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Abstract Background and aim Some parallel-group cluster-randomized trials use covariate-constrained rather than simple randomization. This is done to increase the chance of balancing the groups on cluster- and patient-level baseline characteristics. This study assessed how well two covariate-constrained randomization methods balanced baseline characteristics compared with simple randomization. Methods We conducted a mock 3-year cluster-randomized trial, with no active intervention, that started April 1, 2014, and ended March 31, 2017. We included a total of 11,832 patients from 72 hemodialysis centers (clusters) in Ontario, Canada. We randomly allocated the 72 clusters into two groups in a 1:1 ratio on a single date using individual- and cluster-level data available until April 1, 2013. Initially, we generated 1000 allocation schemes using simple randomization. Then, as an alternative, we performed covariate-constrained randomization based on historical data from these centers. In one analysis, we restricted on a set of 11 individual-level prognostic variables; in the other, we restricted on principal components generated using 29 baseline historical variables. We created 300,000 different allocations for the covariate-constrained randomizations, and we restricted our analysis to the 30,000 best allocations based on the smallest sum of the penalized standardized differences. We then randomly sampled 1000 schemes from the 30,000 best allocations. We summarized our results with each randomization approach as the median (25th and 75th percentile) number of balanced baseline characteristics. There were 156 baseline characteristics, and a variable was balanced when the between-group standardized difference was ≤ 10%. Results The three randomization techniques had at least 125 of 156 balanced baseline characteristics in 90% of sampled allocations. The median number of balanced baseline characteristics using simple randomization was 147 (142, 150). The corresponding value for covariate-constrained randomization using 11 prognostic characteristics was 149 (146, 151), while for principal components, the value was 150 (147, 151). Conclusion In this setting with 72 clusters, constraining the randomization using historical information achieved better balance on baseline characteristics compared with simple randomization; however, the magnitude of benefit was modest.

Microarchitectural side-channel vulnerabilities in modern processors are known to be a powerful attack vector that can be utilized to bypass common security boundaries like memory isolation. As shown by recent variants of transient execution attacks related to Spectre and Meltdown, those side channels allow to leak data from the microarchitecture to the observable architectural state. The vast majority of attacks currently build on the cache-timing side channel, since it is easy to exploit and provides a reliable, fine-grained communication channel. Therefore, many proposals for side-channel secure cache architectures have been made. However, caches are not the only source of side-channel leakage in modern processors and mitigating the cache side channel will inevitably lead to attacks exploiting other side channels. In this work, we focus on defeating side-channel attacks based on page translations. It has been shown that the Translation Lookaside Buffer (TLB) can be exploited in a very similar fashion to caches. Since the main caches and the TLB share many features in their architectural design, the question arises whether existing countermeasures against cache-timing attacks can be used to secure the TLB. We analyze state-ofthe-art proposals for side-channel secure cache architectures and investigate their applicability to TLB side channels. We find that those cache countermeasures are not directly applicable to TLBs, and propose TLBcoat, a new side-channel secure TLB architecture. We provide evidence of TLB side-channel leakage on RISC-V-based Linux systems, and demonstrate that TLBcoat prevents this leakage. We implement TLBcoat using the gem5 simulator and evaluate its performance using the PARSEC benchmark suite.

This vignette presents the missing indicator method for handling missing data in covariates. The method unfolds through two activities, guiding students in the practical implementation of the method and comparable alternatives using statistical software. We further evaluate these activities and discuss conditions under which the missing indicator method yields valid results. We conclude that the missing indicator method can be safely used in experimental studies characterized by randomization protocols.

Aim of Study: To prepare for the design of future randomized clinical trials of extracorporeal cardioupulmonary resuscitation (ECPR), we sought to understand physician beliefs regarding the use of ECPR and subsequent management, among physicians who already perform ECPR, as these physicians would be likely to be involved in many planned ECPR trials. Methods: We performed 12 semi-structured interviews of physicians who already perform ECPR across a variety of medical specialties, centers and geographic regions, but all with 10–50+ cases of ECPR experience. We qualitatively analyzed these interview to identify key characteristics of their experience using ECPR, the tensions involved in patient identification, the complications of subsequent management, and their willingness to enroll potential ECPR patients in randomized trials of ECPR. Results: Physicians who routinely perform ECPR have strong beliefs regarding the use of ECPR, and typically have protocols they follow, though they are willing to break these protocols to cannulate young or healthy patients, or patients with immediate pre-hospital CPR and shockable rhythms. We found that physicians lacked equipoise to randomize these types of patients to continued conventional CPR. Future RCTs might be successful in enrolling older patients, younger patients without immediate pre-hospital care/bystander CPR, or patients with obvious comorbidities. Conclusions: RCTs for ECPR will need to avoid targeting patients in whom physicians feel strongly compelled to do ECPR or not do ECPR, instead identifying the middle range of patients in whom the physicians consider ECPR reasonable, but not required or contraindicated.

