scholarly journals Implementation of Anti Forensics on Hard Drives Using the DoD 5220.22 M Method and British HMG IS5 E

2020 ◽  
Vol 4 (4) ◽  
pp. 736-744
Author(s):  
Muh Fadli Hasa ◽  
Anton Yudhana ◽  
Abdul Fadlil
Keyword(s):  
Performance Test ◽  
Recovery Process ◽  
Disk Drive ◽  
Hard Drives ◽  
Storage Media ◽  
Disk Tool ◽  
Significant Difference ◽  
Forensic Tools ◽  
Recovery Tools ◽  
Test Process

The process of securing data is related to anti-forensic science, one of the anti-forensic techniques that can be used to safeguard data security, namely by deleting data on storage media. This study examines the implementation of data deletion using the DoD 5220.22 M and British HMG IS5 E methods, then compares these methods. The comparison of the two methods includes performance tests, forensic tests, and data recovery tests. The results of the performance test show that the two methods are strongly influenced by the anti-forensic tools used and do not provide a significant difference when applied using one of the tools. The results of the implementation of data deletion using both methods on the hard disk drive are declared safe to delete data, as evidenced by the extraction results in the forensic test using the Autopsy tool found files on the partition :F with the number of 252 files and on the partition :I with the number of 1 file and the extraction results from the test Forensics using the Recover My File tool managed to find files with the number of 102 files on different partitions, but all the files found in the forensic test process cannot be accessed. The results of the recovery test show that the safest method in the process of deleting data is the British HMG IS5 E method using the Active @ Kill Disk tool, as evidenced by all the results of the recovery process using three tools that do not find any files. Meanwhile, the application of the deletion method that is generally carried out by users, namely the shift + delete method, is declared unsafe, as evidenced by the results of the recovery tests conducted showing that the deleted files can be recovered 100% and can be reaccessed using recovery tools.  

scholarly journals Strain Sensing With Piezoelectric Zinc Oxide Thin Films for Vibration Suppression in Hard Disk Drives

2008 ◽  
Author(s):  
Sarah Felix ◽  
Stanley Kon ◽  
Jianbin Nie ◽  
Roberto Horowitz
Keyword(s):  
Vibration Suppression ◽  
Transfer Functions ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drive ◽  
Strain Sensing ◽  
Linear Quadratic ◽  
H2 Control ◽  
Hard Drives ◽  
Optimization Methodology

This paper describes the integration of thin film ZnO strain sensors onto hard disk drive suspensions for improved vibration suppression for tracking control. Sensor location was designed using an efficient optimization methodology based on linear quadratic gaussian (LQG) control. Sensors were fabricated directly onto steel wafers that were subsequently made into instrumented suspensions. Prototype instrumented suspensions were installed into commercial hard drives and tested. For the first time, a sensing signal was successfully obtained while the suspension was flying on a disk as in normal drive operation. Preliminary models were identified from experimental transfer functions. Nominal H2 control simulations demonstrated improved vibration suppression as a result of both the better resolution and higher sensing rate provided by the sensors.

scholarly journals The effects of a single session of lumbar spinal manipulative therapy in terms of physical performance test symmetry in asymptomatic athletes: a single-blinded, randomised controlled study.

2018 ◽  
Vol 4 (1) ◽  
pp. e000389 ◽  
Author(s):  
Bruno A P Alvarenga ◽  
Ricardo Fujikawa ◽  
Filipa João ◽  
Jerusa P R Lara ◽  
António P Veloso
Keyword(s):  
Musculoskeletal Disorders ◽  
Physical Performance ◽  
Performance Test ◽  
Statistical Significance ◽  
Spinal Manipulative Therapy ◽  
Controlled Study ◽  
Eligibility Criteria ◽  
Manipulative Therapy ◽  
Significant Difference ◽  
Randomised Controlled

