• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.115-122
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• 2005

As the digital TV markets rapidly growing, many manufacturers introduce large size flat screen TV units. There are two different display types available to large size models which are plasma and TFT-LCD. Since both are constructed with thin large panels that are mostly fragile to even moderate mechanical shock inputs. Some large size panels are severely resonated by the acoustic sound generated TV which deteriorates video quality. Recognizing the potential problems of large displays, accurate measurement of the panels is to be an essential task for the reliable design. Measurement of mechanical properties of a thin large crystallized panel such as TFT-LCD display with traditional material testing equipments is challenging. Since TFT-LCDs are constructed with combination of brittle glass panels, polymer sheets, and liquid crystal, their properties are not only anisotropic but also usually non-linear. Accurate measurement of the properties often requires very expensive facilities. Especially when the size of the test sample is as large as 40-inch or wider, direct measurement cost is prohibitive. Even worse, machining of the large TFT-LCD to make a smaller size specimen that could be fit into a material tester is not possible because of liquid crystal leakage. A new method fer the measurement of elastic modulus of large TFT-LCD panel is presented in this article. The suggested method provides a simple, economic, and user-friendly way fer measuring the elastic modulus of large panels with considerable level of accuracy.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.183-188
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• 2005

Defect on the temporal area caused by, surgical ablation of a tumor or an infection should be reconstructed immediately to prevent potentially life-threatening complications such as meningitis and cerebrospinal fluid leakage. The defect on the temporal area usually presents as a typical 'cone-shape'. Successful reconstruction requires sufficient volume of well-vascularized soft tissue to cover the exposed bone and dura. From 1994 through 2003, the authors applied rectus abdominis free flap for the reconstruction of the temporal defect from 1994 through 2003. There were 10 patients with a mean age of 52.1 years. Of these 10 patients, external auditory canal cancer was present in four patients, temporal bone cancer in two, parotid gland cancer in one and three patients were reconstructed after debridement of infection(destructive chronic otitis media). All the free flaps survived, and flap-related complications did not occur. Compared to a local flap, the rectus abdominis free flap can provide sufficient volume of well-vascularized tissue to cover the large defect and can be well-tolerated during an adjuvant radiation therapy. The long and flat muscle can be easily molded to fit in to the 'cone-shape' temporal defect without dead space. It is also preferred because of the low donor site morbidity, a large skin island and an excellent vascular pedicle. Two-team approach without position change is possible. In conclusion, the authors think that rectus abdominis free flap should be considered as one of the most useful method for the reconstruction of a cone-shaped temporal defect.

• Journal of the Korean Society of Costume
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• v.45
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• pp.103-120
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• 1999

The purpose of the study is to show concretely the design features due to cltohes image after classifying the clothes image examining relations between clothes images and design factors. Samples of the study were 507 female university students. Materials of the study were 309 slide film using the spring and fall issues of magazines and catalogues in 1996 and 1997. SAS PC was used to analyze materials and finally priniciple component analysis the analysis by quantification theory 1. The results of the study were as follows. The most important images of clothes were fashion dignity activation and simplicity. In the relationship between the main image and item factor, one-piece jumper half-coat culotte skirt pantaloons and slim pants had an important effect on the fashion image while two-piece jacket, blouse, straight pants had an effect on the dignity image and three-pice, T-shirt, shirt-vest pantaloons normal pants culoote skirt and gather skirt strengthen active image. In the relationship between the main image and silhuette X-silhouette fitting upper and lower clothes upper clothes having waist line or hip bone length and mini-skirt were the factors that raisen fashion image. And in the A-, X-, Y-silhouette having normal fit upper clothes below the knee length skirt and the upper clothes below the hip line were main factors in dignity image. And H-silhouette big size sleeves mini-skirt the upper clothes below hip line were the factors that strengthened the active image. In the relationship between fashion image and detailed factors roll stand and sports collar set-in and shirt sleeves having 5-rate and long sleeves strengthened fashion image. And flat tailored collar boat and high nceckline and bow detail set-i sleeve had an important effect on the dignity image. And shirt collar boat and V-neckline shirt dolman and 7-rate sleeves were the factors that raise active image.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.10 s.103
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• pp.1177-1185
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• 2005

