Testing hypotheses using unweighted means

Testing main effects and interaction effects in factorial designs are basic content in statistics textbooks and widely used in various fields. In balanced designs there is general agreement on the appropriate main effect and interaction sums of squares and these are typically displayed in an analysis of variance (ANOVA). A number of methods for analyzing unbalanced designs have been developed, but in general they do not lead to unique results. For example, in SAS one can get three different main effect sums of squares in an unbalanced design. I, If these results are viewed from the theory of the general linear model, then it is typically the case that the different sums of squares all lead to F-tests, but they are testing different linear hypotheses. In particular, if one clearly specifies the linear hypothesis being tested, then linear model theory leads to one unique deviation sum of squares. One exception to this statement is an ANOVA, called an unweighted means ANOVA (UANOVA) introduced by Yates (1934). The deviation sum of squares in a UNANOVA typically does not lead to an F-test and hence does not reduce to a usual deviation sum of squares for some linear hypothesis. The UANOVA tests have been suggested by several writers as an alternative to the usual tests. Almost all of these results are limited to the one-way model or a two-way model with interaction, and hence the UANOVA procedure is not available for a general linear model. This thesis generalizes the UANOVA test prescribed in the two-way model with interaction to a general linear model. In addition, the properties of the test are investigated. It is found, similar to the usual test, that computation of the UANOVA test statistic does not depend on how the linear hypothesis is formulated. It is also shown that the numerator of the UANOVA test is like a linear combination of independent chi-squared random variables as opposed to a single chi-squared random variable in the usual test. In addition we show how the Imhof (1961) paper can be used to determine critical values, p-values and power for the UANOVA test. Comparisons with the usual test are also included. It is found that neither test is more powerful than the other. Even so, for most circumstances our general recommendation is that the usual test is probably superior to the UANOVA test

Analysis of Platforms and Functions of Mobile-Based Personal Health Record Systems

ObjectivesLittle is known about the platforms and functionalities of mobile-based personal health record (PHR) applications. The objective of this study was to investigate these two features of PHR systems.MethodsThe unit of analysis was general hospitals with more than 100 beds. This study was based on a PHR survey conducted from May 1 to June 30, 2020 and the National Health Insurance administrative data as of March 31, 2020. The study considered the platform, Android and iPhone operation system (iOS), and types of functionalities of PHR systems. Among the 316 target hospitals, 103 hospitals had adopted PHR systems. A logistic regression analysis was used.ResultsThis study found that 103 hospitals had adopted mobile-based PHR systems for their patients. Sixty-four hospitals (62.1%) were adopting both Android and iOS, but 36 (35.0%) and 3 (2.9%) hospitals were adopting Android only or iOS only, respectively. The PHR systems of hospitals adopting both platforms were more likely to have functions for viewing prescriptions, clinical diagnostic test results, and upcoming appointment status compared to those adopting a single platform (p \u3c 0.001). The number of beds (odds ratio [OR] = 1.004; confidence interval [CI], 1.001–1.007; p = 0.0029) and the number of computed tomography systems (CTs) per 100 beds (OR = 6.350; CI, 1.006–40.084; p = 0.0493) were significantly associated with the adoption of both platforms.ConclusionsMore than 60% of hospitals had adopted both Android and iOS platforms for their patients in Korea. Hospitals adopting both platforms had additional functionalities and significant association with the number of beds and CTs

Silicon-compatible high-hole-mobility transistor with an undoped germanium channel for low-power application

In this work, Ge-based high-hole-mobility transistor with Si compatibility is designed, and its performance is evaluated. A 2-dimensional hole gas is effectively constructed by a AlGaAs/Ge/Si heterojunction with a sufficiently large valence band offset. Moreover, an intrinsic Ge channel is exploited so that high hole mobility is preserved without dopant scattering. Effects of design parameters such as gate length, Ge channel thickness, and aluminum fraction in the barrier material on device characteristics are thoroughly investigated through device simulations. A high on-current above 30 ??A/??m along with a low subthreshold swing was obtained from an optimized planar device for low-power applications.open0

Coulomb oscillations based on band-to-band tunneling in a degenerately doped silicon metal-oxide-semiconductor field-effect transistor

The Coulomb oscillations based on band-to-band tunneling through a valence band in silicon metal-oxide-semiconductor field-effect-transistors were discussed. It was found that the formation of tunnel barries and a quantum dot in a single-electron transistor structure originated from two p+ - p+ tunnel junctions and a p+ -doped channel with mesoscopic dimension, respectively. At liquid nitrogen temperature, the Coulomb-blockade oscillations with multiple peaks were also observed. Analysis shows that the single-electron charging effect based on band-to-band tunneling was confirmed using the electrical and thermal characterization of the quantum dots.open2