem jejího rozšíření. The Bachelor work deals with the project of WiFi network expansion for VIVO CONNECTION s.r.o. company. B

  4. WiMAX OFDM system simulation and sub-system FPGA implementation

    International Nuclear Information System (INIS)

    Elaskary, A.M.F.

    2009-01-01

    Orthogonal frequency division multiplexing (OFDM) has been used in many wireless communication systems also it is gaining a lot of attention for the next generations of mobile communication systems. OFDM is considered a good candidate for wireless systems because it has high bandwidth efficiency and can transmit at very high data rate in multi path, interference , and fading environment. in general OFDM has widely been studied and implemented to combat transmission channel impairments, but some challenges still facing OFDM in transmission system implementation especially for recent and future applications. One of these important applications is the worldwide interoperability for microwave access (WiMAX) system. According to the IEEE 802.16 standards, WiMAX is considered as a good solution for last mile connection at crowded areas and a high-speed internet connection to mobile vehicles with speed of up to 300 km/h. This thesis studies OFDM system in details and proposes simulink models for simulating OFDM impairments and its effects on system performance. This study has been used for building up system level and end to end WiMAX OFDM transmitter/receiver which follows published specifications in IEEE 802.16 standards using mat lab/simulink.

  5. Fair Adaptive Bandwidth and Subchannel Allocation in the WiMAX Uplink

    Directory of Open Access Journals (Sweden)

    Antoni Morell

    2009-01-01

    Full Text Available In some modern communication systems, as it is the case of WiMAX, it has been decided to implement Demand Assignment Multiple Access (DAMA solutions. End-users request transmission opportunities before accessing the system, which provides an efficient way to share system resources. In this paper, we briefly review the PHY and MAC layers of an OFDMA-based WiMAX system, and we propose to use a Network Utility Maximization (NUM framework to formulate the DAMA strategy foreseen in the uplink of IEEE 802.16. Utility functions are chosen to achieve fair solutions attaining different degrees of fairness and to further support the QoS requirements of the services in the system. Moreover, since the standard allocates resources in a terminal basis but each terminal may support several services, we develop a new decomposition technique, the coupled-decompositions method, that obtains the optimal service flow allocation with a small number of iterations (the improvement is significant when compared to other known solutions. Furthermore, since the PHY layer in mobile WiMAX has the means to adapt the transport capacities of the links between the Base Station (BS and the Subscriber Stations (SSs, the proposed PHY-MAC cross-layer design uses this extra degree of freedom in order to enhance the network utility.

  6. The Making of a Sustainable Wireless City? Mapping Public Wi-Fi Access in Shanghai

    Directory of Open Access Journals (Sweden)

    Mingfeng Wang

    2016-01-01

    Full Text Available In the context of the global information economy, ready access to the Internet is critical to a city’s competitiveness, which has prompted a number of cities to launch plans to establish wireless networks. Most literature on the development of wireless cities focuses on cities in Western countries, and few have discussed how Chinese cities have adopted wireless technologies in their urban infrastructure development efforts. This paper examines recent development and spatial distribution of public Wi-Fi access in Shanghai, a leading business hub in China. We mapped Wi-Fi hotspots through the government sponsored “i-Shanghai” project and China Mobile Communications Corporation (CMCC. We find that while telecommunication providers have been proactively deploying WLAN (wireless local area network,a proxy of public Wi-Fi or wireless access hotspots in Shanghai, neither government sponsored WLAN hotspots nor facilities established by CMCC could cover the old traditional neighborhoods in the central city and sub-districts in remote rural areas. We also address the development of a more sustainable wireless city in Shanghai with a particular focus on digital divide and social equity issues.

  7. Design of smart home gateway based on Wi-Fi and ZigBee

    Science.gov (United States)

    Li, Yang

    2018-04-01

    With the increasing demand for home lifestyle, the traditional smart home products have been unable to meet the needs of users. Aim at the complex wiring, high cost and difficult operation problems of traditional smart home system, this paper designs a home gateway for smart home system based on Wi-Fi and ZigBee. This paper first gives a smart home system architecture base on cloud server, Wi-Fi and ZigBee. This architecture enables users to access the smart home system remotely from Internet through the cloud server or through Wi-Fi at home. It also offers the flexibility and low cost of ZigBee wireless networking for home equipment. This paper analyzes the functional requirements of the home gateway, and designs a modular hardware architecture based on the RT5350 wireless gateway module and the CC2530 ZigBee coordinator module. Also designs the software of the home gateway, including the gateway master program and the ZigBee coordinator program. Finally, the smart home system and home gateway are tested in two kinds of network environments, internal network and external network. The test results show that the designed home gateway can meet the requirements, support remote and local access, support multi-user, support information security technology, and can timely report equipment status information.

  8. Fusion of WiFi, Smartphone Sensors and Landmarks Using the Kalman Filter for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Zhenghua Chen

    2015-01-01

    Full Text Available Location-based services (LBS have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m.

  9. PDR/INS/WiFi Integration Based on Handheld Devices for Indoor Pedestrian Navigation

    Directory of Open Access Journals (Sweden)

    Yuan Zhuang

    2015-06-01

    Full Text Available Providing an accurate and practical navigation solution anywhere with portable devices, such as smartphones, is still a challenge, especially in environments where global navigation satellite systems (GNSS signals are not available or are degraded. This paper proposes a new algorithm that integrates inertial navigation system (INS and pedestrian dead reckoning (PDR to combine the advantages of both mechanizations for micro-electro-mechanical systems (MEMS sensors in pedestrian navigation applications. In this PDR/INS integration algorithm, a pseudo-velocity-vector, which is composed of the PDR-derived forward speed and zero lateral and vertical speeds from non-holonomic constraints (NHC, works as an update for the INS to limit the velocity errors. To further limit the drift of MEMS inertial sensors, trilateration-based WiFi positions with small variances are also selected as updates for the PDR/INS integrated system. The experiments illustrate that positioning error is decreased by 60%–75% by using the proposed PDR/INS integrated MEMS solution when compared with PDR. The positioning error is further decreased by 15%–55% if the proposed PDR/INS/WiFi integrated solution is implemented. The average accuracy of the proposed PDR/INS/WiFi integration algorithm achieves 4.5 m in indoor environments.

  10. Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency.

    Science.gov (United States)

    Maglogiannis, Vasilis; Naudts, Dries; Shahid, Adnan; Giannoulis, Spilios; Laermans, Eric; Moerman, Ingrid

    2017-08-31

    On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner.

  11. WiFiabe: un’esperienza di storytelling dal territorio al web 2.0

    Directory of Open Access Journals (Sweden)

    Marco Carnesecchi

    2013-03-01

    Full Text Available L’impatto iniziale di WiRoni sulla popolazione di Monteroni d’Arbia (Siena è stato limitato alla fruizione dei contenuti caricati dal team di design, in particolare le storie per i bambini. Mancavano infatti brani audio prodotti dalla comunità locale. In realtà, però, la competenza tecnica necessaria a trasmettere i contenuti nel parco e in rete è minima (upload da CMS wordpress e anche le tecnologie per registrare e arricchire l’audio con effetti sonori sono alla portata di tutti, se opportunamente guidati da esperti. Da queste osservazioni è nato il progetto WiFiabe. Nel corso dell’anno scolastico 2010/2011 20 bambini tra 6 e 13 anni, coordinati da un’educatrice durante l’attività di doposcuola del Comune, hanno lavorato in gruppi e creato storie di fantasia. In seguito, alcuni studenti dell’Università di Siena, con l’aiuto di un musicista per la parte degli effetti sonori, hanno assistito i ragazzi nel diventare autori digitali e apprendere in prima persona come trasformare le loro storie in contenuti audio. In questo modo i partecipanti hanno interagito con il web non in quanto fruitori ma come autori, e messo in moto un processo per rendere WiRoni uno strumento per dare voce alle varie anime della comunità.

  12. A Map/INS/Wi-Fi Integrated System for Indoor Location-Based Service Applications.

    Science.gov (United States)

    Yu, Chunyang; Lan, Haiyu; Gu, Fuqiang; Yu, Fei; El-Sheimy, Naser

    2017-06-02

    In this research, a new Map/INS/Wi-Fi integrated system for indoor location-based service (LBS) applications based on a cascaded Particle/Kalman filter framework structure is proposed. Two-dimension indoor map information, together with measurements from an inertial measurement unit (IMU) and Received Signal Strength Indicator (RSSI) value, are integrated for estimating positioning information. The main challenge of this research is how to make effective use of various measurements that complement each other in order to obtain an accurate, continuous, and low-cost position solution without increasing the computational burden of the system. Therefore, to eliminate the cumulative drift caused by low-cost IMU sensor errors, the ubiquitous Wi-Fi signal and non-holonomic constraints are rationally used to correct the IMU-derived navigation solution through the extended Kalman Filter (EKF). Moreover, the map-aiding method and map-matching method are innovatively combined to constrain the primary Wi-Fi/IMU-derived position through an Auxiliary Value Particle Filter (AVPF). Different sources of information are incorporated through a cascaded structure EKF/AVPF filter algorithm. Indoor tests show that the proposed method can effectively reduce the accumulation of positioning errors of a stand-alone Inertial Navigation System (INS), and provide a stable, continuous and reliable indoor location service.

  13. Rat fertility and embryo fetal development: influence of exposure to the Wi-Fi signal.

    Science.gov (United States)

    Poulletier de Gannes, Florence; Billaudel, Bernard; Haro, Emmanuelle; Taxile, Murielle; Le Montagner, Laureline; Hurtier, Annabelle; Ait Aissa, Saliha; Masuda, Hiroshi; Percherancier, Yann; Ruffié, Gilles; Dufour, Philippe; Veyret, Bernard; Lagroye, Isabelle

    2013-04-01

    In recent decades, concern has been growing about decreasing fecundity and fertility in the human population. Exposure to non-ionizing electromagnetic fields (EMF), especially radiofrequency (RF) fields used in wireless communications has been suggested as a potential risk factor. For the first time, we evaluated the effects of exposure to the 2450MHz Wi-Fi signal (1h/day, 6days/week) on the reproductive system of male and female Wistar rats, pre-exposed to Wi-Fi during sexual maturation. Exposure lasted 3 weeks (males) or 2 weeks (females), then animals were mated and couples exposed for 3 more weeks. On the day before delivery, the fetuses were observed for lethality, abnormalities, and clinical signs. In our experiment, no deleterious effects of Wi-Fi exposure on rat male and female reproductive organs and fertility were observed for 1h per days. No macroscopic abnormalities in fetuses were noted, even at the critical level of 4W/kg. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Indoor Location Sensing with Invariant Wi-Fi Received Signal Strength Fingerprinting.

    Science.gov (United States)

    Husen, Mohd Nizam; Lee, Sukhan

    2016-11-11

    A method of location fingerprinting based on the Wi-Fi received signal strength (RSS) in an indoor environment is presented. The method aims to overcome the RSS instability due to varying channel disturbances in time by introducing the concept of invariant RSS statistics. The invariant RSS statistics represent here the RSS distributions collected at individual calibration locations under minimal random spatiotemporal disturbances in time. The invariant RSS statistics thus collected serve as the reference pattern classes for fingerprinting. Fingerprinting is carried out at an unknown location by identifying the reference pattern class that maximally supports the spontaneous RSS sensed from individual Wi-Fi sources. A design guideline is also presented as a rule of thumb for estimating the number of Wi-Fi signal sources required to be available for any given number of calibration locations under a certain level of random spatiotemporal disturbances. Experimental results show that the proposed method not only provides 17% higher success rate than conventional ones but also removes the need for recalibration. Furthermore, the resolution is shown finer by 40% with the execution time more than an order of magnitude faster than the conventional methods. These results are also backed up by theoretical analysis.

  15. An Android/LAMP Mobile In/Out Board Based on Wi-Fi Fingerprinting

    Directory of Open Access Journals (Sweden)

    Keith Kelley

    2011-10-01

    Full Text Available Library technology and other professionals with diverse skills must be able to locate each other during the workday, in order to most responsively serve their clients. While staff often carry cellular phones, contact can be especially challenging given the constant, highly mobile nature of library work, especially on larger campuses with variable cellular phone service. Western Michigan University (WMU Libraries has developed an Android/LAMP application that library staff may use on their increasingly prevalent Wi-Fi enabled mobile devices to “check in” at various locations where they do work, so that their colleagues may locate them as needed. The application takes advantage of WMU’s widespread Wi-Fi network, a set of free platform and software development tools and open standards, and methods from the computer science literature, and overcomes GPS and telephony limitations. This article describes the application, which is based on Wi-Fi fingerprinting, and suggests how other developers could use it and new methods from the computer science literature as starting points to create their own applications.

  16. INDOOR LOCALIZATION USING WI-FI BASED FINGERPRINTING AND TRILATERATION TECHIQUES FOR LBS APPLICATIONS

    Directory of Open Access Journals (Sweden)

    S. Chan

    2012-06-01

    Full Text Available The past few years have seen wide spread adoption of outdoor positioning services, mainly GPS, being incorporated into everyday devices such as smartphones and tablets. While outdoor positioning has been well received by the public, its indoor counterpart has been mostly limited to private use due to its higher costs and complexity for setting up the proper environment. The objective of this research is to provide an affordable mean for indoor localization using wireless local area network (WLAN Wi-Fi technology. We combined two different Wi-Fi approaches to locate a user. The first method involves the use of matching the pre-recorded received signal strength (RSS from nearby access points (AP, to the data transmitted from the user on the fly. This is commonly known as "fingerprint matching". The second approach is a distance-based trilateration approach using three known AP coordinates detected on the user's device to derive the position. The combination of the two steps enhances the accuracy of the user position in an indoor environment allowing location-based services (LBS such as mobile augmented reality (MAR to be deployed more effectively in the indoor environment. The mapping of the RSS map can also prove useful to IT planning personnel for covering locations with no Wi-Fi coverage (ie. dead spots. The experiments presented in this research helps provide a foundation for the integration of indoor with outdoor positioning to create a seamless transition experience for users.

  17. Investigation of a new handover approach in LTE and WiMAX.

    Science.gov (United States)

    Hindia, Mohammad Nour; Reza, Ahmed Wasif; Noordin, Kamarul Ariffin

    2014-01-01

    Nowadays, one of the most important challenges in heterogeneous networks is the connection consistency between the mobile station and the base stations. Furthermore, along the roaming process between the mobile station and the base station, the system performance degrades significantly due to the interferences from neighboring base stations, handovers to inaccurate base station and inappropriate technology selection. In this paper, several algorithms are proposed to improve mobile station performance and seamless mobility across the long-term evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX) technologies, along with a minimum number of redundant handovers. Firstly, the enhanced global positioning system (GPS) and the novel received signal strength (RSS) prediction approaches are suggested to predict the target base station accurately. Then, the multiple criteria with two thresholds algorithm is proposed to prioritize the selection between LTE and WiMAX as the target technology. In addition, this study also covers the intercell and cochannel interference reduction by adjusting the frequency reuse ratio 3 (FRR3) to work with LTE and WiMAX. The obtained results demonstrate high next base station prediction efficiency and high accuracy for both horizontal and vertical handovers. Moreover, the received signal strength is kept at levels higher than the threshold, while maintaining low connection cost and delay within acceptable levels. In order to highlight the combination of the proposed algorithms' performance, it is compared with the existing RSS and multiple criteria handover decision algorithms.

  18. Indoor Location Sensing with Invariant Wi-Fi Received Signal Strength Fingerprinting

    Directory of Open Access Journals (Sweden)

    Mohd Nizam Husen

    2016-11-01

    Full Text Available A method of location fingerprinting based on the Wi-Fi received signal strength (RSS in an indoor environment is presented. The method aims to overcome the RSS instability due to varying channel disturbances in time by introducing the concept of invariant RSS statistics. The invariant RSS statistics represent here the RSS distributions collected at individual calibration locations under minimal random spatiotemporal disturbances in time. The invariant RSS statistics thus collected serve as the reference pattern classes for fingerprinting. Fingerprinting is carried out at an unknown location by identifying the reference pattern class that maximally supports the spontaneous RSS sensed from individual Wi-Fi sources. A design guideline is also presented as a rule of thumb for estimating the number of Wi-Fi signal sources required to be available for any given number of calibration locations under a certain level of random spatiotemporal disturbances. Experimental results show that the proposed method not only provides 17% higher success rate than conventional ones but also removes the need for recalibration. Furthermore, the resolution is shown finer by 40% with the execution time more than an order of magnitude faster than the conventional methods. These results are also backed up by theoretical analysis.

  19. Fusion of WiFi, smartphone sensors and landmarks using the Kalman filter for indoor localization.

    Science.gov (United States)

    Chen, Zhenghua; Zou, Han; Jiang, Hao; Zhu, Qingchang; Soh, Yeng Chai; Xie, Lihua

    2015-01-05

    Location-based services (LBS) have attracted a great deal of attention recently. Outdoor localization can be solved by the GPS technique, but how to accurately and efficiently localize pedestrians in indoor environments is still a challenging problem. Recent techniques based on WiFi or pedestrian dead reckoning (PDR) have several limiting problems, such as the variation of WiFi signals and the drift of PDR. An auxiliary tool for indoor localization is landmarks, which can be easily identified based on specific sensor patterns in the environment, and this will be exploited in our proposed approach. In this work, we propose a sensor fusion framework for combining WiFi, PDR and landmarks. Since the whole system is running on a smartphone, which is resource limited, we formulate the sensor fusion problem in a linear perspective, then a Kalman filter is applied instead of a particle filter, which is widely used in the literature. Furthermore, novel techniques to enhance the accuracy of individual approaches are adopted. In the experiments, an Android app is developed for real-time indoor localization and navigation. A comparison has been made between our proposed approach and individual approaches. The results show significant improvement using our proposed framework. Our proposed system can provide an average localization accuracy of 1 m.

  20. Developing an active emergency medical service system based on WiMAX technology.

    Science.gov (United States)

    Li, Shing-Han; Cheng, Kai-An; Lu, Wen-Hui; Lin, Te-Chang

    2012-10-01

    The population structure has changed with the aging of population. In the present, elders account for 10.63% of the domestic population and the percentage is still gradually climbing. In other words, the demand for emergency services among elders in home environment is expected to grow in the future. In order to improve the efficiency and quality of emergency care, information technology should be effectively utilized to integrate medical systems and facilities, strengthen human-centered operation designs, and maximize the overall performance. The improvement in the quality and survival rate of emergency care is an important basis for better life and health of all people. Through integrated application of medical information systems and information communication technology, this study proposes a WiMAX-based emergency care system addressing the public demands for convenience, speed, safety, and human-centered operation of emergency care. This system consists of a healthcare service center, emergency medical service hospitals, and emergency ambulances. Using the wireless transmission capability of WiMAX, patients' physiological data can be transmitted from medical measurement facilities to the emergency room and emergency room doctors can provide immediate online instructions on emergency treatment via video and audio transmission. WiMAX technology enables the establishment of active emergency medical services.

  1. Wake-on-a-Schedule: Energy-aware Communication in Wi-Fi Networks

    Directory of Open Access Journals (Sweden)

    PERKOVIC, T.

    2014-02-01

    Full Text Available Excessive energy consumption of mobile device Wi-Fi (IEEE 802.11x interface is limiting its operational time on batteries, and impacts total energy consumption of electronic devices. In recent years research community has invested great effort in better efficiency of energy consumption. However, there is still a space for improvement. Wi-Fi devices connected to the single AP (Access Point compete for the medium during data exchange. However, due to the performance anomaly in 802.11 networks, a low data rate device will force all other devices connected to the AP to communicate at low rate, which will increase the total energy consumption of these devices. Wake-on-a-Schedule algorithm is proposed reducing the energy consumption of devices placed in the area with the weaker signal by scheduling the data packets for each client on the server side which will not allow clients to compete for the Wi-Fi medium. Through extensive measurements we show that our algorithm can save up to 60% of energy consumption on the client side.

  2. Rectangular Ring Antenna Excited by Circular Disc Monopole for WiMAX System

    Directory of Open Access Journals (Sweden)

    Souphanna Vongsack

    2014-01-01

    Full Text Available This research presents a rectangular ring antenna excited by a circular disc monopole (CDM mounted in front of a square reflector. The proposed antenna is designed to cover a frequency range of 2.300–5.825 GHz and thereby is suitable for WiMAX applications. Multiple parametric studies were carried out using the CST Microwave Studio simulation program. A prototype antenna was fabricated and experimented. The measurements were taken and compared with the simulation results, which indicates good agreement between both results. The prototype antenna produces an impedance bandwidth (|S11| < −10 dB that covers the WiMAX frequency range and a constant unidirectional radiation pattern (θ=0° and ∅=90°. The minimum and maximum gains are 3.7 and 8.7 dBi, respectively. The proposed antenna is of compact size and has good unidirectional radiation performance. Thus, it is very suitable for a multitude of WiMAX applications.

  3. Zingiber officinale, Piper retrofractum and Combination Induced Apoptosis and p53 Expression in Myeloma and WiDr Cell Lines

    Directory of Open Access Journals (Sweden)

    HENY EKOWATI

    2012-09-01

    Full Text Available In previous studies, Zingiber officinale, Piper retrofractum, and the combination showed cytotoxic activity, induced apoptosis, and p53 expression of HeLa, T47D, and MCF-7 cell lines. This study was conducted to investigate the cytotoxic and apoptotic activity of Zingiber officinale (ZO, Piper retrofractum (PR, and the combination as well as their effect to p53 expression on Myeloma and WiDr cells. The powder of ZO, PR, and ZO + PR combination (1:1 were macerated with 96% ethanol for 3 x 24 hours. MTT cytotoxic assay was performed on Myeloma and WiDr cell lines. Apoptotic cells were stained with ethidium bromide and acridine orange. Imunohistochemical expression of p53 was examined on Myeloma and WiDr cell lines. Doxorubicin was used as positive control in all assays. Results showed that ZO, PR, and ZO + PR combination had cytotoxic activity on Myeloma cells with IC50 of 28, 36, and 55 mg/ml respectively and WiDr cell lines with IC50 of 74, 158, and 64 mg/ml respectively, induced apoptotic activity, and increased p53 expression on Myeloma and WiDr cells. These results suggest that ZO, PR, and their combination induced Myeloma and WiDr cells in apoptosis through p53 expression.

