Handheld Communication Devices Research Articles

Microfluidic SIW-Based Tunable Self-Diplexing Antenna for Sub-6 GHz Band Applications

This work introduces a novel frequency tunable self-diplexing antenna (SDA) design based on substrate integrated waveguide (SIW) technology. A modified A-shaped slot is employed on the cavity’s top plane, which is excited by two independent <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50~\Omega $ </tex-math></inline-formula> microstrip feed lines to operate at each resonant frequency. The frequency flexibility of the proposed antenna allows for fine-tuning at each resonance frequency. The frequency flexibility has been achieved by employing the substrate’s air- and liquid-filled pockets. The proposed antenna can be configured to operate in the 3.5-3.8 GHz and 5.53-6.2 GHz bands, as demonstrated by the simulation results. With distilled water-filled pockets, the proposed antenna offers peak gains of 5.04 dBi and 5.26 dBi. The proposed SDA exhibits competitive features such as a highly compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.22\lambda _{g} ^{2}$ </tex-math></inline-formula> and high isolation (>27dB), which makes it suitable for handheld communication devices. The simulated and measured circuit responses are in good agreement.

Protecting location privacy in cloud services

In GPS system enabled hand-held communication devices which works as a beacon that transmits our location. Also, the location-based services that emerged in recent years make use of location data. The location data provided to these location-based service providers have enough sensitive information to bother about. The location privacy became an area of concern in recent years. Developed and developing countries are now in process to make laws against the use of location information without the consent of the user or without legal warrant. Most of the research strategies proposed in recent years have one thing in common that we provide a region instead of exact coordinates of the location of the user. These attacks are called location dependent attacks or velocity linkage attacks in literature. We have in our effort proposed a solution to the problem of location privacy protection taking care of the location dependent attacks. We also keep in mind the fact that user is more concerned about his locations at certain places. We tested the proposed solution against requests issued by 5000 and 15000 users moving in a field of 10000x10000 units’ area.

Mobile Phones and Driving Offences: Contextualising the Need for Recent Legislative Changes

Keywords Road Traffic Act 1988, Road Vehicles (Construction and Use) Regulations 1986, mobile phone, driving offence, hand-held interactive communication device

Compact 4 × 4 Proximity Coupled Microstrip Fed UWB Stepped Slot MIMO Antenna Having Triple Band Rejection

The presented antenna is a novel highly isolated compact four-element Multiple Input Multiple Output (MIMO) antenna with common ground, which can reject three undesired bands effectively for Ultra-Wideband (UWB) Communication. The overlapping of narrowband communication systems with the UWB spectrum makes radio signals interfere. Therefore, the proposed antenna is designed with triple-band rejection capability. The antenna consists of four feedlines and a common ground surface which acts as the main radiator. The four elements of the antenna are kept orthogonally to exploit polarisation diversity, resulting in high isolation. The presented antenna is having size = 44 × 44 mm2 and printed on FR4 substrate. A spiral slot was introduced in the ground surface which behaves similarly as a band-stop filter (BSF) and rejects the X- band for Uplink Satellite Communication. For rejecting WiMAX and WLAN band, the modified trident shape of the microstrip line is used. Also, Defected Ground Structure (DGS) is used for the isolation (> 23 dB) enhancement. Simulation and measurement results are quite similar. The proposed antenna is used for small handheld communication devices.

Tele-healthcare and the use of virtual communication technologies in medical research and application: the future of telemedicine is now!

Contemporary world events are demonstrating the need to embrace and further develop tele-health options for assessment and delivery of biopsychosocial healthcare services. This is now possible, given advances in communication technologies allowing virtual connections of medical personnel with constituents, as well as necessary, in light of recent challenges posed by infectious conditions and growing needs for travel restrictions, social distancing, and isolation of large portions of populations. Moreover, the opportunity to virtually connect with persons through ubiquitous computer-based and handheld communication devices allows comprehensive care provision to include underserved areas, where restricted, walk-in access to brick-and-mortar establishments has long been recognized as a limiting factor in healthcare. This review examines evolving approaches of tele-healthcare, with a specific focus on telemedicine as a bridge between traditional, in-person approaches to diagnose and treat medical conditions and new healthcare opportunities developing to meet changing societal needs. The three purposes of the review are: discuss background information, with a brief look at policy and procedure guiding applications of tele-techniques in healthcare practices; identify relevant scientific studies to show the breadth of new evidence-based research for telemedicine practices; and, discuss challenges for the further development of telemedicine as healthcare systems in the United States evolve to meet current and projected healthcare needs.

