Capacity Scaling Research Articles

Efficient Dense Orbital Angular Momentum Demultiplexing Enabled by Quasi‐Wavelet Conformal Mapping

AbstractOrbital angular momentum (OAM) has recently attracted increasing interest in optical communications for capacity scaling by OAM mode‐division multiplexing (MDM). OAM (de)multiplexer is crucial to the success of OAM‐MDM communications. Scalable and efficient dense OAM demultiplexing is highly desired, but full of challenges. Here, a quasi‐wavelet conformal mapping method is proposed and demonstrated to implement scalable and efficient dense OAM demultiplexing. The OAM mode is divided at the input plane into multiple concentric rings, which are mapped to multiple tilted plane waves and arranged side by side in a line. The engineered transformed light beams with periodic extension and increased length enable narrow focused spot width, reduced beam overlap, and suppressed demultiplexing crosstalk. The quasi‐wavelet conformal mapping method is compared with conventional log‐polar transformation scheme and hybrid log‐polar and fan‐out technique, and the crosstalk matrix for OAM demultiplexing is measured. Efficient OAM demultiplexing is demonstrated for 15 OAM modes (OAM−7 to OAM+7) with a maximum crosstalk of −12.1 dB in the experiment. Moreover, the method is also applied to system‐level data‐carrying OAM‐MDM communications with favorable performance. The demonstrated quasi‐wavelet conformal mapping method may pave the way for future ultrahigh capacity dense OAM‐MDM communications with a large number of OAM modes.

Design And Construction Of Cabinet Dryer With Variation Of Blower Speed Using Charcoal Combustion On Chilli Plants

Indonesia is one of the tropical countries where there are many entrepreneurs engaged in chili farming found in rural areas. Chili is a commodity plant that is in great demand throughout the world and in Indonesia, therefore without good processing or preservation, the quality of chili quickly rots and the price drops in the market. In the chili processing process, it is very dependent on sunlight, but due to the uncertain climate and drying using sunlight, it needs a long and unhygienic process, causing the chili processing process to be hampered. For this reason, the design of a drying system that utilizes heat from burning charcoal is specifically designed to speed up the drying process. This chili drying system utilizes heat from burning charcoal in the furnace and flows hot air into the system with the help of a blower whose speed is varied, namely 6000 Rpm, 4000 Rpm and 2000 Rpm, with variations in the testing capacity scale to determine the tamping power on an efficient rack when this dryer works. After testing the tool, it is known that in a drying time of 30 minutes, the variation is more effective with an even distribution of heat in the system with a maximum blower speed of 100 grams with a drying rate of 20% to 30%.

Incorporating justice, equity, and access priorities into land trusts' conservation efforts

While the mainstream U.S. environmental movement has long promoted land conservation, a growing focus considers its intersections with social and political issues. In this study, we examine the ways in which land trusts (private nonprofit conservation organizations) engage with justice, equity, and access in their work, and how such issues interact with long-standing priorities of biodiversity and land conservation. Using survey data from the Land Trust Alliance's 2015 Census, we find the following to be associated with greater likelihood of reporting justice, equity, and access impact: protecting land in urban areas, drawing on a broad base of volunteers and visitors, and prioritizing local community work over broader landscape-scale conservation efforts. Supported by qualitative data collected through interviews with six land trusts, we found three primary areas of tradeoffs that land trusts consider when incorporating justice-focused work into conservation priorities: scale of impact, capacity, and public access. Ultimately, we propose a series of individual and systemic recommendations to more effectively navigate these tradeoffs and promote just and equitable practices.

