Communication Distance Research Articles

PDDQN-HHVBF Routing Protocol Based on Empirical Priority DDQN to Improve HHVBF

Reinforcement learning (RL) has been successfully applied to underwater routing protocols due to its powerful ability of distributed decision making. However, the traditional RL has slow convergence speed and low learning efficiency in underwater. Meanwhile, too many studies focus on using RL to find low hop paths rather than short distance paths in underwater routing, while the long distance of ocean communication is the significant reason for the packets collision and energy loss in underwater. Based on the above problems, this paper proposes the PDDQN-HHVBF (Empirical Priority DDQN to Improve Hop-by-Hop Vector-Based Forwarding) protocol for M-UWSNs (Mobile source node Underwater Wireless Sensor Networks), in which AUV (Autonomous Underwater Vehicle) is used as source node to collect data and transmit data hop-by-hop to Sink node through underwater nodes. The proposed protocol is adopt to find the optimal relay nodes in pipeline referred HHVBF protocol by requesting the max Q value according to three states of the residual energy of nodes, the number of candidate relay nodes and the geographical location information of all candidate relay nodes in time. This because PDDQN-HHVBF avoids the strong correlation between data samples, and its playback samples will not be too concentrated or lead to over fitting. It can converge rapidly in underwater environment. In addition, the requesting Q value mechanism related to the geographical location information can find the optimal relay node with short distance propagation in large-scale networks, which will reduce the number of packets collision, and then saving energy and improving network lifetime. In addtion, the in-time requesting for Q value can cope with the nodes drift affected by ocean current movement. In addition, the Q value related to the residual energy of nodes and the number of candidate relay nodes will effectively load balancing nodes, prolong network lifetime and avoid routing holes. Finally, the “Store-Carry-Forward” mechanism proposed for AUV, this mechanism store and carry packets when facing routing holes until find the optimal relay node for forwarding, which will improve PDR and save energy of AUV significantly. The simulation results show that, the proposed PDDQN-HHVBF protocol converges about 30% faster than DQELR. Although its delay is higher than DQELR and ROEVA for requesting Q value. It outperforms VBF, HHVBF, DQELR, and ROEVA in terms of energy efficency, PDR, and lifetime, which are analyzed by varying speed of nodes from 0 m/s to 3 m/s with 1000 nodes and varying number of nodes from 500 to 3000 with speed in 1 m/s.

Asymmetric 160/80 Gb/s TWDM PON with supported transmission method utilizing FBG and DML

Abstract The primary objective of time wavelength-division multiplexing passive optical networks (TWDM-PONs) development at the moment is the cost-effective capacity acquisition. This work addresses this issue by demonstrating a full-system TWDM-PON was selected as a primary choice to NG-PON2 by Full-service access network (FASN) unanimously agreed and International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) G.989. An asymmetric TWDM NG-PON2 was demonstrated that provides 160 Gbps downstream and 80 Gbps upstream which is the target capacity by ITU-T G.989.1 based on OptiSystem-7 software. We propose to use fiber Bragg grating (FBG) and Er-doped fiber amplifier (EDFA) to reduced both of the chromatic dispersion effect and system attenuation until given permission to enhance the distance communication system. The proposed system’s performance is evaluated and compared with other works and ITU-T G.989.2 recommendations to demonstrate how the system can be enhanced in terms of capacity, link distance, bit error rate (BER), Q-factor and receiver sensitivity. According to the results, the optimum possible distance under communication requirements (6 for the Q-factor and 10−9 for the BER) is around 65 km for the system with dispersion compensation. With the help of the low-cost directly modulated laser (DML) for uplink, we successfully improve the power budget to 41.2 dB along 65 km of bidirectional fiber at a 1:512 splitting ratio.