Background and aimMusculoskeletal disorders in athletes, including spinal biomechanical dysfunctions, are believed to negatively influence symmetry. Spinal manipulative therapy (SMT) is recognised as a safe and effective treatment for musculoskeletal disorders, but there is little evidence about whether it can be beneficial in symmetry. Therefore, this study aimed to measure the effects of lumbar SMT in symmetry.MethodsForty asymptomatic athletes participated in the study. The randomisation procedure was performed according to the following group allocation: group 1 (SMT) and group 2 (SHAM). Each participant completed a physical activity questionnaire, and also underwent clinical and physical evaluation for inclusion according to eligibility criteria. Statistical significance (P<0.05) between groups and types of therapy were calculated by physical performance tests symmetry (static position, squat and counter movement jump (CMJ), pre- and post-SMT and SHAM. There were 14 trials of three symmetry tests for each participant, for a total of 560 trials.ResultsLumbar SMT produced immediate effects in symmetry in the static position; however, the same effects were not found in squat and CMJ on symmetry 1. Therefore, our results showed a significant difference in pre- (mean 16.3%) and post-lumbar SMT (mean 3.7%) in static symmetry. However, symmetry 2 showed no statistical significant differences for any of the tests and intervention groups. No statistically significant effects in symmetry pre- to post-SHAM were found in any of the tests.ConclusionsStatistically significant differences were found in lumbar SMT, but only for static symmetry. These findings suggest that SMT was effective in producing immediate effects in symmetry in the static position, but none in dynamic tests. Future studies could address our study's limitations.Clinical trials register numberNCT03361592.

One night sleep restriction impairs the cortical oxygenation responses

2011 ◽  
Vol 26 (S2) ◽  
pp. 1560-1560
Author(s):  
S. Miyata ◽  
A. Noda ◽  
M. Ito ◽  
K. Iwamoto ◽  
N. Ozaki
Keyword(s):  
Cognitive Function ◽  
Performance Test ◽  
Sleep Restriction ◽  
Night Sleep ◽  
Word Fluency ◽  
Insufficient Sleep ◽  
Neurobehavioral Function ◽  
Significant Difference ◽  
Concentration Changes ◽  
Fluency Task

IntroductionSleep restriction has adverse effects on performance and neurobehavioral function. However, the mechanism of impaired performance and neurobehavioral function has not been studied yet.ObjectivesWe examined the effect of insufficient sleep on cerebral blood flow and cognitive function in 8 healthy adults (mean age 22.4 years).MethodsAll participants were in bed for 8 h (sufficient sleep), and for < 4 h (insufficient sleep). The oxyhemoglobin (oxyHb) level by a word fluency task was measured with a near-infrared spectroscopy recorder on the morning following sufficient and insufficient sleep periods. Wisconsin card sorting test (WCST), continuous performance test (CPT) and N-back test were evaluated on the same days.ResultsThe peak oxyHb level was significantly lower in the left and right frontal lobes after insufficient sleep than after sufficient sleep (left: 0.25 ± 0.10 vs. 0.70 ± 0.29 mmol, P < 0.05; right: 0.23 ± 0.13 vs. 0.73 ± 0.22 mmol, P < 0.05). There was no significant difference in the number of words generated during the word fluency task between sufficient and insufficient sleep states. The percentage of correct responses on CPT after insufficient sleep was significantly lower than that after sufficient sleep (86.6 ± 10.2 vs. 96.0 ± 4.9%, P < 0.05). The reaction time of WCST was significantly longer after insufficient sleep than after sufficient sleep (76.6 ± 13.4 vs. 70.6 ± 16.2 sec, P < 0.05).ConclusionsOne night sleep restriction decreased the concentration changes of oxyHb in brain tissue, leading to impaired cognitive function.

scholarly journals Analgesic Effect of Apotel Versus Pethidine After Hemilaminectomy

2019 ◽  
Vol 5 (4) ◽  
pp. 185-189
Author(s):  
Mohammadreza Emamhadi ◽  
◽  
Hamid Behzadnia ◽  
Seifollah Jafari ◽  
Mohammadreza Zamanidoust ◽  
...  
Keyword(s):  
Recovery Process ◽  
Cross Sectional Study ◽  
Medical Sciences ◽  
Cross Sectional ◽  
Vas Score ◽  
Relieve Pain ◽  
Present Cross Sectional Study ◽  
Significant Difference ◽  
Vas Scores ◽  
The Difference