Background: In critically ill patients requiring extracorporeal membrane oxygenation (ECMO) therapy, early initiation of continuous renal replacement therapy (CRRT) and beta-blockade of catecholamine-induced inotropic effects may improve outcomes.Methods: A 2 × 2 partial factorial randomized controlled trial in eligible ECMO patients without a clear indication or contraindication to either intervention is centrally randomly assigned to (A) early or conventional-indicated CRRT and/or (B) beta-blocker or usual care. The primary outcome is all-cause mortality at 30 days for both arms. A total of 496 participants provides 80% power to determine a 20% risk reduction in mortality at 30 days with 5% type I error.Discussion: This trial will help define the role of early CRRT and beta-blockade in ECMO patients. There have been 89 patients enrolled at 10 hospitals in study A and is ongoing. However, study B was stopped in August 2019 in the absence of any patients being enrolled.Trial Registration: ClinicalTrials.gov NCT03549923 . Registered on 8 June 2018. World Health Organization International Clinical Trials Registry Platform (WHO ICTEP) network. The Ethics Committee of Beijing Anzhen Hospital Approval ID is 2018013. [ABSTRACT FROM AUTHOR]

Researchers conducting small-scale cluster randomized controlled trials (RCTs) during the pilot testing of an intervention often look for evidence of promise to justify an efficacy trial. We developed a method to test for intervention effects that is adaptive (i.e., responsive to data exploration), requires few assumptions, and is statistically valid (i.e., controls the type I error rate), by adapting masked visual analysis techniques to cluster RCTs. We illustrate the creation of masked graphs and their analysis using data from a pilot study in which 15 high school programs were randomly assigned to either business as usual or an intervention developed to promote psychological and academic well-being in 9th grade students in accelerated coursework. We conclude that in small-scale cluster RCTs there can be benefits of testing for effects without a priori specification of a statistical model or test statistic. [ABSTRACT FROM AUTHOR]

Many cluster randomized trials have relatively few numbers of clusters to be randomized. When baseline cluster-level covariates are available prior to randomization, the set of potential allocations can be restricted so as to ensure balance across study arms. This article discusses why and how restrictions can be made, and the ramifications of so doing. The Fisher–Bailey validity is explained, and examples are given regarding the tradeoff between balance and validity. [ABSTRACT FROM AUTHOR]

We show that the so-called motorcycle graph of a planar polygon can be constructed by a randomized incremental algorithm that is simple and experimentally fast. Various test data are given, and a clustering method for speeding up the construction is proposed. [ABSTRACT FROM AUTHOR]

The single‐point and range‐bound changing criterion design have been proposed as single‐case experimental designs. The only form of randomization currently available for these designs is phase change moment randomization. The present article describes two novel randomization procedures for changing criterion designs, the blocked alternating criterion randomization and randomized alternating criterion randomization, and illustrates their use. Appropriate randomization procedures are introduced for situations in which it is desirable to maintain the stepwise nature of the changing criterion design and situations in which the change in the dependent variable can be assumed not to follow the stepwise pattern. The article further discusses contexts in which each of the randomization procedures for the changing criterion design may be useful, and explains how the procedures maintain the researcher's flexibility. [ABSTRACT FROM AUTHOR]

Background: High-quality evidence is often not obtained in the clinical trials of rare diseases because these trials tend to be smaller in size and non-controlled. We investigated the potential factors associated with the need for randomized controlled trials (RCTs) in the clinical data package for new drug applications for rare diseases in Japan. Methods: This study focused on 130 drugs with orphan drug designation approved in Japan between April 2004 and March 2020. Results: Multivariable regression analysis showed that the prevalence (odds ratio [OR] 3.21, 95% confidence interval [CI] 1.18–8.6) and the type of primary endpoint (OR 6.66, 95% CI 2.41–18.37) were associated with the need for RCTs in the clinical data package in Japan. Conclusions: Our findings highlight the importance of adequate understanding of the target disease in new drug development for rare diseases. [ABSTRACT FROM AUTHOR]