5G ДВУХДИАПАЗОННАЯ ПРЯМОУГОЛЬНАЯ МИКРОПОЛОСКОВАЯ АНТЕННА С ДВУМЯ ТРАВЛЕНИЯМИ И ВЕРХНИМ ШЕСТИГРАННЫМ ВЫРЕЗОМ НА КОНЦЕ CPW FED

Around the world, wireless or distant communication has become fundamental and indispensable.Every day, billions of users access calls, the internet, and social media. Many electricalequipment, including the antenna, are used in the sophisticated networks and systems that supportthat massive information interchange. An electrical device known as an antenna sends or receivesinformation across space. The antenna is a key component in many systems, including radio andtelevision transmission, communications receivers, radar, cellular phones, Bluetooth-enabledgadgets, and satellite communications. The rapid expansion of wireless technology and personalcommunication has increased the demand for multiband antennas, which can operate at severalfrequencies and are suited for a variety of applications. Dual-band coplanar waveguide (CPW)fed rectangular microstrip patch antenna for 5G, WiMAX band, ISM Band, and WLAN applicationsis presented in this paper. The proposed antenna is robust, cheap, light weight, and easy tofabricate, resonating at 2.4 GHz in -12.182379 s11 with 205.7 MHz BW and 3.42 GHzin -37.344879 s11 with 464.9 MHz BW whereas gain is 3.85 and 3.41 respectively. Patch elementsare placed on isolation FR408 (loss-free) substrate of relative permittivity 3.75 kept at a substrateheight of 1.6 mm. Results of simulation are presented using CST STUDIO SUITE 2019.

Creation and test of applied software of network of wireless sensors for agriculture

The article describes applied software of units of such complex hardware-software system, as plants` state monitoring system for application in agriculture and ecological monitoring. The mentioned system consists of data acquisition system in the form of wireless sensor network and adaptive part in the form of decision-making support system. The authors described main applied software of au- tonomous nodes of wireless sensor network and implementation of some program functions of decision-making support system. Wire- less sensor network includes many autonomous wireless sensors, so the main criteria during applied software creation was assuring the energy efficiency of operation of autonomous measuring nodes and network coordinator, and correct interaction of nodes within all network. As it is very difficult to perform testing of applied software of wireless nodes individually in field conditions, it was tested the network cluster, including hardware and software as a whole, in conditions like to applied task. The main parameters, which define the correctness of applied software operation, were estimated. These parameters include, for example, time of network selforganization, distance and quality of stable communication, time of autonomous operation of wireless nodes without charging batteries and so on. To create applied software for the decision-making support system, first of all, methods of plants` state diagnosing and estimating the factors, which influence the plant state, were developed. For this, the field experiments were conducted to determine sufficient dose of herbicide application and estimate the soil moisture using the chlorophyll fluorescence induction method. For processing measured data, several methods of machine learning were used, including neural network approach. Application of machine learning methods made it possible, on the base of acquired data, to make early diagnostics of influence of stress factors on the plant even before the appearance of visual manifestations of such negative influence and determine the decrease of soil moisture through the diagnostics of plant itself, and inform the user about this.

Ambient Backscatter-Based Power Control Strategies for Spectrum Sharing Networks

Prior works on power control strategy need to estimate all users’ channel state information (CSI), which consumes both spectrum and time. Two efficient and low-complexity power control strategies, namely quality of experience (QoE) based power control scheme and distance based power control strategy, are proposed for an ambient backscatter based spectrum-sharing network. In the proposed power control schemes, there is no need to estimate all users’ CSI. In the QoE-based power control strategy, only the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K}$ </tex-math></inline-formula> primary users with the highest priority feedback their CSI. We introduce an attenuation factor to reduce the transmit power to satisfy the interference threshold on primary users. Then, considering the short transmission distance of secondary backscatter communication and randomly distributed primary users, we propose the distance-based power control scheme, in which only the users within the backscatter distance need to feedback their CSI. Closed-form expressions for the outage probabilities of primary and secondary systems are derived over the Nakagami- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${m}$ </tex-math></inline-formula> channels under the proposed two power control strategies. The system energy efficiency are also analyzed. Simulation results are conducted to verify the analytical results. Finally, outage performance and energy efficiency of the proposed schemes are compared with that of the existing nearest- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K}$ </tex-math></inline-formula> users based power control strategy. It is shown that the proposed power control strategies have lower outage probabilities and higher energy efficiency.

An Energy-Efficient and High-Data-Rate IR-UWB Transmitter for Intracortical Neural Sensing Interfaces.

