• Title/Summary/Keyword: gravity center

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Construction of 3D Digital Maps Using 3D Symbols (3차원 심볼을 활용한 3차원 수치지도 제작에 관한 연구)

  • Park, Seung-Yong;Lee, Jae-Bin;Yu, Ki-Yun;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.5
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    • pp.417-424
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    • 2006
  • Despite of many researches related to create 3D digital maps, it is still time-consuming and costly because a large part of 3D digital mapping is conducted manually. To circumvent this limitation, we proposed methodologies to create 3D digital maps with 3D symbols automatically. For this purpose, firstly, the 3D symbol library to represent 3D objects as 3D symbols was constructed. In this library, we stored the attribute and geometry information of 3D objects which define types and shapes of symbols respectively. These information were used to match 3D objects with 3D symbols and extracted from 2D digital maps and LiDAR(Light Detection and Ranging) data. Then, to locate 3D symbols into a base map automatically, we used predefined parameters such as the size, the height, the rotation angle and the center of gravity of 3D objects which are extracted from LiDAR data. Finally, the 3D digital map in urban area was constructed and the results were tested. Through this research, we can identify that the developed algorithms can be used as effective techniques for 3D digital mapping.

3-D P-wave Velocity Structure in South Korea using Seismic Tomography (지진 토모그래피 방법을 이용한 남한에서의 3차원 P파 속도구조)

  • 박재우;민경덕;전정수;제일영
    • Economic and Environmental Geology
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    • v.35 no.5
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    • pp.445-454
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    • 2002
  • 3-D P-wave velocity model in the southern Korean Peninsula is investigated by using the earthquake tomography method. This velocity model would be used to locate the exact hypocenter position, and also useful for our understanding of the crustal structure. The simultaneous inversion is used to get the minimum 1-D model and hypo-center relocation, which are used as an initial 3-D velocity model. The velocities in the minimum 1-D model are 6.04 km/s, 6.45 km/s, and 7.78 km/s between the depth of 0-19 km, 19-32 km, and 32-55 km respectively. In the 3-D P-wave velocity model, Layer 1 (0~3 km) has high velocities in Kyongsang basin, Yonglam massif, and Okchon folded belt, and low velocities in Kyonggi massif. In layer 2 (3~19 km) high velocities are predominent around Kyonsang basin and Yongnam massif except Yonil basin, but low velocities exist around Kyonggi massif and Okchon folded belt. In Laye. 3 (19~32 km) high velocities prevail throughout the southern part of Korean Peninsula, but low velocity does throughout the middle except SNU, YIN station in Konggi massif. In Layer 4 (32 km), the maximum velocity is showed in the middle and southwestern part, while the minimum velocity in the southeastern and coastal area. The depth of the velocity boundary corresponds to the crustal structure of the southern Korean Peninsula which is calculated by gravity data.

Effects of Egg White Manufacturing Conditions on the Physicochemical and Sensory Properties of Angel Food Cakes (난백분말 제조 조건에 따른 엔젤 푸드 케이크의 특성 변화)

  • Yang, Hae-Young;Kim, Min-Young;Kim, Jeong-Yeon;Shim, Jae-Yong;Imm, Jee-Young;Park, Ki-Hwan
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.167-172
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    • 2009
  • The principal objective of this study was to determine the optimum manufacturing conditions of egg white with high foaming property for the production of angel food cakes. The egg whites were desugarized and powdered at predetermined pHs and drying temperatures. The physicochemical properties of the produced cakes were measured and sensory evaluations were conducted on a 9-point scale. The volume and textural properties of cakes produced from spray-dried egg whites did not differ from those of the cakes prepared from the control egg whites. The pH of batter and the specific gravity of foam and batter with egg white powder at pH 6.74/66.5$^{\circ}C$ did not differ from those of the control, whereas the one prepared with commercial powder lost the characteristics of cake to a significant degree. The overall acceptance scores of egg white powder of pH 6.74/66.5$^{\circ}C$ and commercial powder were 6.25 and 2.33 as compared to the control (6.42). These results indicate that the egg white powder that was desugarized, pH-adjusted to 6.74, and dried at 66.5$^{\circ}C$ might be utilized to prepare angel food cakes with the desirable physicochemical and sensory attributes.

The Realization of Intensity-modulated Radiation Therapy Using the Liquid Shielding Material (액체 차폐물을 이용한 강도변조방사선치료의 구현)

  • 오영기;김진기;신교철;김기환;윤상모;김재철;박인규
    • Progress in Medical Physics
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    • v.12 no.2
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    • pp.155-160
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    • 2001
  • We developed a new method that the radiation field shape and intensity could be controlled automatically with a insertion of the liquid shielding material box having a rotatable model imitated the 3-dimensional target volume within. The molded box filled with the mercury was mounted to the tray. A acrylic model imitated the 3-dimensional target volume was fixed into the center of the interior of the box. Although the gentry rotate, the acrylic model can be returned to the original direction of the target due to the action of the gravity. The film measurements at the gantry rotation angle 0$^{\circ}$, 45$^{\circ}$, and 90$^{\circ}$, respectively were shown that the radiation intensities were modulated properly and the field shapes were conformed to the target. We verified the dose distribution for our method with a cylindrical acrylic phantom inserted a film within. In the case of the 8-field irradiation, the 80% isodose line was enclosed the target shape properly. This results show the realization of a new intensity-modulated radiation therapy(IMRT).

