scholarly journals Modeling cache performance for embedded systems

2021 ◽  
Vol 10 (5) ◽  
pp. 2910-2920
Author(s):  
Ogechukwu Kingsley Ugwueze ◽  
Chijindu C. V. ◽  
Udeze C. C. ◽  
Ahaneku A. M. ◽  
Eneh N. J. ◽  
...  
Keyword(s):  
Embedded Systems ◽  
Performance Model ◽  
Replacement Policy ◽  
Cumulative Probability ◽  
Estimation Model ◽  
Cache Performance ◽  
The Mean ◽  
Design Options ◽  
Cache Design ◽  
Cache Configurations

This paper presents a cache performance model for embedded systems. The need for efficient cache design in embedded systems has led to the exploration of various methods of design for optimal cache configurations for embedded processor. Better users’ experiences are realized by improving performance parameters of embedded systems. This work presents a cache hit rate estimation model for embedded systems that can be used to explore optimal cache configurations using Bourneli’s binomial cumulative probability based on application of reuse distance profiles. The model presented was evaluated using three mibench benchmarks which are bitcount, basicmath and FFT for 4kb, 8kb, 16kb, 32kb and 64kb sizes of cache under 2-way, 4-ways, 8-ways and 16-ways set associative configurations, all using least recently-used (LRU) replacement policy. The results were compared with the results obtained using sim-cheetah from simplescalar simulators suite. The mean errors for bitcount, basicmath, and FFT benchmarks are 0.0263%, 2.4476%, and 1.9000% respectively. Therefore, the mean error for the three benchmarks is equal to 1.4579%. The margin of errors in the results was below 5% and within the acceptable limits showing that the model can be used to estimate hit rates of cache and to explore cache design options.

On classes of life distributions based on the mean time to failure function

2021 ◽  
Vol 58 (2) ◽  
pp. 289-313
Author(s):  
Ruhul Ali Khan ◽  
Dhrubasish Bhattacharyya ◽  
Murari Mitra
Keyword(s):  
Damage Model ◽  
Replacement Policy ◽  
Time To Failure ◽  
Mean Time To Failure ◽  
Moment Convergence ◽  
Life Distributions ◽  
Cumulative Damage Model ◽  
The Mean ◽  
Age Replacement ◽  
Mean Time

AbstractThe performance and effectiveness of an age replacement policy can be assessed by its mean time to failure (MTTF) function. We develop shock model theory in different scenarios for classes of life distributions based on the MTTF function where the probabilities $\bar{P}_k$ of surviving the first k shocks are assumed to have discrete DMTTF, IMTTF and IDMTTF properties. The cumulative damage model of A-Hameed and Proschan [1] is studied in this context and analogous results are established. Weak convergence and moment convergence issues within the IDMTTF class of life distributions are explored. The preservation of the IDMTTF property under some basic reliability operations is also investigated. Finally we show that the intersection of IDMRL and IDMTTF classes contains the BFR family and establish results outlining the positions of various non-monotonic ageing classes in the hierarchy.

Design of an Intelligent Data Cache with Replacement Policy

2019 ◽  
Vol 10 (2) ◽  
pp. 87-107
Author(s):  
B. Shameedha Begum ◽  
N. Ramasubramanian
Keyword(s):  
Real Time ◽  
Replacement Policy ◽  
Data Cache ◽  
Cache Performance ◽  
Performance Requirements ◽  
Novel Approach ◽  
Reconfigurable Caches ◽  
Real Time Applications ◽  
Hard Real Time ◽  
Replacement Algorithms

Embedded systems are designed for a variety of applications ranging from Hard Real Time applications to mobile computing, which demands various types of cache designs for better performance. Since real-time applications place stringent requirements on performance, the role of the cache subsystem assumes significance. Reconfigurable caches meet performance requirements under this context. Existing reconfigurable caches tend to use associativity and size for maximizing cache performance. This article proposes a novel approach of a reconfigurable and intelligent data cache (L1) based on replacement algorithms. An intelligent embedded data cache and a dynamic reconfigurable intelligent embedded data cache have been implemented using Verilog 2001 and tested for cache performance. Data collected by enabling the cache with two different replacement strategies have shown that the hit rate improves by 40% when compared to LRU and 21% when compared to MRU for sequential applications which will significantly improve performance of embedded real time application.

scholarly journals Estimation of Above-Ground Mangrove Biomass Using Landsat-8 Data- Derived Vegetation Indices: A Case Study in Quang Ninh Province, Vietnam

2021 ◽  
pp. 506-525
Author(s):  
Hai-Hoa Nguyen ◽  
Huy Duc Vu ◽  
Achim Röder
Keyword(s):  
Vegetation Indices ◽  
Landsat 8 ◽  
Mangrove Forests ◽  
Estimation Model ◽  
The Status ◽  
Good Potential ◽  
The Mean ◽  
Accuracy Assessments ◽  
Quang Ninh

