• 대한원격탐사학회지
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• 제35권1호
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• pp.117-136
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• 2019

In this study, a hybrid-type of day fog detection algorithm (DFDA) was developed based on the optical and textural characteristics of fog top, using the Himawari-8 /Advanced Himawari Imager data. Supplementary data, such as temperatures of numerical weather prediction model and sea surface temperatures of operational sea surface temperature and sea ice analysis, were used for fog detection. And 10 minutes data from visibility meter from the Korea Meteorological Administration were used for a quantitative verification of the fog detection results. Normalized albedo of fog top was utilized to distinguish between fog and other objects such as clouds, land, and oceans. The normalized local standard deviation of the fog surface and temperature difference between fog top and air temperature were also assessed to separate the fog from low cloud. Initial threshold values (ITVs) for the fog detection elements were selected using hat-shaped threshold values through frequency distribution analysis of fog cases.And the ITVs were optimized through the iteration method in terms of maximization of POD and minimization of FAR. The visual inspection and a quantitative verification using a visibility meter showed that the DFDA successfully detected a wide range of fog. The quantitative verification in both training and verification cases, the average POD (FAR) was 0.75 (0.41) and 0.74 (0.46), respectively. However, sophistication of the threshold values of the detection elements, as well as utilization of other channel data are necessary as the fog detection levels vary for different fog cases(POD: 0.65-0.87, FAR: 0.30-0.53).

• 복식
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• 제63권3호
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• pp.1-16
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• 2013

Xiognu people were the first of the Central-Asian nomads to establish a nation in 209 B.C. They always moved around looking for places to breed their animals and fertile grounds, so they wore clothes made of fur and leather and covered their tents with felt from the livestock. This research studies on the literatures, costumes and the achievement of archaeological excavation. Furthermore, to investigate on costumes excavated of Xiongnu, we visited the Mongolian National Museum and the Hermitage Museum. A corn-hat made of felt, a felt hat with ear flaps and a golden crown with a bird on the top were unearthed from a tomb of Xiongnu in Inner mongolia. Women usually wore pigtails, and men wore pigtails or ponytails but they cut their hair short when holding a funeral. Many pigtails discovered in Noyon uul tombs can be considered as their funeral customs. The Xiongnu wore a round or v-neck caftan attached straight sleeves reaching knees in the left folded style, and because they always rode horses, having the length of the caftan not go past their buttocks would have made it more convenient for them. During the period of Western Han, Ho refered to Xiongnu and it became a common name for northern races. They used leather belts and an animal-designed buckle was found. Women commonly rouged their cheeks for a vivid and cute look, and many ornaments were excavated including bracelets, rings and decorations made of gold, silver, copper and jade, among which there were hair ornaments used to identify one's class. A horse pattern with wings and a horn of Golmod T20 was substitution for the Schythian use of deer. Patterns or shape of unearthed articles present in the Xiongnu culture in Noyon uul had a close relationship with Altaic, Greek and Persian cultures. The Xiongnu clothing was made of animals' skin and fur, woolen textiles and felt. It was folded to the left for upper garments, and the pants were adjusted using a belt and shoes were made of leather, which was very suitable for protection against the cold and horse riding. Mobility played a significant role in their clothing.

• 복식문화연구
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• 제19권5호
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• pp.981-992
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• 2011

The objectives of this study were to analyze the design elements of hairstyles, wedding headdresses, and necklines in wedding magazine pictures by using content analysis method and to investigate the differences in image perception according to hairstyle, wedding headdress, and neckline. A quasi-experimental method by questionnaire was used. The experimental design was a $2{\times}5{\times}4$(hairstyles${\times}$wedding headdresses${\times}$necklines) factorial design by 3 independent variables. The subjects consisted of 378 female college students. The results are as follow. First, the most popular among hairstyles, headdresses, and neckline forms were the updo hairstyle, dark brown hair color, the crown headdress, white flowers, and the horizontal bared top. Second, the elements determined to be most elegant and attractive were the medium-up hairstyle and the crown with a veil. However the wedding hat was perceived to be high in individuality and tenderness, while the flower and the wedding hat were perceived to be very pretty. The halter neckline was perceived to be higher in individuality and attractiveness than the other neckline types. Third, the medium-up hairstyle when wearing a crown with veil was perceived to be the most elegant. Placing a flower in the long-wave hairstyle was evaluated as looking most pretty. Fourth, the medium-up hairstyle was higher in preference than the long-wave style. Among wedding headdresses, there was greatest preference for a crown.