Mobile phones and "inattention" injuries: the risk is real.

Mobile phones though indispensable have a flip side: in fact, they adversely affect our ergonomics and mobility. They share an etiologic burden on the changed profile of inattention injuries; and now have proven to be a necessary evil in the changing lifestyles. We aimed to evaluate the role of mobile phones as a causative factor in these head and neck injuries. We evaluated various injury statistics published throughout the world that attributed the concurrence of neurological injuries to portable handheld communication devices. We evaluated the dangers posed by simultaneous engagement on phone and mobility and examined the impact on walking and field of view. We have also reviewed the current management strategies to combat this new mode of injury. The recent sensation Pokémon Go has been discussed as a case study of a spike in the incidence of injuries due to mobile phone use. Age >35 years old is a risk factor for mobile phone use and injuries as they have a higher chance of being distracted (81%) when compared to millennials (70% distracted). The highest incidence was that of head injuries being 33.1% of the estimated total followed by face, including eyelid, eye area, and nose (32.7%); and neck (12.5%). The most common injury diagnoses included laceration (26.3% of estimated total), contusion/abrasion (24.5%), and internal organ injury (18.4%). A heightened sense of self-protection and a multitasking attitude remains at the core of the trouble despite having knowledge of the required behavior. The health hazard of mobile phone use driving or walking needs to be highlighted with special emphasis on public education, law adherence, and technological solutions to mitigate the risk. The onus lies on the public as any technological advance would only work on the multitasking strategy and the price would be paid by the vulnerable road users.

A Low-Profile Wideband Antenna for WWAN/LTE Applications

In this paper, a low-profile antenna is presented for wideband communication applications. The presented design consists of an I-shaped driven strip and a rectangular ground strip with an open slot in the middle and a steeped lower portion. The measured results demonstrate that the achieved operating band of the proposed antenna has the potential to cover Globalstar satellite phones (GSSP) (1.61–1.63 GHz, uplink), advanced wireless systems (1.71–1.76 GHz, 2.11–2.17 GHz), DCS (1710–1880 MHz), GSM (1800MHz), DCP (1.88–1.90 GHz), DCS-1900/PCS/PHS (1850–1990MHz), WCDMA/IMT-2000 (1920–2170MHz), UMTS (1920–2170 MHz) and long-term evolution (LTE) bands (FDD LTE bands 1–4, 9–10, 15–16, 23–25, 33–37, 39). The designed antenna possessed a very small size of 0.35λ0 × 0.027λ0 at the lowest frequency (S11 ≤ −10dB), achieved good gains and exhibited stable radiation patterns, which makes it suitable for handheld communication devices.

Multivariate dynamic Tobit models with lagged observed dependent variables: An effectiveness analysis of highway safety laws

Highway safety laws aim to influence driver behaviors so as to reduce the frequency and severity of crashes, and their outcomes. For one specific highway safety law, it would have different effects on the crashes across severities. Understanding such effects can help policy makers upgrade current laws and hence improve traffic safety. To investigate the effects of highway safety laws on crashes across severities, multivariate models are needed to account for the interdependency issues in crash counts across severities. Based on the characteristics of the dependent variables, multivariate dynamic Tobit (MVDT) models are proposed to analyze crash counts that are aggregated at the state level. Lagged observed dependent variables are incorporated into the MVDT models to account for potential temporal correlation issues in crash data. The state highway safety law related factors are used as the explanatory variables and socio-demographic and traffic factors are used as the control variables. Three models, a MVDT model with lagged observed dependent variables, a MVDT model with unobserved random variables, and a multivariate static Tobit (MVST) model are developed and compared. The results show that among the investigated models, the MVDT models with lagged observed dependent variables have the best goodness-of-fit. The findings indicate that, compared to the MVST, the MVDT models have better explanatory power and prediction accuracy. The MVDT model with lagged observed variables can better handle the stochasticity and dependency in the temporal evolution of the crash counts and the estimated values from the model are closer to the observed values. The results show that more lives could be saved if law enforcement agencies can make a sustained effort to educate the public about the importance of motorcyclists wearing helmets. Motor vehicle crash-related deaths, injuries, and property damages could be reduced if states enact laws for stricter text messaging rules, higher speeding fines, older licensing age, and stronger graduated licensing provisions. Injury and PDO crashes would be significantly reduced with stricter laws prohibiting the use of hand-held communication devices and higher fines for drunk driving.

