• Title/Summary/Keyword: Center of Gravity

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Image Watermarking Robust to Geometrical Attacks based on Normalization using Invariant Centroid (불변의 무게중심을 이용한 영상 정규화에 기반한 기하학적 공격에 강인한 워터마킹)

  • 김범수;최재각
    • Journal of KIISE:Information Networking
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    • v.31 no.3
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    • pp.243-251
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    • 2004
  • This paper proposes a digital image watermarking scheme, which is robust to geometrical attacks. The method improves image normalization-based watermarking (INW) technique that doesn't effectively deal with geometrical attacks with cropping. Image normalization is based on the moments of the image, however, in general, geometrical attacks bring the image boundary cropping and the moments are not preserved original ones. Thereafter the normalized images of before and after are not same form, i.e., the synchronization is lost. To solve the cropping problem of INW, Invariant Centroid (IC) is proposed in this paper. IC is a gravity center of a central area on a gray scale image that is invariant although an image is geometrically attacked and the only central area, which has less cropping possibility by geometrical attacks, is used for normalization. Experimental results show that the IC-based method is especially robust to geometrical attack with cropping.

Analysis for Bearing Capacity of Paper Ash in Industrial Waste as Filling Material (성토재로서 산업폐기물 제지회의 지지력 분석)

  • Lee, Cheo-Keun;Ahn, Kwang-Kuk;Heo, Yol
    • Journal of the Korean GEO-environmental Society
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    • v.2 no.2
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    • pp.13-22
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    • 2001
  • In this study, centrifuge model tests were fulfilled to investigate the characteristics of bearing capacity of paper ash as a filling material. The model tests were done varying the footing width and gravity level. The settlement and vertical soil pressure by loading were measured. The results from the tests were compared with the one from FLAC program using finite difference method and bearing capacity theory. After all, it was shown that the characteristics of load-settlement represented the local shear failure, which the settlement ratio s/B showed inflection point around 25~30%. As g-level and footing width were increasing, the load strength was increasing. The ultimate bearing capacity from the tests was very closed the results from Terzaghi's theory. As the distance from footing center was increasing, the vertical soil pressure was decreasing. If E/B is higher than 7, the stress by loading was almost increasing. The vertical displacement from loading was the largest one around under the footing and was almost occurred when the depth>4cm and E/B is higher than 5.0.

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The Analysis of Related Variables on the Center of Gravity Deviation: Focus on the Musculoskeletal Pain (중력중심 이동과 관련 변인분석 -근골격계 통증을 중심으로-)

  • Ko, Tae-Sung;Joung, Ho-Bal
    • Physical Therapy Korea
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    • v.10 no.4
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    • pp.85-94
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    • 2003
  • 본 연구에서는 근골격계 통증이 자세유지와 균형능력에 핵심이 되는 중력중심 이동에 미치는 영향에 대해 알아봄으로서, 균형과 자세에 영향을 주는 다양한 요소들에 대한 새로운 접근을 시도해 보고자 한다. I-병원의 입원 및 외래 환자 중 신경계 손상이 없고 중력중심 이동에 직접적인 영향을 줄 수 있는 하지에 정형외과적 장애가 없으며, 전정계 손상이나 시력장애로 인한 균형에 문제가 없이 근골격계 질환으로 요통과 견통을 주소로 하는 71명의 환자(남자 38, 여자 33; 평균연령=44, 표준편차=13.8, 범위=19~79)와 신경계, 근골격계 및 평형감각에 문제가 없는 정상인 30명의 대조군(남자 16, 여자 14; 평균연령=39.2, 표준편차=13.7, 범위=21~72)을 대상으로 전산화된 힘판을 이용하여 중력중심 이동의 궤적을 표준편차값으로 측정하였다. 측정된 중력중심 이동값은 두 군간에 상이한 차이를 보이고 있음이 검증되었다(p<.01). 또 측정된 여러 변수들의 중력중심 이동에 대한 영향력을 알아보기 위해 나이, 체중 및 신장과 중력중심 이동과의 상관분석 결과 중력중심 이동의 15.8%를 체중의 변화에 의한 것으로 설명할 수 있다는 결과를 얻었으며, 그 외의 변수들과의 연관성에 대해선 유의미한 차이가 없었다(p<.01). 결과적으로 근골격계 통증은 올바른 자세유지와 균형유지를 위한 감각통합과 반응과정에 직접, 간접적으로 영향을 미치고 있다. 따라서 중력 중심 이동이 크면 클수록 중심을 잡기 위한 근육활동으로 추가적인 에너지가 사용되고, 편중된 중력중심 이동은 근골격계에 무리한 부담을 주어 통증을 증가시킬 수 있을 것이다. 또 통증으로 인한 중력중심 이동은 이를 보상하기 위해 신체 먼 곳에서의 이차적인 변형을 초래하여 각종 근골격계 증상의 원인이 될 수 있으므로 근골격계에 대한 적절한 치료는 통증을 감소시켜 자세의 이차적인 변형을 막고 자세유지 시 작용하는 근육의 에너지 효율을 높일 수 있을 것으로 사료된다.

