• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.621-628
• /
• 2021

This paper proposes a method to calibrate a thermal camera with three different perspectives. In particular, the intrinsic parameters of the camera and re-projection errors were provided to quantify the accuracy of the calibration result. Three lenses of the camera capture the same image, but they are not overlapped, and the image resolution is worse than the one captured by the RGB camera. In computer vision, camera calibration is one of the most important and fundamental tasks to calculate the distance between camera (s) and a target object or the three-dimensional (3D) coordinates of a point in a 3D object. Once calibration is complete, the intrinsic and the extrinsic parameters of the camera(s) are provided. The intrinsic parameters are composed of the focal length, skewness factor, and principal points, and the extrinsic parameters are composed of the relative rotation and translation of the camera(s). This study estimated the intrinsic parameters of thermal cameras that have three lenses of different perspectives. In particular, image enhancement based on a deep learning algorithm was carried out to improve the quality of the calibration results. Experimental results are provided to substantiate the proposed method.

• Journal of Conservation Science
• /
• v.37 no.6
• /
• pp.670-678
• /
• 2021

Anseong Cheonryongsa, a temple located in Anseong Seoun Mountain, is a part of the second Jogye Order of Korean Buddhism, under the Yongju Temple, and enshrines a gilt-bronze seated Avalokitesvara Bodhisattva. In this study, X-ray fluorescence (XRF) analysis revealed that this statue is composed of Cu-27.2 wt%, Sn-12.6 wt% and Pb-48 wt%. A gamma (γ) ray (Ir-192) image confirmed damage on the backside of the statue, which was later repaired with wood. The XRF analysis and visual observation determined the boundary between the metal and wood in the statue. In addition, results of standard X-ray peak intensity of gold foil and correlation with thickness helped to derive an equation for calculating the thickness of the Avalokitesvara Bodhisattva's gold foil. It was determined that the gilded chest (21 ㎛) and face (20.7 ㎛) of the statue were the thickest sections, the wooden substratum (11.9 ㎛) was the next-most thick, and the bronze (7.4 ㎛) was the thinnest layer.

• Tunnel and Underground Space
• /
• v.32 no.6
• /
• pp.373-385
• /
• 2022

The drum cutter, which is used in the form of an attachment of a excavator, is very useful in that it can be used in connection with a excavator that can perform various tasks in the field. This study estimated the load and torque acting on the drum cutter attachment by measuring the hydraulic pressure and strain that appear during excavation on the exposed rock slope using the drum cutter installed in the excavator. Working conditions such as the operation angle between the boom and arm of the excavator were divided into eight working modes. And as a result of analyzing the variations in hydraulic pressure and action force according to the working mode, it was confirmed that the hydraulic pressure and flow rate can be driven without any problems within the range considered in the manufacturing specifications of the drum cutter. The average load and torque acting on the drum cutter were within the range of the manufacturing specifications, but the maximum load was up to four times the specification. Because sumping was not properly performed due to the high ground strength and the ground included discontinuous surfaces in some locations, no trend of load and torque was found depending on the angle between the boom and arm of the excavator. However, it is believed that this result can be used to determine the range of loads and torques that appear on the drum cutter when excavating a high-intensity rock.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.1
• /
• pp.539-544
• /
• 2023

The subject of this study is the Maae Buddha statue in granodiorite of the Mesozoic Cretaceous period, which is concerned about stability as a standing stone cultural property located in ◯◯-dong, Gyeongsangbuk-do. For stability analysis, three-dimensional face mapping, geological properties of joints, three-dimensional scanning, ultrasonic velocity, polarization microscopy, electron microscopy analysis and XRD analysis were performed. In addition, the safety factor of the Maaebul was calculated by analyzing the damage status investigation, stereographic projection analysis, rock classification, and limit equilibrium analysis. The types and scales of damage and possible collapse by section depend on the degree of weathering of the rock and the orientation and characteristics of the joints, but wedge-failure and toppling-failure are expected to be small-scale. The safety factor of Maaebul in dry and wet conditions is less than 1.2, so stability is concerned. The types of damage were mainly observed, such as exfoliation, cracking, granular decomposition, and vegetation growth. The Maaebul rock is granodiorite, and the surface discoloration materials are K, Fe, and Mg. The 4 sets of joints are developed, J1 is tensile joint and the others are shear joint. The uniaxial compressive strength estimated by ultrasonic exploration is 514kgf/cm2, which corresponds to most soft rocks and some weathered rocks. Rock classification(RMR) is estimated to be grade 5, very poor rock mass. These technique along with the existing methods of safety diagnosis of cultural properties are expected to be a reasonable tool for objective interpretation and stability review of stone cultural properties.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.246-246
• /
• 2020

