Aggregate Utility Research Articles

Trends in utilization of reflectance confocal microscopy in the United States, 2017-2019

Trends in utilization of reflectance confocal microscopy in the United States, 2017-2019

Valorization of calcined coal gangue as coarse aggregate in concrete

Coal gangue is a by-product generated from coal mining and washing. Using coal gangue as aggregate is an effective approach of valorization this high-volume industrial waste, not only solving the environmental issue of accumulation but also reducing the mining of natural aggregate. However, compared to natural aggregate, the strength of coal gangue aggregate (CGA) is much lower, and its interfacial bonding in concrete is weaker. This paper studies the effect of calcination processes at 450 °C and 750 °C on the mineral and chemical compositions, microstructure and suitability of coal gangue as aggregate in concrete manufacturing. Water absorption, mechanical properties and interface structure of four concretes containing the original, 450 °C-calcined (CGA450), 750 °C-calcined (CGA750) and calcined-selected coal gangue aggregates (CGAs) were comparatively investigated. Experimental results show that the crushing index of the calcined CGAs decreases but water absorption increases. The interface of concrete prepared by CGA450 is porous, and its water absorption is significantly increased. Crushing index of CGA750 is 6.0% lower than that of original CGA, and the water absorption is increased by 3.9%. Because of thermal activation of Si and Al components on the surface, CGA750 can significantly improve the strength and interface structure in concrete. This study provides a theoretical guidance and technical support for the large-scale and high-value utilization of coal gangue coarse aggregates in concrete industry.

Improving Aggregate Utility and Service Differentiation of IEEE 802.11ah Restricted Access Window Mechanism Using ANFIS

Improving Aggregate Utility and Service Differentiation of IEEE 802.11ah Restricted Access Window Mechanism Using ANFIS

Effects of pre-treated on dura shell and tenera shell for high strength lightweight concrete

The utilization of bio-based renewable lightweight aggregates with pre-treated coating methods, using a grout binder derivative of water/cement (w/c: 1.25), is a recent development meant to enhance the performance of high strength and lightweight concrete. It aims to promote the long-term sustainability in the field of concrete technology. In this experimental analysis, coated tenera shells (CTS) and coated dura shells (CDS) acted as a replacement for tenera shells (TS) and dura shells (DS), respectively. It has previously been investigated in terms of its physical strength and associated material properties, as a lightweight bio-based aggregate concrete (LWBAC). The results revealed that through the substitution of raw TS and DS aggregates with that of CTS and CDS, the density of the samples which fell within the range of high strength lightweight concrete (HSLWC), slightly increased. As a result, the workability of the oil palm shell concrete (OPSC) showed a significant improvement by almost 41% with the use of the pre-treated OPS aggregates, as compared to the non-treated OPSC. The strength of the HSLWCs with the CDS mixture achieved the highest compressive strength and modulus of elasticity at 28-days, which were recorded at 52 MPa and 17.1 GPa, respectively. The ultrasonic pulse velocity (UPV) was also assessed, and the outcome revealed that a good condition was attained after 7 days. Therefore, pre-treated CDS and CTS has proven to be a highly recommended, eco-friendly aggregate, which serves as an alternative solution to improve the properties of OPS aggregates, and substantially enhance the performance of the LWBAC.

The paradox of thrift in a two‐sector Kaleckian growth model

AbstractWe analyze the paradox of thrift in a two‐sector Kaleckian growth model. We consider an economy with one consumption and one investment good, differential sectoral mark‐ups and profit rates equalization. We show that when the investment function depends on aggregate capacity utilization and on the aggregate profit share (the Bhaduri–Marglin investment function) the paradox of thrift in its growth version may fail if mark‐ups are higher in the investment good sector. In this case, an increase in the saving rate produces a reallocation of economic activity toward the investment good sector; the aggregate profit share rises and its positive effect on investment may offset the reduction in average capacity utilization if investment is relatively more sensitive to profitability than to the level of activity.

