• 한국지능시스템학회논문지
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• 제20권6호
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• pp.825-830
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• 2010

일반적으로 인쇄 문서의 위변조를 방지하기위해 복사방지마크와 이차원 바코드가 많이 사용되고 있다. 하지만 이차원 바코드는 복사 방지 마크와 분리 배치되어 있어 사본 구별이 시각적으로 힘들고, 스캐너로만 인식할 수 있다는 단점이 있다. 따라서 본 논문은 이차원 바코드에 워터마크를 삽입해 시각뿐만 아니라 스캐너로 정확하게 구분 할 수 있는 위변조방지기술에 대해 연구했다. 복사 방지마크는 디지털 입출력 장치의 저주파 필터 특성으로 인해 특정 패턴이 소실되거나 변형되는 것을 이용해 패턴으로 만들었다. 원본과 사본을 스캔한 이미지의 히스토그램을 분석을 통해 성능검증을 했다. 그리고 이차원 바코드를 웹캠이나 핸드폰 카메라로 인식한 인증키로 온라인 서버에 접속해 내용을 확인하는 시스템을 제안했다.

• 전기학회논문지
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• 제64권3호
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• pp.458-464
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• 2015

This paper proposes a portable 3-D scanning technique using a laser pointer. 3-D scanning is a process that acquires surface information from an 3-D object. There have been many studies on 3-D scanning. The methods of 3-D scanning are summarized into some methods based on multiple cameras, line lasers, and light pattern recognition. However, those methods has major disadvantages of their high cost and big size for portable appliances such as smartphones and digital cameras. In this paper, a 3-D scanning system using a low-cost and small-sized laser pointer are introduced to solve the problems. To do so, we propose a 3-D localization technique for a laser point. The proposed method consists of two main parts; one is a fast recognition of input images to obtain 2-D information of a point laser and the other is calibration based on the least-squares technique to calculate the 3-D information overall. To verified our method, we carry out experiments. It is proved that the proposed method provides 3-D surface information although the system is constructed by extremely low-cost parts such a chip laser pointer, compared to existing methods. Also, the method can be implemented in small-size; thus, it is enough to use in mobile devices such as smartphones.

• The Journal of the Acoustical Society of Korea
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• 제26권1E호
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• pp.33-38
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• 2007

Compressional wave velocity and shear wave velocity were measured for gassy sediments collected from Jinhae Bay, Korea. To distinguish inhomogeneities of gassy sediments, Computed Tomography (CT) was carried out for gassy sediment using CT Scanner. The cored sediments are composed of homogeneous and soft mud (greater than $8{\Phi}$ in mean grain size) containing clay content more than 50%. In depth interval of gassy sediments, compressional wave velocity is significantly decreased from 1480m/s to 1360m/s, indicating that the gas greatly affects compressional wave velocity due to a gas and/or degassing cracks. Shear wave velocity shows a slight increasing pattern from ${\sim}55\;m/s$ in the upper part of the core to ${\sim}58\;m/s$ at 320 cm depth, and then decreases to ${\sim}54\;m/s$ in the lower part of the core containing a small amount of gas. But shear wave velocity in the gassy sediments is slightly greater than that of non-gassy sediments in the upper part of the core. Thus, the Vp/Vs ratio is decreased (from 30 to 25) in gas charged zone. The Vp/Vs ratio is well correlated with shear wave velocity, but no correlation with compressional wave velocity. This suggests that low concentrations of gas have little affects on shear wave velocity. By CT images, the gas in the sediments is mostly concentrated around inner edge of core liner due to a long duration after sediment collection.

• The Journal of Advanced Prosthodontics
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• 제13권4호
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• pp.191-204
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• 2021

PURPOSE. The purpose of this study is to present a methodology to evaluate the accuracy of intraoral scanners (IOS) used in vivo. MATERIALS AND METHODS. A specific feature-based gauge was designed, manufactured, and measured in a coordinate measuring machine (CMM), obtaining reference distances and angles. Then, 10 scans were taken by an IOS with the gauge in the patient's mouth and from the obtained stereolithography (STL) files, a total of 40 distances and 150 angles were measured and compared with the gauge's reference values. In order to provide a comparison, there were defined distance and angle groups in accordance with the increasing scanning area: from a short span area to a complete-arch scanning extension. Data was analyzed using software for statistical analysis. RESULTS. Deviations in measured distances showed that accuracy worsened as the scanning area increased: trueness varied from 0.018 ± 0.021 mm in a distance equivalent to the space spanning a four-unit bridge to 0.106 ± 0.08 mm in a space equivalent to a complete arch. Precision ranged from 0.015 ± 0.03 mm to 0.077 ± 0.073 mm in the same two areas. When analyzing angles, deviations did not show such a worsening pattern. In addition, deviations in angle measurement values were low and there were no calculated significant differences among angle groups. CONCLUSION. Currently, there is no standardized procedure to assess the accuracy of IOS in vivo, and the results show that the proposed methodology can contribute to this purpose. The deviations measured in the study show a worsening accuracy when increasing the length of the scanning area.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4903-4929
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• 2018

