Location of voltage sag source by using artificial neural network

Power quality (PQ) is a major concern for number of electrical equipment such as sophisticated electronics equipment, high efficiency variable speed drive (VSD) and power electronic controller. The most common power quality event is the voltage sag. The objective is to estimate the location of voltage sag source using ANN. In this paper, the multi-monitor based method is used. Based on the simulation results, the voltage deviation (VD) index of voltage sag is calculated and assigned as a training data for ANN. The Radial Basis Function Network (RBFN) is used due to its superior performances (lower training time and errors). The three types of performance analysis considered are coefficient of determination (R2), root mean square error (RMSE) and sum of square error (SSE). The RBFN is developed by using MATLAB software. The proposed method is tested on the CIVANLAR distribution test system and the Permas Jaya distribution network. The voltage sags are simulated using Power World software which is a common simulation tool for power system analysis. The asymmetrical fault namely line to ground (LG) fault, double line to ground (LLG) fault and line to line (LL) fault are applied in the simulation. Based on the simulation results of voltage sag analysis, the highest VD is contributed by LLG for both test systems. Based on the proposed RBFN results, the best performance analysis are R2, RMSE and SSE of 0.9999, 5.24E-04 and 3.90E-05, respectively. Based on the results, the highest VD shows the location of voltage sag source in that system. The proposed RBFN accurately identifies the location of voltage sag source for both test systems

Detection of streptomycin residues in local meat of bovine and ovine

From meat retails in Mosul province, forty-five meat samples of local ovine and bovine (23 bovine samples and 22 ovine samples) were collected. The period of collection was during November 2010 to May 2011, by means of multistage random sampling for detection of streptomycin residues. Enzyme linked immunosorbent assay (ELISA) was used for detection of streptomycin residues. The results revealed that eleven ovine meat samples (50%) were positive to streptomycin residue, with a mean value 35.06 µg kg-1, while 14 bovine meat samples (60.86%) were positive to residual streptomycin with a mean value 59.56 µg kg-1. From the results, it is clear that all tested meat samples (ovine and bovine) were safe enough for human consumption

Calibration of ZMPT101B voltage sensor module using polynomial regression for accurate load monitoring

Smart Electricity is quickly developing as the results of advancements in sensor technology. The accuracy of a sensing device is the backbone of every measurement and the fundamental of every electrical quantity measurement is the voltage and current sensing. The sensor calibration in the context of this research means the marking or scaling of the voltage sensor so that it can present accurate sampled voltage from the ADC output using appropriate algorithm. The peakpeak input voltage (measured with a standard FLUKE 115 meter) to the sensor is correlated with the peak-peak ADC output of the sensor using 1 to 5th order polynomial regression, in order to determine the best fitting relationship between them. The arduino microcontroller is used to receive the ADC conversion and is also programmed to calculate the root mean square value of the supply voltage. The analysis of the polynomials shows that the third order polynomial gives the best relationship between the analog input and ADC output. The accuracy of the algorithm is tested in measuring the root mean square values of the supply voltage using instantaneous voltage calculation and peak-peak voltage methods. The error in the measurement is less than 1% in the peak-peak method and less than 2.5% in the instantaneous method for voltage measurements above 50V AC, which is very good for measurements in utility. Therefore, the proposed calibration method will facilitate more accurate voltage and power computing for researchers and designers especially in load monitoring where the applied voltage is 240V or 120V ranges

Non-Linear Buckling Analysis of Non-Prismatic Steel Columns Subjected to Axial Compression Loads

