Papers by Mohammad Dashti
Jorjani biomedicine journal, Oct 10, 2016
Background & Objective: Cardiac massage is the first and most important step during Cardio Pulmon... more Background & Objective: Cardiac massage is the first and most important step during Cardio Pulmonary Resuscitation (CPR). Effective massage restores blood flow to the brain and heart and plays a remarkable role in a successful CPR. Exhaustion of treatment team during resuscitation is one of the factors which may lead to reduced quality of resuscitation massages or failure in some cases. The aim of this study was to design, construct and evaluate a new cardiac massage facilitator to improve the quality of CPR in adult patients. Methods: In this study, the massage facilitator was designed and registered as a glove which was worn by rescuers during cardiac massage (number of invention: 80797). A load cell sensor was placed under the surface of the glove and the facilitator could be displayed number and depth of massage in centimeters. In order to evaluate the efficiency of the designed system, an experimental study was conducted among 30 emergency students. All statistical analyses were performed by SPSS 19 software using Pearson correlation and independent sample t-test. P-values lower than 0.05 were considered to be significant. Results: The mean age of all participants was 23.41±2.02 years, the mean height was 175±4.43 centimeters and the mean weight was 65.45±5.02 kilograms. The instrument validity was evaluated using standard validation method of concurrent validity. Our findings revealed a significant correlation between the cardiac massage facilitator and Sim Pad system (more than 0.9). Accordingly, the validity of cardiac massage facilitator was confirmed. While assessing the efficient massage criteria during cardiac massage facilitator utilization, the massage possessed suitable depth (less than 5 cm) in 98% of participants. The numbers of massages were at least 100 massages per minute in 93% of participants. Conclusion: The results showed that designed system could be used as an effective tool to improve quality of cardiac massage in CPR.
DOAJ (DOAJ: Directory of Open Access Journals), Feb 1, 2015
Introduction and Aims Evidence based medicine aids the delivery of effective service to patients,... more Introduction and Aims Evidence based medicine aids the delivery of effective service to patients, diagnosing and treating. According to Clinical guidelines of evidence-based medicine, it's possible to change clinical decision, improve treatment and promote the patients´ health. The purpose of this study is to survey knowledge, attitudes and performance about evidence-based medicine among physicians. Materials and Methods All of the physicians in educational hospitals of medical faculty of Neyshabur, were entered in this cross-descriptive study by convenience sampling method. The questionnaire included demographic information and also information about knowledge, attitudes and obstacles of evidence-based medicine. Data were analyzed by SPSS v.16 software and descriptive statistics. Results Results showed that 88 % of physicians had little familiarity with evidence-based medicine and its resources. 47.8 % of them employed evidence-based medicine in their treatment decisions and 60.4 % knew the significance of evidence-based medicine for medical teams. Overloud of information were reported by 55.1 % of participants as preventive factor in use of evidence-based medicine. Conclusion According to low level of knowledge and performance in evidence-based medicine among physicians, promoting awareness and practice is needed.
International Journal of Circuit Theory and Applications, Sep 21, 2018
An area-efficient amplifier topology is presented for three-stage amplifiers driving ultralarge l... more An area-efficient amplifier topology is presented for three-stage amplifiers driving ultralarge load capacitor with reduced power consumption. It contains two high-speed ac feedback loops made from embedded current buffers and smallsize compensation capacitors, which pushes the nondominant complex poles to very high frequencies. To further improve the stability, a local impedance damping block is embedded. At the higher frequencies, it suppresses the high resistive property at the second-stage output, thereby increasing the damping factor of the complex poles and improving the overall gain margin. For identical bandwidth, the overall silicon area of the on-chip compensation capacitor is therefore decreased, leading to enhanced small-signal and large-signal performance metrics. Coined dual loop cascode-Miller compensation with damping factor control unit, the effectiveness of the proposed approach is investigated through simulation results in 90-nm complementary metal-oxide-semiconductor (CMOS) technology. An implementation based on the proposed technique consumes a quiescent current of 17 μA from a 1.2 V voltage supply. For a load capacitance equal to 560 pF, it achieves a gain-bandwidth frequency of 4.34 MHz, an average slew-rate of 1.72 V/μs, and an average settling time of 0.52 μs, when the overall compensation capacitance is set to 1.55 pF. The proposed design can supply the load capacitors up to 35 nF.
