475 research outputs found
Crime mapping and spatial analysis
Crime maps are becoming significant tools in crime and justice. Advances in the areas of information
technology and Geographic Information Systems (GIS) have opened new opportunities
for the use of digital mapping in crime control and prevention programs. Crime maps are also
valuable for the study of the ecology and the locational aspects of crime. Maps enable areas of
unusually high or low concentration of crime to be visually identified. Maps are however only
pictorial representations of the results of more or less complex spatial data analyses.
A hierarchical model dealing with crime analysis is proposed and applied to the regional analysis
of crime in Tehran, the model helps to identify spatial concentration of crimes in specific
area (area based method). In area-based methods, crime data are aggregated into geographical
areas such as blocks, precincts, and for each area, the analyst computes a measure of crime
value. Multicriteria evaluation concept has been used to assess the crime rate in various blocks a
discrete (part) of Tehran city. In this part we used two methods for crime density assessment:
• Crime assessment based on crime per block,
• Crime assessment based on density of crime per population.
After determination of hot spots based on two methods mentioned above spatial function is
used to find suitable location to establish new police station or direct patrol to the hot spots to
reduce of crime
Supply chain single vendor – Single buyer inventory model with price-dependent demand
Purpose: The aim of this article is developing an integrated production-inventory-marketing model for a two-stage supply chain. The demand rate is considered as the Iso-elastic decreasing function of the selling price. The main research goal of the article is to obtain the optimal values of the selling price, order quantity and number of shipments for the proposed model under independent and also joint optimization. In addition, the effects of the model’s parameters on the optimal solution are investigated.
Design/methodology/approach: Mathematical modeling is used to obtain the joint total profit function of the supply chain. Then, the iterative solution algorithm is presented to solve the model and determine the optimal solution.
Findings and Originality/value: It is observed that under joint optimization, the demand rate and the supply chain’s profit are higher than their values under independent optimization, especially for the more price sensitive demand. Therefore, coordination between the buyer and the vendor is advantageous for the supply chain. On the other hand, joint optimization will be less beneficial when there isn’t a significant difference between the buyer’s and the vendor’s holding costs.
Originality/value: The contribution of the article is determining the ordering and pricing policy jointly in the supply chain, which contains one vendor and one buyer while the demand rate is the Iso-elastic function of the selling pricePeer Reviewe
Multiphysic Design and Modeling of Rotating Electrical Machines
This paper presents a general overview on design process of electrical machines considering a multiphysic point of view, and a road map for a comprehensive design approach is drawn. The objective multi-physical criterion including electromagnetism and mechanics physics, thermodynamics, fluid dynamics, structural dynamics, noise and vibration are discussed. Also, various modelling methodologies are presented and compared in terms of computational-time resources and accuracy. Current state of art in this approach will be presented highlighting the advantages and disadvantages of such methodologies
Union of Low-Rank Subspaces Detector
The problem of signal detection using a flexible and general model is
considered. Due to applicability and flexibility of sparse signal
representation and approximation, it has attracted a lot of attention in many
signal processing areas. In this paper, we propose a new detection method based
on sparse decomposition in a union of subspaces (UoS) model. Our proposed
detector uses a dictionary that can be interpreted as a bank of matched
subspaces. This improves the performance of signal detection, as it is a
generalization for detectors. Low-rank assumption for the desired signals
implies that the representations of these signals in terms of some proper bases
would be sparse. Our proposed detector exploits sparsity in its decision rule.
We demonstrate the high efficiency of our method in the cases of voice activity
detection in speech processing
Assessing growth parameters of children with congenital hypothyroidism subject to levothyroxine treatment compared to normal growth parameters in healthy newborns
Background and aims: Congenital hypothyroidism (CH) is one of the most common treatable physical growth disorders leading to mental retardation. Most cases of this disease can be detected through the neonatal screening program. Given the high prevalence of this disease and the implementation of screening programs in recent years in Iran, this study aimed to assess the growth indices of newborns with CH.
