• Proceedings of the Korean Vacuum Society Conference
• /
• 2002.06a
• /
• pp.136-136
• /
• 2002

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.3
• /
• pp.27-32
• /
• 2002

• Journal of Mechanical Science and Technology
• /
• v.20 no.7
• /
• pp.961-971
• /
• 2006

A deadweight force standard machine is a mechanical structure that generates force by subjecting deadweights to the local gravitational field. The Korea Research Institute of Standards and Science (KRISS) developed and installed a 100 kN deadweight force standard machine for national force standards. It can generate forces from 2 kN to 110 kN in increments of 1 kN. The uncertainty of the force machine was estimated and declared as $2\times10^{-5}$. This 100 kN deadweight force machine was compared with the 500 kN deadweight force standard machine at KRISS and the 20 kN and 50 kN deadweight force standard machines at the National Metrology Institute of Japan (NMIJ). The measurement results showed good agreement between the deadweight force machines, and the accuracy level of the 100 kN deadweight force machine was verified.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.3 s.174
• /
• pp.667-675
• /
• 2000

Force measuring devices should be calibrated to guarantee their test results. In order to establish the force standards in Korea, deadweight machines of 5 kN, 20 kN, 100 kN and 500 kN capacity and a hydraulic force standard machine of 2 MN capacity were installed at the Korea Research Institute of Standards and Science(KRISS). As heavy industries in Korea have been developed, we should measure large forces over 2 MN capacity precisely in industries. We developed a 10 MN force standard machine with built-in force transducers which is more compact and cheaper than hydraulic force standard machines which have been widely used as large force standards in most national metrology laboratories. Test results reveal that the relative expanded uncertainty of the force machine is less than 4.1 $\times$ 10-4 in the range of 1 MN-4.5 MN.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.59-62
• /
• 2005

Small force measurements ranging from 1 pN to $100{\mu}N$, we call it Nano Force, become the questions of common interests of biomechanics, nanomechanics, material researches, and so on. However, unfortunately, quantitative and accurate force measurements have not been taken so far. This is because there ,are no traceable force standards and a calibration scheme. This paper introduces a quantitative force metrology, which provides traceable link to SI (International Systems of Units). We realize SI traceable force ranging from 1 nN to $100{\mu}N$ using an electrostatic balance and disseminate it through transfer standards, which are self-sensing cantilevers that have integrated piezoresistive strain gages. We have been built a prototype electrostatic balance and Nano Force Calibrator (NFC), which is an AFM cantilever calibration system. As a first experiment, we calibrated normal spring constants of commercial AFM cantilevers using NFC. Calibration results show that the spring constants of them are quite differ from each other and nominal values provided by a manufacturer (up to 240% deviation).

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.3
• /
• pp.477-484
• /
• 1997

This paper describes the build-up force measuring system of 9.9 MN capacity which consists of nine force transducers of each having 1.1 MN capacity. We have specially designed a force transducer for a build-up force measuring system to reduce the uncertainty of a build-up system and to accomodate the new test procedure for a build-up system. It reveals that the relative uncertainty of the force measuring system is less than 1.5*10$^{-4}$ in the ran9e of 1-4.5 MN irrespective of loading direction. The force measuring system may be used to calibrate a 10 MN force standard machine to be used as a large force standard in Korea.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.3
• /
• pp.13-18
• /
• 2002

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.3
• /
• pp.7-12
• /
• 2002

• Journal of the Korean Society for Library and Information Science
• /
• v.12
• /
• pp.121-147
• /
• 1985

In the modern communicative age, the standards of the school libraries are the qualitative guarantee on the services of school libraries or school library media programs, as the guidline, the active guide, the policy documentation and criteria for the professional excellence. The standards of SLMP were revised the sixth time by the school library profession(ALA) with the members or agency of NEA in the U.S. There are the first standard was a quantitative; 'the Certain Report'(by A.L.A., 1920) appearing that the school library is the heart of the school, 2nd 1925; turning up the teaching material source and personel, 'School Libraries for today and tomorrow' (by AASL, 1945) incluseing the instructional materials and the 7th educational ideas in the quantitative feature, 'Standards for School Library Programs' (by AASL, 1960) expressing the instructional material center, communicative environment, learning and teaching laboratory, 'Standards for school media programs' (by DAVI & AASL, 1969) implicating the instructional resource, learning and teaching laboratory, the condition precedent of qualitative education for excellence, 'Standards for media programs; District/school (by AASL & AECT, 1975) containing the improving user's educational experience and personal freedom on the use of SLMP's services. Through changing the standards of SLMP in the US, We have known that the main educational idea in the standards are; (1) SLMP is the instructional force and resource for qualitative, excellence education by learning and teaching laboratory, instructional resource, communicative environment (2) SLMP is the actualizing force and resource for user's self-realization by intellectual and personal excellence, individualizing, humanizing and personalizing education.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.359-359
• /
• 2014

In this study, surface plasmon resonance structures for the selective and the enhanced transmission of infrared light were designed. In order to relieve the large discontinuity of refractive index between air and metal hole array, $Si_3N_4$ was used as the impedance matching layer. Experimental parameter were calculated and determined in advance by the rigorous coupled wave analysis (RCWA) simulation, and then the experiment was carried out. A 2-dimensional metal hole array structures were patterned on the size of $1{\times}1cm^2$ GaAs substrate using photolithography process, and 5 nm thick Ti, 50 nm thick Au were deposited by E-beam evaporator, respectively. Subsequently, $Si_3N_4$ films with various thicknesses (150, 350, 550, and 750 nm) were deposited by plasma enhanced chemical vapor deposition (PECVD). For the comparison, transmittance of specimens with and without $Si_3N_4$ was measured using Fourier transform infrared spectroscopy (FTIR) in the range of $2.5-15{\mu}m$. Furthermore, the surface and the cross-sectional images were collected from the specimens by scanning electron microscopy (SEM). From the results, it was demonstrated that the transmittance was enhanced up to 80% by the deposition of 750 nm $Si_3N_4$ at $6.23{\mu}m$. It has advantage of enhanced transmission despite the simple fabrication process.