• Journal of IKEEE
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• v.18 no.4
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• pp.625-629
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• 2014

This study derives the asymptotic phase noise formula of the oscillators perturbed by the colored noises. Based on the derived formula, this study presents a sub-1V series-tuned differential Colpitts VCO. The ADS simulation result on the phase noise shows that the presented VCO exhibits about 3dBc/Hz lower phase noise at the 1MHz offset frequency from the oscillation frequency of 4.8GHz than the existing series-tuned differential Colpitts VCO with the inductor current sources.

• The Research Journal of the Costume Culture
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• v.11 no.2
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• pp.263-274
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• 2003

This study analyzes how social environment influenced underclothes and characteristic which underclothes have is associated with the outer garment and the underclothes in the Middle Ages. As a result, 1 can get the next conclusion First, throughout the Middle Ages, body was involved with the sense of same and sin influenced by the religious austerity. This mentality was applied to the underclothes. As underclothes are not generally revealed, it is recognized to be not important but inefficient. Second, in the late Middle Ages, as the outer garment reveal the body line, the underclothes are affected by it. So men's and women's distinction in the outer garment is applied to the underclothes. In the second quarter of the 14C, class distinction and sexual attraction certainly present on the outer garment but are not applied to the underclothes. The conceptions that underclothes might express the spirit of the changing times, in sympathy with the outer garment, did not enter the medieval mind. Third, the function to protect the body is emphasized the underclothing in the Middle Ages, whereas it was important to identify rank sign in the history of underclothes. Throughout the Middle Ages the underclothing of both sexes is emphasized utilitarian in (unction rather than class distinction and sexual attraction. But women exposed their body line in thin chemise to represent sexual attraction in the late Middle Ages.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.2
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• pp.67-79
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• 2012

As credit cards are more convenient than cash of heavy and volume, they are used widely in on_line (internet) and off_line in nowadays. A head of the economically active population had 4.8 credit cards in the third quarter 2011. The economically active population in their 20's and 30's may have more than 10 credit cards. If the membership card and point card are included, the count rise to 20 cards in a man. Therefore, the their purse become thick by several cards. Nowadays, the smart-phone is widely used. Therefore, a lot of credit cards are come in smarty-phone from analog form to digital form. In this paper, we study a method of digital credit cards management in smart-phone. For the method, the hardware need in small and existing system have a few change. All kinds of credit cards are used in smarty-phone. We compare the method with Moneta card and NFC of smarty-phone. The digital credit cards feature a light, safety and convenience of mobile users in several ways.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.5
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• pp.625-634
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• 1986

The strain distribution on a welded aluminum alloy transition joint produced by a static tensile load has been measured using a moire method combined with photoelastic coating method. The test specimens were made of aluminum alloy 6061-T6 and 2014-T6 butt welded with ER-4043 filler metal, and were post welded heat treated (solid solution heat treatment 502.deg. C 70min.) and precipitated (artificial aging 171.deg. C 600min.) to cause an abrupt change of mechanical properties between the base metals and weld metal. The photoelastic epoxy rubber was cemented on the specimen grating which had been reproduced on the specimen surface by using an electropolishing. The measurements were compared with strains computed by Finite Element Analysis. The following results were abtained. (1) The maximum strain were distributed along the center line in the transverse directiion of the weld metal. (2) The strain gradient along the fusion line increased approaching the V-groove tip and the maximum value was observed at a quarter of width from the V-groove tip. (3) The moire method combined with photoelastic coating was proved very useful for real time strain measurement in the welded aluminum alloy transition joint.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.87-97
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• 1998

This paper describes an analysis of tunable characteristic for magnetically tunable E-plane type finline filter on a ferrite substrate. The proposed design is based on using of quarter wavelength transmission line for compensating the negative length transmission line of end K-inverters of E-plane type waveguide filters and the tunable characteristics of designed filters are analyzed. The analysis results of filter and inverter structure loaded with finline on a ferrite substrate are obtained using the edge based finite element method including higher order mode effects. The X-band experimental results for bilateral and unilateral finline magnetically tunable E-plane type waveguide filters agree well with the simulated data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.97-103
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• 2000

In this paper band-stop filters that reject the undesired 3th and/or 5th harmonics generated from high frequency generator are analyzed using equivalent circuit concept, and optimized using iterative optimization algorithm. The length of the band-stop filter is setup initially a quarter of a wavelength of the harmonic, but initial filter structure is exactly unable to cutoff the harmonics because of the fringing effect at the discontinuous boundary. To reduce the mismatch between the cutoff frequency and the harmonics, iterative LMA(Levenberg-Marquardt Algorithm) is introduced and band-stop filters in coaxial line are optimized.