First Use of Non-Invasive Spinal Cord Stimulation in Motor Rehabilitation of Children with Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is characterized by the degeneration of spinal alpha motorneurons. Nusinersen demonstrated good efficacy in the early disease phases. The feasibility of transcutaneous spinal cord stimulation (tSCS) in motor rehabilitation of patients with spinal cord injury has been demonstrated. We hypothesize that tSCS may activate intact and restored by nusinersen motorneurons and slow down the decline in motor activity, and may contribute to the development of motor skills in children with SMA. A case series is presented. Five children (6-13 years old) with SMA type II or III participated in the study. They were treated with nusinersen for ~2 years. Application of tSCS was carried out during physical therapy for 30-40 min per day in the course of 10-14 days. Outcome measures were goniometry of joints with contracture, forced vital capacity (FVC), RULM and HFMSE scales. The participants tolerated the stimulation well. The reduction of the contracture was ≥5 deg. RULM and HFMSE increased by ~1-2 points. Predicted FVC increased by 1-7% in three participants. Each participant expanded their range of active movements and/or learned new motor skills. Spinal cord stimulation may be an effective rehabilitation method in patients treated with nusinersen. More research is needed.

An Analog EIC-PIC Receiver With Carrier Phase Recovery for Self-Homodyne Coherent DCIs

Coherent techniques, used for high-capacity optical links, conventionally use high-speed ADCs and digital signal processing, which make them power hungry. For short-reach coherent links such as data center interconnects, power consumption, form factor, cost, and latency have to be greatly reduced. Co-designed photonic and electronic integrated circuits, in the optical and electrical analog domains, respectively, can achieve these goals. In this brief, for the first time, we present integration of a silicon photonic integrated coherent receiver (ICR) front-end with an electronic carrier phase recovery chip, as a part of a complete coherent receiver solution. A phase shifter in the ICR (fabricated in a 220 nm silicon-on-insulator technology) receives feedback from the CPR chip, and the combination compensates for the time varying phase offset between the modulated signal and the unmodulated carrier in the closed loop configuration. In this proof-of-concept demonstration, we present experimental results obtained from the stand-alone ICR, and its system level integration with CPR chip, for QPSK signals. The technique can be extended to a higher-order modulation formats, such as 16-QAM, for capacity scaling. The proposed scheme is suitable for carrier-forwarded coherent links, such as polarization multiplexed carrier based self-homodyne links.

Techno-Economic Evaluation of Future Thermionic Generators for Small-Scale Concentrated Solar Power Systems

Small-size concentrated solar power (CSP) plants are presently not diffused due to a too-high levelized cost of electricity (LCoE), contrarily to CSP plants with capacity >100 MW, which provide LCoE < 20 cEUR/kWh. The integration of solid-state converters within CSP plants can enhance the scalability and economic competitiveness of the whole technology, especially at smaller scales, since the conversion efficiency of solid-state converters weakly depends on the size. Here a system with a high-temperature thermionic energy converter (TEC), together with an optical concentrator designed to be cheap even providing high concentration ratios, is proposed to improve the cost-effectiveness of CSP plants, thus achieving conditions for economic sustainability and market competitiveness. This is possible since TEC can act as a conversion topping cycle, directly producing electricity with a possible conversion efficiency of 24.8% estimated by applying realistic conditions and providing useful thermal flows to a secondary thermal stage. Under established technical specifications for the development of optical concentrator and TEC and according to reasonable economic assumptions, the overall plant conversion efficiency is estimated to be 35.5%, with LCoE of 6.9 cEUR/kW and considering the possibility of an 8 h storage tank for a 1 MW input solar energy system. The calculated projected value is an extremely competitive value compared with other available renewable energy technologies at small capacity scales and opens the path for accelerating the deployment of technological efforts to demonstrate the proposed solution.

Reliability and validity of the Chinese version of the Walsh Family Resilience Questionnaire among community-dwelling disabled elderly individuals (WFRQ-CE).