Role of Artificial Aggregates of Fly Ash and Slag Concretes At Different Water-To-Cement Ratios in Mechanical and Permeability Behavior

This study presents an experimental investigation on the effect of artificial aggregate utilization fracture and permeability properties of concretes. For this, two types of artificial aggregates, namely, artificial fly ash aggregate (AFA) from cold bonding agglomeration process of fly ash and Portland cement and artificial slag aggregate (ASA) from cold bonding agglomeration process of ground granulated blast furnace slag and Portland cement, were replaced with natural aggregate as coarse aggregate. Moreover, to investigate the influence of water-to-cement ratio, three different water-to-cement ratios of 0.35, 0.45, and 0.55 were considered in the concrete production. The concretes were tested for the mechanical property in terms of as compressive strength, modulus of elasticity, and splitting, net flexural strength, and fracture energy and also permeability property such as water sorptivity, water penetration, gas permeability, and resistance to chloride ion penetration. The test results were also analyzed by means of statistical technique, namely, GLM-ANOVA. It was found that the use of cold bonded fly ash and slag aggregates were very effective on the performance characteristics of concretes depending on w/c ratio.

Spending and Out-of-Pocket Prices for Brand-Name Drugs Among Commercially Insured Individuals in Massachusetts, 2015-2017

This cross-sectional study analyzes data on aggregate utilization and aggregate spending by patients and by pharmacy benefit managers to pharmacies for every brand-name drug prescription dispensed to all fully insured patients and some self-insured patients with commercial insurance in Massachusetts from 2015 to 2017.

The Impact of Multiple Sclerosis Disease Status and Subtype on Hematological Profile.

Multiple sclerosis (MS) is an immune-mediated, demyelinating disease of the central nervous system. In this study, an MS cohort and healthy controls were stratified into Caucasian and African American groups. Patient hematological profiles—composed of complete blood count (CBC) and complete metabolic panel (CMP) test values—were analyzed to identify differences between MS cases and controls and between patients with different MS subtypes. Additionally, random forest models were used to determine the aggregate utility of common hematological tests in determining MS disease status and subtype. The most significant and relevant results were increased bilirubin and creatinine in MS cases. The random forest models achieved some success in differentiating between MS cases and controls (AUC values: 0.725 and 0.710, respectively) but were not successful in differentiating between subtypes. However, larger samples that adjust for possible confounding variables, such as treatment status, may reveal the value of these tests in differentiating between MS subtypes.

PH-Driven formation of soy peptide nanoparticles from insoluble peptide aggregates and their application for hydrophobic active cargo delivery

The insoluble soy peptide aggregates formed upon proteolysis are generally considered as “ready to be discarded”, which placed additional burden on related industries. In this study, with the aim of promoting sustainable utilization of these large aggregates, novel soy peptide-based nanoparticles (SPN) were successfully fabricated from these aggregates via a controlled pH-shifting method, and the obtained SPN exhibited good storage stability and antioxidant activity. Furthermore, the pH-shifting process also provided a driven force for loading and delivering curcumin, which significantly improved its water solubility (up to 105 folds), storage and simulated gastric-intestinal digestive stability, as well as in vitro bioavailability and antioxidant activity. These results indicated that controlled pH-shifting could be an effective and facile method to trigger the assembly of insoluble aggregates into functional peptide nanoparticles for the delivery of bioactive cargoes, which provided a new strategy for the sustainable and high-value application of these low-value peptide byproducts.

Regional shocks and the formation of interconnected markets: A network approach

We examine the strategic incentives of a set of regions, inhabited by risk-averse agents, to form interconnected markets to: (i) diversify the risk arising from random shocks to endowments, and (ii) gain from exchange. We characterize the equilibrium architecture of interconnected markets. Of particular import is the issue of heterogeneity, and we characterize the equilibrium size and composition of interconnected markets with respect to heterogeneity in variances and covariances of shocks across regions. We then compare the equilibrium architecture of interconnected markets to that derived from a pure risk diversification mechanism such as income-sharing. We also characterize the efficient architecture that maximizes aggregate utility.

