Chapter 6 - Secondary Storage

Efficient buffering for concurrent disk and tape I/O

Exploring new electrolyte materials is important to comprehend high performance secondary charge storage devices for effective utilization of renewable energy. Ionic liquids with broad electrochemical voltage window and wide range of thermal stability are prospective materials for the same. As an improved version of this class of materials, we report herein, on the synthesis of novel pyrrolidinium based ionic liquid tethered nanoparticle hybrid electrolytes and compared their conductivity and electrochemical cycling behaviors. Hybrid electrolytes are prepared by covalently grafting N-Methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl) imide to the surfaces of pre-synthesized TiO2 nanoparticles at three different core volume fractions, ranging from 0.11 to 0.46. Uniform dispersion of the core nanoparticle within the matrix of the electrolytes improves their mechanical properties. With increasing core volume fractions, the electrical conductivity slightly decreases due to increasing viscosity. Nevertheless, nanoparticle grafting significantly improves the electrochemical performance of the electrolytes. The electrolytes show very good capacitance retentivity (>90%) and long-term cycling stability above room temperature even at the lowest grafting density within symmetric stainless steel electrodes. Impressive room temperature electrochemical performance of these materials within symmetric supercapacitor cell containing CMS graphite as electrodes further demonstrates the applicability of these hybrid materials as promising electrolytes for secondary charge storage devices.

An archiving model for a hierarchical information storage environment

One of the key components of a hybrid electric vehicle (HEV) drive train is its secondary energy storage device. The automotive industry is still in the process of debating on the fact, as to which device provides the best option in HEVs, for the purpose of load leveling. This paper aims at providing a fair idea with regards to the selection of secondary energy sources, based on vehicle performance characteristics and overall drive train efficiency. The performances of lead-acid (PBA), lithium-ion (Li-Ion), nickel-cadmium (Ni-Cd), nickel-metal hydride (Ni-MH), and nickel-zinc (Ni-Zn) batteries, as well as ultra-capacitors (UC) are investigated over city and highway driving schedules for a heavy-duty diesel-parallel hybrid transit bus application. Based on the simulation studies for the above-mentioned storage devices, the Ni-MH, PBA, and the ultra-capacitor technologies demonstrate best results in terms of fuel economy and percentage drive train efficiency. On the other hand, the Ni-Zn and Li-Ion batteries show much promise, but still demand a great deal of research and development work, before they become a viable option for HEV applications. Finally, the paper compares and summarizes critical performance characteristics for the energy storage devices under investigation.

A very fast parallel object store for very fast applications

Performance analysis of an Injera baking machine by using solar energy

Storage and retrieval of database constraints

A write blocker allows read-only access to digital data on a secondary storage device by placing a hardware or software filter between the host computer and the storage device. The filter monitors I/O commands sent from the application on the host computer, only allowing commands to the device that make no changes to its data. This paper examines the I/O commands used to access secondary storage devices and discusses their implications for BIOS-based and hardware-based write blockers.

As the Maximum malwares are spread from the external devices and they may infect to the system, maintaining security while transmission of data from the external storage device to the system is more challengeable in today’s computer world. Malware is malicious software used to collect sensitive info or gain entrance to private computer system. Applications provide facilities for detect and prevent the malware. The aim of this paper is to detect the malware for an external storage device and maintain security and evade losing of data. Security is more significant, thus it requires to make a more secure model which can automatically provide the malware protection from the external storage devices. This application program designed is used to protect external devices like pen-drive, HDD etc. The software is loaded into external devices which user wants to protect from harmful data from the system. Hence, such type of application can be used for protecting external devices.

Chapter 1 - Fundamental electrochemical energy storage mechanisms

A compact 180 kV electron beam system is designed for high power microwave generation. The electron beam system is consists of a secondary energy storage device, which can deliver energy to the load at faster rate than usual primary energy storage system such as tesla transformers or marx generator. The short duration, high voltage pulse with fast rise time and good flattop is applied to vacuum diode for high power microwave generation. The compact electron beam system is made up of single turn primary tesla transformer which charges a helical pulse forming line and transfers its energy to vacuum diode through a high voltage pressurized spark gap switch. We have used helical pulse forming line which has higher inductance as compared to coaxial pulse forming line, which in turns increases, the pulse width and reduce the length of the pulse forming line. Water dielectric medium is used because of its high dielectric constant, high dielectric strength and efficient energy storage capability. The time dependent breakdown property and high relative permittivity of water makes it an ideal choice for this system. The high voltage flat-top pulse of 90 kV, 260 ns is measured across the matched load. In this article we have reported the design details, simulation and initial experimental results of 180 kV pulsed electron beam system for high power microwave generation.

