• 한국진공학회:학술대회논문집
• /
• 한국진공학회 1992년도 제2회 학술발표회 논문개요집
• /
• pp.74-74
• /
• 1992

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
• /
• pp.164-167
• /
• 1988

This paper reports optical properties and hole formation of a 488nm-optimumed trilayer structure utiluzed Te-based thin films as a recording layer, and the application of trilayer to 830nm. The optical recording characteristics of metallic recording media are enhanced significantly by incoporating the metal (Al) layer into an antireflection trilayer structure. Due to the interference condition inherent in the design of the trilayer structure, reflectance from holes is ranked a low fraction. the hole formation is carried out by laser by $Ar^+$ laser(488nm). For 20nsec laser pulse duration, the hole opening threshold power of $(Te_{86}Se_{14})_{50}Bi_{50}$ trilayer is lower than that of monolayor that used in this experiments. Hole shapes of the whole sample were clean. For the application of the diode laser, the thickness of dielectric is varied by$\lambda$/4n. In order to compare the monolayer with the trilayer reflectance was measured.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.609-612
• /
• 2008

The solid immersion lens (SIL) based near-field recording (NFR) system is considered as one of the high density optical data storage system. For the NFR servo system, tracking servo control is a difficult technology to maintain extremely small gap between SIL and media within one twentieth. This is because the track pitch is decreased for increasing the recording density. In this paper, we propose disturbance observer (DOB) and internal model principle (IMP) for disturbance rejection due to eccentricity of disk. The performance of tracking controller using DOB is increased by about 85%, 94%, 97% using Q filters that have bandwidths of 50Hz, 125Hz, 250Hz, respectively. Moreover, IMP based controller is effectively reduced the residual error.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.77-80
• /
• 2001

Crystallographic and magnetic characteristics of CoCr-based magnetic thin film for perpendicular magnetic recording media were influenced on preparing conditions. In these, there is that substrate temperature was parameter that increases perpendicular coercivity of CoCrTa magnetic layer using recording layer. While preparation of CoCr-based doublelayer, by optimizing substrate temperature, we expect to increase perpendicular anisotropy of CoCr magnetic layer and prepare ferromagnetic recording layer with a good quality by epitaxial growth. CoCrTa/Si doublelayer showed a good dispersion angle of c-axis orientation $\Delta$$\theta$$_{50}$ caused by inserting amorphous Si underlayer which prepared at underlayer substrate temperature 250C. Perpendicular coercivity was constant, in-plane coercivity was controlled a low value about 2000e. This result implied that Si underlayer could restrain growth of initial layer of CoCrTa thin film, which showed bad magnetic properties effectively without participating magnetization patterns of magnetic layer. In case of CoCrTa/Si that prepared with ultra thin underlayer, crystalline orientation of CoCrTa was improved rather underlayer thickness 1nm, it was expected that amorphous Si layer played a important role in not only underlayer but also seed layer.t also seed layer.r.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
• /
• pp.277-278
• /
• 2002

Magnetron and Ion beam sputtering were used to texture the air-bearing surface of magnetic recording sliders. Flying height measurements and Laser-Doppler interferometry were used to compare the 'flyability' of textured and untextured sliders. Lubricant redistribution on the disk surface caused by slider/disk interactions was investigated using scanning ellipsometry (Surface Reflectance Analyzer (SRA)). The results show that slider surface texture causes only small changes in the flying height of sliders but reduces slider in-plane and out-of-plane vibrations. Textured sliders were found to cause less lubricant depletion on the disk surface than untextured sliders.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.435-441
• /
• 2011

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies in Korea use various track recording equipments to measure track irregularity. But this various equipments output different data due to their geometrical structure even measured at same location. In this report, the correlation of various track recording data used in Korea was reviewed.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.293-296
• /
• 1998

When the information of announcement facility is modified or added, they are recorded on a tape and then are updated manually using the cassette tape recorder at each office. But the degrade of the tone quality owing to repeated use of the tape and some recording mistakes by processing manually deteriorate the quality of service. And new services such as IN(Intelligent Network) and added functions make the announcement changed very often. Therefore the improved skill of the announcement handling is needed. This paper introduces the implementation of the TDX-10A on-line recording function of transferring voice in PCM data file and storing it in the memory of the recorded announcement facility, when message is recorded onthe fixed type of announcement facility.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.1028-1030
• /
• 2007

Mutual compensating concept between SIL(Solid Immersion Lens) and OL(Objective Lens) of NFR(Near Field Recording) is proposed, designed and manufactured to achieve a high NA and obtain a wider manufacturing tolerance. Tolerance information is present in article. An effective NA of Advanced SIL is 1.7 and adjustment between OL and SIL is carried out using our interferometer. We measured very clear RF signal using 3-axis actuator at Test bed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.552-555
• /
• 2004

The reliability issue of the probe tip/recording media interface is one of the most crucial concerns in the Atomic Force Microscope (AFM)-based recording technology. In this work, the tribological characteristics of the probe/media interface were investigated by performing wear tests using an AFM. The ranges of applied normal load and sliding velocity for the wear test were 10 to 50nN and 2 to 20$\mu$m/s respectively. The damage of the probe tip was quantitatively as well as qualitatively characterized by Field Emission Scanning Probe Microscope (FESEM) analysis and calculated based on Archard s wear equation. It was shown that the wear coefficient of the probe tip was in the order of 10$^{-4}$ ~ 10$^{-3}$ , and significant contamination at the end of the probe tip was observed. Thus in order to implement the AFM-based recording technology, tribological optimization of the probe/media interface must be achieved.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 추계학술대회논문집
• /
• pp.788-793
• /
• 2002

Hybrid type slim tilt actuator and 6-wire supported are developed for DVD recording in the optical disc drive of notebook PC, which can compensate the inclination of disc and objective lens. The hybrid actuator uses the actuating method of moving coil in the focus and track direction and that of moving magnet in the tilt direction. Comparing with 6-wire supported actuator and hybrid type actuator, we can choose an actuator for slim super combo pickup. Two actuator are designed through the modal analysis and magnetic field analysis and experimental results shows dynamic characteristics. Finally, it is verified that the actuator can compensate the disc tilt of ${\pm}0.4^{\circ}$.