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Distribution of Pyroclastic Density Currents Determined by Numerical Model at Mt. Baekdu Volcano (백두산 화산에서 수치모형 분석에 의한 화쇄류의 영향 범위)

  • Yun, Sung-Hyo;Chang, Cheolwoo;Kim, Sunkyeong
    • The Journal of the Petrological Society of Korea
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    • v.23 no.4
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    • pp.351-366
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    • 2014
  • We assumed the situation where an eruption column had been formed by the explosive Plinian eruption from Mt. Baekdu and that the collapse of eruption column had caused pyroclastic density currents to occur. Based on this assumption, we simulated by using a Titan2D model. To find out about the range of the impacts of pyroclastic density currents by volcanic eruption scenarios, we studied the distance for the range of the impacts by VEIs. To compare the results by each volcanic eruption scenario, we set the location of the vent on the 8-direction flank of the outer rim and on the center of the caldera, the internal friction angle of the pyroclastic density currents as $35^{\circ}$, the bed friction angle as $16^{\circ}$. We set the pile height of column collapse and the vent diameter with various VEIs. We properly assumed the height of the column collapse, the diameter of the vent, the initial rates of the column collapse and the simulation period, based on the VEIs, gravity and the volume of the collapsed volcanic ash. According to the comparative analysis of the simulation results based on the increase of the eruption, the higher VEI by the increase of eruption products, the farther the pyroclastic density currents disperse. To the northwest from the vent on the northeast slope of the outer rim of the caldera, the impact range was 3.3 km, 4.6 km, 13.2 km, 24.0 km, 50.2 km, 83.4 km or more from VEI=2 to VEI=7, respectively. Once the database has been fully constructed, it can be used as a very important material in terms of disaster prevention and emergency management, which aim to minimize human and material damages in the vicinity of Mt. Baekdu when its eruption causes the pyroclastic density currents to occur.

Deterioration Analysis and Source Area on Rock Properties of the Seokgatap Pagoda in the Bulguksa Temple, Korea (불국사 석가탑의 풍화훼손도 분석 및 기원암의 산지추정)

  • Lee, Myeong-Seong;Lee, Chan-Hee;Suh, Man-Cheol;Choi, Seok-Won
    • 한국문화재보존과학회:학술대회논문집
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    • 2004.10a
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    • pp.15-24
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    • 2004
  • The Seokgatap pagoda composed of mainly alkali granite and other minor pink-feldspar granite, fine-grained granite, granodiorite, diorite, gabbro, and tuff. Despite the small loss and damage derived from joints, its peel-off and exfoliation are serious enough to cause the heavy deterioration on the stone surface. The chemical and petrological weathering has partly replaced the original rock-forming minerals with clay minerals and iron oxyhydroxides. Based on the petrogenesis, rock materials of the pagoda is very similar to rocks of Dabotap pagoda and the Namsan granite in the Gyeongju. The central fart of the pagoda has sunken highly, which caused all the corners to split and the structural transformation to become worse. The reverse V-shaped gaps between the materials have broken stones filled in a coarse way. The iron plates inserted between the upper flat stone laid on other stones and tile pagoda body in the north and east side has been exposed in the air and corroded, discoloring of the adjacent stones. The overall diagnosis of the Seokgatap pagoda is the deteriorated functions of the stone materials, which calls for a long-term monitoring and plans to reinforce the stone surfaces. But the main body including the pagoda roof stone needs washing on a regular basis, and the many different cracks should be fixed with glue by using the fillers or hardeners designed for stone cultural properties after removing the cement mortar. In case of the replacement of the stone materials with new stones, it's necessary to examine the pagoda for the center of gravity and support intensity of the materials. The structural stability of the pagoda can be attained by taking a reinforce measure in geotechnical engineering and making a drainage. The ground humidity, which has aggravated weathering and structural instability, should be resolved by setting up a humidity reduction facility. The contamination of lichens and bryophyte around the pagoda and on the surface is serious. Thus biochemical treatments should be given too in order to prevent further biological damages and remove the vegetation growing on the discontinuous planes.