This paper presents an implantable impulse-radio ultra-wideband (IR-UWB) wireless telemetry system for intracortical neural sensing interfaces. A 3-dimensional (3-D) hybrid impulse modulation that comprises phase shift keying (PSK), pulse position modulation (PPM) and pulse amplitude modulation (PAM) is proposed to increase modulation order without significantly increasing the demodulation requirement, thus leading to a high data rate of 1.66 Gbps and an increased air-transmission range. Operating in 6 - 9 GHz UWB band, the presented transmitter (TX) supports the proposed hybrid modulation with a high energy efficiency of 5.8 pJ/bit and modulation quality (EVM< -21 dB). A low-noise injection-locked ring oscillator supports 8-PSK with a phase error of 2.6°. A calibration free delay generator realizes a 4-PPM with only 115 μW and avoids potential cross-modulation between PPM and PSK. A switch-cap power amplifier with an asynchronous pulse-shaping performs 4-PAM with high energy efficiency and linearity. The TX is implemented in 28 nm CMOS technology, occupying 0.155mm2 core area. The wireless module including a printed monopole antenna has a module area of only 1.05 cm2. The transmitter consumes in total 9.7 mW when transmitting -41.3 dBm/MHz output power. The wireless telemetry module has been validated ex-vivo with a 15-mm multi-layer porcine tissue, and achieves a communication (air) distance up to 15 cm, leading to at least 16× improvement in distance-moralized energy efficiency of 45 pJ/bit/meter compared to state-of-the-art.

On Robust Millimeter Wave Line-of-Sight MIMO Communications With Few-Bit ADCs

This work focuses on providing robust line-of-sight (LoS) spatial multiplexing at flexible communications distances and directions. Considering oblique LoS uniform linear arrays, we first derive the rank-deficient and orthogonal conditions for the LoS MIMO channel matrices. With this discovery, the topology of high spatial-resolution on one side of the link is shown with a wide full-rank-channel guarantee interval over distance and direction variations. Additionally, to reduce the implementation costs and power consumption, we propose to use low amplitude-resolution quantizers at the side of high spatial-resolution. With numerical evaluations on systems having few-bit analog-to-digital converters (ADCs), the proposed system design is shown to simultaneously achieve a higher spectrum efficiency and higher energy efficiency compared to a conventional single-stream high-amplitude-resolution over a wide signal-to-noise-ratio (SNR) range. Furthermore, we investigate channel equalization under the extreme case of using 1-bit ADCs. After providing a new viewpoint on the generalized approximate message passing (GAMP) algorithm from constrained Bethe free energy minimization, our simulations on bit-error-rates show that the GAMP algorithm can significantly reduce the performance degradation due to coarse quantization and can significantly outperform the Bussgang decomposition based linear minimum-mean-square-error estimator, especially at high SNRs.

Highly Integrated Multifunctional Antenna for Global Navigation Satellite System

This communication proposes a new highly integrated multifunctional global navigation satellite system (GNSS) antenna used for navigation or surveying high-precision area, the fourth-generation (4G) mobile communication, and short-distance wireless communication. The antenna consists of four elements, saying: 1) a low-profile navigation element on one substrate covering all the GNSS bands and 2) two long-term evolution multiple-input–multiple-output (LTE-MIMO) elements and one Wi-Fi element uniformly distributed on the edge of the substrate. This symmetrical configuration ensures the navigation element’s low axial ratio (AR) and radiation pattern symmetry, as well as navigation accuracy. In addition, to enhance the isolation between the GNSS element and other three elements under high integration, these three elements are designed to avoid resonating within the GNSS bands. The measured peak gains of the GNSS element are 6.0 dBi from 1.16 to 1.28 GHz and 6.5 dBi from 1.52 to 1.62 GHz. The −6 dB impedance bandwidth of the LTE-MIMO elements can cover 840–960, 1800–2200, and 2500–2700 MHz. The distance communication of the Wi-Fi element is 80 m. The experimental results indicate that the proposed multifunctional antenna features low profile, high integration, and wideband, implying potential application in the multifunctional satellite navigation system.

