Sharif Digital Repository

This paper presents a simulation-based study of the delay fault testing in CMOS logic circuits. A novel built-in self-test (BIST) technique is presented for detecting delay faults in this logic family. This scheme does not need test-pattern generation, and thus can be used for robust on-line testing. Simulation results for area, delay, and power overheads are presented. © 2007 IEEE  

A rescheduling method for new order arrival is presented based on the concept of dynamic pegging in multi-level production. Upon the arrival of new, unplanned orders, dynamic pegging enables the re-assignment of the Work-In-Progress (WIP) to the existing or newly arrived orders in such a way that the cost of rescheduling is minimized. A simple yet inspiring Mixed Integer Programming (MIP) model is proposed that combines dynamic pegging with rescheduling. The resulting schedules are compared with the ones obtained from two other basic rescheduling approaches. Analysis of the comparisons confirm the superiority of the proposed method in terms of total rescheduling costs. © 2019  

This paper presents a new predictive-reactive rescheduling method for adjusting production schedules in response to the unplanned arrival of new orders in multi-level production. It is based on the concept of dynamic pegging, which enables the reassignment of the Work-In-Progress (WIP) to the existing or newly arrived orders at the time of rescheduling. Extending our previous work on reactive rescheduling with dynamic pegging, the new approach incorporates a probabilistic predictive model of new order arrival in the initial scheduling at the begging of the scheduling horizon. A Mixed Integer Programming (MIP) model is developed for two-phase, predictive-reactive scheduling before and after... 

This paper presents a simulation-based study of the stuck-open fault testing in CMOS logic circuits. A novel built-in self-test (BIST) technique is presented for detecting stuck-open faults in these logic families. This scheme does not need test-pattern generation, and thus can be used for robust on-line testing. Simulation results for area, delay, and power overheads are presented. © 2007 IEEE  

In this paper a new predictive-reactive rescheduling method is presented based on the dynamic pegging concept. Scheduling adjustments in a multi-level, mixed-model production system are invoked in response to the unplanned events, such as new order arrival, changes in due dates, and order cancellation. By using the dynamic pegging approach at the time of rescheduling, Work-In-Progress (WIP) can be reassigned to the existing or new orders. Based on our previous work on reactive-only rescheduling with dynamic pegging, a Mixed Integer Programming (MIP) model is developed for predictive-reactive scheduling of new orders of different product types that arrive following exponential distribution. A... 

One of the significant problems of the upstream flow assurance community is precipitation or deposition of asphaltene that leads to affect the economics of oil production seriously. Knowledge of asphaltene onset pressure (AOP) and amount of asphaltene precipitation in the change of temperature, pressure, and composition is the essential information for preventing this problem. Recent studies have shown that thermodynamic models based on the solubility nature of asphaltenes using an equation of state (EOS) are the most effective approach to asphaltene behavior modeling. In this research, the common version of the SAFT equation, known as the Perturbed Chain form of Statistical Association... 

In this work, the possibility of capacity enhancement in the South Pars Gas Complex of Iran has been studied. Mass balance is studied and data validation and reconciliation have been carried out in 5th refinery of South Pars Gas Complex in order to achieve the reliable data of the plant. Then the possibility of capacity increase has been studied, taking into account the important parameters such as alteration of the plant pressure profile. Calculation of the key parameters for different equipment at higher feed rate, specified the unit of operations which may have trouble during the capacity enhancement. The performance of export gas compressors, dehydration unit and High-Integrity Pressure... 

A novel magnetic heterogeneous copper catalyst was synthesized by immobilization of copper ions onto triazole functionalized Fe3O4. The catalyst was fully characterized by FT-IR, TGA, CHN, SEM, TEM, EDX and atomic adsorption spectroscopy. The resulting catalyst was used in the synthesis of 1,2,3-triazoles via a one-pot three component reaction of alkynes, alkyl halides, sodium azides under green conditions. The catalyst was reused ten times and no significant loss of activity was observed  

Strengthening is often a necessary measure to overcome an unsatisfactory deficient situation or where a new code requires the structure or a member of it to be modified to achieve new requirements. In the engineering practice such restraint to lateral dilation, indicated by the name of confinement, has been traditionally provided to compression members through steel transverse reinforcement in the form of spirals, circular hoops or rectangular ties. Steel and concrete jackets are other techniques for providing additional confinement for compression members, too. This paper presents the results of experimental and analytical study on the application of strapping technique for retrofitting of... 

