Local Storage Research Articles

On the Fundamental Limits of Device-to-Device Private Caching Under Uncoded Cache Placement and User Collusion

In the coded caching problem, as originally formulated by Maddah-Ali and Niesen, a server communicates via a noiseless shared broadcast link to multiple users that have local storage capability. In order for a user to decode its demanded file from the coded multicast transmission, the demands of all the users must be globally known, which may violate the privacy of the users. To overcome this privacy problem, Wan and Caire recently proposed several schemes that attain coded multicasting gain while simultaneously guarantee information theoretic privacy of the users’ demands. In Device-to-Device (D2D) networks, the demand privacy problem is further exacerbated by the fact that each user is also a transmitter, which appears to be needing the knowledge of the files demanded by the remaining users in order to form its coded multicast transmission. This paper shows how to solve this seemingly infeasible problem. The main contribution of this paper is the development of new achievable and converse bounds for D2D coded caching that are to within a constant factor of one another when privacy of the users’ demands must be guaranteed even in the presence of colluding users (i.e., when some users share cached contents and demanded file indices). First, a D2D private caching scheme is proposed, whose key feature is the addition of virtual users in the system in order to “hide” the demands of the real users. By comparing the achievable D2D private load with an existing converse bound for the shared-link model without demand privacy constraint, the proposed scheme is shown to be order optimal, except for the very low memory size regime with more files than users. Second, in order to shed light into the open parameter regime, a new achievable scheme and a new converse bound under the constraint of uncoded cache placement (i.e., when each user stores directly a subset of the bits of the library) are developed for the case of two users, and shown to be to within a constant factor of one another for all system parameters. Finally, the two-user converse bound is extended to any number of users by a cut-set type argument. With this new converse bound, the virtual users scheme is shown to be order optimal in all parameter regimes under the constraint of uncoded cache placement and user collusion.

Optimization of CO2 geological storage sites based on regional stability evaluation—A case study on geological storage in tianjin, china

Carbon dioxide geological storage is one of the important means to mitigate the greenhouse effect and curb global warming. The key to carbon dioxide (CO2) geological storage is to select a suitable storage site. Using the geological analysis method and analytic hierarchy process (AHP)–fuzzy comprehensive evaluation method, combining the qualitative analysis of geological conditions with the quantitative calculation of site parameters, this study determines a site target area suitable for CO2 geological storage in Tianjin. First, the regional crustal stability of Tianjin is discussed, and the characteristics of regional gravity field anomaly, regional crustal thickness, and regional aeromagnetic characteristics are comprehensively analyzed. The site is focused on Banqiao sag, a class ⅳ tectonic unit in Bohai Bay Basin. Second, aiming at the storability, safety, and economy of the site, the expert investigation method is used to construct the target area evaluation index system, including four primary indexes and ten secondary indexes. The weight of each index is determined using the analytic hierarchy process. A two-level fuzzy comprehensive evaluation mathematical model is constructed. The suitability of CO2 geological storage in three sites (site A, site B, and site C) in Banqiao sag is evaluated. The results are as follows: the comprehensive membership of site A, site B, and site C is 0.8629, 0.3926 and 0.1750, respectively. The comprehensive membership of site A is the largest. The evaluation results show that the preferred target area of Tianjin local carbon dioxide geological storage site is located in ‘site A’ near Dazhangtuo fault in Banqiao sag, Huanghua depression, Bohai Bay Basin (with an area of about 5 km2). In this study, a suitable target area is delineated for the local CO2 geological storage site in Tianjin, which can be used as an advantageous location for CO2 geological storage. The conclusion has a positive response to the problem of CO2 emission reduction in Tianjin.

Effects of Different Storage Temperatures on Bacterial Communities and Functional Potential in Pork Meat.