To test the reliability and validity of the Chinese version of the Walsh Family Resilience Questionnaire among community-dwelling disabled elderly individuals (WFRQ-CE). Convenience sampling was used to select 566 dyads of disabled elderly individuals and their caregivers. The Walsh Family Resilience Questionnaire Chinese Version (WFRQ-C) was tested among elderly individuals. The Family Care Capacity Scale for Elderly Patients (FCCSE) was used as a concurrent validation tool for the caregivers, and the Psychological Resilience Scale (CD-RISC-10), and the Social Support Assessment (SSRS-10) were used as concurrent validation tools for both the elderly individuals and the caregivers. Exploratory factor analysis (EFA) revealed four common factors-"Family belief," "Organization and problem solving," "Family communication," and "Utilization of external resources"-with a cumulative variance contribution rate of 56.94%. Confirmatory factor analysis (CFA) yielded the following fit indices: chi-square/freedom degree (χ2/df) = 2.007, Tucker Lewis index (TLI) = 0.900, incremental fit index (IFI) = 0.917, comparative fit index (CFI) = 0.916, parsimony goodness-of-fit index (PGFI) = 0.681, and root-mean-square error of approximation (RMSEA) = 0.060. The concurrent scales were significantly correlated with the WFRQ-C total score and the scores for each factor (r values between 0.23 and 0.60, P < 0.01). The Cronbach's alpha coefficient was 0.93 for the WFRQ-CE and 0.87, 0.83, 0.89, and 0.65 for the four factors; the retest reliability was 0.96 for the total scale and 0.95, 0.92, 0.92, and 0.95 for the four factors; the split-half reliability was 0.85 for the total scale, and 0.81, 0.78, 0.79, and 0.68 for the four factors. The WFRQ-CE has good reliability and validity among community-dwelling disabled elderly individuals and can be used to evaluate the level of family resilience.

IVFarma LLC in cooperation with Zavod Medsintez LLC extend production of biotechnological drugs for infertility treatment

On November 19, 2022, the production facility manufacturing of biotechnological substances for women's reproductive health was opened at the Zavod Medsintez LLC in Novouralsk. In 2018, Zavod Medsintez LLC, together with IVFarma LLC, has launched industrial-scale operation of the first Russian follicle-stimulating hormone (FSH) drug Primapur® for infertility treatment within the framework of in vitro fertilization (IVF) protocol. Primapur® shows high efficiency, safety and quality not inferior to international analogues. The launch of the new department will substantially increase the capacity and production scale not only of Primapur®, but also other Russian medicines for reproductive health. Moreover, it is also able to provide a decent import substitution and access to world markets.

Selecting optimal R6TX2 intermetallics (R = Gd, Tb, Dy; T = Mn, Fe, Co, Ni; X = Sb, Te) for magnetic refrigeration.

A complete experimental study of the physical properties playing a relevant role in the magnetic refrigeration application (structural, magnetic, magnetocaloric and thermal) has been performed over nine selected Fe2P-type R6TX2 (R = Gd, Tb, Dy; T = Mn, Fe, Co, Ni; X = Sb, Te) intermetallic compounds, to work close to room temperature. Two magnetic phase transitions are observed for these materials: a paramagnetic to ferromagnetic transition in the range of 182-282 K and a spin reorientation transition in the range of 26-76 K. As a consequence, two peaks related to a direct magnetocaloric effect (DMCE) appear with the magnetic entropy change, generating a wide table-like plateau region in between both peaks, which is required to improve the efficiency of refrigerators following an Ericsson cycle. The highest magnetic entropy peak value for μ0ΔH = 5 T is found for Tb2Dy4FeSb2, with 7.72 J kg-1 K-1 around 182 K. For the same applied field the other compounds show moderate values around room temperature (2.88-4.53 J kg-1 K-1). However, the superposition of the two peaks results in huge refrigerant capacity values, up to RCFWHM(5 T) = 1103.04 J kg-1 in the case of Tb2Dy4FeSb2. The thermal diffusivity, thermal effusivity, thermal conductivity and specific heat capacity have been measured at room temperature, and the temperature dependence of the former has been obtained around the relevant magnetic phase transition region, with values in the range of 1.3-2.3 mm2 s-1, which are good for magnetic refrigerators at high working frequencies. The study is completed with a rigorous critical behavior analysis of the second order PM-FM transition. The critical exponent γ points to long range order interactions, in general, while β values are in the range of 0.59-0.90, indicating a deviation from theoretical models as a reflection of the magnetic complexity in these compounds. The critical exponents have been used to confirm the scaling relations of magnetocaloric properties, and the scaling of refrigerant capacity (RC) values in materials exhibiting two magnetic phase transitions is addressed, concluding that for a correct scaling of RC the magnetic entropy change peak must be considered symmetric. The role of each atom in the properties of the compounds is discussed.

