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Displaying 1-12 of 12 articles from this issue
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Article type: Cover
Pages Cover1-
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (13K) -
Article type: Index
Pages Toc1-
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (51K) -
Hidetoshi SAITO, Takuya OGAWA, Yoshihiro OKAMOTO, Hisashi OSAWAArticle type: Article
Session ID: MMS2002-33
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSRecently, the encoding/decoding systems based on concatenated codes with several error correction codes are actively studied and effective performance improvements are obtained. In this report, the system for recoding code is proposed using a high dimensional parity check code known as a concatenated code with high error correction capability in digital communication. Especially, our soft decision decoding method is based on error detection using a parity check (tentative decision) and threshold decision for the reliability of error symbols (final decision). As a result, it is clear that the performances of these parity check codes are superior to that of the conventional 16/17(0,6/6) code.View full abstractDownload PDF (792K) -
Masayuki HAYASHI, Noriyuki SHIMIZU, Shouhei ITOU, Ryuji KOHNOArticle type: Article
Session ID: MMS2002-34
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSBER performance improvement of recording system referring jitter noise is studied. Jitter noise depends on recording signals, because the transition position jitter is the cause of jitter noise. We pay attention to the dependence on signals, and verified by computer simulation that the average and the dispersion of jitter like noise are different in each branches of Trellis diagram which is used in Viterbi algorithm. Futhermore, we proposed the calculation method of the path metric which includes the difference of the average and the dispersion. Simulation is used for evaluating BER of proposed scheme.View full abstractDownload PDF (637K) -
Hisashi OSAWA, Nobuhiro MAETO, Yoshihiro OKAMOTO, Hidetoshi SAITO, Hir ...Article type: Article
Session ID: MMS2002-35
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSThe performance of guided scrambling (GS) coded PRML system in a perpendicular magnetic recording channel with jitter-like media noise and distortion due to low frequency cutoff is studied. The bit error rate performance of PR2ML systems for two types of GS codes, Galois field (GF) additive type and convolutional operation type, is obtained and compared with that of conventional Reed-Solomon (RS) coded PR2ML system. The results show that the SNR improvements of GS coded PR2ML systems over RS coded PR2ML system are about 9.3 dB for GF additive type code and 8.3 dB for convolutional operation type code at a normalized linear density of 1.5, a power ratio of jitter-like media noise of 80% and a low-cutoff frequency normalized by bit rate of 0.003.View full abstractDownload PDF (730K) -
Nobuhiko FUNABASHI, Eiichi MIYASHITA, Ryo TAGUCHI, Kiyoshi KUGA, Takah ...Article type: Article
Session ID: MMS2002-36
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSRecording characteristics and thermal decay of Tb-Fe-Co/Co-Cr-Pt-B perpendicular composite media were measured in various thickness of amorphous layers. The relationship between magnetic cluster size and recording characteristics were investigated from observed recorded bit pattern using MFM.View full abstractDownload PDF (583K) -
K. MIURA, M. HASHIMOTO, H. MURAOKA, Y. NAKAMURAArticle type: Article
Session ID: MMS2002-37
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSVoronoi cells noise calculation which took in head field gradient and switching field distribution was performed. The existence of magnetic cluster is needed to explain measured transition jitter. Narrow switching field distribution effectively reduces transition width and transition jitter. The correlation between medium noise saturation against recording density and transition fluctuation from MFM image analysis was studied. Finite size of magnetic cluster results in the noise saturation.View full abstractDownload PDF (768K) -
Shunji TAKENOIRI, Yasushi SAKAI, Sadayuki WATANABE, Kazuo ENOMOTO, Hir ...Article type: Article
Session ID: MMS2002-38
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSSiO_2 added CoPtCr magnetic layer is employed for perpendicular recording media. The microstructure, magnetic properties, and recording performance of these media are discussed. Fine grains with the size of 〜7 nm, surrounded by amorphous-like grain boundaries, are realized. It is considered that the addition of SiO_2 to CoPtCr is very effective to realize well isolated fine grain structure without disturbing the epitaxial growth of CoPtCr grains on Ru underlayer. The medium with 12 nm-thick recording layer shows a large perpendicular anisotropy K_u of 〜4x1O^6 erg/cm^3, high coercivity H_c of 〜6 kOe, and excellent SNR performance. These results indicate that the CoPtCr- SiO_2 granular medium has a great potential for high-density perpendicular recording media.View full abstractDownload PDF (699K) -
Jun KAWAJI, Junichi SAYAMA, Toru ASAHI, Jiro HOKKYO, Tetsuya OSAKAArticle type: Article
Session ID: MMS2002-39
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe have investigated the effect of the addition of a C or Si intermediate layer to a recording layer on read-write characteristics for [Co/Pd]_n perpendicular magnetic recording media. The introduction of a 1nm-thick C layer improved the recording resolution (D_<50>) and reduced the medium noise, which resulted in the improvement of S/N ratio by 5 dB at the recording density of higher than 200 kFRPI. On the other hand, the Si intermediate layer did not improve the read-write characteristics in [Co/Pd]_n media. From the results of the plan-view TEM and MFM observations, it is considered that the 1nm-thick C layer suppressed the crystal-grain growth in [Co/Pd]_n multilayer and thereby the boundary of magnetic transition between recording bits became close to straight, leading to the improvement of read-write characteristics. Moreover, no decay of remanent magnetization was observed for the [Co/Pd]_n medium with the C intermediate layer of 1 nm thickness, which showed good thermal stability for the medium.View full abstractDownload PDF (759K) -
Yoichiro TANAKA, Kazuhito SHIMOMURA, Akihiko TAKEOArticle type: Article
Session ID: MMS2002-40
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSPerpendicular recording has been actively developed for future high density recording system. We studied the integration of the perpendicular recording system to the hard disk drive (HDD). Double layer perpendicular media and singlepole type perpendicular head were employed in 2.5"HDD along with the channel with a differential equalization. As a result of the integration test, it was confirmed that perpendicular recording 2.5"HDDs functioned well at the capacity of 20GB/pl and 30GB/pl.View full abstractDownload PDF (472K) -
Article type: Appendix
Pages App1-
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (72K) -
Article type: Appendix
Pages App2-
Published: June 13, 2002
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (72K)
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