Killing Processes or Killing Flash? Escaping from the Dilemma Using Lightweight, Compression-Aware Swap for Mobile Devices

2021 ◽  
Vol 20 (5s) ◽  
pp. 1-24
Author(s):  
Yong-Xuan Wang ◽  
Chung-Hsuan Tsai ◽  
Li-Pin Chang
Keyword(s):  
User Experience ◽  
Memory Management ◽  
Essential Feature ◽  
Replacement Policy ◽  
Flash Storage ◽  
Storage Devices ◽  
Android Apps ◽  
The Mean ◽  
Time And Energy ◽  
Mean Time

Android apps become increasingly memory-demanding as software vendors add more and more new features to their apps. In the mean time, Android users often launch multiple apps and conveniently switch back and forth among the apps. Although running multiple apps imposes a high pressure on memory management, virtual-memory swap, an essential feature to improve the degree of multitasking, is disabled in fear of premature retirement of flash-based storage devices. Instead, Android employs a termination-based, process-level memory reclaiming method. We observed that process killing is, unfortunately, not effective in memory reclaiming and is highly negative to user experience. In this study, we advocate re-thinking using swap in Android for improved user experience with managed write stress on flash storage. Based on a series of empirical analyses of swap activities, we propose an enhanced page replacement policy and a page-compressing frontswap module. The proposed page replacement policy jointly considers page activeness and compressibility to boost the compression ratio of swap writes. A sampled-based method for page compressibility prediction is introduced so that decisions on page replacement can be made without compressing every page. We also design a frontswap module that strategically organizes compressed pages in the swap space for reducing the overhead of swap I/O operations. Experimental results showed that compared with process killing, our method improved the app launching time and energy consumption by 58% and 19%, respectively; compared with the original swap, our approach reduced the swap write stress by 65%.

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.

Log-buffer aware cache replacement policy for flash storage devices

2017 ◽  
Vol 63 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Usman Anwar ◽  
Joon-Young Paik ◽  
Rize Jin ◽  
Tae-Sun Chung
Keyword(s):  
Replacement Policy ◽  
Cache Replacement ◽  
Flash Storage ◽  
Storage Devices ◽  
Cache Replacement Policy

New nonparametric classes of distributions in terms of mean time to failure in age replacement

2018 ◽  
Vol 55 (4) ◽  
pp. 1238-1248 ◽  
Author(s):  
Muhyiddin Izadi ◽  
Maryam Sharafi ◽  
Baha-Eldin Khaledi
Keyword(s):  
Replacement Policy ◽  
Time To Failure ◽  
Mean Time To Failure ◽  
Lifetime Distributions ◽  
The Mean ◽  
Age Replacement ◽  
Mean Time

Abstract The mean time to failure (MTTF) function in age replacement is used to evaluate the performance and effectiveness of the age replacement policy. In this paper, based on the MTTF function, we introduce two new nonparametric classes of lifetime distributions with nonmonotonic mean time to failure in age replacement; increasing then decreasing MTTF (IDMTTF) and decreasing then increasing MTTF (DIMTTF). The implications between these classes of distributions and some existing classes of nonmonotonic ageing classes are studied. The characterizations of IDMTTF and DIMTTF in terms of the scaled total time on test transform are also obtained.

scholarly journals User Experience of a Chatbot Questionnaire Versus a Regular Computer Questionnaire: Prospective Comparative Study (Preprint)

2020 ◽  
Author(s):  
Mariska E te Pas ◽  
Werner G M M Rutten ◽  
R Arthur Bouwman ◽  
Marc P Buise
Keyword(s):  
User Experience ◽  
Response Rates ◽  
Time To Completion ◽  
Adequate Response ◽  
Prospective Comparative Study ◽  
The Mean ◽  
Survey Designs ◽  
Mean Time ◽  
Experience Questionnaire

BACKGROUND Respondent engagement of questionnaires in health care is fundamental to ensure adequate response rates for the evaluation of services and quality of care. Conventional survey designs are often perceived as dull and unengaging, resulting in negative respondent behavior. It is necessary to make completing a questionnaire attractive and motivating. OBJECTIVE The aim of this study is to compare the user experience of a chatbot questionnaire, which mimics intelligent conversation, with a regular computer questionnaire. METHODS The research took place at the preoperative outpatient clinic. Patients completed both the standard computer questionnaire and the new chatbot questionnaire. Afterward, patients gave their feedback on both questionnaires by the User Experience Questionnaire, which consists of 26 terms to score. RESULTS The mean age of the 40 included patients (25 [63%] women) was 49 (SD 18-79) years; 46.73% (486/1040) of all terms were scored positive for the chatbot. Patients preferred the computer for 7.98% (83/1040) of the terms and for 47.88% (498/1040) of the terms there were no differences. Completion (mean time) of the computer questionnaire took 9.00 minutes by men (SD 2.72) and 7.72 minutes by women (SD 2.60; <i>P</i>=.148). For the chatbot, completion by men took 8.33 minutes (SD 2.99) and by women 7.36 minutes (SD 2.61; <i>P</i>=.287). CONCLUSIONS Patients preferred the chatbot questionnaire over the computer questionnaire. Time to completion of both questionnaires did not differ, though the chatbot questionnaire on a tablet felt more rapid compared to the computer questionnaire. This is an important finding because it could lead to higher response rates and to qualitatively better responses in future questionnaires.