최근 우리나라에서 농업용수의 다원적 기능에 대한 공감대가 형성되고 작물생육에 필요한 관개용수로만 인식되던 농업용수의 개념이 농촌생활환경개선을 포함하는 다양한 지역용수로의 포괄적 개념으로 전환되고 있다. 농업용수는 식량생산 이외의 효용을 위한 다원적 기능을 가지며 농촌지역의 각종 생산활동과 생활조건의 유지개선을 위한 농업용수의 다원적 기능에 관한 관심이 증가하는 추세이다. 농업용수에서 발생하는 회귀수는 유역의 용수공급계획, 하천 유황의 예측, 관개용수 사용량 결정, 하천 건전화 방지, 수생생태계 보호 및 생물 다양성 확보 등 농업용수의 효율적 사용 및 환경생태유지를 위해 매우 중요한 역할을 하고 있다. 농업용수 회귀수량은 농업용수 중 하천으로 회귀하는 수량을 의미한다. 본류의 생태 유량 확보에 농업용수 회귀 수량이 기여하고 있으며 본류 하천의 환경 보전 기능을 하고 있다. 또한, 수생태계 보호 및 생물 다양성 확보 등 환경 생태 유지에 매우 중요한 역할을 하고 있다. 하지만 농업용수 회귀수량이 하천 수생태에 미치는 영향 분석 연구는 미흡한 실정이다. 따라서 본 연구의 목적은 대사 저수지 유역을 대상으로 농업용수 회귀 수량이 하류 하천 수생태에 미치는 영향을 정량적으로 평가하고자 한다. 본 연구에서는 회귀 수량은 관개용수량, 배수량, 침투량, 담수심 등 물수지 항목을 논물수지 모형에 적용하여 산정하였으며, 하류 하천의 생태유량 산정을 위해 대사저수지 하류에 위치한 생물측정망 자료를 통해 대표 어종을 선정하였다. PHABSIM 모형을 이용해 모의 대상 지역 특성 자료 및 인근 소하천 생물측정망 자료를 바탕으로 HSI 기반 대표 어종 서식처 환경에서 최적 생태유량을 산정하였다. 이를 통해 추정된 농업용수 회귀 수량에 따른 필요 유량이 어류 서식환경에 미치는 영향을 평가하였다. 본 연구 결과 대사저수지 하류 하천에서 농업용수 회귀수량이 차지하고 있는 기여도 큰 것으로 분석되었으며, 최적 생태유량과 비교한 결과 농업용수 회귀수량이 수생태(어류)에 미치는 영향이 큰 것으로 나타났다. 따라서 농업용수 회귀수량은 하류 하천의 하천유지수량뿐만 아니라 하천 환경생태유지에도 매우 중요한 역할을 하고 있음을 알 수 있다.

• Journal of Korean Society of Transportation
• /
• v.35 no.4
• /
• pp.261-277
• /
• 2017