Background: Postoperative pain is a common phenomenon, and its management affects considerably on the recovery process, and patients’ satisfaction. Apotel and pethidine are two conventional medicines used to relieve pain after operation. Objectives: The present study aimed to compare the effect of intravenous injection of Apotel and intramuscular injection of pethidine in relieving pain after hemilaminectomy. Materials & Methods: In the present cross-sectional study, 150 patients who underwent hemilaminectomy were recruited between May 2015 and November 2015. They were taking either Apotel (n=75) or pethidine (n=75) after the operation, which was done at Poursina Hospital affiliated to Guilan University of Medical Sciences, Rasht City, Iran. The patients’ pain levels were measured using visual analog scale (VAS), and the results were compared between the 2 groups. Results: There was no significant difference in the total VAS score between the Apotel and pethidine groups (P=0.189). However, there was a significant reduction in VAS score hours 2 (P=0.03) and 4 (P=0.004) hours after the injection of Apotel in this group, compared with those scores in the pethidine group. Also, VAS scores at other times (8, 12, 20, 28 hours after the injection) were lower than those in the pethidine group, but the difference was not significant. Conclusion: Apotel was better pain-killer in the early hours after the first injection compared to pethidine. But its effect was similar to pethidine at the late hours after the first injection. Therefore it seems that Apotel is better painkiller after laminectomy, especially in the early hours after the operation.

scholarly journals Learning Effects, Achievement Goals and Time Constraints in Accounting Education: Findings from Experiments

2018 ◽  
Vol 6 (2) ◽  
pp. 35
Author(s):  
Pi-Yueh Cheng ◽  
Miao-Ling Fang
Keyword(s):  
Performance Test ◽  
Goal Orientations ◽  
Achievement Goal ◽  
Accounting Education ◽  
Learning Performance ◽  
Test Time ◽  
Score Change ◽  
Performance Achievement ◽  
Accounting Performance ◽  
Significant Difference

Accounting education has been a topic of great concern to scholars, and teachers of accounting want to enhance students’ learning performance. Thus, in this study, we conducted laboratory experiments to investigate how mastery/performance achievement goal orientations influence the accounting performance of students. Ninety undergraduates from Tainan Technology University participated in this study. The experiment examined how the type of student achievement goal and the test time influenced accounting performance. A two-way between-participants factorial design of achievement goal (mastery vs. performance) × test time (30 vs. 40 vs. 50 min) was adopted. The results of students’ score changes from pre-test to post-test revealed that those students with a mastery achievement goal had a better learning effect than those with a performance achievement goal. The main effect of test time also showed a significant difference. The score change in the low-difficulty condition (longest time) was significantly higher than that in the moderate-difficulty condition (intermediate amount of time), and the score change in the moderate-difficulty condition was significantly higher than that in the high-difficulty condition (shortest time). Lastly, the two-way interaction of achievement goal type and test time was significant. The effect of test difficulty on score change was contingent on the type of achievement goal.

scholarly journals Using Google Docs in Omani EFL College Classes: Students’ Writing Performance and Perceptions towards Use

2019 ◽  
Vol 8 (1) ◽  
pp. 53
Author(s):  
Noura Al Burtamani ◽  
Fawzia Al Seyabi ◽  
Abdo Al Mekhlafi
Keyword(s):  
Performance Test ◽  
Control Group ◽  
Writing Performance ◽  
Google Docs ◽  
Significant Difference ◽  
Foundation Program ◽  
Post Test ◽  
Quasi Experimental ◽  
College Classes ◽  
Experimental Group

This quasi experimental study aimed at investigating the effect of using Google Docs on EFL Omani college students’ writing performance and students’ perceptions of its use. The sample of the study included 81 Level 3 Foundation Program students in Nizwa College of Technology, Oman. The experimental group consisted of 39 students while the control group consisted of 42 students. The research instruments included a writing performance test that was administered as pre and post- test and a students’ perceptions questionnaire. Data analysis revealed that there was a statistically significant difference between the writing performance of the experimental and control groups in favour of the experimental group. The experimental group outperformed the control group in task achievement, task organization, grammar and vocabulary. Also, the students perceived using Google Docs in EFL writing as a very beneficial tool in improving their writing and collaboration skills. In light of these findings, a number of recommendations for practice are presented.

