On-the-move Research Articles

On the Move in the community: Protocol for a hybrid 1 trial examining effectiveness and fidelity of a community-based group exercise program for older adults

On the Move (OTM), a group exercise program to improve mobility in older adults, is efficacious when delivered by research staff. The next step in the development of OTM as a fully implementable intervention is to conduct an effectiveness study in which the intervention is delivered in community settings by community providers. We describe the methods of a hybrid 1 cluster randomized, single-blind, intervention trial to compare the effectiveness of OTM to a delayed intervention control in 502 community-dwelling older adults across 44 sites. OTM classes are taught by certified instructors in the community twice a week for 12weeks. Control centers receive no intervention for the first 12weeks followed by 12-weeks of OTM classes. Participants are assessed at baseline, 12 and 24weeks. The primary outcome is gait speed. Intervention fidelity, measured by adherence and competence in intervention delivery, is assessed by review of instructor intervention diaries and observation. Organizational, instructor, and participant-level factors which may impact fidelity are assessed using questionnaires, focus groups, and structured interviews. The findings of this trial will 1) establish the effectiveness of OTM on improvements in walking and post-intervention persistence of benefits, 2) assess intervention fidelity and identify the impact of organizational, instructor, and participant level factors on fidelity, and 3) determine the extent to which fidelity moderates the effectiveness of OTM. The information derived from this project will provide valuable insight into the real-world effectiveness of OTM as a health promotion program for improving mobility in older adults.

A Case Study on the Monitor Mode Passive Capturing of WLAN Packets in an On-the-Move Setup

Monitor mode packet capturing of WLAN is used to derive Access points and devices in the range for localization or occupancy purposes. The general modality of capturing and analysis in almost all available studies is to capture packets by being static (STT) at a location and indoors. In STT mode, the beacon and probe packets extract insights about the localization of devices and occupancy estimation. We propose scanning a predetermined path in an urban locality on the move (OTM) using monitor mode WLAN packet capturing. We also propose that in OTM, devices (STA) and Access Points (APs) can be traced from other packets like CTS, ATS, and ACKs apart from beacons and frames. We performed a case study of monitor mode packet capturing in an on-the-move and outdoor setup. The primary focus of the study was to validate the OTM modality and the methodology of detecting devices and APs. We studied all the packet types that were captured, including Beacons and Probes. The sensed devices and APs counts using probe and beacon packets were compared with the sensed devices, and APs counts using the new methodology. We found that considering other packets helps detect a more significant number of devices and APs. We also found that channel hoping strategy plays an essential role in maximizing the sensed items. The overall exercise revealed that the air is full of WLAN/Wi-Fi traffic, and using OTM can assimilate lots of valuable data and generate relevant information for various purposes. Essentially, on-the-move outdoor capture setups can be used to produce Wi-Fi access points and user devices related heat maps of the scanned locations. This can be useful in many governance and related matters. Briefly, we put forward an application architecture for the same.

On-The-Move Measurement Analysis for Ka-Band High Throughput Satellite and LiFi Communication Networks in Tropical Region

With the point in evaluating the performance of the On-the-Move (OTM) Satellite Communication and Light Fidelity (SatCom-LiFi), an extensive study of measurement has been conducted to give a wide vision of the SatCom-LiFi potential under a tropical region. As the interest for OTM network connectivity to offload the C-band capacity arises due to frequency spectrum scarcity, satellite networks offer to balance topographical requirements under tropical environment as the Next Generation Networks (NGN) trend for OTM communication system solutions. To date, mobile satellite terminal propagation model was carried out at temperate regions where further experimental measurement is needed under the OTM scenario in tropical region. This paper discusses on the areas where there are limited real-time data under the OTM scenario (e.g. rain attenuation, power arch) at Ka-band frequency. Integration infers, to be specific, the use of new elements capable in providing performance analysis of all systems involved and to take possible decision, in determining the need for a technically feasible solution. Measurement results reveal that, throughput data rate of 15 Mbps were able to be delivered for more than 80% of the time under the speed of 150 km/h with shielded mesh antenna. In addition to that, this paper reveals the favorable circumstances and inadequacies of OTM network quality, in which the measurement presented plays an important role for future researchers in distinguishing highly accurate predictions.