The recent innovations in network application and the internet have made data and network security the major role in data communication system development. Cryptography is one of the outstanding and powerful tools for ensuring data and network security. In cryptography, randomization of encrypted data increases the security level as well as the Computational Complexity of cryptographic algorithms involved. This research study provides encryption algorithms that bring confidentiality and integrity based on two algorithms. The encryption algorithms include a well-known RSA algorithm (1024 key length) with an enhanced bit insertion algorithm to enhance the security of RSA against different attacks. The security classical RSA has depreciated irrespective of the size of the key length due to the development in computing technology and hacking system. Due to these lapses, we have tried to improve on the contribution of the paper by enhancing the security of RSA against different attacks and also increasing diffusion degree without increasing the key length. The security analysis of the study was compared with classical RSA of 1024 key length using mathematical evaluation proofs, the experimental results generated were compared with classical RSA of 1024 key length using avalanche effect in (%) and computational complexity as performance evaluation metrics. The results show that RBMRSA is better than classical RSA in terms of security but at the cost of execution time. [ABSTRACT FROM AUTHOR]

The biased randomization and other quality concerns about the Canadian National Breast Screening Studies (CNBSS) were documented and criticized for decades, even by several individuals very close to the research. CNBSS were the outlier studies among several RCTs of the era and yet were given equal weighting and occasionally higher importance than the remainder of the canon of mammography RCTs. These studies have had an ongoing influence on subsequent evidence review, guideline formation, and, ultimately, patient access to screening. This article explores possible reasons for the ongoing inclusion of CNBSS in the body of mammography screening evidence, discusses the lack of expertise in critical healthcare guideline processes, and, ultimately, suggests several actions and reforms. [ABSTRACT FROM AUTHOR]

Over the last two decades, the PageRank problem has received increased interest from the academic community as an efficient tool to estimate web-page importance in information retrieval. Despite numerous developments, the design of efficient optimization algorithms for the PageRank problem is still a challenge. This paper proposes three new algorithms with a linear time complexity for solving the problem over a bounded-degree graph. The idea behind them is to set up the PageRank as a convex minimization problem over a unit simplex, and then solve it using iterative methods with small iteration complexity. Our theoretical results are supported by an extensive empirical justification using real-world and simulated data. [ABSTRACT FROM AUTHOR]

Factorial experiments, wherein two or more factors each at two or more levels are used simultaneously, have profound applications in many fields of agricultural and allied sciences. These experiments allow studying the effect of each individual factor as well as the effects of interactions between factors on the response variable. In order to avoid any kind of bias in the estimation of these effects, it is always advisable that the order of execution of runs in a factorial design is random. However, experimentation under factorial setup may become expensive, time-consuming and difficult due to a large number of changes in factor levels induced by randomization. Adoption of factorial designs with minimum number of changes in the factor levels may prove to be useful in such situations in terms of cost and time. Present paper describes online software developed using client–server architecture for generation of cost effective factorial designs with minimum number of changes in the factor levels viz., webFMC and an R package named FMC. [ABSTRACT FROM AUTHOR]

Combining the concept of randomization with entropic criteria allows solutions to be obtained in the conditions of maximum uncertainty, which is very effective in machine learning and data processing. The application of this approach in data-based entropy-randomized evaluation of functions, randomized hard and soft machine learning, object clustering, and data matrix dimension reduction is demonstrated. Some applications of classification problems, forecasting the electric load of a power system, and randomized clustering of biological objects are considered. [ABSTRACT FROM AUTHOR]