Outage probability minimization for vehicular networks via joint clustering, UAV trajectory optimization and power allocation

In this paper, we consider the vehicular uplink communication scenario where vehicles in the same lane travel in a direction within the coverage of the base station. Due to the long communication distance and poor signal quality at the cell edge, an unmanned aerial vehicle (UAV) is used as a mobile relay to improve the communication quality. Our goal is to minimize the communication outage probability by jointing vehicle clustering with UAV trajectory optimization and power allocation of each node. Since the cluster head position, UAV position and power of each node are coupled, the primary complex problem is divided into three sub-problems namely vehicle clustering, trajectory optimization and power allocation. Firstly, the improved K-means clustering algorithm is used for vehicle clustering by addressing the minimum–maximum distance criterion. In order to adapt to the changing network topology, the cluster head vehicle is determined dynamically. Then the joint Lagrangian gradient ascent method is used to determine the UAV position and the power of each vehicle through alternate iterations. The simulation results show that the proposed joint optimization scheme (J-CTOPA) is better than the equal power scheme with fixed relay position (FR-EP) and the power allocation scheme with cruise relay trajectories (CT-PA). The results also show that faster convergence and stronger stability can be achieved while the outage probability is reduced.

Developing hybrid car-to-car communication system based on MIMO visible light and radio frequency

This paper combines the advantages of both VLC communication and RF communication for car-to-car applications to achieve a higher data rate, more range coverage, smaller delay, and smaller BER. In the proposed scheme, the VLC maximum communication distance is chosen as 100 m per-hop approximately, which can be extended through multi-hop up to the timeout window of 5 hops. In contrast, the RF maximum communication distance is chosen as 200 m per-hop approximately, which is reasonable at the frequency band of 70 GHz to 90 GHz due to the high attenuation at this frequency band. A MATLAB simulation for a car-to-car framework is built to demonstrate and compare the BER, throughput, and delay outcomes at a hybrid VLC and RF communication. Our results show that VLC can achieve up to four times of the RF throughput while maintaining low BER of 10−6 and small delay of 10−4 with respect to RF communication only.

Transport and geographic location of recreational and tourist centers as a factor in the development of tourism (on the example of Chernivtsi oblast)

The peculiarities of the transport and geographical position of Chernivtsi oblast and the possibilities of its use for the development of tourism and recreation are analyzed. The possibilities of transport connection of the region with other regions of Ukraine and foreign countries are investigated. Some aspects of the location of individual recreational and tourist centers of the region relative to the most important transport highways in the context of the transfer of tourists to the main destinations are revealed. Transport services are an integral part of the tourist product and an important factor in the development of tourism in the region. The transport accessibility of the most popular tourist facilities depends on the level of development of the transport complex, which in turn affects the price of the tourist product, its quality and the final impressions of tourists from visiting tourist places. One of the key factors affecting the development of the transport complex of the region is its transport and geographical position. The influence of this factor is first of all revealed in the location of the region relative to the main international and important national routes of communication, as well as in the distance and ease of communication from the main transport highways to the centers of recreational and tourist activity. Chernivtsi oblast, despite the size of the territory (the smallest by this indicator in Ukraine), has a favorable transport and geographical position in the context of tourism development. This is due to the following aspects: 1) A number of highways of international and national importance pass through the territory of the region, which continue in the neighboring countries – Romania and Moldova and other regions of Ukraine. The total length of public roads in the region in 2020 was 2.9 thousand km. Thus, there are more than 358 kilometers of highways per 1,000 km2 of the region’s area. 2) A fairly developed network of railway tracks has been formed in the region, within which a number of suburban and intercity railways operate. In 2020, the length of railway tracks in the region was 413 kilometers, or almost 51 km of tracks per thousand square kilometers of the region’s territory. 3) An international airport operates in Chernivtsi oblast center. This is the only facility in the region that allows air communication with other regions of Ukraine and countries of the world. Therefore, Chernivtsi oblast occupies a favorable transport and geographical position. This is primarily due to its border location and the availability of transport connections with Romania and Moldova, as well as a significant number of road and rail connections, an international airport in Chernivtsi. In general, the transport and geographical location of the main tourist and recreation centers is favorable for the development of tourism. However, the state of transport infrastructure, in particular most local roads, creates significant obstacles in the provision of quality tourist services. The most problematic aspect in this matter is the restoration of the bridge across the Prut River between the villages of Dubivtsi and Hlynnytsia. This will make it possible to significantly improve the road connection of recreational and tourist centers located in the southwestern part of the region with the M-19 and H-10 highways, which play the most important role for the arrival of tourists in the region. It is also important to increase the number of direct flights between the regions of Ukraine and with foreign countries, rail transport from Chernivtsi and to restore regular air flights.