scholarly journals User Experience of a Chatbot Questionnaire Versus a Regular Computer Questionnaire: Prospective Comparative Study

10.2196/21982 ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. e21982
Author(s):  
Mariska E te Pas ◽  
Werner G M M Rutten ◽  
R Arthur Bouwman ◽  
Marc P Buise
Keyword(s):  
User Experience ◽  
Response Rates ◽  
Time To Completion ◽  
Adequate Response ◽  
Prospective Comparative Study ◽  
The Mean ◽  
Survey Designs ◽  
Mean Time ◽  
Experience Questionnaire

Background Respondent engagement of questionnaires in health care is fundamental to ensure adequate response rates for the evaluation of services and quality of care. Conventional survey designs are often perceived as dull and unengaging, resulting in negative respondent behavior. It is necessary to make completing a questionnaire attractive and motivating. Objective The aim of this study is to compare the user experience of a chatbot questionnaire, which mimics intelligent conversation, with a regular computer questionnaire. Methods The research took place at the preoperative outpatient clinic. Patients completed both the standard computer questionnaire and the new chatbot questionnaire. Afterward, patients gave their feedback on both questionnaires by the User Experience Questionnaire, which consists of 26 terms to score. Results The mean age of the 40 included patients (25 [63%] women) was 49 (SD 18-79) years; 46.73% (486/1040) of all terms were scored positive for the chatbot. Patients preferred the computer for 7.98% (83/1040) of the terms and for 47.88% (498/1040) of the terms there were no differences. Completion (mean time) of the computer questionnaire took 9.00 minutes by men (SD 2.72) and 7.72 minutes by women (SD 2.60; P=.148). For the chatbot, completion by men took 8.33 minutes (SD 2.99) and by women 7.36 minutes (SD 2.61; P=.287). Conclusions Patients preferred the chatbot questionnaire over the computer questionnaire. Time to completion of both questionnaires did not differ, though the chatbot questionnaire on a tablet felt more rapid compared to the computer questionnaire. This is an important finding because it could lead to higher response rates and to qualitatively better responses in future questionnaires.

Predicting Daily Maintenance Dose of Fluindione, an Oral Anticoagulant Drug

1996 ◽  
Vol 75 (05) ◽  
pp. 731-733 ◽  
Author(s):  
V Cazaux ◽  
B Gauthier ◽  
A Elias ◽  
D Lefebvre ◽  
J Tredez ◽  
...  
Keyword(s):  
Effective Dose ◽  
Maintenance Dose ◽  
Successive Approximations ◽  
Hemorrhagic Complication ◽  
Simple Method ◽  
Individual Variations ◽  
Anticoagulant Drug ◽  
The Mean ◽  
Mean Time ◽  
Daily Maintenance Dose

SummaryDue to large inter-individual variations, the dose of vitamin K antagonist required to target the desired hypocoagulability is hardly predictible for a given patient, and the time needed to reach therapeutic equilibrium may be excessively long. This work reports on a simple method for predicting the daily maintenance dose of fluindione after the third intake. In a first step, 37 patients were delivered 20 mg of fluindione once a day, at 6 p.m. for 3 consecutive days. On the morning of the 4th day an INR was performed. During the following days the dose was adjusted to target an INR between 2 and 3. There was a good correlation (r = 0.83, p<0.001) between the INR performed on the morning of day 4 and the daily maintenance dose determined later by successive approximations. This allowed us to write a decisional algorithm to predict the effective maintenance dose of fluindione from the INR performed on day 4. The usefulness and the safety of this approach was tested in a second prospective study on 46 patients receiving fluindione according to the same initial scheme. The predicted dose was compared to the effective dose soon after having reached the equilibrium, then 30 and 90 days after. To within 5 mg (one quarter of a tablet), the predicted dose was the effective dose in 98%, 86% and 81% of the patients at the 3 times respectively. The mean time needed to reach the therapeutic equilibrium was reduced from 13 days in the first study to 6 days in the second study. No hemorrhagic complication occurred. Thus the strategy formerly developed to predict the daily maintenance dose of warfarin from the prothrombin time ratio or the thrombotest performed 3 days after starting the treatment may also be applied to fluindione and the INR measurement.