Abstract Background Although oral opioid agonist therapies (OATs), buprenorphine and methadone, are effective first-line treatments, OAT remains largely underutilized due to low retention rates and wide variation across programs. This rapid review therefore sought to summarize the retention rates reported by randomized controlled trials (RCTs) and controlled observational study designs that compared methadone to buprenorphine (or buprenorphine-naloxone). Methods We searched four electronic databases (EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials, CINAHL, up to April 2018) for RCTs and controlled observational studies that compared oral fixed-dose methadone to buprenorphine versus methadone (or buprenorphine-naloxone). Data were extracted separately for two different definitions of retention in treatment: (1) length of time retained in the study and (2) presence on the final day of a study. Separate random effects meta-analyses were performed for RCTs and controlled observational studies. Data from controlled observational studies where retention was measured as the length of time retained in the study were not amenable to meta-analysis. Results Among 7603 studies reviewed, 10 RCTs and 3 observational studies met inclusion criteria (n = 5065) and compared fixed-dose oral buprenorphine with methadone. Across studies, the average retention rate was highly variable (RCTs: buprenorphine 20.0–82.5% and methadone 30.7–83.8%; observational studies: buprenorphine 20.2–78.3% and methadone 48.3–74.8%). For time period retained in the study, we observed no significant difference in treatment retention for buprenorphine versus methadone in RCTs (standardized mean difference [SMD] = − 0.07; 95% CI − 0.35–0.21, p = 0.63; quality of evidence: low). For presence on the final study day, we observed no significant difference between buprenorphine and methadone treatment retention in RCTs (risk ratio [RR] = 0.89; 95% CI 0.73–1.08, p = 0.24; quality of evidence: low) and controlled observational studies (RR = 0.75; 95% CI 0.36–1.58, p = 0.45). Conclusion Meta-analysis of existing RCTs suggests retention in oral fixed-dose opioid agonist therapy with methadone appears to be generally equal to buprenorphine (or buprenorphine-naloxone), with wide variation across studies. Similarly, a meta-analysis of three controlled observational studies indicated no difference in treatment retention although there was significant heterogeneity among the included studies. The length of follow-up did not appear to affect the retention rate. Systematic review registration PROSPERO CRD42018104452 .

Abstract Background Randomized controlled trials (RCT) are considered the ideal design for evaluating the efficacy of interventions. However, conducting a successful RCT has technological and logistical challenges. Defects in randomization processes (e.g., allocation sequence concealment) and flawed masking could bias an RCT’s findings. Moreover, investigators need to address other logistics common to all study designs, such as study invitations, eligibility screening, consenting procedure, and data confidentiality protocols. Research Electronic Data Capture (REDCap) is a secure, browser-based web application widely used by researchers for survey data collection. REDCap offers unique features that can be used to conduct rigorous RCTs. Methods In September and November 2020, we conducted a parallel group RCT among Indiana University Bloomington (IUB) undergraduate students to understand if receiving the results of a SARS-CoV-2 antibody test changed the students’ self-reported protective behavior against coronavirus disease 2019 (COVID-19). In the current report, we discuss how we used REDCap to conduct the different components of this RCT. We further share our REDCap project XML file and instructional videos that investigators can use when designing and conducting their RCTs. Results We reported on the different features that REDCap offers to complete various parts of a large RCT, including sending study invitations and recruitment, eligibility screening, consenting procedures, lab visit appointment and reminders, data collection and confidentiality, randomization, blinding of treatment arm assignment, returning test results, and follow-up surveys. Conclusions REDCap offers powerful tools for longitudinal data collection and conduct of rigorous and successful RCTs. Investigators can make use of this electronic data capturing system to successfully complete their RCTs. Trial registration The RCT was prospectively (before completing data collection) registered at ClinicalTrials.gov; registration number: NCT04620798 , date of registration: November 9, 2020.

Introduction: Randomized controlled clinical trial studies are the most valuable types of studies that their proper design and accurate reporting are of particular importance in medical science. This study was performed with aim to critically evaluate the randomized controlled clinical trial studies in the Iranian Journal of Obstetrics, Gynecology and Infertility. Methods: In this cross-sectional analytic study, the clinical trial articles of the Iranian Journal of Obstetrics, Gynecology and Infertility between 2009 and 2019 were collected and scored based on the latest edition of the Consort Checklist (2010) by three biostatisticians that their training's adequacy was confirmed by measuring the kappa agreement coefficient. The articles were scored, and based on the scores, they were classified into five categories: very poor to excellent. Data were analyzed by SPSS software (version 25) and descriptive statistics. Results: Out of a total of 1318 articles published during 11 years, 325 were clinical trials, among them only 6 articles (1.85%) were rated as excellent. The lowest and highest scores among the reviewed articles were 14 and 28 (maximum score was 37). The mean and standard deviation of the scores obtained in all articles was calculated as 19.05± 0.34. However, less attention was paid to the two main issues of randomization and blindness in the clinical trials. Conclusion: Due to the importance of clinical trial studies, it is necessary to pay attention to the articles' quality based on the consort checklist. It is also suggested that authors of such articles pay more attention to the two essential foundations of clinical studies, randomization and blindness, to increase the generalization of the results.