Storage temperature is considered one of the most important factors that affect the microbial spoilage of fresh meat. Chilling and superchilling are the most popular storage techniques on the market, but during transportation, the temperature may reach 10 °C and may even reach room temperature during local retail storage. In the present study, we stored fresh pork meat at different temperatures, −2 °C, 4 °C, 10 °C, and 25 °C. The composition and functional potential of fresh or spoiled meat resident microbes were analyzed based on 16S rRNA gene amplicon sequencing. The microbial composition exhibited high similarity between pork meat stored at −2 °C and 4 °C, with Pseudomonads and Brochothrix being the dominant taxa. Acinetobacter sp., Myroides sp., and Kurthia sp. were markers for spoiled pork meat stored at 25 °C. Both psychrophilic and mesophilic bacteria were observed to grow under a storage temperature of 10 °C, but the overall composition and functional potential based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were found to be similar to that of meat stored at room temperature. Our results broaden the knowledge of possible microbial changes in pork meat during storage, transportation, or retail.

Joint Optimization of Caching Placement and Trajectory for UAV-D2D Networks

With the exponential growth of data traffic in wireless networks, edge caching has been regarded as a promising solution to offload data traffic and alleviate backhaul congestion, where the contents can be cached by an unmanned aerial vehicle (UAV) and user terminal (UT) with local data storage. In this article, a cooperative caching architecture of UAV and UTs with scalable video coding (SVC) is proposed, which provides the high transmission rate content delivery and personalized video viewing qualities in hotspot areas. In the proposed cache-enabling UAV-D2D networks, we formulate a joint optimization problem of UT caching placement, UAV trajectory, and UAV caching placement to maximize the cache utility. To solve this challenging mixed integer nonlinear programming problem, the optimization problem is decomposed into three sub-problems. Specifically, we obtain UT caching placement by a many-to-many swap matching algorithm, then obtain the UAV trajectory and UAV caching placement by approximate convex optimization and dynamic programming, respectively. Finally, we propose a low complexity iterative algorithm for the formulated optimization problem to improve the system capacity, fully utilize the cache space resource, and provide diverse delivery qualities for video traffic. Simulation results reveal that: i) the proposed cooperative caching architecture of UAV and UTs obtains larger cache utility than the cache-enabling UAV networks with same data storage capacity and radio resource; ii) compared with the benchmark algorithms, the proposed algorithm improves cache utility and reduces backhaul offloading ratio effectively.

Microbiome and Metabiotic Properties of Kefir Grains and Kefirs Based on Them.

—The analysis of the literature on the microbiome composition and metabolic properties of kefir available at the RSCI and Web of Science was carried out. Kefir has been used by humans for centuries. It is a useful product of mixed lactic and alcoholic fermentation, produced using evolutionally established associative cultures, collected in an aggregated state termed kefir grains. General characterization of kefir grains from the territorial zones of different continents (Russia, Europe, Asia, and America) is provided. The methods for differentiation and identification of individual species are described, as well as their interactions within the community. The diversity of microbial composition of kefir grains depending on local cultivation conditions and storage processes is shown. The microorganisms present in kefir have a number of properties that determine their metabolism, interaction in the community, beneficial effects on human health and immune system, which is important for the prevention and control of bacterial and viral infections, especially during the COVID-19 pandemic.

An investigation into heat storage by adopting local climate zones and nocturnal-diurnal urban heat island differences in the Tokyo Prefecture

• Urban heat island diurnal-nocturnal difference adopted as relative heat storage indicator. • Seasonal local climate zone (LCZ) and relative heat storage correlation is analyzed. • Relative height slope data is combined with LCZs for heat storage analysis. • Higher-rise LCZs are suggested to have larger relative heat storage effects than lower-rise. • Compact LCZs are suggested to have larger relative heat storage effects than open. This study aims to identify urban forms that are prone to heat storage in the Tokyo Prefecture in Japan. First, local climate zones (LCZ) were identified with 100 m pixel resolution using Landsat 8 data. LCZs include urban forms that are predominantly defined by building compactness and height. The spatial distribution of urban heat island intensity was obtained using LCZs and MODIS 100 m resolution land surface temperatures from 2013 to 2021. The difference between diurnal and nocturnal heat island intensity (∆UHI) was evaluated as an indicator of the relative heat storage effect between the LCZs. Lower ∆UHIs suggest increased relative heat-storage capacities. Seasonal average ∆UHIs for compact and super high-rise, high-rise, mid-rise, and low-rise LCZs were 3.1 °C, 4.1 °C, 5.8 °C, and 8.3 °C, respectively. Additionally, ∆UHIs for open and super high-rise, high-rise, and mid-rise LCZs were 5.8 °C, 6.4 °C, and 7.8 °C, respectively. Slope data also validated the LCZ height. LCZ and slope analyzes found lower ∆UHI magnitudes in all LCZs with high-rise buildings. Also, compact LCZs had lower ∆UHI magnitudes than open LCZs at corresponding heights. Therefore, higher-rise and compact LCZs are suggested to have larger relative heat storage effects than lower-rise and open LCZs.