Effect of Community-Based Group Exercise Interventions on Standing Balance and Strength in Independent Living Older Adults.

Many interventions to improve mobility in older adults often include exercises to address underlying impairments such as strength deficits. Task-oriented exercise interventions that focus more on walking and stepping tasks that may be encountered in the community have been considered for improving mobility in older adults. The main purpose was to examine the effect of task-oriented and impairment-based group exercise interventions on standing balance and lower extremity muscle strength. This is an ancillary study to a cluster-randomized clinical trial. Participants included 107 older adults. Participants were randomized by facility to 1 of 2 different interventions, or a waitlist control group. The On the Move (OTM) task-oriented intervention consisted of warm-up, timing and coordination (stepping and walking patterns), strengthening, and stretching exercises. The standard of care impairment-based exercise intervention (STD) consisted of warm-up, strength, endurance, and stretching exercises. Postural sway and balance measures were recorded before and after the 12-week interventions. An accelerometer was used to collect postural sway for 6 different standing balance conditions. A portable load cell was used to assess lower extremity muscle strength for 3 muscle groups. The OTM group had a significant reduction in sway acceleration during most of the balance conditions over the 12-week period, whereas the STD had smaller, nonsignificant reductions. Both exercise interventions had a significant reduction in sway compared with the waitlist control group in at least 1 balance condition. The OTM and STD groups had significant increases in hip abduction strength during the intervention and the STD group also had an increase in knee extension strength. The waitlist group had a significant reduction in strength in all muscle groups during the 12-week period. Strength changes in both exercise groups were significantly different from the waitlist group but not from each other. Both exercise intervention groups had an improvement in standing balance and lower extremity strength when compared with a waitlist group that did not receive exercise. Although the exercise groups did not significantly differ from each other, the OTM exercise group showed a trend toward improvement in static standing balance conditions.

Hybrid Beam Steerable Phased Array Antenna for Satcom OTM with 16 GHZ Feed Signal

Now a day there is a great demand for communication On the Move (OTM). OTM antenna is system which is mounted on a vehicle such as boat, train, car, flight, and this system is used to track the satellite link and maintain the link between the terminal and satellite even when the vehicle is moving. The antenna always steer to track the satellite link while motion. Phased array antenna with hybrid beam steering method is proposed in this paper to achieve effective communication. The beam Formed in phased array of 100 isotropic elements has a wide beam width. But, to fetch satellite communication applications, the beam width a narrow beam width is required. Hence a parabolic reflector is chosen to sharpen the beam. But, for the ease of simulation, in place of the array of antennas, a horn antenna design to operate at the same operating frequency, 16 GHz is given as a feed to the reflector antenna and the simulation is done using HFSS.

Motor Control-based Group Exercise: Can It be Delivered as Effectively by Lay Leaders?

On the Move (OTM), a motor control-based group exercise program for community-dwelling older adults, has produced greater gains in mobility than a standard group exercise program when delivered by research leaders. The purposes of this study were:1) to examine the effectiveness of OTM versus a standard program when delivered by lay leaders and 2) to compare the outcomes of OTM when delivered by research versus lay leaders. Community-dwelling, medically stable older adults who could walk household distances participated. OTM consisted of warm-up, timing and coordination, strengthening, and stretching exercises. The seated standard program consisted of warm-up, aerobic, strengthening and stretching exercises. The primary outcome(s) of function and disability was the Late Life Function and Disability Instrument (LLFDI), and for walking ability were the Six Minute Walk Test and gait speed. 126 participants (mean age = 80.7±7.8 years, gait speed = 0.91 m/s) were randomized to OTM (n=49) or standard (n=77) programs. When taught by lay leaders, there were no significant between-intervention group differences in any of the outcomes (p>0.10). Comparing OTM outcomes between leaders, there was a statistical but not clinically meaningful difference in LLFDI disability (1.87±0.89, p=0.04) when taught by research versus lay leader, and moderate differences (p=0.06) in LLFDI overall function (1.89±1.02) and gait speed (0.05±0.03). Qualitative interview responses suggest that instructor-related concerns may have impacted program outcomes. When delivered by lay leaders OTM was not more effective than a standard program for improving function, disability, and mobility in older adults. Health promotion programs designed to improve mobility in community-dwelling older adults and based on a motor control theoretical background, may be best taught by rehabilitation professionals.