This study defines influencing sections as the part of the road section where passing vehicles are traveling with the lower speed compared to speed limit due to speed humps. The influencing section was divided into 3 parts; influencing section before the speed hump, interval section, and influencing section after the speed hump. This analysis focused on the changes of each part depending on installation types, vehicle types, and daytime or nighttime. For the interval section, especially, the ratio of distance traveled with lower speed than speed limit to interval section is defined as effective influencing section ratio to be analyzed. Vehicle speed profiles were collected with a speed gun to extract influencing section lengths. The survival analysis was applied and estimated survival functions are compared with each other by several statistical tests. As a consequence, the average length of influencing section on the 50m sequential speed humps was 75.3% longer during the deceleration than that of isolated speed hump, and 18.9% during the acceleration. The effective influencing section ratio for the 30m and 50m sequential speed humps had a small difference of 81.0% and 76.0% while the absolute values of the section that passing speed were less than the speed limit were longer on 50m sequential speed humps, each being 24.3m and 38.0m. Using the log rank test, it was evident that sequential speed humps were more effective to increase the length of influencing sections compared to the isolated speed hump. Vehicle type was the strong factor for influencing section length on the isolated speed hump, but daytime or nighttime was not the effective one. This research result can be used for improving the efficiency selecting the installation point of speed humps for road safety and estimating the standard of the distance between sequential speed humps.

• Korean Journal of Food Science and Technology
• /
• v.27 no.5
• /
• pp.716-723
• /
• 1995

The fucoidan purified from Korean brown seaweed, Ecklonia stolonifera was characterized on molecular structure and blood anticoagulant activities. Extraction was conducted at $100^{\circ}C$ with water and repeated twice. The crude fucodian was 151.1g out of 20.0 kg of Ecklonia stolonifera. The Fucoidan-1, which was purified from crude fucoidan using calcium chloride and cetyl pyridium chloride (CPC), was 35.2% against crude fucoidan. Fucoidan-5 was obtained approximately 28.1% from Fucoidan-1 through DEAE-Toyopearl 650 M ion-exchange column chromatography and showed one band by cellulose acetate electrophoresis. The molecular weight of Fucoidan-5 was estimated to be about 21,000∼23,000 dalton by Sephacryl S-300 gel filtration chromatography. Fucoidan-5 consists of 35.7% of fucose and 4.3% of galactose and the molar ratio of fucose and sulfate was about one to one. IR spectrum of Fucoidan-5 showed absorption at $1240\;cm^{-1}\;and\;850\;cm^{-1}$ and specific rotation value, $[\alpha]$, was $[\alpha]$. These results suggests that the sulfate maybe bind at $C_{4}$ carbon on ${\alpha}-L-fucose$. Gas chromatograph of methyl alditol acetate revealed that Fucoidan-5 is a fucose containing sulfated polysaccharide with $({\alpha}l-2)\;or\;({\alpha}l-2)$ glycosidic linkage. Anti-thrombin activity of the Fucoidan-5 was estimated as 1.4 time stronger than heparin. From above results, the purification methods using CPC and ion exchange chromatography is effective tools for obtaining highly purified fucoidan from Gompi, Ecklonia stolonifera.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.31 no.4 s.54
• /
• pp.289-293
• /
• 2005

Nowadays there are many sun protection cosmetics including organic or inorganic UV filter as an active ingredient. Chemically stable inorganic sunsEreen agents, usually metal oxides, we widely employed in high SPF products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as pigments for a long period of cosmetic history. With the development of micronization techniques, it becomes possible to incorporate titanium dioxide in sunscreen formulations without whitening effect and it becomes an important research topic. However, there are very few works related to quantitations of titanium dioxide in sunscreen products. In this research, we analyzed amounts of titanium dioxide in sunscreen cosmetics by adapting redof titration, reduction of Ti(IV) to Ti(III) and reoxidation to Ti(IV). After calcification of other organic ingredients of cosmetics, titanium dioxide is dissolved by hot sulfuric acid. The dissolved Ti(IV) is reduced to the Ti(III) by adding aluminum metals. The reduced Ti(III) is titrated against a standard oxidizing agent, Fe(III) (ammonium iron(III) sulfate), with potassium thiocyanate as an indicator In order to test accuracy and applicability of the proposed method, we analyzed the amounts of titanium dioxide in four types of sunscreen cosmetics, such as cream, make-up base, foundation and powder, after adding known amounts of titanium dioxide $(1{\sim}25w/w%)$. The percent recoveries of the titanium dioxide in four types of formulations were in the range between 96 and 105%. We also analyzed 7 commercial cosmetic products labeled titanium dioxide as an ingredient and compared the results with those of obtained from ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry), one of the most powerful atomic analysis techniques. The results showed that the titrated amounts were well coincided with the analyzed amounts of titanium dioxide by ICP-AES. Although instrumental analytical methods, ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) and ICP-AES, are the best for the analysis of titanium, it is hard to adopt because of their high prices for small cosmetic companies. It was found that the volumetric method presented here gat e quantitative and reliable results with routine lab-wares and chemicals.