Blockchain-Based Secure Data Storage Protocol for Sensors in the Industrial Internet of Things

The Industrial Internet of Things (IIoT) that introduces Internet of Things (IoT) technology into industrial environments is beneficial to construct smart factories. It utilizes various sensors to collect the data of industrial devices. These data are analyzed to improve the manufacturing efficiency and product quality. Cloud storage provides a solution for storing data outsourced, especially for sensors that have limited local storage and computational capacity. To ensure the privacy preserving of devices, the collected data should be stored in the formal ciphertext. Therefore, encrypted data sharing should be implemented to analyze the devices’ data. In this article, the cloud storage solution for sensors is considered. To achieve a secure and efficient data storage and sharing, a novel group signature scheme, which has less computation overhead and communication overhead, is designed to realize anonymous authentication first. And then, a novel blockchain-based cloud storage protocol for sensors in IIoT is constructed on basis of the proposed group signature scheme. Smart contract and proxy re-encryption are utilized in this protocol to realize secure data sharing with a less computational overhead. Furthermore, security proofs and performance evaluations demonstrate that this protocol is secure, privacy-preserving, and has at least 40% and 20% performance improvement in data storage and sharing phase, respectively.

Verifiable Keyword Search Supporting Sensitive Information Hiding for the Cloud-Based Healthcare Sharing System

With the integration of the healthcare system, Internet of Things, and cloud storage service, more and more medical institutions upload their electronic medical records (EMRs) to the cloud to reduce the local storage burden and realize data sharing among external researchers. To secure the sensitive information, EMRs usually should be encrypted before being stored on the cloud. However, the existing searchable encryption schemes that encrypt the entire EMRs can hide the sensitive information, but this results in the shared EMRs being unable to be used by researchers. In addition, if the queried and extracted EMRs are incorrect, it will lead to misdiagnosis and even endanger the patient’s life. In order to solve the aforementioned problems, in this article, we propose a verifiable keyword search scheme supporting sensitive information hiding for the cloud-based healthcare sharing system. The sensitive information is encrypted, while other contents in EMR can be shared among users in this scheme. Doctors and researchers can quickly perform search operations based on keywords to extract the EMRs they require. This time complexity is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$O(n)$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n$</tex-math></inline-formula> is the number of attribute values in the record. But the sensitive information is hidden for the researchers. Furthermore, the correctness of EMRs can be verified when they are extracted from the cloud. This time complexity is max <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lbrace O(n^{\prime }),O(N^{\prime })\rbrace$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n^{\prime }$</tex-math></inline-formula> is the number of query keywords and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N^{\prime }$</tex-math></inline-formula> is the number of the retrieved records. We expound the security and carry out experiments to estimate the efficiency of the proposed scheme.

BEST-Blockchain-Enabled Secure and Trusted Public Emergency Services for Smart Cities Environment.