• Steel and Composite Structures
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• 제1권1호
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• pp.17-32
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• 2001

The Rosette-joining system is a completely new press-joining method for cold-formed steel structures. One Rosette-joint has a shear capacity equal to that of approximately four screws or rivets. The Rosette thin-walled steel truss system presents a new fully integrated prefabricated alternative to light-weight roof truss structures. The trusses are built up on special industrial production lines from modified top hat sections used as top and bottom chords and channel sections used as webs which are joined together with the Rosette press-joining technique to form a completed structure easy to transport and install. A single web section is used when sufficient but can be strengthened by double-nesting two separate sections or by using two lateral profiles where greater compressive axial forces are met. An individual joint in the truss can be strengthened by introducing a hollow bolt into the joint hole. The bolt gives the connection capacity a boost of approximately 20%. A series of laboratory tests have been carried out in order to verify the Rosette truss system in practice. In addition to compression tests on individual sections of different lengths, tests have also been done on small structural assemblies and on actual full-scale trusses of a span of 10 metres. Design calculations have been performed on selected roof truss geometries based on the test results, FE-analysis and on the Eurocode 3 and U.S.(AISI) design codes.

• 정보처리학회논문지A
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• 제9A권4호
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• pp.485-490
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• 2002

디지털 TV, 인터넷 셋탑박스, 인터넷 전화기 등과 같은 정보가전 제품이 속속 등장하면서 이들 제품의 기능을 제어하는데 필수적인 실시간 운영체제 시장이 크게 성장하고 있다. 한국전자통신연구원에서는 소형의 휴대 정보 단말에서부터 디지털 셋탑박스 및 홈 서버까지 다양한 종류의 정보가전 기기에 공통으로 사용될 수 있는 확장 가능한 표준 실시간 운영체제 Qplus-P를 개발하였다. 본 논문에서는 정보가전용 실시간 운영체제 Qplus-P에 탑재되는 C표준 라이브러리의 설계 및 구현에 대해 기술한다. Qplus-PC표준 라이브러리는 레드햇에서 실시간 운영체제 국제 표준으로 제안된 EL/LX 응용 프로그램 인터페이스 단계에 따라 설계되었다. 그리고 Qplus-P 응용 프로그램 수행에 필요한 Tiny-X, 카페 등을 지원하기 위해 추가적으로 필요한 함수들도 구현되었다. 구현된 C표준 라이브러리는 EL/IX 응용프로그램 인터페이스 단계를 적용하지 않은 C표준 라이브러리보다 라이브러리 크기를 30% 정도 줄일 수 있었다.

• 한국생산제조학회지
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• 제21권4호
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• pp.644-650
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• 2012

This paper show the 2kW fiber laser cutting properties of SS400. The study was comparison of traditional 4kW $CO_2$ Laser cutting and 2kW Fiber laser cutting characteristics for the application of Industrial 2D Laser Cutting Machine. The laser used in this investigation was an IPG YLU-2000 multi-mode Ytterbium Fiber machine with a maximum power of 2000W and a wave length of 1070 nm. The laser was used in its Continuous Wave (CW) mode with an approximately top hat beam intensity distribution. Fiber laser high quality cuts at a large range of speeds (ranging from 2000 to 3800 mm/min) which has been obtained for the 2.3mm Sheet of SS400. 2kW power Fiber laser cut was able to max. 20mm sheets of SS400 (speed range from 650 to 850 mm/min). Fiber laser cutting used in conventional hole nozzle could cut 12mm SS400 but used in special dual cutting nozzle could cut 20mm SS400.