Implementasi Sistem Otomasi Order Mentoring Pada Marketplace Mentoring Platform Nusademy

The COVID-19 pandemic has caused the acceleration of digitalization to occur throughout the world in various aspects of life, one of which is in the world of education. The openness of access to learning resources has not been the right solution for humans to learn independently. There are details in the learning process that require the guidance of a teacher called a mentor. In line with this, PT Nusademy Solusi Indonesia (Nusademy) built a marketplace mentoring platform that allows learning to take place in a network between users and mentors. Nusademy provides an opportunity for users to able to choose learning topics and mentors according to their needs. In it, there are steps for mentoring orders, which are currently still being processed manually by the admin every time there is a transaction. So, we need a system that can bridge users with mentors to share benefits without having to depend on admin availability. Python is a programming language that has characteristics suitable for autonomous system development and integration with third-party services. This study aims to create, implement, and test an automated order mentoring system on the Nusademy Web Application which is integrated with the Xendit payment application, the Google Calendar scheduling application, and the Google Hangouts video-conferencing application. The automation system provides automatic services in billing, checking payment status, communication processes between users and admins, communication processes between admins and mentors, creating virtual mentoring rooms, and notification of mentoring agenda reminders. The system is launched on a cloud computing-based server which can enable automatic capacity scaling based on user requests using Google Cloud Run. Testing of the order mentoring automation system is carried out by considering aspects of system capability, system reliability, level of effectiveness, user experience, and business analysis.

Embodied carbon emissions induced by the construction of hydropower infrastructure in China

China has the largest installed hydropower capacity in the world, contributing more than 60% of the national renewable energy supply. In order to respond to climate change, China has constructed many hydropower projects during the past few decades. However, such large scaled infrastructure construction induced a large amount of embodied carbon emissions since many energy-intensive products were consumed. This study aims to account such embodied carbon emissions generated by the construction of hydropower infrastructure in China for a period of 2006–2015 by applying a hybrid method. The results show that the cumulative embodied carbon emissions from conventional hydropower projects and pumped-storage hydropower projects were 1.73E+08 tons and 1.40E+07 tons CO2 respectively. These embodied carbon emissions were mainly generated from construction engineering, electrical equipment, land expropriation and resettlement. Sichuan, Hubei, and Yunnan ranked the top three in terms of such embodied carbon emissions IEA, 2015, while Qinghai had the highest per capita embodied carbon emission. Guangdong and Zhejiang had the largest embodied carbon emissions from pumped storage hydropower projects. Installed capacity scale, location, and input field are three key influential factors on embodied carbon emissions. Finally, several policy recommendations are proposed to help mitigate such embodied carbon emissions by considering the Chinese realities.

Validating the evaluation capacity scale among practitioners in non-governmental organizations.

The growing emphasis on demonstrating the effectiveness of social services through evaluation has heightened demand for nongovernmental organization (NGO) practitioners to enhance evaluation capacity. However, a lack of validated instruments in the NGO context has hampered efforts to assess NGO practitioners' current evaluation capacity and understand how capacity-building activities could be tailored to meet NGO practitioners' actual needs and enhance their evaluation capacity. Hence, this study aims to develop the Evaluation Capacity Scale (ECS), a self-reporting instrument of NGO practitioners' capacity to conduct an effective evaluation of their service programs. Validation data was derived from 439 NGO practitioners who attended the Jockey Club MEL Institute Project in Hong Kong, China. Exploratory factor analysis of the ECS revealed three factors-evaluation mindset, evaluation implementation, and evaluation communication-and confirmatory factor analysis further validated this three-factor structure. Moreover, MANCOVA analysis demonstrated the ECS's predictive validity. Overall, the ECS demonstrated satisfactory convergent validity, high internal consistency reliability, and predictive validity, and its factor structure was supported in subgroups based on gender, age, and level of education. Theoretical and practical implications of the findings are discussed.