  4. The effect of Wi-Fi electromagnetic waves in unimodal and multimodal object recognition tasks in male rats.

    Science.gov (United States)

    Hassanshahi, Amin; Shafeie, Seyed Ali; Fatemi, Iman; Hassanshahi, Elham; Allahtavakoli, Mohammad; Shabani, Mohammad; Roohbakhsh, Ali; Shamsizadeh, Ali

    2017-06-01

    Wireless internet (Wi-Fi) electromagnetic waves (2.45 GHz) have widespread usage almost everywhere, especially in our homes. Considering the recent reports about some hazardous effects of Wi-Fi signals on the nervous system, this study aimed to investigate the effect of 2.4 GHz Wi-Fi radiation on multisensory integration in rats. This experimental study was done on 80 male Wistar rats that were allocated into exposure and sham groups. Wi-Fi exposure to 2.4 GHz microwaves [in Service Set Identifier mode (23.6 dBm and 3% for power and duty cycle, respectively)] was done for 30 days (12 h/day). Cross-modal visual-tactile object recognition (CMOR) task was performed by four variations of spontaneous object recognition (SOR) test including standard SOR, tactile SOR, visual SOR, and CMOR tests. A discrimination ratio was calculated to assess the preference of animal to the novel object. The expression levels of M1 and GAT1 mRNA in the hippocampus were assessed by quantitative real-time RT-PCR. Results demonstrated that rats in Wi-Fi exposure groups could not discriminate significantly between the novel and familiar objects in any of the standard SOR, tactile SOR, visual SOR, and CMOR tests. The expression of M1 receptors increased following Wi-Fi exposure. In conclusion, results of this study showed that chronic exposure to Wi-Fi electromagnetic waves might impair both unimodal and cross-modal encoding of information.

  5. 78 FR 49290 - Oshkosh Defense, a Division of Oshkosh Corporation, Including On-Site Leased Workers From...

    Science.gov (United States)

    2013-08-13

    ... foreign country. During the reconsideration investigation, the subject firm addressed a newspaper article... AARF axles), including component parts. The workers are not separately identifiable by article produced... in production of, and administrative functions in support of, the articles produced by the subject...

  6. Pemodelan dan Verifikasi Formal Pengaruh Mobility pattern Terhadap Handoff Latency pada Jaringan WiMAX

    Directory of Open Access Journals (Sweden)

    I Nym Saputra Wahyu Wijaya

    2016-01-01

    Full Text Available In order to decrease handoff latency and increase the successful of HHO conventional scheme, a development of handover scheme is done in standard protocol WiMAX IEEE 802.16e by adding mobility pattern. The superiority of handover scheme with mobility pattern can reduce handoff latency up to 50%, mean while the weakness of this scheme is a wrong act in determining target base station are often happen. Simulation can not showing the cause of that error. So, we do formal verification in to hard handover model with mobility pattern.             In this research, behaviour system is modeled with continuous-time Markov chain (CTMC. The model is foccused to aproximating the influence of mobility pattern in to handoff latency from WiMAX hard handover mechanism. In order to set up a series markov chain models handover system can follow steps, such as: represents the state space, give a number in all transitions, generate the rate transition matrix (infinitesimal generator.             Probabilistic model checking in the research are using quantitative properties and qualitative properties. Formal verification concerning properties has relation with handover in WiMAX network showing that 70% from mobile station which doing scanning with mobility pattern are success doing handover. 24% of them doing scanning conventional as a result of wrongness in act determining target base station, so handoff latency which is pictured will bigger than a system that is only use conventional scanning method.

  7. Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency

    Directory of Open Access Journals (Sweden)

    Vasilis Maglogiannis

    2017-08-01

    Full Text Available On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP announced standards that permit the operation of Long Term Evolution (LTE in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner.

  8. Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency

    Science.gov (United States)

    Naudts, Dries; Shahid, Adnan; Giannoulis, Spilios; Laermans, Eric

    2017-01-01

    On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner. PMID:28858243

  9. A Floor-Map-Aided WiFi/Pseudo-Odometry Integration Algorithm for an Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2015-03-01

    Full Text Available This paper proposes a scheme for indoor positioning by fusing floor map, WiFi and smartphone sensor data to provide meter-level positioning without additional infrastructure. A topology-constrained K nearest neighbor (KNN algorithm based on a floor map layout provides the coordinates required to integrate WiFi data with pseudo-odometry (P-O measurements simulated using a pedestrian dead reckoning (PDR approach. One method of further improving the positioning accuracy is to use a more effective multi-threshold step detection algorithm, as proposed by the authors. The “go and back” phenomenon caused by incorrect matching of the reference points (RPs of a WiFi algorithm is eliminated using an adaptive fading-factor-based extended Kalman filter (EKF, taking WiFi positioning coordinates, P-O measurements and fused heading angles as observations. The “cross-wall” problem is solved based on the development of a floor-map-aided particle filter algorithm by weighting the particles, thereby also eliminating the gross-error effects originating from WiFi or P-O measurements. The performance observed in a field experiment performed on the fourth floor of the School of Environmental Science and Spatial Informatics (SESSI building on the China University of Mining and Technology (CUMT campus confirms that the proposed scheme can reliably achieve meter-level positioning.

  10. Hybrid algorithm: A cost efficient solution for ONU placement in Fiber-Wireless (FiWi) network

    Science.gov (United States)

    Bhatt, Uma Rathore; Chouhan, Nitin; Upadhyay, Raksha

    2015-03-01

    Fiber-Wireless (FiWi) network is a promising access technology as it integrates the technical merits of optical and wireless access networks. FiWi provides large bandwidth and high stability of optical network and lower cost of wireless network respectively. Therefore, FiWi gives users to access broadband services in an "anywhere-anytime" way. One of the key issues in FiWi network is its deployment cost, which depends on the number of ONUs in the network. Therefore optimal placement of ONUs is desirable to design a cost effective network. In this paper, we propose an algorithm for optimal placement of ONUs. First we place an ONU in the center of each grid then we form a set of wireless routers associated with each ONU according to wireless hop number. The number of ONUs are minimized in such a way, that all the wireless routers can communicate to at least one of the ONUs. The number of ONUs in the network further reduced by using genetic algorithm. The effectiveness of the proposed algorithm is tested by considering Internet traffic as well as peer-to-peer (p2p) traffic in the network, which is a current need. Simulation results show that the proposed algorithm is better than existing algorithms in minimizing number of ONUs in the network for both types of traffics. Hence proposed algorithm offers cost effective solution to design the FiWi network.

  11. Wi-Fi Hotspot Auto-Discovery: A Practical & Energy-Aware System for Smart Objects using Cellular Signals

    Directory of Open Access Journals (Sweden)

    Nithyananthan Poosamani

    2015-08-01

    Full Text Available The Internet of Things (IoT paradigm aims to interconnect a variety of heterogeneous Smart Objects (SO using energy-efficient methodologies and standard communication protocols. A majority of consumer devices sold today come equipped with wireless LAN and cellular technology to connect with the world-wide network. To discover Wi-Fi hot spots, there is a need for constant scanning of Wi-Fi radio in these devices and results in significant battery drain. We present PRiSM, a practical system to automatically locate Wi-Fi hotspots while Wi-Fi radio is turned off, by using the statistical characteristics of cellular signals. Cellular signals are received at zero extra cost in mobile devices and hence PRiSM is highly energy-efficient. It is a lightweight client-side only implementation and needs no prior knowledge on floor plans or wireless infrastructure. We implement PRiSM on Android-based devices and show up to 96% of energy savings in Wi-Fi sensing operations which is equivalent to saving up to 16% of total battery capacity, together with an average prediction accuracy of up to 98%.

  12. A floor-map-aided WiFi/pseudo-odometry integration algorithm for an indoor positioning system.

    Science.gov (United States)

    Wang, Jian; Hu, Andong; Liu, Chunyan; Li, Xin

    2015-03-24

    This paper proposes a scheme for indoor positioning by fusing floor map, WiFi and smartphone sensor data to provide meter-level positioning without additional infrastructure. A topology-constrained K nearest neighbor (KNN) algorithm based on a floor map layout provides the coordinates required to integrate WiFi data with pseudo-odometry (P-O) measurements simulated using a pedestrian dead reckoning (PDR) approach. One method of further improving the positioning accuracy is to use a more effective multi-threshold step detection algorithm, as proposed by the authors. The "go and back" phenomenon caused by incorrect matching of the reference points (RPs) of a WiFi algorithm is eliminated using an adaptive fading-factor-based extended Kalman filter (EKF), taking WiFi positioning coordinates, P-O measurements and fused heading angles as observations. The "cross-wall" problem is solved based on the development of a floor-map-aided particle filter algorithm by weighting the particles, thereby also eliminating the gross-error effects originating from WiFi or P-O measurements. The performance observed in a field experiment performed on the fourth floor of the School of Environmental Science and Spatial Informatics (SESSI) building on the China University of Mining and Technology (CUMT) campus confirms that the proposed scheme can reliably achieve meter-level positioning.

  13. 23rd WiN Global Annual Conference: Women in Nuclear meet Atoms for Peace. Programme and Abstracts

    International Nuclear Information System (INIS)

    2015-01-01

    Women in Nuclear (WiN) Global is a worldwide non-profit-making association made up mostly of female professionals working in the various fields of nuclear energy and radiation applications. WiN Global aims to promote understanding and public awareness of the benefits of nuclear and radiation applications through a series of active networks, both national and international. It has approximately 25 000 members from more than 100 countries, organized in national, regional and international chapters. Every year, a chapter of WiN Global organizes the annual conference, which is a unique occasion for the WiN Global community to meet. The 23. WiN Global Annual Conference will highlight the vital role women play in all applications of nuclear science and technology. At the same time, it will provide opportunities for networking, exchanging ideas, technical visits and obtaining the most up-to-date information on the nuclear programmes and facilities around the world as well as on employment opportunities at the International Atomic Energy Agency (IAEA).

  14. Head to head battle of TV white space and WiFi for connecting developing regions

    CSIR Research Space (South Africa)

    Johnson, David

    2016-12-01

    Full Text Available Fi network for rural communities," 2011 IEEE GLOBECOM Workshops (GC Wkshps), Houston, TX, 2011, pp. 1050-1055. 8. L. Subramanian, S.Surana, A.Sheth, S. Nedevschi, R. Patra, M. Ho, and E. Brewer, “Re- thinking wireless for the developing world,” In ACM... Workshops (GC Wkshps), Houston, TX, 2011, pp. 1039-1044. 14. R. Patra, S. Nedevschi, S. Surana, A. Sheth, L. Subramanian, and E. Brewer, “WiLdnet: design and implementation of high performance wifi based long distance networks,” In Proceedings...

  15. EMI and BER/PER Analysis of Wi-Fi and Bluetooth Communication for CRIP Platform

    DEFF Research Database (Denmark)

    Ravelo, Blaise; Cabral, Jorge; Wagner, Stefan Rahr

    This paper is devoted to the characterization of the electromagnetic interference (EMI) effects on wireless communication devices for telemedicine healthcare application. The proposed wireless system operates at the 2.4GHz ISM band with a hardware interface communicating by Wi-Fi and BLE (Bluetooth...... Low-Energy) to the medical devices and a USB interface to NFC/RFID (ISO/IEC-18092) and biometrics (ISO/IEC-19794) readers to securely identify medical staff. A scenario with configuration of modules attached to the patient and used by the nurse in the medical care room is considered. The channel ITU...

  16. [Research on WiFi-based wireless microscopy on a mobile phone and its application].

    Science.gov (United States)

    Hailan, Jin; Jing, Liu

    2012-11-01

    We proposed and realized a new device that acquires microscopic image wirelessly based on mobile phone and WiFi system. The mobile terminals could record, display and store the image from the far end via the wireless LAN. Using this system, a series of conceptual experiments on monitoring the microscopic images of common objects and liver cancer cells were successfully demonstrated. This system is expected to have important value in the experimental investigations on wirelessly monitoring the cell culture, and small insect etc.

  17. Three-dimensional microfabricated broadband patch antenna for wiGig applications

    OpenAIRE

    Mopidevi, Hema Swaroop; Hurneli, H. V.; Cagatay, E.; Biyikli, N.; Imbert Villà, Marc; Romeu Robert, Jordi; Jofre Roca, Lluís; Cetiner, Bedri Artug

    2014-01-01

    The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (epsilon(r) = 3.9, tan delta = 0.0002 at 60 GHz), on top of which an SU-8-based three-dimensional (3...

  18. Mobile Sensing of Pedestrian Flocks in Indoor Environments using WiFi Signals

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Wirz, Martin; Roggen, Daniel

    2012-01-01

    a cohesive whole - specifically flocks - with clustering approaches operating on three different feature sets derived from WiFi signals which are comparatively analysed. Automatic detection of flocks has several important applications, including social and psychological sensing and emergency research studies....... We use a dataset comprising 16 subjects forming one to four flocks walking in a building on single and multiple floors. For the detection of flocks we achieved an average F-measure accuracy of up to 85 percent. We report on the advantages and drawbacks of the three different types of feature sets...

  19. Real-Time and Accurate Indoor Localization with Fusion Model of Wi-Fi Fingerprint and Motion Particle Filter

    Directory of Open Access Journals (Sweden)

    Xinlong Jiang

    2015-01-01

    Full Text Available As the development of Indoor Location Based Service (Indoor LBS, a timely localization and smooth tracking with high accuracy are desperately needed. Unfortunately, any single method cannot meet the requirement of both high accuracy and real-time ability at the same time. In this paper, we propose a fusion location framework with Particle Filter using Wi-Fi signals and motion sensors. In this framework, we use Extreme Learning Machine (ELM regression algorithm to predict position based on motion sensors and use Wi-Fi fingerprint location result to solve the error accumulation of motion sensors based location occasionally with Particle Filter. The experiments show that the trajectory is smoother as the real one than the traditional Wi-Fi fingerprint method.

  20. Optimizing WiMAX: Mitigating Co-Channel Interference for Maximum Spectral Efficiency

    Directory of Open Access Journals (Sweden)

    ABDUL QADIR ANSARI

    2016-10-01

    Full Text Available The efficient use of radio spectrum is one of the most important issues in wireless networks because spectrum is generally limited and wireless environment is constrained to channel interference. To cope up and for increased usefulness of radio spectrum wireless networks use frequency reuse technique. The frequency reuse technique allows the use of same frequency band in different cells of same network considering inter-cell distance and resulting interference level. WiMAX (Worldwide Interoperability for Microwave Access PHY profile is designed to use FRF (Frequency Reuse Factor of one. When FRF of one is used it results in an improved spectral efficacy but also results in CCI (Co-Channel interference at cell boundaries. The effect of interference is always required to be measured so that some averaging/ minimization techniques may be incorporated to keep the interference level up to some acceptable threshold in wireless environment. In this paper, we have analyzed, that how effectively CCI impact can be mitigated by using different subcarrier permutation types presented in IEEE 802.16 standard. A simulation based analysis is presented wherein impact of using same and different permutation base in adjacent cells in a WiMAX network on CCI, under varying load conditions is analyzed. We have further studied the effect of permutation base in environment where frequency reuse technique is used in conjunction with cell sectoring for better utilization of radio spectrum.

  1. Wi-Fi and GSM Based Motion Sensor for Home Security System Apllication

    Science.gov (United States)

    Huzaimy Jusoh, Mohamad; Jamali, Muhammad Firdaus Bin; Zainal Abidin, Ahmad Faizal bin; Asari Sulaiman, Ahmad; Fahmi Hussin, Mohamad

    2015-11-01

    The Wi-Fi and GSM based home security system is a system designed to reduce the high rates of crimes in most personal housing. The overall project consists of three major parts; the input part that consists of sensors, the software part that operates the entire hardware structure, and the output part, which consists of camera, alarm system, and micro secure digital (SD) data storage card. It is based on the principle of infrared radiation generated by a human body heat which trigger the passive infrared (PIR) sensor. The microcontroller processes the received signal, then trigger the buzzer alarm, camera and alerts the home owner through an SMS. Once triggered, the camera will capture the image of the intruder and the image will be saved in SD card. As alert to the user (away), the Global System for Mobile Communication (GSM) will send the Short Message Service (SMS) from the device to the user's mobile phone. The image will be sent to Dropbox data cloud storage via Wi-Fi for further clarification. The prototype was successfully developed, tested and has been installed at residential area in Taman Cahaya Alam, Section U12, Shah Alam, Malaysia.

  2. Autonomous WiFi Sensor for Heating Systems in the Internet of Things

    Directory of Open Access Journals (Sweden)

    C. A. Trasviña-Moreno

    2016-01-01

    Full Text Available In smart cities and home applications, the use of Wireless Sensor Networks to extract environmental data becomes more common with the passing of time. These sensors are used for a wide array of applications, but mainly to manage energy consumption in domestic buildings. One of the key energy consumers in households is heating systems. To monitor them, sensors are used with wireless communication protocols, like ZigBee, to transmit data to a central processing unit (CPU. WiFi communications, on the contrary, are rarely seen in these implementations due to its high energy consumption, although almost in every home one can find such networks. Yet, with the Internet of Things (IoT, new revisions of the standard have arisen which enable this technology for wireless sensing. To validate this theory and fill a technological necessity, this proposal is presented. In this work, the design and implementation of an autonomous WiFi sensor, paired with thermoelectric energy harvesting, are presented as an IoT solution for monitoring heating devices. For this, a thorough analysis of the proposed architecture is presented. Tests regarding energy consumption and generation, efficiency, and real world scenario trials are done. Finalizing, a comparison between the obtained results and current implementations is shown.

  3. Error analysis for RADAR neighbor matching localization in linear logarithmic strength varying Wi-Fi environment.

    Science.gov (United States)

    Zhou, Mu; Tian, Zengshan; Xu, Kunjie; Yu, Xiang; Wu, Haibo

    2014-01-01

    This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs) in logarithmic received signal strength (RSS) varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs) as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future.

  4. Implementation of Wi-Fi Signal Sampling on an Android Smartphone for Indoor Positioning Systems.

    Science.gov (United States)

    Liu, Hung-Huan; Liu, Chun

    2017-12-21

    Collecting and maintaining radio fingerprint for wireless indoor positioning systems involves considerable time and labor. We have proposed the quick radio fingerprint collection (QRFC) algorithm which employed the built-in accelerometer of Android smartphones to implement step detection in order to assist in collecting radio fingerprints. In the present study, we divided the algorithm into moving sampling (MS) and stepped MS (SMS), and describe the implementation of both algorithms and their comparison. Technical details and common errors concerning the use of Android smartphones to collect Wi-Fi radio beacons were surveyed and discussed. The results of signal sampling experiments performed in a hallway measuring 54 m in length showed that in terms of the amount of time required to complete collection of access point (AP) signals, static sampling (SS; a traditional procedure for collecting Wi-Fi signals) took at least 2 h, whereas MS and SMS took approximately 150 and 300 s, respectively. Notably, AP signals obtained through MS and SMS were comparable to those obtained through SS in terms of the distribution of received signal strength indicator (RSSI) and positioning accuracy. Therefore, MS and SMS are recommended instead of SS as signal sampling procedures for indoor positioning algorithms.

  5. Error Analysis for RADAR Neighbor Matching Localization in Linear Logarithmic Strength Varying Wi-Fi Environment

    Directory of Open Access Journals (Sweden)

    Mu Zhou

    2014-01-01

    Full Text Available This paper studies the statistical errors for the fingerprint-based RADAR neighbor matching localization with the linearly calibrated reference points (RPs in logarithmic received signal strength (RSS varying Wi-Fi environment. To the best of our knowledge, little comprehensive analysis work has appeared on the error performance of neighbor matching localization with respect to the deployment of RPs. However, in order to achieve the efficient and reliable location-based services (LBSs as well as the ubiquitous context-awareness in Wi-Fi environment, much attention has to be paid to the highly accurate and cost-efficient localization systems. To this end, the statistical errors by the widely used neighbor matching localization are significantly discussed in this paper to examine the inherent mathematical relations between the localization errors and the locations of RPs by using a basic linear logarithmic strength varying model. Furthermore, based on the mathematical demonstrations and some testing results, the closed-form solutions to the statistical errors by RADAR neighbor matching localization can be an effective tool to explore alternative deployment of fingerprint-based neighbor matching localization systems in the future.

  6. Design of a dual band metamaterial absorber for Wi-Fi bands

    Science.gov (United States)

    Alkurt, Fatih Özkan; Baǧmancı, Mehmet; Karaaslan, Muharrem; Bakır, Mehmet; Altıntaş, Olcay; Karadaǧ, Faruk; Akgöl, Oǧuzhan; Ünal, Emin

    2018-02-01

    The goal of this work is to design and fabrication of a dual band metamaterial based absorber for Wireless Fidelity (Wi-Fi) bands. Wi-Fi has two different operating frequencies such as 2.45 GHz and 5 GHz. A dual band absorber is proposed and the proposed structure consists of two layered unit cells, and different sized square split ring (SSR) resonators located on each layers. Copper is used for metal layer and resonator structure, FR-4 is used as substrate layer in the proposed structure. This designed dual band metamaterial absorber is used in the wireless frequency bands which has two center frequencies such as 2.45 GHz and 5 GHz. Finite Integration Technique (FIT) based simulation software used and according to FIT based simulation results, the absorption peak in the 2.45 GHz is about 90% and the another frequency 5 GHz has absorption peak near 99%. In addition, this proposed structure has a potential for energy harvesting applications in future works.

  7. Spectrum Graph Coloring and Applications to Wi-Fi Channel Assignment

    Directory of Open Access Journals (Sweden)

    David Orden

    2018-03-01

    Full Text Available We introduce and explore a family of vertex-coloring problems, which, surprisingly enough, have not been considered before despite stemming from the problem of Wi-Fi channel assignment. Given a spectrum of colors, endowed with a matrix of interferences between each pair of colors, the Threshold Spectrum Coloring problem fixes the number of colors available and aims to minimize the interference threshold, i.e., the maximum of the interferences at the vertices. Conversely, the Chromatic Spectrum Coloring problem fixes a threshold and aims to minimize the number of colors for which respecting that threshold is possible. As the main theoretical results, we prove tight upper bounds for the solutions to each problem. Since both problems turn out to be NP-hard, we complete the scene with experimental results. We propose a DSATUR-based heuristic and study its performance to minimize the maximum vertex interference in Wi-Fi channel assignment, both for randomly-generated graphs and for a real-world scenario. Further, for all these graphs, we experimentally check the goodness of the theoretical bounds.