Journal of Circuits, Systems, and Computers, Aug 1, 2017
Room-temperature analog-to-digital converters (ADCs) based on nanoscale silicon (Si) quantum dot ... more Room-temperature analog-to-digital converters (ADCs) based on nanoscale silicon (Si) quantum dot (QD)-based single-electron transistors (SETs) can be very attractive for high-speed processors embedded in future generation nanosystems. This paper focuses on the design and modeling of advanced single-electron converters suited for operation at room temperature. In contrast to conventional SETs with metallic QD, the use of sub-10-nm Si QD results in stable operation at room temperature, as the observable Coulomb blockade regime covers effectively the higher temperature range. Si QD-based SETs are also fully compatible with advanced CMOS technology and they can be manufactured using routine nanofabrication steps. At first, we present the principles of operation of Si SETs used for room-temperature operation. Possible flash-type ADC architectures are then investigated and the design considerations of possible Coulomb oscillation regimes are addressed. A modified design procedure is then introduced for [Formula: see text]-bit SET-based ADCs, and validated through simulation of a 3-bit ADC with a sampling frequency of 5 GS/s. The ADC core is comprised from a capacitive signal divider followed by three periodic symmetric functions (PSFs). Simulation results demonstrate the stability of output signals at the room-temperature range.
Otorhinolaryngology-Head and Neck Surgery, 2018
Swallowing disorders can occur in all age groups, resulting from congenital abnormalities, struct... more Swallowing disorders can occur in all age groups, resulting from congenital abnormalities, structural damage, and/or medical conditions. Oropharyngeal dysphagia arises from abnormalities of muscles, nerves or structures of the oral cavity, pharynx, and upper esophageal sphincter. If left untreated, swallowing disorders can potentially cause aspiration pneumonia, malnutrition, or dehydration. Central to providing comprehensive interdisciplinary care are the head and neck surgeon, laryngologist, and speech-language pathologist. Routine assessment, long-term follow-up, and regular communication and coordination among these specialists help maximize quality of life in this challenging patient population.
Analysis of conjugate natural convection with surface radiation in a two-dimensional enclosure is... more Analysis of conjugate natural convection with surface radiation in a two-dimensional enclosure is carried out in order to search the optimal location of the heat source with entropy generation minimization (EGM) approach and conventional heat transfer parameters. The air as an incompressible fluid and transparent media is considered the fluid filling the enclosure with the steady and laminar regime. The enclosure internal surfaces are also gray, opaque and diffuse. The governing equations with stream function and vorticity formulation are solved using finite difference approach. Results include the effect of Rayleigh number and emissivity on the dimensionless average rate of entropy generation and its optimum location. The optimum location search with conventional heat transfer parameters including maximum temperature and Nusselt numbers are also examined.
ArXiv, 2020
Systems integrating heterogeneous processors with unified memory provide seamless integration amo... more Systems integrating heterogeneous processors with unified memory provide seamless integration among these processors with minimal development complexity. These systems integrate accelerators such as GPUs on the same die with CPU cores to accommodate running parallel applications with varying levels of parallelism. Such integration is becoming very common on modern chip architectures, and it places a burden (or opportunity) on application and system programmers to utilize the full potential of such integrated chips. In this paper we evaluate whether we can obtain any performance benefits from running garbage collection on integrated GPU systems, and discuss how difficult it would be to realize these gains for the programmer. Proliferation of garbage-collected languages running on a variety of platforms from handheld mobile devices to data centers makes garbage collection an interesting target to examine on such platforms and can offer valuable lessons for other applications. We prese...
Background & Objective: Cardiac massage is the first and most important step during Cardio Pulmon... more Background & Objective: Cardiac massage is the first and most important step during Cardio Pulmonary Resuscitation (CPR). Effective massage restores blood flow to the brain and heart and plays a remarkable role in a successful CPR. Exhaustion of treatment team during resuscitation is one of the factors which may lead to reduced quality of resuscitation massages or failure in some cases. The aim of this study was to design, construct and evaluate a new cardiac massage facilitator to improve the quality of CPR in adult patients. Methods: In this study, the massage facilitator was designed and registered as a glove which was worn by rescuers during cardiac massage (number of invention: 80797). A load cell sensor was placed under the surface of the glove and the facilitator could be displayed number and depth of massage in centimeters. In order to evaluate the efficiency of the designed system, an experimental study was conducted among 30 emergency students. All statistical analyses were performed by SPSS 19 software using Pearson correlation and independent sample t-test. P-values lower than 0.05 were considered to be significant. Results: The mean age of all participants was 23.41±2.02 years, the mean height was 175±4.43 centimeters and the mean weight was 65.45±5.02 kilograms. The instrument validity was evaluated using standard validation method of concurrent validity. Our findings revealed a significant correlation between the cardiac massage facilitator and Sim Pad system (more than 0.9). Accordingly, the validity of cardiac massage facilitator was confirmed. While assessing the efficient massage criteria during cardiac massage facilitator utilization, the massage possessed suitable depth (less than 5 cm) in 98% of participants. The numbers of massages were at least 100 massages per minute in 93% of participants. Conclusion: The results showed that designed system could be used as an effective tool to improve quality of cardiac massage in CPR.
