Groups in Which Commutativity Is a Transitive Relation

AbstractWe investigate the structure of groups in which commutativity is a transitive relation on non-identity elements (CT-groups). A detailed study of locally finite, polycyclic, and torsion-free solvableCT-groups is carried out. Other topics include fixed-point-free groups of automorphisms of abelian torsion groups and their cohomology groups

Effect of acupressure on postpartum low back pain, salivary cortisol, physical limitations, and depression: a randomized controlled pilot study

Objective: To investigate the effect of acupressure on postpartum low back pain (LBP), salivary cortisol, physical limitations, and postpartum depression. Methods: Participants were 70 postpartum women who were randomly assigned to either an intervention (n = 35) or a control (n = 35) group. The intervention group received 10 acupressure sessions (1 session per day, 5 d per week). The control group received 10 sham acupressure sessions. Outcomes were assessed using a visual analogue scale (LBP intensity), salivary cortisol values (LBP biomarker), and Chinese versions of the Roland-Morris Disability Questionnaire (daily activity limitations), Oswestry Disability Index (physical activity limitations), and the Edinburgh Postnatal Depression Scale (postpartum depression). Results: Participants in the intervention group had significantly lower levels of LBP intensity, daily activity limitations, physical activity limitations, and postpartum depression than those in the control group. There was no significant between-group difference in salivary cortisol. Conclusion: Acupressure may reduce postpartum LBP intensity and limitations in daily and physical activity, and alleviate postpartum depressive symptoms. Acupressure should be offered in postpartum care settings as an alternative treatment for postpartum women with LBP

IT/IS as the Secret Scroll of Kung Fu: A Functionalist Explanation of A Technical Structure for Information Systems Design

A company encounters many negative social consequences and persistent problems when it adopts a specific technical structure for an information system (IS). But, why do they continue using it, not wishing to abandon it? This paper uses the functionalist explanation to interpret the contradictory phenomenon through a real case which expects to enhance work efficiency and improve business processes by developing a new IS. During IS development and implementation, the rivalry between IT personnel and users occurs while they closely cooperate. Nevertheless, a shared belief that “IT/IS as the Secret Scroll of Kung Fu”, which implies IT/IS with a magic power, has been unexpectedly developed between them. In other words, both divisions believe that IT/IS would be able to solve all unintended problems to be encountered. Therefore, they still kept cooperating to develop IS, and did not admit the failure of IS

Comparative analysis of port efficiency in Yangtze River Delta and Pearl River Delta: a meta Dynamic D.D.F. approach

The Yangtze River Delta and Pearl River Delta are two regions with the highest level of economic development in China, and their port development is at the forefront of the country. This study measures the efficiency of 23 major ports in the two deltas from 2010 to 2018 using the meta Dynamic Directional Distance Function (D.D.F.) model and discusses the technology gap and the reasons for inefficiency of the ports. The research results show that 80% of the ports in these two deltas are inefficient. The Yangtze River Delta’s port efficiency is higher than that of the Pearl River Delta, but the internal efficiency difference of the Yangtze River Delta port cluster is more significant. The efficiency ranking of most ports is inconsistent under the meta-frontier (M.F.) and group frontier (G.F.), and the average technology gap ratio (T.G.R.) of ports in the Pearl River Delta gradually exceeds that in the Yangtze River Delta. The inefficiency of ports in the Pearl River Delta is caused by input factors, and the inefficiency of ports in the Yangtze River Delta is also related to the containerisation level

On the Analysis of Product Appropriateness Principles

The purpose of this study is to explore appropriateness of the various products presented in the market and the application of appropriateness principles to the product design. To obtain appropriateness principles, this study compares and analyzes a variety of products available in the market. After obtaining preliminary principles, many times convergence and analysis are operated for getting more accurate principles. Then, AHP method is used for evaluating importance of every appropriateness principles and appropriateness principles are obtained. And, the appropriateness principles are used to construct the design process of appropriateness product. Finally, some design cases are operated and appropriateness principles are evaluated for the products of design cases. The results of this study are obtained 10 appropriateness principles: freedom, demand, environmental protection, effectiveness, intuition, compliance, simplicity, optimal performance, simplicity, fault tolerance. And, weights of appropriateness principles get in this paper

{6-[2,5-Bis(chloro­meth­yl)-3,4-dihydroxy­tetra­hydro­furan-2-yl­oxy]-3-chloro-4,5-dihydr­oxy-3,4,5,6-tetra­hydro-2H-pyran-2-yl}methyl acetate dihydrate

The title compound, C14H21Cl3O9·2H2O, is a disaccharide constructed from a galactose and a fructose. In the mol­ecular structure, the tetra­hydro­furan five-membered ring and tetra­hydro­pyran six-membered ring assume envelope and chair conformations, respectively. An extensive O—H⋯O hydrogen-bonding network occurs in the crystal structure

Building Intelligent Communication Systems for Handicapped Aphasiacs

This paper presents an intelligent system allowing handicapped aphasiacs to perform basic communication tasks. It has the following three key features: (1) A 6-sensor data glove measures the finger gestures of a patient in terms of the bending degrees of his fingers. (2) A finger language recognition subsystem recognizes language components from the finger gestures. It employs multiple regression analysis to automatically extract proper finger features so that the recognition model can be fast and correctly constructed by a radial basis function neural network. (3) A coordinate-indexed virtual keyboard allows the users to directly access the letters on the keyboard at a practical speed. The system serves as a viable tool for natural and affordable communication for handicapped aphasiacs through continuous finger language input

Experimental Investigation into Mechanical Properties of Nanomaterial-reinforced Table Tennis Rubber

A new table tennis rubber is prepared consisting of carbon nanotubes, zinc oxide and titanium oxide added to a mixture of natural and synthesized rubber. The Nano-reinforced rubber is attached to wooden table tennis blades and patterned with four different surface structures, namely flat, long pimples, short pimples and medium pimples. The results show that of the five rubbers, the Nano-reinforced rubber with a flat surface offers a significantly improved elastic and mechanical performanc