Retrospective analysis of mortality within 30 days of systemic anticancer therapy and comparison with a previous audit at an Australian Regional Cancer Centre

2021 ◽  
pp. 107815522110160
Author(s):  
Bernadatte Zimbwa ◽  
Peter J Gilbar ◽  
Mark R Davis ◽  
Srinivas Kondalsamy-Chennakesavan
Keyword(s):  
Checkpoint Inhibitors ◽  
Anticancer Therapy ◽  
Mortality Rates ◽  
Feedback Process ◽  
Time To Death ◽  
Cancer Centre ◽  
Haematology Patients ◽  
The Mean ◽  
Regional Cancer Centre ◽  
Mean Time

Purpose To retrospectively determine the rate of death occurring within 14 and 30 days of systemic anticancer therapy (SACT), compare this against a previous audit and benchmark results against other cancer centres. Secondly, to determine if the introduction of immune checkpoint inhibitors (ICI), not available at the time of the initial audit, impacted mortality rates. Method All adult solid tumour and haematology patients receiving SACT at an Australian Regional Cancer Centre (RCC) between January 2016 and July 2020 were included. Results Over a 55-month period, 1709 patients received SACT. Patients dying within 14 and 30 days of SACT were 3.3% and 7.0% respectively and is slightly higher than our previous study which was 1.89% and 5.6%. Mean time to death was 15.5 days. Males accounted for 63.9% of patients and the mean age was 66.8 years. 46.2% of the 119 patients dying in the 30 days post SACT started a new line of treatment during that time. Of 98 patients receiving ICI, 22.5% died within 30 days of commencement. Disease progression was the most common cause of death (79%). The most common place of death was the RCC (38.7%). Conclusion The rate of death observed in our re-audit compares favourably with our previous audit and is still at the lower end of that seen in published studies in Australia and internationally. Cases of patients dying within 30 days of SACT should be regularly reviewed to maintain awareness of this benchmark of quality assurance and provide a feedback process for clinicians.

Vitamin D Level Stability in Dystrophinopathy Patients on Vitamin D Supplementation

2021 ◽  
pp. 1-7
Author(s):  
Naomi Vather-Wu ◽  
Matthew D. Krasowski ◽  
Katherine D. Mathews ◽  
Amal Shibli-Rahhal
Keyword(s):  
Vitamin D ◽  
Retrospective Cohort ◽  
Vitamin D Supplementation ◽  
Hydroxyvitamin D ◽  
Frequent Monitoring ◽  
25 Hydroxyvitamin D ◽  
The Mean ◽  
Stable Maintenance ◽  
Mean Time

Background: Expert guidelines recommend annual monitoring of 25-hydroxyvitamin D (25-OHD) and maintaining 25-OHD ≥30 ng/ml in patients with dystrophinopathies. Objective: We hypothesized that 25-OHD remains stable and requires less frequent monitoring in patients taking stable maintenance doses of vitamin D. Methods: We performed a retrospective cohort study, using the electronic health record to identify 26 patients with dystrophinopathies with a baseline 25-OHD ≥30 ng/mL and at least one additional 25-OHD measurement. These patients had received a stable dose of vitamin D for ≥3 months prior to their baseline 25-OHD measurement and throughout follow-up. The main outcome measured was the mean duration time the subjects spent with a 25-OHD ≥30 ng/mL. Results: Only 19% of patients dropped their 25-OHD to <  30 ng/ml, with a mean time to drop of 33 months and a median nadir 25-OHD of 28 ng/mL. Conclusions: These results suggest that measurement of 25-OHD every 2–2.5 years may be sufficient in patients with a baseline 25-OHD ≥30 ng/mL and who are on a stable maintenance dose of vitamin D. Other patients may require more frequent assessments.

scholarly journals Surveillance System in Smart Cities: A Dependability Evaluation Based on Stochastic Models

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 876
Author(s):  
Igor Gonçalves ◽  
Laécio Rodrigues ◽  
Francisco Airton Silva ◽  
Tuan Anh Nguyen ◽  
Dugki Min ◽  
...  
Keyword(s):  
Surveillance System ◽  
Smart Cities ◽  
Heterogeneous Data ◽  
Time To Failure ◽  
Video Streams ◽  
Dependability Evaluation ◽  
The Mean ◽  
Mean Time ◽  
The Internet Of Things

Surveillance monitoring systems are highly necessary, aiming to prevent many social problems in smart cities. The internet of things (IoT) nowadays offers a variety of technologies to capture and process massive and heterogeneous data. Due to the fact that (i) advanced analyses of video streams are performed on powerful recording devices; while (ii) surveillance monitoring services require high availability levels in the way that the service must remain connected, for example, to a connection network that offers higher speed than conventional connections; and that (iii) the trust-worthy dependability of a surveillance system depends on various factors, it is not easy to identify which components/devices in a system architecture have the most impact on the dependability for a specific surveillance system in smart cities. In this paper, we developed stochastic Petri net models for a surveillance monitoring system with regard to varying several parameters to obtain the highest dependability. Two main metrics of interest in the dependability of a surveillance system including reliability and availability were analyzed in a comprehensive manner. The analysis results show that the variation in the number of long-term evolution (LTE)-based stations contributes to a number of nines (#9s) increase in availability. The obtained results show that the variation of the mean time to failure (MTTF) of surveillance cameras exposes a high impact on the reliability of the system. The findings of this work have the potential of assisting system architects in planning more optimized systems in this field based on the proposed models.

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