  8. SAR in a child voxel phantom from exposure to wireless computer networks (Wi-Fi).

    Science.gov (United States)

    Findlay, R P; Dimbylow, P J

    2010-08-07

    Specific energy absorption rate (SAR) values have been calculated in a 10 year old sitting voxel model from exposure to electromagnetic fields at 2.4 and 5 GHz, frequencies commonly used by Wi-Fi devices. Both plane-wave exposure of the model and irradiation from antennas in the near field were investigated for a variety of exposure conditions. In all situations studied, the SAR values calculated were considerably below basic restrictions. For a typical Wi-Fi exposure scenario using an inverted F antenna operating at 100 mW, a duty factor of 0.1 and an antenna-body separation of 34 cm, the maximum peak localized SAR was found to be 3.99 mW kg(-1) in the torso region. At 2.4 GHz, using a power of 100 mW and a duty factor of 1, the highest localized SAR value in the head was calculated as 5.7 mW kg(-1). This represents less than 1% of the SAR previously calculated in the head for a typical mobile phone exposure condition.

  9. PENGEMBANGAN VARIATIF RANCANGAN ANTENA PANEL MICROSTRIP TAPERED PATCH DALAM SISTEM KOMUNIKASI WI-FI

    Directory of Open Access Journals (Sweden)

    Putu Artawan

    2013-04-01

    Full Text Available Pada penelitian ini dilakukan pengembangan rancangan antena microstrip tapered patch untuk dilakukan pengukuran parameternya sebagai karakteristik dari antena Microstrip. Penelitian ini sebagai pengembangan variatif rancangan untuk memperoleh hasil yang lebih optimal. Metode eksperiment dilakukan dalam penelitian ini. Tahap pengerjaanya yaitu membuat desain rancangan antena sesuai persamaan yang ada yang kemudian dirancang dengan metode UV Photoresist laminate. Hasil rancangan antena diukur untuk mendapatkan karakteristik sebagai parameter antena meliputi frekuensi (bandwidth, SWR, VSWR, koofesien refleksi, pola radiasi dan penguatan (gain serta nilai HPBW. Nilai-nilai tersebut mencerminkan karakter dari sebuah antena sebagai parameter antena yang layak diimplementasikan dalam sistem komunikasi internet dengan sistem wi-fi. Hasil penelitian ini meliputi: nilai lebar pita (bandwidth = 0.21 GHz, VSWR = 1,23, SWR = 1,79,  return loss = -20,00 dB, koofesien refleksi = 0,10 dan grafik pola radiasi dengan penguatan (gain = 17 dB (polarisasi vertikal, 20 dB (polarisasi horizontal. Nilai Half Power Beamwidth (HPBW 820 untuk pola radiasi vertikal dan pola radiasi horizontal. Kesalahan (error hasil pengukuran 0,12% dengan keseksamaan 99,88%. Hasil ini memberikan indikasi sebagai rancangan antena yang layak untuk sistem komunikasi wi-fi. Penelitian ini sebagai salah satu aplikasi ilmu Fisika dalam dunia teknologi informasi dan diharapkan dapat bermanfaat sebagai dinamika wahana salah satu produk penerapan ilmu Fisika dalam bidang Teknologi Informasi.

  10. The WAGGS project - I. The WiFeS Atlas of Galactic Globular cluster Spectra

    Science.gov (United States)

    Usher, Christopher; Pastorello, Nicola; Bellstedt, Sabine; Alabi, Adebusola; Cerulo, Pierluigi; Chevalier, Leonie; Fraser-McKelvie, Amelia; Penny, Samantha; Foster, Caroline; McDermid, Richard M.; Schiavon, Ricardo P.; Villaume, Alexa

    2017-07-01

    We present the WiFeS Atlas of Galactic Globular cluster Spectra, a library of integrated spectra of Milky Way and Local Group globular clusters. We used the WiFeS integral field spectrograph on the Australian National University 2.3 m telescope to observe the central regions of 64 Milky Way globular clusters and 22 globular clusters hosted by the Milky Way's low-mass satellite galaxies. The spectra have wider wavelength coverage (3300-9050 Å) and higher spectral resolution (R = 6800) than existing spectral libraries of Milky Way globular clusters. By including Large and Small Magellanic Cloud star clusters, we extend the coverage of parameter space of existing libraries towards young and intermediate ages. While testing stellar population synthesis models and analysis techniques is the main aim of this library, the observations may also further our understanding of the stellar populations of Local Group globular clusters and make possible the direct comparison of extragalactic globular cluster integrated light observations with well-understood globular clusters in the Milky Way. The integrated spectra are publicly available via the project website.

  11. The Role of the WI-38 Cell Strain in Saving Lives and Reducing Morbidity

    Directory of Open Access Journals (Sweden)

    S. J. Olshansky

    2017-03-01

    Full Text Available The modern success story of vaccinations involves a historical chain of events that transformed the discovery that vaccines worked, to administering them to the population. We estimate the number of lives saved and morbidity reduction associated with the discovery of the first human cell strain used for the production of licensed human virus vaccines, known as WI-38. The diseases studied include poliomyelitis, measles, mumps, rubella, varicella (chicken pox, herpes zoster, adenovirus, rabies and Hepatitis A. The number of preventable cases and deaths in the U.S. and across the globe was assessed by holding prevalence rates and disease-specific death rates constant from 1960–2015. Results indicate that the total number of cases of poliomyelitis, measles, mumps, rubella, varicella, adenovirus, rabies and hepatitis A averted or treated with WI-38 related vaccines was 198 million in the U.S. and 4.5 billion globally (720 million in Africa; 387 million in Latin America and the Caribbean; 2.7 billion in Asia; and 455 million in Europe. The total number of deaths averted from these same diseases was approximately 450,000 in the U.S., and 10.3 million globally (1.6 million in Africa; 886 thousand in Latin America and the Caribbean; 6.2 million in Asia; and 1.0 million in Europe.

  12. WiFi Localization Based on IEEE 802.11 RTS/CTS Mechanism

    Directory of Open Access Journals (Sweden)

    Zhe Cui

    2015-11-01

    Full Text Available Location Based Services are providing one of the fastest growing market segments today. While the most common technique for location determination is GPS, several alternative approaches have been proposed for Wi-Fi environments, based on time of flight, signal strength, etc. Time based techniques not only require accurate timestamping mechanisms, but also precise and synchronized clocks, which is quite difficult and expensive in industry. On the other hand, signal strength based methods need a lot of ground truth data. These method also require time consuming work and efforts before the system comes into use. In considerations of costs and time consumption, we present in this paper an approach for determining the location of a general Wi-Fi device combining RTS/CTS and TDoA techniques. The proposed model is deployable in various environments and contains two different methods, with clock mapping functions and asynchronized clocks. We also explain limitations of current round trip time (RTT based RTS/CTS systems. Extensive experiments have been conducted and demonstrated how an accuracy of about one foot can be obtained and also the assumption of RTT measurements have been verified.

  13. Dual Band Metamaterial Antenna For LTE/Bluetooth/WiMAX System.

    Science.gov (United States)

    Hasan, Md Mehedi; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

    2018-01-19

    A compact metamaterial inspired antenna operate at LTE, Bluetooth and WiMAX frequency band is introduced in this paper. For the lower band, the design utilizes an outer square metallic strip forcing the patch to radiate as an equivalent magnetic-current loop. For the upper band, another magnetic current loop is created by adding metamaterial structure near the feed line on the patch. The metamaterial inspired antenna dimension of 42 × 32 mm 2 compatible to wireless devices. Finite integration technique based CST Microwave Studio simulator has been used to design and numerical investigation as well as lumped circuit model of the metamaterial antenna is explained with proper mathematical derivation. The achieved measured dual band operation of the conventional antenna are sequentially, 0.561~0.578 GHz, 2.346~2.906 GHz, and 2.91~3.49 GHz, whereas the metamaterial inspired antenna shows dual-band operation from 0.60~0.64 GHz, 2.67~3.40 GHz and 3.61~3.67 GHz, respectively. Therefore, the metamaterial antenna is applicable for LTE and WiMAX applications. Besides, the measured metamaterial antenna gains of 0.15~3.81 dBi and 3.47~3.75 dBi, respectively for the frequency band of 2.67~3.40 GHz and 3.61~3.67 GHz.

  14. The 'WiFi' otoplasty : Combined concentric posterior microchondrectomies and sutures for correction of prominent ears.

    Science.gov (United States)

    Hendrickx, Benoit I M M; Hamdi, Moustapha; Zeltzer, Assaf; Greensmith, Andrew

    2018-02-19

    Prominent ears are by far the most common congenital ear deformity. Many techniques have been described using one or a combination of 3 basic methods: cartilage cutting, cartilage weakening and pure cartilage shaping techniques. The ideal otoplasty technique should yield a natural correction of the deformity, with low recurrence rates and with little risk of complications. A new cartilage shaping technique using closing wedge concentric microchondrectomies through an entirely posterior approach is presented. Between 2006 and 2017, 200 bilateral otoplasties using this 'WiFi' pattern technique were performed. This technique combined with Mustarde sutures is based on the excision of concentric partial thickness cartilage wedges designed in the pattern of the WiFi symbol. There were no major complications such as anterior skin necrosis and no returns to theatre for infections or haematomas. 3 patients (1.5%) had complete recurrence of the deformity and 10 patients (5%) had to undergo a minor revision for recurrence at the upper pole. 5 patients have had exposure of the end of the permanent upper pole scapho-temporal suture more than 3 months after surgery requiring simple outpatient suture trimming/removal without any recurrence of results. Palpable or bridging sutures were present upon clinical examination in 10 patients (5%) but did not require revision surgery. Here, we describe a fast, safe and reliable technique for otoplasty with no need for extensive dissection, which is applicable to the full range of deformity. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  15. Field Study of all GSM and WiFi Networks in Amman City from Geospatial Perspective

    Science.gov (United States)

    Hawarey, Mosab; Alibrahim, Mustafa; Jetto, Hamza; Salah Mahmoud, Firas

    2016-04-01

    A thorough field study over multiple months has been conducted in the streets of Amman, the capital city of Jordan, in order to collect massive amounts of GSM and WiFi data and analyze them from geospatial perspective. Some interesting realities have been detected; e.g. the North and West of Amman are much better served by GSM operators than the East, South, and Center. Also, the security measures taken to protect WiFi networks in the North and West are much better than those in the East, South, and Center. This has led to the recognition of an interesting pattern that groups the North and West together, while the East, South, and Center constitute another group. Extremely interesting finding was found; the GSM signals are so strong at certain locations that they constitute direct lethal threat to human health; it is scientifically documented that such strengths would lead to certain human cell mutations and cancer. The exact locations and contributors of such hazards will be disclosed in this paper for the first time. Many tabular and graphical presentations of the data will be presented.

  16. LiftingWiSe: A Lifting-Based Efficient Data Processing Technique in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Emad Aboelela

    2014-08-01

    Full Text Available Monitoring thousands of objects which are deployed over large-hard-to-reach areas, is an important application of the wireless sensor networks (WSNs. Such an application requires disseminating a large amount of data within the WSN. This data includes, but is not limited to, the object’s location and the environment conditions at that location. WSNs require efficient data processing and dissemination processes due to the limited storage, processing power, and energy available in the WSN nodes. The aim of this paper is to propose a data processing technique that can work under constrained storage, processing, and energy resource conditions. The proposed technique utilizes the lifting procedure in processing the disseminated data. Lifting is usually used in discrete wavelet transform (DWT operations. The proposed technique is referred to as LiftingWiSe, which stands for Lifting-based efficient data processing technique for Wireless Sensor Networks. LiftingWiSe has been tested and compared to other relevant techniques from the literature. The test has been conducted via a simulation of the monitored field and the deployed wireless sensor network nodes. The simulation results have been analyzed and discussed.

  17. SeaShark and Starfish opertional data processing schemes for AVHRR and SeaWiFs

    Science.gov (United States)

    Flowerdew, R. J.; Corlyon, Anaa M.; Greer, W. A. D.; Newby, Steve J.; Winder, C. P.

    1997-02-01

    SeaShark is an operational software package for processing, archiving and cataloguing AVHRR and SeaWiFS data using an operator friendly GUI. Upon receipt of a customer order, it produces standard AVHRR data products, including Sea Surface Temperature (SST) and it has recently been modified to include SeaWiFS level 2 data processing. This uses an atmospheric correction scheme developed by the Plymouth Marine Laboratory, UK (PML) that builds upon the standard Gordon and Wang approach to be applicable over both case 1 and case 2 waters. Higher level products are then generated using PML algorithms, including chlorophyll a, a CZCS-type pigment, Kd, and suspended particulate matter. Outputs are in CEOS-compatible format. The software also produces fast delivery products (FDPs) of chlorophyll a and SST. These FDPs are combined in the StarFish software package to provide maps indicating potential location of phytoplankton and the preferred thermal environment of certain pelagic fish species. Fishing vessels may obtain these maps over Inmarsat, allowing them to achieve a greater efficiency hence lower cost.

  18. Performance Analysis of VoIP Traffic in WiMAX using Various Service Classes

    Science.gov (United States)

    Anouari, Tarik; Haqiq, Abdelkrim

    2012-08-01

    Worldwide Interoperability for Microwave Access (WiMAX) is currently one of the hottest technologies in wireless, it is a standard-based on the IEEE 802.16 wireless technology that provides high throughput broadband connections over long distance, which supports Point to MultiPoint (PMP) broadband wireless access. In parallel, Voice over Internet Protocol is a promising new technology which provides access to voice communication over internet protocol based network, it becomes an alternative to public switched telephone networks due to its capability of transmission of voice as packets over IP networks. Therefore VoIP is largely intolerant of delay and hence it needs a high priority transmission. In this paper we investigate the performances of the most common VoIP codecs, which are G711, G7231 and G729 over a WiMAX network using various service classes and NOAH as a transport protocol. To analyze the QoS parameters, the popular network simulator ns2 was used. Various parameters that determine QoS of real life usage scenarios and traffic flows of applications is analyzed. The objective is to compare different types of service classes with respect to the QoS parameters, such as, throughput, average jitter and average delay.

  19. I/O Standard Based Thermal/Energy Efficient Green Communication For Wi-Fi Protected Access on FPGA

    DEFF Research Database (Denmark)

    Kumar, Tanesh; Pandey, Bishwajeet; Das, Teerath

    2014-01-01

    In this paper, we analyzed how does life and reliability of an integrated circuit is affected when it is operated in different regions under different temperatures. We have taken Fibonacci generator as our target circuit and LVCMOS as I/O standards. WPA and WPA2 (Wi-Fi Protected Access) key can...... be generated with Fibonacci generator. Here, thermal efficient green Fibonacci Generator is used to generate key for Wi-Fi Protected Access in order to make green communication possible under different room temperature. By analysis it is observed that at standard normal temperature (21degrees C), LVCMOS12 have...

  20. SeaWiFS Deep Blue Aerosol Optical Depth and Angstrom Exponent Daily Level 3 Data Gridded at 0.5 Degrees V004

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS Deep Blue Level 3 Product contains daily global gridded (0.5 x 0.5 deg) data derived from SeaWiFS Deep Blue Level 2 data. In most cases, each data field...

  1. Moderate Dose of Trolox Preventing the Deleterious Effects of Wi-Fi Radiation on Spermatozoa In vitro through Reduction of Oxidative Stress Damage.

    Science.gov (United States)

    Ding, Shang-Shu; Sun, Ping; Zhang, Zhou; Liu, Xiang; Tian, Hong; Huo, Yong-Wei; Wang, Li-Rong; Han, Yan; Xing, Jun-Ping

    2018-02-20

    The worsening of semen quality, due to the application of Wi-Fi, can be ameliorated by Vitamin E. This study aimed to demonstrate whether a moderate dose of trolox, a new Vitamin E, inhibits oxidative damage on sperms in vitro after exposure to Wi-Fi radiation. Each of the twenty qualified semen, gathered from June to October 2014 in eugenics clinic, was separated into four aliquots, including sham, Wi-Fi-exposed, Wi-Fi plus 5 mmol/L trolox, and Wi-Fi plus 10 mmol/L trolox groups. At 0 min, all baseline parameters of the 20 samples were measured in sequence. Reactive oxygen species, glutathione, and superoxide dismutase were evaluated in the four aliquots at 45 and 90 min, as were sperm DNA fragments, sperm mitochondrial potential, relative amplification of sperm mitochondrial DNA, sperm vitality, and progressive and immotility sperm. The parameters were analyzed by one-way analysis of variance and Tukey's posttest. Among Wi-Fi plus 5 mmol/L trolox, Wi-Fi-exposed and Wi-Fi plus 10 mmol/L trolox groups, reactive oxygen species levels (45 min: 3.80 ± 0.41 RLU·10 -6 ·ml -1 vs. 7.50 ± 0.35 RLU·10 -6 ·ml -1 vs. 6.70 ± 0.47 RLU·10 -6 ·ml -1 , P electromagnetic radiation-induced oxidative stress.

  2. Round fruit shape in WI7239 cucumber is controlled by two interacting quantitative trait loci with one putatively encoding a tomato SUN homolog

    Science.gov (United States)

    Fruit size and shape is an important quality trait in cucumber breeding, yet its genetic basis remains poorly understood. In the present study, we conducted QTL mapping on round fruit shape in cucumber with F2 and F2:3 segregating populations from the cross between WI7238 (long fruit) and WI7239 (ro...

  3. SeaWiFS Deep Blue Aerosol Optical Thickness Monthly Level 3 Climatology Data Gridded at 0.5 Degrees V004

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS Deep Blue Level 3 Monthly Climatology Product contains monthly global climatology gridded (0.5 x 0.5 deg) data derived from SeaWiFS Deep Blue Level 3...

  4. SeaWiFS Deep Blue Aerosol Optical Depth and Angstrom Exponent Monthly Level 3 Data Gridded at 0.5 Degrees V004

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS Deep Blue Level 3 Monthly Product contains monthly global gridded (0.5 x 0.5 deg) data derived from SeaWiFS Deep Blue Level 3 daily gridded data. The...

  5. SeaWiFS Deep Blue Aerosol Optical Depth and Angstrom Exponent Monthly Level 3 Data Gridded at 1.0 Degrees V004

    Data.gov (United States)

    National Aeronautics and Space Administration — The SeaWiFS Deep Blue Level 3 Monthly Product contains monthly global gridded (1 x 1 deg) data derived from SeaWiFS Deep Blue Level 3 daily gridded data. The primary...

  6. Breath-hold MR imaging of focal hepatic lesions : clinical usefulness of breath-hold TSE T2WI combined by fast low-angle shot (FLASH) MR imaging

    International Nuclear Information System (INIS)

    Kim, Tae Hoon; Kim, Ki Whang; Kim, Eun Kyung; Yu, Jeong Sik

    1996-01-01

    To compare the image quality and diagnostic efficacy of turbo spin-echo (TSE) T2WI with breath-hold turbo SE T2WI and to evaluate the clinical usefulness combined breath-hold turbo SE T2WI with FLASH (fast low-angle shot) MR imaging for the evaluation of focal hepatic lesions. A total of 47 patients with known or suspected hepatic mass were prospectively evaluated using a commercially available 1.5-T MR system. All patients were examined with conventional spin-echo T1WI, TSE T2WI, breath-hold TSE T2WI, and T1-Weighted FLASH with and without Gd-DTPA. The images were compared quantitatively (liver-lesion C/N ; CNR [contrast-to-noise ratio] and lesion detectability) and qualitatively (sharpness of anatomic structure, artifact, and overall image quality). A total 69 hepatic lesions were detected in 47 patients. Sixty-seven lesions (97.1%) were detected with Gd-FLASH, 66 (95.7%) with TSE T2WI, 65 (94.2%) with breath-hold TSE T2WI, 62 (89.9%) with non-enhanced FLASH, and 55 (79.7%) with conventional SE T1WI. The CNR of cysts and hemangiomas was significantly greater on turbo SE T2WI and breath-hold TSE T2WI than on other sequences, but there was no significant difference between turbo SE T2WI and breath-hold TSE T2WI. For solid lesions, CNR was greatest on turbo SE T2WI and was similar on breath-hold TSE T2WI and Gd-FLASH without statistical significance, but was significantly higher than conventional SE T1WI. Breath-hold TSE T2WI and Gd-FLASH were qualitatively superior to other sequences except the vascular pulsation artifact of FLASH. Non-enhanced FLASH was also superior to conventional T1WI for CNR, lesion detectability, sharpness, respiratory motion artifact, and overall image quality. Breath-hold TSE T2WI may replace turbo SE T2WI, and as well as conventional SE T1WI, FLASH with or without Gd-DTPA may be used for the evaluation of focal hepatic lesions. The combination of FLASH and breath-hold TSE T2WI may be an excellent technique that can be used to rapidly

  7. Multiple sclerosis: patient-reported quality of life in the Świętokrzyskie Region

    Directory of Open Access Journals (Sweden)

    Waldemar Brola

    2017-09-01

    Full Text Available Introduction : Comprehensive epidemiologic data for multiple sclerosis (MS in Poland are limited. Aim of the research: To analyse patient-reported quality of life and selected clinical and socio-demographic factors of patients registered in the Świętokrzyskie Cohort of the Polish Registry of Multiple Sclerosis (RejSM. Material and methods: Participants were residents of Świętokrzyskie Province, and the data were collected between January 1st 2014 and December 31st 2015 by the RejSM web portal. After registration by doctors, the respondents assessed their quality of life individually using the Polish language versions of self-assessment questionnaires, the EuroQol (EQ-5D and EQ-VAS, and the Multiple Sclerosis Impact Scale (MSIS-29. Results : Of 1525 registered patients, 765 agreed to perform self-assessments of life quality and were included in the study. The mean degree of disability measured with the Expanded Disability Status Scale (EDSS was 3.8 ±2.3. The mean EQ-5D index score was 0.78 ±0.28, and the mean EQ-VAS score was 65.6 ±23.8. Assessment score with MSIS-29 averaged 86.4 ±22.4 (64.2 ±19.6 for physical state and 24.7 ±7.8 for mental state. Only 34.7% of respondents were economically active. Lower quality of life was significantly associated with higher disability scores (p < 0.001, age over 40 years (p < 0.001, longer disease duration (p < 0.001, no access to therapy (p < 0.001, and unemployment (p = 0.002. No correlation was found between life quality and sex, course of disease, level of education, place of residence, or family status. Conclusions: The main factors decreasing life quality among patients in Świętokrzyskie Province are advanced disability, old age, long disease duration, and limited access to both employment and immunomodulatory treatment.

