A survey of data recovery on flash memory

In recent years, flash memory has become more widely used due to its advantages, such as fast data access, low power consumption, and high mobility. However, flash memory also has drawbacks that need to be overcome, such as erase-before-write, and the limitations of block deletion. In order to address this issue, the FTL (Flash Translation Layer) has been proposed with useful functionalities like address mapping, garbage collection, and wear-leveling. During the process of using, the data may be lost on power failure in the storage systems. In some systems, the data is very important. Thus recovery of data in the event of the system crash or a sudden power outage is of prime importance. This problem has attracted attention from researchers and many studies have been done. In this paper, we investigate previous studies on data recovery for flash memory from FTL processing solutions to PLR (Power Loss Recovery) solutions that have been proposed by authors in the conference proceeding, patents, or professional journals. This will provide a discussion of the proposed solutions to the data recovery in flash memory as well as an overview

Characterization of myosin, myoglobin, and phospholipids isolated from Pacific sardine (Sadinops sagax)

Myoglobin (Mb) was extracted from Pacific sardine and added to Pacific whiting surimi to measure its effects on protein gelation. The purity of Mb extract was determined by SDS-PAGE. Mb extracted using ethanol showed higher purity than Mb extract using ammonium sulfate. The addition of 0.2% Mb significantly reduced breaking force of Pacific whiting surimi gel. However, a synergistic effect of 1.0% Mb was observed with 1.0% beef plasma protein (BPP) to increase surimi gel strength. The highest storage modulus of gels was observed at 1.0% Mb addition, which corresponded with the non-fracture gel and also supported a synergistic interaction between 1.0% Mb and 1.0% BPP. Differential scanning calorimetry showed Mb addition might have affected myosin denaturation and aggregation. Biochemical and conformational changes of purified sardine myosin were investigated at various pHs. The greatest myosin protein solubility was observed at pH 7 and remained constant up to pH 11. Three endothermic peaks were obtained for samples prepared at pH 7 and 10, while no peaks were shown for pH 2 samples, indicating chemical denaturation of myosin occurred before thermal treatment. The greatest Ca2+-ATPase activity was observed at pH 7, while no activity was observed between pH 2-5 and pH 11. Total sulfhydryl content showed low activity at pH 2.5-4 while the greatest measure was obtained for samples at pH 5.5. Surface hydrophobicity was not detected from pH 2.5 to 5.0 because of low protein solubility, thereafter, the content remained consistent through pH 11. Phospholipids (PL) were extracted from Pacific sardine and added to Alaska pollock surimi to measure its effects on protein gelation. Sep-pak silica column was used with hexane and methanol for PL extraction. The purity of PL extract was determined by thin-layer chromatography and results demonstrated high purity of obtained PL extract. The PL fraction contained higher levels of unsaturated fatty acids than neutral lipids (NL) and total lipids (TL) fractions, respectively. Freeze-thaw process was conducted to rapidly induce changes to see the effects of phospholipids during a long period of storage. Storage modulus was affected by 1% PL addition compared to control during freeze-thaw study. However, PL did not affect to color of Alaska pollock surimi gel

A Review System Based On Product Features In A Mobile Environment

With the rapid growth of the mobile commerce, firms have been trying to get their online channels optimized for the mobile devices. However, many contents on online shopping sites are still focused on a desktop PC environment. Especially, consumer reviews are difficult to browse and grasp via a mobile device. Usually, it is not helpful to simply reduce the size of fonts or photos to fit to mobile devices without a fundamental transformation of the review presentation. In this study, we suggest a feature-based summarization process of consumer reviews in mobile environment. Further, we illustrate an implementation of the process by applying opinion mining techniques to product reviews crawled from a major shopping site in Korean. Finally, a plan for a controlled laboratory experiment is proposed to validate the effectiveness of the suggested review framework in this study

A Framework for Analysis on the Process of Information System Evaluation and Investment Decision

Information System (IS) investment evaluation has long been issue in the IS research. Traditional positivistic research dealt with cost-benefit rationale regarding why and how evaluate. Afterwards social and political view added issue to this stream by embedding the organizational context that makes evaluation more fraught with difficulties. The purpose of this paper is to provide a theoretical foundation and justification of the various organizational aspects of IS evaluation and decision process. By reviewing recent research that adopts institutional theory perspective on this issue and we develop two-staged evaluation process model constructed by the interaction among stakeholders and their roles. Participants of the process are two groups: IS evaluator group who evaluate the benefit of investment, and decision makers who examine suggestion of evaluator group and finally determine to invest or not. We argue that, during this interaction process, the organization’s institutional context influences the extent of the formality of evaluation criteria and the procedural rationality. From this dynamic process perspective, we propose a multidimensional analysis framework that constitutes four types of evaluation orientation: Mixed, Positive, Negative, and Control Evaluation Orientation. With this framework we discuss how stakeholders behave and affect investment decision under each evaluation orientation. Likewise, we also discuss how financially justified IS investments can be sometimes rejected or otherwise accepted in the politically situated evaluation process. We believe that this framework expands our understanding of IS evaluation and decision process and therefore contribute to IS research in this field. Also to practitioners, this study provides several implications regarding how to maintain the formal/rational evaluation procedure and how to acquire organizational consensus under socially complex organizational environment

Elucidating Comminution Steps to Enhance the Value of Surimi from Tropical Fish

Biochemical and rheological properties of surimi were examined based on: 1) salting time (from 18 to 3 min) while maintaining 21 min for total chopping time; 2) total chopping time (from 6 to 21 min) while salting during the final 3 min. Extending salting time significantly increased breaking force and penetration distance while chopping time extension with fixed salting time did not. Salt soluble proteins decreased when salting time decreased; however, this trend performed contrarily against chopping time. A relationship between gel texture and salt soluble proteins was not found. Oxidation of sulfhydryl groups could occur during the chopping process when chopping without salt was extended. A degree of protein unfolding, as noted by surface hydrophobicity, behaved differently against chopping and salting time. Dynamic rheology demonstrated that total chopping time affected denaturation of the myosin tail region more than salting time.Keywords: Protein solubility, Salting, Chopping, Threadfin bream surimi, Textur

OPTIMAL CONGESTION CHARGES IN GENERAL EQUILIBRIUM

This paper deals with pricing and investment decision problems of multi-route and multi-period highway systems in which the congestion is a significant factor in the assessment of system costs. This study approaches this congestion pricing scheme with two different social welfare maximization problems, both of which search for the optimal solutions through general equilibrium analysis. These two optimization problems have an identical structure except financial constraints that reflect different decision environments. One welfare maximization problem involves estimating the first-best social optimal solution. This problem yields the optimal solution for the implementation scheme to impose the differentiated congestion charge for each trip alternative in terms of travel route and trip period. The optimal congestion charge for this problem has the expression similar to that derived in previous studies dealing with congestion pricing. Another maximization problem involves characterizing the second-best optimal solution. In this problem, it is assumed to impose the congestion toll only on a single highway link. This problem yields the second-best congestion toll different from the first-best one. This second-best optimal congestion toll has the structure to reflect its impact on other highway links exempt from the congestion charge program. Document type: Articl