Queue, 2015
Modern server-class systems are typically built as several multicore chips put together in a sing... more Modern server-class systems are typically built as several multicore chips put together in a single system. Each chip has a local DRAM (dynamic random-access memory) module; together they are referred to as a node. Nodes are connected via a high-speed interconnect, and the system is fully coherent. This means that, transparently to the programmer, a core can issue requests to its node’s local memory as well as to the memories of other nodes. The key distinction is that remote requests will take longer, because they are subject to longer wire delays and may have to jump several hops as they traverse the interconnect. The latency of memory-access times is hence non-uniform, because it depends on where the request originates and where it is destined to go. Such systems are referred to as NUMA (non-uniform memory access).
BackgroundIn this study, we aimed to evaluate the impact of the COVID-19 epidemic on the workload... more BackgroundIn this study, we aimed to evaluate the impact of the COVID-19 epidemic on the workload and mental health of Iranian medical staffs using the General Health Questionnaire (GHQ-12) and NASA-TLX Questionnaire between March and April 2020, respectively.MethodsThe present cross-sectional study was conducted from March 5th to April 5th, 2020. Three online questionnaires (NASA-TLX, GHQ-12, and demographic) were distributed. Data were entered into software SPSS (Version 23) and T-test, ANOVA, Regression methods were used for data analysis.ResultsHealth workers who encountered COVID- 19 patients, were subjected to more task load compared to those who had no contact with COVID- 19 patients at the workplace (p<0.001). In terms of the subscale score of NASA-TLX, nurses had more scores in mental pressure, physical pressure, time pressure(temporal), and frustration compared to the other jobs (p<0.05). Moreover, nurses had significantly more workload compared to the other jobs.Con...
Background Workload and mental health problems of health care workers (HCWs) in the COVID-19 pand... more Background Workload and mental health problems of health care workers (HCWs) in the COVID-19 pandemic is a concern. These problems increase medical error and mortality of patient and can reduce performance HCWs. Methods We studied 495 HCWs in Iran between March and April 2020. Three online questionnaires (NASA-TLX, GHQ-12, and demographic) were distributed to them via social networks. Data were entered into software SPSS v.25 and T-test, ANOVA, Regression methods were used for data analysis. Results Task load and mental disorder were significantly higher in HCWs who encountered COVID- 19 patients (p < 0.001). Among HCWs, nurses had the highest workload (71 ± 16.13, p < 0.001). Females had significantly higher GHQ scores compared to males (6.54 ± 1.84 vs. 5.90 ± 2.21, p = 0.003). Regarding the ward of work, health workers in the Corona part had more total task load scores compared to workers in health centers (71.56 ± 17.40 vs. 63.94 ± 17.36, p = 0.003). Total GHQ score had sig...
Surgery and Rehabilitation, 2017
Journal of Dentistry Open Access, 2020
The decision to save or extract a natural tooth which has been compromised is one of the dilemmas... more The decision to save or extract a natural tooth which has been compromised is one of the dilemmas of dental practitioners, as well as the patients. Although there was a considerable effort to save the natural teeth in the past, with the introduction of osseointegrated implants, there is a tendency to extract the compromised teeth and replace them with implant-supported prosthesis. In this article, this important clinical decision is investigated, and a successful restoration of a traumatized anterior tooth is presented.
