• Title/Summary/Keyword: Embedded File System

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Embedded Object-Oriented Micromagnetic Frame (OOMMF) for More Flexible Micromagnetic Simulations

  • Kim, Hyungsuk;You, Chun-Yeol
    • Journal of Magnetics
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    • v.21 no.4
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    • pp.491-495
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    • 2016
  • We developed an embedded Object-Oriented Micromagnetic Frame (OOMMF) script schemes for more flexible simulations for complex and dynamic mircomagnetic behaviors. The OOMMF can be called from any kind of softwares by system calls, and we can interact with OOMMF by updating the input files for next step from the output files of the previous step of OOMMF. In our scheme, we set initial inputs for OOMMF simulation first, and run OOMMF for ${\Delta}t$ by system calls from any kind of control programs. After executing the OOMMF during ${\Delta}t$, we can obtain magnetization configuration file, and we adjust input parameters, and call OOMMF again for another ${\Delta}t$ running. We showed one example by using scripting embedded OOMMF scheme, tunneling magneto-resistance dependent switching time. We showed the simulation of tunneling magneto-resistance dependent switching process with non-uniform current density using the proposed framework as an example.

A Method of Embedded Linux Light-Weight for Efficient Application Execution (어플리케이션 처리속도 개선을 위한 임베디드 리눅스 경량화 기법)

  • Lee, Tae-Woo;Cho, Ji-Yong;Cho, Yong-Hwan
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.3
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    • pp.1-10
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    • 2013
  • In this paper, we propose a method of embedded linux light-weight to improve efficiency of application running on embedded systems. Three methods including fast booting scheme applying the Hibernation technique, JFFS2 file system optimization applying the Symbolic Link and virtual address mapping, kernel light-weight that guarantees the general purpose was applied. Since then check the system dependency and generate kernel image according to the target embedded kit. And embedded system performance of existing linux and linux which the method proposed in this paper was compared. In experimental result, the kernel size was 9.6% improved and the system booting time was 18% improved. And application processing speed on target embedded kit was improved 11% in the best case, 66% in the worst case. This result show that the light-weight method proposed in this paper is guarantee fast booting time and securing resources and it is good for the application processing speed improvement.

A Study of Purity-based Page Allocation Scheme for Flash Memory File Systems (플래시 메모리 파일 시스템을 위한 순수도 기반 페이지 할당 기법에 대한 연구)

  • Baek, Seung-Jae;Choi, Jong-Moo
    • The KIPS Transactions:PartA
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    • v.13A no.5 s.102
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    • pp.387-398
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    • 2006
  • In this paper, we propose a new page allocation scheme for flash memory file system. The proposed scheme allocates pages by exploiting the concept of Purity, which is defined as the fraction of blocks where valid Pages and invalid Pages are coexisted. The Pity determines the cost of block cleaning, that is, the portion of pages to be copied and blocks to be erased for block cleaning. To enhance the purity, the scheme classifies hot-modified data and cold-modified data and allocates them into different blocks. The hot/cold classification is based on both static properties such as attribute of data and dynamic properties such as the frequency of modifications. We have implemented the proposed scheme in YAFFS and evaluated its performance on the embedded board equipped with 400MHz XScale CPU, 64MB SDRAM, and 64MB NAND flash memory. Performance measurements have shown that the proposed scheme can reduce block cleaning time by up to 15.4 seconds with an average of 7.8 seconds compared to the typical YAFFS. Also, the enhancement becomes bigger as the utilization of flash memory increases.

Designing a Embedded System for Remote Control of LDM (LDM 원격 제어를 위한 임베디드 시스템 구성)

  • Moon Cheol-Hong;Kang Sang-Woo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.8 s.338
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    • pp.27-34
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    • 2005
  • In this paper, FPGA It/w and S/W Embedded system for LDM remote control is implemented. XScale CPU is used on developed system and in communcation ethenet and serial is used. CPU interface with H/W LDM rotation and to drive LDM FPGA logic is implemented, to transmit LDM data from long distance command packet is composed, for S/W Embedded linux is used to design linux device driver and linux application program. This S/W is run by module so by loading this module to linu)( file system it can do any movement. Also by compiling Embedded linux to the system it can lower the price of the system. By using this H/W and S/W theory it can be used on any other embedded system.