In the last few years, the Internet of things (IoT) has recently gained attention in developing various smart city applications such as smart healthcare, smart supply chain, smart home, smart grid, etc. The existing literature focuses on the smart healthcare system as a public emergency service (PES) to provide timely treatment to the patient. However, little attention is given to a distributed smart fire brigade system as a PES to protect human life and properties from severe fire damage. The traditional PES are developed on a centralised system, which requires high computation and does not ensure timely service fulfilment. Furthermore, these traditional PESs suffer from a lack of trust, transparency, data integrity, and a single point of failure issue. In this context, this paper proposes a Blockchain-Enabled Secure and Trusted (BEST) framework for PES in the smart city environment. The BEST framework focuses on providing a fire brigade service as a PES to the smart home based on IoT device information to protect it from serious fire damage. Further, we used two edge computing servers, an IoT controller and a service controller. The IoT and service controller are used for local storage and to enhance the data processing speed of PES requests and PES fulfilments, respectively. The IoT controller manages an access control list to keep track of registered IoT gateways and their IoT devices, avoiding misguiding the PES department. The service controller utilised the queue model to handle the PES requests based on the minimum service queue length. Further, various smart contracts are designed on the Hyperledger Fabric platform to automatically call a PES either in the presence or absence of the smart-home owner under uncertain environmental conditions. The performance evaluation of the proposed BEST framework indicates the benefits of utilising the distributed environment and the smart contract logic. The various simulation results are evaluated in terms of service queue length, utilisation, actual arrival time, expected arrival time, number of PES departments, number of PES providers, and end-to-end delay. These simulation results show the effectiveness and feasibility of the BEST framework.

A Substantiation and Key Agreement Based on Unidentified Identity for Peer-to-Peer Cloud

Abstract: Real-time data collected by smart sensors deployed in factories is shared over open channels as the Industrial Internet of Things (IIoT) expands, posing a risk of unauthorised access to transmitted messages by adversaries, resulting in a privacy leakage problem. However, users frequently find it difficult to backup all data from the original cloud servers to their mobile phones in order to upload the downloaded data to the new cloud provider due to insufficient local storage and computational capabilities. To address this issue, it is proposed to gather information on the available solutions for the application of security issues in peer-to-peer networks, with a focus on authentication mechanisms.

A blockchain-based dynamic and traceable data integrity verification scheme for smart homes

A smart home system composed of numerous smart devices has benefited people’s life due to the feature of convenience. With the development of smart home technology, huge amounts of data stored on external servers flow between different smart devices, and the integrity of these data is of great importance to the security of smart home systems. In this paper, we propose a blockchain-based data integrity verification scheme that supports efficient dynamic operations for a smart home system. In the verification scheme, we utilize the home gateway (HG) to aggregate all the data information and design a data structure that can be efficiently and dynamically operated to store the tag information of the data, which can reduce the local storage pressure in smart home systems. Moreover, homomorphic verifiable tags are used to formulate verification strategies and record the interactions between HG, cloud service providers (CSP), and third-party auditor (TPA) on the blockchain to make the verification service traceable and useful. Then, the theoretical analysis and experiments prove that the scheme is effective and cost-acceptable in smart home systems.

The Development of an IoT-based Indoor Air Monitoring System Towards Smart Energy Efficient Classroom

Indoor air quality has become a crucial issue, specifically during COVID 19 pandemic. The good indoor air quality will lead to occupants’ comfort condition, thus affecting their productivity. Indoor air temperature and relative humidity are two essential components of thermal comfort. This paper presents the development of a temperature and relative humidity monitoring system for the classroom using the Internet of Things (IoT). This system consists of three main components: logger nodes, a gateway logger, and an interconnected cloud server. The logger node (ESP8266 / ESP32 microcontroller and DHT22 sensor) is a device at the edge of the IoT system and is placed at the monitoring location. The logger gateway is built on a Raspberry Pi 4, which serves as an intermediate server. It receives periodic data (temperature and humidity) from the logger nodes through the publish-subscribe MQTT protocol and sends it to the MongoDB Atlas cloud database. The logger gateway saves all received logs into the SQLite database as temporary local storage and then uploads the data to the MongoDB Atlas cloud at a predefined interval. The MongoDB data is then displayed on a monitoring dashboard using MongoDB charts. The logger node with the DHT22 sensor has been adjusted using a linear model and successfully tested to monitor indoor and outdoor air conditions with satisfactory results. The recorded data has also been successfully modeled using the Gaussian Mixture Model and a simple Fuzzy model. These models can capture the dynamic of air condition in the room and predict the state of the cooling system.

