The 802.11ax standard final specification is expected in 2019, however first parameters are just released. The target of the new standard is four times improvement of the average throughput within the given area. This standard is dedicated for usage in dense environment such as stadiums, means of municipal communication, conference halls and others. The main target is to support many users at the same time with the single access point. The question arises if the new standard will have higher throughput then previous ones in the single user mode. The author calculated the maximal theoretical throughput of the 802.11ax standard and compared the results with the throughput of older 802.11 standards such as 802.11n and 802.11ac. The new he-wifi-network example included in the ns-3.27 release of the NS-3 simulator was used to simulate the throughput between the access point and the user terminal. The results indicate that in some conditions the 802.11ac standard has higher throughput than the new 802.11ax standard.
A significant part of hard coal production (15–19% in the years 2010–2017, i.e. 1.0–1.3 billion
tons per year) is traded on the international market. The majority of coal trade takes place by sea,
accounting for 91–94% of the total coal trade. The article discusses the share of coal in international
seaborne trade and the largest coal ports. Coal is one the five major bulk commodities (in addition
to iron ore, grain, bauxite, alumina, and phosphate rock). In the years 2010–2016, the share of coal
in international seaborne trade and major bulk commodities was 36–41% and 11–12%, respectively.
Based on the analysis of coal throughput in different ports worldwide, the ports with the
largest throughput include the ports of Qinhuangdao (China), Newcastle (Australia), and Richards
Bay (South Africa). For 2013–2017, their throughput amounted to a total of 411–476 million tons
of coal. The largest coal exporting countries were: Australia, Indonesia, Russia, Colombia, South
Africa, and the US (a total of 85% share in global coal exports), while the largest importers are
Asian countries: China, India, Japan, South Korea and Taiwan (a 64% share in global imports). In
Europe, Germany is the largest importer of coal (54 million tons imported in 2016). The article also
discusses the freight costs and the bulk carrier fleet. Taking the price of coal at the recipient’s (i.e.
at the importer’s port) into account, the share of freight costs in the CIF price of steam coal (the
price of a good delivered at the frontier of the importing country) was at the level of 10–14%. In
the years 2010–2016, the share of bulk carriers in the world fleet was in the range of 11–15%. In
terms of tonnage, bulk carriers accounted for 31–35% of the total tonnage of all types of ships in
the world. The share of new (1–4 years) bulk carriers in the total number of ships on a global scale
in the years 2010–2016 was 29–46%.
Cloud radio access network (C-RAN) has been proposed as a solution to reducing the huge cost of network upgrade while providing the spectral and energy efficiency needed for the new generation cellular networks. In order to reduce the interference that occur in C-RAN and maximize throughput, this paper proposes a sequentially distributed coalition formation (SDCF) game in which players, in this case the remote radio heads (RRHs), can sequentially join multiple coalitions to maximize their throughput. Contrary to overlapping coalition formation (OCF) game where players contribute fractions of their limited resources to different coalitions, the SDCF game offers better stability by allowing sequential coalition formation depending on the availability of resources and therefore providing a balance between efficient spectrum use and interference management. An algorithm for the proposed model is developed based on the merge-only method. The performance of the proposed algorithm in terms of stability, complexity and convergence to final coalition structure is also investigated. Simulation results show that the proposed SDCF game did not only maximize the throughput in the C-RAN, but it also shows better performances and larger capabilities to manage interference with increasing number of RRHs compared to existing methods.
The welfare and healthy growth of poultry under intensive feeding conditions are closely related to their living environment. In spring, the air quality considerably decreases due to reduced ventilation and aeration in cage systems, which influences the meat quality and health of broilers during normal growth stages. In this study, we analyzed the airborne bacterial communities in PM2.5 and PM10 in cage broiler houses at different broiler growth stages under intensive rearing conditions based on the high-throughput 16S rDNA sequencing technique. Our results revealed that PM2.5, PM10 and airborne microbes gradually increased during the broiler growth cycle in poultry houses. Some potential or opportunistic pathogens, including Acinetobacter, Pseudomonas, Enterococcus, Microbacterium, etc., were found in the broiler houses at different growth stages. Our study evaluated variations in the microbial communities in PM2.5 and PM10 and potential opportunistic pathogens during the growth cycle of broilers in poultry houses in the spring. Our findings may provide a basis for developing technologies for air quality control in caged poultry houses.
