Constant frequency output two stage induction machine systems Patent

Double-induction variable speed system for constant-frequency electrical power generatio

Induction generator produces constant-frequency voltage from variable-speed drive

Two-stage polyphase generator is usable as induction motor operable over range of speeds while powered from constant frequency source. It requires neither slip rings nor special adjustable-frequency power supplies or external reactive sources

Fuzzy Logic and Singular Value Decomposition based Through Wall Image Enhancement

Singular value decomposition based through wall image enhancement is proposed which is capable of discriminating target, noise and clutter signals. The overlapping boundaries of clutter, noise and target signals are separated using fuzzy logic. Fuzzy inference engine is used to assign weights to different spectral components. K-means clustering is used for suitable selection of fuzzy parameters. Proposed scheme significantly works well for extracting multiple targets in heavy cluttered through wall images. Simulation results are compared on the basis of mean square error, peak signal to noise ratio and visual inspection

Equivalent Binary Quadratic Form and the Extended Modular Group

Extended modular group $\bar{\Pi}=$, where R:z\rightarrow -\bar{z}, \sim T:z\rightarrow\frac{-1}{z},\simU:z\rightarrow\frac{-1}{z +1} , has been used to study some properties of the binary quadratic forms whose base points lie in the point set fundamental region $F_{\bar{\Pi}}$ (See \cite{Tekcan1, Flath}). In this paper we look at how base points have been used in the study of equivalent binary quadratic forms, and we prove that two positive definite forms are equivalent if and only if the base point of one form is mapped onto the base point of the other form under the action of the extended modular group and any positive definite integral form can be transformed into the reduced form of the same discriminant under the action of the extended modular group and extend these results for the subset \QQ^*(\sqrt{-n}) of the imaginary quadratic field \QQ(\sqrt{-m}).Comment: Paper contains two figures and twelve page

A brief report of research activities of Indus Institute of Higher Eduction (IIHE) Karachi, Pakistan 2007-2010 (August)

An attempt has been made to summarize the past performance of “Indus Institute of Higher Education” (IIHE) relating to research work already done or being done in its different faculties. In fact this Institute is actively involved in research activities but never reflected them in any correspondence. This Institute is regularly publishing its academic journal with contribution from within the country and qualified researchers from abroad. Four active researchers, of this Institute, are registered and contributing articles in research journals and MPRA working paper series at national and international level. For the students of Bachelors and Masters Research Projects are mandatory for award of Degrees. The Institute has already started M.Phil and Ph.D programs and from the first batch of M.Phil a few students have already submitted their Thesis. The 2nd batch of M.Phil [16 students) is doing its thesis writing. As per HEC’s requirements every faculty have to contribute at least 2 articles at national and international level. In this respect the IIHE has planned to publish one working paper series and four e-journals in the field of textile, engineering and technology, education and economics. The management has decided to make it mandatory for every faculty to contribute at least two research papers/reports per annum. To achieve this objective Research Office has decided to train all the faculty members of the Institute through workshops etc. in order to creating awareness in Faculty members as well as students of MBA, BBA, M.Ed. and B.S.T. to use research-based structure and methodologies that are requisite for M.Phil. Or Ph.D students.Research Activities; IIHE, Cell; RePEc; Journal

Modeling and management of fire-induced pressures in a model apartment

Fire developing in a mechanically ventilated airtight compartment can induce high pressure. The significance of this arisen pressure and the risks involved with it were explored in this study. Previously, no effort has been made to study the impact of realistic fire growth rates over compartment pressures in a residential setting. This research is based on a fire development scenario exhibiting a model apartment in a multi-story residential building. This thesis study documents the behavior of fire-induced compartment pressure relative to involved variables. This thesis also devises an alternate method of computing fire-induced pressures in airtight compartments. Finally, this thesis proposes solutions for the management of the encountered overpressure under apartment fire scenarios. Fire-induced pressure as a function of fire growth rate, envelope airtightness, and damper configuration was studied using Fire Dynamics Simulator (FDS). Pressure behavior, peak pressure values, and variable trends were the focus of this study. Results suggest that pressure increases with faster fire growth rate and overall airtightness of the compartment. In addition, the sensitivity of pressure to a parameter value seemed to increase when moving towards a faster fire growth or increased overall air-tightness of the compartment. It was found that the pressure rise can risk the occupants’ escape from the inward-opening door for medium and faster fire growth rates. Overpressure can cause structural damage to a near-zero envelope with a fast or ultra-fast fire growth rate. An analytical model was developed from the basic assumption of an ideal gas as an alternate way to capture the pressure rise related to compartment fire scenarios. The model was validated with the known FOA and AALTO experiments’ simulation and experimental data. In comparison to FDS results, the analytical model captured the pressure behavior in an apartment fire scenario with reasonable accuracy. The positive peak pressures were captured with an average difference of 5%. The model was found reliable in all configurations of input variables. In order to deal with the overpressures encountered, recommendations were made for additional leakage areas required to diminish the overpressure under the threshold safety limits of occupant safety and structural integrity. The findings were also verified using the FDS simulations. Finally, for managing the pressure in practical scenarios, the pressure threshold limits were converted into their equivalent bulk leakage area limits for different ventilation configurations

Delayed surgical debridement in pediatric open fractures: a systematic review and meta-analysis.

Purpose: Open fractures are considered orthopedic emergencies that are traditionally treated with surgical debridement within 6 h of injury to prevent infection. However, this proclaimed “6-h rule” is arbitrary and not based on rigorous scientific evidence. The aim of our study was to systematically review the literature that compares late (>6 h from the time of injury) to early (<6 h from the time of injury) surgical debridement of pediatric open fractures. Methods: We searched several databases from 1946 to 2013 for any observational or experimental studies that evaluated late and early surgical debridement of pediatric open fractures. We performed a meta-analysis using a random effects model to pool odds ratios for a comparison of infection rates between children undergoing late versus early surgical debridement. We also investigated the infection rates in upper- and lower-limb pediatric open fractures. Descriptive, quantitative, and qualitative data were extracted. Results: Of the 12 articles identified, three studies (retrospective cohort studies) were eligible for the meta-analysis, encompassing a total of 714 open fractures. The pooled odds ratio (OR = 0.79) for infection between late and early surgical debridement was in favor of late surgical debridement but was not statistically significant (95 % CI 0.32, 1.99; p = 0.38, I 2 = 0 %). No significant difference in infection rate was detected between pediatric open fractures in the upper and lower limbs according to the time threshold in the included studies (OR = 0.72, 95 % CI 0.29, 1.82; p = 0.40, I 2 = 0 %). Conclusions: The cumulative evidence does not, at present, indicate an association between late surgical debridement and higher infection rates in pediatric open fractures. However, initial expedient surgical debridement of open fractures in children should always remain the rule. Thus, multi-center randomized controlled trials or prospective cohort studies will be able to answer this question with more certainty and a higher level of evidence