An arbitrable multi‐replica data auditing scheme based on smart contracts

SummaryIn order to improve the availability and persistence of data, lightweight cloud users want to store multiple‐replicas of the original file on the server with less local computing and storage overhead. Meanwhile, to ensure the integrity of the remote storage data, some schemes have been designed to allow public verification. However, most existing schemes only focus on malicious cloud service providers and ignore the possibility that dishonest users cheat for profit. This article implements an arbitrable data auditing scheme under multi‐replica storage. The scheme adopts a new arbitration mechanism under multi‐replica storage, makes use of the non‐tampering characteristics of smart contracts, carries out reliable verification through miners, and realizes the timely detection and punishment of any fraudulent entity. In addition, the scheme also designs a multi‐replica storage model based on the B* tree, realizes the batch verification of replica blocks, enables the fraud behavior of malicious users to be identified after data update, and improves the space utilization efficiency. The article also gives detailed security proof of the proposed scheme. The evaluation result shows our scheme not only realizes a more practical and fairer audit scheme but also has lower computational overhead than current state‐of‐the‐art multi‐replica arbitrable schemes.

(Invited) Lithium-Based Components Integrated on Silicon: Disruptive, Promising and Credible Solutions for 5G & Beyond

Following a trend similar to Moore’s low which prevailed for decades for active circuits, RF integrated passive components have reinvented themselves over the years in order to sustain continuous performance and size requirements. Their roadmap is still unrolling, thanks to a wide variety of new materials integration: high-k dielectrics for capacitors[1] ,[2] , magnetic material for inductors [3], aluminium nitride[4] (now scandium doped) for RF filters, or more recently phase-change materials for RF switches[5].In the last few years, RF integrated passives built upon Lithium-based materials have attracted strong attention because of their state-of-the-art performances and their direct integration on silicon wafers. Lithium-based piezoelectric materials are used since 40 years by the SAW filters industry, which processes LiTaO3 (LTO) or LiNbO3 (LNO) bulk wafers in dedicated fabs. Recently, however, layered SAW devices exploiting thin films of these materials directly on a silicon wafer have exhibited dramatically improved performances. These devices leverage the latest developments in single crystal Li-based layer transfer, or in deposition techniques (PVD, ALD[6], Pulse-Laser-Deposition, ...) of epitaxial, textured, or amorphous Li-based thin films, all of which achievable in industrial grade semiconductor equipments.In this presentation, we will give an overview of the potential of integrating lithium-based materials on silicon through different examples of promising RF components for 5G. First, we will show how the availability of Li-based Piezoelectric-on-Insulator (POI) wafers[7] is a game changer for 5G filtering. We will present very promising perspectives regarding the development of LNO-based Bulk Acoustics Wave filters (BAW)[8] ,[9],[10] which aim at extending the application space of POI SAW filters towards the upper 5G bands and even Wi-Fi 6E [5-7 GHz] . Different examples of Li-based materials integrations will be given3,4,5,[11] . Secondly, we will discuss the potential of a new type of Li-based hybrid micro supercapacitors integrated on silicon. LiPON thin films offer a unique combination of dual properties, being both a dielectric and an electrolyte[12]. Their integration on silicon is not only bringing potentially ultra-high capacitance densities, but also local on-chip energy storage for 5G components, opening a new paradigm in use of the device in a system[13] ,[14] . After that, we will open the horizon of the potential of Li-based materials integration towards other types of RF devices, like RF switchs, and elaborate on their synergy with Li-transistors for neuromorphic applications[15] and with more conventional lithium microbatteries integrated on silicon[16]. Finally, the integration of Lithium in a silicon industrial environment and the remaining challenges will be discussed. The similarities and discrepancies of the different Li-based processes will be analyzed as well as the compatibility with a silicon CMOS and/or microsystem fab, and the potential for wafers size scaling. Risks like sensitivity to humidity and potential Li contamination will be outlined with some relevant preventive protocols in order to make the Lithium integration on silicon a real and credible disruptive solution regarding 5G challenges. [1] F. Roozeboom, et al. ECS 2007 [2] M. Bousquet et al., ECAPD 2014 [3] J. P. Michel et al., IEEE Trans. Magnetics 55, n°7, pp. 1-7 (2019) » [4] A. Reinhardt et al., IFCS 2011 [5] A. Leon et al., IEEE Trans. Microwave Theory and Techniques, vol. 68, n°1, pp. 60-73 (2020)” [6] M. Bedjaoui et al. ECS Meeting (October 10-14, 2021). [7] E. Butaud et al. IEDM 2020 [8] M. Bousquet et al., Proc. IEEE International Ultrasonics Symposium 2019. [9] M. Bousquet et al., Proc. IEEE International Ultrasonics Symposium 2020. [10] A. Reinhardt et al., Proc. Joint Conference of EFTF & IFCS 2021 [11] L. Sauze et al, Thin solid films, 726, may 2021 [12] L. Le Van-Jodin et al, Solid State ionic, 2013 [13] V. Sallaz et al, Journal of Power Source, 2020 [14] V. Sallaz et al. submitted to ECS 2021 [15] N-A Ngyuen et al,” submitted to ECS 2021 [16] S. Oukassi et al, IEDM 2019