Low-Profile Two-Arm Inverted-L Antenna Design for Vehicular HF Communications

Design of an electrically small, low-profile vehicular on-the-move (OTM) wideband high frequency antenna with 24 kHz instantaneous-tuned bandwidth is discussed for near vertical incidence skywave (NVIS) communications. Improvement in performance is obtained by applying multiarming and offset feed antenna modifications. These allow for attaining the desired gain >−20 dBi at 3 MHz with a lower profile compared to traditional OTM 3 kHz bandwidth antennas. Specifically, the addition of the second arm improves the bandwidth, whereas NVIS gain is enhanced by offset feeding. The electrical dimensions of the proposed two-arm design over the platform are $\lambda /13 ~(\text {L}) \times \lambda /30 ~(\text {W}) \times \lambda /400$ (H) at the lowest frequency of operation. Antenna performance and achieved benefits under the condition of mechanical breakdown are also discussed. The scaled prototype of the proposed antenna mounted on a selected vehicular platform is built using additive manufacturing. Measurement results agree well with simulations thereby verifying the design procedure and all the discussed findings.

Wide-Band High-Frequency Antennas for Military Vehicles: Design and testing low-profile half-loop, inverted-L, and umbrella NVIS antennas

The design of low-profile, wide-band (WB), high-frequency (HF), vehicular, on-the-move (OTM) antennas is associated with a number of challenges, including their small electrical size, mounting constraints, and the diverse environment in the near field, to name a few. This article considers antennas for near vertical incidence skywave (NVIS) operation from 2 to 15 MHz with a wide tunable bandwidth of at least 24 kHz. The minimum gain at the zenith of -25 dBi is comparable to that of state-of-the-art 3-kHz channel OTM NVIS antennas. The baseline configuration is a two-arm half loop operating in NVIS mode, designed such that it can be easily reconfigured into either an inverted-L or an umbrella-loaded monopole. Each arrangement has its own advantages in terms of radiation patterns, impedance, and practicality. Two arms are used to satisfy the performance requirements and keep the overall profile under 1 m. A full-scale prototype is fabricated and integrated with a specific military vehicle. The stand-alone measurements confirm the expected impedance behavior, whereas the tests with an experimental WB HF radio prove the validity of the design approach. Because of the diverse operation modes, the antenna is flexible and can readily adapt to various communication conditions.

'And When a Worker's Not Working?' Income Security (Welfare and Pensions) for Mobile Workers in Canada

In this paper, we provide a basic overview of the welfare and pension income security options available to workers who are (or have been) on the move (OTM) in Canada. Workers on the move, for the purposes of this paper, include: (a) a Canadian or permanent resident worker who is working and living temporarily outside of their usual or current province of residence; (b) a Canadian or permanent resident worker who has recently worked and lived temporarily outside of their current province of residence; (c) a temporary foreign worker (TFW) who was employed under a valid work permit; (d) an undocumented worker who has worked without a valid work permit. We look at the legislative frameworks and the limited academic literature that address the eligibility for and practical access to income security benefits for such workers. This paper is divided into three parts: access to welfare benefits; access to public pensions (i.e. Old Age Security (OAS), Guaranteed Income Supplement (GIS) and the Canada and Quebec Pension Plans (CPP/QPP); and, finally, access to private pensions. In each section, we summarize eligibility issues for different categories of OTM workers in a table and, when appropriate, offer a breakdown of provincial-specific information for Newfoundland and Labrador, Quebec, Ontario, Alberta and British Columbia. Academic literature on this topic is nearly nonexistent, so our presentation and analysis remains rather technical. Overall, our conclusions are that, while immigration status makes TFWs and undocumented workers ineligible for some of these income security measures (a fact that may lead them into extreme financial hardship), the fact of a worker being “on the move” does not in and of itself seem to be a significant barrier to access. And while empirical research conducted by other members of the OTM team may uncover examples of mobile workers having difficulty accessing welfare or pensions in practice because of their mobile work trajectories or because of their lack of knowledge about their entitlement to these benefits, our research does not suggest that there are significant policy barriers related to being on the move.