This paper investigates the noise radiated by a cascade of flat-plate airfoils interacting with homogeneous, isotropic turbulence. At frequencies above the critical frequency, all wavenumber components of turbulence excite propagating cascade modes, and cascade effects are shown to be relatively weak. In this frequency range, acoustic power was shown to be approximately proportional to the number of blades. Based on this finding at high frequencies, an approximate expression is derived for the power spectrum that is valid above the critical frequency and which is in excellent agreement with the exact expression for the broadband power spectrum. The approximate expression shows explicitly that the acoustic Power above the critical frequency is proportional to the blade number, independent of the solidity, and varies with frequency as ${\phi}_{ww}(\omega/W$), where ${\phi}_{ww}$ is the wavenumber spectrum of the turbulence velocity and W is mean-flow speed. The formulation is used to perform a parametric study on the effects on the power spectrum of the blade number stagger angle, gap-chord ratio and Mach number. The theory is also shown to provide a close fit to the measured spectrum of rotor-stator interaction when the mean square turbulence velocity and length-scale are chosen appropriately.

• Wind and Structures
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• v.30 no.2
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• pp.181-198
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• 2020

In the traditional buffeting response analysis method, the spanwise incomplete correlation of buffeting forces is always assumed to be same as that of the incident wind turbulence and the action of the signature turbulence is ignored. In this paper, three typical bridge decks usually adopted in the real bridge engineering, a single flat box deck, a central slotted box deck and a two-separated paralleled box deck, were employed as the investigated objects. The wind induced pressure on these bridge decks were measured via a series of wind tunnel pressure tests of the sectional models. The influences of the wind speed in the tests, the angle of attack, the turbulence intensity and the characteristic distance were taken into account and discussed. The spanwise root coherence of buffeting forces was also compared with that of the incidence turbulence. The signature turbulence effect on the spanwise root coherence function was decomposed and explained by a new empirical method with a double-variable model. Finally, the formula of a sum of rational fractions that accounted for the signature turbulence effect was proposed in order to fit the results of the spanwise root coherence function. The results show that, the spanwise root coherence of the drag force agrees with that of incidence turbulence in some range of the reduced frequency but disagree in the mostly reduced frequency. The spanwise root coherence of the lift force and the torsional moment is much larger than that of the incidence turbulence. The influences of the wind speed and the angle of attack are slight, and they can be ignored in the wind tunnel test. The spanwise coherence function often involves several narrow peaks due to the signature turbulence effect in the high reduced frequency zone. The spanwise coherence function is related to the spanwise separation distance and the spanwise integral length scales, and the signature turbulence effect is related to the deck-width-related reduced frequency.

• Science of Emotion and Sensibility
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• v.6 no.1
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• pp.17-26
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• 2003

With rapid expansion in e-retailing of apparel business, the virtual fitting model is used for comparing fit of the selected garments. The researchers experimented women's perceived body size for developing virtual fitting model. 50 women who were 20's in age were participated in the experiment They were graduate students with clothing & textile major. The results of this study showed that the subjects perceived themselves with fuller figure at waist or hips and with shorter figure at waist height than their actual body site. Many subjects believed that their body sizes were close to the average site. Especially, subjects whose abdomen girth of hip girth was much larger than average thought that they have relatively flat abdomen. It was concluded that not only the user's body measurements but also user's perception on their figure type are needed to be considered in the process of developing virtual fitting model for e-retailing of apparel. It was expected that the virtual fitting model of extraordinary size body would not be accepted by the female consumers even though they are extra large or small size person in reality.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.1
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• pp.65-72
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• 2016

In this study, a fully active transfemoral prothesis with a knee joint is designed considering stair walking conditions. Since the torque at the knee joint required for stair walking condition is relative high compared with the one in normal walking condition, the proposed design has high torque generating mechanism. Moreover, the transfemoral prothesis is designed in compact size to reduce its weight, which is related to comfortable fit and fatigue of patients. Flat type BLDC motor is used for simple and compact structure and various components are used to generate required torque with target working angle and speed. The weight reduction of structure is carried out using optimization method after the initial design process is complete. The optimization is conducted under the load conditions of stair walking. The optimized design is validated via finite element analysis and experiments. As a result, the weight is reduced using topology and shape optimization but maintaining the safety of structure. Also the space efficiency is improved due to its compact size.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.36.2-37
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• 2016