Personal Health Metrics Data Management Using Symmetric 5G Data Channels

The integrated collection of personal health data represents a relevant research topic, which is enhanced further by the development of next-generation mobile networks that can be used in order to transport the acquired medical data. The gathering of personal health data has become recently feasible using relevant wearable personal devices. Nevertheless, these devices do not possess sufficient computational power, and do not offer proper local data storage capabilities. This paper presents an integrated personal health metrics data management system, which considers a virtualized symmetric 5G data transportation system. The personal health data are acquired using a client application component, which is normally deployed on the user’s mobile device, regardless it is a smartphone, smartwatch, or another kind of personal mobile device. The collected data are securely transported to the cloud data processing components, using a virtualized 5G infrastructure and homomorphically encrypted data packages. The system has been comprehensively assessed through the consideration of a real-world use case, which is presented.

FOLDER SYSTEM ORGANIZER USING WEB DEVELOPMENT

This paper gives an overview of the web technologies. The general idea of the new version of the HTML5, CSS and JS and other tools which is presented in this paper is the formal specifications and the establishment of uniform solutions for technologies and functionalities which have been for the computer users for the easily access of the files storage so that they can make their folder and files easily and by using one extension. The extension use the support of the node js. The structure and styling will be done in the HTML and CSS respectively. The complex features like adding the file or folder in the project will be done by JavaScript(JS). The main aim of this paper is to make have one extension which that will make the folders of the individual types of the files like documents, excels, pdfs, videos etc. The extension will automatically will make the folder and the files will go in that folder according to their type automatically. At last, I can conclude you saying that File System organizer will be very helpful and will make our work easy. Keywords— local storage, organizing files

The protection of commodified data in e-platforms

Using limited information, notably excluding paramount items in e-platforms, the user leads to sub-optimal decisions regarding his/her data to digital commodes. Thus, the study statement: personal data has been commodified. The study uses a method the mitigation of data commodification risk. It aims to find a way for data protection when a person uses e-platforms. It is important because user's attributes that allow others to recognize each other are closely aligned with a person's being, and individuals identify themselves through these attributes. As such, they are essential to personhood and warrant protection. The personality of user in e-platforms must be dignity - inalienable.&#x0D; Based on the GDPR Article 25 and Recital 78, the measure for the data protection is assumed to comply when data systems go along with technical and organizational safeguards. The EU's concept advances a new legal approach where users are holders of their data. It allows them to manage data in secure, local, and online storage orderliness, dispensing it by person's choice. Selves are capable to select settings for data execution and data accord. This mitigation technique acknowledges a human-centric distinction and increased e-platforms for empowered designs. It can also guard against unlawful profiling techniques that strive to circumvent critical measures for the risk mitigation of data commodification. The solution is found aground in the experience of e-platforms such as Mydex, NextCloud, and MyData Global. In this regard, the article defends the digital integrity in e-platforms through data protection by design, informed consent, and the prohibition in e-platforms to consider data - a source of financial gain. The conclusion would remain to go along with data accuracy, time reservation, and user informativeness.