On the Design of Vehicular Electrically Small Antennas for NVIS Communications

Design of low-profile vehicular on-the-move (OTM) wideband high-frequency (HF) antennas with 24-kHz instantaneous bandwidth for near-vertical communications is discussed. It is shown that multiarming significantly reduces the minimum antenna height, whereas the two-arm configuration is a tradeoff between antenna complexity and performance. A procedure for determining the minimum antenna height when the tuner loss is considered as a design parameter is introduced. The design evolves from a state-of-the-art magnetic dipole to a wire two-arm half-loop antenna (HLA). The profile for the amphibious assault vehicle (AAV) mounted antenna is 0.65 m ( $\lambda/230$ at 2 MHz) for the parabolic shape and 0.50 m ( $\lambda/300$ ) for the rectangular shape two-arm half-loop. The length of antenna base is 4.8 m ( $\lambda/31$ ) and the width is 3.3 m ( $\lambda/45$ ). A simple two-element tuner is considered in the scope of the results validation, along with the impedance and directivity patterns measurements on scaled 1/500 models.

Ka 대역 다중모드 모노펄스 추적 시스템을 위한 한 쌍의 슬롯(Slot)을 갖는 모드커플러 설계

OTM(On-The-Move) 위성통신 시스템은 차량에 탑재되어 고속 주행하거나 요동이 심한 지역을 주행하면서 위성 통신 링크를 안정적으로 유지하여야 한다. 따라서 열악한 환경에서도 정밀 추적이 가능하고, 차량에 탑재할 수 있도록 소형/경량화된 위성 추적 시스템이 필요하다. 2개의 슬롯(slot)으로 구성된 단일 모드 커플러를 사용하여, 원형 편파 특성을 이용하여 하나의 물리적 채널로 상하, 좌우 2개의 차신호를 동시에 비콘 수신기까지 전달하는 방안을 제안하고, 측정된 추적 오차신호를 제시한다. The main mission of OTM(On-The-Move) satellite communication system is to provide satellite communication service while moving on a vehicle. So it should have a capability to maintain a reliable communication channel when it travels at high speeds or in a severe fluctuation region. This paper presents a small-sized multi-mode monopulse structure applicable to OTM satellite communication system which has only single mode-coupler with a pair of slot using a feature of circular polarized received signal. And tracking error signal is defined using fundamental and high-order modes.

OTM(On-The-Move) 위성 통신 시스템을 위한 저잡음 증폭기 출력채널 단일화 구조 및 위상보정 방안

In this paper, a double-input single-output architecture of a LNA(Low Noise Amplifier) is presented to enable to be devised for light weight and small-sized OTM(On-The-Move) satellite communication system suitable to be mounted on vehicles. In spite of advantages of the double-input single-output architecture of a LNA such as reduction of the number of physical channels, it results in time-varying phase error between a fundamental mode path and a high-order mode path. This paper shows that the error can be corrected by adding pilot signals to the LNA and using signal processing, and also gives the measurement data to use the method mentioned above.

대전 도심지의 K 대역 위성통신 채널특성 분석

This paper describes the analysis results of channel characteristics in the operating area of satellite OTM (On-The-Move) terminal. The communication channel between the Koreasat-5 and OTM terminal on a test car was measured and recorded in downtown of Daejeon, using the received beacon signal of around 20 GHz. And the measurement data were statistically analyzed and then compared with highway and national road environments. The statistical evaluation of satellite channel was conducted by using probability density function and Markov model and then presented average connection duration(ACD), average fade duration(AFD), and level crossing rate(LCR) of downtown environment.

