• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.287-288
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• 2013

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.87-90
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• 2005

An experimental investigation of the basic characteristics of a micro-cantilever sensor was performed by inspecting the amplitude and frequency characteristics using a commercial tuning fork. Application of acetone and ethanol with a volume of $1 {\mu}l$ on the tine of a vibrating tuning fork cause immediate response in its amplitude and frequency. It has shown that the tuning fork has ability to recognize a chemical agent with high sensitivity.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.124-129
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• 2018

A forklift is used to lift materials above a height of 2 m. The width of the fork determines the weight of the material it can carry. In this paper, three models of fractured forklifts were analyzed to determine if the fracture was caused by load fatigue due to the width of the fork. The position of the fork was fixed on each model, and a 2.5 ton load was placed at the upper part of the fork. The width distances on each of three models were 500 mm, 750 mm and 1000 mm, and the maximum equivalent stresses were 237.5MPa, 227.62MPa and 230.99MPa, respectively. This analysis demonstrated that as the load increased with use of the wider fork, the fatigue life remained to be nearly equivalent irrespective of fork width among all three models. The results of this study contribute to the durability and safety design of forklifts.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.75-82
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• 2016

According to the statistics, occupational fatal injuries by the fork lifts were about 30 per year in whole industrial. Fork lifts are widely used in various parts of industries to improve the efficiency of the work. In this study, the current regulations to be adequate in industrial site have to be renew in order to prevent the fatal injuries by the fork lifts. Fatal injury analysis were conducted with several accident cases by the fork lifts. For each accident, the causes of the injuries were examined and proper safety measures were proposed. In this study, the fork lift showed a high fatality rate in industrial accidents and no detailed cause analysis of fatal accidents was conducted in terms of unsafe acts or conditions. First, fork lifts were the highest of the machines caused the accidents. In order to prevent fatal injuries by the fork lifts, the tarket was manufacturing industry. Second, the order of the cause of cognitive engineering agenda in the manufacture industrial was visibility, responsibility and affordance, and revision of acts was proposed. Third, there was not a lots of different points of human error between occurrence types and business sizes. Forth, number of fatalities by the attacker was more than by the inducer.

• Journal of information and communication convergence engineering
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• v.14 no.2
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• pp.65-70
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• 2016

This paper proposes and experimentally tests a modified circular slot antenna fed by a fork-like tuning stub for ultra-wideband (UWB) operation. The proposed antenna consists of a modified circular slot model and fork-like tuning stub. The proposed antenna is printed on a 34.0 mm × 30.0 mm FR4 substrate with thickness of 1.0 mm and relative permittivity of 4.4. The effect of various parameters of the circular slot and fork-like tuning stub is investigated for UWB operation. The modified circular slot and fork-like tuning stub are fabricated on the substrate to achieve wideband operation and good impedance matching. Experimental results demonstrated that the measured return loss exhibits an acceptable agreement with the simulated return loss and satisfies the -10 dB impedance bandwidth requirement while simultaneously covering the UWB bands. In addition, the proposed antenna shows good radiation characteristics and gains in the UWB bands.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.86-91
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• 2007

A sensor using quartz toning fork is presented for measuring liquid density. It consists of a PZT plate as an actuator for piezoelectric excitation and a quartz tuning fork as a sensor for resonant frequency detection. The resonant frequency is determined from the sensing voltage measured in tuning fork when the excitation frequencies of PZT actuator are swept around the resonant frequencies of tuning fork. The resonant frequency determined the liquid density. The density values of three kinds of organic solvents are measured and compared with the standard values. The experimental results are in agreement with the standard values and the maximum standard deviation is less than 9%.

• Journal of architectural history
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• v.27 no.1
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• pp.17-28
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• 2018

This study researches the relationship between the Folk houses in Heung Yang-islands and the Ulleung-island Folk Houses in Modern Age. Fork houses reflect cultural and geographical features synthetically and concretely. Fork houses contain the thoughts of residents and have been built rationally and economically, therefore studying fork houses is a very meaningful task. This study has a focus on the elements which influenced fork houses of Ulleungdo at the time when fork houses were constructed officially. There have been studies on fork houses of Ulleungdo limited in embrasive characteristics, space construction and arrangement. So, the purpose of this study is to investigate about the element and background of Ulleung-island Folk Houses in Modern Age.

• Journal of Sensor Science and Technology
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• v.24 no.2
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• pp.93-95
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• 2015

We present an optical detection method for the fundamental vibrational mode of a tuning fork crystal oscillator in air. A focused He/Ne laser beam is directed onto the edge of one vibrating tine of the tuning fork; its vibrating motion chops the incoming laser beam and modulates the intensity. The beam with modulated intensity is then detected and converted to an electrical signal by a high-speed photo-detector. This electrical signal is a sinusoid at the resonant frequency of the tuning fork vibration, which is 32.76 kHz. Our scheme is robust enough that the sinusoidal signal is detectable at up to $40^{\circ}$ of rotation of the tuning fork.

• Journal of Magnetics
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• v.16 no.3
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• pp.271-275
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• 2011

This paper proposes a magnetoelectric (ME) composite transducer structure consisting of a magnetostrictive H-type Fe-Ni fork substrate and piezoelectric PZT plates. The fork composite structure has a higher ME voltage coefficient compared to other ME composite structures due to the higher quality (Q) factor. The ME sensitivity of the fork structure reaches 12 V/Oe (i.e., 150 V/cm Oe). The fork composite with two PZT plates electrically connected in series exhibits over 5 times higher ME voltage coefficient than the output of the rectangle structure in the same size. The experiment shows the composite of a Fe-Ni fork substrate and PZT plates has a significantly enhanced ME voltage coefficient and a higher ME sensitivity relative to the prior sandwiched composite laminates. By the use of a lock-in amplifier with 10 nV resolution, this transducer can detect a weak magnetic field of less than $10^{-12}$ T. This transducer can also be designed for a magnetoelectric energy harvester due to its passive high-efficiency ME energy conversion.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.401.2-401
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• 2002

An unconstrained tuning fork with a 3-D model has been numerically analyzed by Finite Element Method (FEM) and Boundary Element Method (BEM). The first three natural frequencies were calculated by the FEM modal analysis. Then the change of the modal frequencies was examined with the variation of the tuning fork length and width. (omitted)