A sustainability-oriented framework for the application of industrial byproducts to the base layers of low-volume roads

Roadway engineering works typically rely on the utilization of natural aggregates as building materials. However, growing pressures for sustainable roads are highlighting the importance of replacing virgin materials with industrial byproducts. Constructors worldwide are trying to select optimum soil-byproduct mixtures that have a fair trade-off between engineering properties, environmental impacts and material costs. This requires a multi-objective analysis to explore feasible mixtures that honor a set of preferences to mathematically identify the best compromised soil-byproduct mixture. In this paper, a sustainability-oriented framework is proposed for selecting optimum soil-byproduct proportions for unbound base layers of unpaved roads. A compromise programming tool is implemented to select a mixture that is statistically preferred over mixtures with different byproduct contents. The method is illustrated using technical, economic and environmental indicators that are easily measurable. Investigations are performed for different decision-making perspectives including the constructor’s, contractor’s and the environment’s viewpoints. Two byproducts from the steel industry are mixed in different proportions from 50% to 80% by weight with a clayey soil. The optimum mixture was obtained at a proportion of 70% byproduct and 30% clay. Monte Carlo simulations and sensitivity analysis of transport scenarios further supported this conclusion. Results demonstrate that mixture selection based only on strength properties provides inadequate optimum from a sustainable standpoint. The proposed framework can help road constructors incorporate environmentally-friendly materials in a cost-effective way, while maintaining the technical quality of base layers.

Elastic FemtoCaching: Scale, Cache, and Route

The advent of elastic Content Delivery Networks (CDNs) enable Content Providers (CPs) to lease cache capacity on demand and at different cloud and edge locations in order to enhance the quality of their services. This article addresses key challenges in this context, namely how to invest an available budget in cache space in order to match spatio-temporal fluctuations of demand, wireless environment and storage prices. Specifically, we jointly consider dynamic cache rental, content placement, and request-cache association in wireless scenarios in order to provide just-in-time CDN services. The goal is to maximize the an aggregate utility metric for the CP that captures both service benefits due to caching and fairness in servicing different end users. We leverage the Lyapunov drift-minus-benefit technique and Jensen's inequality to transform our infinite horizon problem into hour-by-hour subproblems which can be solved without knowledge of future file popularity and transmission rates. For the case of non-overlapping small cells, we provide an optimal subproblem solution. However, in the general overlapping case, the subproblem becomes a mixed integer non-linear program (MINLP). In this case, we employ a randomized cache lease method to derive a scalable solution. We show that the proposed algorithm guarantees the theoretical performance bound by exploiting the submodularity property of the objective function and pick-and-compare property of the randomized cache lease method. Finally, via real dataset driven simulations, we find that the proposed algorithm achieves 154% utility compared to similar static cache storage-based algorithms in a representative urban topology.

Multi-stage hierarchical channel allocation in UAV-assisted D2D networks: A stackelberg game approach

UAV-assisted D2D networks can provide auxiliary communication for areas with poor communication facilities by using the characteristics of easy deployment of unmanned aerial vehicle (UAV), then it becomes a promising technology. However, the coexistence of UAV and D2D aggravates the conflict of spectrum resources. In addition, when the UAV performs the communication service, it will in-evitably cause the location change, which will make the original channel allocation no longer applicable. Inspired by the influence of frequent channel switching on channel allocation, we define the communication utility as a tradeoff between the throughput and channel switching cost. In the considered model, we investigate the multi-stage hierarchical spectrum access problem with maximizing aggregate communication utilities in UAV-assisted D2D networks. In particular, due to the hierarchical feature of the considered network, we adopt Stackelberg game to formulate this spectrum access problem where both the throughput and channel switching cost are considered. We prove that the proposed game has a stable Stackelberg equilibrium (SE), and the heterogeneous network based channel allocation (HN-CA) algorithm is proposed to achieve the desired solution. Simulation results verify the validity of the proposed game and show the effectiveness of the HN-CA algorithm.

