Blockchain-Based Secure Authentication Scheme for Medical Data Sharing

Data security is vital for medical cyber physical system (MCPS). The decentralization feature of blockchain is helpful to solve the problem that the secure authentication process is highly dependent on the trusted third party and implement data security transmission. In this paper, the blockchain technology is used to describe the security requirements in authentication process. A network model of MCPS based on blockchain is proposed. Through analysis of medical data storage architecture, data was ensured not to be tampered and trackable. The security threat was eliminated by bilinear mapping in the authentication process of medical data providers and users. The credibility problem of the trusted third party was avoided and the two-way authentication was realized between the hospital and blockchain node. The security analysis and performance test were carried out to verify the security and related performance of the authentication protocol. The results show that the MCPS based on blockchain realizes medical treatment data sharing, and meets safety requirements in the security authentication phase.

Creep anisotropy behavior,deformation mechanism,and its efficient suppression method in Inconel 625 superalloy

Mill products,such as sheets,usually show obvious anisotropy in their mechanical properties,which greatly affects both their applications and workability.In this study,the orientation-dependent tensile and creep behaviors of Inconel 625 alloy sheets with weak local textures were systematically investigated at 650°C.The results showed that Inconel 625 superalloy exhibits nearly isotropic tensile properties;how-ever,obvious creep anisotropy appears when loading along different directions.Creep life in the rolling direction(150±5 h)was approximately 4.5 times longer than in the transverse direction(33±1 h).Se-vere creep anisotropy was found to be determined by two aspects:(i)the change in deformation mecha-nisms along the rolling direction(a combination of boundary sliding,dislocation slipping,and twinning)and the transverse direction(dislocation slipping).Stronger impingement of slip bands on grain bound-aries accelerated intergranular crack initiation and propagation during loading along the transverse direc-tion,which resulted in a short creep life.(ii)The differences in strain compatibility at grain boundaries(i.e.,creep loading along the transverse direction resulted in the initial grains forming strong Brass,Cu,and S textures).Creep cracks preferentially nucleated at the junctions between Cu/Brass texture grains,as these interfaces exhibit the worst strain compatibility(Luster-Morris parameter m≤0.22).Furthermore,pre-stress aging(PSA)treatment is proposed as an efficient method to suppress creep anisotropy.The discrepancy rate of creep life was found to be reduced by nearly 50%after PSA treatment.

Progress toward the sustainable development of world cultural heritage sites facing land-cover changes

The quantification of the extent and dynamics of land-use changes is a key metric employed to assess the progress toward several Sustainable Development Goals(SDGs)that form part of the United Nations 2030 Sustainable Development Agenda.In terms of anthropogenic factors threatening the conservation of heritage properties,such a metric aids in the assessment of achievements toward heritage sustainability solving the problem of insufficient data availability.Therefore,in this study,589 cultural World Heritage List(WHL)properties from 115 countries were analyzed,encompassing globally distributed and statistically significant samples of“monuments and groups of buildings”(73.2%),“sites”(19.3%),and“cultural landscapes”(7.5%).Land-cover changes in the WHL properties between 2015 and 2020 were automatically extracted from big data collections of high-resolution satellite imagery accessed via Google Earth Engine using intelligent remote sensing classification.Sustainability indexes(SIs)were estimated for the protection zones of each property,and the results were employed,for the first time,to assess the progress of each country toward SDG Target 11.4.Despite the apparent advances in SIs(10.4%),most countries either exhibited steady(20.0%)or declining(69.6%)SIs due to limited cultural investigations and enhanced negative anthropogenic disturbances.This study confirms that land-cover changes are among serious threats for heritage conservation,with heritage in some countries wherein the need to address this threat is most crucial,and the proposed spatiotemporal monitoring approach is recommended.

UAV Laser scanning technology:a potential cost-effective tool for micro-topography detection over wooded areas for archaeological prospection

Airborne laser scanning(ALS)has recently been identified as a potential tool in topographic mapping for archaeological prospection.However,most existing applications in this field refers to manned ALS systems,for which the high operation and maintenance costs limits its application in small-scale archaeological investigation.In this paper,we conducted an exploratory study on the application of the unmanned aerial vehicle(UAV)laser scanning(ULS)system in ancient micro-topography detection over wooded areas.Compared with manned ALS technology,we analyzed the advantages and potentials of ULS technology for archaeological applications.Then we outlined existing mainstream survey-grade UAV-based laser scanners,data processing and visualization approaches.Furthermore,we performed case studies in three cultural heritage sites in Zhejiang Province,China using two representative mainstream survey-grade ULS systems.Results were then verified by an in-site investigation.Finally,the correct selection of ULS devices,the planning of data acquisition missions and the use of appropriate data processing methods specifically for archaeological prospection were discussed.This paper provides a cost-effective and flexible solution for micro-topography detection in wooded areas.ULS technology,as demonstrated here,can be an important supplement to existing archaeological investigation methods,particularly for small-scale areas,and has promising prospects in archaeological applications.