FIRST YEAR STUDENT ATTITUDES TOWARD DISTANCE LEARNING

Over the last two years, since the beginning of the COVID-19 pandemic, Higher Education Institutions (HEIs) in Serbia worked in the modality of distance learning – instructions and students` assignments were performed by distance, while colloquia and exams were realized in traditional conditions. Regardless of modality, HEIs have to ensure high-quality education in every single course. In this sense, the feedback from students is very important. The purpose of this study is to investigate students` attitudes about four dimensions of distance learning – fulfilment of preconditions, organization and realization of instructions, advantages/disadvantages of distance learning, communication and social interactions. Data was collected from 183 first-year students within three courses at The Academy of Applied Technical Studies Belgrade, and was processed in the SPSS software package. The research strategy included descriptive statistics, while the Likert scale was used to assess the satisfaction of the respondents. Analysis of variance and independent-sample t test were used to examine differences in opinions among different groups of respondents. The results of this study could be important for instructors, HEIs that operate in similar conditions, policymakers in the field of HE in Serbia, as well as for present and future research in this area.

Graph attention mechanism based reinforcement learning for multi-agent flocking control in communication-restricted environment

To solve the poor performance of reinforcement learning (RL) in the multi-agent flocking cooperative control under the communication-restricted environments, we propose a multi-agent cooperative RL (MACRL) method based on the equivalent characteristics of the agents in the flocking task. A distance graph attention (GAT) mechanism is introduced into the policy network of the proposed MACRL to change the agent’s attention weights related to neighbors and reduce the influence of remote neighbors which have poor communication quality on the agent’s behavioral decision-making. Furthermore, a distance GAT-based MACRL (DGAT-MACRL) algorithm is proposed for multi-agent flocking control in the communication-restricted environment. The simulation results show that the proposed flocking algorithm has good adaptability to the communication delay and the communication distance constraint environments. The flocking control effect is significantly better than other RL-based flocking algorithms and traditional flocking algorithms. In addition, the good experimental performance has also confirmed that the proposed DGAT-MACRL is an effective solution to the problem of how to improve the adaptability of traditional RL to the flocking control system with a dynamic scale. Our algorithm provides a novel and practical algorithm offering an effective method for the cooperative task accomplished by multi-agent in non-ideal environments.

Blind channel estimation for DCO-OFDM based vehicular visible light communication

Blind channel estimation (CE) methods for OFDM based RF communication provide high-rate transmission by eliminating pilot overhead in conventional pilot-based methods, at the cost of lower accuracy. However, there is no work on the blind CE for OFDM based visible light communication (VLC) systems. In this paper, we propose a novel blind CE method for vehicular VLC with the goal of improving CE accuracy based on the exploitation of the channel statistics derived, by utilizing extensive amount of data collected for different communication angles, distances, and ambient light conditions. First, the normalized channel frequency response (CFR) of the V2LC channel is demonstrated to be invariant of inter-vehicular distance, relative transmitter/receiver zenith angle and ambient light. Then, this channel characteristic is exploited in the blind CE to improve its accuracy with two-step estimation of normalization factor. Extensive simulations at different vehicle speeds show that the proposed method outperforms the pilot-based and superimposed training-based CE methods in terms of spectral efficiency both for all modulation schemes and at all relative speeds. The proposed blind channel estimation (CE) method provides 9.77% increase in the spectral efficiency, compared to the second best method, superimposed training-based CE, at 20 dB signal-to-noise ratio (SNR) and 160 km/h relative speed, for 64-Quadrature Amplitude Modulation (QAM) Direct Current-Biased Optical Orthogonal Frequency Division Multiplexing (DCO-OFDM). Moreover, the real-time performance of the proposed blind CE is demonstrated for a realistic vehicle mobility scenario extracted from SUMO.