We study the long-term radio variability of 43 radio bright AGNs by exploiting the data base of the University of Michigan Radio Astronomy Observatory (UMRAO) monitoring program. The UMRAO database provides high quality lightcurves spanning 25 - 32 years in time at three observing frequencies, 4.8, 8, and 14.5 GHz. We model the periodograms (temporal power spectra) of the observed lightcurves as simple power-law noise (red noise, spectral power $P(f){\propto}f^{-{\beta}}$ using Monte Carlo simulations, taking into account windowing effects (red-noise leak, aliasing). The power spectra of 39 (out of 43) sources are in good agreement with the models, yielding a range in power spectral index (${\beta}$) from ${\approx}1$ to ${\approx}3$. We find a strong anti-correlation between ${\beta}$ and the fractal dimension of the lightcurves, which provides an independent check of the quality of our modelling of power spectra. We fit a Gaussian function to each flare in a given lightcurve to obtain the flare duration. We discover a correlation between ${\beta}$ and the median duration of the flares. We use the derivative of a lightcurve to obtain a characteristic variability timescale which does not depend on the assumed functional form of the flares, incomplete fitting, and so on. We find that, once the effects of relativistic Doppler boosting on the observed timescales are corrected, the variability timescales of our sources are proportional to the black hole mass to the power of ${\alpha}=1.70{\pm}0.49$. We see an indication for AGNs in different regimes of accretion rate, flat spectrum radio quasars and BL Lac objects, having different scaling relations with ${\alpha}{\approx}1$ and ${\approx}2$, respectively. We find that modelling the periodograms of four of our sources requires the assumption of broken powerlaw spectra. From simulating lightcurves as superpositions of exponential flares we conclude that strong overlap of flares leads to featureless simple power-law periodograms of AGNs at radio wavelengths in most cases (The paper is about to be submitted to ApJ).

• Journal of Mushroom
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• v.3 no.4
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• pp.129-132
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• 2005

A new functional mushroom cultivated variety "Jangsaeng" of Fomitella fraxinea was developed by crossing monokaryons derived from collected strains for contribution to mushroom farmers. The major characteristics of this mushroom were compared to Yeongji 2ho of Ganoderma lucidum because of their morphological similarities. The optimal temperature of mycelial growth and fruitbody sprouting and growth were 30 and 25~30, respectively. The surface color of fruitbody pilus was reddish brown and the fruitbody was flat kidney-shaped like Ganoderma lucidum except that the stipe was absent. Its texture was so tough and rigid that the yield per 1,000 ml bottle might be as high as 136 g. The hot water extract of this medicinal mushroom is fit to drink just like Ganoderma lucidum but its taste is not bitter.

• Journal of Fashion Business
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• v.11 no.3
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• pp.15-34
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• 2007

This study was designed to collect a precise information concerning to the preference and evaluations after usage of pregnant Korean woman for the maternity wear bysurvey and wear tests. Through the survey, 212 respondents were asked to answer what type of maternity wear they prefer and what requirements for maternity wear design are important. According to the results of survey, the mostly preferred maternity wear items were pants and one-piece dress. Korean customers for maternity wear usually pay more for the one-piece dress than other items and they also usually put on medium price pants and low-price blouse. Concerning to the purchase criteria, it may be said that design and movability, fit factors are the buying decision criteria of great weight for Korean pregnant women. Special function most desired was thermal insulation, followed by buffer action, electromagnetic shield and quickly water-absorbent and dry property. Preferred maternity wear design details were flat collar, slightly fitted waist and empire style, gather skirt, rubber band waist. Wear test was performed for two kinds of blouse (BL) and one-piece dress (OP), and threekinds of pants (PT), which have different design details respectively. According to the wear test for ready-to-wear maternity garments, the garment which considers well the characteristics of Korean pregnant women body shape earned much higher score no matter of brands or prices. Generally, high-priced national brands received an excellent evaluation in design aspect, but not satisfied with comfort to move.