The Challenges of Measuring Integrated Antennas at Millimeter-Wave Frequencies [Measurements Corner

The increasing demand for radar sensors and the wide distribution of handheld communication devices push the development of low-cost components with a small form factor. One approach to achieve smaller, low-cost devices is the integration of the required components on a monolithic microwaveintegrated circuit (MMIC). At frequencies above 100 GHz, passive components are small enough to be integrated onto a chip, and the advances in semiconductor technology make it possible to build active components that can operate at millimeter (mm)-wave frequencies [1], [2]. The available bandwidths of several gigahertz at mm-wave frequencies offer high data rates for communication devices or high resolution for remote-sensing applications. By integrating the radio-frequency (RF) components and the antennas, lossy off-chip transitions can be avoided, thus limiting the required connections to the power supply and baseband signals.

Design and development of a stacked complementary microstrip antenna with a “π”-shaped DGS for UWB, UNII, WLAN, WiMAX, and Radio Astronomy wireless applications

The proposed research paper presents the design, development, and experimental testing of a broadband stacked complementary microstrip antenna for ultra-wideband (UWB) (5.28–5.85 GHz), Unlicensed National Information Infrastructure band (UNII) (5.25–5.825 GHz), wireless local area networks (WLAN, IEEE802.11a, 5.15–5.35 GHz), and IEEE 802.11b (5.75–5.85 GHz), Worldwide Interoperability for Microwave Access band (5.25–5.85 GHz), and Radio Astronomy band (6.6–6.75 GHz) wireless applications. The main aim of this paper is to obtain an UWB behavior from the combined effect of two resonances exhibited by the driven and parasitic patches of a stacked complementary antenna geometry. Circularly polarized radiations are also emitted by the antenna by the addition of an orthogonal stub to its feed line. The proposed three-layered antenna structure (without air gap) is fabricated on commercially available glass-reinforced epoxy laminate, FR4 substrate. The topmost layer of FR4 has a square-shaped patch parasitic patch printed over it; this patch has a square slot etched out from it. The middle layer of the antenna has a square-shaped driven patch of approximately the same dimensions as that of the slot in parasitic patch. The antenna is fed using aperture-coupled feeding mechanism. Therefore the lowermost layer of FR4 has a ground plane on its top with a “π”-shaped slot etched from it and a feed line with an orthogonal stub at its bottom forming a “T”-shaped geometry. The antenna is fed by the electromagnetic coupling between the antenna layers .The proposed antenna has a compact structure with overall volumetric dimensions of 4.7 × 3.82 × 0.483 cm3. The antenna design and simulations are carried out using CSTMWSV'10 with perfect boundary (electric and magnetic) estimations. This designed antenna shows an UWB behavior from 5.14 to 5.85 GHz with an impedance bandwidth of 710 MHZ and a fractional bandwidth of 12.62% at the center frequency of band at 5.5 GHz. The radiating antenna also possesses a good gain of 4.59 dBi at the central frequency of 5.50 GHz and a 1 dB axial ratio bandwidth of 820 MHz from 5.16 to 5.98 GHz. The validation of results is done by fabrication and experimental testing of the antenna using a vector network analyzer and placing the antenna in an anechoic chamber for gain measurements. The measured results show close matching with the simulated ones and this makes the antenna well suited for the proposed wireless applications of interest, specifically in small handheld wireless communication devices.