Propulsion Energy Minimization for Fixed-Wing-UAV-Assisted Full-Duplex Mobile Relaying via Hybrid Trajectory Design

This paper solved a propulsion energy minimization problem subject to a total data-bit constraint of an unmanned aerial vehicle (UAV)-enabled full-duplex mobile relaying system, where a fixed-wing UAV is dispatched as a full-duplex mobile relay to assist data transfer from a source to a destination. Here, three trajectory flying modes are used, namely, the UAV first flies along a circular path above the source, next flies to the destination along a straight line, and finally flies along a circular path above the destination until all the data-bits have been transferred. Since the propulsion energy minimization problem is a nonconvex mixed integer programming problem, its closed-form solution is not tractable, and hence, it is transformed to three subproblems so as to simplify its solution. After solving the three subproblems, an iterative algorithm is proposed to achieve a suboptimal solution to the propulsion energy minimization problem, leading to a new hybrid circular/straight trajectory (HCST) design. Computer simulations are conducted to validate the effectiveness of the proposed HCST design. It is shown that the proposed HCST design performs well in terms of energy saving for the long distance and big data communication cases compared with the straight or circular flight trajectory design.

PATH-03. IMPACT OF GAP-43 AND ACTIN EXPRESSION ON THE OUTCOME AND OVERALL SURVIVAL IN DIFFUSE AND ANAPLASTIC GLIOMAS

Abstract Background. Distant intercellular communication in gliomas is based on the expansion of tumor microtubuli (TMs), where actin forms cytoskeleton and GAP-43 mediates the axonal conus growth. We aimed to investigate the impact of GAP-43 and actin expression on overall survival (OS) as well as crucial epidemiologic, radiological and neuropathological prognostic factors. Methods. FFPE tissue of adult patients with diffuse and anaplastic gliomas, who underwent first surgery in our center between 2010 and 2019, were selected. GAP-43 and actin expression was analyzed using immunohistochemistry and semi-quantitatively ranked. Clinical, neuropathological as well as follow-up-data were gained from the institutional neuro-oncological database. Results. 118 patients with a median age of 46 years (IqR: 35 – 57) were evaluated. 48 (41%) presented with a diffuse glioma and 70 (59%) revealed anaplasia. 96 (82%) cases presented with intermediate or strong GAP-43 expression and 78 (67%) with no or light actin expression. Tumors with higher expression of GAP-43 (p=0.024, HR=1.71/rank) and actin (p&amp;lt; 0.001, HR=2.28/rank) showed significantly reduced OS. IDH1 wildtype glioma demonstrated significantly more expression of both proteins: GAP-43 (p=0.009) and actin (p&amp;lt; 0.001). The same was confirmed for anaplasia (GAP-43 p=0.028, actin p=0.029), higher proliferation rate (GAP-43 p=0.016, actin p=0.038), contrast-enhancement in MRI (GAP-43 p=0.023, actin p=0.037) and age (GAP-43 p=0.004, actin p&amp;lt;0.001). Conclusions. The intercellular distant communication network in diffuse and anaplastic gliomas formed by actin and GAP-43 is associated with a negative impact on overall survival and with oncologically unfavorable prognostic features.

Dialect diversity and total factor productivity: Evidence from Chinese listed companies.

Using a sample of Chinese listed companies over the 2007-2019 period, we examined the influence of dialect diversity on a firm's total factor productivity. We found that dialect diversity affects the psychological distance of interpersonal communication and significantly affects the firm's total factor productivity. The results are robust to a battery of tests based on different specifications. The relationship between dialect diversity and a firm's total factor productivity is more pronounced in state-owned enterprises, firms located in southern regions, and more capital-intensive firms. Furthermore, we demonstrated an innovative factor flow mechanism and a human capital accumulation mechanism through which dialect diversity inhibits total factor productivity. Overall, this paper provides new evidence and decision-making reference for coordinating the protection of dialect diversity and high-quality economic development.