Orthogonal frequency division multiple access (OFDMA) in Long Term Evolution (LTE) can effectively eliminate intra-cell interferences between the subcarriers in a single serving cell. But, there is more critical issue that, OFDMA cannot accomplish to decrease the inter-cell interference. In our proposed method, we aimed to increase signal to interference plus noise ratio (SINR) by dividing the cells as cell center and cell edge. While decreasing the interference between cells, we also aimed to increase overall system throughput. For this reason, we proposed a dynamic resource allocation technique that is called Experience-Based Dynamic Soft Frequency Reuse (EBDSFR). We compared our proposed scheme with different resource allocation schemes that are Dynamic Inter-cellular Bandwidth Fair Sharing FFR (FFRDIBFS) and Dynamic Inter-cellular Bandwidth Fair Sharing Reuse-3 (Reuse3DIBFS). Simulation results indicate that, proposed EBDSFR benefits from overall cell throughput and obtains higher user fairness than the reference schemes.
Here we investigate the microbiomes of the soil samples from the Yamal Peninsula (the surroundings of Salekhard city, Russian Federation) using a high-throughput sequencing approach. The main goal was to investigate the impact of mining on soils within the following regeneration, both during the reclamation practice and natural self-growth. Several quarries were studied, engaged in sand, clay and chromatic ores mining. The taxonomic analysis of the soil microbiomes revealed 50 bacterial and archaeal phyla; among the dominant phyla were: Proteobacteria, Actinobacteria, Acidobacteria, Chroloflexi, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, Bacteroidetes, AD3, and Nitrospirae. Compared to the typical tundra soil, which was chosen as a control, the disturbed soils had increased biodiversity and total counts for soil bacteria, archaea, and fungi, especially in the cryosolic horizon. The different mining strategies caused significantly different transformations of soil microbiomes, which was less pronounced for self-growth compared to reclaimed quarries. This isolation of the reclaimed quarry was mainly associated with the increase of the amount of acidobacteria (fam. Koribacteraceae and Acidobacteriaceae and order Ellin6513), some proteobacterial taxa (fam. Syntrophobacteraceae), and Chloroflexi (fam. Thermogemmatisporaceae). The study also revealed bacteria, which tend to be specific for marine tundra environments: gemmatimonadetes from the order N1423WL and Chloroflexi bacteria from the order Gitt-GS-136.
A novel non-orthogonal multiple access (NOMA) scheme is proposed to improve the throughput and the outage probability of the cognitive radio (CR) inspired system which has been implemented to adapt multiple services in the nextgeneration network (5G). In the proposed scheme, the primary source (PS) had sent a superposition code symbol with a predefined power allocation to relays, it decoded and forwarded (DF) a new superposition coded symbol to the destination with the other power allocation. By using a dual antenna at relays, it will be improved the bandwidth efficiency in such CR NOMA scheme. The performance of the system is evaluated based on the outage probability and the throughput with the assumption of the Rayleigh fading channels. According to the results obtained, it is shown that the outage probability and throughput of the proposed full-duplex (FD) in CR-NOMA with reasonable parameters can be able deploy in practical design as illustration in numerical results section.
The dual core bit-byte CPU must be equipped with properly designed circuits, providing interface between the two processor units, and making it possible to exploit all its advantages like versatility of the byte unit and speed of the bit unit. First of all, the interface circuits should be designed in such a way, that they dont disturb maximally parallel operation of the units, and that the CPU as a whole works in the same manner as in a standard PLC. The paper presents hardware solutions supporting effective operation of PLC CPU-s. Possibilities of solving problems concerning data exchange between a CPU and peripheral circuits were presented, with a special stress on timers and counters, and also on data exchange between the bit unit and the byte unit. The objective of the proposed solutions is to decrease the time necessary for a CPU to access its peripheries.