New Compact Microstrip Patch Antennas: Design and Simulation Results

Objectives: To design new multi-band antennas based on patch resonator with comparative results to each other. Both antennas are compact in size and have high quality responses which can be applied in many handheld and personal communication devices. Methods/Analysis: New microstrip patch antennas based on modified first iteration of Minkowski fractal geometry and applying central small square cut in the main resonator have been presented in this paper with and without inserting corner square patches. Both antennas have designed using single layer and dual feeds to operate as multi frequency devices. The antennas have been modeled and optimized by using the Microwave Office (MWO) simulator based on the method of moments. The projected antennas have been designed using FR4 substrate with a relative dielectric constant of 4.4 and a substrate height of 1.6 mm. Compared with the microstrip patch antenna without inserting corner patches using same main patch resonator dimensions and substrate specifications, the designed antenna with corner patches exhibits more operational frequencies as well as as greater frequency ratios with respect to the first fundamental frequency. Findings: New microstrip antennas based on patch resonator with and without inserting corner patches have been proposed. The first antenna exhibits multi-frequency behavior, where resonances appear to take place at frequencies of 2.49, 3.03and 6.63 GHz, within 2 to 7 GHz frequency range. The second antenna exhibits a higher number of resonant frequencies that appear at 2.14, 2.55, 5.03, 5.81, 5.9 and 6.14 GHz respectively under same previous frequency range. The first three operational frequencies have decreased or shifted by inserting corner square patches due to increased electrical physical dimensions of the second antenna. Also, these corner patches act as EM perturbation elements to stimulate the second antenna with more resonant frequencies within 2-7 GHz frequency sweeping range. Theoretically, there is an important relation between antenna dimensions and guided wavelength. This relation specifies if antenna dimension is less than quarter guided wavelength (λg), then the antenna is impractical because radiation resistance, bandwidth and gain are decreased and therefore the antenna size is enlarged. By the way, the dimensions of Antennas 1and 2 have been found to be (0.259 λg x 0.259 λg) and (0.269 λg x 0.269 λg) respectively according to their fundamental frequencies which are satisfactory. Both antennas have small sizes and high quality responses which can be applied in many handheld and personal communication devices. Novelty/Improvement: In this paper, new multi-band antennas based on patch resonator have been proposed. The proposed resonators have been initiated from the transformed version of the first iteration of Minkowski fractal geometry. These antennas have compact dimensions with good return loss and radiation pattern performances which are desired features to be adopted in many communication devices

A Low Complexity Direction Finding System Based on a Six-Port Integrated MIMO Antenna System

In this paper, a low complexity microwave based direction finding (DF) system is presented. The proposed system consists of single six-port (SP) circuit integrated with a reconfigurable multiple-input-multiple-output (MIMO) antenna system. The proposed design is a complete integrated solution with DF capabilities for cognitive radio platforms. The design is suitable to be used in compact wireless handheld and mobile communication devices. The SP circuit covers a wide frequency band (1.68∼2.25 GHz) while the reconfigurable MIMO antenna system cover several frequency bands between 0.7 GHz to 3 GHz. The fabricated integrated system achieves ±16° accuracy in its direction of arrival estimates.

Media Management in a Small Polity: Political Elites’ Synchronized Calls to Regional Talk Radio and Attempted Manipulation of Public Opinion Polls

Little is known about how elected representatives attempt to manipulate public opinion and news media through their participation on regional open line radio or media straw polls. This article examines the systematic attempts by political actors to engage these media in the small polity of Newfoundland, Canada, where politics is characterized by the hyper-local nature of 590-VOCM radio programming. Our mixed-method study draws from talk radio call-in logs, online straw poll vote results, observation of the production of open line programming, and insights from local media personnel. We draw attention to two clandestine media management techniques. First, we analyze call-ins by elected legislators to talk radio that were timed to coincide with the known field dates of a public opinion polling company. Second, we report that handheld communication devices were used by senior members of the governing party to mobilize legislators and party personnel to repeatedly vote on straw polls on regional media Web sites. Our findings show that there is a substantial and statistically significant increase in the probability that legislators will call talk radio when pollsters are in the field. Furthermore, we document and explore the manner in which political elites mobilize to engage online media straw polls, and discover that straw poll questions which address political topics attract a disproportionately higher number of “votes” than nonpolitical questions. This micro-level study offers perspective for interpreting macro-level knowledge about political talk radio, horse race/game and strategic media frames, and about political elites’ mobilization and media management tactics.