A new method was proposed to estimate ecosystem naturalness. Three species-plot (S Χ A) datasets were used. Those data sets belong to Sultan mountain sub-district (BS) (60 Χ 96) Dedegül mountain sub-district (BD) (89 Χ 119) and, Beyşehir Watershed (B) (98 Χ 215) consisting of both of the sub-districts. Firstly, chi square test (χ^2 ) was applied to define the statistical goodness of fit between the first digit observed probabilities (〖d_1 p〗_o ) and the theoretical probabilities of Benford’s Law (d_1 p_e ). It was found that χ^2 (e_BS )=16.579 and χ^2 (e_BD )=2.406.Secondly, to find the fittest theoretical probabilities for BS and BD, generalized Benford’s Law (GB(d;γ)) was applied. Minimal χ^2 values were obtained at γ=0.65 and γ=0.07 for BS and BD respectively (χ^2 (e_BD^γ )=4.992, χ^2 (e_BD^γ )=2.209). As expected, χ^2 values of the sub-districts decreased by generalized Benford’s Law. The most dramatic χ^2 decrease occurred in BS. The number of sample plots of the sub-districts are different. Two random iterative processes happened 10000 times were therefore performed considering the number of sample plots of the sub-districts in B dataset. As a result 10000 χ^2 values were obtained for each sub-district. Average values of those χ^2 values were then used ((_ ^k)(χ^2 ) ̅ (E_BS^γ )=6.747 and (_ ^k)(χ^2 ) ̅ (E_BD^γ )=6.176) to calculate calibration coefficients of each sub-district. Naturalness values of BS and BD were found to be 4.992 and 2.414 respectively due to calibration coefficients of BS= ((_ ^k)(χ^2 ) ̅ (E_max^γ ))⁄((_ ^k)(χ^2 ) ̅ (E_BS^γ ) )=1 and BD=((_ ^k)(χ^2 ) ̅ (E_max^γ ))⁄((_ ^k)(χ^2 ) ̅ (E_BD^γ ) )=1.093. Since the perfect naturalness value is theoretically equal to 0, the obtained results indicate that BD ecosystems are more natural than BS ecosystems.

The effectiveness of combining SQL statement parsing with randomization to defend against SQL injection attack (SQLIA) was based on the fact that attackers did not know about the current method of randomization adopted by system.Therefore, once attackers had mastered the current method of randomization who can launch effective SQLIA.In order to solve this problem, a SQL injection runtime prevention system based on multi-variant execution was designed, the multi-variant apply randomization methods from any other, so that illegal SQL statements could not be parsed successfully by all variants.Even if attackers had mastered the method of randomization, illegal SQL statements could only be parsed successfully by a certain variant at most, meanwhile the parsing results of multiple variants were voted to find the abnormality in time and block attack path.The prototype system SQLMVED is implemented for Web services and experiments show that the prototype can effectively defeat SQLIA.

Understanding the abstract principles of statistical experimental design can challenge undergraduate students, especially when learned in a lecture setting. This article presents a concrete and easily replicated example of experimental design principles in action through a hands-on learning activity for students enrolled in an experimental design course. The activity, conducted during five 50-min classes, requires the students to work as a team to design and execute a simple and safe factorial experiment and collect and analyze the data. During three in-class design meetings, the students design and plan all aspects of the experiment, including choosing the response variable and factors, making a list of needed supplies, creating a randomized run schedule with the MINITAB DOE utility, and writing a statistical analysis plan. A feasibility study is conducted in the fourth class. During the fifth and last class, the students conduct the experiment. Each student writes a lab report including all background research, methods, analyses, and conclusions, as well as a reflection on the learning experience. Students’ reflections indicate the active-learning experience was enjoyable and boosted course engagement and perceived conceptual understanding.

