Relational nullable types with Boolean unification

We present a simple, practical, and expressive relational nullable type system. A relational nullable type system captures whether an expression may evaluate to null based on its type, but also based on the type of other related expressions. The type system extends the Hindley-Milner type system with Boolean constraints, supports parametric polymorphism, and preserves principal types modulo Boolean equivalence. We show how to support full Hindley-Milner style type inference with an extension of Algorithm W. We conduct a preliminary study of open source projects showing that there is a need for relational nullable type systems across a wide range of programming languages. The most important findings from the study are: (i) programmers use programming patterns where the nullability of one expression depends on the nullability of other related expressions, (ii) such invariants are commonly enforced with run-time exceptions, and (iii) reasoning about these programming patterns requires not only knowledge of when an expression may evaluate to null, but also when it may evaluate to a non-null value. We incorporate these observations in the design of the proposed relational nullable type system.

Bayesian Estimation of the Variation in Strength and Aerobic Physical Performances in Young Eumenorrheic Female College Students during a Menstrual Cycle

Background: The purpose of the present investigation was to examine changes in strength and aerobic physical performances in young eumenorrheic female college students during the menstruation phase and different testing occasions within a menstrual cycle. Methods: A repeated measure experimental design used to investigate the variation in physical performance from different testing occasions compared to the menstruation phase. Twelve eumenorrhea female college students volunteered to participate in this study. The participants were 19.8 ± 0.8 (±SD) years old, with the body mass of 61.4 ± 11.6 kg, the height of 162.6 ± 5.1 cm, and BMI of 23.2 ± 3.8. All participants reported regular monthly menstrual cycles of 26–33 days, none of whom reported taking oral contraceptives in their entire life. None of the participants was an athlete, and their level of activity was limited to physical education classes and recreational activities. The menstrual cycles during the two cycles before testing had to be between 26 and 35 days to participate in this study. Second, there had to be no current or ongoing neuromuscular diseases or musculoskeletal injuries. Third, no one should be taking any dietary or performance-enhancing supplements that could have affected testing results during this study. The participants tested on one-repetition maximum (1RM) bench press, 1RM leg press, push-up to failure, leg press with 60% of 1RM to failure, and running 1600 m time trial. The participants were tested on four occasions based on the classical model of the menstrual cycle (i.e., 28 days; early follicular phase (menstruation phase) on day 2 (T1), late follicular phase on day 8 (T2), ovulation phase on day 14 (T3), and mid-luteal phase on day 21 (T4)). Data were analyzed using the Bayesian hierarchical model (Bayesian Estimation) with Markov Chain Monte Carlo simulation using the decision-theoretic properties of the high-density interval (HDI) + ROPE decision rule. Results: The Bayesian estimated difference from the four testing occasions neither showed that the most credible parameter values (95% HDI) were sufficiently away from the null value nor showed that the most credible parameter values are close to the null value (Rope odds ratio among all tests were spread in 12.7% < 0 < 87.3% with an effect size ranging between d = −0.01 and 0.44). Hence, no decision can be made as to whether strength and aerobic physical performances change during the menstruation phase compared to the other testing occasions within a menstrual cycle. Conclusions: It was noticed that different studies concluded different results, which make the research in menstrual cycle difficult. However, the results from this study and published studies suggest that future research should investigate and profile motivation and autonomic nervous system activity during the menstruation phase and examine the interaction effect of the three on performance compared to other testing occasions within a menstrual cycle.

Research on data fusion method of multi-source complex system

Multi source fusion of data collected by various sensors to realize accurate perception is the key basic technology of the Internet of things. At present, there are many problems in the fusion of various kinds of data collected by sensors, such as more noise and more null values. In this paper, the fuzzy neural network algorithm is proposed to establish the model, combined with the Delphi method and the null value estimation method based on the prediction value to construct the data fusion system. This method has rich application scenarios in the construction of IOT system in the field of power and energy.

Cipher-Policy Attribute-Based Encryption on Cloud Computing

Cloud computing has drawn expanding interests from both scholastic and industry in the recent years because of its productiveness and low-cost management. Since it offers different types of assistance in an open organization, it is critical for users to utilize secure information for stockpiling and sharing data to guarantee information classification and data users protection. To safely Protect information, the most broadly utilized technique is encryption. The dual-access control, with regards to cloud-based storage, is a control system over both the data owner and the user who can upload and download files without loss of safety, data[1] and effectiveness. The credulous arrangement is that the user can download the whole database[2]. The framework planned in this paper is when the A user logs in with his credentials and after successful acceptance from the two different administrators, the user will be able to download the file present over the cloud. When a malicious user requests, the administrators can find it because it will generate a null value and they can block the user from downloading the files.