A Comparison of Two Methods to Assess the Usage of Mobile Hand-Held Communication Devices

The purposes of this study were to: 1) examine agreement between self-reported measures of mobile device use and direct measures of use, and 2) understand how respondents thought about their device use when they provided self-reports. Self-reports of six categories of device use were obtained using a previously developed questionnaire, and direct measures of use were collected using a custom logging application (n = 47). Bland-Altman analyses were used to examine agreement between the two measurement approaches. Interviews targeted participants’ experiences completing the device use section of the questionnaire. Self-reports of use on a typical day last week overestimated logged use. Overestimates tended to be low at low average usage times, and became more variable as usage time increased. Self-reports of use yesterday also exceeded logged use, however the degree of overestimation was less than for a typical day last week. Six themes were identified from interviews, including the thought process used by participants to arrive at usage and the ease of reporting usage. It is challenging for respondents of this questionnaire to provide accurate self-reports of use. The source of this challenge may be attributed to the intrinsic difficulty of estimating use, partly due to the multiple functions of the devices as well as the variability of use both within a day and a week. Research investigating the relationship between device use and health outcomes should include a logging application to examine exposure simultaneously with self-reports to better understand the sources of hazardous exposures.

Dual-Element PIFA Design with Dual Shorting Pins for Multiband Communication Devices

A low profile multiband resonant, dual-element array antenna is proposed for use in handheld communication devices. The proposed antenna comprises two dual shorting pin planar inverted-F antennas and a folded ground plane which operates as a perfect electric conductor case. The feeding scheme adopted for the proposed design produces a fixed phase difference between two antenna elements of the design to achieve an ultrawide bandwidth and a flexible radiation pattern. The proposed antenna design is simulated with commercially available software, which is based on the finite element method. The resonant frequency bands covered are GSM850/900, DCS1800, PCS1900, UMTS2100, and LTE2300/2600 MHz. Details of the design considerations for the proposed antenna are described and the simulated and measured results are presented and discussed, which are in agreement.

Three-dimensional-positioning based on echolocation using a simple iterative method

This paper describes a method for determining the position of an object in three dimensions using time-of-flight (TOF) echolocation. The position is computed using a one-bit cross correlation and requires less computation time than a general cross correlation. A delta-sigma modulation board is introduced to convert the echo signal into one-bit signals. This solution uses an iterative method, i.e., Newton–Raphson, to obtain a position estimate. Additionally, an initial value for the solution is obtained by averaging TOFs, and no guess is required. Three hand-held communication devices are adapted as acoustical receivers. The validity of the proposed method is verified by the repeatability of the experimental results.

Warpage control of thin-walled injection molding using local mold temperatures

Currently, 3C products are required to be lightweight, portable, and convenient. Injection molding is among the most used techniques for mass production in plastic processing industries; however, producing thinner parts that do not warp is challenging. Although plastic components warp for numerous complicated reasons, warpage primarily is caused by variations in shrinkage during the injection process of plastic part manufacturing. Material properties, part design, mold design, and processing conditions are factors influencing variations in the part shrinkage. For example, inconsistent thickness in component geometry, poor sprue–runner–gate or cooling design in the injection mold, and improper molding condition settings may cause plastic parts to warp excessively. Warpage causes unpredictable component shapes, which may cause poor assembly quality. Although mold cooling achieved by adjusting mold temperatures improves warpage, the conventional single mold temperature setting for each male or female mold plate limits the cooling capability. Therefore, this paper describes local mold temperature settings for a cooling system that can prevent severe warpage in an asymmetric plastic cover for handheld communication devices. The neutral axis theory is introduced to analyze the temperature distribution in the cross section of a part, and then predict the warping trend. Through simulation and experiments conducted in this study, the feasibility of using an effective local mold temperature setting in a cooling system to reduce part warpage was verified.