A result from a standard linear model course is that the variance of the ordinary least squares (OLS) coefficient of a variable will never decrease when including additional covariates into the regression. The variance inflation factor (VIF) measures the increase of the variance. Another result from a standard linear model or experimental design course is that including additional covariates in a linear model of the outcome on the treatment indicator will never increase the variance of the OLS coefficient of the treatment at least asymptotically. This technique is called the analysis of covariance (ANCOVA), which is often used to improve the efficiency of treatment effect estimation. So we have two paradoxical results: adding covariates never decreases the variance in the first result but never increases the variance in the second result. In fact, these two results are derived under different assumptions. More precisely, the VIF result conditions on the treatment indicators but the ANCOVA result averages over them. Comparing the estimators with and without adjusting for additional covariates in a completely randomized experiment, I show that the former has smaller variance averaging over the treatment indicators, and the latter has smaller variance at the cost of a larger bias conditioning on the treatment indicators. Therefore, there is no real paradox.

Using the randomization approach, introduced by A. Tempelman in Randomized multivariate central limit theorems for ergodic homogeneous random fields, Stochastic Processes and their Applications. 143 (2022), 89–105, we prove: (a) a randomized version of the invariance principle (the functional CLT); (b) a version the Glivenko–Cantelli theorem; (c) a randomized theorem about convergence of empirical processes to the Brownian bridge. We also weaken the moment condition in the randomized CLTs, proved in the mentioned article. The main point of our work is that most of our theorems are valid for all ergodic homogeneous random fields on Z m and R m , m ≥ 1. [ABSTRACT FROM AUTHOR]

Physiological health effects (vibration perception thresholds and infrared skin temperature) of single-impact exposures and vibration exposures have been evaluated. In this experiment, a total of 52 healthy male participants were randomly exposed to single shocks of different frequencies (1 s−1, 4 s−1, and 20 s−1) and to random signal vibration exposures (4 × 5 min exposure duration). We observed frequency-dependent and eventually dose-dependent physiological effects. No exposure parameter systematically correlated to any of the examined physiological outcomes. This could hint at different pathways for physiological effects.

Randomization-based inference is a useful alternative to traditional population model-based methods. In trials with missing data, multiple imputation is often used. We describe how to construct a randomization test in clinical trials where multiple imputation is used for handling missing data. We illustrate the proposed methodology using Fisher's combining function applied to individual scores in two post-traumatic stress disorder trials. [ABSTRACT FROM AUTHOR]

Background & Objective: This study aimed to assess the clinical effectiveness of Hydroxychloroquine Sulfate (200 mg orally 8 hourlies thrice a day for 5 days), oseltamivir (75 mg orally twice a day for 5 days), and Azithromycin (500 mg orally daily on day 1, followed by 250 mg orally twice a day on days 2-5) alone and in combination (in seven groups). Methods & Analysis: An adaptive design is deployed, set within a comprehensive cohort study, to permit flexibility in fast-changing clinical and public health scenario. Primary outcomes include turning the test negative for coronavirus nucliec acid and in bringing about clinical improvement on day 7 of follow-up on a seven-point ordinal scale. The randomized study will recruit participants of either gender above 18 years of age who will test positive for SARS-CoV-2 on Quantitative Reverse Transcription Polymerase Chain Reaction (PCR). Pregnant or lactating females, and those with severe respiratory distress, or with serious comorbidities will be excluded. Randomization will be done maintaining concealment of allocation sequence using a computer-generated random number list. The sample size will be subjected to periodic reviews by National Data Safety and Monitoring Board. Ethics and Dissemination: The trial is approved by the National Bioethics Committee (No.4-87/NBC-471-COVID-19-05/20/) and institutional Ethical Review Committee. This clinical trial conducted under Good Clinical Practice is expected to inform patients clinical guidelines for the use of these drugs in newly diagnosed with SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Data Mining is a technical process which involves the conversion of a raw data into a useful data. There is generally certain sequence of steps involved in obtaining a useful information. One of the important usages of the data mining technique is to identify certain useful patterns that can be utilized to solve certain real-world problems. Utility mining is a domain of data mining which is mainly used to identify the high utility based item sets which are considered based on certain parameters like quantity, cost, profit, affordability and certain preferences of the users. Utility mining impacts various domains like online commerce industry, medical domains, biomedical applications, finance, marketing and its allied domains. In this survey we discuss about the general structure in the pattern mining and various algorithms being applied to the privacy preservation like the randomization, k-anonymity and certain other hybrid techniques that is applied to the health care domain for preserving the privacy even though when the data is stored in the cloud and we consider various real-world problems and discuss about the open challenges in this research domain. [ABSTRACT FROM AUTHOR]