This study aimed to map the status of mangrove forests over the coasts of Hai Ha District and Mong Cai City in Quang Ninh Province by using 2019 Landsat-8 imagery. It then developed the AGB estimation model of mangrove forests based on the AGB estimation-derived plots inventory and vegetation indices-derived from Landsat-8 data. As results, there were five land covers identified, including mangrove forests, other vegetation, wetlands, built-up, and water, with the overall accuracy assessments of 80.0% and Kappa coefficient of 0.74. The total extent of mangrove forests was estimated at 4291.2 ha. The best AGB estimation model that was selected to estimate the AGB and AGC of mangrove forests for the whole coasts of Hai Ha District and Mong Cai City is AGB= 30.38 + 911.95*SAVI (R2=0.924, PValue <0.001). The model validation assessment has confirmed that the selected AGB model can be applied to Hai Ha and Mong Cai coasts with the mean difference between AGB observed and AGB predicted at 16.0 %. This satisfactory AGB model also suggests a good potential for AGB and AGC mapping, which offer the carbon trading market in the study site. As the AGB model selected, the total AGB and AGC of mangrove forests were estimated at about 14,600,000 tons and 6,868,076 tons with a range of from 94.0 - 432.0 tons ha-1, from 44.2 - 203.02 tons ha-1, respectively. It also suggests that the newly-developed AGB model of mangrove forests can be used to estimate AGC stocks and carbon sequestration of mangrove forests for C-PFES in over the coasts of Hai Ha District and Mong Cai City, which is a very importantly financial source for mangrove forest managers, in particular for local mangrove protectors.

scholarly journals Geometrical optimization for a photovoltaic installation equipped with flat reflectors based on plane of array estimations

2020 ◽  
Vol 11 ◽  
pp. 1 ◽  
Author(s):  
Christine Abdel Nour ◽  
Anne Migan-Dubois ◽  
Jordi Badosa ◽  
Vincent Bourdin ◽  
Claude Marchand ◽  
...  
Keyword(s):  
Power Production ◽  
Geometrical Parameters ◽  
Estimation Model ◽  
Geometrical Characteristics ◽  
Pv Module ◽  
Geometrical Optimization ◽  
Reflector System ◽  
The Mean ◽  
Experimental Validations ◽  
Geographical Characteristics

In order to design, manage and optimize the performance of a photovoltaic (PV) installation and establish a precise power production estimation, irradiance on the plane of array (POA) in relation with the geometrical characteristics of the PV modules installation occupies a high importance. This study focuses on the development of an estimation model of the POA irradiance for a photovoltaic installation equipped with flat reflectors. The model includes solar irradiance components (global, direct and diffuse), geometrical parameters and geographical characteristics of the PV installation. Experimental validations have been performed with measurements taken at the SIRTA Observatory (48.7°N, 2.2°E) in Palaiseau, France, for the period starting from June 2017 to June 2018. Results show mean absolute errors (relative to the mean) of 6% and 7% for an installation without and with planar reflector. Finally, we present several geometrical optimization strategies of the PV-reflector installation relying on two major variables: the reflector's length (LR) compared to the length of the PV module (LPV) and the tilt angle adjustment frequency (monthly, seasonally, fixed) of the system (for both PV and the reflectors). The objective of such optimization is to discuss about a reasonable configuration to achieve a maximum POA irradiance. Results show that the length of the mirrors highly affects the efficiency and performances of the PV-Reflector system and the annual gain increased from 8.5% to 28.7% when going from LR = LPV/2 to LR = 2 × LPV compared to a monthly-optimized installation without mirrors. As for the adjustment frequency, we show that a monthly-varied architecture is the most advantageous option with a 28.2 and 31.6% increasing in annual gain compared to a seasonal varied or fixed ones, respectively.

Micropulsed diode laser cyclophotocoagulation in recurrent pediatric glaucoma

2019 ◽  
Vol 30 (5) ◽  
pp. 1149-1155 ◽  
Author(s):  
Eman M Elhefney ◽  
Tharwat H Mokbel ◽  
Sherein M Hagras ◽  
Ahmed A AlNagdy ◽  
Adel A Ellayeh ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Diode Laser ◽  
Congenital Glaucoma ◽  
Secondary Outcome ◽  
Cumulative Probability ◽  
Pediatric Glaucoma ◽  
Significant Difference ◽  
The Mean ◽  
Diode Laser Cyclophotocoagulation

Purpose: To evaluate the intermediate-term efficacy and safety of micropulsed diode laser cyclophotocoagulation in recurrent pediatric glaucoma. Patients and Methods: A prospective interventional study included children <16 years old diagnosed with recurrent glaucoma, attending Mansoura University, during the period from July 2017 to November 2017. Micropulsed diode laser sessions were performed in all the cases. The main outcome was the intraocular pressure reduction with monitoring of complications as secondary outcome. The mean follow-up period was 15.08 ± 1.1 (mean: 12–16) months. Results: A total of 36 eyes of 29 patients were included (62% males) with median age of 24 months. Primary congenital glaucoma represented 47.2% of the initial diagnoses. At the 15th month, the mean intraocular pressure dropped significantly from 37.5 ± 11.3 mmHg at baseline to 20.03 ± 2.7 mmHg (p < 0.001) with 37.15% reduction. The mean number of glaucoma medications decreased significantly from 2.6 ± 0.5 pretreatment to 1.7 ± 0.6 at the 15th month (p < 0.001). A total of 24 eyes (66.7%) required second session of treatment with mean number of 1.7 ± 0.5 sessions per eye. The cumulative probability of qualified success was 69.4%, 58.3%, 52.8%, 47.2%, and 41.7% at 1, 3, 6, 12, and 15 months after treatment. Qualified success was achieved in 61% at 15 months without statistically significant difference between the initial diagnoses (p = 0.61). None of the eyes developed any major ocular complications throughout the follow-up period. Conclusion: Micropulsed diode laser was proved to be a safe approach with relative effectiveness in controlling intraocular pressure in children with recurrent glaucoma.