ACM SIGPLAN Notices, 2017
Heterogeneous systems that integrate a multicore CPU and a GPU on the same die are ubiquitous. On... more Heterogeneous systems that integrate a multicore CPU and a GPU on the same die are ubiquitous. On these systems, both the CPU and GPU share the same physical memory as opposed to using separate memory dies. Although integration eliminates the need to copy data between the CPU and the GPU, arranging transparent memory sharing between the two devices can carry large overheads. Memory on CPU/GPU systems is typically managed by a software framework such as OpenCL or CUDA, which includes a runtime library, and communicates with a GPU driver. These frameworks offer a range of memory management methods that vary in ease of use, consistency guarantees and performance. In this study, we analyze some of the common memory management methods of the most widely used software frameworks for heterogeneous systems: CUDA, OpenCL 1.2, OpenCL 2.0, and HSA, on NVIDIA and AMD hardware. We focus on performance/functionality trade-offs, with the goal of exposing their performance impact and simplifying th...
Heat Transfer—Asian Research, 2019
Analysis of combined natural convection with surface radiation in a two‐dimensional enclosure is ... more Analysis of combined natural convection with surface radiation in a two‐dimensional enclosure is carried out. To search the optimal location of the heat source, the entropy generation minimization approach and conventional heat transfer parameters are used and compared. Air is considered as an incompressible fluid and transparent media filling the enclosure with a steady and laminar regime. The enclosure internal surfaces are also gray, opaque, and diffused. The governing equations are solved using the finite difference approach. The results show that with increase in emissivity, entropy generation decreases, and as the Rayleigh number increases, the rate of entropy generation increases. Furthermore, optimum design with the maximum dimensionless temperature and convective Nusselt number confirms the applicability of the second law for optimal design.
The Journal of Contemporary Dental Practice, 2009
AimOcclusal disharmony is frequently observed among edentulous patients. With the side effects of... more AimOcclusal disharmony is frequently observed among edentulous patients. With the side effects of occlusal disharmony in mind, the goal of this research was to investigate the prevalence of occlusal disharmony in inserted complete dentures and its associated causes.Methods and MaterialsThis cross-sectional study was conducted on 107 selected patients. Factors such as age, gender, ridge relationship on the articulator, occlusal scheme, and the performance of a clinical remount from patients’ treatment records were investigated. The presence and/or status of any occlusal disharmony was determined by a calibrated prosthodontist extraorally and qualitatively. Occlusal disharmony is defined as the absence of simultaneous bilateral contacts between the opposing posterior teeth in centric relation. The prevalence of occlusal disharmony was determined and the roles of the aforementioned factors were studied and analyzed using a Chisquare analysis. The results were considered significant at ...
Communications of the ACM, 2015
Optimizing NUMA systems applications with Carrefour.
Proceedings of the 19th international conference on Parallel architectures and compilation techniques, 2010
On multicore systems, contention for shared resources occurs when memory-intensive threads are co... more On multicore systems, contention for shared resources occurs when memory-intensive threads are co-scheduled on cores that share parts of the memory hierarchy, such as last-level caches and memory controllers. Previous work investigated how contention could be addressed via scheduling. A contention-aware scheduler separates competing threads onto separate memory hierarchy domains to eliminate resource sharing and, as a consequence, to mitigate contention. However, all previous work on contention-aware scheduling assumed that the underlying system is UMA (uniform memory access latencies, single memory controller). Modern multicore systems, however, are NUMA, which means that they feature non-uniform memory access latencies and multiple memory controllers. We discovered that state-of-the-art contention management algorithms fail to be effective on NUMA systems and may even hurt performance relative to a default OS scheduler. In this paper we investigate the causes for this behavior and design the first contention-aware algorithm for NUMA systems.
Quintessence international (Berlin, Germany : 1985), 2013
Two commonly used attachment systems for implant-retained overdentures are bar and ball systems. ... more Two commonly used attachment systems for implant-retained overdentures are bar and ball systems. The aim of this study was to compare these two types of attachments on the basis of the stresses introduced to the mandibular posterior residual ridge by an overdenture retained by two implants. A basic model was generated from the data provided by a CT scan of a patient's mandible, the diagnostic casts, and the existing overdenture. Two root-form implants were placed in the anterior mandible. Models were used to simulate two situations: The first model represented an edentulous mandible supporting an overdenture retained by two implants connected with a bar and plastic clip system, and in the second model two ball attachments with nylon caps were used as the retention mechanism. A 35 N vertical load was introduced to the first molar region of each group to simulate the occlusal forces of the maxillary complete denture. The stresses in the mandibular residual ridges under the first m...
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Papers by Mohammad Dashti