PF-ClusterCache: Popularity and Freshness-Aware Collaborative Cache Clustering for Named Data Networking of Things

Named Data Networking (NDN) has been recognized as the most promising information-centric networking architecture that fits the application model of IoT systems. In-network caching is one of NDN’s most fundamental features for improving data availability and diversity and reducing the content retrieval delay and network traffic load. Several caching decision algorithms have been proposed; however, retrieving and delivering data content with minimal resource usage, reduced communication overhead, and a short retrieval time remains a great challenge. In this article, we propose an efficient popularity and freshness caching approach named PF-ClusterCache that efficiently aggregates the storage of different nodes within a given cluster as global shareable storage so that zero redundancy be obtained in any cluster of nodes. This increases the storage capacity for caching with no additional storage resource. PF-ClusterCache ensures that only the newest, most frequent data content is cached, and caching is only performed at the edge of the network, resulting in a wide diversity of cached data content across the entire network and much better overall performance. In-depth simulations using the ndnSIM simulator are performed using a large transit stub topology and various networking scenarios. The results show the effectiveness of PF-ClusterCache in sharing and controlling the local global storage, and in accounting for the popularity and freshness of data content. PF-ClusterCache clearly outperforms the benchmark caching schemes considered, especially in terms of the significantly greater server access reduction and much lower content retrieval time, while efficiently conserving network resources.

Spatial and temporal considerations of implementing local renewable energy sources and decentralised heat recovery for domestic heat

A UK case study area containing over 33,000 households has been used to investigate spatial and temporal conflicts in meeting domestic heat demand through renewable electrical energy supply and low-grade decentralised heat recovery from the urban drainage network. The case study area was selected as its water infrastructure and population density were representative of the conditions experienced by the majority of the UK's urban population. The findings suggest that adopting an optimised and integrated water-energy system would lead to a 60% reduction in current carbon emissions, compared to a natural gas based system. The integrated water-energy system proposed for domestic heating showed an annual surplus of renewable energy of 716 GWh. However, a non-renewable source of energy of 114 GWh is required to deal with the intermittency of the demand and renewable energy supply. Given the renewable surplus, it would be possible to eliminate carbon emissions from domestic heating with the addition of local low efficiency inter-seasonal energy storage. Taking a broader perspective, the calculated 60% carbon emission saving is significant as the domestic housing sector contributes 15% of the UK carbon emissions. A progressive adoption of such locally based schemes throughout the country would be able to make tangible reductions to national carbon emission targets. • Quantified spatio-temporal patterns of energy supply and heat demand 33,000 households. • Optimised integrated water-energy system reduced domestic heating CO 2 emissions by 60%. • Considerable annual surplus of renewable energy and low-grade heat given heat demand. • Sub daily energy supply-demand imbalances occur throughout whole year. • Relatively low-efficiency thermal energy storage could mitigate imbalance.

Methods for comparing and improving the quality of local storage of grapes in Uzbekistan

In this article, several methods of storing the harvest of the grape varieties in a natural way, including storage, vine method, storage in water-filled containers (by the method of legumes) were studied. During the experiments, discrepancy between their quality indicators, advantages and disadvantages of these methods, storage periods and conditions, as well as the amount of dry matter, the amount of nitrate, the pH environment were researched and analyzed. The pertinent results showed that the sugar content of grapes was the lowest according to the characteristics of varieties in the vine method, accounted for 16.3% and the highest in the storage method, which was 21.17 %, the amount of nitrate was not more than 60 mg/kg in the norm, which was also allowed in all methods. Noteworthy, the most acceptable method among them was the bottle method, however, the method needed to be improved in the future.