In this study, a fully automatic pose and expression invariant 3D face alignment algorithm is proposed to handle frontal and profile face images which is based on a two pass course to fine alignment strategy. The first pass of the algorithm coarsely aligns the face images to an intrinsic coordinate system (ICS) through a single 3D rotation and the second pass aligns them at fine level using a minimum nose tip-scanner distance (MNSD) approach. For facial recognition, multi-view faces are synthesized to exploit real 3D information and test the efficacy of the proposed system. Due to optimal separating hyper plane (OSH), Support Vector Machine (SVM) is employed in multi-view face verification (FV) task. In addition, a multi stage unified classifier based face identification (FI) algorithm is employed which combines results from seven base classifiers, two parallel face recognition algorithms and an exponential rank combiner, all in a hierarchical manner. The performance figures of the proposed methodology are corroborated by extensive experiments performed on four benchmark datasets: GavabDB, Bosphorus, UMB-DB and FRGC v2.0. Results show mark improvement in alignment accuracy and recognition rates. Moreover, a computational complexity analysis has been carried out for the proposed algorithm which reveals its superiority in terms of computational efficiency as well.

• 생약학회지
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• 제22권3호
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• pp.171-182
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• 1991

Several experiments were carried for the purpose of establishing the basis for the quality evaluation of deer horn. Deer horn originated from China, New Zealand, Soviet and Alaska were used as objectives and some constituents involved in deer horn were assayed and compared with one another. Five kinds of trace elements including Ca and Fe were determined by atomic absorbance spectroscopy. The more the region came down from the top of the deer horn, the more the ratio of Ca to Fe content (Ca/Fe) was increased. The same increasing tendancy was observed in the case of ash content. Gangliosides were isolated from deer horn by alumina column chromatography and identified by TLC using gangliosides Type II obtained from bovine brain as the standard material. The TLC chromatograms were scanned by dual wavelength TLC scanner, then those TLC profiles were compared. Deer horn from China and New Zealand were analogous but those from Soviet and Alaska were each distinguished in their TLC profiles.

• 대한원격탐사학회지
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• 제38권4호
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• pp.343-353
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• 2022

An attempt to derive the surface temperature from the Korea Multi-purpose Satellite (KOMPSAT)-3A mid-wave infrared (MWIR) data acquired over the southern California on Nov. 14, 2015 has been made using the MODerate resolution atmospheric TRANsmission (MODTRAN) radiative transfer model. Since after the successful launch on March 25, 2015, the KOMPSAT-3A spacecraft and its two payload instruments - the high-resolution multispectral optical sensor and the scanner infrared imaging system (SIIS) - continue to operate properly. SIIS uses the MWIR spectral band of 3.3-5.2 ㎛ for data acquisition. As input data for the realistic simulation of the KOMPSAT-3A SIIS imaging conditions in the MODTRAN model, we used the National Centers for Environmental Prediction (NCEP) atmospheric profiles, the KOMPSAT-3Asensor response function, the solar and line-of-sight geometry, and the University of Wisconsin emissivity database. The land cover type of the study area includes water,sand, and agricultural (vegetated) land located in the southern California. Results of surface temperature showed the reasonable geographical pattern over water, sand, and agricultural land. It is however worthwhile to note that the surface temperature pattern does not resemble the top-of-atmosphere (TOA) radiance counterpart. This is because MWIR TOA radiances consist of both shortwave (0.2-5 ㎛) and longwave (5-50 ㎛) components and the surface temperature depends solely upon the surface emitted radiance of longwave components. We found in our case that the shortwave surface reflection primarily causes the difference of geographical pattern between surface temperature and TOA radiance. Validation of the surface temperature for this study is practically difficult to perform due to the lack of ground truth data. We therefore made simple comparisons with two datasets over Salton Sea: National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL) field data and Salton Sea data. The current estimate differs with these datasets by 2.2 K and 1.4 K, respectively, though it seems not possible to quantify factors causing such differences.

• 복식문화연구
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• 제19권6호
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• pp.1347-1358
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• 2011

