Almost and Nearly Isosceles Pythagorean Triples

This work is about extended pythagorean triples, called NPT, APT, and AI-PT. We generate infinitely many NPTs and APTs and then develop algorithms for infinitely many AI-PTs. Since AI-PT (a,b,c) is of a-b=1, we ask generally for PT (a,b,c) satisfying |a-b|=k for any k∈N. These triples are solutions of certain diophantine equations

Models and Application of Firefighting Vulnerability

AbstractGeographic information systems (GIS) have been applied to analyze the efficiency and effectiveness of public facility services such as fire stations, police stations and day-care centers. Regardless of the scientific contribution of such an approach, there are numerous limitations to follow the rules or optimized suggestions due to high land price and other societal factors. In the present study, we narrowed the scope to firefighting services: how to decrease firefighting dismissals and help firefighters recognize the situation of fire events before arriving at the fire scenes. The absolute time from the fire station to the fire scene was considered to be the Mobility Kill Zone. Narrow roads and illegal parking were classified as the Operation Kill Zone. Areas with identified hazardous commodities and toxic substances were classified as the Identified Hazardous Zone. The areas cluttered with fire safety management objects were classified as the Fire Vulnerability Zone. Four models were suggested in our previous research and in the present study, we elaborated upon the models and examined new information technology (IT) to implement the models in rural and urban areas

In situ endoscopic observation of higher-order mode conversion in a microwave mode converter based on an electro-optic probe system

Visualizing the electromagnetic field transformation inside a microwave mode conversion region has been considered to be only realizable by simulation studies. For the first time, we present a comprehensive experimental observation of the electric field transformation occurring inside a metallic waveguide TE01-to-TE02 mode converter. An efficient electro-optic (EO) probe and its associated probing system were used for measuring the electric field pattern in the external near-field region as well as in the internal and penetrated region of the mode converter. Utilizing the optically measured field patterns at the aperture of the mode converter, the conversion performance from the TE01 mode to the TE02 mode can be also evaluated. Experimentally measured field patterns near the apertures show excellent agreement with simulation data. The mode conversion to the next higher-order mode (TE01 to TE02) was experimentally demonstrated with phase-stabilized and field-animated post processing. The presented in situ endoscopic photonic measurement technique for the field evolution inside a semi-enclosed structure could be used for visually inspecting manufacturing errors in fabricated structures, and could be of great interest for research on higher-order mode formation and transmission.open0

Stochastic Reward Net-based Modeling Approach for Availability Quantification of Data Center Systems

Availability quantification and prediction of IT infrastructure in data centers are of paramount importance for online business enterprises. In this chapter, we present comprehensive availability models for practical case studies in order to demonstrate a state-space stochastic reward net model for typical data center systems for quantitative assessment of system availability. We present stochastic reward net models of a virtualized server system, a data center network based on DCell topology, and a conceptual data center for disaster tolerance. The systems are then evaluated against various metrics of interest, including steady state availability, downtime and downtime cost, and sensitivity analysis

Sensor grid middleware metamodeling and analysis

Sensor grid is a platform that combines wireless sensor networks and grid computing with the aim of exploiting the complementary advantages of the two systems. Proper integration of these distinct systems into effective, logically single platform is challenging. This paper presents an approach for practical sensor grid implementation and management. The proposed approach uses a metamodeling technique and performance analysis and tuning as well as a middleware infrastructure that enable practical sensor grid implementation and management. The paper presents our implementation and analysis of the sensor grid. © 2014 Srimathi Chandrasekaran et al

On Partial Sum of Tribonacci Numbers

We study the sum ( , ) = ∑ =0 + of step apart Tribonacci numbers for any 1 ≤ ≤ . We prove that ( , ) satisfies certain −3 + with integers , , , and

Experimental observation of the effect of aftercavity interaction in a depressed collector gyrotron oscillator

This paper presents the experimental observation of the effect of an aftercavity interaction (ACI) in a depressed collector gyrotron oscillator. The gyrotron generates an output power of 1.5 MW at 110 GHz in 3 ??s pulses with a 96 kV and 40 A electron beam and has a single-stage depressed collector. The ACI arises from an unintended cyclotron resonant interaction between the microwave beam traveling out from the cavity and the gyrating electron beam. The interaction occurs in the uptaper of the launcher, immediately downstream from the cavity, where the magnetic field is slightly lower than its value in the cavity region. The ACI results in a reduction in efficiency since the electron beam tends to extract power from the wave. There is also a broadening of the spent beam energy profile, which reduces the effectiveness of the depressed collector and in turn limits the overall efficiency of a gyrotron. Measurements of the maximum depression voltage of the collector vs beam current at 96 kV are compared with simulations from the MAGY code [M. Botton, IEEE Trans. Plasma Sci. 26, 882 (1998)]. Excellent agreement is obtained between theory and experiment but only if the ACI is included. In the present experiment, it is estimated that the observed efficiency of 50% would have been about 60% in the absence of the ACI. These results verify the role of the ACI in reducing the efficiency of the gyrotron interaction.open151

Numerical estimation on free electrons generated by shielded radioactive materials under various gaseous environments

We report simulation results on generation of free electrons due to the presence of radioactive materials under controlled pressure and gases using a general Monte Carlo transport code (MCNPX). A radioactive material decays to lower atomic number, simultaneously producing high energy gamma rays that can generate free electrons via various scattering mechanisms. This paper shows detailed simulation works for answering how many free electrons can be generated under the existence of shielded radioactive materials as a function of pressure and types of gases.open0