A Three-Phase CDRT Strategy Based on Successive Relay for Smart Grid

In the vision of the future smart grid, the communication is often featured by wide range, massive connect, and low latency, which poses new requirements on the reachable distance and spectral efficiency of wireless communication. In this regard, this paper studies ergodic capacity enhancement by applying successive relay (SR) technology to a non-orthogonal multiple access (NOMA) based Coordinated Direct and Relay transmission (CDRT) system, where a base station (BS) communicates with a near user (NU) directly while communicating with a far user (FU) with the help of a group of relays. We design a novel three-phase CDRT strategy based on SR technology to overcome the half-duplex (HD) constrain without introducing additional noise. The proposed strategy can improve the spectral efficiency while expanding the communication coverage, which to some extent improves the communication quality of the edge users of the smart grid and reduces the communication delay. To analyze the performance of the proposed three-phase CDRT strategy, an exact and closed-form expression for ergodic capacity of the NU, the FU, and the whole system is derived. Finally, the numerical and simulation results validate the analysis results and show that the proposed strategy can improve the ergodic capacity of FU without reducing the capacity scaling of NU.

Enhancing Coordination Around Cancer Biomarker and Hereditary Genetic Testing Among Members of the Multidisciplinary Care Team

Abstract Introduction/Objective Advances in precision medicine necessitate a closer integration across pathologists, genetic counselors, and other members of the multidisciplinary cancer care team (MDT). Recognizing that physical distancing and fragmented communication may hinder care delivery, the Association of Community Cancer Centers (ACCC) ran a multi-year initiative to explore ways to improve MDT care coordination. Methods/Case Report ACCC held a multistakeholder leadership summit to identify and discuss critical issues regarding biomarker and hereditary genetic testing and the ways in which pathology and genetic counseling professionals interface with the cancer MDT. Through a consensus-driven process, participants identified key opportunities for achieving optimal integration. ACCC also conducted a national survey to explore barriers around biomarker and hereditary genetic testing. Building off these insights, ACCC conducted virtual workshops at three community cancer programs to improve processes around biomarker testing and targeted treatment planning. Results (if a Case Study enter NA) The pathology leadership summit identified the following priorities: 1) streamline and standardize the biomarker test ordering process; 2) improve tissue handling to optimize timely biomarker testing; 3) strengthen communication between pathologists and genetic counselors; 4) empower pathologists with leadership opportunities. In the ACCC survey (n=659), 57% indicated that some or most of their pathologists were generalists. 21% only held one general tumor board. 6% indicated that pathologists often do not attend tumor boards or cancer committee meetings. 64% indicated that pathologists can directly access some or all medical oncology patient records. 67% sent some or most biopsy samples out for biomarker testing. In the ACCC workshops, cancer programs in KS, NC, and NV identified ways to improve the timeliness of genetic counseling referrals and coordinate biomarker testing. Following the workshops, 64% indicated they planned to make moderate or significant changes in their processes. Conclusion Improving collaboration across pathologists, genetic counselors, and the rest of the cancer MDT may lead to more timely and comprehensive biomarker and hereditary genetic testing. These findings may help cancer programs refine processes of care.

Expansion of fibroblast cell sheets using a modified MEEK micrografting technique for wound healing applications

Cell sheet engineering, a scaffold-free approach to fabricate functional tissue constructs from several cell monolayers, has shown promise in tissue regeneration and wound healing. Unfortunately, these cell sheets are often too small to provide sufficient wound area coverage. In this study, we describe a process to enlarge cell sheets using MEEK micrografting, a technique extensively used to expand skin autografts for large burn treatments. Human dermal fibroblast cell sheets were placed on MEEK’s prefolded gauze without any use of adhesive, cut along the premarked lines and stretched out at various expansion ratios (1:3, 1:6 and 1:9), resulting in regular distribution of many square islands of fibroblasts at a much larger surface area. The cellular processes essential for wound healing, including reattachment, proliferation, and migration, of the fibroblasts on expanded MEEK gauze were superior to those on nylon dressing which served as a control. The optimal expansion ratio with the highest migration rate was 1:6, possibly due to the activation of chemical signals caused by mechanical stretching and an effective intercellular communication distance. Therefore, the combination of cell sheet engineering with the MEEK micrografting technique could provide high quality cells with a large coverage area, which would be particularly beneficial in wound care applications.