• Journal of Welding and Joining
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• 제33권4호
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• pp.7-16
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• 2015

New lasers such as high power, high brightness and short wavelength laser are using diverse industry. Also new technologies are developing actively to solve various issues such as spattering, process monitoring, deep penetration and key-hole stability. ICALEO is the international congress where recent technology for laser material processing and laser system are present. At 2014, it was held at San Diego in USA and more than 260 papers were presented from 28 country. The effect of the laser beam shape such as Gaussian like and top-hat was investigated on acoustic emission signal and pore formation in welding. Inline penetration depth was measured with ICI(Inline Coherent Imaging) technique and the data was verified with real time X-ray image on laser welding. The laser welding performance at low pressure environment was evaluated for the thick plate alloy steel. UV laser was used to weld various metals such as Cu, Aluminum, steel and stainless steel. The effect of the wavelength of the laser on the formation of the wave at the wall of the key-hole front and the absorptivity was investigated.

• Journal of Information Processing Systems
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• 제9권1호
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• pp.103-116
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• 2013

Prostate cancer is one of the most frequent cancers in men and is a major cause of mortality in the most of countries. In many diagnostic and treatment procedures for prostate disease accurate detection of prostate boundaries in transrectal ultrasound(TRUS) images is required. This is a challenging and difficult task due to weak prostate boundaries, speckle noise and the short range of gray levels. In this paper a method for automatic prostate segmentation in TRUS images using Gabor feature extraction and snake-like contour is presented. This method involves preprocessing, extracting Gabor feature, training, and prostate segmentation. The speckle reduction for preprocessing step has been achieved by using stick filter and top-hat transform has been implemented for smoothing the contour. A Gabor filter bank for extraction of rotation-invariant texture features has been implemented. A support vector machine(SVM) for training step has been used to get each feature of prostate and nonprostate. Finally, the boundary of prostate is extracted by the snake-like contour algorithm. A number of experiments are conducted to validate this method and results showed that this new algorithm extracted the prostate boundary with less than 10.2% of the accuracy which is relative to boundary provided manually by experts.

• 대한기계학회논문집B
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• 제27권7호
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• pp.853-858
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• 2003

The suitable estimation of the filter width in the dynamic eddy viscosity model were investigated in high Reynolds number channel flow. In this study, the improvement on matters by optimizing the test filter shape was attempted through the numerical experiment. The way that select optimum test filter width is recommended. Some test filters, one is based on a discrete representation of the top-hat filter and another are based on a high-order filtering operation, are evaluated in simulations of the turbulent channel flow at Reynolds number 1020, based on friction velocity and channel half width. It appears that the estimation of test filter width practically can decrease the dissipative nature of dynamic eddy viscosity model with explicit test filter. It shows that the value of the filter width ratio used in the dynamic procedure must match the properties of the test filter actually used in the calculation.

• Journal of Computing Science and Engineering
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• 제8권2호
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• pp.119-128
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• 2014

The appearance of retinal blood vessels is an important diagnostic indicator of serious disease, such as hypertension, diabetes, cardiovascular disease, and stroke. Automatic segmentation of the retinal vasculature is a primary step towards automatic assessment of the retinal blood vessel features. This paper presents an automated method for the enhancement and segmentation of blood vessels in fundus images. To decrease the influence of the optic disk, and emphasize the vessels for each retinal image, a multidirectional morphological top-hat transform with rotating structuring elements is first applied to the background homogenized retinal image. Then, an improved multiscale line detector is presented to produce a vessel response image, and yield the retinal blood vessel tree for each retinal image. Since different line detectors at varying scales have different line responses in the multiscale detector, the line detectors with longer length produce more vessel responses than the ones with shorter length; the improved multiscale detector combines all the responses at different scales by setting different weights for each scale. The methodology is evaluated on two publicly available databases, DRIVE and STARE. Experimental results demonstrate an excellent performance that approximates the average accuracy of a human observer. Moreover, the method is simple, fast, and robust to noise, so it is suitable for being integrated into a computer-assisted diagnostic system for ophthalmic disorders.