• Journal of the Korean Society for Precision Engineering
• /
• v.7 no.3
• /
• pp.75-82
• /
• 1990

Automatic monitoring of the cutting conditions is one of the most improtant technologies in machining. In this study, the feasibility in applying acoustic emission(AE) signals for the in-process detection of endmill wear and fracture has been investigated by performing experimental test on the NC vertical milling machine with SM45C for specimen. As the results of detecting and analyzing AE signals on various cutting conditions, the followings have confirmed. (1) The RMS value of acoustic emission is related sensitively to the cutting velocity, but is not affected largely by feed rate. (2) The burst type AE signals of high level have been observed when removing chips distorderly and discontinuously. (3) When the RMS value grows up rapidly due to the increase of wear the endmill are generally broken or fractured, but when the endmills fracture at the conditions of smooth chip-flow or built-up-edge(BUE) occurred frequently, the rapid change of the RMS arenot found. And it is expected that this technigue will be quite useful for in-process sensing of tool wear and fracture.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1954-1956
• /
• 2000

In this paper, when void of XLPE was existed, electrical tree was growth in branch-type, and it was growth in bush-type when void of XLPE was not existed. Moreover, charge magnitude of partial discharge by deterioration time of XLPE sample was about proportion to output voltage of AE signals. When void was existed, charge magnitude of partial discharge, the output voltage Vp-p value of AE signals were increased with increasing deterioration time. However, when void were not existed, charge magnitude of partial discharge, the output voltage Vp-p value of AE signals were increased in fast deterioration time, but it were decreasing at after in middle deterioration time. Frequency spectrum response of AE signal was about 100-250[kHz].

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.5
• /
• pp.938-946
• /
• 1989

Using the CT specimen of carbon steel(SM45C), we estimated the fatigue crack propagation behavior in stable crack propagation range. Furthermore the fatigue crack propagation rate, Acoustic Emission(AE) count rate, and fractography characteristics were also compared among others. The following results were confirmed by experimental observation. Near-threshold stress intensity factor range(.DELTA. $K_{th}$) is influenced by stress ratio but not at the upper limit of stable crack propagation range. As stress intensity factor range(.DELTA.K) and(or) stress amplitude increase (s), both crack propagation rate(da/dN) and AE count rate(dn/dN) increase. Effective stress intensity factor range(.DELTA. $K_{off}$) determined from the crack closure point measurement by AE method is useful for the evaluation of fatigue crack propagation rate. Fractography in stable crack propagation range showed striation, and agreed with the crack propagation rate obtained either by experiment of by the results of microscopic measurements.s.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1404-1407
• /
• 2004

An electric railway system is composed of high-tech subsystems, among which main electric equipments such as transformers, converter and traction motors are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of Korean High Speed Train. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the measurement system. By using the system, measurement and evaluation for the performance of electric equipments in Korean High Speed Train was conducted during test running.

• Fashion & Textile Research Journal
• /
• v.4 no.2
• /
• pp.163-168
• /
• 2002

For the purpose of investigating the factor of foot and calf growth of primary-school children who are fast-growing during this period a group of the 1st graders of primary-school had been the subject of this measurement in 1995 and there after they became the subject again in 1997, 1999 when they were the 3th, 5th graders measurement was carried out in 30 items including status and weight and marthin-type measure and foot-print were used for this measurement as the result, stature is correlated with height items and length items of foot and calf weight is correlated with width and circumference items of foot and calf angle of the first toe showed the highest growth like 3rd graders, heel circumference had rapidly grown rather than in the part of foot circumference in the factor analysis df foot measurement of 10-year, the first, second factors, appeared the size of shoes, in case of 12-year the first factor with status appeared the size of shoes.

• Journal of Sensor Science and Technology
• /
• v.14 no.3
• /
• pp.169-179
• /
• 2005

A multiplexed bend loss type single-mode fiber-optic sensor system was prepared to measure the displacement of several cm of the civil engineering structures such as many bridges, tunnels and various buildings. This bend loss type fiber-optic sensor used the signal difference between two reflection signals due to various bend losses generating at a pair of optical connectors by using OTDR (optical time domain reflectometer) for measuring displacements. And the experiments were conducted for showing the measurement feasibility on the range of 10 cm, and the multiplexing experiments were also performed to measure the displacements of 5 measuring positions of an object by setting these 5 fiber-optic sensors on a single mode fiber simultaneously.

• Proceedings of the Korean Nutrition Society Conference
• /
• 2003.05a
• /
• pp.124.2-124.2
• /
• 2003

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.531-532
• /
• 2009

• Proceedings of the Optical Society of Korea Conference
• /
• 2004.02a
• /
• pp.254-255
• /
• 2004

• Journal of Korean Medicine Rehabilitation
• /
• v.28 no.1
• /
• pp.33-51
• /
• 2018

Objectives The purpose of this study is to analyze the current status of measurement instruments used to evaluate pain and function for shoulder disease patients in Korean Medicine clinical studies published in South Korea. Methods 5 Korean online databases from January 2007 to July 2017 were used to source articles for the review. Data of pain and function assessment instruments, measurement methods, time point and frequency for shoulder assessment were extracted. And it was analyzed by investigating the frequency of use for each item. Results A total of 78 studies met the selection criteria. There were many studies with no description for pain assessment instruments or inconsistent measurement methods. In the function assessment, the frequency of use was low and there were a lot of use of instruments with low validity and reliability. Conclusions To develop the objectivity of clinical research, further clinical studies, active use of measurement instruments, and standardization of measurement methods are needed.