• Korean Journal of Heritage: History & Science
• /
• v.53 no.4
• /
• pp.118-135
• /
• 2020

It is not uncommon in Korea to see the structure and function of a garden remain intact as well as its form. Yi Cheon-bo's Historic House (Gyeonggi-do Cultural Heritage Item No. 55), located in Sang-myeon, Gapyeong-gun, Gyeonggi-do, is considered an example of very valuable garden heritage, although its family history, location, and remaining buildings and natural cultural assets are not fully intact. Along with Yi Cheon-bo's Historic House, this study attempted to explore the possibility of restoration of the forest houses and gardens by highlighting the high value of Yi Cheon-bo's Historic House through research into the typical layout of private households in northern Gyeonggi Province and Gapyeong County, comparative review of aerial photographs from 1954, and interviews with those involved. The results of the study are as follows: In this study, the presence of Banggye-dongmun and Bansukam in the Banggyecheon area, where the location of the garden was well-preserved, was examined across the landscape of the outer garden, while the location of Yi Cheon-bo's Historic House, the appearance of feng shui, and the viewing axis were considered. Also, the appearance of the lost main house was inferred from the arrangement and shape of the Sarangchae and Haengrangchae that remain in the original garden, and the asymmetry of the Sarangchae Numaru and the hapgak shape on the side of the roof. In addition, the three tablets (Pyeonaeks) of Sanggodang (尙古堂), Bangyejeongsa (磻溪精舍), and Okgyeongsanbang (玉聲山房) were used to infer the landscape, use, and symbolism of the men's quarters. Also, a survey was conducted on the trees that existed or existed in the high prices. Incidentally, it was confirmed that information on boards and cultural properties of Yeonha-ri juniper (Gyeonggi-do Monument No. 61) was recorded to a much lesser extent than the actual required standard, and the juniper trees remaining in the front of Haengrangchae should also be re-evaluated after speculation. On the other hand, as a result of estimating the original shape as a way of pursuing completeness of the garden through restoration of the lost women's quarters and shrine, it is estimated that the main house was placed in the form of a '口' or a 'be warped 口' on the right (north) side of the men's quarters. By synthesizing these results, a restoration alternative for Yi Cheon-bo's Historic House was suggested.

• Geophysics and Geophysical Exploration
• /
• v.26 no.1
• /
• pp.18-30
• /
• 2023

Submarine mud volcanos are topographic features that resemble volcanoes, and are formed due to eruptions of fluidized or gasified sediment material. They have gained attention as a source of subsurface heat, sediment, or hydrocarbons supplied to the surface. In the continental slope of the Canadian Beaufort Sea, mud volcano exists at various water depths. The MV420, is an active mud volcano erupting at a water depth of 420 meters, and it has been the subject of extensive study. The Korea Polar Research Institute(KOPRI) collected high-resolution seismic data and heat flow data around the caldera of the mud volcano. By analyzing the multi-channel seismic data, we confirmed the reverse-polarity reflector assumed by a gas hydrate-related bottom simulating reflector(BSR). To further elucidate the relationship between the BSR and gas hydrates, as well as the thermal structure of the mud volcano, a numerical geothermal model was developed based on the steady-state heat equation. Using this model, we estimated the base of the gas hydrate stability zone and found that the BSR depth estimated by multi-channel seismic data and the bottom of the gas hydrate stability zone were in good agreement., This suggests the presence of gas hydrates, and it was determined that the depth of the gas hydrate was likely up to 50 m, depending on the distance from the mud conduit. Thus, this depth estimate slightly differs from previous studies.