차기 군 위성통신체계 환경에서 이동형 위성단말의 채널 blockage 극복을 위한 확산기반 협업통신 기법의 성능 분석

본 논문에서는 차기 군 위성통신체계 환경에서 OTM(On-The-Move) 위성단말의 채널 blockage 신호 손실 보상을 위한 협업통신 기법을 제안하였다. 제안하는 협업기법은 인접 OTM 위성단말과 지상 무전기 체계를 통해 데이터를 공유하고 직교확산코드를 이용하여 대역확산 후 동시에 전송한다. 중첩되어 전송된 확산열은 EGC(Equal Gain Combining) 방식으로 결합한다. 성능 분석을 위해 OTM 위성단말의 blockage 채널을 2-state Markov chain으로 모델링하였으며, 이를 기반으로 협업단말들의 blockage 채널 상태에 따른 비트오류율을 도출하였다. 성능분석 결과 채널 조건이 더 나은 인접 OTM 위성단말의 협업으로 비트오류율 성능이 향상됨을 확인할 수 있었다. 특히 blockage 확률이 높을수록 협업을 통해 더욱 우수한 성능을 확인할 수 있었다. 그러나 서로 다른 지연을 갖는 확산 열 간 중첩으로 인해 협업단말 수 증가 시 다중접속간섭으로 인한 성능상의 제약이 있음을 확인하였다. To compensate signal loss due to the channel blockage in satellite communication link, we propose a cooperative communication scheme for OTM(On-The-Move) terminal in next generation satellite communication systems. The proposed scheme configures cooperation subnet with adjacent OTM terminal with the help of ground communication equipment. Shared data is spread by orthogonal spreading code, then the spread sequences are transmitted simultaneously. The receiver combines the power of received signals by EGC(Equal gain combining). The OTM terminal blockage channel is modeled by 2-state Markov chain. We evaluate the bit error rate according to the blockage channel of the channel state for the performance analysis of the proposed scheme. As a result, the proposed scheme shows better BER performance than traditional scheme with the help of subset members. In particular, the proposed scheme shows superior performance as the channel block probability is higher. However, as the number of subset members is increasing, there is a constraint because of the higher multiple access interference.

위성통신 시스템에서 이동형 위성단말을 위한 개루프 전력제어 알고리즘

ABSTRACT In this paper, we propose an open loop power control algorithm to control transmission power of the On-The-Move(OTM) Satcom terminal in GEO satellite communication environment. The proposed algorithm identifies the current channel state restricted by an obstacle or an antenna depointing loss based on the received beacon signal strength. On the basis of the determined signal attenuation causes, the OTM Satcom terminal turns off the RF output when an antenna tracking is failed. If the OTM Satcom terminal experiences a channel blockage by an obstacle, the terminal spreads the transmit data to increase data reception probability. To evaluate the performance of the proposed algorithm, we compare an adjacent satellite interference level and an outage probability. The results show the performance of the proposed algorithm is better than that of the conventional algorithm. 키워드 : 위성통신, 이동형 위성단말, 전력제어, 위성통신채널, 대역확산 Key word : Satellite communications, OTM terminal, Power control, Satellite communication channel, Spread spectrumJournal of the Korea Institute of Information andCommunication Engineering

이동형 위성단말을 위한 20 GHz 대역 채널 특성 분석

Abstract This paper describes the analysis results of channel characteristics in the operating area of satellite OTM(On-The-Move) terminal. The communication channel between the Koreasat-5 and OTM terminal on a test car is measured and recorded from Daejeon to Daecheon, using the downlink frequency of around 20 GHz. And the measurement data are divided into two classes ; highway environment and national road environment, and then are statistically analyzed. The statistical evaluation of satellite channel is conducted by using probability density function and Markov model and then presents average connection duration(ACD), average fade dura-tion(AFD), and level crossing rate(LCR) of highway environment and national road environment. Finally the statistics data of the two environments are compared with each other.Key words: Satellite Communication Channel, On-The-Move, Average Connection Duration, Average Fade Duration, Level Cross- ing Rate @[#\]D^(Agency for Defense Development)*_`+\Z/ab\#(Department of Electronic Engineering, Chungbuk National University)Manuscript received October 8, 2013 ; Revised November 25, 2013 ; Accepted December 1, 2013. (ID No. 20131008-090)Corresponding Author: Kun-Sup Kwon (e-mail: kevin.kwon@add.re.kr)

Chatter-free sliding mode control for inertial stabilization of OTM (On-the-move) antenna driven by gear and flexible shaft