MIXTURE OF CONSISTENT STOCHASTIC UTILITIES AND A PRIORI RANDOMNESS

The purpose of this paper is to develop an explicit construction of consistent utilities, using the stochastic flows approach developed in El Karoui & Mrad (2013, 2020). Starting from a family of utility functions indexed by some parameter [Formula: see text] (for example, the risk aversion coefficient or any other parameter), the idea is to randomize [Formula: see text] and to construct nonstandard stochastic utility processes. Two approaches are developed. The first one consists of building directly from the class [Formula: see text] a global utility [Formula: see text] as a sup-convolution. The second approach which is very different, consists to define from the class [Formula: see text] of monotonic optimal processes, associated with the class [Formula: see text], a global pair [Formula: see text] as a mixture. The nonstandard stochastic utility is then obtained by composing stochastic flows and is interpreted as the aggregate utility of all considered agents.

Multi-Timescale QoE Provisioning for Adaptive Video Streaming in Heterogeneous Deployments

This paper considers an optimization problem that maximizes an aggregate utility, formulated as the weighted geometric mean of the “in-context” suitability of a set of radio access technologies (RATs), to support adaptive video streaming subject to the existence of legacy data transfers. Motivated by the unfeasibility of solving the formulated problem centrally when the various RATs are loosely integrated (i.e., at core network (CN) level), a hybrid (i.e., network-assisted user-driven) strategy is devised to approximate its optimum solution. Unlike previous hybrid approaches, the proposed methodology exploits network assistance to ensure a friendly co-existence between adaptive video streaming clients and legacy users. It operates on different timescales, where the fastest timescale operation is performed on the video clients according to a policy that is tuned by the network on slower timescales. The user operation on the fastest timescale (i.e., tens of ms) enables to adapt video streaming depending on the perceived quality-of-experience (QoE) and local components of the context (e.g., remaining credit and battery level). A small-cell tuning on a slower timescale (i.e., hundreds of ms) enables to preempt the resources used by legacy users based on the operating conditions (e.g., load and type of scheduler). Finally, a tuning performed by the network on the slowest timescale (i.e., few seconds) offloads legacy data transfers to unlicensed bands whenever the amount of interference on licensed bands reaches critical levels, which helps to sustain good QoE for all video clients. A cost-benefit analysis reveals that the proposed methodology performs closely to its centralized counterpart with much less control overhead on the radio interface.

Environmental impact, durability performance, and interfacial transition zone of iron ore tailings utilized as dam concrete aggregates

This paper discusses the utilization of iron ore tailing aggregates (IOTA) as a replacement for normal aggregates (NA) in dam concrete for hydraulic engineering applications. The durability performance of concrete prepared using IOTA and NA, including resistance to chloride-ion permeability, sulfate corrosion resistance, and abrasion-erosion resistance, are investigated in this study. Based on it, the interfacial transition zone (ITZ) characteristics of IOTA and NA samples are examined by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and microscopic nanoindentation. Besides, the economic and environmental evaluations of the IOTA utilization in real hydraulic engineering are proposed. The results show the concrete prepared with IOTA has more superior durability than NA. The abrasion resistance of concrete prepared with IOTA is higher than that of the NA sample by 1.32–2.90 h m2/kg. Since the IOTA raw rock has higher compressive strength, lower saturated-surface-dry (SSD) water absorption, and angular shape, the concrete prepared with IOTA has more superior ITZ characteristics and durability performance than NA. Significant economic and environmental benefits of the utilization of IOTA in hydraulic engineering are obtained. The investments into the IOTA utilization in two practical hydraulic engineering applications can save 8.98 × 106 USD. It can also reduce the occupied land space, CO2 emission, and water consumption by 151 900 m2, 8157.0 t, and 942 000 m3. The relative reductions of CO2 emission and water consumption, as compared to NA, are 15.7 and 27.4%.

