Architecture–based reliability analysis is necessary for a software application that is developed using the component–based software development paradigm. Prevalent architecture–based analysis techniques represent the application architecture by a Markov process, which may be adequate in the context of an application with a general– purpose architecture. The Markov process, however, is not adeq...

In the present contribution optimization and simulation methods are investigated in order to attain optimal scaling of labial organ pipes. The goal is to determine the optimal dimensions of the pipe, by which a desired steady state sound spectrum can be achieved. By modifying the geometry of the pipe body, the eigenfrequencies of the acoustic resonator can be tuned in order to amplify or repres...

Unix-based operating systems feature several forms of Inter-Process Communication (IPC) including pipes, Unix domain sockets, TCP/IP sockets, FIFOs, semaphores, and signals. Although these mechanisms provide similar services, each is designed differently with varying levels of performance. To better understand how these mechanisms work and why they perform the way they do, their implementations...

Closed Circuit Television (CCTV) surveys are used widely in North America to assess the structural integrity of underground pipes. The video images are examined visually and classified into grades according to degrees of damage. The human eye is extremely effective at recognition and classification, but it is not suitable for assessing pipe defects in thousand of miles of pipeline images due to...

We extend a general network theorem of Calvert and Keady (CK) relating to the minimum number of arcs needed to guarantee the occurrence of the Braess Paradox. We rephrase the CK theorems and express our proof in the terminology of traffic networks. CK described their theorem in relation to a two-terminal network of liquid in pipes. “Approximately stated, it is: if every relationship between flo...

Green buildings are increasingly being plumbed with crosslinked polyethylene (PEX) potable water pipe. Tap water quality was investigated at a six month old plumbing system and chemical and odor quality impacts of six PEX pipe brands were examined. Eleven PEX related contaminants were found in the plumbing system; one regulated (toluene) and several unregulated: Antioxidant degradation products...

The purpose of this research is to realize a small robot which can negotiate pipes whose diameter varies widely during the robot’s course. A new in-pipe locomotion mechanism named “snaking drive” is proposed in this paper and its potential and fundamental characteristics are shown with experimental data of the prototype model. First, in the sections 2 to 5, the basic traveling characteristics o...