In Memory Computing is moving data into dynamic memory which is traditionally stored in secondary storage devices. In this paper we try to improve the capability of Java Virtual Machine (JVM) to process large data collections/application by pertinence of In-Memory Computing concepts. It helps JVM/processor to process huge data sets efficiently due to high-speed access and reduction of latency of slow secondary storage devices. It is implemented by providing more dynamic memory to JVM or by the implementation of In Memory Database concepts. In this paper we correlate Actual machine with JVM and try to improve ability of JVM to process large data collections by eliminating disk access and replacing Database with JAVA Collections in the Model Layer hence using `in memory' concepts, Henceforth a high performance system is designed.

The problem of determining page size in a page on demand system is discussed in detail in this paper. After having introduced the problem, the effect page size may have on various system performance measures is reviewed based on measurements of program behaviour and on simple models of system behaviour. This discussion is followed by a detailed study of the effect of the choice of page size on the efficient utilization of primary memory space. The wasted space-time integral (WSTI) of primary memory space is selected as a measure of this utilisation and a new model of program and system behaviour is used to compute the WSTI for different secondary memory devices (drum, ECS and LCS) and different system behaviour parameters such as the time spent in supervisor mode by the operating system to initiate a page transfer, the time spent in the CPU queue by a program which has recovered from a page fault before it receives the attention of the CPU, the global page fault rate (or arrival rate at the secondary storage devices used for paging) and other factors. The influence of each of these factors is discussed and analyzed, and the conditions under which one or another of these dominates the problem is identified. In the Appendix, one of the problems posed by our model, the use of approximate formulae for fragmentation which remain valid for a large class of probability distribution functions of program size, is analyzed in detail. Some tests are developed for the validity of these formulae.

Along with the development of technology, especially computer and internet, we can get information more easily. It also encourages the number of computer users and the internet is getting bigger. Especially in the environment of PT. Prism Dynamics Indonesia, the number of employees who use the internet more and more from time to time. Increasing users who use the network will cause the existing network infrastructure, should be increased so as not to make users disappointed due to decreased network performance. At PT. Prism Dynamics Indonesia a lot of important files that must be stored starting from the data project, finance, sales, purchasing and service of goods, all hardcopy data or softcopy if not stored properly then there will be damage to the data or even lost. it takes a centralized data storage container like file sharing. File sharing is a system where many users can share files and storage resources with a client-server concept run over the network. A file server allows users to share information over a network without having to physically send files with floppy disks or some other external storage device.

Audit software for data analytics, most commonly known as Generalised Audit Software (GAS), has been used by audit organisations since the deployment of IT in business organisations. The use and importance of GAS has increased with the growth in the sophistication and proliferation of IT within business organisations. Despite this development, recent studies have reported that GAS is still underused and identified that the factor contributing most to such underutilisation of GAS is access to organisational data. Although the current state of GAS enables auditors to directly access data stored in databases, it is still uncommon for auditors to use this GAS capability. Auditors more commonly obtain organisational data from the auditees’ staff by using secondary storage devices. The audit literature has found problems associated with analysing auditee-provided data, for example, being presented with manipulated data and has, therefore, advocated the importance of having direct access to organisational data. The literature further claims that having direct access to organisational data would provide greater benefits to audit organisations from their investments in GAS through, for example, improved audit efficiency and effectiveness. The audit literature, however, provides limited empirical evidence to support such a recommendation. This thesis seeks empirical evidence on the impact of having direct access to organisational data on the quality of auditor’s analytical tests as representing the dimension of actual audit quality. Drawing on the theory of flow, a supportive condition for innovative behaviour, this study posits that having direct access to organisational data facilitates the creation of a flow state. When auditors experience flow state, they are motivated to use GAS more innovatively. Further, as auditors’ innovative use of GAS increases, auditors are better able to identify successful applications of GAS that, in turn, improve the quality of their analytical tests. This thesis uses a mixed-method approach involving both interviews and a survey to gather data to test its research hypotheses. The interviews and the survey targeted auditors with differing levels of seniority who have used GAS or are actively involved in using it for auditing. The results show support for the research model. The results indicate that, having a sense of control over the use of GAS, the ability to focus on interactions using GAS, the extent of auditors’ professional scepticism, and having knowledge/skills of GAS motivates auditors to use GAS innovatively. The results also indicate that, when the innovative use of GAS increases, the quality of analytical tests also increases. Analysis of the impact of having direct, compared to indirect, access to organisational data shows a statistically significant moderating effect on the extent of auditors’ professional scepticism and on their ability to focus on their interactions with GAS. The results indicate that auditors’ professional scepticism increases, while their ability to focus on the interaction decreases when they have direct access to organisational data. Analysis of the effect of direct access also found no statistically significant difference in the quality of auditor’s analytical tests. These findings enrich current discussion within IT auditing literature on the effectiveness of IT-based audit procedures to obtain audit evidence. This thesis demonstrates that innovative use of GAS is an appropriate link between IT-based audit methods and audit quality, a matter that has been barely elaborated. Additionally, this thesis identifies that the length of GAS experience affects both auditors’ preferences about type of data access (i.e., direct versus indirect access) and their perceptions of the benefits of data access on audit quality. Audit organisations might, therefore, conceive strategies to shorten the time required to realise the benefits of using GAS to directly access organisational data.