• Structural Engineering and Mechanics
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• 제54권2호
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• pp.379-392
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• 2015

A number of acceleration-based damage detection methods have been developed but they have not been widely applied in engineering practices because the acceleration response is insensitive to minor damage of civil structures. In this article, a damage detection approach using the long-gauge strain sensing technology and the principle component analysis technology is proposed. The Long gauge FBG sensor has its special merit for damage detection by measuring the averaged strain over a long-gauge length, and it can be connected each other to make a distributed sensor network for monitoring the large-scale civil infrastructure. A new damage index is defined by performing the principle component analyses of the long-gauge strains measured from the intact and damaged structures respectively. Advantages of the long gauge sensing and the principle component analysis technologies guarantee the effectiveness for structural damage localization. Examples of a simple supported beam and a steel stringer bridge have been investigated to illustrate the successful applications of the proposed method for structural damage detection.

• 한국식품조리과학회지
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• 제10권4호
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• pp.412-419
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• 1994

The Contents of proximate compositions, vitamin C and minerals(Ca, P, Fe and Zn) of five Korean wild vegetables were analyzed. Twenty four cooking recipes with three of the vegetables were developed and their taste characteristics were evaluated by 12-trained panels. The five Korean wild vegetables are Cassia tora(C.t.), Lycium chinese Mill(L.c.), Trichosanthes quadricirra MIQ(T.q.), Polygonatum japonicum MORR et DECAIS(P.j.) and Articum lappa L.(A.l.). They have been known as the efficacious plants agaginst diabetes mellitus. In our previous work, their hypoglycemic effects have been studied through streptozotocin-induced diabetic rats and fed on the wild vegetables. Contents of moisture were 14~86% in the samples and L.c. showed relatively higher content of crude protein(16.4%). High level of crude fat was seen in C.t.(9.4%). Contents of vitamin C were also relatively high in the wild vegetables(14.2~42.0 mg%). Analysis of minerals revealed the high level of Ca in L.c. leaves, P in A.l. and Fe in C.t. and L.c. leaves. All of the samples contained Zn in 5.0~14.6 mg%. Twelvetrained taste panels indicated that the 24-preparations of L.c. leaves, fruites and P.j. were well accepted in taste, color and odor. Although L.c. fruit gruel, L.c. cream soup and P.j. saute were evalulated as less acceptable, their sensory scores were in 3.6~5.4 which were not undesirable. The newly developed cooking recipes of L.c. fruits and leaves showed better scores in color and texture, P.j. in texture and odor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1624-1626
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• 1999

PD in defect of solid insulation system is very harmful since It often leads to deterioration of insulation by the combined action of the discharge ions bombarding the surface and the action of chemical compounds that are formed by the discharge. PD can indicate incipient failure, so it has been used to determine degradation of insulation. In this paper. we investigated PD in defects of solid insulation by using statical method and classified PD patterns with surface discharge, electrical tree and void discharge by using Kohonen network. we used peak charge, average discharge power, average discharge current, repetition rate, skewness, kurtosis, QN of the max pulse height vs. repetition rate $H_q(n)$ for analysis and classification.

• 유공압시스템학회논문집
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• 제8권4호
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• pp.9-16
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• 2011

Because of the increasing demand on the high precision and high response of a machinery, proportional control valves are widely adopted at various application fields. This paper studies on the static and dynamic characteristics of a pilot proportional pressure control valve. An experimental apparatus including hydraulic pump, variable speed inverter, pressure and flow sensors and data aquisition system was set up. And various experiments such as P-Q-V curves, step responses due to input voltage and flow rate, hysteresis, frequency response of the proportional valve was carried out and the results are discussed.

• 제어로봇시스템학회논문지
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• 제9권4호
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• pp.270-276
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• 2003

The disturbance observer (DOB) has been widely utilized fer high precision and high speed motion control application. However, it still lacks the analysis for the robustness brought by using DOB. This paper summarizes six guidelines for the design of DOB taking into account the robustness and control performance in case of the second order system. For effectiveness of the proposed guideline, the actual implementation and experimental results of the DOB is compared in the Optical Disk Drive(ODD) servo system. In the DVD player and DVD-ROM drive, the guidelines of DOB are useful, and the disturbance rejection performance is improved under the DOB system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.388-393
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• 2004

Creep behavior of Ti had been studied in a stress from 9.8 to 29.4 MPa and temperature rang from 873K to 973K with a special reference to tertiary creep. It was found that stress exponent of Ti was larger than that of the general pure metal and the compound metal. The relationship between true strain and strain rate in tertiary creep was appeared as the equation, $ln{\dot{e}}$ = $ln{\dot{e}}_{0}$ + ${\Omega}$ e Also, Apparent activation energy of was appeared as 274.92kJ/mol by using the equation ${\dot{\varepsilon}}_{0}$ = A ${\sigma }_{0}^{\ast_0}$ exp$(-Q_{0}/RT)$

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.743-747
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• 2003

Applying simple random sampling in typical colony methods in the central area of habitat, 14 structural loci and 31 alleles in blood enzyme and other protein variations of Hu sheep population are examined. After collecting the same data of 11 loci about the 22 sheep colonies in China and other countries, it clusters the 23 sheep populations by fuzzy cluster analysis. The study proves that the phylogenetic relationship between Hu sheep population and Mongolia populations is relatively closed. This result obtained is shown to conform to the historical data.

• Wind and Structures
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• 제4권1호
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• pp.63-72
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• 2001

This paper presents results of a study on wind loads and wind induced dynamic response of bridge jointed twin-towered buildings. Utilizing the high-frequency force balance technique, the drag and moment coefficients measured in wind tunnel tests, and the maximum acceleration rms values on the top floor of towers, are analyzed to examine the influence of building's plan shapes and of intervals between towers. The alongwind, acrosswind and torsional modal force spectra are investigated for generic bridge jointed twin-towered building models which cover twin squares, twin rhombuses, twin triangles, twin triangles with sharp corners cut off, twin rectangles and individual rectangle with the same outline aspect ratio as the twin rectangles. The analysis of the statistical correlation among three components of the aerodynamic force corroborated that the correlation between acrosswind and torsional forces is significant for bridge jointed twin-towered buildings.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.882-885
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• 2002

Assessing the condition of air insulation by measuring electromagnetic wave generated in it by partial discharges gives warning of developing faults and breakdown which may give some bad effects to other thing concerned with it. Electromagnetic wave are taken from UHF antenna with 20k ~ 2GHz frequency range. The signal waveform and FFT(Fast Fourier Transform) results from UHF antenna for PD(partial discharge) generated from two different electrode(needle-plane, needle-needle) configurations are shown and it is processed by using PRPD($\Phi-q-n$ distribution) method. Cumulative pulse sequence during 100 period is compared with PRPD method. This also will show the possibility of making apparent distinction between two PD sources.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1395-1397
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• 2002

The tyrosinase gene was selected as a candidate for uncovering genetic mechanism causing 'black ear' coat color in rabbits. A PCR-SSCP detection method was established for the $881^A{\rightarrow}881^G$ mutation located in the central region of the tyrosinase gene between the CuA and CuB binding region signatures, and this was confirmed by sequencing and alignment. Fully consistent associations between the SNP and 'black ear' coat color were observed by analysis in a "black ear" pedigree and on 61 unrelated individuals. This SNP can serve as a molecular marker for use in "back ear" wool rabbit breeding.