This study purposed to analyze differences in body measurement between the 2D direct body measuring method and the 3D body scan measuring method and to perform the appearance evaluation and cross-sectional evaluation of the fit of pants to which body measurements obtained by each measuring method were applied. Body measuring was conducted in 10 women in their 20s-30s using 2D direct body measuring and 3D automatic measuring with Hamamatsu body scanner. Among the 10 women, 3 participated in experimental garment wearing. Experimental pants were made using their 2D direct body measurements and 3D automatic measurements, and wearing tests were performed through expert evaluation and cross-sectional evaluation. The results of the experiment were as follows. According to the results of comparative analysis on differences between 2D direct body measurements and 3D scan measurements, 3D automatic measurements were significantly larger in bust circumference, ankle circumference, armscye circumference, shoulder length, scye depth, and arm length. As circumferences measured with the 3D body scanner were somewhat larger than directly measured ones, it is suggested to adjust ease when using existing pattern making methods. We prepared experimental garments by the same pattern making method through applying body measurements obtained with the two measuring methods, and assessed the fit of the garment comparatively through expert evaluation and 3D scan cross-sectional evaluation. According to the results, 2D-pants using 2D direct body measurements was slightly tighter than 3D-pants using 3D measurements in waist circumference, hip circumference, and abdominal circumference. In the results of comparing appearance in terms of the fit of the experimental garment in each subject, significant difference was observed in most of the compared items. This result suggests that 3D automatic body measuring data may show different accuracy according to body shape and therefore it is necessary to examine difference between 2D direct body measurements and 3D automatic measurements according to body shape.

• Tuberculosis and Respiratory Diseases
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• 제42권6호
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• pp.813-822
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• 1995

연구배경: 기도의 과민성과 더불어 반응성의 이상도 기관지천식의 병태생리에 관여한다. 고해상도 전산화 단층촬영술(HRCT)은 기관지조영술보다 비칩습적(non-invasive)이며, 더욱이 기도의 내강을 2차원적으로 측정이 기능하게 되어 훨씬 더 정확하고 신뢰있는 기도의 면적(dimension)을 얻을 수 있다. 방법: 기관지천식에서 메타콜린 기관지유발에 의한 기도 내강의 변화를 관찰하고자 HRCT(5000T CT, Shimadzu Co, Japan)를 이용하여 직접 기도의 반응을 영상화하였다. film scanner(TZ-3X scanner; Truvel Co, Chatsworth CA, USA)를 이용하여 scan 하고 a semiautomated region growing method로 면적을 측정 하였다. 5명의 기관지천식환자에서 $FEV_1$이 20%이상의 감소를 유발하여 기도 내강의 면적이 수축하는 정도를 측정하고, 유발전과 후에 기도의 크기와 폐의 구역에 따른 차이를 알아 보았다. 결과: 1) 메타콜린 흡입후 $FEV_1$이 24.2%에서 45.3%까지 의미있는 수축을 하였으며, 이들에서 기관지수축전후 비교할 수 있는 기도는 상폐야에서는 4개에서 8개, 하폐야에서는 2개에서 6개, 한 환자에서 9개에서 12개까지 면적의 측정이 가능하였다. 2) 메타콜린에 의한 기도의 수축률은 한 환자내에서도 차이가 많았다. 3) 평균 직경 2 mm(면적 $3.14\;mm^2$)이하의 소기도(43개)에서는 48.7%(8.3; SEM) 이였으며, 직경 2mm보다 큰 중심기도(10개)에서는 53.8%(4.4; SEM)으로 소기도에서 더 많은 수축률을 보이는 경향이었으나, 통계적으로 의미있지는 않았다.(p>0.05). 4) 상폐야의 기도(30개)의 수축은 44.3%(5.8; SEM)이었고, 하폐야의 기도(23개)는 56.7%(4.5; SEM)으로 차이가 없었다(p>0.05). 결론: 메타콜린에 의한 기도의 수축은 한 환자 내에서도 차이가 많으며, 폐의 구역이나 기도의 크기에 따른 차이도 없었다. 그 기전에 관하여는 연구가 필요할 것으로 생각된다.

• 대한인간공학회지
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• 제21권2호
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• pp.71-86
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• 2002

This study's purpose is to gain basic data for the factory automation of manufacturing custom-made girdles. For this study , obese women in their 30s and 40s was experimented through direct measuring and by the 3D scanner, by means of which the proportions of the subject's body was measured. Based upon the results of this experiment, individually designed girdles were made. In order to gain the basic data for the factory automation of manufacturing custom-made girdles, the patterns and the clothing pressure and the feeling of wearing such girdles were analyzed. This study can be summarized as follows: The material properties and the designs of existing functional girdles in the market were studied thoroughly, and the subject were required to wear those existing girdles. On the basis of this result, the experimental girdles were designed and produced which could serve well the subject's intension. The experimental girdles were of the basic long-type in order to apply to all sorts of girdles, and they were produced according to the style and pattern of the existing grading system. The second experiment was conducted by applying the subject's body measurements. Due to the elasticity of the material, in girdles the smaller measurements were to be used in this second experiment were: 80% of waist size, 84% of the hip and 85% of the thigh. To determine the length of the girdles, the same measurements were applied. The test results of the feeling of wearing the experimental girdles showed that the second, custom-made experimental girdles were better. According to the test results of the clothing pressure, the second experimental girdles(custom-made girdles) marked the higher pressure than the first on every part of the body, especially on the hips and thighs. Thus, it can be said that the second experimental girdles are better than the first in lifting up the hips. It is expected that the design methods developed in this study can be utilized as basic resources for the factory automation system of manufacturing custom-made girdles.