Sparse RNNs can support high-capacity classification

Feedforward network models performing classification tasks rely on highly convergent output units that collect the information passed on by preceding layers. Although convergent output-unit like neurons may exist in some biological neural circuits, notably the cerebellar cortex, neocortical circuits do not exhibit any obvious candidates for this role; instead they are highly recurrent. We investigate whether a sparsely connected recurrent neural network (RNN) can perform classification in a distributed manner without ever bringing all of the relevant information to a single convergence site. Our model is based on a sparse RNN that performs classification dynamically. Specifically, the interconnections of the RNN are trained to resonantly amplify the magnitude of responses to some external inputs but not others. The amplified and non-amplified responses then form the basis for binary classification. Furthermore, the network acts as an evidence accumulator and maintains its decision even after the input is turned off. Despite highly sparse connectivity, learned recurrent connections allow input information to flow to every neuron of the RNN, providing the basis for distributed computation. In this arrangement, the minimum number of synapses per neuron required to reach maximum memory capacity scales only logarithmically with network size. The model is robust to various types of noise, works with different activation and loss functions and with both backpropagation- and Hebbian-based learning rules. The RNN can also be constructed with a split excitation-inhibition architecture with little reduction in performance.

Architecting Optically Controlled Phase Change Memory

Phase Change Memory (PCM) is an attractive candidate for main memory, as it offers non-volatility and zero leakage power while providing higher cell densities, longer data retention time, and higher capacity scaling compared to DRAM. In PCM, data is stored in the crystalline or amorphous state of the phase change material. The typical electrically controlled PCM (EPCM), however, suffers from longer write latency and higher write energy compared to DRAM and limited multi-level cell (MLC) capacities. These challenges limit the performance of data-intensive applications running on computing systems with EPCMs. Recently, researchers demonstrated optically controlled PCM (OPCM) cells with support for 5 bits / cell in contrast to 2 bits / cell in EPCM. These OPCM cells can be accessed directly with optical signals that are multiplexed in high-bandwidth-density silicon-photonic links. The higher MLC capacity in OPCM and the direct cell access using optical signals enable an increased read/write throughput and lower energy per access than EPCM. However, due to the direct cell access using optical signals, OPCM systems cannot be designed using conventional memory architecture. We need a complete redesign of the memory architecture that is tailored to the properties of OPCM technology. This article presents the design of a unified network and main memory system called COSMOS that combines OPCM and silicon-photonic links to achieve high memory throughput. COSMOS is composed of a hierarchical multi-banked OPCM array with novel read and write access protocols. COSMOS uses an Electrical-Optical-Electrical (E-O-E) control unit to map standard DRAM read/write commands (sent in electrical domain) from the memory controller on to optical signals that access the OPCM cells. Our evaluation of a 2.5D-integrated system containing a processor and COSMOS demonstrates 2.14 × average speedup across graph and HPC workloads compared to an EPCM system. COSMOS consumes 3.8× lower read energy-per-bit and 5.97× lower write energy-per-bit compared to EPCM. COSMOS is the first non-volatile memory that provides comparable performance and energy consumption as DDR5 in addition to increased bit density, higher area efficiency, and improved scalability.

