• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.241-242
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1055-1056
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1081-1082
• /
• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.679-680
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.529-530
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.115-116
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.729-730
• /
• 2010

• Journal of international Conference on Electrical Machines and Systems
• /
• v.2 no.4
• /
• pp.486-490
• /
• 2013

A defect which is axially oriented with small size is hard to detect in conventional system. CMFL(Cricumferential Magnetic Flus Leakage) type PIG(Pipelines Inspection Gauge) in the NDT(Nondestructive Testing), is operated to detect this defect called axially oriented cracks in the pipe. It is necessary to decompose the size and shapes of cracks for the manintenance of underground pipelines. This article is focused on the decomposing method of the size and shape of the axially oriented cracks by using inspection signal data for defect.

• Transactions on Electrical and Electronic Materials
• /
• v.18 no.2
• /
• pp.70-73
• /
• 2017

We investigated n-i-p type single junction hydrogenated amorphous silicon oxide solar cells. These cells were without front surface texture or back reflector. Maximum power point efficiency of these cells showed that an optimized device structure is needed to get the best device output. This depends on the thickness and defect density ($N_d$) of the active layer. A typical 10% photovoltaic device conversion efficiency was obtained with a $N_d=8.86{\times}10^{15}cm^{-3}$ defect density and 630 nm active layer thickness. Our investigation suggests a correlation between defect density and active layer thickness to device efficiency. We found that amorphous silicon solar cell efficiency can be improved to well above 10%.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.635-636
• /
• 2012

In the present work, investigations by high frequency resonance technique for diagnosis of defect frequencies of linear motion unit are reported. Raw vibration signature of the moving parts at different speeds of operation has been demodulated. Envelope detected spectrum is analyzed to evaluate various defect frequencies and their energy levels. Experimentally evaluated frequencies are compared with theoretically determined defect frequencies. These frequency values and their energy levels are used to monitor intrinsic condition of linear motion unit as well as to establish severity of existing/developed defects on the LM guide and inside the LM block. Relative comparisons of linear motion units of the same type are made at various operating speeds under identical conditions of operation on the basis of identified defect frequencies and severity of defects.