Joint RAN Slicing and Computation Offloading for Autonomous Vehicular Networks: A Learning-Assisted Hierarchical Approach

In this paper, a two-timescale radio access network (RAN) slicing and computing task offloading problem is investigated for a cloud-enabled autonomous vehicular network (C-AVN). We aim at jointly maximizing the communication and computing resource utilization with diverse quality-of-service (QoS) guarantee for autonomous driving tasks. Specifically, to capture the small-timescale network dynamics, a computing task scheduling problem is formulated as a stochastic optimization program, for maximizing the long-term network-wide computation load balancing with minimum task offloading variations. Due to the large problem size and unavailable network state transition probabilities, we employ cooperative multi-agent deep <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> -learning (MA-DQL) with fingerprint to solve the problem by learning the set of stationary task offloading policies with stabilized convergence. Given the task offloading decisions, we further study a RAN slicing problem in a large timescale, which is formulated as a convex optimization program. We focus on optimizing the radio resource slicing ratios among base stations, to maximize the aggregate network utility with statistical QoS provisioning for autonomous driving tasks. Based on the impact of radio resource slicing on computation load balancing, we propose a two-timescale hierarchical optimization framework to maximize both communication and computing resource utilization. Extensive simulation results are provided to demonstrate the effectiveness of the proposed framework in comparison with state-of-the-art schemes.

Resource Allocation in Communication Networks with Large Number of Users: The Dual Stochastic Gradient Method

We consider a communication network with a fixed set of links that are shared by a large number of users. The resource allocation is performed on the basis of the aggregate utility maximization in ...

Aggregates in aquatic ecosystems and implications for aquacultures

Agglomerations of suspended particulate matter serve various roles in aquatic ecosystems. They participate in nutrient and energy fluxes and are involved in important food web processes. While comprehensive studies on aggregates are available from natural freshwater and marine ecosystems, little is known about the roles of aggregates in aquacultures, particularly in shrimp pond farming. As particle-rich systems, shrimp ponds and marine aquaculture (mariculture) areas constitute interesting objects for aggregate studies, particularly as a source of natural feed, particle fluxes, microbial communities, including pathogenic bacteria, and possible vector of disease widespread. The aims of this review are i) to compile the current knowledge on the role of aggregates in aquatic ecosystems, particularly in aquaculture areas covering advantages and negative side effects of aggregates in aquacultures, ii) to explore the role of aggregates in disease ecology, and iii) perspective of aquaculture management in the context of aggregate utilization and management. Since Southeast Asia, especially Indonesia, is among the most important regions for aquaculture activities, this review focuses on Indonesian aquacultures. Although aquacultures produce important amounts of aggregates, including its associated microbial communities, they are rarely investigated in Indonesian aquacultures, particularly in shrimp pond farming. In contrast, most of the studies focused on bacterial cultivation and utilization of isolates for aquacultures. Thus, understanding the ecological roles of aggregates in aquacultures may support the improvement of aquaculture management and yields.

Application of Sensors for Streetlight Automation in Industry and Energy Conservation – A Case Study

Sustainable development of the country is possible by adapting various energy conservation measures. Energy conservation helps in using energy in effectivemanner. Application of advanced technology and improved operation and maintenance practices contributes towards energy conservation. Smart streetlight framework is an essential piece of the smart city, which represents 10-40% aggregate power utilization in the city. In this paper the energy audit report is presented for streetlights in the industry and also presented various energy conservation measures with the help of sensors and automation. It was observed that Passive Infra-red (PIR) sensor helps a lot in saving energy where movement of people is low.