We study the relationship between the competitive ratio and the tail distribution of randomized online problems. To this end, we identify a broad class of online problems for which the existence of a randomized online algorithm with constant expected competitive ratio r implies the existence of a randomized online algorithm that has a competitive ratio of (1 + ε) r with high probability, measured with respect to the optimal profit or cost, respectively. The class of problems includes some of the well-studied online problems such as paging, k-server, and metrical task systems on finite metric spaces. [ABSTRACT FROM AUTHOR]

The use of random MAC addresses is considered as an important tool to improve a user's privacy on a Wi-Fi network. Although this technique was proposed since 2014, its implementation was not effective immediately but had an uneven evolution over the following years. This paper studies the evolution of random MAC addresses based on the analysis of data collected in public Wi-Fi networks located in different areas of Latin American countries from 2016 to 2021. Statistical analysis is performed using the analysis of variance technique (ANOVA) that tests whether there are significant differences in the rate of MAC randomization over different periods of time and thereby identified an uneven evolution of the implementation of MAC address randomization measures in mobile devices with different operating systems, and also the massification of these measures from 2019. The development of the massification of randomized MAC addresses and the impact of the existence of centralized and widely controlled operating systems, such as iOS, is evident. [ABSTRACT FROM AUTHOR]

We study the foundations for the development of optimal randomization in mixed strategy games. We consider a population of children and adolescents (7 to 16 years old) and study in the laboratory their behavior in a nonzero sum, hide‐and‐seek game with a unique interior mixed strategy equilibrium where each location has a known but different value. The vast majority of participants favor the high‐value location not only as seekers (as predicted by theory) but also as hiders (in contradiction with theory). The behavior is extremely similar across all ages, and also similar to that of the college students control adult group. We also study the use of cheap talk (potentially deceptive) messages in this game. Hiders are excessively truthful in the messages they send while seekers have a slight tendency to (correctly) believe hiders. In general, however, messages have a small impact on outcomes. The results point to a powerful (erroneous) heuristic thinking in two‐person randomization settings that does not get corrected, even partially, with age. [ABSTRACT FROM AUTHOR]

AIMS: The primary purpose of the present trial was to evaluate the effect of low-frequency (30Hz) vibrations on the rate of canine retraction. SETTING AND DESIGN: Single-center, split mouth prospective randomized controlled clinical trial METHODS AND MATERIAL: 100 screened subjects (aged18--25 years) were selected; out of which 30 subjects having Class I bimaxillary protrusion or Class II div 1 malocclusion, requiring upper 1st premolar therapeutic extractions, were selected for the study. A split-mouth study design was prepared for the maxillary arch of each selected individual and was randomly allocated into vibration and nonvibration side (control) groups. A customized vibratory device was fabricated for each subject to deliver low-frequency vibrations (30 Hz). Scanned 3D models were prepared sequentially to assess the amount of tooth movement from baseline (T0),(T1), (T2), (T3), and (T4)-4th month of canine retraction. STATISTICAL ANALYSIS USED: Independent "t" test. RESULTS: There was no statistically significant differencein the rate of individual canine retraction among the experimental and control groups when the intergroup comparison was done using independent "t" test at T1-T0, (P = 0.954), T2-T1 (P = 0.244), T3-T2 (P = 0.357), and T4-T3 (P = 0.189). CONCLUSION: The low-frequency vibratory stimulation of 30 Hz using a customized vibratory device did not significantly accelerate the rate of orthodontic tooth movement. [ABSTRACT FROM AUTHOR]

Objectives: The use of intrauterine devices (IUDs) and contraceptive implants in South Africa is low with limited data on patterns of use and reasons for discontinuation. We describe contraceptive preferences and reasons for discontinuation among women enrolled in the Evidence for Contraceptive Options and HIV Outcomes (ECHO) Trial from one trial site.Study Design: ECHO, conducted between 2015 and 2018, enrolled and randomized sexually active women, aged 16 to 35, and desiring contraception, to intramuscular depot medroxyprogesterone acetate (DMPA-IM), a copper intrauterine device (copper-IUD) or a levonorgestrel (LNG) implant; follow-up was 12 to 18 months. We interviewed 829 women at the Durban, South Africa trial site at ECHO Trial exit to ascertain contraceptive preferences at randomization. Reasons for randomized contraceptive discontinuation were collected at ECHO Trial exit and 6 months later. Data were analyzed descriptively.Results: At the final ECHO Trial visit, among women using their randomized contraceptive method (n = 757), 21% discontinued DMPA-IM, 20% discontinued LNG implant and 22% discontinued the copper-IUD. About a quarter from each group discontinued due to problems with bleeding. Among women continuing their randomized contraceptive at trial exit (n = 597), 25% discontinued DMPA-IM within 6 months of exiting the study, 8% discontinued LNG implant and 4% discontinued copper-IUD. A third of women reported wanting to be assigned DMPA-IM at randomization, 20% wanted the LNG implant and 18% the copper-IUD.Conclusions: Despite some women having preferences about which contraceptive they might be randomized to, discontinuation rates for all three methods at ECHO Trial exit and 6-month post-trial follow-up were low.Implications: Despite limited prior use of IUDs and implants among women enrolled in this study, and a desire by some women to not receive these methods at randomization, discontinuation rates remained low. The provision of quality contraceptive counselling and support may increase uptake and continued use of implants and IUDs. [ABSTRACT FROM AUTHOR]

