This paper describes a scheme, AEDCF-CW/PF, that allows stations implementing IEEE 802.11e to have varying maximum contention window sizes and persistence factors. The values of these parameters are adjusted using knowledge of the station’s collision probability. Our research indicates that stations implementing this scheme experience much lower frame delays and frame dropping probabilities und...

In this technical note, analytical solutions for the elastic buckling of heavy columns with various combinations of end conditions are derived, for the first time, in terms of generalized hypergeometric functions. The benchmark solutions may be used to assess the accuracy of approximate formulas and numerical solutions. DOI: 10.1061/ ASCE 0733-9399 2008 134:1 116 CE Database subject headings: C...

This paper describes a method of supporting teachers ’ evaluation work of students ’ programs. In programming education, programming exercise courses play an important role, because writing programs is indispensable to learning programming. In programming exercise classes, however, the teacher’s loads of evaluation tend to be very heavy because the teacher has to read so many programs and repor...

Fluid power plays a crucial role in modern industry Owing to the high capability to take up heavy loads with little amount of energy consumption. ease and accuracy of control. fluid power system are widely adopted in many different areas like highway conveyors mining and manufacturing. This paper is to give an overview of the application of fluid power system in discrete part manufacturing The ...

This paper describes the model and prototype implementation of a knowledge assessment framework based on problem management components. In order to support student testing with complex problem types and enable usage of rich graphical user interfaces for solution inputting, we have developed an e-examination model in which a component that can generate complex questions and evaluate students’ so...

The traditional Database partitioning has failed in multi-tenant shared scheme database; this paper proposed a mixed Partitioning Approach. By integrating vertical and horizontal partitioning, we can adaptive expand the multi-tenant database according to the number of server nodes or we can make an optimal partitioning. Experimental results show that our approach can improve the performance of ...

Comparative studies of x-radiation effects on both isolated cold blooded (frog) and intact warm blooded (rabbit) muscles were performed. Frog muscles irradiated with doses above 50 kr showed early fatigue, contracture, prolongation of relaxation time, decreased contraction amplitude for heavy loads, and histologic changes noticeable 8 hours after exposure. Rabbit muscles exposed to 72 kr exhibi...

AIM To analyze neuromuscular activity patterns of the trunk in healthy controls (H) and back pain patients (BPP) during one-handed lifting of light to heavy loads. METHODS After assessment of back pain (graded chronic pain scale according to von Korff) all subjects (n = 43) performed a warm-up (treadmill walking). Next, subjects were instructed to lift 3 × a 20 kg weight placed in front of th...

OBJECTIVE Metal contamination of humans in war areas has rarely been investigated. Weaponry's heavy metals become environmentally stable war remnants and accumulate in living things. They also pose health risks in terms of prenatal intake, with potential long term risks for reproductive and children's health. We studied the contribution of military attacks to the load of 23 metals in the hair o...

OBJECTIVES To examine the dose-response relationship between cumulative exposure to kneeling and squatting as well as to lifting and carrying of loads and symptomatic knee osteoarthritis (OA) in a population-based case-control study. METHODS In five orthopedic clinics and five practices we recruited 295 male patients aged 25 to 70 with radiographically confirmed knee osteoarthritis associated...