  8. Wi-GIM system: a new wireless sensor network (WSN) for accurate ground instability monitoring

    Science.gov (United States)

    Mucchi, Lorenzo; Trippi, Federico; Schina, Rosa; Fornaciai, Alessandro; Gigli, Giovanni; Nannipieri, Luca; Favalli, Massimiliano; Marturia Alavedra, Jordi; Intrieri, Emanuele; Agostini, Andrea; Carnevale, Ennio; Bertolini, Giovanni; Pizziolo, Marco; Casagli, Nicola

    2016-04-01

    Landslides are among the most serious and common geologic hazards around the world. Their impact on human life is expected to increase in the next future as a consequence of human-induced climate change as well as the population growth in proximity of unstable slopes. Therefore, developing better performing technologies for monitoring landslides and providing local authorities with new instruments able to help them in the decision making process, is becoming more and more important. The recent progresses in Information and Communication Technologies (ICT) allow us to extend the use of wireless technologies in landslide monitoring. In particular, the developments in electronics components have permitted to lower the price of the sensors and, at the same time, to actuate more efficient wireless communications. In this work we present a new wireless sensor network (WSN) system, designed and developed for landslide monitoring in the framework of EU Wireless Sensor Network for Ground Instability Monitoring - Wi-GIM project (LIFE12 ENV/IT/001033). We show the preliminary performance of the Wi-GIM system after the first period of monitoring on the active Roncovetro Landslide and on a large subsiding area in the neighbourhood of Sallent village. The Roncovetro landslide is located in the province of Reggio Emilia (Italy) and moved an inferred volume of about 3 million cubic meters. Sallent village is located at the centre of the Catalan evaporitic basin in Spain. The Wi-GIM WSN monitoring system consists of three levels: 1) Master/Gateway level coordinates the WSN and performs data aggregation and local storage; 2) Master/Server level takes care of acquiring and storing data on a remote server; 3) Nodes level that is based on a mesh of peripheral nodes, each consisting in a sensor board equipped with sensors and wireless module. The nodes are located in the landslide ground perimeter and are able to create an ad-hoc WSN. The location of each sensor on the ground is

  9. Chlorophyll-a, Orbview-2 SeaWiFS, 0.04167 degrees, West US, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NASA GSFC Ocean Color Web distributes science-quality chlorophyll-a concentration data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the Orbview-2...

  10. Resource management framework for QoS scheduling in IEEE 802.16 WiMAX networks

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2009-01-01

    IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays...

  11. A Routing Algorithm for WiFi-Based Wireless Sensor Network and the Application in Automatic Meter Reading

    Directory of Open Access Journals (Sweden)

    Li Li

    2013-01-01

    Full Text Available The Automatic Meter Reading (AMR network for the next generation Smart Grid is required to possess many essential functions, such as data reading and writing, intelligent power transmission, and line damage detection. However, the traditional AMR network cannot meet the previous requirement. With the development of the WiFi sensor node in the low power cost, a new kind of wireless sensor network based on the WiFi technology can be used in application. In this paper, we have designed a new architecture of WiFi-based wireless sensor network, which is suitable for the next generation AMR system. We have also proposed a new routing algorithm called Energy Saving-Based Hybrid Wireless Mesh Protocol (E-HWMP on the premise of current algorithm, which can improve the energy saving of the HWMP and be suitable for the WiFi-based wireless sensor network. The simulation results show that the life cycle of network is extended.

  12. Extended Kalman Filter for Real Time Indoor Localization by Fusing WiFi and Smartphone Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Zhi-An Deng

    2015-04-01

    Full Text Available Indoor localization systems using WiFi received signal strength (RSS or pedestrian dead reckoning (PDR both have their limitations, such as the RSS fluctuation and the accumulative error of PDR. To exploit their complementary strengths, most existing approaches fuse both systems by a particle filter. However, the particle filter is unsuitable for real time localization on resource-limited smartphones, since it is rather time-consuming and computationally expensive. On the other hand, the light computation fusion approaches including Kalman filter and its variants are inapplicable, since an explicit RSS-location measurement equation and the related noise statistics are unavailable. This paper proposes a novel data fusion framework by using an extended Kalman filter (EKF to integrate WiFi localization with PDR. To make EKF applicable, we develop a measurement model based on kernel density estimation, which enables accurate WiFi localization and adaptive measurement noise statistics estimation. For the PDR system, we design another EKF based on quaternions for heading estimation by fusing gyroscopes and accelerometers. Experimental results show that the proposed EKF based data fusion approach achieves significant localization accuracy improvement over using WiFi localization or PDR systems alone. Compared with a particle filter, the proposed approach achieves comparable localization accuracy, while it incurs much less computational complexity.

  13. 76 FR 58032 - Notice of Intent To Repatriate a Cultural Item: State Historical Society of Wisconsin, Madison, WI

    Science.gov (United States)

    2011-09-19

    ... shared group identity that can be reasonably traced between the sacred object/object of cultural... Cultural Item: State Historical Society of Wisconsin, Madison, WI AGENCY: National Park Service, Interior... Indian Tribe, has determined a cultural item meets the definitions of sacred object and object of...

  14. 76 FR 62330 - Radio Broadcasting Services; Alamo, GA; Alton, MO; Boscobel, WI; Buffalo, OK; Cove, AR; Clayton...

    Science.gov (United States)

    2011-10-07

    ... Broadcasting Services; Alamo, GA; Alton, MO; Boscobel, WI; Buffalo, OK; Cove, AR; Clayton, LA; Daisy, AR; Ennis...) 418-2180. SUPPLEMENTARY INFORMATION: This is a synopsis of the Commission's Notice of Proposed Rule... FCC's Reference Information Center at Portals II, CY-A257, 445 Twelfth Street, SW., Washington, DC...

  15. Integrated WiFi/PDR/Smartphone Using an Adaptive System Noise Extended Kalman Filter Algorithm for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Xin Li

    2016-02-01

    Full Text Available Wireless signal strength is susceptible to the phenomena of interference, jumping, and instability, which often appear in the positioning results based on Wi-Fi field strength fingerprint database technology for indoor positioning. Therefore, a Wi-Fi and PDR (pedestrian dead reckoning real-time fusion scheme is proposed in this paper to perform fusing calculation by adaptively determining the dynamic noise of a filtering system according to pedestrian movement (straight or turning, which can effectively restrain the jumping or accumulation phenomena of wireless positioning and the PDR error accumulation problem. Wi-Fi fingerprint matching typically requires a quite high computational burden: To reduce the computational complexity of this step, the affinity propagation clustering algorithm is adopted to cluster the fingerprint database and integrate the information of the position domain and signal domain of respective points. An experiment performed in a fourth-floor corridor at the School of Environment and Spatial Informatics, China University of Mining and Technology, shows that the traverse points of the clustered positioning system decrease by 65%–80%, which greatly improves the time efficiency. In terms of positioning accuracy, the average error is 4.09 m through the Wi-Fi positioning method. However, the positioning error can be reduced to 2.32 m after integration of the PDR algorithm with the adaptive noise extended Kalman filter (EKF.

  16. Emergency preparedness for power outages and wi-fi loss: tips for students and educators of online courses.

    Science.gov (United States)

    Heithaus, Teresa

    2015-01-01

    Severe weather can impact online education due to a loss of power and Internet access that can last hours or weeks. Planning for such losses is essential to enable participation in the online classroom. This article discusses measures that can be used to maintain an online presence in the event of a power outage or loss of Wi-Fi. Copyright 2015, SLACK Incorporated.

  17. Realistic Indoor Wi-Fi and Femto deployment Study as the Offloading Solutions to LTE Macro Network

    DEFF Research Database (Denmark)

    Hu, Liang; Coletti, Claudio; Nguyen, Huan Cong

    2012-01-01

    -carrier macro network will suffer high network outage which is defined as proportion of outage users. A user is considered to be in outage if they have a user throughput less than 1 Mbps. We evaluate the performance of indoor Wi-Fi and Femto cell deployment to offload the congested LTE macro network. We show...

  18. An Improved WiFi/PDR Integrated System Using an Adaptive and Robust Filter for Indoor Localization

    Directory of Open Access Journals (Sweden)

    Zengke Li

    2016-11-01

    Full Text Available Location-based services (LBS are services offered through a mobile device that take into account a device’s geographical location. To provide position information for these services, location is a key process. GNSS (Global Navigation Satellite System can provide sub-meter accuracy in open-sky areas using satellite signals. However, for indoor and dense urban environments, the accuracy deteriorates significantly because of weak signals and dense multipaths. The situation becomes worse in indoor environments where the GNSS signals are unreliable or totally blocked. To improve the accuracy of indoor positioning for location-based services, an improved WiFi/Pedestrian Dead Reckoning (PDR integrated positioning and navigation system using an adaptive and robust filter is presented. The adaptive filter is based on scenario and motion state recognition and the robust filter is based on the Mahalanobis distance. They are combined and used in the WiFi/PDR integrated system to weaken the effect of gross errors on the dynamic and observation models. To validate their performance in the WiFi/PDR integrated system, a real indoor localization experiment is conducted. The results indicate that the adaptive filter is better able to adapt to the circumstances of the dynamic model by adjusting the covariance of the process noise and the robust Kalman filter is able to mitigate the harmful effect of gross errors from the WiFi positioning.

  19. Smartphone-Based Indoor Integrated WiFi/MEMS Positioning Algorithm in a Multi-Floor Environment

    Directory of Open Access Journals (Sweden)

    Zengshan Tian

    2015-03-01

    Full Text Available Indoor positioning in a multi-floor environment by using a smartphone is considered in this paper. The positioning accuracy and robustness of WiFi fingerprinting-based positioning are limited due to the unexpected variation of WiFi measurements between floors. On this basis, we propose a novel smartphone-based integrated WiFi/MEMS positioning algorithm based on the robust extended Kalman filter (EKF. The proposed algorithm first relies on the gait detection approach and quaternion algorithm to estimate the velocity and heading angles of the target. Second, the velocity and heading angles, together with the results of WiFi fingerprinting-based positioning, are considered as the input of the robust EKF for the sake of conducting two-dimensional (2D positioning. Third, the proposed algorithm calculates the height of the target by using the real-time recorded barometer and geographic data. Finally, the experimental results show that the proposed algorithm achieves the positioning accuracy with root mean square errors (RMSEs less than 1 m in an actual multi-floor environment.

  20. Det-WiFi: A Multihop TDMA MAC Implementation for Industrial Deterministic Applications Based on Commodity 802.11 Hardware

    Directory of Open Access Journals (Sweden)

    Yujun Cheng

    2017-01-01

    Full Text Available Wireless control system for industrial automation has been gaining increasing popularity in recent years thanks to their ease of deployment and the low cost of their components. However, traditional low sample rate industrial wireless sensor networks cannot support high-speed application, while high-speed IEEE 802.11 networks are not designed for real-time application and not able to provide deterministic feature. Thus, in this paper, we propose Det-WiFi, a real-time TDMA MAC implementation for high-speed multihop industrial application. It is able to support high-speed applications and provide deterministic network features since it combines the advantages of high-speed IEEE802.11 physical layer and a software Time Division Multiple Access (TDMA based MAC layer. We implement Det-WiFi on commercial off-the-shelf hardware and compare the deterministic performance between 802.11s and Det-WiFi under the real industrial environment, which is full of field devices and industrial equipment. We changed the hop number and the packet payload size in each experiment, and all of the results show that Det-WiFi has better deterministic performance.

  1. Wi-Fi Walkman : A wireless handhold that shares and recommends music on peer-to-peer networks

    NARCIS (Netherlands)

    Wang, J.; Reinders, M.J.T.; Pouwelse, J.; Lagendijk, R.L.

    2005-01-01

    The Wi-Fi walkman is a mobile multimedia application that we developed to investigate the technological and usability aspects of human-computer interaction with personalized, intelligent and context-aware wearable devices in peer-to-peer wireless environments such as the future home, office, or

  2. Crowd-Sourced Mobility Mapping for Location Tracking Using Unlabeled Wi-Fi Simultaneous Localization and Mapping

    Directory of Open Access Journals (Sweden)

    Mu Zhou

    2015-01-01

    Full Text Available Due to the increasing requirements of the seamless and round-the-clock Location-based services (LBSs, a growing interest in Wi-Fi network aided location tracking is witnessed in the past decade. One of the significant problems of the conventional Wi-Fi location tracking approaches based on received signal strength (RSS fingerprinting is the time-consuming and labor intensive work involved in location fingerprint calibration. To solve this problem, a novel unlabeled Wi-Fi simultaneous localization and mapping (SLAM approach is developed to avoid the location fingerprinting and additional inertial or vision sensors. In this approach, an unlabeled mobility map of the coverage area is first constructed by using the crowd-sourcing from a batch of sporadically recorded Wi-Fi RSS sequences based on the spectral cluster assembling. Then, the sequence alignment algorithm is applied to conduct location tracking and mobility map updating. Finally, the effectiveness of this approach is verified by the extensive experiments carried out in a campus-wide area.

  3. Impact of meteorological conditions on stability of selected slopes in the Wiśnicz Foothills

    Directory of Open Access Journals (Sweden)

    Demczuk Piotr

    2014-12-01

    Full Text Available Wpływ warunków meteorologicznych na kształtowanie się warunków stateczności wybranych zboczy Pogórza Wiśnickiego. Jednym z najważniejszych procesów wpływających na kształtowanie stoków górskich zbudowanych z fl iszu karpackiego są ruchy masowe. Tylko na nielicznych obiektach prowadzono kompleksowe, pogłębione badania mechanizmów inicjacji ruchów osuwiskowych. Badania takowe są czasochłonne, a zadowalające i wiarygodne wyniki osiąga się po co najmniej kilkuletnim okresie pomiarów i analiz. Większość programów badań ogranicza się do krótkich, jednorazowych obserwacji i pomiarów powierzchniowych. Uwaga uczestników tych projektów skupia się na dużych osuwiskach strukturalnych obejmujących swoim zasięgiem głęboko zalegające skały trzeciorzędowe, pomijając płytkie osuwiska zachodzące na granicy zwietrzeliny i skał litych oraz w zasięgu samej zwietrzeliny. Celem pracy było określenie przebiegu zmian warunków stateczności wybranych zboczy związanych ze warunkami meteorologicznych występujących w latach 2008-2013 na obszarze Pogórza Wiśnickiego. Dla potrzeb pracy wykorzystano dane meteorologiczne, tj. temperatura powietrza, wilgotność gleby, prędkość wiatru, sumy opadów i liczba dni z deszczem, pochodzące ze Stacji Naukowej IGiGP UJ w Łazach koło Bochni (Pogórze Wiśnickie. Przeprowadzono terenowe i laboratoryjne badania parametrów geotechnicznych gruntów stanowiących pokrywy stokowe wybranych zboczy osuwiskowych we wsiach Królówka i Łychówo. Wcześniej wspomiane dane meteorologiczne, a także dane dotyczące temperatury, wilgotności względnej powietrza wykorzystano w dalszej części pracy do określenia zmian stanu naprężeń dla dwóch zboczy osuwiskowych. W tym celu zastosowano moduły Slope/W, Vados/W oraz Seep/W stanowiące część pakietu GeoSlope. Wyniki analiz potwierdziły, że stabilność zbocza jest silnie związana z opadami atmosferycznymi, ale wykazały r

  4. A compact ultra wideband antenna with WiMax band rejection for energy scavenging

    International Nuclear Information System (INIS)

    Jalil, Y E; Chakrabarty, C K; Kasi, B

    2013-01-01

    Radio Frequency (RF) energy harvesting has been rapidly advancing as a promising alternative to existing energy scavenging system. A well designed broadband antenna such as ultra-wideband (UWB) antenna can be used as one of the major components in an RF energy scavenging system. This paper presents a compact UWB antenna showing good impedance matching over a bandwidth of 2.8 to 11 GHz, suiTable for broadband RF energy scavenging. Nevertheless, the antenna usage in wireless communication has a limitation due to the problem of interference between UWB system and other narrowband systems. Thus, the proposed antenna is successfully designed with a single band-notched at the targeted WiMAX operating band of 3.3 to 3.6 GHz.

  5. Spectrum sharing between a surveillance radar and secondary Wi-Fi networks

    Science.gov (United States)

    Hessar, Farzad; Roy, Sumit

    2016-06-01

    Co-existence between unlicensed networks that share spectrum spatio-temporally with terrestrial (e.g. Air Traffic Control) and shipborne radars in 3-GHz band is attracting significant interest. Similar to every primary-secondary coexistence scenario, interference from unlicensed devices to a primary receiver must be within acceptable bounds. In this work, we formulate the spectrum sharing problem between a pulsed, search radar (primary) and 802.11 WLAN as the secondary. We compute the protection region for such a search radar for a) a single secondary user (initially) as well as b) a random spatial distribution of multiple secondary users. Furthermore, we also analyze the interference to the WiFi devices from the radar's transmissions to estimate the impact on achievable WLAN throughput as a function of distance to the primary radar.

  6. Exploitation of Ubiquitous Wi-Fi Devices as Building Blocks for Improvised Motion Detection Systems.

    Science.gov (United States)

    Soldovieri, Francesco; Gennarelli, Gianluca

    2016-02-27

    This article deals with a feasibility study on the detection of human movements in indoor scenarios based on radio signal strength variations. The sensing principle exploits the fact that the human body interacts with wireless signals, introducing variations of the radiowave fields due to shadowing and multipath phenomena. As a result, human motion can be inferred from fluctuations of radiowave power collected by a receiving terminal. In this paper, we investigate the potentialities of widely available wireless communication devices in order to develop an improvised motion detection system (IMDS). Experimental tests are performed in an indoor environment by using a smartphone as a Wi-Fi access point and a laptop with dedicated software as a receiver. Simple detection strategies tailored for real-time operation are implemented to process the received signal strength measurements. The achieved results confirm the potentialities of the simple system here proposed to reliably detect human motion in operational conditions.

  7. An improved algorithm to generate a Wi-Fi fingerprint database for indoor positioning.

    Science.gov (United States)

    Chen, Lina; Li, Binghao; Zhao, Kai; Rizos, Chris; Zheng, Zhengqi

    2013-08-21

    The major problem of Wi-Fi fingerprint-based positioning technology is the signal strength fingerprint database creation and maintenance. The significant temporal variation of received signal strength (RSS) is the main factor responsible for the positioning error. A probabilistic approach can be used, but the RSS distribution is required. The Gaussian distribution or an empirically-derived distribution (histogram) is typically used. However, these distributions are either not always correct or require a large amount of data for each reference point. Double peaks of the RSS distribution have been observed in experiments at some reference points. In this paper a new algorithm based on an improved double-peak Gaussian distribution is proposed. Kurtosis testing is used to decide if this new distribution, or the normal Gaussian distribution, should be applied. Test results show that the proposed algorithm can significantly improve the positioning accuracy, as well as reduce the workload of the off-line data training phase.

  8. Wi-Fi technology--an uncontrolled global experiment on the health of mankind.

    Science.gov (United States)

    Markov, Marko; Grigoriev, Yuri G

    2013-06-01

    The twenty-first century is marked with exponentially increasing development of technologies that provide wireless communications. To the pollution of the atmosphere with radio and TV signals, not only satellite communications but also any varieties of the Wi-Fi networks are added. By 2010 in the USA, 285 million mobile phone subscribers have been registered (for a little bit more than 300 million inhabitants). The estimate for the world is more than 5 billion mobile phone users at approximately 7 billion people living on this planet. Approximately 2 years ago, the International Agency of Research on Cancer (IARC) classified the electromagnetic fields used in mobile communication as a possible cancerogene. This paper discusses the potential health hazard and lack of scientific assessment and regulatory actions in protection of the life on the planet.

  9. Design and Development of a Portable WiFi enabled BIA device

    International Nuclear Information System (INIS)

    Kriz'aj, D; Baloh, M; Zagar, T; Brajkovic, R

    2013-01-01

    A bioimpedance device (BIA) for evaluation of sarcopenia – age related muscle mass loss – is designed, developed and evaluated. The requirements were based on lightweight design, flexible and user enabled incorporation of measurement protocols and WiFi protocol for remote device control, full internet integration and fast development and usage of measurement protocols. The current design is based on usage of a microcontroller with integrated AD/DA converters. The prototype system was assembled and the operation and connectivity to different handheld devices and laptop computers was successfully tested. The designed BIA device can be accessed using TCP sockets and once the connection is established the data transfer runs successfully at the specified speed. The accuracy of currently developed prototype is about 5% for the impedance modulus and 5 deg. for the phase for the frequencies below 20 kHz with an unfiltered excitation signal and no additional amplifiers employed.

  10. Brain MRI findings of welders : high signal intensity in T1WI secondary to manganese exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. W.; Lim, M. A.; Shon, M. Y.; Lee, S. H.; Ha, D. G.; Kwon, K. R.; Kim, S. S.; Hong, Y. S.; Lee, Y. H. [Sunlin Presbyterian Hospital, Pohang (Korea, Republic of); Cheong, H. K. [Dongguk University, Seoul (Korea, Republic of)

    1998-03-01

    To evaluate the clinical and brain MRI findings of welders and to determine the utility of MRI in the assessment of occupational manganese exposure. All welders complained of fatigue, headache, anorexia, and decreased libido. The palmomental reflex was positive in five (28%), Myerson`s sign in four (22%), and intention tremor in three (17%). Mean blood Mn was 5.18 (range, 1.77-9.34) {mu}g/dl, mean urine Mn was 5.84 (range, 1.07 -22) {mu}g/l, serum Fe was elevated in one welder, and serum Cd in two. T1WI of brain MRI revealed high signal intensities in the globus pallidus, the putamen, the substantia nigra, the tectum, the caudate nucleus, the subthalamic nucleus, the hypothalamus and the pituitary gland. These intensities correlated closely with blood Mn levels, suggesting their potential role in estimating the accumulation of Mn in the brain. (author). 25 refs., 2 tabs., 5 figs.