Feedback-based algorithm for aerial cell's trajectory using deep learning for efficient performance in 6G

Sixth (6th) Generation (6G) wireless communication proposes Non-Terrestrial aerial Network (NTN) architecture to support dynamic scaling of both coverage and capacity. In this paper, we discuss Low Altitude Platform (LAP) based aerial cell for NTN which augments the terrestrial cell through Dual Connectivity (DC) or Carrier Aggregation (CA) on an independent and non-interfering frequency carrier. The determination of an optimal trajectory for a LAP based aerial cell is critical in the deployment for improving its resource utilization within the given flight time. The available literature on selecting trajectory for drone cell have independently considered the data traffic requirements or the mobility of the User Equipment (UE) while improving the throughput or coverage respectively. We propose for the first time; a novel Zone-based Drone Positioning and Trajectory algorithm for selecting UEs to be served by a drone cell as well as for choosing the position and trajectory of the LAP based aerial cell. The proposed algorithm utilizes a new feedback quantity from the UE called Feedback for Aerial Cell Trajectory (FACT), which contains UE's predicted data traffic, traffic preference, and mobility state. The algorithm and FACT are presented mathematically with a combination of closed-form equations with a deep learning (Long Short-Term Memory (LSTM)) model and evaluated through extensive simulations. The simulation shows improvement by 44% in spectrum resource utilization of an aerial cell and a 27% improvement in user throughput over available schemes in the literature.

Construct Validity of the Stroke Upper-Limb Capacity Scale as a Measure of Upper Extremity Capacity

<h3>Research Objectives</h3> The Stroke Upper-Limb Capacity Scale (SULCS) is a standardized assessment of 10 upper extremity (UE) functional tasks, but there are little data on construct validity in acute stroke. Using International Classification of Function definitions, we hypothesize: H1 – a stronger relationship between the SULCS and another activity measure (Functional Independence Measure Selfcare (FIM-SC)), as compared to the SULCS and an impairment measure Motricity Index-UE (MI-UE)); H2 – a stronger association between the SULCS and UE items on the FIM (eating, grooming and bathing (FIM-E, FIM-G, FIM-Ba, respectively)) compared to FIM items not dependent on UE function (walking, bowel and expression (FIM-W, FIM-Bo, FIM-Exp, respectively)). <h3>Design</h3> Cross-sectional. <h3>Setting</h3> Academic inpatient rehabilitation unit. <h3>Participants</h3> N=341/488 (70%) admissions with complete data, age=70±15 years, time post stroke=10±9 days, length of stay=14±8 days, female=47.2%, Admission Total FIM=60±20, Admission SULCS=5.5±3.6, Admission MI-UE=65±35. <h3>Interventions</h3> N/A. <h3>Main Outcome Measures</h3> SULCS, FIM and MI-UE. <h3>Results</h3> H1: SULCS correlated significantly with FIM-SC and MI-UE (ρ=0.74 and ρ=0.85, respectively; (p< 0.001)). H2: SULCS correlated significantly with upper extremity selfcare items (FIM-E/ρ=0.61, FIM-G/ρ=0.56 and FIM-Ba/ρ=0.60), and significantly but more weakly with non-upper extremity items (FIM-Bo/ρ=0.47, FIM-W/ρ=0.57 and FIM-Exp/ρ=0.37). All p< 0.001. <h3>Conclusions</h3> Contrary to H1, SULCS was similarly and strongly correlated with MI-UE and FIM. The inability to compensate for hemiparesis with the intact extremity on both SULCS and MI-UE may explain this unexpected finding. H2 was generally supported, as SULCS demonstrated stronger correlations with UE selfcare items compared to non-UE items. The correlation between SULCS and FIM-W is likely due to hemiparesis in stroke commonly affecting upper and lower extremities. We conclude that SULCS is likely a valid measure of UE capacity early after stroke. <h3>Author(s) Disclosures</h3> The authors declare that they have no relevant conflicts that relate to the research described in this paper.