Land use/cover and landscape pattern changes in Manas River Basin based on remote sensing

Large-scale water and soil development in inland river basins in arid areas has made changes in landscape composition and structure,threatening the ecological balance.In order to study the trend of land use/cover and landscape pattern change and its relationship with water resources utilization in Manas River Basin,the land-use data of five periods in 1976,1990,2000,2010 and 2015 were analyzed.The results showed that:(1)During 1976-2015,farmland and construction land continuously increased,forest land and grassland continuously decreased,the water area initially reduced and then increased,the area of saline-alkali land initially increased and then reduced,the overall trend of unused land and the sandy area was decreasing and the area of different time periods is floating.The areas of land-use types either increased or decreased.This indicates that the landscape pattern of the basin changes dramatically,and human activities are the main reasons for this phenomenon;(2)The oasis area increased from 3480.2 km2 in 1976 to 7982.0 km2 in 2015,with an obvious increasing trend.The oasis area clearly increased during 1976-1990,the growth rate was 40.6%,the growth rate of the oasis area was 129.4%.In the last 40 years,the degree of desertification fluctuated and decreased.The increase of the oasis area directly leads to the increase of water resources utilization and aggravates the degree of water resources shortage;(3)The pattern of land-use types showed a non-equilibrium trend.In the region with increasing landscape heterogeneity,the overall landscape pattern was increasingly controlled by the majority of patches.The intensive land management model and drip irrigation under mulch have improved the utilization efficiency of water resources and saved water resources from engineering renovation and irrigation management.

A novel image-fusion method based on the un-mixing of mixed MS sub-pixels regarding high-resolution DSM

A major reason for the spectral distortions of fused images generated by current image-fusion methods is that the fused versions of mixed multispectral(MS)sub-pixels(MSPs)corresponding to panchromatic(PAN)pure pixels remain mixed.The MSPs can be un-mixed spectrally to pure pixels having the same land cover classes in a fine classification map during the fusion process.Since it is difficult to produce such a land cover classification map using only MS and PAN images,a Digital Surface Model(DSM)derived from airborne Light Detection And Ranging data were employed in this study to facilitate the classification.In a novel fusion method proposed in this paper,MSPs near and across boundaries between vegetation and non-vegetation are identified using MS,PAN,and normalized Digital Surface Model(nDSM).The identified MSPs then are fused to pure pixels with respect to the corresponding land cover class in the classification map.In a test on WorldView-2 images over an urban area and the corresponding nDSM,the fused image generated by the proposed method was visually and quantitatively compared with fused images obtained using common image-fusion methods.The fused images generated by the proposed method yielded minimal spectral distortions and sharpened boundaries between vegetation and non-vegetation.

Multi-frequency satellite radar imaging of cultural heritage:the case studies of the Yumen Frontier Pass and Niya ruins in the Western Regions of the Silk Road Corridor

Synthetic Aperture Radar(SAR)remote sensing is increasingly favoured in archaeological applications.However,the effectiveness of this technology for archaeological prospection has so far not been fully assessed.In this study,an integrated single-date and multi-temporal SAR data-processing chain was proposed to sharpen archaeological signs and hence their detection and monitoring.In total,14 scenes of X-band Cosmo-SkyMed,C-band Sentinel-1 and L-band PALSAR data covering the Western Regions of the Silk Road Corridor in China were employed for two important archaeological sites including the Yumen Frontier Pass with emerging archaeological traces and Niya ruins with subsurface remains.The results pointed out that single-date satellite radar data were useful for the identification of subsurface traces buried under desert in the landscape-scale,whereas for the identification of emerging monuments,Sentinel-1 was limited by its lower spatial resolution compared to TerraSAR and PALSAR data.Multi-date products,such as interferometric coherence,the averaged radar signatures and RGB multi-temporal composites,were effective to sharpen archaeological traces as well as for change detection in Yumen Frontier Pass.This study presents a pilot assessment of satellite SAR data for the analysis and monitoring of archaeological features in the predominantly arid-sandy environmental characteristic of investigated sites.

Remote sensing-based deformation monitoring of pagodas at the Bagan cultural heritage site,Myanmar

As a World Cultural Heritage site with sacred landscape featuring an exceptional range of Buddhist art and architecture,much attention has been focused on the sustainable development of Bagan(Myanmar).Particularly,the monitoring of landscape surface subsidence and monument instability is of great importance to the protection and development planning of the Bagan heritage site.In this study,we applied high resolution TerraSAR-X imagery acquired from 2019 to 2020 for deformation monitoring based on the small baseline subset(SBAS)and persistent scatterer synthetic aperture radar interferometry(PSInSAR)approaches.We identified several hotspots and pagodas with displacement anomalies linked to land cover change and previous earthquakes.The cross comparison between SBAS and PSInSAR and the precision of height estimates derived by PSInSAR indicated a millimetric precision of the derived deformation products.The combination of the two multi-temporal SAR interferometry approaches satisfies the two-scale monitoring requirements from landscapes to monuments,particularly for large-scale World Heritage sites.The non-contact monitoring method has potential when traditional methods using field accessibility and surveillance are constrained.

Archeological crop marks identified from Cosmo-SkyMed time series: the case of Han-Wei capital city, Luoyang, China

The development of spaceborne Synthetic Aperture Radar(SAR)technology declares that the golden era of SAR remote sensing in archeology is approaching;however,nowadays its methodology framework is still lacking due to the inadequate case studies validated by ground-truths.In this study,we investigated the crop marks using multi-temporal Cosmo-SkyMed data acquired in 2013 by applying a twostep decision-tree classifier in conjunction with a spatial analysis in an area of archeological interest nearby the archeological site of Han-Wei capital city(1900–1500 BP),in Luoyang,China.The time-series backscattering anomalies related to the wheat growth cycle were identified and then further validated in two zones by geophysical investigations(Ground Penetration Radar and electrical measurements)and in a third zone by archeological excavations made after the SAR data acquisition.This study provides a new approach for the relic detection,shallowly buried and covered by the crop vegetation,by temporal crop marks on spaceborne SAR images.We also emphasize the necessity to establish a satellite-to-ground methodology framework for the promotion of remote-sensing technology in archeology.