SILR: A New Exact Test for Demonstrating That an Effect Exists in Binary Trials

Suppose N experimental participants each undergo t binary trials, and you want to show that at least some of the participants have higher success rates than would be expected if the true success rate for all participants on all trials were the same known value pnull. Under broad circumstances, a new test called SILR has substantially higher power than six other tests that might be used for this purpose. In one example, SILR yielded a significance level of 0.0032 while the other six tests all yielded values above 0.05. In one power analysis, SILR’s power exceeded that of the standard binomial test, applied to the results of all trials for all participants, even when the sample size for SILR was less than 30% that for the binomial.We provide a free R program for SILR. It can also find confidence limits on the number of experimental participants whose true hit rate exceeds the null value, and on the highest and lowest true hit rates of any participants. SILR does not show conclusively that any particular participant’s true hit rate differs significantly from the null rate. If such tests are desired, that can be done with Bonferroni-corrected binomial tests on individual participants. But SILR often has much higher power than these tests.

Resolving Interoperability Issues of Date with Null Value and Collection of Complex Data Types by Using JADE-WSIG Framework

In today’s world, the internet and distributed computing make things so convenient that web services can be easily built and fetch from any platform. Web services are loosely coupled, interoperable, and heterogeneous hence they help to connect web applications of different languages. Interoperability is the major factor while transferring web services from one platform to another platform.WS-I basic profile 1.0/1.1 organization provides guidelines to achieve interoperability of web services at a basic level but still, issues arise at a complex level. In this paper, we have discussed and shown the result of two interoperability issues i.e. Date with Null value and Collection of Complex data types of web services using JAVA and.NET environment. In the first issue.NET treat NULL as a value type and JAVA treats NULL as reference type in date-time data type. So, whenever a JAVA client fetches a web service built in.NET it will show a parsable error. In the second issue, a web service data structure contains elements of any type. Whenever, a web service built with the ‘ArrayOfAnyType’ data structure, it can be easily mapped to a.NET client but not to JAVA client. Hence, a data type mismatch issue arises here. To resolve these inter-platform issues, we have used JADE-WSIG as middleware between web services and agent-technology.

Environmental Risk Factors and Congenital Heart Disease: An Umbrella Review of 165 Systematic Reviews and Meta-Analyses With More Than 120 Million Participants

Background: The etiology of congenital heart disease (CHD) has been extensively studied in the past decades. Therefore, it is critical to clarify clear hierarchies of evidence between types of environmental factors and CHD.Methods: Electronic searches in PubMed, Embase, Web of Science, Cochrane database were conducted from inception to April 20, 2020 for meta-analyses investigating the aforementioned topic.Results: Overall, 41 studies including a total of 165 meta-analyses of different environmental factors and CHD were examined, covering a wide range of risk factors. The summary random effects estimates were significant at P &lt; 0.05 in 63 meta-analyses (38%), and 15 associations (9%) were significant at P &lt; 10−6. Of these meta-analyses, eventually one risk factor (severe obesity; relative risk: 1.38, 95% confidence interval: 1.30–1.47) had significant summary associations at P &lt; 10−6, included more than 1,000 cases, had 95% prediction intervals excluding the null value, and were not suggestive of large heterogeneity (I2 &lt; 50%), small-study effects (P-value for Egger's test &gt; 0.10), or excess significance (P &gt; 0.10). Eight associations (5%) (including maternal lithium exposure, maternal obesity, maternal alcohol consumption, and maternal fever) had results that were significant at P &lt; 10−6, included more than 1,000 cases, and had 95% prediction intervals excluding the null value (highly suggestive).Conclusion: This umbrella review shows that many environmental factors have substantial evidence in relation to the risk of developing CHD. More and better-designed studies are needed to establish robust evidence between environmental factors and CHD.Systematic Review Registration: [PROSPERO], identifier [CRD42020193381].

Drying a mindsponge: transcending belief

As an extreme example, one may accept a null value into one's belief system.