• Journal of the Korean Society for Precision Engineering
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• v.12 no.9
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• pp.52-58
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• 1995

Conventional measurement methods for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the methods of contact with objects to be inspect, but those methods have been taken relatively much time to be inspected. Holographic interferometry which is a non-contact optical measurement method using a coherent light can overcome these demerit, and also has an advantage that the quantitative measurement of small deformation for large areas can be accomplished at a time with high precision. In this paper the comparisons of the experimental results form holographic interferometry with those from the finite element method(FEM) and the analytical solutions of the elastic equation are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.311-312
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• 2021

Measurement technology related to vocal cord disease is in a late state of technology accumulation, and electroglotograph(EGG) measuring equipment is dependent on foreign production. This paper seeks to design a wearable wireless electrical gate conductivity measurement terminal capable of easily measuring and monitoring the vibration state of the vocal cords, that is, the contact pattern of the vocal cords, which is important in vocalization.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.665-672
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• 2000

This paper described the measurement technology to analyze the partial discharge characteristics for long term aging of insulations. This system was consisted of high voltage generation and measurement part, PD detection part, digital conversion and signal processing part. We used the VXI system for digital conversion and signal processing part. In the digital conversion part, we studied the error of partial discharge magnitude and memory capacity for reading digital signal with the sampling rate. In the signal processing part, we showed the program algorithm to count pulses and read peak values of partial discharge. The allowable minimum sampling rate of digizer was decided to 250kS/s through analyzing test. We confirmed that this system was very useful in the study of $\phi-q-n$ characteristics of long term PD experiments with specimens being consisted of internal void defects and CIGRE II electrodes.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1275-1277
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• 1995

We designed and constructed an extremly high power s-band traveling wave resonator for the test of high power microwave components using 80MW pulsed klystron with $4{\mu}s$ pulse width. The 10dB directional coupler for the input power coupling was used, and the ring consists of phase shifter, tuner, H-band, and other microwave components. The designed total electrical length of the system is 10 times of the waveguide wavelength, ${\lambda}_g$=15.3cm, and the measured total insertion loss is 0.15dB. The low power test measurment showed the power multiplication of 14.69. The design goal is to achieve the peak power of 300MW, pulse width $4{\mu}s$ with 30 pulse repetition rate. In this article we discuss the treveling wave resonant ring constructed at the PAL laboratory together with the test results.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.362-362
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• 2012

Graphene-based materials have been gaining the unprecedented academic and industrial applications, due to the unique charge transport as a new kind of 2-dimensional materials. The applications incorporate electronic devices, nonvolatile memories, batteries, chemical sensors, etc. based on the electrical, mechanical, structural, optical, and chemical features newly reported. The current work employs thermal chemical vapor deposition involving H2 and CH4, in order to synthesize the 2-dimensional graphene materials. The qualitative/quantitative characterizations of the synthesized graphene materials are evaluated using Raman spectroscopy and Hall Measurements, In particular, the effect of processing variables is systematically investigated on the formation of graphene materials through statistical design of experiments. The optimized graphene materials will be attempted towards the potential applications to flat-panel displays.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.25-32
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• 2017

Most of weapon systems use aided navigation system which integrates inertial navigation and aiding sensors to compensate the INS errors increasing with the passage of time. Various aid sensors can be applied such as Global Navigation Satellite System (GNSS), radar, barometer, etc., but there might exist time delay caused by signal processing or transferring aid information. This time delay leads out-of-sequence measurements (OOSM) systems. Previously, optimal and suboptimal measurment update method for OOSM systems, where the time delay length are known, are proposed. However, previous algorithm does not guarantee the positive definite property of covariance matrix. In order to improve numerical stability for aided navigation using delayed-measurement, this paper proposes a new measurement covariance update algorithm be similar to Joseph-form in Kalman filter. Futhermore, we propose how to implement it in indirect feedback Kalman filter structure, which is commonly used in aided navigation systems, for time-delayed measurement systems. Simulation and vehicle test results show effectiveness of a proposed algorithm.

