scholarly journals Exchanging registered users’ submitting reviews towards trajectory privacy preservation for review services in Location-Based Social Networks

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256892
Author(s):  
Yunfeng Wang ◽  
Mingzhen Li ◽  
Yang Xin ◽  
Guangcan Yang ◽  
Qifeng Tang ◽  
...  
Keyword(s):  
Social Networks ◽  
Privacy Preservation ◽  
User Profile ◽  
User Selection ◽  
The Real ◽  
Statistical Attack ◽  
Correlation Attack ◽  
The Difference ◽  
Location Based Social Networks

In Location-Based Social Networks (LBSNs), registered users submit their reviews for visited point-of-interests (POIs) to the system providers (SPs). The SPs anonymously publish submitted reviews to build reputations for POIs. Unfortunately, the user profile and trajectory contained in reviews can be easily obtained by adversaries who SPs has compromised with. Even worse, existing techniques, such as cryptography and generalization, etc., are infeasible due to the necessity of public publication of reviews and the facticity of reviews. Inspired by pseudonym techniques, we propose an approach to exchanging reviews before users submit reviews to SPs. In our approach, we introduce two attacks, namely review-based location correlation attack (RLCA) and semantic-based long-term statistical attack (SLSA). RLCA can be exploited to link the real user by reconstructing the trajectory, and SLSA can be launched to establish a connection between locations and users through the difference of semantic frequency. To resist RLCA, we design a method named User Selection to Resist RLCA (USR-RLCA) to exchange reviews. We propose a metric to measure the correlation between a user and a trajectory. Based on the metric, USR-RLCA can select reviews resisting RLCA to exchange by suppressing the number of locations on each reconstructed trajectory below the correlation. However, USR-RLCA fails to resist SLSA because of ignoring the essential semantics. Hence, we design an enhanced USR-RLCA named User Selection to Resist SLSA (USR-SLSA). We first propose a metric to measure the indistinguishability of locations concerning the difference of semantic frequency in a long term. Then, USR-SLSA can select reviews resisting SLSA to exchange by allowing two reviews whose indistinguishability is below the probability difference after the exchange to be exchanged. Evaluation results verify the effectiveness of our approach in terms of privacy and utility.

Towards privacy preservation for “check-in” services in location-based social networks

2019 ◽  
Vol 481 ◽  
pp. 616-634 ◽  
Author(s):  
Gang Sun ◽  
Liangjun Song ◽  
Dan Liao ◽  
Hongfang Yu ◽  
Victor Chang
Keyword(s):  
Social Networks ◽  
Privacy Preservation ◽  
Location Based Social Networks

scholarly journals From Information to Message: Archaeology and Media in Serbia

2016 ◽  
Vol 9 (3) ◽  
pp. 609
Author(s):  
Jasna Vuković ◽  
Miroslav Vujović
Keyword(s):  
Social Networks ◽  
Social Relevance ◽  
The Real ◽  
The Public ◽  
The Past ◽  
The Media ◽  
The Subject ◽  
Real Truth ◽  
Insufficient Knowledge

The paper discusses the image of archaeology and archaeologists created in the public by various media. On the grounds of analysis of the texts in which the subject of archaeology figures in newspapers and on social networks, it is demonstrated that archaeologists are mainly perceived in the public as inert “concealers” of the real truth of the past. The reason behind this is equally in the insufficient knowledge of the media, but as well in the reluctance of professional archaeologists to communicate. The paper offers an outline of long-term strategy to bridge the existing gap and inform the public about the mission and social relevance of the discipline.

scholarly journals LoCaTe: Influence Quantification for Location Promotion in Location-based Social Networks

2017 ◽  
Author(s):  
Ankita Likhyani ◽  
Srikanta Bedathur ◽  
Deepak P
Keyword(s):  
Social Networks ◽  
State Of The Art ◽  
Kernel Density ◽  
Mobility Model ◽  
User Mobility ◽  
Density Estimates ◽  
Kernel Density Estimates ◽  
Time Gap ◽  
Location Based Social Networks