Evolution of Synthetic Fluid from Water Extract from Fermented Ground Maize (WEFGM) as an Alternative to Water-Based Cutting Fluids: Performance Test

2018 ◽  
Vol 1150 ◽  
pp. 59-66
Author(s):  
Taofeek Ayotunde Yusuf ◽  
Chibueze Nnorom ◽  
Olusola Femi Olusunmade
Keyword(s):  
Performance Test ◽  
New Technologies ◽  
Temperature Drop ◽  
Water Extract ◽  
Deionized Water ◽  
Additive Concentration ◽  
Actual Performance ◽  
Two Samples ◽  
Significant Difference ◽  
Water Based

The use of agricultural wastes and natural materials in new technologies is a novel subject. Consequently, an attempt has been made to formulate a synthetic fluid using an organic water, Water Extract from Fermented Ground Maize (WEFGM) and compare its performance with water-based sample in turning operation using a mild steel as workpiece. Two samples of synthetic fluids were formulated from each of deionized WEFGM, ordinary WEFGM and deionized water as base-fluids at two composition (5 and 10%vol) levels of selected additives. The results of experimental analysis of heat transfer properties of these synthetic fluids exist, hence the need to ascertain the actual performance output. Temperature-Time Gradient (TTG) which is a rate of temperature drop (heat withdrawn) from the work zone was used as evaluation parameters. The result showed that deionized WEFGM is the most efficient of the entire samples at both compositions with an average TTG of 3.61 and 2.16 °C/min at 10 and 5% additive concentration respectively. At lower additive concentration which is more economically advantageous, the performance rating is deionized WEFGM>>WEFGM>>deionized Water. This implies that WEFGM is more effective than water as a base fluid for synthetic fluid in performance as it has been previously so reported in properties. Meanwhile, T-test statistical analysis (using IBM SPSS 23) shows that there is highly significant difference in TTG at each time of application of individual fluid (p<0.05). However, TTG of one fluid sample is not significantly different from the other (p>0.05) implying that the fluids can all work as coolants and relatively have comparable performance output.

Dance Movement Instruction: Effects on Spatial Awareness in Visually Impaired Elementary Students

1988 ◽  
Vol 82 (5) ◽  
pp. 188-192 ◽  
Author(s):  
D.L. Chin
Keyword(s):  
Physical Education ◽  
Elementary Students ◽  
Visually Impaired ◽  
Performance Test ◽  
Spatial Awareness ◽  
Dance Movement ◽  
Movement Instruction ◽  
Significant Difference ◽  
Before And After ◽  
Dance Instruction

The purpose of the study presented here was to investigate the effects of instruction in dance movement on the spatial awareness of visually impaired elementary students. Sixteen visually impaired students were randomly assigned to two groups. Eight students participated in physical education and received no dance instruction. Eight students received dance instruction in addition to physical education. The Hill Performance Test of Selected Positional Concepts was administered before and after the treatment period. An analysis of variance revealed significant main effects. A Scheffé analysis revealed a significant difference between the pretest and posttest scores of the group that received dance instruction.

Design and Performance Test of Comb-Shaped Clamp/Spacer for Improvement of Recirculation Filter Efficacy in a Hard Disk Drive

2009 ◽  
Vol 45 (1) ◽  
pp. 201-205 ◽  
Author(s):  
Sung-Eun Park ◽  
Dae-Young Lee ◽  
Jae-Hong Park ◽  
Tae-Sik Kang ◽  
Jin-Gyoo Yoo ◽  
...  
Keyword(s):  
Hard Disk Drive ◽  
Performance Test ◽  
Hard Disk ◽  
Disk Drive ◽  
And Performance

Numerical Modeling for the Characterization of Flow Excitation for the HDD Disk Vibration Control

2006 ◽  
Vol 110 ◽  
pp. 143-150
Author(s):  
Ja Choon Koo ◽  
Sean W. Kang ◽  
Y.S. Han ◽  
Yeon Sun Choi
Keyword(s):  
Data Storage ◽  
High Performance ◽  
Air Flow ◽  
Flow Analysis ◽  
Disk Drive ◽  
Squeeze Film ◽  
Hard Drives ◽  
Design Improvement ◽  
Disk Flutter

This article presents a modeling method for air flow analysis of a hard disk drive. Air flow excitation causes disk vibration that aggravates TMR budget of the design of modern high performance hard drives. And it is the most expensive budget consumer so that controlling of the flutter becomes the primary design issue of the data storage industry. In the presented work, air flow excitation forces are characterized by LES modeling and the results are verified with experiments. A squeeze-film-type disk damper is employed in the experiments and it is applied for a hardware design improvement for disk flutter reduction. LES and RANS are compared and alternately used in a calculation in order to minimize computational efforts.

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