In this work, an on-the-move (OTM) antenna which is mounted on ground vehicles and is used for communication between vehicle and satellite was studied. Since vehicles move during communication, active antenna line-of-sight (LOS) stabilization is a core technology to guarantee satellite communication quality. Stabilization control of the antenna LOS which is driven by a motor coupled with gears and flexible driving shafts was investigated. In consideration of the finite stiffness of the shaft and disturbance torque due to vehicle motion coupled with gear ratio, a stabilization control is proposed. The proposed control is based on an integral sliding mode method (SMC). Since this SMC is robust and chatter free, it gives fine stabilization performance and is easy to implement without consideration of wear and tear on actuators. The feasibility of the proposed control design was verified along with some simulation results.

기어와 유연축을 갖는 구동계로 구동되는 OTM 안테나 시선의 안정화 제어

In this study, an OTM(on-the-move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite while moving was addressed. Since LOS(line-of-sight) of antenna should direct satellite consistently while vehicle moving to guarantee high satellite communication quality, active antenna LOS stabilization is a core technology for OTM antenna. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. In consideration of driving mechanism which consists of gear train and flexible driving shafts, a two-mass-system dynamic model coupled with vehicle motion was presented. An internal PI-control loop + outer PI-control loop structure has been suggested in order to damp the torsional vibration and stabilize control system. The classical pole-placement method was applied to design control gains. In addition, a vehicle motion compensation control beside of the feedback control loop has been suggested to improve LOS stabilization performances. The feasibility of the proposed control design was verified along with some experimental results.

Stabilization Control of line of sight of OTM(On-The-Move) Antenna

The 4-th generation of mobile communication aims to realize global, fast and mobile communication service. The satellite communication charges a key role in this field. In this study, an OTM(On-The-Move) antenna which is mounted on ground vehicles and is used for mobile communication between vehicle and satellite was addressed. Since vehicles move during communication, active antenna line-of-sight stabilization is a core technology to guarantee high satellite communication quality. Stabilization of a satellite tracking antenna which consists of 2-DOF gimbals, an elevation gimbal over an azimuth gimbal, was considered in this study. Various disturbance torques such as static and dynamic mass imbalance torques, variation of moment of inertia according to elevation angle, friction torque related to vehicle motion, equivalent disturbance torque due to antenna roll motion, etc. were analyzed. As a robust stabilization control, rate feedback with sliding mode control and position feedback with proportional+integral control was suggested. To compensate antenna roll motion, a supplementary roll rate feed forward control was included beside of the feedback control loop. The feasibility of the analysis and the proposed control design were verified along with some simulation results.

Unpatterned Ferroelectric Thin Film Measurements for Optimization of Perovskite Oxide Thin Film Based Microwave Devices

The Army's Future Force (FF) antennas require increased bandwidth for multimission communications; increased antenna gain for robust communications and range extension; increased mobility for high data rate on-the-move (OTM) communications; and undetectable antenna visual signatures for low probably of mission detection and increased survivability. Electronic scanning antennas (ESA's) are the key components for such advanced communication systems. ESA's provide rapid scanning capability, which enables modes such as multiple target tracking, track while scan, and sensor fusion operation. One of the major challenges, which must be overcome before such advanced ESA systems can be realized, is the development of affordable, low loss, high tunability, low power, lightweight, and high performance microwave frequency phase shifters. The enabling technology for such phase shifters is centered on the development of single-phase nanometer-scale constituent perovskite oxide thin films with enhanced dielectric, insulating, and microstructural properties. The Army Research Laboratory (ARL) has successfully designed, fabricated, characterized, and optimized, novel pure and acceptor doped Ba 0.6 Sr 0.4 TiO 3 (BST) based thin films on MgO substrates with excellent microwave material properties. Pure and 1-mol% Mg doped BST thin films were fabricated by the metalorganic solution deposition (MOSD) technique and the film's dielectric properties were characterized at microwave frequency via a tuned coupled-split dielectric resonator technique developed at NIST. Using this measurement technique, for first time ever, has allowed the true “singular” dielectric loss (tan δ) and permittivity (ϵ r ) of the BST-based films to be assessed and optimized without the influence of device design (radiative losses) and electrode metallization (conductor losses).