  11. Semantic wireless localization of WiFi terminals in smart buildings

    Science.gov (United States)

    Ahmadi, H.; Polo, A.; Moriyama, T.; Salucci, M.; Viani, F.

    2016-06-01

    The wireless localization of mobile terminals in indoor scenarios by means of a semantic interpretation of the environment is addressed in this work. A training-less approach based on the real-time calibration of a simple path loss model is proposed which combines (i) the received signal strength information measured by the wireless terminal and (ii) the topological features of the localization domain. A customized evolutionary optimization technique has been designed to estimate the optimal target position that fits the complex wireless indoor propagation and the semantic target-environment relation, as well. The proposed approach is experimentally validated in a real building area where the available WiFi network is opportunistically exploited for data collection. The presented results point out a reduction of the localization error obtained with the introduction of a very simple semantic interpretation of the considered scenario.

  12. Proteome oxidative carbonylation during oxidative stress-induced premature senescence of WI-38 human fibroblasts

    DEFF Research Database (Denmark)

    Le Boulch, Marine; Ahmed, Emad K; Rogowska-Wrzesinska, Adelina

    2018-01-01

    Accumulation of oxidatively damaged proteins is a hallmark of cellular and organismal ageing, and is also a phenotypic feature shared by both replicative senescence and stress-induced premature senescence of human fibroblasts. Moreover, proteins that are building up as oxidized (i.e. the "Oxi......-proteome") during ageing and age-related diseases represent a restricted set of cellular proteins, indicating that certain proteins are more prone to oxidative carbonylation and subsequent intracellular accumulation. The occurrence of specific carbonylated proteins upon oxidative stress induced premature senescence...... of WI-38 human fibroblasts and their follow-up identification have been addressed in this study. Indeed, it was expected that the identification of these proteins would give insights into the mechanisms by which oxidatively damaged proteins could affect cellular function. Among these proteins, some...

  13. Simulasi dan Analisis Transmisi Multihop Mobile WiMAX Dengan Metode Hybrid

    Directory of Open Access Journals (Sweden)

    Muhamad Asvial

    2016-06-01

    Full Text Available Makalah ini membahas tentang pengembangan relay station untuk transmisi downlink Mobile WiMAX dengan menggunakan metode hybrid, yaitu metode transmisi yang menggunakan tiga buah transmisi. Ketiga transmisi tersebut yaitu dua buah transmisi yang melewati relay station terlebih dahulu baru ke receiver dan satu buah transmisi langsung dari pengirim ke penerima. Pada relay station ada dua kondisi yang berlaku, yaitu Decode and Forward (DF dan Amplify and Forward (AF. Hasil simulasi menunjukkan bahwa ketika Relay Station dalam mode forwarding Amplify and Forward (AF akan memperoleh BER yang kecil sehingga throughput besar dan merupakan perfomansi yang terbaik. Ketika masing-masing relay station diatur agar menggunakan mode forwarding yang berbeda, misalnya AF pada relay station 1 dan DF pada Relay Station 2 atau sebaliknya akan memperoleh hasil yang sama. Sedangkan ketika kedua relay station diatur untuk menggunakan mode forwarding Decode and Forward (DF, maka BER yang dihasilkan besar dan throughput-nya pun kecil, dan kondisi ini merupakan yang terburuk.

  14. High Current, High Density Arc Plasma as a New Source for WiPAL

    Science.gov (United States)

    Waleffe, Roger; Endrizzi, Doug; Myers, Rachel; Wallace, John; Clark, Mike; Forest, Cary; WiPAL Team

    2016-10-01

    The Wisconsin Plasma Astrophysics Lab (WiPAL) has installed a new array of nineteen plasma sources (plasma guns) on its 3 m diameter, spherical vacuum vessel. Each gun is a cylindrical, molybdenum, washer-stabilized, arc plasma source. During discharge, the guns are maintained at 1.2 kA across 100 V for 10 ms by the gun power supply establishing a high density plasma. Each plasma source is fired independently allowing for adjustable plasma parameters, with densities varying between 1018 -1019 m-3 and electron temperatures of 5-15 eV. Measurements were characterized using a 16 tip Langmuir probe. The plasma source will be used as a background plasma for the magnetized coaxial plasma gun (MCPG), the Terrestrial Reconnection Experiment (TREX), and as the plasma source for a magnetic mirror experiment. Temperature, density, and confinement results will be presented. This work is supported by the DoE and the NSF.

  15. Driven-Walking for Visually Impaired/Blind People through WiMAX

    Directory of Open Access Journals (Sweden)

    Panagiotis GIOANNIS

    2010-03-01

    Full Text Available It is known that people who are blind/visually impaired find it difficult to move, especially in unknown places. Usually the only help they have is their walking stick (white cane, a guide dog and sometimes special warning sounds or road signals at specific positions. Material and Method: In this paper we are trying to find a solution on how to build an appropriate navigating system for blind people. Results: Based on benefits of powerful properties of mobile WiMAX standard we suggest an important navigate application which can translate a digital visual environment properly for blind/visually impaired users through a plethora of combinations such as voice, brain or tongue signals. Conclusions: We believe that such an idea will be an initial point for a plethora of applications which will eliminate walking disabilities of blind/visually people.

  16. Interplay between Selenium Levels and Replicative Senescence in WI-38 Human Fibroblasts: A Proteomic Approach

    Directory of Open Access Journals (Sweden)

    Ghania Hammad

    2018-01-01

    Full Text Available Selenoproteins are essential components of antioxidant defense, redox homeostasis, and cell signaling in mammals, where selenium is found in the form of a rare amino acid, selenocysteine. Selenium, which is often limited both in food intake and cell culture media, is a strong regulator of selenoprotein expression and selenoenzyme activity. Aging is a slow, complex, and multifactorial process, resulting in a gradual and irreversible decline of various functions of the body. Several cellular aspects of organismal aging are recapitulated in the replicative senescence of cultured human diploid fibroblasts, such as embryonic lung fibroblast WI-38 cells. We previously reported that the long-term growth of young WI-38 cells with high (supplemented, moderate (control, or low (depleted concentrations of selenium in the culture medium impacts their replicative lifespan, due to rapid changes in replicative senescence-associated markers and signaling pathways. In order to gain insight into the molecular link between selenium levels and replicative senescence, in the present work, we have applied a quantitative proteomic approach based on 2-Dimensional Differential in-Gel Electrophoresis (2D-DIGE to the study of young and presenescent cells grown in selenium-supplemented, control, or depleted media. Applying a restrictive cut-off (spot intensity ±50% and a p value < 0.05 to the 2D-DIGE analyses revealed 81 differentially expressed protein spots, from which 123 proteins of interest were identified by mass spectrometry. We compared the changes in protein abundance for three different conditions: (i spots varying between young and presenescent cells, (ii spots varying in response to selenium concentration in young cells, and (iii spots varying in response to selenium concentration in presenescent cells. Interestingly, a 72% overlap between the impact of senescence and selenium was observed in our proteomic results, demonstrating a strong interplay between

  17. Fire Extinguisher Robot Using Ultrasonic Camera and Wi-Fi Network Controlled with Android Smartphone

    Science.gov (United States)

    Siregar, B.; Purba, H. A.; Efendi, S.; Fahmi, F.

    2017-03-01

    Fire disasters can occur anytime and result in high losses. It is often that fire fighters cannot access the source of fire due to the damage of building and very high temperature, or even due to the presence of explosive materials. With such constraints and high risk in the handling of the fire, a technological breakthrough that can help fighting the fire is necessary. Our paper proposed the use of robots to extinguish the fire that can be controlled from a specified distance in order to reduce the risk. A fire extinguisher robot was assembled with the intention to extinguish the fire by using a water pump as actuators. The robot movement was controlled using Android smartphones via Wi-fi networks utilizing Wi-fi module contained in the robot. User commands were sent to the microcontroller on the robot and then translated into robotic movement. We used ATMega8 as main microcontroller in the robot. The robot was equipped with cameras and ultrasonic sensors. The camera played role in giving feedback to user and in finding the source of fire. Ultrasonic sensors were used to avoid collisions during movement. Feedback provided by camera on the robot displayed on a screen of smartphone. In lab, testing environment the robot can move following the user command such as turn right, turn left, forward and backward. The ultrasonic sensors worked well that the robot can be stopped at a distance of less than 15 cm. In the fire test, the robot can perform the task properly to extinguish the fire.

  18. Discovering the Azores front/current system with SeaWiFS imagery

    Science.gov (United States)

    Martins, Ana M.; Bashmachnikov, Igor L.; Lafon, Virginie M.; Mendonca, Ana H.; Jose, Felix; Figueiredo, Miguel P.; Macedo, Luis M.

    2004-11-01

    Ocean Colour (OC) sensors have been primarily used in biological studies. More recently, OC information has been attracting the attention of oceanographers, as a potential method for revealing physical structures in the ocean. In this study, OC data obtained from SeaWiFS imagery is used, for the first time, to detect the weak Azores Current (AzC) and the associated Azores Front (AzF). Previous studies show that the frontal interface is well seen on SST imagery only during the cold season, while it is disguised during the warm season through the formation of a strong seasonal thermocline. With SeaWiFS imagery, the frontal interface is well identified around 34° N as an asymmetric zonally stretched band of higher near-surface chlorophyll a (CHL a) values north of the AzF, accompanied by a sharp decrease to the south. Quasi-stationary meanders, previously derived from SST fields for the same region, are also well observed in OC imagery. Monthly-averaged Chl a along a meridional cross-section shows that, from spring to autumn, the front is clearly visible. In winter, differences across the front are less pronounced, and the front is more easily identified on SST fields. OC gradients weaken to the east, corresponding to the general weakening of the AzC. In situ CTD data reveal a sharp and meandering thermohaline and dissolved oxygen front ocated at 33-34.5° N and 31° W. This study suggests that OC imagery, combined with other sensors, provide an important tool to investigate ocean dynamic variability, by helping to detect frontal zones with great precision.

  19. Lactobacillus curvatus WiKim38 isolated from kimchi induces IL-10 production in dendritic cells and alleviates DSS-induced colitis in mice.

    Science.gov (United States)

    Jo, Sung-Gang; Noh, Eui-Jeong; Lee, Jun-Young; Kim, Green; Choi, Joo-Hee; Lee, Mo-Eun; Song, Jung-Hee; Chang, Ji-Yoon; Park, Jong-Hwan

    2016-07-01

    Probiotics such as lactobacilli and bifidobacteria have healthpromoting effects by immune modulation. In the present study, we examined the immunomodulatory properties of Lactobacillus curvatus WiKim38, which was newly isolated from baechu (Chinese cabbage) kimchi. The ability of L. curvatus WiKim38 to induce cytokine production in bone marrow-derived dendritic cells (BMDCs) was determined by enzyme-linked immunosorbent assay. To evaluate the molecular mechanisms underlying L. curvatus Wikim38-mediated IL-10 production, Western blot analyses and inhibitor assays were performed. Moreover, the in vivo anti-inflammatory effects of L. curvatus WiKim38 were examined in a dextran sodium sulfate (DSS)-induced colitis mouse model. L. curvatus WiKim38 induced significantly higher levels of IL-10 in BMDCs compared with that induced by LPS. NF-κB and ERK were activated by L. curvatus WiKim38, and an inhibitor assay revealed that these pathways were required for L. curvatus WiKim38-induced production of IL-10 in BMDCs. An in vivo experiment showed that oral administration of L. curvatus WiKim38 increased the survival rate of mice with DSS-induced colitis and improved clinical signs and histopathological severity in colon tissues. Taken together, these results indicate that L. curvatus Wikim38 may have health-promoting effects via immune modulation, and may thus be applicable for therapy of various inflammatory diseases.

  20. Validity of a Wireless Gait Analysis Tool (Wi-GAT) in assessing spatio-temporal gait parameters at slow, preferred and fast walking speeds.

    Science.gov (United States)

    DesJardins, Ashley M; Schiller, Martha; Eraqi, Enas; Samuels, Amanda Nicole; Galen, Sujay S

    2016-11-14

    The wireless gait assessment tool (Wi-GAT) measures have been shown to have good to excellent concurrent validity with preferred walking speeds, however, the validity of the Wi-GAT measures at slow and fast walking speeds is unknown. To establish validity of the Wi-GAT spatio-temporal gait measures at slow, fast, and preferred walking speeds. Twenty two healthy adult volunteers, with a mean age of 25.7 (± 5.3) participated in this study. The spatio-temporal gait variables of each participant were concurrently recorded using the GAITrite and the Wi-GAT system, while the participants performed 3 trials for each walking speed in a randomized order. Intraclass correlation analyses were performed to establish the agreement between the measures recorded by the GAITrite and Wi-GAT systems. Walking speed measured both by the Wi-GAT and the GAITrite systems showed excellent agreement for preferred (ICC = 0.979 pgait parameters recorded at slow walking speed showed good (ICC > 0.70) to excellent (ICC > 0.85) agreement. Gait parameters recorded by the Wi-GAT system showed fair to excellent validity for preferred and slow walking speeds.

  1. The First SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-1)

    Science.gov (United States)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Claustre, Herve; Ras, Josephine; VanHeukelem, Laurie; Berthon, Jean-Francois; Targa, Cristina; vanderLinde, Dirk; Barlow, Ray; Sessions, Heather

    2001-01-01

    Four laboratories, which had contributed to various aspects of SeaWiFS calibration and validation activities, participated in the first SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-1): Horn Point Laboratory (USA), the Joint Research Centre (Italy), the Laboratoire de Physique et Chimie Marines (France), and the Marine and Coastal Management group (South Africa). The analyses of the data are presented in Chapter 1 and the individual methods of the four groups are presented in Chapters 2-5. The average (or overall) conclusions of the round-robin are derived from 12 in situ stations occupied during a cruise in the Mediterranean Sea, although, only 11 stations are used in the analyses. The data set is composed of 12 replicates taken during each sampling opportunity with 3 replicates going to each of the 4 laboratories. The average (or overall) results from the intercomparison of 15 pigments or pigment associations are as follows (in some cases, data subsets that exclude pigments which were not analyzed by all the laboratories, or that had unusually large variances, are used to exclude a variety of problematic pigments): a) the accuracy of the four methods in determining the concentration of total chlorophyll a is 7.9%, (one method did not separate mono- and divinyl chlorophyll a, and if the samples containing significant divinyl chlorophyll a concentrations are ignored, the four methods have an accuracy of 6.7%); b) the accuracy in determining the full set of pigments is 19.1%; c) there is a reduction in accuracy of approximately - 12.2% for every decade (factor of 10) decrease in concentration (based on a data subset); d) the precision of the four methods using a subset data is 8.617( 6.2% for an edited subset); e) the repeatability of the four methods using the subset data is 9.2% (7.2%; for an edited subset, and f) the reproducibility of the four methods using the subset data is 21.31% (15.0% for an edited subset).

  2. Resource management framework for QoS scheduling in IEEE 802.16 WiMAX networks

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2009-01-01

    IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays...... an important role in QoS provisioning for different types of services. In this chapter, we propose a downlink resource management framework for QoS scheduling in OFDMA based WiMAX systems. Our framework consists of a dynamic resource allocation (DRA) module and a connection admission control (CAC) module....... A two-level hierarchical scheduler is developed for the DRA module, which can provide more organized service differentiation among different service classes, and a measurement-based connection admission control strategy is introduced for the CAC module. Through system-level simulation, it is shown...

  3. Downlink resource management for QoS scheduling in IEEE 802.16 WiMAX networks

    DEFF Research Database (Denmark)

    Wang, Hua; Dittmann, Lars

    2010-01-01

    IEEE 802.16, also known as WiMAX, has received much attention recently for its capability to support multiple types of applications with diverse Quality-of-Service (QoS) requirements. Beyond what the standard has defined, radio resource management (RRM) still remains an open issue, which plays...... an important role in QoS provisioning for different types of services. In this paper, we propose a downlink resource management framework for QoS scheduling in OFDMA based WiMAX systems. Our framework consists of a dynamic resource allocation (DRA) module and a connection admission control (CAC) module. A two......-level hierarchical scheduler is developed for the DRA module, which can provide more organized service differentiation among different service classes, and a measurement-based connection admission control strategy is introduced for the CAC module. Through system-level simulation, it is shown that the proposed...

  4. A Rectangular Ring, Open-Ended Monopole Antenna with Two Symmetric Strips for WLAN and WiMAX Applications

    Directory of Open Access Journals (Sweden)

    Joong-Han Yoon

    2013-01-01

    Full Text Available A triple-band rectangular ring, open-ended monopole antenna with symmetric L strips for wireless local area network (WLAN/Worldwide Interoperability of Microwave Access (WiMAX applications is proposed. The proposed antenna consists of two symmetric folded arms and L strips. Based on the concept, a prototype of the proposed triple antenna has been designed, fabricated, and tested. The numerical and experimental results demonstrated that the proposed antenna satisfied the −10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. Furthermore, this paper presented and discussed the 2D radiation patterns and 3D gains according to the results of the experiment. The proposed antenna’s peak gain varied between 2.17 and 4.93 dBi, and its average gain varied between −2.97 and −0.53 dBi.

  5. Evaluation of electromagnetic interference and exposure assessment from s-health solutions based on Wi-Fi devices.

    Science.gov (United States)

    de Miguel-Bilbao, Silvia; Aguirre, Erik; Lopez Iturri, Peio; Azpilicueta, Leire; Roldán, José; Falcone, Francisco; Ramos, Victoria

    2015-01-01

    In the last decade the number of wireless devices operating at the frequency band of 2.4 GHz has increased in several settings, such as healthcare, occupational, and household. In this work, the emissions from Wi-Fi transceivers applicable to context aware scenarios are analyzed in terms of potential interference and assessment on exposure guideline compliance. Near field measurement results as well as deterministic simulation results on realistic indoor environments are presented, providing insight on the interaction between the Wi-Fi transceiver and implantable/body area network devices as well as other transceivers operating within an indoor environment, exhibiting topological and morphological complexity. By following approaches (near field estimation/deterministic estimation), colocated body situations as well as large indoor emissions can be determined. The results show in general compliance with exposure levels and the impact of overall network deployment, which can be optimized in order to reduce overall interference levels while maximizing system performance.

  6. A design of irregular grid map for large-scale Wi-Fi LAN fingerprint positioning systems.

    Science.gov (United States)

    Kim, Jae-Hoon; Min, Kyoung Sik; Yeo, Woon-Young

    2014-01-01

    The rapid growth of mobile communication and the proliferation of smartphones have drawn significant attention to location-based services (LBSs). One of the most important factors in the vitalization of LBSs is the accurate position estimation of a mobile device. The Wi-Fi positioning system (WPS) is a new positioning method that measures received signal strength indication (RSSI) data from all Wi-Fi access points (APs) and stores them in a large database as a form of radio fingerprint map. Because of the millions of APs in urban areas, radio fingerprints are seriously contaminated and confused. Moreover, the algorithmic advances for positioning face computational limitation. Therefore, we present a novel irregular grid structure and data analytics for efficient fingerprint map management. The usefulness of the proposed methodology is presented using the actual radio fingerprint measurements taken throughout Seoul, Korea.

  7. SeaWiFS technical report series. Volume 4: An analysis of GAC sampling algorithms. A case study

    Science.gov (United States)

    Yeh, Eueng-Nan (Editor); Hooker, Stanford B. (Editor); Hooker, Stanford B. (Editor); Mccain, Charles R. (Editor); Fu, Gary (Editor)

    1992-01-01

    The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument will sample at approximately a 1 km resolution at nadir which will be broadcast for reception by realtime ground stations. However, the global data set will be comprised of coarser four kilometer data which will be recorded and broadcast to the SeaWiFS Project for processing. Several algorithms for degrading the one kilometer data to four kilometer data are examined using imagery from the Coastal Zone Color Scanner (CZCS) in an effort to determine which algorithm would best preserve the statistical characteristics of the derived products generated from the one kilometer data. Of the algorithms tested, subsampling based on a fixed pixel within a 4 x 4 pixel array is judged to yield the most consistent results when compared to the one kilometer data products.

  8. The concentrations of trace metals in plants from phosphogypsum waste heap in Wiślinka, northern Poland

    Directory of Open Access Journals (Sweden)

    Boryło A.

    2013-04-01

    Full Text Available The aim of this work was determination of trace metals (Pb, Zn, Ni, Cu and Fe in different plants collected in the vicinity of phosphogypsum waste heap in Wiślinka (northern Poland. The concentrations of trace metals were determined by two methods: AAS (atomic absorption spectrometry and OES-ICP (atomic emission spectrometry with inductively coupled plasma. Enhanced levels of iron were observed in all the analyzed samples. This fact can be explained by the higher content of iron in the groundwaters of Žuławy Wiślane, where concentration of iron was 60 mg/l. The trace metals concentrations in plant samples from phosphogypsum waste heap recorded in this study are generally higher than in control sites. In this study the relationship is shown between atmospheric trace metals deposition and elevated trace metals element concentrations in plants and topsoils, especially in the vicinity of phoshpogypsum waste heap.

  9. Continuous Space Estimation: Increasing WiFi-Based Indoor Localization Resolution without Increasing the Site-Survey Effort †

    Science.gov (United States)

    Hernández, Noelia; Ocaña, Manuel; Alonso, Jose M.; Kim, Euntai

    2017-01-01

    Although much research has taken place in WiFi indoor localization systems, their accuracy can still be improved. When designing this kind of system, fingerprint-based methods are a common choice. The problem with fingerprint-based methods comes with the need of site surveying the environment, which is effort consuming. In this work, we propose an approach, based on support vector regression, to estimate the received signal strength at non-site-surveyed positions of the environment. Experiments, performed in a real environment, show that the proposed method could be used to improve the resolution of fingerprint-based indoor WiFi localization systems without increasing the site survey effort. PMID:28098773

  10. Continuous Space Estimation: Increasing WiFi-Based Indoor Localization Resolution without Increasing the Site-Survey Effort.

