Multiplet relative location approach and waveform correlation correction and their application

The theory and method of relative location technique were described in the paper. The travel-time difference equa-tions for five phases (Pg, Sg, P11, S11 and Pn) were given. By using the multiplet relative location approach and wave correlation correction, the aftershock cluster of the Shunyi earthquake occurred on December 16, 1996 was relocated. The depth calculation was constrained by using multiple seismic phases. The relocation results were compared with that from traditional absolute location techniques.

Privacy-Preserving Relative Location Based Services for Mobile Users

Location-aware applications have been used widely with the assistance of the latest positioning features in Smart Phone such as GPS,AGPS,etc.However,all the existing applications gather users' geographical data and transfer them into the pertinent information to give meaning and value.For this kind of solutions,the user's privacy and security issues might be raised because the geographical location has to be exposed to the service provider.A novel and practical solution is proposed in this article to provide the relative location of two mobile users based on their WiFi scanned results without any additional sensors.There is no privacy concern in this solution because end users will not collect and send any sensitive information to the server.This solution adopts a Client/Server(C/S) architecture,where the mobile user as a client reports the ambient WiFi APs and the server calculates the distances based on the WiFi AP's topological relationships.A series of technologies are explored to improve the accuracy of the estimated distance and the corresponding algorithms are proposed.We also prove the feasibility with the prototype of "Circle Your Friends" System(CYFS) on Android phone which lets the mobile user know the distance between him and his social network friends.

Leveraging tuberculosis case relative locations to enhance case detection and linkage to care in Swaziland

Background:In Swaziland,as in many high HIV/TB burden settings,there is not information available regarding the household location of TB cases for identifying areas of increased TB incidence,limiting the development of targeted interventions.Data from“Butimba”,a TB REACH active case finding project,was re-analyzed to provide insight into the location of TB cases surrounding Mbabane,Swaziland.Objective:The project aimed to identify geographical areas with high TB burdens to inform active case finding efforts.Methods:Butimba implemented household contact tracing;obtaining landmark based,informal directions,to index case homes,defined here as relative locations.The relative locations were matched to census enumeration areas(known location reference areas)using the Microsoft Excel Fuzzy Lookup function.Of 403 relative locations,an enumeration area reference was detected in 388(96%).TB cases in each census enumeration area and the active case finders in each Tinkhundla,a local governmental region,were mapped using the geographic information system,QGIS 2.16.Results:Urban Tinkhundla predictably accounted for most cases;however,after adjusting for population,the highest density of cases was found in rural Tinkhundla.There was no correlation between the number of active case finders currently assigned to the 7 Tinkhundla surrounding Mbabane and the total number of TB cases(Spearman rho=−0.57,p=0.17)or the population adjusted TB cases(Spearman rho=0.14,p=0.75)per Tinkhundla.Discussion:Reducing TB incidence in high-burden settings demands novel analytic approaches to study TB case locations.We demonstrated the feasibility of linking relative locations to more precise geographical areas,enabling data-driven guidance for National Tuberculosis Programs’resource allocation.In collaboration with the Swazi National Tuberculosis Control Program,this analysis highlighted opportunities to better align the active case finding national strategy with the TB disease burden.

Reputation-Based Hierarchically Cooperative Spectrum Sensing Scheme in Cognitive Radio Networks

Cooperative spectrum sensing in cog- nitive radio is investigated to improve the det- ection performance of Primary User （PU）. Meanwhile, cluster-based hierarchical coop- eration is introduced for reducing the overhead as well as maintaining a certain level of sens- ing performance. However, in existing hierar- chically cooperative spectrum sensing algo- rithms, the robustness problem of the system is seldom considered. In this paper, we pro- pose a reputation-based hierarchically coop- erative spectrum sensing scheme in Cognitive Radio Networks （CRNs）. Before spectrum sensing, clusters are grouped based on the location correlation coefficients of Secondary Users （SUs）. In the proposed scheme, there are two levels of cooperation, the first one is performed within a cluster and the second one is carried out among clusters. With the reputa- tion mechanism and modified MAJORITY rule in the second level cooperation, the pro- posed scheme can not only relieve the influ- ence of the shadowing, but also eliminate the impact of the PU emulation attack on a rela- tively large scale. Simulation results show that, in the scenarios with deep-shadowing or mul- tiple attacked SUs, our proposed scheme ach- ieves a better tradeoff between the system robustness and the energy saving compared with those conventionally cooperative sensing schemes.

Relocating ruptures of two M6 earthquakes in Zhongba, South-central Tibet in 2004 and 2005 with seismological and geodetic methods

To better understand repeatability of strong earthquakes in previously ruptured zones during one seismogenic period, we studied the rupture zones of the doublet of M6 earthquakes in Zhongba region of southcentral Tibet, China, in 11 July 2004 and 7 April 2005, respectively. We focused on the overlapping degree of two strong quakes’ aftershock areas one week after the mainshocks by using the SQH station in China Seismic Network and a 68-stations temporary broadband seismic array, a part of the international HI-CLIMB project. About 115 local earthquakes were recorded in one week after the mainquakes, and we located these earthquakes by master event relative location （MERL） method. We also used this method to relocate 31 other M3.7 ＋ earthquakes from 1 July 2004 to 1 July 2005. Meanwhile, we studied two mainshocks’ coseismic ruptures with satellite interferometric synthetic aperture radar （InSAR）. Our results show that the ruptured zones of the two earthquakes do not overlapp substantially, either from early aftershock data or from InSAR inversions.

Relative locations of operated semigroups subwords in free and Motzkin words

Bracketed words are basic structures both in mathematics （such as Rota-Baxter algebras） and mathematical physics （such as rooted trees） where the locations of the substructures are important. In this paper, we give the classification of the relative locations of two bracketed subwords of a bracketed word in an operated semigroup into the separated, nested, and intersecting cases. We achieve this by establishing a correspondence between relative locations of bracketed words and those of words by applying the concept of Motzkin words which are the algebraic forms of Motzkin paths.