Methods: In this retrospective cohort study, 66 newborns with CH detected in the screening program in Shahrekord were selected by a census sampling method. Overall, 125 healthy newborns were also selected as controls by the convenience sampling technique according to the inclusion and exclusion criteria. The height, weight, head circumference, and body mass index (BMI) of the samples were measured and then the mean, median, standard deviation, as well as the 3rd, 15th, 25th, 50th, 75th, 85th, and 97th percentiles in the two groups were determined and compared based on gender and age group.
Results: The height, weight, head circumference, and BMI of the boys, in addition to the head circumference and BMI of the girls, were not significantly different from those of the controls (P>0.05). However, the height and weight of the girls were significantly lower compared to those in the control group, although the difference in the weight was corrected at the age of 9 months.
Conclusion: In general, the growth indices of newborns with CH were lower than those of the controls. This difference was significant only for the weight and height of girls with CH.
Keywords: Congenital hypothyroidism, Growth indices, Newborn Screenin
Effects of dynamic eccentricity in Flux Switching Permanent Magnet machines
This paper investigates the effect of rotating eccentricity fault on a 10/12 Flux Switching Permanent Magnet (FSPM) machine. Main characteristics of the studied machine such as air-gap flux density, magnetic force between rotor and stator and torque profile are calculated by using finite element analysis (FEA) which is the most accurate numerical method. Furthermore, Fourier analysis is performed in order to study the impacts of rotating eccentricity faults on magnetic force and torque profiles. In addition, the results of Fourier analysis of the machine in healthy condition are compared with the machine with 40% rotating eccentricity. This studies shows that the eccentricity has significant effects on FSPM characteristics which shows the importance of investigating the fault. To the best awareness of the authors, the effects of the rotating eccentricity on FSPM machines have not been studied before
Dynamic Assessment of Writing Skill in Advanced EFL Iranian Learners
AbstractDynamic Assessment (hereinafter DA) fundamentally is based on Vygotsky's theory of mediation and ZPD. In contrast to Traditional Assessment (hereinafter TA) which focuses on the product to show the current capability of learners, DA focuses on the process to predict their future achievement. This study intends to investigate the effectiveness of incorporating DA in improving teaching writing at advanced level among Iranian EFL learners. To fulfill this end twenty randomly chosen participants underwent a course of study in advanced writing for the period of two months and in eight sessions. All these participants received the same treatment, however, half of them, in the experimental group, were assessed dynamically and the other half, in the control group, were assessed traditionally. The participants’ essays in both groups were assessed by two distinct raters and their results were statistically analyzed. In order for the study results to be triangulated a questionnaire consisting of three questions was distributed among participants to support the quantitative results in a qualitative and subjective manner. The result of statistical analysis of the T-test which was used to distinguish between the experimental and the control group in addition to the questionnaires showed a significant change in the essays of the participants in the experimental group. The paper concludes with some practical implications for teachers, material developers and syllabus designers
Non-Invasive Measurements and FEM Analyses for Estimating the Rotor Bar-Lamination Contact Resistance
This research work investigates the phenomenon of
interbar currents in induction motors equipped with die-cast alu-
minum cages. Flowing in the lamination and distorting the bar
current distributions, the interbar currents cause additional stray
losses as well as an increase of the joule loss in the cage bars.
The contact resistance between the bars and the rotor lamina-
tions is the key modeling element for a correct prediction of the
interbar currents and the related extra losses. The study presents
a new noninvasive method to obtain a reliable estimation of the
contact resistance. The proposed
hybrid
approach is based on a
mix of experimental data and Finite Element method (FEM)-based
simulation results. A reliable three-dimensional FEM model of a
four-pole 15-kW induction motor with closed rotor slots has been
used to investigate the impact of variable contact resistance on the
interbar currents, rotor joule losses, and the voltage drops along the
bars, opening a new perspective for this complex phenomenon and
its impact on the stray losses. Finally, the proposed methodologies
are critically discussed and the obtained results compared with
other relevant research works
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