    Science.gov (United States)

    Hernández, Noelia; Ocaña, Manuel; Alonso, Jose M; Kim, Euntai

    2017-01-13

    Although much research has taken place in WiFi indoor localization systems, their accuracy can still be improved. When designing this kind of system, fingerprint-based methods are a common choice. The problem with fingerprint-based methods comes with the need of site surveying the environment, which is effort consuming. In this work, we propose an approach, based on support vector regression, to estimate the received signal strength at non-site-surveyed positions of the environment. Experiments, performed in a real environment, show that the proposed method could be used to improve the resolution of fingerprint-based indoor WiFi localization systems without increasing the site survey effort.

  11. A Comparison of the SeaWiFS Chlorophyll and CZCS Pigment Algorithms Using Optical Data From the 1992 JGOFS Equatorial Pacific Time Series

    National Research Council Canada - National Science Library

    Rhea, W. J; Davis, Curtiss O

    1997-01-01

    .... This data set represents the range of conditions expected in this region, and was used to compare the SeaWiFS chlorophyll alpha algorithm with the CZCS pigment algorithm, as well as test the validity...

  12. Analysis of bluetooth and wi-fi technology to measure wait times of personal vehicles at Arizona-Mexico ports of entry.

    Science.gov (United States)

    2015-11-01

    Robust travel time data collection is possible using Bluetooth or Wi-Fi technology that : matches anonymous MAC addresses from discoverable electronic devices (e.g., smart phones) : to determine travel time along a roadway segment. Several hundred...

  13. Electromagnetic radiation (Wi-Fi) and epilepsy induce calcium entry and apoptosis through activation of TRPV1 channel in hippocampus and dorsal root ganglion of rats.

    Science.gov (United States)

    Ghazizadeh, Vahid; Nazıroğlu, Mustafa

    2014-09-01

    Incidence rates of epilepsy and use of Wi-Fi worldwide have been increasing. TRPV1 is a Ca(2+) permeable and non-selective channel, gated by noxious heat, oxidative stress and capsaicin (CAP). The hyperthermia and oxidant effects of Wi-Fi may induce apoptosis and Ca(2+) entry through activation of TRPV1 channel in epilepsy. Therefore, we tested the effects of Wi-Fi (2.45 GHz) exposure on Ca(2+) influx, oxidative stress and apoptosis through TRPV1 channel in the murine dorsal root ganglion (DRG) and hippocampus of pentylentetrazol (PTZ)-induced epileptic rats. Rats in the present study were divided into two groups as controls and PTZ. The PTZ groups were divided into two subgroups namely PTZ + Wi-Fi and PTZ + Wi-Fi + capsazepine (CPZ). The hippocampal and DRG neurons were freshly isolated from the rats. The DRG and hippocampus in PTZ + Wi-Fi and PTZ + Wi-Fi + CPZ groups were exposed to Wi-Fi for 1 hour before CAP stimulation. The cytosolic free Ca(2+), reactive oxygen species production, apoptosis, mitochondrial membrane depolarization, caspase-3 and -9 values in hippocampus were higher in the PTZ group than in the control although cell viability values decreased. The Wi-Fi exposure induced additional effects on the cytosolic Ca(2+) increase. However, pretreatment of the neurons with CPZ, results in a protection against epilepsy-induced Ca(2+) influx, apoptosis and oxidative damages. In results of whole cell patch-clamp experiments, treatment of DRG with Ca(2+) channel antagonists [thapsigargin, verapamil + diltiazem, 2-APB, MK-801] indicated that Wi-Fi exposure induced Ca(2+) influx via the TRPV1 channels. In conclusion, epilepsy and Wi-Fi in our experimental model is involved in Ca(2+) influx and oxidative stress-induced hippocampal and DRG death through activation of TRPV1 channels, and negative modulation of this channel activity by CPZ pretreatment may account for the neuroprotective activity against oxidative stress.

  14. “A Swarm in July”: Beekeeping Perspectives on the Old English Wið Ymbe Charm

    Directory of Open Access Journals (Sweden)

    Lori Ann Garner

    2011-10-01

    Full Text Available This exploration of an Old English charm against a swarm of bees (_wið ymbe_ augments and complements prior work on this enigmatic text by bringing knowledgeable and experienced beekeepers _directly_ into the discussion. Based on insights gained through sharing the text with them and inviting their reactions, this essay offers a highly collaborative and genuinely interdisciplinary interpretation of both the charm’s ritual instructions and the poetic incantation.

  15. Risk-Informed Interference Assessment for Shared Spectrum Bands: A Wi-Fi/LTE Coexistence Case Study

    OpenAIRE

    Voicu, Andra M.; Simić, Ljiljana; de Vries, J. Pierre; Petrova, Marina; Mähönen, Petri

    2017-01-01

    Interference evaluation is crucial when deciding whether and how wireless technologies should operate. In this paper we demonstrate the benefit of risk-informed interference assessment to aid spectrum regulators in making decisions, and to readily convey engineering insight. Our contributions are: we apply, for the first time, risk assessment to a problem of inter-technology spectrum sharing, i.e. Wi-Fi/LTE in the 5 GHz unlicensed band, and we demonstrate that this method comprehensively quan...

  16. Uji Sitotoksisitas Ekstrak Ethanol 70 % Herba Ceplukan (Physalis angulata Linn. Terhadap Sel WiDr Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Ira Djajanegara

    2017-03-01

    Full Text Available Herba ceplukan (Physalis angulata Linn merupakan salah satu bahan alam yang digunakanmasyarakat untuk pengobatan tradisional sebagai antikanker. Pada penelitian sebelumnya hasilpengujian ekstrak ethanol 70% herba ceplukan (Physalis angulata Linn. terhadap Artemia salinaLeach (larva udang dengan metode Brine Shirmp Lethality Test (BSLT diketahui memiliki sifattoksik dengan nilai LC50 sebesar 39,63 μg/ml. Untuk itu dilakukan penelitian yang bertujuanmengetahui efek sitotoksisitas ekstrak ethanol 70% herba ceplukan dengan menentukan kadaryang menyebabkan 50% sel mati (LC50 terhadap sel kanker usus WiDr secara in vitro. Herbaceplukan (Physalis angulata Linn diekstraksi dengan cara maserasi dengan penyari ethanol 70%.Sel kanker usus WiDr diperlakukan dengan ekstrak ethanol 70% herba ceplukan dengan seri kadaryaitu 1000, 500, 250, 125, 62.5, 31.25, 15.125 dan 7.81 μg/ml selama 24 jam. Sebagai kontrolpositif digunakan doksorubisin dengan seri kadar sebagai berikut: 2; 1; 0.5; 0.25; 0.12; 0.06; 0.03dan 0 .01 μg/ml. Uji sitotoksisitas dilakukan dengan menginkubasi sel kanker usus WiDr dengankepadatan akhir sel 2.104 sel / ml persumuran plat kultur. Uji sitotosisitas ini menggunakanmetode perhitungan langsung dengan bantuan alat haemocytometer. Hasil penelitian menunjukkanbahwa ekstrak ethanol 70% herba ceplukan (Physalis angulata Linn. mempunyai sitotoksisitassebesar 86,84 ìg/ml terhadap sel kanker usus WiDr yang di atas nilai indikator positif sebagaibahan bersifat sitotoksik yaitu sebesar > 30 ìg/ml. Nilai tersebut juga sangat lebih tinggi biladibandingkan dengan nilai LC50 doksorubisin sebagai pembanding sebesar 0,113 μg/ml.

  17. Optical network unit placement in Fiber-Wireless (FiWi) access network by Moth-Flame optimization algorithm

    Science.gov (United States)

    Singh, Puja; Prakash, Shashi

    2017-07-01

    Hybrid wireless-optical broadband access network (WOBAN) or Fiber-Wireless (FiWi) is the integration of wireless access network and optical network. This hybrid multi-domain network adopts the advantages of wireless and optical domains and serves the demand of technology savvy users. FiWi exhibits the properties of cost effectiveness, robustness, flexibility, high capacity, reliability and is self organized. Optical Network Unit (ONU) placement problem in FiWi contributes in simplifying the network design and enhances the performance in terms of cost efficiency and increased throughput. Several individual-based algorithms, such as Simulated Annealing (SA), Tabu Search, etc. have been suggested for ONU placement, but these algorithms suffer from premature convergence (trapping in a local optima). The present research work undertakes the deployment of FiWi and proposes a novel nature-inspired heuristic paradigm called Moth-Flame optimization (MFO) algorithm for multiple optical network units' placement. MFO is a population based algorithm. Population-based algorithms are better in handling local optima avoidance. The simulation results are compared with the existing Greedy and Simulated Annealing algorithms to optimize the position of ONUs. To the best of our knowledge, MFO algorithm has been used for the first time in this domain, moreover it has been able to provide very promising and competitive results. The performance of MFO algorithm has been analyzed by varying the 'b' parameter. MFO algorithm results in faster convergence than the existing strategies of Greedy and SA and returns a lower value of overall cost function. The results exhibit the dependence of the objective function on the distribution of wireless users also.

  18. Refining Wi-Fi Based Indoor Localization with Li-Fi Assisted Model Calibration in Smart Buildings

    OpenAIRE

    Huang, Qian; Zhang, Yuanzhi; Ge, Zhenhao; Lu, Chao

    2016-01-01

    In recent years, there has been an increasing number of information technologies utilized in buildings to advance the idea of "smart buildings". Among various potential techniques, the use of Wi-Fi based indoor positioning allows to locate and track smartphone users inside a building, therefore, location-aware intelligent solutions can be applied to control and of building operations. These location-aware indoor services (e.g., path finding, internet of things, location based advertising) dem...

  19. The activities of the Monastery of the Discalced Carmelites in Wiśnicz (1630–1782

    Directory of Open Access Journals (Sweden)

    Szczepan T. Praśkiewicz

    2013-12-01

    Full Text Available Commencing with the words spoken by Stanisław Lubomirski, the founder of the monastery, in 1641, in the presence of King Władysław IV, that „the religious fraternity of Wiśnicz should strictly follow their religious discipline”, this study outlines the activities of the Discalced Carmelites in Wiśnicz, noting that the first and most fundamental aim of their apostolic religious life is fidelity to the charism and the living testimony which St. Teresa of Jesus, the reformer of the Carmelites, expressed in the words: „operibus magis, quam verbis doceant”. This study shows the activity of the monastery ad intra and ad extra. The first section elaborates upon the formation of novices and seminarians, the role of the richly stocked monastery library, the Provincial Chapters held in Wiśnicz, the care and management of goods and the maintenance of the facilities. On the other hand, in the ad extra section, there are descriptions of sacramental ministry, preaching of the Word of God in the monastery church, the promotion of local vocations, travels for the purposes of evangelization, the writing activities of the religious men and the specific apostolate of the Order (to spread devotion to Blessed Mary with a special promotion of the Scapular, the devotion to St. Joseph, to St. Teresa of Jesus and giving spiritual direction to the Discalced Carmelite nuns, as well as evidence of assistance provided by them during periods of exile due to wars and plagues. In a nutshell, the Discalced Carmelites of Wiśnicz knew that you need contemplata aliis tradere and that suprema lex is salus animarum.

  20. On the Modelling of the Mobile WiMAX (IEEE 802.16e Uplink Scheduler

    Directory of Open Access Journals (Sweden)

    Darmawaty Mohd Ali

    2010-01-01

    Full Text Available Packet scheduling has drawn a great deal of attention in the field of wireless networks as it plays an important role in distributing shared resources in a network. The process involves allocating the bandwidth among users and determining their transmission order. In this paper an uplink (UL scheduling algorithm for the Mobile Worldwide Interoperability for Microwave Access (WiMAX network based on the cyclic polling model is proposed. The model in this study consists of five queues (UGS, ertPS, rtPS, nrtPS, and BE visited by a single server. A threshold policy is imposed to the nrtPS queue to ensure that the delay constraint of real time traffic (UGS, ertPS, and rtPS is not violated making this approach original in comparison to the existing contributions. A mathematical model is formulated for the weighted sum of the mean waiting time of each individual queues based on the pseudo-conservation law. The results of the analysis are useful in obtaining or testing approximation for individual mean waiting time especially when queues are asymmetric (where each queue may have different stochastic characteristic such as arrival rate and service time distribution and when their number is large (more than 2 queues.

  1. The pollen spectrum of honeys of Lipnik Gmina (Świętokrzyskie Province

    Directory of Open Access Journals (Sweden)

    Ernest Stawiarz

    2012-12-01

    Full Text Available During 2003 and 2004 apicultural seasons, 25 samples of honeys were collected in 10 localities of Lipnik (świętokrzyskie Province countryside. Pollen analysis was made according to the requirements of the International Commission for Bee Botany IUSB (Louveaux et al., 1978. There were identified pollen of 85 taxa in the examined samples of honeys: pollen of 62 nectariferous and 23 non-nectariferous plants. Participation of non-nectariferous plant pollen in particular samples ranged between 0.3 and 28.4%. Among the nectariferous plant pollen, the highest pollen frequency (above 50% have been stated for Brassicaceae (with Brassica napus, Prunus type, Trifolium repens, Anthriscus type, Salix, Aesculus, Rubus type, Tilia, Taraxacum type, Galeopsis and Heracleum type, among non-nectariferous plans: Poaceae, Papaver and Fragaria. On average, a particular honey contained 16 pollen types of nectariferous plants (range 7-26 and 7 of non-nectariferous (range 1-13. Among the examined samples, there were 11 specific honeys: 7 compatible with the Polish Standard - 4 samples of Brassica napus honeys, 2 Robinia pseudacacia, 1 Tilia, and 4 samples of honeys out of his this standard. There were 3 Galeopsis honeys and 1 honey from Phacelia. The remaining 14 samples were classified as multifloral honeys compatible with the Polish Standard. The woods and scrubs as well as meadows and pastures supplied main sources of honeybee flow in the examined area.

  2. Community Theories of Change: Linking Environmental Justice to Sustainability through Stakeholder Perceptions in Milwaukee (WI, USA

    Directory of Open Access Journals (Sweden)

    Kaitlyn Hornik

    2016-09-01

    Full Text Available Environmental justice and sustainability are compatible lenses, yet action toward equity is often missing from urban sustainability initiatives. This study aims to assess the cohesion of these frameworks in practice. To do this, we parse individuals’ theories of change, or how they identify and propose to resolve environmental injustices in the pursuit of sustainability. We posit that these theories of change are comprised of three main components: (1 perceived environmental benefits and burdens; (2 the causal pathways of environmental and social injustice; and (3 visions for positive change. Drawing from 35 stakeholder interviews in Milwaukee (WI, USA we examine individual and institutional perspectives on environmental and social change and their links to the production of injustice. Our findings reveal that participants do not distinguish between environmental and social injustices. Instead, both social and environmental factors are implicated in injustice. Furthermore, we identify two mental maps for how social and economic change reproduce injustice. These findings suggest the need to reorient how urban injustice is considered and make efforts to acknowledge how a diversity of operational theories of change could either be divisive or could bring environmental justice and sustainability initiatives together.

  3. On the Verification of a WiMax Design Using Symbolic Simulation

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    Gabriela Nicolescu

    2013-07-01

    Full Text Available In top-down multi-level design methodologies, design descriptions at higher levels of abstraction are incrementally refined to the final realizations. Simulation based techniques have traditionally been used to verify that such model refinements do not change the design functionality. Unfortunately, with computer simulations it is not possible to completely check that a design transformation is correct in a reasonable amount of time, as the number of test patterns required to do so increase exponentially with the number of system state variables. In this paper, we propose a methodology for the verification of conformance of models generated at higher levels of abstraction in the design process to the design specifications. We model the system behavior using sequence of recurrence equations. We then use symbolic simulation together with equivalence checking and property checking techniques for design verification. Using our proposed method, we have verified the equivalence of three WiMax system models at different levels of design abstraction, and the correctness of various system properties on those models. Our symbolic modeling and verification experiments show that the proposed verification methodology provides performance advantage over its numerical counterpart.

  4. UWB Monopole Antenna with Band Notched Characteristics Mitigating Interference with WiMAX

    Directory of Open Access Journals (Sweden)

    A. A. Ibrahim

    2017-06-01

    Full Text Available Compact asymmetric coplanar strip (ACS - fed monopole antenna is presented in this paper for operation in ultra wide-band (UWB applications. The antenna is composed of a semi-elliptical monopole and lateral coplanar ground plane to operate in the UWB range. It occupies a very small size of 28 × 11.5 mm 2 and is mounted on low cost FR4 substrate of 1.6 mm thickness and dielectric constant of 4.4. Band notched structure is applied to the proposed antenna to assure the rejection of WiMAX frequency band centered at 3.5 GHz to minimize the interference of the communication system with this service. The radiation characteristics of the proposed ACS-fed monopole antenna is nearly omnidirectional with moderate gain over the entire UWB frequency range. The measurements of the fabricated model confirm the designed behavior. The compactness in size, cheap cost and simple feeding technique make it as a good candidate to be integrated within the portable devices for wireless communication.

  5. Ambient radiofrequency power: the impact of the number of devices in a Wi-Fi network.

    Science.gov (United States)

    Malone, David; Malone, Lesley A

    2009-06-01

    This paper considers how the total radiofrequency power varies as the number of devices in a Wi-Fi network increases. Under the assumption that all devices in the network always have data to transmit, we show that work from network engineering can be adapted to calculate the total transmitted power, accounting for the possibility of multiple devices transmitting at the same time. The paper focuses on total transmitted power as it gives an upper bound on exposure and makes the impact of multiple devices clear. The results show that the number of devices does have a significant impact on the radiated power. For example, one station transmitting small packets in unicast mode gives about half the nominal power value; to reach nominal value around 25 devices are required, and 150% of the nominal value is achieved around 350 devices. We see that 802.11's transmission protocol is usually effective in limiting the power even in very large 802.11 networks.

  6. A Wi-Fi based Electronic Road Sign for Enhancing the Awareness of Vehicle Driver

    Science.gov (United States)

    Bhawiyuga, A.; Sabriansyah, R. A.; Yahya, W.; E Putra, R.

    2017-01-01

    Reducing the road accident rate is one of the city goal in the area of transportation. One of the effort to reach that goal is done by deploying various signs across the road. However, the role of those road signs can be diminished once the vehicle drivers intentionally or unintentionally disobey the rule indicated on those signs. In order to increase the awareness of the driver, we can employ the vehicular network concept in which a vehicle can communicate with another vehicles or with the infrastructure installed along the road. For realizing that idea, we propose the implementation of communication equipped road sign system which consists of two components: Road Side Unit (RSU) module deployed at road sign and On Board Unit (OBU) module deployed at each vehicle. In our proposed scheme, both of the devices communicate each other through the widely-used Wi-Fi protocol (IEEE 802.11n) operating in ad-hoc mode. While a OBU equipped vehicle is moving towards the communication range of RSU, it will make an association to a predefined wireless ad-hoc network. Once it is associated, the OBU can receive message broadcast by the RSU. Upon reception, OBU display alert message indicating that the vehicle is approaching a road sign. From performance testing we observe that the proposed system can give relatively good service the vehicle moving as fast as speed 90km/h with the distance as far as 90m.

  7. Conditional Entropy and Location Error in Indoor Localization Using Probabilistic Wi-Fi Fingerprinting.

    Science.gov (United States)

    Berkvens, Rafael; Peremans, Herbert; Weyn, Maarten

    2016-10-02

    Localization systems are increasingly valuable, but their location estimates are only useful when the uncertainty of the estimate is known. This uncertainty is currently calculated as the location error given a ground truth, which is then used as a static measure in sometimes very different environments. In contrast, we propose the use of the conditional entropy of a posterior probability distribution as a complementary measure of uncertainty. This measure has the advantage of being dynamic, i.e., it can be calculated during localization based on individual sensor measurements, does not require a ground truth, and can be applied to discrete localization algorithms. Furthermore, for every consistent location estimation algorithm, both the location error and the conditional entropy measures must be related, i.e., a low entropy should always correspond with a small location error, while a high entropy can correspond with either a small or large location error. We validate this relationship experimentally by calculating both measures of uncertainty in three publicly available datasets using probabilistic Wi-Fi fingerprinting with eight different implementations of the sensor model. We show that the discrepancy between these measures, i.e., many location estimates having a high location error while simultaneously having a low conditional entropy, is largest for the least realistic implementations of the probabilistic sensor model. Based on the results presented in this paper, we conclude that conditional entropy, being dynamic, complementary to location error, and applicable to both continuous and discrete localization, provides an important extra means of characterizing a localization method.

  8. Fusing Bluetooth Beacon Data with Wi-Fi Radiomaps for Improved Indoor Localization

    Science.gov (United States)

    Kanaris, Loizos; Kokkinis, Akis; Liotta, Antonio; Stavrou, Stavros

    2017-01-01

    Indoor user localization and tracking are instrumental to a broad range of services and applications in the Internet of Things (IoT) and particularly in Body Sensor Networks (BSN) and Ambient Assisted Living (AAL) scenarios. Due to the widespread availability of IEEE 802.11, many localization platforms have been proposed, based on the Wi-Fi Received Signal Strength (RSS) indicator, using algorithms such as K-Nearest Neighbour (KNN), Maximum A Posteriori (MAP) and Minimum Mean Square Error (MMSE). In this paper, we introduce a hybrid method that combines the simplicity (and low cost) of Bluetooth Low Energy (BLE) and the popular 802.11 infrastructure, to improve the accuracy of indoor localization platforms. Building on KNN, we propose a new positioning algorithm (dubbed i-KNN) which is able to filter the initial fingerprint dataset (i.e., the radiomap), after considering the proximity of RSS fingerprints with respect to the BLE devices. In this way, i-KNN provides an optimised small subset of possible user locations, based on which it finally estimates the user position. The proposed methodology achieves fast positioning estimation due to the utilization of a fragment of the initial fingerprint dataset, while at the same time improves positioning accuracy by minimizing any calculation errors. PMID:28394268

  9. A plug’n’play WiFi surface-mount dual-loop antenna

    Directory of Open Access Journals (Sweden)

    Pedro Chamorro-Posada

    2017-04-01

    Full Text Available We present the design, modelling and characterization in the 2.4 GHz band of a B-shaped antenna consisting of a dual circular loop over a conductor plane. The proposed design is intrinsically unbalanced and features a very good match to a 50 Ω line at resonance, which makes our device essentially plug’n’play for a coaxial cable feed. Another interesting property of the proposed antenna is its simplicity of construction. The antenna has been modelled using the moment method. A prototype resonant at 2.4 GHz has been built and we have measured its impedance in this spectral region. The radiation pattern and the gain at resonance have also been characterized and the device has been shown to provide 6.31 dBi gain. The overall properties of the device make it an excellent option to provide WiFi connectivity when required in open hardware implementations.