Development of a Real-time Error-detection System;The Case study of an Electronic Jacquard

  • Huh, Jae-Yeong;Seo, Chang-Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2588-2593
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    • 2003
  • Any system has the possibility of an error occurrence. Even if trivial errors were occurred, the original system would be fatally affected by the occurring errors. Accordingly, the error detection must be demanded. In this paper, we developed a real-time error detection system would be able to apply to an electronic Jacquard system. A Jacquard is a machine, which controls warps while weaving textiles, for manufacturing patterned cloth. There are two types of mechanical and electronic Jacquard. An electronic Jacquard is better than a mechanical Jacquard in view of the productivity and realizability for weaving various cloths. Recent weaving industry is growing up increasingly due to the electronic Jacquard. But, the problem of wrong weaving from error data exists in the electronic Jacquard. In this research, a real-time error detection system for an electronic Jacquard is developed for detecting errors in an electronic Jacquard in real-time. The real-time system is constructed using PC-based embedded system architecture. The system detects the occurring errors in real-time by storing 1344 data transferred in serial from an electronic Jacquard into memory, and then by comparing synchronously 1344 data stored into memory with 1344 data in a design file before the next data would be transferred to the Jacquard for weaving. The information of detected errors are monitored to the screen and stored into a file in real-time as the outputs of the system. In this research, we solve the problem of wrong weaving through checking the weaving data and detecting the occurred errors of an electronic Jacquard in real-time.

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Design and Implementation of MPEG-7 Based Video Management System for Mobile Devices (모바일 단말기를 위한 MPEG-7 기반의 비디오 관리 시스템의 설계 및 구현)

  • Ahn Byeong-Tae;Min Jeong-Hoon;Kang Byeong-Shoo;Kang Hyun-Syug
    • Journal of Korea Multimedia Society
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    • v.9 no.4
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    • pp.401-413
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    • 2006
  • We propose video management system based on MPEG-7 for mobile device(MVMS). Most of existing MPEG-7 applications manage MPEG-7 document based on file system in the desktop environment. To contrast them, because the MVMS manages only necessary information using embedded database system for MPEG-7 documents in mobile devices, it can use efficiently lack of the resource in mobile device environment. MVMS supports key image extraction and MPEG-7 document edition function. Moreover, this is possible search and management of multi document because of MVMS manage MPEG-7 data through embedded DB.

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Consideration of fsync() of the Ext4 File System According to Kernel Version (커널 버전 별 Ext4 파일 시스템의 fsync()에 대한 고찰)

  • Son, Seongbae;Noh, Yoenjin;Lee, Dokeun;Park, Sungsoon;Won, Youjip
    • Journal of KIISE
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    • v.44 no.4
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    • pp.363-373
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    • 2017
  • Ext4 file system is widely used in various computing environments such as those of the PC, the server, and the Linux-based embedded system. Ext4, which uses a buffer for block I/O, provides fsync() system call to applications to guarantee the consistency of a specific file. A log of the analytical studies regarding the operation of Ext4 and the improvement of its performance has been compiled, but it has not been studied in detail in terms of kernel versions. We figure out that the behavior of fsync() system call is different depending on the kernel version. Between the kernel versions of 3.4.0 and 4.7.2, 3.4.0, 3.8.0, and 4.6.2 showed behavioral differences regarding the fsync() system call. The latency of fsync() in kernel 3.4.0 is longer than that of the more-advanced 3.7.10; meanwhile, the characteristics of 3.8.0 enabled the disruption of the Ext4 journaling order, but the ordered defect was solved with 4.6.2.

Design and Implementation of Map Databases for Telematics and Car Navigation Systems using an Embedded DBMS

  • Joo, Yong-Jin;Kim, Jung-Yeop;Lee, Yong-Ik;Moon, Kyung-Ky;Park, Soo-Hong
    • Spatial Information Research
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    • v.14 no.4 s.39
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    • pp.379-389
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    • 2006
  • Map databases for CNS (Car Navigation System) can be accessed quickly and compressed efficiently due to that these are usually recorded as in a PSF (Physical Storage Format). However, it is difficult to create and manage data storage based on a file-system. To solve these problems, DBMS needs to be combined with spatial data management. Therefore, we developed an embedded DBMS with which to store data and conduct quick searches in CNS. Spatial data could be easily managed and accessed using the compression method, Multi-Link, spatial index, and spatial division. In the result, the proposed embedded DBMS searched quickly and stably supported data management. If synchronization is applied in DBMS, it is expected to utilize the advantages of an embedded DBMS.

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