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Development of an Integrated DataBase System of Marine Geological and Geophysical Data Around the Korean Peninsula (한반도 해역 해양지질 및 지구물리 자료 통합 DB시스템 개발)

  • KIM, Sung-Dae;BAEK, Sang-Ho;CHOI, Sang-Hwa;PARK, Hyuk-Min
    • Journal of the Korean Association of Geographic Information Studies
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    • v.19 no.2
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    • pp.47-62
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    • 2016
  • An integrated database(DB) system was developed to manage the marine geological data and geophysical data acquired from around the Korean peninsula from 2009 to 2013. Geological data such as size analysis data, columnar section images, X-ray images, heavy metal data, and organic carbon data of sediment samples, were collected in the form of text files, excel files, PDF files and image files. Geophysical data such as seismic data, magnetic data, and gravity data were gathered in the form of SEG-Y binary files, image files and text files. We collected scientific data from research projects funded by the Ministry of Oceans and Fisheries, data produced by domestic marine organizations, and public data provided by foreign organizations. All the collected data were validated manually and stored in the archive DB according to data processing procedures. A geographic information system was developed to manage the spatial information and provide data effectively using the map interface. Geographic information system(GIS) software was used to import the position data from text files, manipulate spatial data, and produce shape files. A GIS DB was set up using the Oracle database system and ArcGIS spatial data engine. A client/server GIS application was developed to support data search, data provision, and visualization of scientific data. It provided complex search functions and on-the-fly visualization using ChartFX and specially developed programs. The system is currently being maintained and newly collected data is added to the DB system every year.

The Failure Model of RC Flat Plates Considering Interrelation between Punching Shear and Unbalanced Moment (불균형모멘트와 펀칭전단의 상관관계를 고려한 철근콘크리트 무량판 슬래브의 파괴모델)

  • Choi, Jung-Wook;Song, Jin-Kyu;Song, Ho-Beom
    • Journal of the Korea Concrete Institute
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    • v.20 no.4
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    • pp.523-530
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    • 2008
  • In structural design provision, maximum punching shear stress of slabs is prescribed as combined stress in direct shear occurred by gravity load and eccentric shear occurred by unbalanced moment. This means that the effect of unbalanced moment is considered to decide the punching shear stress. However, from the resistance capacity standpoint, the effect of unbalanced moment strength is not considered for deciding punching shear strength. In this paper, a model considering interrelation between unbalanced moment and punching shear was proposed. In the model, the relation between load effect and resistance capacity in unbalanced moment and punching shear was two-dimensionally expressed. Using the interrelation model, a method how unbalanced moment strength should be considered to decide the punching shear strength was proposed. Additionally, effective width enlargement factors for deciding the unbalanced moment strength of flat plates with shear reinforcements were proposed. The interrelation model proposed in this paper is very effective for the prediction of the behavior of slab-column connection because not only punching shear and unbalanced moment strengths but also failure modes of flat plates can be accurately predicted.

Development and Commercialization of Artificial Reefs from Waste Mulch Plastic Films (농업용(農業用) 멀칭 폐(廢)비닐로부터 인공어초(人工魚礁) 개발(開發) 및 상용화(商用化))

  • Kim, Hea-Tae;Shon, Sang-Jin;Kim, Myoung-Ho;Choi, Mi-Ran;Baek, Wook-Jin
    • Resources Recycling
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    • v.16 no.5
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    • pp.19-24
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    • 2007
  • Reefs are the marine structure that can give resting, inhabiting, feeding and nursing spaces for a variety of fishes. Usually artificial reefs are made of cement and steels respectively in Japan as well as in Korea. However since resources deficiency has been getting serious, other materials are taken into consideration for the basic bodies of artificial reefs. About 300 thousand tons of waste agricultural plastic films are generated every yew in Korea, but no effective recycling techniques have been developed. In this sense, artificial reefs made of waste agricultural plastic films are the most representative symbol of the recycled products in the Resource Recycling Era. In particular, since these reefs could be made of the semi-cleaned waste agricultural plastic films that still contain high portion of soil, it is very environmentally friendly not only in manufacturing process but also in using under water. Furthermore they have some evident advantages as follows; 1) high fish swarming effect 2) good initial attachment of the marine growths 3) extremely low corrosion to brine 4) easy adjustment of the gravity 5) economical manufacture, transportation and jettison 6) excellent safety to ecosystem caused by lower elution of toxic substances 7) good recyclable property after application and so on.

A Study on Comparison and Analysis of Motion Sickness Inquiry with MSI Calculation for Training Ship Kaya (실습선 가야호의 멀미도 조사와 MSI 계산의 비교 분석에 관한 연구)

  • Han, Seung-Jae;Ha, Young-Rok;Kim, In-Chul
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.4
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    • pp.412-418
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    • 2014
  • In this paper, for better boarding performance and pleasant boarding sensitivity of the ship, comparison and analysis was performed of motion sickness questionnaire with MSI(Motion Sickness Incidence) calculation based on ship motion theory(Strip Method) due to sea condition, incident angle in main sail way, economic speed, and calculation position of the training ship Kaya of Pukyong National University. On theses works, the rougher sea conditions became, the higher total motion sickness rate was occurred. The weights of vertical acceleration and the rates of MSI were higher at the bridge and the accommodation, which were located farther from the center of gravity of the ship. And effects of the vertical acceleration of the ship were increased in rolling then in head sea. In comparison between motion sickness questionnaire with MSI calculation, when the vertical acceleration increased, the motion sickness rate increased. The location to increase vertical acceleration and the location to cause motion sickness were agreed.