The objective of study designed to concur whether micronutrient concentration change reduces the high burden of growth defect of young children age 6 to 59 after nutrition behavior exertions end in Central highland Ethiopia. We used a cluster parallel, -non-inferiority randomized control trial. "Kebeles" [lower administrations] selected from central highland districts randomly assigned to either the intervention or the control cluster. At the baseline survey, 1012 children aged 6 -59 months and paired mothers were selected from randomly assigned kebeles using a systematic sampling method. The intervention cluster was appointed to exploit nutrition behavior intervention through 15 months. The baseline and end-line data contained median urine iodine, hemoglobin, anthropometry, and other variables analyzed using independent t-test and Generalized Estimate Equation (GEE) using SPSS version 21 software. At the end-line, about 715 study participants completed the nutrition Behavior Change Communication (BCC) intervention. A very high (42.1%) prevalent growth defect observed at baseline and reduced to high level (28.67%) at the end-line. Baseline iodine concentration by 0.69 cm (B=0.69, P<0.05) and end-line by 0.271 cm (B=0.271, P <0.05) somewhat increased average end-line height compared to iron concentration. The difference of height(Ht) baseline -- end-line between intervention and control group was 0.51 cm. Being in the intervention cluster increased Ht by 10.8 cm (beta [β] = 10.8, standard error [SE] = 1.023) than other predictors of growth of children. This community-based study implied the need for efforts to improve the linear growth of children at an early age through inspiring nutrition behavior. [ABSTRACT FROM AUTHOR]

High‐dimensional biomarkers such as genomics are increasingly being measured in randomized clinical trials. Consequently, there is a growing interest in developing methods that improve the power to detect biomarker–treatment interactions. We adapt recently proposed two‐stage interaction detecting procedures in the setting of randomized clinical trials. We also propose a new stage 1 multivariate screening strategy using ridge regression to account for correlations among biomarkers. For this multivariate screening, we prove the asymptotic between‐stage independence, required for familywise error rate control, under biomarker–treatment independence. Simulation results show that in various scenarios, the ridge regression screening procedure can provide substantially greater power than the traditional one‐biomarker‐at‐a‐time screening procedure in highly correlated data. We also exemplify our approach in two real clinical trial data applications. [ABSTRACT FROM AUTHOR]

Two randomized trials were conducted in Canada in the 1980s to test the efficacy of breast cancer screening. Neither of the trials demonstrated benefit. Concerns were raised regarding serious errors in trial design and conduct. Here we describe the conditions that could allow subversion of randomization to occur and the inclusion of many symptomatic women in a screening trial. We examine anomalies in data where the balance would be expected between trial arms. "Open book" randomization and performance of clinical breast examination on all women before allocation to a trial arm allowed women with palpable findings to be mis-randomized into the mammography arm. Multiple indicators raising suspicion of subversion are present including a large excess in poor-prognosis cancers in the mammography trial arm at prevalence screen. Personnel described shifting of women from the control group into the mammography group. There is compelling evidence of subversion of randomization in Canadian National Breast Screening Study. Mis-randomization of even a few women with advanced breast cancer could markedly affect measured screening efficacy. The Canadian National Breast Screening Study trials should not influence breast screening policies. [ABSTRACT FROM AUTHOR]

In this short note, we describe the solution of the problem of Littlewood-type randomization in the context of generalized mixed norm spaces, motivated by the recent result of Cheng, Fang and Liu [3]. [ABSTRACT FROM AUTHOR]