• Journal of the Korean Society of Clothing and Textiles
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• v.19 no.6
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• pp.1027-1039
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• 1995

Clothing fitness is strongly required in the apparel industry, and draping is an effective tool to increase fitness to the wearers. A more sophisticated and systematic information of the somatotype, accordingly, is necessary for better cress form design. This study was performed to provide fundamental data on middle aged women's upper torso for dress form designers and pattern makers by classifying the somatotype based on each individual's lateral view, and analyzing the characteristics of their somatotype. Data were analyzed by factor analysis, cluster analysis, analysis of variance. Factor analysis was used to 23 items from photometric measurment and cluster analysis was applied for classification of upper torso forms. Through cluster analysis using 5 factor scores, 3 somatotypes were categorized from th lateral view 1) Type I was straight somatotype in which the plumb line passes throught the lobe of the ear, the shoulder joing and the mid abdominal region laterally. This type of woman was slender and shorter than average. 2) Type II was bending somatotype in which the upper portion of upper torso is bent forward. This type of woman was taller and fatter than average. 3) Type III was swayback somatotype in which the upper portion of protruding point on the back is bent forward but the lower portion of protruding point had characteristic of turning over somatotype. This type of woman had storter length on the front and longer lenght on the back, slender type and flat chest.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.104-110
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• 1998

In automotive industries, various processes for the cost reduction have been investigated lively. As one of them, powder metallurgy becomes influential. Compared to other methods used for he manufacture of steel components the Powder metallurgy process is competitive primarily due to the small number of production steps to reach the final geometry and thereby also the energy-efficiency. In this paper, to alter present forging process into powder metallurgy process by which the automotive clutch disc spline hub is manufactured machining process, the mechanical properties of sintered materials is investigated by specimen test. Selecting the 3 kinds of materials-SMF 4040, SMF 9060 and DHP-1, their properties according to heat treatment such as carburizing -tempering and plasma-nitrodizing are compared. By result of specimen test - tensile test, compression ring test, Impacting test, measurment of hardness, and microstructure analysis - we concluded that SMF 9060 and carburizing-tempering heat treatment is an optimal material and heat treatment method for the spline hub. It will be able to reduce manufacturing cost and weight.

• Korean Journal of Microbiology
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• v.23 no.2
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• pp.129-137
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• 1985

The RK-temperate phage which infected with Bacillus cereus was isolated and the characters were investigated. The induction of RK-temperate phage from host bacterium attained by ultraviolet light irradiation (15W, 30cm, 30-120sec) and mitomycin C treatment (0.2-2 ug/ml). The host range of RK-temperate phage was not revealed with lysogenic and related strains of B. cereus. But B. cereus(PS) 352 which obtained by N-nitrosoguanidine treatment (1,000{$\mu}g/ml)$ to phage infected with host bacteria was sensitive bacteria of RK-temperate phage. RK-temperate phage was stabilized at the condition of nutrient broth (pH 7-8), Tris-buffer (pH 7-8) and ammonium buffer (pH 8-9) and Sorensen's phosphate buffer (pH 6-7), but unstabilized at other salt solutions and pH range. Also, thermostability was to $45^{\circ}C$ but unstabilized at above $50^{\circ}C$. At RK-temperate phage, the measurment values of head, neck, mid tail and end tail were 59nm, $9{\times}16nm,\;10{\times}189nm,\;and\;10{\times}14nm$ respectively. The morphology of head was regular polyhedron, and the end tail was coneate form. On the one hand, the number of capsid protein layer of tail were consist of 4, 35, and 1 at neck, mid tail, and end tail, respectively. RK-temperate phage was identified with DNA phage and G+C contents were 38.63. The latent time of RK-temperate phage was 30 minutes and the burst size was 70-80. And the host bacteria was lysed in case of multi-infection, above moi 1.

• Proceedings of the Safety Management and Science Conference
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• 2001.05a
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• pp.301-310
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• 2001

A study for the dangerous properties measurment of dust explosion was attended by the various dust concentration on Anthraquinone, Sodiumbenzoic acid, Corn starch, soy sauce powder, and cheese powder. As the result, maximum explosion pressure, the maximum rate of pressure rise, autoigntion temperature, and the water content of dust on lower limit explosion concentration was obtained as follows 1. The lower limit explosion concentration on soy sauce powder with the humidity of 65 to 90% increased by increasing the con tent of moisture, and the effect of dry air and moisture air decreased better in make of dry air. 2. The effect of a various dust concentration on autoigntion temperatures is investigated, If the vessel of dust explosion is small size and the easiness of autoignition was controled by air within the vessel, because it was better decreased air with increasing of dust concentration 3. The maximum explosion pressures of Anthraguinone, sodiumbenzoic acid, com starch, soy sauce powder, and cheese powder were 1.0g/$\ell$, 1.0g/$\ell$, 1.5g/$\ell$, 1.5g/$\ell$, and 1.5g/$\ell$, respectively, and the maximum rate of pressure rise were 0.5g/$\ell$, 0.5g/$\ell$, 1.0g/$\ell$, 1.0g/$\ell$, and 1.0g/$\ell$, respectively.