A scenario-based multi-attribute decision making approach for optimal design of a hybrid off-grid system

For off-grid electrification, hybrid renewable energy power systems have evolved as a more reliable alternative. Solar tracking systems boost PV power generation but come at a high cost, necessitating a thorough investigation of one’s goals before deciding on the type of PV module and power generation approach. A hybrid energy configuration’s optimum design and capacity scaling also necessitates the evaluation of numerous factors, making the choice process extremely complicated. The goal of this research is to conduct a feasibility analysis and design an optimum power system considering a two-step approach, capable of electrifying a rural community in Sierra Leone. In the first step, Hybrid Optimization Model of Multiple Energy Resources (HOMER) software is used to assess feasibility and optimally design the various scenarios, while Multi-attribute Decision Making [(MADM)-Combinative Distance-Based Assessment Algorithm (CODAS)] is used to rank and select the optimum scenario based on technical, economic, and environmental factors. With a net present cost (NPC) of ($471,993), cost of energy (COE)($0.376/kWh), and CO2 of (1.32 kg/yr), SC#2 is the most cost-effective and sustainable scenario. It has a 107 kW PV system, a 30 kW biogas generator, a 38.4 kW converter, and 129 batteries. Results proved that a tracking system is not required for the specified location, and the Sharp ND-250QCS PV module is preferred to the CanadianSolar Dymond PV in attaining the research goal. The decision-making process is validated by comparing the results of three different MADM approaches; CODAS, The Weighted Aggregated Sum Product Assessment (WASPAS), and The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Sensitivity analyses revealed that the optimal scenario is superior and robust, and that its success or triumph is independent of the approach employed in assigning weights to the considered variables.

Allometric Scaling of Anaerobic Capacity Estimated from a Unique Field-Based Data Set of Fish Swimming.

AbstractLocomotion is a defining characteristic that can dictate many aspects of an organism's life history in the pursuit of maximizing fitness, including escaping predators, capturing prey, and transitioning between habitats. Exhaustive exercise can have negative consequences for both short-term and long-term energetics and life history trade-offs, influencing fish survival and reproduction. Studies of swimming performance and exhaustive exercise in fish are often conducted on individual species, but few multispecies analyses exist and even fewer in field settings. In fish, swimming performance and exercise have historically been studied in the laboratory using swim tunnels, but an increasing body of work in recreational fisheries science provides a novel way to examine swimming capacity and exhaustion. Using fight time, the time it takes for a hooked fish to be landed on rod and reel fishing gear, as an opportunistic proxy for fish exhaustion, a multispecies meta-analysis of data from studies on recreational fisheries was conducted to elucidate the factors that most influence capacity for exhaustive exercise. Data from 39 species of freshwater and marine fish were aggregated, and negative binomial mixed effects models as well as phylogenetic least squares regression were used to identify the factors that most influenced exhaustive exercise in the field. Fish total length, aspect ratio of the caudal fin, and body form were significant factors in explaining the capacity for exhaustive exercise. Large migratory fish with high aspect ratios were able to fight, and therefore exercise, the longest. These results illustrate that body form and physiology are both deeply intertwined to inform function across fish species and point to angling fight time as a useful approximation of fish swimming capabilities that can be further developed for understanding the limits of fish exercise physiology.

Fifty Years of Fixed Optical Networks Evolution: A Survey of Architectural and Technological Developments in a Layered Approach

Over the past fifty years, telecommunications has transformed, in an unprecedented manner, the way we live, work and communicate. For telecommunications, fixed networks are the one pillar and wireless networks the other. The wireless networks and their generations have been extensively investigated in the literature; however, the fixed networks lack a consistent exploration of their evolution. For this purpose, our motivation is to present a review of the evolution of fixed networks in a holistic manner, from various different perspectives, which can assist engineers and students to understand, in a better way, how broadband networks developed and the main features of the current networking environment. Specifically, in this review, we aim to shed light on the most important technologies, standards and milestones of the fixed networks from various perspectives, such as the service perspective, the networking perspective (both access and core part) and the physical layer perspective. Our study follows the timeline of the five generations of fixed networks defined by the European Telecommunications Standards Institute (ETSI) F5G group and discusses the key achievements and limitations of each generation for each different infrastructure layer and segment, designating the most important issues for the most widely-adopted technologies and standards. Finally, our analysis helps to reveal the technical challenges that need to be addressed by the fixed telecom network community, such as energy efficiency, capacity scaling, cost-efficiency, etc., while also revealing potential future directions.

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.