Long-term effect of natalizumab in patients with RRMS: TYSTEN cohort

2020 ◽  
pp. 135245852093623
Author(s):  
Kévin Bigaut ◽  
Thibaut Fabacher ◽  
Laurent Kremer ◽  
Jean-Claude Ongagna ◽  
Arnaud Kwiatkowski ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Disease Activity ◽  
Predictive Factors ◽  
Term Effect ◽  
Cumulative Probability ◽  
Secondary Progressive ◽  
Long Term Effect ◽  
The Mean ◽  
Poor Outcomes

Background: Data are needed on long-term effect of natalizumab (NTZ) in relapsing-remitting multiple sclerosis (RRMS). Objectives: To evaluate the time of onset of secondary progressive phase in patients with an RRMS treated with NTZ and to investigate predictive factors. Methods: TYSTEN is an observational study. Patients starting NTZ between 2007 and 2012 were included and followed up until October 2018. Relapses, Expanded Disability Status Scale (EDSS) scores, and results of brain magnetic resonance imaging (MRI) were collected each year. Data were used to estimate the cumulative probability of several poor outcomes such as secondary progressive multiple sclerosis (SPMS) conversion, EDSS worsening, EDSS 4.0, and EDSS 6.0. Results: 770 patients were included. The mean follow-up duration was 97 months and the mean time exposure to NTZ was 66 months. At 10 years, the cumulative probability of SPMS was 27.7%. Predictive factors for poor outcomes were a ⩾1-point increase in EDSS score from baseline, new T2 lesion or T1 gadolinium-enhancing lesion, the occurrence of relapse at 1 or 2 years and No Evidence of Disease Activity (NEDA-3; no relapse, no new T2 or T1 gadolinium-enhancing lesions, no progression) was a protective factor. Conclusion: In our cohort of patients treated with NTZ, poor outcomes were infrequent and are driven by disease activity.

scholarly journals Combined Technique for the Application of Micropulse Cyclophotocoagulation in Patients with Uncontrolled Glaucoma: Cyclo Mix

2020 ◽  
Vol 14 (3) ◽  
pp. 93-97
Author(s):  
Loayza-Gamboa Waldo ◽  
Herrera-Quiroz Julio ◽  
Chávez-Vallejos Jennifer ◽  
Valderrama-Albino Vanessa ◽  
Córdova-Crisanto Luis ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Open Angle Glaucoma ◽  
Wave Mode ◽  
Cumulative Probability ◽  
Eye Drops ◽  
Change In The Mean ◽  
Surgical Failure ◽  
Continuous Wave Mode ◽  
The Mean ◽  
Combined Technique

ABSTRACT Purpose To describe the outcomes of a combined technique (Cyclo Mix) in uncontrolled glaucoma cases. Materials and methods Retrospective study. The Supra 810 nm subliminal laser (Quantel Medical, Cournon d'Auvergne, France) was used. A combined technique was performed using the subliminal mode (Subcyclo) in one hemifield (power of 2,000 mW, a duty cycle of 35%, and 80–150 seconds), and the continuous wave mode (Thermo Cyclo) on the other hemifield (power of 1,000 mW, exposure time of 2 seconds per spot). The primary endpoint was the probability of surgical failure. Mean intraocular pressure (IOP) change, best-corrected visual acuity (BCVA), number of glaucoma eye drops, and complications at 6 months postoperatively were secondary outcomes. Results Twenty-three eyes from 13 patients were included. Mean age was 61.4 ± 16.7 (range: 18–78 years), and 69% were female, with a baseline IOP of 20.3 ± 5.9 (range: 13–38 mm Hg). The cumulative probability of failure was 18 and 22% on days 90 and 180, respectively. Mean IOP reduction was −25.6 ± 20.9% at 6 months. The number of glaucoma eye drops was reduced to 1.2 ± 1 (p = 0.0024) at 6 months. No statistically significant change in the mean BCVA compared with baseline at 6 months was found (p = 0.84), and no severe complications were reported. Conclusion Cyclo Mix seems to be a safe therapy that effectively reduces the IOP and glaucoma medications in eyes with uncontrolled open-angle glaucoma for up to 6 months. How to cite this article Waldo L-G, Julio H-Q, Jennifer C-V, et al. Combined Technique for the Application of Micropulse Cyclophotocoagulation in Patients with Uncontrolled Glaucoma: Cyclo Mix. J Curr Glaucoma Pract 2020;14(3):93–97.

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