A new heterogeneous and highly dispersive nanocatalyst in water was prepared by the immobilization of Cu2+ onto glucose on Fe3O4. The catalyst was fully characterized by FT-IR, TGA, CHN, SEM, EDX, and atomic absorption spectroscopy. The synthesized catalyst was used in the synthesis of different derivatives of 1,2,3-triazole via a one-pot three-component reaction of alkynes, alkyl halides, and sodium azide. To the best of our knowledge, this novel catalyst adheres to the principles of green chemistry. The nanocatalyst could be recycled and reused in several runs without significant loss of activity  

In this paper, a novel steganographic method is proposed which is based on the spatial domain: Least Significant Bit (LSB). The LSB matching method proposed by Mielikainen utilizes a binary function to reduce the number of changed pixel values. While in this paper a bipolar evaluating system is proposed to assess the performance of different orders for LSB matching. Afterward a genetic algorithm strategy is employed to search for an optimal solution among all the permutation orders. The experimental results show that by employing the proposed bipolar evaluating system, the distortion of the stego-image is reduced while the probability of detection is decreased  

Predicting the effective elastic properties of carbon nanotube-reinforced nanocomposites is of great interest to many structural designers and engineers for improving material and configuration design in recent years. In this paper, a finite element model of a CNT composite has been developed using the Representative volume element (RVE) to evaluate the effective material properties of nanocomposites. Based on this model, the effects of geometrical characteristics such as the aspect ratio, orientation and volume fraction of the CNTs in conjunction with the interphase behavior on the mechanical properties of the nanocomposites are elucidated and the elastic properties of a complex polymeric... 

Concepts developed in the gravitational lensing techniques such as shear, convergence, tangential, and radial arcs maybe used to see how tenable inhomogeneous models proposed to explain the acceleration of the universe models are. We study the widely discussed Lemaitre-Tolman-Bondi (LTB) cosmological models. It turns out that for the observer sitting at origin of a global LTB solution the shear vanishes as in the Friedmann-Robertson-Walker models, while the value of convergence is different, which may lead to observable cosmological effects. We also consider Swiss-cheese models proposed recently based on LTB with an observer sitting in the Friedmann-Robertson-Walker part. It turns out that... 

We used a method to evaluate angular accuracy for air showers direction recorded by a pentagon array of scintillation detectors. This is achieved by using the coincidences between the air showers recorded by the two sub-arrays. Also, using the CORSIKA code the angular precision of this array and the effect of inherent error on it is obtained at different energies of the primary particles and at different zenith angles. © 2020 Elsevier B.V  

The seismic behavior of stainless-steel built-up box columns subjected to constant axial loads and cyclic lateral deformation that are used in special moment frames (SMFs) has been investigated through finite element (FE) analysis. A total of 208 numerical models were conducted to cover a range of parameters affecting the seismic behavior of the columns. These include the web slenderness ratio, flange slenderness ratio, global slenderness ratio, axial load level, and lateral loading protocol. The performance indices of overstrength factor, axial shortening, out-of-plane deformation, plastic hinge length, and rotation capacity were calculated and compared. Local buckling of the columns also... 

An efficient and facile one-pot, multi-component reaction for the regio- and diastereoselective synthesis of novel dispirocyclopentanebisoxindoles has been reported by a reaction between phenyl-2-(triphenylphosphoranylidene)ethanone and isatin derivatives. The great advantages of this synthetic protocol are the minimal reaction steps, short reaction time, and operational simplicity. In consequence, a variety of new dispirocyclopentanebisoxindole derivatives with potential medicinal applications were synthesized through one-pot and multi-component reaction in high to excellent yields. © 2023 Elsevier Ltd  

An efficient and one-pot synthesis of thiopyrano[2,3-b]indole derivatives via Hetero Diels-Alder reaction of α,β-Unsaturated thio-oxindoles with electron poor acetylenes and Cyclic Dienophiles is described. In the proposed method the reaction is performed under neutral and one-pot reaction conditions, and also the substances can be mixed without any activation or modification and without using any catalysts  

A novel heterogeneous copper catalyst was synthesized in which poly(1-vinyl imidazole-co-ionic liquid) was used as a solid heterogeneous support. The catalyst was readily synthesized in a large scale amount. The catalyst has a high loading level of copper ions and can be used in low weight percentages. The resulting catalyst was highly active in the preparation of triazoles by the Huisgen 1,3-dipolar cycloaddition method. In some cases the catalytic turnover number and frequency reached 70 002 and 3889 h-1, respectively. The catalyst was recycled many times without significant loss of activity. This journal is  

Supported gold(III) on poly(ionic liquid) coated on magnetic nanoparticles produced a highly active, stable, recoverable and high loading for the synthesis of propargylamines (A3 coupling reaction) under green conditions. The reaction of aldehyde, secondary amine and alkyne were followed in aqueous media. The catalyst was characterized by TEM, TGA, AAS, FT-IR, XRD and EDX. A broad diversity of aldehydes, secondary amines, and alkynes, and a good to excellent yield of corresponding propargylamines were synthesized using 1.0% Au. The catalyst was easily recovered and reused 10 times without significant loss of activity  

A new one-pot synthesis of thieno[2,3-b]indole ring systems is described. Condensation of cyclohexyl isocyanide with indolin-2-thiones yielded 3-cyclohexyaminomethylene-indolin-2-thiones, which upon reaction with α-halocarbonyl compounds produced the title compounds. © Georg Thieme Verlag Stuttgart