Quad Band Planar Inverted F Antenna for Smart Phone

In recent years, the demand for compact handheld communication devices has grown significantly. For device miniaturization antenna size is to be reduced. Micro strip and PIFA have been used for past few years. Since it has low profile geometry it can be embedded into devices. This project is to develop a Quad band small size Planar Inverted F Antenna (PIFA) for the operation in modern multi-band mobile transceiver system. Various techniques for analysis and design of such antenna investigated in this project. The design curve is used to design Quad band Planar inverted F Antenna to operate at the 900, 1800, 2100 and 3500 MHz bands. Since High Frequency Structure Simulator (HFSS) simulation result agrees well with the theoretical predictions, this project also designed through HFSS. An antenna designed at the four desired band and optimized to adjust the four resonance frequencies using HFSS simulation. The substrate FR4 (εr=4.4 &amp; tanδ = 0.02) are in good agreement with the simulation result. Further bandwidth enhancements by making defects in the substrate at particular area were need of much reflection.

Multishorting Pins PIFA Design for Multiband Communications

A novel PIFA model with multiple shorting pins is proposed for multiband, low profile wireless applications, which has the ability to work in adverse conditions. The proposed model has a planar radiating sheet, a ground plane, and sides covered with PEC boundaries. The substrate inside theantenna boxis tempered in order to improve the bandwidth and gain. The enhancements applied to the proposed PIFA model show improved characteristics for this PIFA model and make it a versatile candidate for handheld, low profile, and multiband resonant communication devices. Pertinent communication devices are those that work with GSM 850/900, UMTS 850/900/1700/1900/2100, LTE 2300/2500, and ISM 2400 bands used for Bluetooth and WLAN.

Nurse Leaders and the Use of Social Media: Becoming Literate to Lead

Social Media, whether it be Facebook, Twitter, LinkedIn, or any other web-based group with which one may associate for the purpose of communicating with members, is now ingrained in our culture. Recent surveys showed that 60% of people in the world are actively using text technology—the ability to send short, written messages to either individuals or groups, primarily from handheld communication devices—and that over 193,000 text messages are sent every second. Texting is the most used data service in the world. 1 Burrus D Better results using text messaging to dramatically improve your marketing efforts. May 2, 2013. LinkedIn. http://bigthink.com/flash-foresight/better-results-using-text-messaging-to-dramatically-improve-your-marketing-efforts Google Scholar Even more telling is the fact that 48% of all adults use social networking sites such as Facebook or Twitter, and that such use accounts for a quarter of all time spent on the internet. 2 Chinn T How nurses can use social media professionally. Nursing Times. July 13, 2012; (Accessed May 31, 2013.)http://www.nursingtimes.net/nursing-practice/clinical-zones/management/how-nurses-can-use-social-media-professionally/5047059.article Google Scholar Yet many healthcare organizations either fail to have any official policy regarding the use of social media or are tied to guidelines that fail to acknowledge the realities of this cultural shift and try to limit or prohibit this form of communication. Social Media, whether it be Facebook, Twitter, LinkedIn, or any other web-based group with which one may associate for the purpose of communicating with members, is now ingrained in our culture. Recent surveys showed that 60% of people in the world are actively using text technology—the ability to send short, written messages to either individuals or groups, primarily from handheld communication devices—and that over 193,000 text messages are sent every second. Texting is the most used data service in the world. 1 Burrus D Better results using text messaging to dramatically improve your marketing efforts. May 2, 2013. LinkedIn. http://bigthink.com/flash-foresight/better-results-using-text-messaging-to-dramatically-improve-your-marketing-efforts Google Scholar Even more telling is the fact that 48% of all adults use social networking sites such as Facebook or Twitter, and that such use accounts for a quarter of all time spent on the internet. 2 Chinn T How nurses can use social media professionally. Nursing Times. July 13, 2012; (Accessed May 31, 2013.)http://www.nursingtimes.net/nursing-practice/clinical-zones/management/how-nurses-can-use-social-media-professionally/5047059.article Google Scholar Yet many healthcare organizations either fail to have any official policy regarding the use of social media or are tied to guidelines that fail to acknowledge the realities of this cultural shift and try to limit or prohibit this form of communication.