• The Journal of Advanced Prosthodontics
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• v.3 no.2
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• pp.69-75
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• 2011

This study assessed the effect of preparation design on marginal adaptation and also compared the sensitivity and specificity of clinical evaluation techniques for marginal accuracy of cast restorations to stereomicroscopy. MATERIALS AND METHODS. Three Ivorine molar teeth of different designs were prepared. (A)-A complete crown preparation with buccal shoulder and beveled finish line. (B)-A complete crown preparation with chamfer finish line. (C)-A three-quarter crown preparation with proximal boxes and beveled finish line. Twenty four castings were prepared with eight castings for each design respectively. Each casting underwent examination with an explorer, disclosing media, and a stereomicroscope. Stereomicroscopy at a value less than or equal to 30 microns was used as a gold standard to evaluate the significance of different designs on marginal adaptation. Chi-square tests of independence and Kruskal-Wallis were used to evaluate the effect of preparation design and compare the agreement between examination methods for detection of marginal gap size of greater than or equal to 30 microns (${\alpha}$=.05). Sensitivity and specificity for explorer and disclosing media as compared to stereomicroscope was calculated using statistical formula given by Park. RESULTS. The preparation design did not significantly affect overall marginal adaptation. Examination by explorer and disclosing media at $30 \;{mu}m$ revealed 39% and 10.06% sensitivity and 91% and 82% specificity respectively. CONCLUSION. Preparation designs examined in this study did not significantly affect the marginal adaptation of the castings. Commonly used clinical evaluation techniques using explorer and disclosing media appeared to be inadequate for assessment of marginal accuracy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.12
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• pp.931-939
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• 2013

In this paper, we try to find the lifting-line method which is applicable to the conceptual design of aircraft wings, and analyze the accuracy and coverage of the method. Two methods that are extended from the lifting-line theory of Prandtl are selected. One of the methods is Weissinger's method which imposes the velocity boundary condition at the control points located at the quarter chord, and the other is Phillips's method which combines the three-dimensional vortex lifting law. Calculations are performed for an elliptic wing, a swept back wing, and a tapered unswept wing with dihedral angle and geometric twist. The aerodynamic data of the potential flow such as spanwise distributions of circulation and downwash, lift and induced drag are obtained through calculations, and these data are compared with theoretical results and wind tunnel test data. As a result, Weissinger's method showed good accuracy and reliability regardless of wing shapes, but Phillips's method revealed inaccurate results for a swept back wing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1048-1057
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• 2012

In this paper, a new compact dual-band unequal power divider is suggested. Instead of the quarter wavelength transmission line(TX-line)s for the branches of the conventional Wilkinson's power divider, we use composite right- and left-handed(CRLH) phase-shift lines and can reduce the physical length. With the non-linear dispersion of the meta-meterial, each branch in the proposed divider is designed to have $+90^{\circ}$ and $-90^{\circ}$ at $f_1$ and $f_2$ respectively. To validate the proposed method, the performances of the circuit and full-wave simulation results are shown with the CRLH dispersion curve. The measurement results are compared with the simulation results. Also, the size reduction effect by the proposed scheme is addressed.

• Korean Institute of Interior Design Journal
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• v.13 no.3
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• pp.129-136
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• 2004

The purpose of this study is to provide basic information and guide line for designing hotels located in metropolis by analyzing the spatial configuration of public area. As the sample of analysis, ten hotels are selected in Tokyo area, which were constructed during 1970 to 1990; the period was characterized by booming hotel constructions. The findings of the above analytical survey might be summarized as follows. First of all, it was found that all hotels constructed during the above mentioned periods could be classified into two categories according to their block type such as interlocking form and form within form types. It also observed the six hotels out of then had adopted form within form, beside, the left four hotels were constructed along the interlocking form type. Secondly, as regard to the functional space configuration of the public area, it was found that, in case of eight hotels, the upper part of the building which allocated as residential quarter are configured as linear type. As regard the lower part, however, it was found that different types are adopted. For instance, five hotels had adopted con-course types for the lower level that is spared for the public/service area. Beside, it was also found that, out of above five hotels, three hotels took form within type and the other two adopted compromising type. Thirdly, as regard to the composition of public area, it was found that, the quarters are allocated as follows, such as 34.11 percent for public, 28.99 percent for sales and 33.07 percent for service quarter.