This study investigates the effect of non-uniform cross-section on the behavior of steel columns subjected to axial compression load. A nonlinear finite element model using ANSYS 12.0 has been adopted to investigate the behavior of square and circular steel columns. The steel is assumed to behave as an elastic-plastic material with strain hardening in compression. The type of elements have been used to model the steel; SOLID45. The axial- load displacement curves and the deformation shapes were predicted. A parametric study on columns with square and circular section has been done. All the analyzed columns have the same value of cross-section volume for the column, yielding strength, and boundary conditions with different length of column. The results show that the behavior of non-prismatic column is always by the tapering ratio and the slenderness ratio on the elastic buckling. As the taper ratio increases, the elastic buckling load increases, in the main while the maximum ultimate load occurs in the (prismatic column) comparing with the non-prismatic column. Keywords: Non-uniform cross-section, Steel columns, nonlinear finite element, Elastic buckling load

Optimal Multiprocessor Locking Protocols Under FIFO Scheduling

Real-time locking protocols are typically designed to reduce any priority-inversion blocking (pi-blocking) a task may incur while waiting to access a shared resource. For the multiprocessor case, a number of such protocols have been developed that ensure asymptotically optimal pi-blocking bounds under job-level fixed-priority scheduling. Unfortunately, no optimal multiprocessor real-time locking protocols are known that ensure tight pi-blocking bounds under any scheduler. This paper presents the first such protocols. Specifically, protocols are presented for mutual exclusion, reader-writer synchronization, and k-exclusion that are optimal under first-in-first-out (FIFO) scheduling when schedulability analysis treats suspension times as computation. Experiments are presented that demonstrate the effectiveness of these protocols

Impact of Holes on the Buckling of RHS Steel Column

في هذا البحث تم اجراء دراسة عملية ونظرية لتأثير الفتحات في تصرف الاعمدة الفولاذية المستطيلة المجوفة المعرضة لأحمال ضغط محورية. تم فحص عينات لدراسة التحمل الاقصى وتصرف حمل-أزاحات محورية للأعمدة الفولاذية. في هذا البحث تم استخدام نظرية العناصر المحددة المتمثلة ببرنامج ANSYS 12.0 لتحليل تصرف الاعمدة المستطيلة المجوفة مع فتحات. في الجزء العملي استعملت اربعة وعشرون نموذج من الاعمدة الفولاذية المستطيلة المجوفة بزوايا مدورة الذي له ابعاد مقطع 50*80)) ملم وارتفاع 250,500)) ملم و بسمك (1.25,4 and 6) ملم مع ابعاد حفرة ((80*α)*80) ملم بحيث ان α مساوية الى 0.2,0.4,0.6 and 0.8)) . تم فحص اربعة وعشرون من الاعمدة الفولاذية تحت حمل انضغاط من اجل التحقيق في تأثير الحفرة في المقاومة القصوى للأعمدة المستطيلة المجوفة. أظهرت النتائج العملية أن طريقة الفشل النموذجية لجميع العينات المجوفة المختبرة كانت التواء المحلي. وأظهرت النتائج التي تم اختبارها أن زيادة ابعاد الحفرة يؤدي إلى الحد من الحمل الاقصى للعمود يصل إلى 75%. وأظهرت النتائج تقليل الحمل بنسبة  94.7%بسبب انخفاض سمك العمود بينما يكون حجم الثقب ثابتا. ينخفض ​​الحمل التواء بنسبة  84.62%عندما يتغير موفع الحفرة  من 0.25L إلى 0.75L. يمكن إجراء الحفرة في منتصف العمود مع بعد يصل إلى 0.4 من طول العمود. و AISC(2005) يعرض القيم الأقرب إلى النتائج العملية  لمقاومة خضوع الانضغاط. أدى تأثير زيادة نسبة الانحناء ونسبة السمك إلى مساحة (t / A) مما أدى إلى خفض مقومة الانضغاط الحرجة وفشل العمود مع حجم كبير من الحفرة و (t / A) نسبة أقل من  0.74%ويرجع ذلك إلى الانبعاج المحلي في حين أن فشل الإبزيم العالمي كان معتمدا للعمود مع حجم صغير من الحفرة و (t / A) نسبة فوق 0.74%. وأظهرت النتائج وجود اتفاق معقول بين النتائج العملية والنظرية وكان الفرق يتراوح بين(1.28-14.88)%.This study presented an experimental and theoretical study on the effect of hole on the behavior of rectangular hollow steel columns subjected to axial compression load. Specimens were tested to investigated the ultimate capacity and the load- axial displacement behavior of steel columns. In this paper finite element analysis is done by using general purpose ANSYS 12.0 to investigate the behavior of rectangular hollow steel column with hole. In the experimental work, rectangular hollow steel columns with rounded corners were used in the constriction of the specimens which have dimensions of cross section (50*80)mm and height of (250 and 500)mm with thickness of (1.25,4 and 6)mm with hole ((α*80)*80)mm when α is equal to (0.2,0.4,0.6 and 0.8). Twenty four columns under compression load were tested in order to investigate the effect of hole on the ultimate load of rectangular hollow steel column. The experimental results indicated that the typical failure  mode for all the tested hollow specimen was the local buckling. The tested results indicated that the increasing of hole dimension leads to reduction in ultimate loads of tested column to 75%. The results show the reducing of load by 94.7% due to decreasing  the thickness of  column while the hole size is constant (0.2*80*80). The buckling load decreases by 84.62% when hole position changes from Lo=0.25L to 0.75L. Holes can be made in the middle of column with dimension up to 0.4 of column\u27s length. The AISC (2005) presents the values closest to the experimental results for the nominal yielding compressive strength. The effect for increasing of slendeness ratio and thickness to area ratio(t/A) leading to decreacing the critical stresses and the failure of column with large size of hole and (t/A) ratio less than 0.74% was due to lacal  buckling while the global buckling failure was abserve for column with small size of hole and (t/A) ratio above than 0.74%. The compersion  between the experimental and theoretical results showed a reasonable agreement and the difference was in the range (1.28-14.88)%.     &nbsp