  10. WiFi-Based Real-Time Calibration-Free Passive Human Motion Detection †

    Science.gov (United States)

    Gong, Liangyi; Yang, Wu; Man, Dapeng; Dong, Guozhong; Yu, Miao; Lv, Jiguang

    2015-01-01

    With the rapid development of WLAN technology, wireless device-free passive human detection becomes a newly-developing technique and holds more potential to worldwide and ubiquitous smart applications. Recently, indoor fine-grained device-free passive human motion detection based on the PHY layer information is rapidly developed. Previous wireless device-free passive human detection systems either rely on deploying specialized systems with dense transmitter-receiver links or elaborate off-line training process, which blocks rapid deployment and weakens system robustness. In the paper, we explore to research a novel fine-grained real-time calibration-free device-free passive human motion via physical layer information, which is independent of indoor scenarios and needs no prior-calibration and normal profile. We investigate sensitivities of amplitude and phase to human motion, and discover that phase feature is more sensitive to human motion, especially to slow human motion. Aiming at lightweight and robust device-free passive human motion detection, we develop two novel and practical schemes: short-term averaged variance ratio (SVR) and long-term averaged variance ratio (LVR). We realize system design with commercial WiFi devices and evaluate it in typical multipath-rich indoor scenarios. As demonstrated in the experiments, our approach can achieve a high detection rate and low false positive rate. PMID:26703612

  11. WiFi-Based Real-Time Calibration-Free Passive Human Motion Detection.

    Science.gov (United States)

    Gong, Liangyi; Yang, Wu; Man, Dapeng; Dong, Guozhong; Yu, Miao; Lv, Jiguang

    2015-12-21

    With the rapid development of WLAN technology, wireless device-free passive human detection becomes a newly-developing technique and holds more potential to worldwide and ubiquitous smart applications. Recently, indoor fine-grained device-free passive human motion detection based on the PHY layer information is rapidly developed. Previous wireless device-free passive human detection systems either rely on deploying specialized systems with dense transmitter-receiver links or elaborate off-line training process, which blocks rapid deployment and weakens system robustness. In the paper, we explore to research a novel fine-grained real-time calibration-free device-free passive human motion via physical layer information, which is independent of indoor scenarios and needs no prior-calibration and normal profile. We investigate sensitivities of amplitude and phase to human motion, and discover that phase feature is more sensitive to human motion, especially to slow human motion. Aiming at lightweight and robust device-free passive human motion detection, we develop two novel and practical schemes: short-term averaged variance ratio (SVR) and long-term averaged variance ratio (LVR). We realize system design with commercial WiFi devices and evaluate it in typical multipath-rich indoor scenarios. As demonstrated in the experiments, our approach can achieve a high detection rate and low false positive rate.

  12. Fusing Bluetooth Beacon Data with Wi-Fi Radiomaps for Improved Indoor Localization.

    Science.gov (United States)

    Kanaris, Loizos; Kokkinis, Akis; Liotta, Antonio; Stavrou, Stavros

    2017-04-10

    Indoor user localization and tracking are instrumental to a broad range of services and applications in the Internet of Things (IoT) and particularly in Body Sensor Networks (BSN) and Ambient Assisted Living (AAL) scenarios. Due to the widespread availability of IEEE 802.11, many localization platforms have been proposed, based on the Wi-Fi Received Signal Strength (RSS) indicator, using algorithms such as K -Nearest Neighbour (KNN), Maximum A Posteriori (MAP) and Minimum Mean Square Error (MMSE). In this paper, we introduce a hybrid method that combines the simplicity (and low cost) of Bluetooth Low Energy (BLE) and the popular 802.11 infrastructure, to improve the accuracy of indoor localization platforms. Building on KNN, we propose a new positioning algorithm (dubbed i-KNN) which is able to filter the initial fingerprint dataset (i.e., the radiomap), after considering the proximity of RSS fingerprints with respect to the BLE devices. In this way, i-KNN provides an optimised small subset of possible user locations, based on which it finally estimates the user position. The proposed methodology achieves fast positioning estimation due to the utilization of a fragment of the initial fingerprint dataset, while at the same time improves positioning accuracy by minimizing any calculation errors.

  13. Fusing Bluetooth Beacon Data with Wi-Fi Radiomaps for Improved Indoor Localization

    Directory of Open Access Journals (Sweden)

    Loizos Kanaris

    2017-04-01

    Full Text Available Indoor user localization and tracking are instrumental to a broad range of services and applications in the Internet of Things (IoT and particularly in Body Sensor Networks (BSN and Ambient Assisted Living (AAL scenarios. Due to the widespread availability of IEEE 802.11, many localization platforms have been proposed, based on the Wi-Fi Received Signal Strength (RSS indicator, using algorithms such as K-Nearest Neighbour (KNN, Maximum A Posteriori (MAP and Minimum Mean Square Error (MMSE. In this paper, we introduce a hybrid method that combines the simplicity (and low cost of Bluetooth Low Energy (BLE and the popular 802.11 infrastructure, to improve the accuracy of indoor localization platforms. Building on KNN, we propose a new positioning algorithm (dubbed i-KNN which is able to filter the initial fingerprint dataset (i.e., the radiomap, after considering the proximity of RSS fingerprints with respect to the BLE devices. In this way, i-KNN provides an optimised small subset of possible user locations, based on which it finally estimates the user position. The proposed methodology achieves fast positioning estimation due to the utilization of a fragment of the initial fingerprint dataset, while at the same time improves positioning accuracy by minimizing any calculation errors.

  14. Location-Aware POI Recommendation for Indoor Space by Exploiting WiFi Logs

    Directory of Open Access Journals (Sweden)

    Zengwei Zheng

    2017-01-01

    Full Text Available Indoor shopping trajectories provide us with a new approach to understanding user’s behaviour pattern in urban shopping mall, which can be derived from user-generated WiFi logs using indoor localization technology. In this paper, we propose a location-aware Point-of-Interest (POI recommendation service in urban shopping mall that offers a user a set of indoor POIs by considering both personal interest and location preference. The POI recommendation service cannot only improve user’s shopping experience but also help the store owner better understand user’s shopping preference and intent. Specifically, the proposed method consists of two phases: offline modelling and online recommendation. The offline modelling phase is designed to learn user preference by mining his/her historical shopping trajectories. The online recommendation phase automatically produces top-k recommended POIs based on the learnt preference. To demonstrate the utility of our proposed approach, we have performed a comprehensive experiment evaluation on a real-world dataset collected by 468 users over 33 days. The experimental results show that the proposed recommendation service achieves much better recommendation performance than several existing benchmark methods.

  15. Design & Analysis of Microstrip Patch Antenna Using Different Dielectric Materials for WiMAX Communication System

    Directory of Open Access Journals (Sweden)

    Md. Moidul Islam

    2016-03-01

    Full Text Available This Paper presents Microstrip patch antenna for WiMAX communication system which operate at 5.8 GHz frequency band. The main objective of this paper is to design and observe the performance of the designed microstrip patch antenna for different dielectric materials. The size of the designed antenna has been also miniaturized. Better performance is observed for FR4 and dupont-951 dielectric material. For FR4 radiation efficiency is-2.776 dB and total efficiency is -3.026 dB at 5.8 GHz, this indicates better performance. And for dupont-951 the return loss is much lower comparing to the other dielectric materials used in this research, which is -16.609 dB. Also for dupont-951 and FR4, VSWR is found 1.35 and 1.7 respectively which is desirable. Also the size of the antenna has been reduced. In this paper we also observed and analyzed the radiation pattern of far field region, gain, radiation efficiency and total efficiency for different dielectric materials.

  16. Ultrawideband Vivaldi Antenna for DVB-T, WLAN, and WiMAX Applications

    Directory of Open Access Journals (Sweden)

    Dalia M. Elsheakh

    2014-01-01

    Full Text Available Compact Vivaldi patch antenna with a parasitic meander line is presented in this paper. A PIN diode switch is used to connect and disconnect ultrahigh frequency band (UHF with ultrawide bandwidth (UWB. The operating frequencies can be switched among different services, depending on the switching states (ON/OFF to add the lower band when required. This antenna is suitable for portable DVB-T which extended from 450 MHz to 850 MHz receiver applications and the WLAN (Wireless Local Area Network IEEE 802.11b,g (5.1–5.8 GHz frequency bands and WiMAX band (3.3–3.8 GHz. The measured reflection coefficient of the proposed antenna is compared with the simulated one; good agreement is observed. Also, simulated radiation pattern of the antenna is presented. All simulations are carried out using the EM commercial simulator, high frequency structure simulator (HFSS ver.13.

  17. A Crowd-Sourcing Indoor Localization Algorithm via Optical Camera on a Smartphone Assisted by Wi-Fi Fingerprint RSSI.

    Science.gov (United States)

    Chen, Wei; Wang, Weiping; Li, Qun; Chang, Qiang; Hou, Hongtao

    2016-03-19

    Indoor positioning based on existing Wi-Fi fingerprints is becoming more and more common. Unfortunately, the Wi-Fi fingerprint is susceptible to multiple path interferences, signal attenuation, and environmental changes, which leads to low accuracy. Meanwhile, with the recent advances in charge-coupled device (CCD) technologies and the processing speed of smartphones, indoor positioning using the optical camera on a smartphone has become an attractive research topic; however, the major challenge is its high computational complexity; as a result, real-time positioning cannot be achieved. In this paper we introduce a crowd-sourcing indoor localization algorithm via an optical camera and orientation sensor on a smartphone to address these issues. First, we use Wi-Fi fingerprint based on the K Weighted Nearest Neighbor (KWNN) algorithm to make a coarse estimation. Second, we adopt a mean-weighted exponent algorithm to fuse optical image features and orientation sensor data as well as KWNN in the smartphone to refine the result. Furthermore, a crowd-sourcing approach is utilized to update and supplement the positioning database. We perform several experiments comparing our approach with other positioning algorithms on a common smartphone to evaluate the performance of the proposed sensor-calibrated algorithm, and the results demonstrate that the proposed algorithm could significantly improve accuracy, stability, and applicability of positioning.

  18. An Efficient Normalized Rank Based SVM for Room Level Indoor WiFi Localization with Diverse Devices

    Directory of Open Access Journals (Sweden)

    Yasmine Rezgui

    2017-01-01

    Full Text Available This paper proposes an efficient and effective WiFi fingerprinting-based indoor localization algorithm, which uses the Received Signal Strength Indicator (RSSI of WiFi signals. In practical harsh indoor environments, RSSI variation and hardware variance can significantly degrade the performance of fingerprinting-based localization methods. To address the problem of hardware variance and signal fluctuation in WiFi fingerprinting-based localization, we propose a novel normalized rank based Support Vector Machine classifier (NR-SVM. Moving from RSSI value based analysis to the normalized rank transformation based analysis, the principal features are prioritized and the dimensionalities of signature vectors are taken into account. The proposed method has been tested using sixteen different devices in a shopping mall with 88 shops. The experimental results demonstrate its robustness with no less than 98.75% correct estimation in 93.75% of the tested cases and 100% correct rate in 56.25% of cases. In the experiments, the new method shows better performance over the KNN, Naïve Bayes, Random Forest, and Neural Network algorithms. Furthermore, we have compared the proposed approach with three popular calibration-free transformation based methods, including difference method (DIFF, Signal Strength Difference (SSD, and the Hyperbolic Location Fingerprinting (HLF based SVM. The results show that the NR-SVM outperforms these popular methods.

  19. Modelo ARIMA para pronosticar valores de tráfico en una red de datos Wi-Fi

    Directory of Open Access Journals (Sweden)

    Cesar Augusto Hernández Suarez

    2009-05-01

    Full Text Available El presente artículo de investigación científica y tecnológica tiene por objetivo demostrar que las series de tiempo son una exce- lente herramienta para el modelamiento de tráfico de datos en redes Wi-Fi. Para lograr este objetivo se utilizó la metodología de Box-Jenkins, la cual se describe. El modelamiento de tráfico Wi-Fi a través de modelos correlacionados como las series de tiem- po, permiten ajustar gran parte de la dinámica del comportamiento de los datos en una ecuación y con base en esto estimar va- lores futuros de tráfico. Lo anterior es una ventaja para la planeación de cobertura, reservación de recursos y la realización de un control más oportuno y eficiente en forma integrada a diferentes niveles de la jerarquía funcional de la red de datos Wi-Fi. Como resultado de la investigación se obtuvo un modelo de tráfico ARIMA de orden 6, el cual realizó pronósticos de tráfico con valores del error cuadrático medio relativamente pequeños, para un periodo de 18 días.

  20. Estimating Bus Loads and OD Flows Using Location-Stamped Farebox and Wi-Fi Signal Data

    Directory of Open Access Journals (Sweden)

    Yuxiong Ji

    2017-01-01

    Full Text Available Electronic fareboxes integrated with Automatic Vehicle Location (AVL systems can provide location-stamped records to infer passenger boarding at individual stops. However, bus loads and Origin-Destination (OD flows, which are useful for route planning, design, and real-time controls, cannot be derived directly from farebox data. Recently, Wi-Fi sensors have been used to collect passenger OD flow information. But the data are insufficient to capture the variation of passenger demand across bus trips. In this study, we propose a hierarchical Bayesian model to estimate trip-level OD flow matrices and a period-level OD flow matrix using sampled OD flow data collected by Wi-Fi sensors and boarding data provided by fareboxes. Bus loads on each bus trip are derived directly from the estimated trip-level OD flow matrices. The proposed method is evaluated empirically on an operational bus route and the results demonstrate that it provides good and detailed transit route-level passenger demand information by combining farebox and Wi-Fi signal data.

  1. An overview of the SeaWiFS project and strategies for producing a climate research quality global ocean bio-optical time series

    Science.gov (United States)

    McClain, Charles R.; Feldman, Gene C.; Hooker, Stanford B.

    2004-01-01

    The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Project Office was formally initiated at the NASA Goddard Space Flight Center in 1990. Seven years later, the sensor was launched by Orbital Sciences Corporation under a data-buy contract to provide 5 years of science quality data for global ocean biogeochemistry research. To date, the SeaWiFS program has greatly exceeded the mission goals established over a decade ago in terms of data quality, data accessibility and usability, ocean community infrastructure development, cost efficiency, and community service. The SeaWiFS Project Office and its collaborators in the scientific community have made substantial contributions in the areas of satellite calibration, product validation, near-real time data access, field data collection, protocol development, in situ instrumentation technology, operational data system development, and desktop level-0 to level-3 processing software. One important aspect of the SeaWiFS program is the high level of science community cooperation and participation. This article summarizes the key activities and approaches the SeaWiFS Project Office pursued to define, achieve, and maintain the mission objectives. These achievements have enabled the user community to publish a large and growing volume of research such as those contributed to this special volume of Deep-Sea Research. Finally, some examples of major geophysical events (oceanic, atmospheric, and terrestrial) captured by SeaWiFS are presented to demonstrate the versatility of the sensor.

  2. Postnatal development and behavior effects of in-utero exposure of rats to radiofrequency waves emitted from conventional WiFi devices.

    Science.gov (United States)

    Othman, Haifa; Ammari, Mohamed; Rtibi, Kaïs; Bensaid, Noura; Sakly, Mohsen; Abdelmelek, Hafedh

    2017-06-01

    The present work investigated the effects of prenatal exposure to radiofrequency waves of conventional WiFi devices on postnatal development and behavior of rat offspring. Ten Wistar albino pregnant rats were randomly assigned to two groups (n=5). The experimental group was exposed to a 2.45GHz WiFi signal for 2h a day throughout gestation period. Control females were subjected to the same conditions as treated group without applying WiFi radiations. After delivery, the offspring was tested for physical and neurodevelopment during its 17 postnatal days (PND), then for anxiety (PND 28) and motricity (PND 40-43), as well as for cerebral oxidative stress response and cholinesterase activity in brain and serum (PND 28 and 43). Our main results showed that the in-utero WiFi exposure impaired offspring neurodevelopment during the first seventeen postnatal days without altering emotional and motor behavior at adult age. Besides, prenatal WiFi exposure induced cerebral oxidative stress imbalance (increase in malondialdehyde level (MDA) and hydrogen peroxide (H 2 O 2 ) levels and decrease in catalase (CAT) and superoxide dismutase (SOD) activities) at 28 but not 43days old, also the exposure affected acethylcolinesterase activity at both cerebral and seric levels. Thus, the current study revealed that maternal exposure to WiFi radiofrequencies led to various adverse neurological effects in the offspring by affecting neurodevelopment, cerebral stress equilibrium and cholinesterase activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The history of the Discalced Carmelite Monastery in Nowy Wiśnicz between 1630–2009

    Directory of Open Access Journals (Sweden)

    Zdzisław Gogola

    2013-12-01

    Full Text Available After winning the battle against the Turks at Chocim in 1621, Stanisław Lubomirski, the owner of Wiśnicz, founded the monastery of the Discalced Carmelites as a votive offering to God. Religious authorities feared the location of the monastery and church in private estates due to the potential impact of the court on religious life. In 1622 the founder began the construction at full swing, employing great numbers of labourers and prisoners of war. The process of the construction was supervised by Lubomirski’s court architect, an Italian Maciej Trapola. The buildings were characterized by a modern style of architecture and they occupied a unique position in the history of Polish architecture. The property was fortified and also served as defence for the castle of Wiśnicz. On May 26, 1630 a ceremony was held to introduce the Carmelites to the monastery in Wiśnicz. The construction works were completed in 1635. The interior was very well equipped and, in the seventeenth century, was considered one of the best equipped Discalced Carmelite monasteries. On September 1, 1650 the Swedes captured the castle and monastery destroying, looting and pillaging the most precious things including the library and the works of art. The monastery in Wiśnicz after the partition of Poland was incorporated into Austria. Emperor Joseph II through his policies led to the suppression of monasteries, including the monastery in Wiśnicz. He robbed the monastery, took away the monastic treasury and allocated the church estates to religious funds. The most valuable works of art were taken to Vienna (two wagons of paintings. The buildings of the monastery were converted to perform the functions of a prison, criminal court and housing for judges. After regaining independence in 1918, despite the protests of the Carmelites, the prison in the monastery continued to function. In September 1939, the Germans used it as a camp for prisoners of war and later a concentration

  4. Enhanced DNA double-strand break repair of microbeam targeted A549 lung carcinoma cells by adjacent WI38 normal lung fibroblast cells via bi-directional signaling.

    Science.gov (United States)

    Kobayashi, Alisa; Tengku Ahmad, Tengku Ahbrizal Farizal; Autsavapromporn, Narongchai; Oikawa, Masakazu; Homma-Takeda, Shino; Furusawa, Yoshiya; Wang, Jun; Konishi, Teruaki

    2017-10-01

    Understanding the mechanisms underlying the radiation-induced bystander effect (RIBE) and bi-directional signaling between irradiated carcinoma cells and their surrounding non-irradiated normal cells is relevant to cancer radiotherapy. The present study investigated propagation of RIBE signals between human lung carcinoma A549 cells and normal lung fibroblast WI38 cells in bystander cells, either directly or indirectly contacting irradiated A549 cells. We prepared A549-GFP/WI38 co-cultures and A549-GFP/A549 co-cultures, in which A549-GFP cells stably expressing H2BGFP were co-cultured with either A549 cells or WI38 cells, respectively. Using the SPICE-NIRS microbeam, only the A549-GFP cells were irradiated with 500 protons per cell. The level of γ-H2AX, a marker for DNA double-strand breaks (DSB), was subsequently measured for up to 24h post-irradiation in three categories of cells: (1) "targeted"/irradiated A549-GFP cells; (2) "neighboring"/non-irradiated cells directly contacting the "targeted" cells; and (3) "distant"/non-irradiated cells, which were not in direct contact with the "targeted" cells. We found that DSB repair in targeted A549-GFP cells was enhanced by co-cultured WI38 cells. The bystander response in A549-GFP/A549 cell co-cultures, as marked by γ-H2AX levels at 8h post-irradiation, showed a decrease to non-irradiated control level when approaching 24h, while the neighboring/distant bystander WI38 cells in A549-GFP/WI38 co-cultures was maintained at a similar level until 24h post-irradiation. Surprisingly, distant A549-GFP cells in A549-GFP/WI38 co-cultures showed time dependency similar to bystander WI38 cells, but not to distant cells in A549-GFP/A549 co-cultures. These observations indicate that γ-H2AX was induced in WI38 cells as a result of RIBE. WI38 cells were not only involved in rescue of targeted A549, but also in the modification of RIBE against distant A549-GFP cells. The present results demonstrate that radiation-induced bi

  5. Wi-Fi Salvador: mapeamento colaborativo e redes sem fio no Brasil

    Directory of Open Access Journals (Sweden)

    André Lemos

    Full Text Available O trabalho faz uma breve demonstração de políticas públicas para inclusão digital por meio da disponibilização do acesso à internet por meio de redes sem fio e discute a forma como as pessoas se relacionam com os lugares, de acordo com a existência ou inexistência de acessibilidade à internet. O objetivo é discutir o acesso à internet pelas redes sem fio no Brasil e, mais especificamente, na cidade de Salvador. Este trabalho é fruto de pesquisa realizada no âmbito do Grupo de Pesquisa em Cibercidades da Universidade Federal da Bahia e mostra como a intersecção entre o ciberespaço e o espaço físico está trazendo novas experiências de uso e de produção de sentido sobre a cidade. Hoje, a urbe contemporânea supõe ampla conexão e associações entre espaço físico e "territórios informacionais" para os mais diversos fins, em uma aliança entre a mobilidade física e a informacional. Assim, mostramos os principais desafios teóricos em jogo com as mídias digitais, as redes sem fio e o espaço urbano. A partir deste aporte, o trabalho faz uma análise do projeto Wi-Fi Salvador, o maior mapeamento de redes sem fio já realizado na capital baiana e no Brasil.