Location-based social networks (LBSNs) such as Foursquare offer a platform for users to share and be aware of each other’s physical movements. As a result of such a sharing of check-in information with each other, users can be influenced to visit (or check-in) at the locations visited by their friends. Quantifying such influences in these LBSNs is useful in various settings such as location promotion, personalized recommendations, mobility pattern prediction etc. In this paper, we focus on the problem of location promotion and develop a model to quantify the influence specific to a location between a pair of users. Specifically, we develop a joint model called LoCaTe, consisting of (i) user mobility model estimated using kernel density estimates; (ii) a model of the semantics of the location using topic models; and (iii) a model of time-gap between check-ins using exponential distribution. We validate our model on a long-term crawl of Foursquare data collected between Jan 2015 Feb 2016, as well as on publicly available LBSN datasets. Our experiments demonstrate that LoCaTe significantly outperforms state-of-the-art models for the same task.

Hidden “holes” in the capital of banks and the supply of credit to the real sector of economy

2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov
Keyword(s):  
Credit Risk ◽  
The Other ◽  
Real Sector ◽  
Capital Management ◽  
Loan Loss ◽  
Short Term ◽  
The Real ◽  
Ex Post ◽  
The One

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.

A Problem of Long - Term Digital Preservation: Difference in Humanities and Natural Sciences

2014 ◽  
Vol 3 ◽  
pp. 183-195
Author(s):  
Elena Macevičiūtė
Keyword(s):  
Social Sciences ◽  
Digital Preservation ◽  
Dynamic Activity ◽  
Private Companies ◽  
Time Line ◽  
Digital Documents ◽  
Whole Process ◽  
The Difference ◽  
Technological Science

The article deals with the requirements and needs for long-term digital preservation in different areas of scholarly work. The concept of long-term digital preservation is introduced by comparing it to digitization and archiving concepts and defined with the emphasis on dynamic activity within a certain time line. The structure of digital preservation is presented with regard to the elements of the activity as understood in Activity Theory. The life-cycle of digitization processes forms the basis of the main processing of preserved data in preservation archival system.The author draws on the differences between humanities and social sciences on one hand and natural and technological science on the other. The empirical data characterizing the needs for digital preservation within different areas of scholarship are presented and show the difference in approaches to long-term digital preservation, as well as differences in selecting the items and implementing the projects of digital preservation. Institutions and organizations can also develop different understanding of preservation requirements for digital documents and other objects.The final part of the paper is devoted to some general problems pertaining to the longterm digital preservation with the emphasis of the responsibility for the whole process of safe-guarding the cultural and scholarly heritage for the re-use of the posterior generations. It is suggested that the longevity of the libraries in comparison with much shorter life-span of private companies strengthens the claim of memory institutions to playing the central role in the long-term digital preservation.

ANALYTICAL INDICATOR. ANALYSIS OF THE REAL STATE OF DYNAMICS OF MORTALITY OF THE POPULATION OF RUSSIA FROM MALIGNANT TUMORS AND CHANGES IN ITS STRUCTURE

2019 ◽  
Vol 65 (2) ◽  
pp. 205-219 ◽  
Author(s):  
V. Merabishvili
Keyword(s):  
Malignant Tumors ◽  
Specific Weight ◽  
Mortality Rates ◽  
Retirement Age ◽  
Medium Term ◽  
Age Composition ◽  
The Real ◽  
Indicator Analysis ◽  
The Difference ◽  
Real State

The mortality rate is one of the most important criteria for assessing the health of the population. However, it is important to use analytical indicators correctly, especially when evaluating time series. The value of the “gross” mortality is closely linked with a specific weight of persons of elderly and senile ages. All international publications (WHO, IARC, territorial cancer registers) assess the dynamics of morbidity and mortality only by standardized indicators that eliminate the difference in the age composition of the compared population groups. In Russia, from 1960 to 2017, the share of people of retirement age has increased more than 2 times. The structure of mortality from malignant tumors has changed dramatically. The paper presents the dynamics of gross and standardized mortality rates from malignant tumors in Russia and in all administrative territories. Shows the real success of the Oncology service. The medium-term interval forecast until 2025 has been calculated.

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