Open Problem Resolved: The "Two" in Existing Multiprocessor PI-Blocking Bounds Is Fundamental

The goal of a real-time locking protocol is to reduce any priority-inversion blocking (pi-blocking) a task may incur while waiting to access a shared resource. For mutual-exclusion sharing on an m-processor platform, the best existing lower bound on per-task pi-blocking under suspension-oblivious analysis is a (trivial) lower bound of (m-1) request lengths under any job-level fixed-priority (JLFP) scheduler. Surprisingly, most asymptotically optimal locking protocols achieve a per-task pi-blocking upper bound of (2m-1) request lengths under JLFP scheduling, even though a range of very different mechanisms are used in these protocols. This paper closes the gap between these existing lower and upper bounds by establishing a lower bound of (2m-2) request lengths under global fixed-priority (G-FP) and global earliest-deadline-first (G-EDF) scheduling. This paper also shows that worst-case per-task pi-blocking can be arbitrarily close to (2m-1) request lengths for locking protocols that satisfy a certain property that is met by most (if not all) existing locking protocols. These results imply that most known asymptotically optimal locking protocols are almost truly optimal (not just asymptotic) under G-FP and G-EDF scheduling

Surface topography of hydroxyapatite affects ROS17/2.8 cells response

Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan’s multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity

Tight Tardiness Bounds for Pseudo-Harmonic Tasks Under Global-EDF-Like Schedulers

The global earliest-deadline-first (GEDF) scheduler and its variants are soft-real-time (SRT) optimal for periodic/sporadic tasks, meaning they provide bounded tardiness so long as the underlying platform is not over-utilized. Although their SRT-optimality has long been known, tight tardiness bounds for these schedulers have remained elusive. In this paper, a tardiness bound, that does not depend on the processor or task count, is derived for pseudo-harmonic periodic tasks, which are commonly used in practice, under global-EDF-like (GEL) schedulers. This class of schedulers includes both GEDF and first-in-first-out (FIFO). This bound is shown to be generally tight via an example. Furthermore, it is shown that exact tardiness bounds for GEL-scheduled pseudo-harmonic periodic tasks can be computed in pseudo-polynomial time