  6. Indoor Smartphone Navigation Using a Combination of Wi-Fi and Inertial Navigation with Intelligent Checkpoints

    Science.gov (United States)

    Hofer, H.; Retscher, G.

    2017-09-01

    For Wi-Fi positioning location fingerprinting is one of the most commonly employed localization technique. To achieve an acceptable level of positioning accuracy on the few meter level, i.e., to provide at least room resolution in buildings, such an approach is very labour consuming as it requires a high density of reference points. Thus, the novel approach developed aims at a significant reduction of workload for the training phase. The basic idea is to intelligently choose waypoints along possible users' trajectories in the indoor environment. These waypoints are termed intelligent checkpoints (iCPs) and serve as reference points for the fingerprinting localization approach. They are selected along the trajectories in such a way that they define a logical sequence with their ascending order. Thereby, the iCPs are located, for instance, at doors at entrances to buildings, rooms, along corridors, etc., or in low density along the trajectory to provide a suitable absolute user localization. Continuous positioning between these iCPs is obtained with the help of the smartphones' inertial sensors. While walking along a selected trajectory to the destination a dynamic recognition of the iCPs is performed and the drift of the inertial sensors is reduced as the iCP recognition serves as absolute position update. Conducted experiments in a multi-storey office building have shown that positioning accuracy of around 2.0 m are achievable which goes along with a reduction of workload by three quarter using this novel approach. The iCP concept and performance are presented and demonstrated in this paper.

  7. Conditional Entropy and Location Error in Indoor Localization Using Probabilistic Wi-Fi Fingerprinting

    Directory of Open Access Journals (Sweden)

    Rafael Berkvens

    2016-10-01

    Full Text Available Localization systems are increasingly valuable, but their location estimates are only useful when the uncertainty of the estimate is known. This uncertainty is currently calculated as the location error given a ground truth, which is then used as a static measure in sometimes very different environments. In contrast, we propose the use of the conditional entropy of a posterior probability distribution as a complementary measure of uncertainty. This measure has the advantage of being dynamic, i.e., it can be calculated during localization based on individual sensor measurements, does not require a ground truth, and can be applied to discrete localization algorithms. Furthermore, for every consistent location estimation algorithm, both the location error and the conditional entropy measures must be related, i.e., a low entropy should always correspond with a small location error, while a high entropy can correspond with either a small or large location error. We validate this relationship experimentally by calculating both measures of uncertainty in three publicly available datasets using probabilistic Wi-Fi fingerprinting with eight different implementations of the sensor model. We show that the discrepancy between these measures, i.e., many location estimates having a high location error while simultaneously having a low conditional entropy, is largest for the least realistic implementations of the probabilistic sensor model. Based on the results presented in this paper, we conclude that conditional entropy, being dynamic, complementary to location error, and applicable to both continuous and discrete localization, provides an important extra means of characterizing a localization method.

  8. WiFi RFID demonstration for resource tracking in a statewide disaster drill.

    Science.gov (United States)

    Cole, Stacey L; Siddiqui, Javeed; Harry, David J; Sandrock, Christian E

    2011-01-01

    To investigate the capabilities of Radio Frequency Identification (RFID) tracking of patients and medical equipment during a simulated disaster response scenario. RFID infrastructure was deployed at two small rural hospitals, in one large academic medical center and in two vehicles. Several item types from the mutual aid equipment list were selected for tracking during the demonstration. A central database server was installed at the UC Davis Medical Center (UCDMC) that collected RFID information from all constituent sites. The system was tested during a statewide disaster drill. During the drill, volunteers at UCDMC were selected to locate assets using the traditional method of locating resources and then using the RFID system. This study demonstrated the effectiveness of RFID infrastructure in real-time resource identification and tracking. Volunteers at UCDMC were able to locate assets substantially faster using RFID, demonstrating that real-time geolocation can be substantially more efficient and accurate than traditional manual methods. A mobile, Global Positioning System (GPS)-enabled RFID system was installed in a pediatric ambulance and connected to the central RFID database via secure cellular communication. This system is unique in that it provides for seamless region-wide tracking that adaptively uses and seamlessly integrates both outdoor cellular-based mobile tracking and indoor WiFi-based tracking. RFID tracking can provide a real-time picture of the medical situation across medical facilities and other critical locations, leading to a more coordinated deployment of resources. The RFID system deployed during this study demonstrated the potential to improve the ability to locate and track victims, healthcare professionals, and medical equipment during a region-wide disaster.

  9. Microscopic heat pulse-induced calcium dynamics in single WI-38 fibroblasts.

    Science.gov (United States)

    Itoh, Hideki; Oyama, Kotaro; Suzuki, Madoka; Ishiwata, Shin'ichi

    2014-01-01

    Temperature-sensitive Ca(2+) dynamics occur primarily through transient receptor potential channels, but also by means of Ca(2+) channels and pumps on the endoplasmic reticulum membrane. As such, cytoplasmic Ca(2+) concentration ([Ca(2+)]cyt) is re-equilibrated by changes in ambient temperature. The present study investigated the effects of heat pulses (heating duration: 2 s or 150 s) on [Ca(2+)]cyt in single WI-38 fibroblasts, which are considered as normal cells. We found that Ca(2+) burst occurred immediately after short (2 s) heat pulse, which is similar to our previous report on HeLa cells, but with less thermosensitivity. The heat pulses originated from a focused 1455-nm infrared laser light were applied in the vicinity of cells under the optical microscope. Ca(2+) bursts induced by the heat pulse were suppressed by treating cells with inhibitors for sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) or inositol trisphosphate receptor (IP3R). Long (150 s) heat pulses also induced Ca(2+) bursts after the onset of heating and immediately after re-cooling. Cells were more thermosensitive at physiological (37°C) than at room (25°C) temperature; however, at 37°C, cells were responsive at a higher temperature (ambient temperature+heat pulse). These results strongly suggest that the heat pulse-induced Ca(2+) burst is caused by a transient imbalance in Ca(2+) flow between SERCA and IP3R, and offer a potential new method for thermally controlling Ca(2+)-regulated cellular functions.

  10. The Fourth SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-4)

    Science.gov (United States)

    Hooker, Stanford B.; Thomas, Crystal S.; van Heukelem, Laurie; Schlueter, louise; Russ, Mary E.; Ras, Josephine; Claustre, Herve; Clementson, Lesley; Canuti, Elisabetta; Berthon, Jean-Francois; hide

    2010-01-01

    Ten international laboratories specializing in the determination of marine pigment concentrations using high performance liquid chromatography (HPLC) were intercompared using in situ samples and a mixed pigment sample. Although prior Sea-viewing Wide Field-of-view Sensor (SeaWiFS) High Performance Liquid Chromatography (HPLC) Round-Robin Experiment (SeaHARRE) activities conducted in open-ocean waters covered a wide dynamic range in productivity, and some of the samples were collected in the coastal zone, none of the activities involved exclusively coastal samples. Consequently, SeaHARRE-4 was organized and executed as a strictly coastal activity and the field samples were collected from primarily eutrophic waters within the coastal zone of Denmark. The more restrictive perspective limited the dynamic range in chlorophyll concentration to approximately one and a half orders of magnitude (previous activities covered more than two orders of magnitude). The method intercomparisons were used for the following objectives: a) estimate the uncertainties in quantitating individual pigments and higher-order variables formed from sums and ratios; b) confirm if the chlorophyll a accuracy requirements for ocean color validation activities (approximately 25%, although 15% would allow for algorithm refinement) can be met in coastal waters; c) establish the reduction in uncertainties as a result of applying QA procedures; d) show the importance of establishing a properly defined referencing system in the computation of uncertainties; e) quantify the analytical benefits of performance metrics, and f) demonstrate the utility of a laboratory mix in understanding method performance. In addition, the remote sensing requirements for the in situ determination of total chlorophyll a were investigated to determine whether or not the average uncertainty for this measurement is being satisfied.

  11. Poultry Houses, WI Livestock Consortium Livestock Premises; confidentiality protected by law; use for animal health emergencies only; some aggregated county data, Published in 2009, 1:24000 (1in=2000ft) scale, Wisconsin Department of Agriculture, Trade & Consumer Protection.

    Data.gov (United States)

    NSGIC State | GIS Inventory — Poultry Houses dataset current as of 2009. WI Livestock Consortium Livestock Premises; confidentiality protected by law; use for animal health emergencies only; some...

  12. PENGARUH EKSTRAK PROPOLIS TERHADAP PENINGKATAN EKSPRESI p21, EKSPRESI PROTEIN Bax DAN INDUKSI APOPTOSIS PADA KULTUR SEL KANKER KOLON (CELL LINE WiDr

    Directory of Open Access Journals (Sweden)

    Didik Prasetyo

    2017-06-01

    Full Text Available Kanker kolorektal merupakan kanker ketiga terbanyak dengan lebih dari 1 juta kasus setiap tahunnya dan salah satu kanker dengan mortalitas tertinggi di seluruh dunia. Radioterapi dan kemoterapi pada kanker relatif terbatas karena toksisitasnya yang tinggi dan efek samping yang bersifat merusak. Pengembangan propolis merupakan strategi baru untuk terapi adjuvan yang diharapkan meminimalkan efek samping terapi standar yang ada. Peran propolis pada keganasan terkait kemampuannya dalam menginduksi apoptosis dan aktivitas antiproliferasi. Penelitian in vitro, menunjukkan propolis memiliki aktivitas proapoptosis pada berbagai jenis sel kanker, meliputi : kanker laring, kanker paru, kanker pankreas, kanker tiroid, kanker payudara, kanker prostat dan glioma. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian propolis yang berasal dari Kerjo, Karanganyar, Indonesia terhadap aktivitas antiproliferasi, terkait peningkatan ekspresi p21 dan induksi apoptosis terkait peningkatan ekspresi protein bax pada kultur sel kanker kolon (cell line WiDr. Jenis penelitian ini, eksperimental laboratorik dengan post test with control group design. Penelitian menggunakan kultur sel WiDr (sel kanker kolon dengan pemberian ekstrak etanol propolis (EEP. Pengamatan ekspresi p21 dan protein Bax dengan metode imunositokimia, sedangkan pengamatan induksi apoptosis dengan flowcytometry. Analisis statistik menggunakan uji Kruskall Wallis dilanjutkan Mann WhutneyU test. EEP cenderung menekan viabilitas sel WiDr dengan IC50 sebesar 140 μg/mL. EEP konsentrasi 70,140, 280 μg/mL mampu meningkatkan ekspresi p21 yang sebanding dengan peningkatan konsentrasi yang diberikan. EEP konsentrasi 70 μg/mL (1/2 IC50 paling efektif dalam menginduksi apoptosis dan meningkatkan ekspresi Bax pada sel WiDr. Peningkatan konsentrasi EEP mengakibatkan kematian sel WiDr ke arah nekrosis. Penelitian ini menunjukkan EEP mampu menekan viabilitas sel WiDr. Aktivitas ini kemungkinan terkait dengan

  13. Comparison of SeaWiFS and MODIS time series of inherent optical properties for the Adriatic Sea

    Directory of Open Access Journals (Sweden)

    F. Mélin

    2011-05-01

    Full Text Available Time series of inherent optical properties (IOPs derived from SeaWiFS and MODIS are compared for the Adriatic Sea. The IOPs are outputs of the Quasi-Analytical Algorithm and include total absorption a, phytoplankton absorption aph, absorption associated with colored detrital material (CDM acdm, and particle backscattering coefficient bbp. The average root-mean square difference Δ computed for log-transformed distributions decreases for $a$ from 0.084 at 412 nm to 0.052 at 490 nm, is higher for aph(443 (0.149 than for acdm(443 (0.071, and is approximately 0.165 for bbp at various wavelengths. The SeaWiFS a at 443 and 490 nm, aph at 443 nm and bbp are on average higher than the MODIS counterparts. Statistics show significant variations in space and time. There is an overall increasing gradient for Δ associated with the absorption terms from the open southern and central Adriatic to the northwest part of the basin, and a reversed gradient for the particulate backscattering coefficient. For time series analysis, only a(412 and acdm(443 currently present an unbiased continuity bridging the SeaWiFS and MODIS periods for the Adriatic Sea.

  14. Exposure to radio frequency electromagnetic fields from wireless computer networks: duty factors of Wi-Fi devices operating in schools.

    Science.gov (United States)

    Khalid, M; Mee, T; Peyman, A; Addison, D; Calderon, C; Maslanyj, M; Mann, S

    2011-12-01

    The growing use of wireless local area networks (WLAN) in schools has prompted a study to investigate exposure to the radio frequency (RF) electromagnetic fields from Wi-Fi devices. International guidelines on limiting the adverse health effects of RF, such as those of ICNIRP, allow for time-averaging of exposure. Thus, as Wi-Fi signals consist of intermittent bursts of RF energy, it is important to consider the duty factors of devices in assessing the extent of exposure and compliance with guidelines. Using radio packet capture methods, the duty factor of Wi-Fi devices has been assessed in a sample of 6 primary and secondary schools during classroom lessons. For the 146 individual laptops investigated, the range of duty factors was from 0.02 to 0.91%, with a mean of 0.08% (SD 0.10%). The duty factors of access points from 7 networks ranged from 1.0% to 11.7% with a mean of 4.79% (SD 3.76%). Data gathered with transmit time measuring devices attached to laptops also showed similar results. Within the present limited sample, the range of duty factors from laptops and access points were found to be broadly similar for primary and secondary schools. Applying these duty factors to previously published results from this project, the maximum time-averaged power density from a laptop would be 220 μW m(-2), at a distance of 0.5 m and the peak localised SAR predicted in the torso region of a 10 year old child model, at 34 cm from the antenna, would be 80 μW kg(-1). Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  15. Study on an Indoor Positioning System for Harsh Environments Based on Wi-Fi and Bluetooth Low Energy.

    Science.gov (United States)

    de Blasio, Gabriel; Quesada-Arencibia, Alexis; García, Carmelo R; Molina-Gil, Jezabel Miriam; Caballero-Gil, Cándido

    2017-06-06

    This paper presents a study of positioning system that provides advanced information services based on Wi-Fi and Bluetooth Low Energy (BLE) technologies. It uses Wi-Fi for rough positioning and BLE for fine positioning. It is designed for use in public transportation system stations and terminals where the conditions are "hostile" or unfavourable due to signal noise produced by the continuous movement of passengers and buses, data collection conducted in the constant presence thereof, multipath fading, non-line of sight (NLOS) conditions, the fact that part of the wireless communication infrastructure has already been deployed and positioned in a way that may not be optimal for positioning purposes, variable humidity conditions, etc. The ultimate goal is to provide a service that may be used to assist people with special needs. We present experimental results based on scene analysis; the main distance metric used was the Euclidean distance but the Mahalanobis distance was also used in one case. The algorithm employed to compare fingerprints was the weighted k -nearest neighbor one. For Wi-Fi, with only three visible access points, accuracy ranged from 3.94 to 4.82 m, and precision from 5.21 to 7.0 m 90% of the time. With respect to BLE, with a low beacon density (1 beacon per 45.7 m²), accuracy ranged from 1.47 to 2.15 m, and precision from 1.81 to 3.58 m 90% of the time. Taking into account the fact that this system is designed to work in real situations in a scenario with high environmental fluctuations, and comparing the results with others obtained in laboratory scenarios, our results are promising and demonstrate that the system would be able to position users with these reasonable values of accuracy and precision.

  16. Study on an Indoor Positioning System for Harsh Environments Based on Wi-Fi and Bluetooth Low Energy

    Directory of Open Access Journals (Sweden)

    Gabriel de Blasio

    2017-06-01

    Full Text Available This paper presents a study of positioning system that provides advanced information services based on Wi-Fi and Bluetooth Low Energy (BLE technologies. It uses Wi-Fi for rough positioning and BLE for fine positioning. It is designed for use in public transportation system stations and terminals where the conditions are “hostile” or unfavourable due to signal noise produced by the continuous movement of passengers and buses, data collection conducted in the constant presence thereof, multipath fading, non-line of sight (NLOS conditions, the fact that part of the wireless communication infrastructure has already been deployed and positioned in a way that may not be optimal for positioning purposes, variable humidity conditions, etc. The ultimate goal is to provide a service that may be used to assist people with special needs. We present experimental results based on scene analysis; the main distance metric used was the Euclidean distance but the Mahalanobis distance was also used in one case. The algorithm employed to compare fingerprints was the weighted k-nearest neighbor one. For Wi-Fi, with only three visible access points, accuracy ranged from 3.94 to 4.82 m, and precision from 5.21 to 7.0 m 90% of the time. With respect to BLE, with a low beacon density (1 beacon per 45.7 m2, accuracy ranged from 1.47 to 2.15 m, and precision from 1.81 to 3.58 m 90% of the time. Taking into account the fact that this system is designed to work in real situations in a scenario with high environmental fluctuations, and comparing the results with others obtained in laboratory scenarios, our results are promising and demonstrate that the system would be able to position users with these reasonable values of accuracy and precision.

  17. Effect of long-term exposure of 2.4 GHz radiofrequency radiation emitted from Wi-Fi equipment on testes functions.

    Science.gov (United States)

    Dasdag, Suleyman; Taş, Muzaffer; Akdag, Mehmet Zulkuf; Yegin, Korkut

    2015-03-01

    The aim of this study was to investigate long-term effects of radiofrequency radiation (RFR) emitted from a Wireless Fidelity (Wi-Fi) system on testes. The study was carried out on 16 Wistar Albino adult male rats by dividing them into two groups such as sham (n: 8) and exposure (n: 8). Rats in the exposure group were exposed to 2.4 GHz RFR radiation for 24 h/d during 12 months (1 year). The same procedure was applied to the rats in the sham control group except the Wi-Fi system was turned off. Immediately after the last exposure, rats were sacrificed and reproductive organs were removed. Motility (%), concentration (×10(6)/mL), tail defects (%), head defects (%) and total morphologic defects (%) of sperms and weight of testes (g), left epididymis (g), prostate (g), seminal vesicles (g) were determined. Seminiferous tubules diameter (μm) and tunica albuginea thickness (μm) were also measured. However, the results were evaluated by using Johnsen's score. Head defects increased in the exposure group (p  0.05). In conclusion, we observed that long-term exposure of 2.4 GHz RF emitted from Wi-Fi (2420 μW/kg, 1 g average) affects some of the reproductive parameters of male rats. We suggest Wi-Fi users to avoid long-term exposure of RF emissions from Wi-Fi equipment.

  18. Dynamic Power-Saving Method for Wi-Fi Direct Based IoT Networks Considering Variable-Bit-Rate Video Traffic.

    Science.gov (United States)

    Jin, Meihua; Jung, Ji-Young; Lee, Jung-Ryun

    2016-10-12

    With the arrival of the era of Internet of Things (IoT), Wi-Fi Direct is becoming an emerging wireless technology that allows one to communicate through a direct connection between the mobile devices anytime, anywhere. In Wi-Fi Direct-based IoT networks, all devices are categorized by group of owner (GO) and client. Since portability is emphasized in Wi-Fi Direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi Direct standard defines two power-saving methods: Opportunistic and Notice of Absence (NoA) power-saving methods. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi Direct power-saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the lengths of awake intervals in a beacon interval dynamically. In addition, considering the inter-dependency among video frames, the proposed algorithm ensures that a video frame having high priority is transmitted with higher probability than other frames having low priority. Simulation results show that the proposed method outperforms the traditional NoA method in terms of average delay and energy efficiency.

  19. Modeling of Wi-Fi IEEE 802.11ac Offloading Performance For 1000x Capacity Expansion of LTE-Advanced

    DEFF Research Database (Denmark)

    Hu, Liang; Sanchez, Maria Laura Luque; Maternia, Michael

    2013-01-01

    This paper studies indoor Wi-Fi IEEE 802.11ac deployment as a capacity expansion solution of LTE-A (Long Term Evolution-Advanced) network to achieve 1000 times higher capacity. Besides increasing the traffic volume by a factor of x1000, we also increase the minimum target user data rate to 10Mbit....../s. The objective is to understand the performance and offloading capability of Wi-Fi 802.11ac at 5GHz. For the performance evaluation of Wi-Fi, we propose a novel analytical throughput model that captures both key 802.11ac enhancements and multi-cell interference. We provide a quantitative evaluation of large......-scale indoor Wi-Fi 802.11ac deployment in a real urban scenario by extensive simulations. We conclude that deploying indoor Wi-Fi access points in almost every building is essential to carry the x1000 traffic volume and ensure a minimum user data rate of 10Mbit/s....

  20. Dynamic Power-Saving Method for Wi-Fi Direct Based IoT Networks Considering Variable-Bit-Rate Video Traffic

    Directory of Open Access Journals (Sweden)

    Meihua Jin

    2016-10-01

    Full Text Available With the arrival of the era of Internet of Things (IoT, Wi-Fi Direct is becoming an emerging wireless technology that allows one to communicate through a direct connection between the mobile devices anytime, anywhere. In Wi-Fi Direct-based IoT networks, all devices are categorized by group of owner (GO and client. Since portability is emphasized in Wi-Fi Direct devices, it is essential to control the energy consumption of a device very efficiently. In order to avoid unnecessary power consumed by GO, Wi-Fi Direct standard defines two power-saving methods: Opportunistic and Notice of Absence (NoA power-saving methods. In this paper, we suggest an algorithm to enhance the energy efficiency of Wi-Fi Direct power-saving, considering the characteristics of multimedia video traffic. Proposed algorithm utilizes the statistical distribution for the size of video frames and adjusts the lengths of awake intervals in a beacon interval dynamically. In addition, considering the inter-dependency among video frames, the proposed algorithm ensures that a video frame having high priority is transmitted with higher probability than other frames having low priority. Simulation results show that the proposed method outperforms the traditional NoA method in terms of average delay and energy efficiency.