Survey on relational database watermarking techniques

Digital watermarking has been in multimedia data use over the past years. Recently it has become applicable in relational database system not only to secure copyright ownership but also to ensure data contents integrity. Further, it is used in locating tampered and modified places. However, the watermarking relational database has its own requirements, challenges, attacks and limitations. This paper, surveys recent database watermarking techniques focusing on the importance of watermarking relational database, the difference between watermarking relational database and multimedia objects, the issues in watermarking relational database, type of attacks on watermarked database, classifications, distortion introduced and the embedded information. The comparative study shows that watermarking relational database can be an effective tool for copyright protection, tampered detection, and hacker tracing while maintaining the integrity of data contents. In addition, this study explores the current issues in watermarking relational database as well as the significant differences between watermarking multimedia data and relational database contents. Finally, it provides a classification of database watermarking techniques according to the way of selecting the candidate key attributes and tuples, distortion introduced and decoding methods used

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

Influence of ellipsoid dust Particle Size Distribution on microwave and millimeter wave frequencies

Determining the Particle Size Distribution (PSD) of a solid and liquid particles is of great practical interest. An experimental research was conducted to explore the influence of PSD on propagation properties of electromagnetic wave specifically in microwave and millimeter wave bands. The majority of earlier studies have primarily concentrated on the homogeneous spherical dust particles in mathematical models and equations. Besides, the lack of information on particle shape is one of the main causes for inaccurate calculation and extrapolation. Dust grain is of random shape nevertheless it is analogical to the ellipsoid in the real environment of dust media in collected works. In this paper, emphasis on the shape of particle at Sand and Dust Storm (SDS) phenomena in the microwave and millimeter wave with the actual physical measurement is presented and discussed. Moreover, the examined samples used in the demonstration is the dust grains taken from the Central North of Sudan. The findings of the experiment are essential to many aspects; namely size, shape, number of particles, and A three dimensional relationship is then displayed for these dust particular size with particle diameters (μm), normalized particle amount (diff), and samples code number. Contribution of this study is that specific particle shape distribution with all the parameters could be assist in determine of charge, volume fraction, visibility, and concentration at SDS. This is also useful in many new applications and services such as image radar, remote sensing, and telecommunications links

A systematic literature review on necessity, challenges, applications and attacks of watermarking relational database

Systematic literature review (SLR) is a significant research methodology in software engineering and computer science. One precarious step in applying this methodology is to enterprise and perform appropriate and effective search approach. This is a time-consuming and error-prone step, which needs to be carefully planned and implemented. There is an apparent need for a systematic approach to designing and performing a suitable search strategy for optimally retrieving the target literature from digital libraries. To the best of our knowledge, five intensive review papers [1-5] have been found which are not SLR, instead they are a normal survey or literature review. In contrast to [1-9] this paper followed general guidelines for undertaking SLR in order to illustrate necessity, challenges, applications, and attacks of watermarking relational database. An advanced search has been performed in most relevant digital libraries to obtain potentially relevant articles published until the end of 2014. Forty-six primary studies (PSs) have been identified based on inclusion and exclusion criteria. The analytical study is mainly based on the PSs to achieve the objectives. The results illustrate the importance of digital watermark in protecting the relational database, the differences between watermarking relational database and multimedia objects and the demand to increase the level of attack resilience. In addition, the results indicate that watermarking relational database is an interested area for researchers

A Systematic Literature Review on Necessity, Challenges, Applications and Attacks of Watermarking Relational Database

Systematic literature review (SLR) is a significant research methodology in software engineering and computer science. One precarious step in applying this methodology is to enterprise and perform appropriate and effective search approach. This is a time-consuming and error-prone step, which needs to be carefully planned and implemented. There is an apparent need for a systematic approach to designing and performing a suitable search strategy for optimally retrieving the target literature from digital libraries. To the best of our knowledge, five intensive review papers [1-5] have been found which are not SLR, instead they are a normal survey or literature review. In contrast to [1-9] this paper followed general guidelines for undertaking SLR in order to illustrate necessity, challenges, applications, and attacks of watermarking relational database. An advanced search has been performed in most relevant digital libraries to obtain potentially relevant articles published until the end of 2014. Forty-six primary studies (PSs) have been identified based on inclusion and exclusion criteria. The analytical study is mainly based on the PSs to achieve the objectives. The results illustrate the importance of digital watermark in protecting the relational database, the differences between watermarking relational database and multimedia objects and the demand to increase the level of attack resilience. In addition, the results indicate that watermarking relational database is an interested area for researchers

Robust HEVC video watermarking scheme based on repetition-BCH syndrome code

High efficiency video coding (HEVC) was recently introduced two years ago as the new standard for video coding. This new codec will be the most widely prevalent standard. Because of the industry needs for authentication and copyright protection methodologies the robustness of this standard is required to be developed. This paper presents the first robust digital watermarking method for the HEVC based on Repetition- BCH syndrome code technique without intra-frame distortion drift. The objective of this article is to implement a new technique that can offer high robustness against noise channel errors and increase the error detection rate in the HEVC video sequences transmitted over noisy communication channels. The proposed technique does not significantly affect the video quality, nor does it escalate the bitrate. The results show that the proposed technique offers greater robustness against noise channel while preserving good quality for extracted watermark. The proposed technique significantly contributes to the performance of the error detection and correction. In addition, this technique can recover the watermark when the watermarked frames dropping rate is less than 20%

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic