• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.2
• /
• pp.523-536
• /
• 1991

This dissertation analyzes the running mechanism of flexible and thin tape above rotating head through the numerical simulation and the experiment. The scope of analysis is confined to the phenomena of two dimensional elasto hydrodynamic lubrication between the protruded bump on a rotating cylinder and the running tape. This model is based on the elastic deformation equation of plate and shell and Reynolds equation. Finite difference method is employed as a numerical technique to calculate (1) the distribution of pressure between the running tape and rotating bump and (2) the vertical deformation of elastic thin tape over he rotating bump under hydrodynamic pressure. In numerical analyses, the effects of bump size on flying characteristics of the tape were evaluated and examined considering the influence of tension and stiffness of tape.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.1
• /
• pp.107-119
• /
• 1991

This dissertation analyzes the running mechanism of flexible and thin tape above rotating head through the experiment. The scope of study is confined to measure the vertical deformation of running tape under hydrodynamic pressure invoking phenomena of elasto-hydrodynamic lubrication between the protruded bump on a rotating cylinder ad the running tape. Experimental system is devised to measure the vertical deflection of the running tape by opto-electronical displacement gauge, which enables to detect microscopic surface deflection of high frequency. Thorough the tests of small specimens of groove and bump, the accuracy and reliability of this experimental method is confirmed and achieved an accuracy within 5%(2.mu.m) error for the microscopic deflection with high frequency. In experimental works, the effects of bump size on flying characteristics of the tape were evaluated and examined. For the vertical deformation of the running tape. the numerical results and its trend agree qualitatively with the experimental ones.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1990.10a
• /
• pp.181-185
• /
• 1990

In the present study, the following factors are analyzed systematically using the theoretical and experimental methods, which have the significant influence on the quality of VTR tape path system in order to develope the high performance and quality in VTR mechanism: 1) Vibration characteristics of the deck including the tape path sytem, 2) Modeling the global tape path, 3) Torsional vibration of the VTR drum. 4) Capstan system, 5) Tension bar, 6) Stick-slip phenomenon of the running tape.

• Journal of the Korean Society of Industry Convergence
• /
• v.7 no.2
• /
• pp.207-213
• /
• 2004

This paper describes the development of Behind-Tape-Reader (BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-AT cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and that between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.

• Child Health Nursing Research
• /
• v.8 no.3
• /
• pp.313-321
• /
• 2002

We would like to suggest the guideline of use of materials of sexual education for adolescent in school by examining the status of use of materials and by evaluating the video materials frequently used. Survey was done by enquetes on status of use of materials of sexual education from school nurses in 190 primary, 44 middle and 50 high schools in Seoul, Kyonggi-do and Kangwon-do from August 1999 to February 2000. The frequently used 84 videotapes were evaluated on their contents. As for the status of use, 99.3% of subjected schools possessed the materials for sexual education. Decision of purchase was determined according to the review of contents (92.6%). Information about materials was received by the advertisement in newspapers or broadcasting (46.1%) or recommendation of peer teacher (32.4%). Videotape was most frequently used (64.1%) rather than books or CD. Teachers concerns on the materials were the educational content according to developmental stage of students (41.9%), content provoking interest (33.5%) and concrete guide for teacher (10.6%). As for the evaluation of the contents of videotapes, a subject of education was not described out of 46.6%. Videotape producer were mostly the Government-affiliated institutes or non-profit organizations (86.8%). The year of production was indicated from 41.7%. Running time range of 21-30 minutes was highest (55.9%). The price was marked in only one videotape. Subjects of contents were general sexual education (34.5%), sexual violence or sexual harassment (21.4%), pregnancy and contraception (14.2%) and AIDS and sexually transmitted diseases (8.3%) and dating and adolescent change (4. 8%), and etc (11.9 %). According to above results, we suggested that materials for sexual education should be completed with a description on the subjected group, summary of content, information on the tape producer, year of production, running time and sale price.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.4
• /
• pp.805-815
• /
• 1994

The development of automatic production systems has a trend toward Computer Integrated Manufacturing System(CIMS) in recent years. In hardware configuration, CIMS are composed of intelligent CAD/CAM work stations, multifunction CNC machining centers including material handling systems. The DNC systems present the key element of automation hierarchy in a FMS. A DNC system is one which connects a number of numerically-controlled machines to a common memory in a digital computer for part program storage with provision for on-demand distribution of part program data to machines using communication in hierarchical structure of central computer, control computer and cell controller. This paper describes the development of Behind-the-Tape-Reader(BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-386 cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and the connection between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.

• Journal of Sensor Science and Technology
• /
• v.17 no.5
• /
• pp.329-337
• /
• 2008

Simple, small and portable oxygen sensors were fabricated by tape casting technique. Yttria stabilized zirconia containing cordierite ceramics (YSZC) were used as a porous diffused layer of oxygen in pumping cell. Yttria stabilized zirconia (YSZ) solid electrolyte, YSZC porous diffusion layer and heater-patterned ceramic sheets were prepared by co- firing method. Limit current characteristics and the linear relationship of current to oxygen concentration were observed. Viscosity variation of the slurries both YSZ and YSZC showed a similar behavior, but micro pores in the fired sheet were increased with increasing of the cordierite amount. Molecular diffusion was dominated due to the formation of large pores in porous diffusion layer. The plateau range of limit current in porous-type oxygen sensor was narrow than the one of aperture-type oxygen sensor. However limit current curve was appeared in porous-type oxygen sensor even at the lower applied voltage. The plateau range of limit-current was widen as increasing the thickness of porous diffusion layer of the YSZ containing cordierite. Measuring temperature of $600{\sim}650^{\circ}C$ was recommended for limit-current oxygen sensor. Porous diffusion layer-type oxygen sensor showed faster response than the aperture-type one and was stable up to 30 days running without any crack at interface between the layers.