Reliability assessment for solid state drive based on measurement errors and fuzzy failure threshold

Author(s):  
Peng Li ◽  
Jiaxin Yuan ◽  
Wei Dang
2018 ◽  
Vol 39 (12) ◽  
pp. 1908-1911
Author(s):  
Eung Chang Lee ◽  
Jinsung Rho ◽  
Heeyoub Kang ◽  
Bong Jae Lee

Author(s):  
Imam Riadi ◽  
Rusydi Umar ◽  
Imam Mahfudl Nasrulloh

The rapid development of computer technology in hardware, is currently developing non-volatile computer storage media Solid State Drive (SSD). SSD technology has a faster data access speed than Hard Disk and is currently starting to replace Hard Disk storage media. Freezing software on computer systems is often carried out by computer technicians, because it can save a computer maintenance costs due to errors, be exposed to computer viruses or malware. This software is used to prevent unwanted changes to the computer system, when the computer is restarted changes that occur in the computer system will not be stored on storage media. When this happens, what should be done by digital forensic investigators. This study discusses experimental forensic investigations on SSD media storage with frozen conditions or in this study said the frozen SSD. Frozen SSD is the condition of the drive that is locked so that there is no change in the computer system. Software used to lock and prevent changes such as Deep Freeze, Shadow Defender, Windows Steady State, and Toolwiz Time Freeze. Forensic research stages using methods NIST. The result shows that from comparative analysis conducted with Deep Freeze the results of the RecoverMyFile gives 76.38% and Autopsy gives 75,27%, while frozen condition with Shadow Defender the results of the RecoverMyFile gives 59.72% and Autopsy gives 74.44%. So the results of this study indicate the drive freezing software has an effect obtained can be an obstacle in the digital forensic process.  


2021 ◽  
Vol 19 (9) ◽  
pp. 093301
Author(s):  
Kohei Suzuki ◽  
Minori Tao ◽  
Yuki Maeda ◽  
Hirotaka Nakayama ◽  
Ren Noguchi ◽  
...  

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 623
Author(s):  
Xin Ye ◽  
Zhengjun Zhai ◽  
Xiaochang Li

Solid-state drive (SSD) with flash memory as the storage medium are being widely used in various data storage systems. SSD data compression means that data is compressed before it is written to Not-And (NAND) Flash. Data compression can reduce the amount of data written in NAND Flash and improve the performance and reliability of SSDs. At present, the main problem facing data compression of SSD is how to improve the efficiency of data compression and decompression. In order to improve the performance of data compression and decompression, this study proposes a method of SSD data deduplication based on zone division. First, this study divides the storage space of the SSD into zones and divides them into one hot zone and multiple cold zones according to the different erasing frequency. Second, the data in each zone is divided into hot data and cold data according to the number of erasures. At the same time, the address mapping table in the hot zone is loaded into the cache. Finally, when there is a write or read request, the SSD will selectively compress or decompress the data according to the type of different zones. Through simulation tests, the correctness and effectiveness of this study are verified. The research results show that the data compression rate of this research result can reach 70–95%. Compared with SSD without data compression, write amplification is reduced by 5 to 30%, and write latency is reduced by 5 to 25%. The research results have certain reference value for improving the performance and reliability of SSD.


2006 ◽  
Vol 116-117 ◽  
pp. 734-737 ◽  
Author(s):  
Alexander Schönbohm ◽  
Rainer Gasper ◽  
Dirk Abel

The aim of the paper is to demonstrate a control scheme by which it is possible to reproducibly reheat steel billets into the semi-solid state. Usually a heating program is used to reheat the billet into the semi-solid state. Our experiments showed that this control scheme leads to varying semi-solid fractions from one experiment to the next. To gain information about the billet’s state its temperature is often used since there is a known relationship between the temperature and the liquid fraction. Direct measurement of the temperature via thermocouples is not feasible in a production environment, therefore a radiation pyrometer has been used as a contact-less measurement device. The accuracy of the pyrometer depends heavily on the exact knowledge of the radiation coefficient, which can vary from billet to billet due to different surface properties and which is subject to change during the heating process. These uncertainties prohibit the implementation of a closed-loop control scheme since the exact temperature cannot be measured with the required accuracy. In order to be independent of the measurement errors the proposed control scheme only relies on the slope of the temperature. By detecting the distinct change of slope which occurs when the solidus temperature is crossed, the beginning of the melting process can be determined. The energy fed to the billet from this point onward determines the resulting liquid fraction. By detecting the entry into the solidusliquidus interval and then feeding the same amount of energy to each billet, it is guaranteed that the billet reaches the desired liquid fraction even by uncertain absolute value of the temperature and by small variations of the alloy composition. For the experiments the steel alloy X210 has been used and measurement data demonstrate the feasibility of the proposed control scheme.


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