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복합재료 선미익 항공기 날개 하중해석

  • Han, Chang-Hwan;Kim, Eung-Tai;Ahn, Seok-Min;Kim, Jin-Won
    • Aerospace Engineering and Technology
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    • v.1 no.1
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    • pp.8-27
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    • 2002
  • In this study, the load analysis of a composite canard aircraft is performed numerically. Excel visual basic program for PC is used to calculate aerodynamic coefficients, loads and moments etc.. The basic data required for the load analysis such as aircraft configuration and dimension, parts and its weight and coordinate etc. are obtained from Catia modeling, measurement or material density. Aircraft weight, center of gravity, inertia moment, structural design speeds, wing load distribution, forces and moments are evaluated by using these data. V-n diagram is also represented for selecting critical loads applied to the wing and fuselage. The V-n diagram is investigated to decide the flight envelope of canard aircraft for design speed VA, VC, VD and load factor +3.8G, -1.52G at maximum weight of 2,573 lbs and sea level. In the future, the results of the wing and fuselage load analysis is to represented by using selected critical loads.

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A Case Study on Center of Gravity Analysis when Performing Uchimata by Posture and Voluntary Resistance Levels of Uke in Judo[ll] (유도 허벅다리걸기 기술발휘 시 받기의 자세와 저항수준에 따른 중심변인 분석 사례연구[II])

  • Kim, Eui-Hwan;Kim, Sung-Sup;Chung, Chae-Wook
    • Korean Journal of Applied Biomechanics
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    • v.15 no.1
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    • pp.237-257
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    • 2005
  • It was to study as a following-research of "A Case Study on Center of Gravity(COG) Analysis when Performing Uchimata(inner thigh reaping throw) by Posture and Voluntary Resistance Levels(VRL) of Uke in Judo[I]". The purpose of this study was to analyze the COG variables when performing uchimata(inner thigh reaping throw) by two postures and voluntary resistance levels(VRL) of uke(reciver) in Judo. The subjects, who were one male judoka(YH) for 1992 Barcelona Olympic Games Olympian(silver medalist), and one male trainee; Y.I.University representative member (SDK), and were filmed on two S-VHS 16mm video cameras(60fields/sec.) through 3-dimensional motion analysis methods, that postures of uke were shizenhontai (straight natural posture) and jigohontai(straight defensive posture), VRL of uke were 0% and 100%, respectively. The kinematical variable was COG variable, distance of COG, and distance of resultant COG between uke and tori(the thrower), velocity and acceleration of COG. The data of this study collection were digitized by SIMI Motion Program computed the mean values and the standard deviation calculated for each variables. When performing uchinmata according to each posture and VRL of uke and classifying. From the data analysis and discussion, the conclusions were as follows : 1. Displacement of COG Subject YH, COG was the highest in kuzushi(balance -breaking), vertical COG was low when following in tsukuri(positioning; set-up), kake(application; execution), and COG was pattern of same character each postures and resistance, respectively. Subject SDK, COG was low from kumikata(engagement positioning) to kake, and COG was that each postures and resistance were same patterns, respectively. Subject YH, SDK, each individual, postures and resistance, vertical COG was the lowest in kake phase, when performing. 2. Distance of COG between uke and tori The distance of COG between uke and tori when performing, subject YH was $0.64{\sim}0.70cm$ in kumikata, $0.19{\sim}0.28cm$ in kake, and SDK was $0.68{\sim}0.72cm$ in kumikata, $0.30{\sim}0.42\;cm$ in kake. SDK was wider than YH. 3. Distance of resultant COG between uke and tori The distance of resultant COG between uke and tori when performing, subject YH was $0.27{\sim}0.73cm$ from kumikata to kake. and SDK was $0.14{\sim}0.34cm$ in kumikata, $0.28{\sim}0.65cm$ in kake. Jigohontai(YH:$0.43{\sim}0.73cm$,SDK:$0.59{\sim}0.65cm$) was more moved than shizenhontai(YH:$0.27{\sim}0.53cm$, SDK: $0.28{\sim}\;0.34cm$). 4. Velocity of COG The velocity of COG when performing uchimata, subject YH was fast anterior-posterior direction in kuzushi, ant.-post. and vertical direction fast in tsukuri and kake. SDK was lateral, ant.-post. and vertical direction in kuzushi, ant.-post. and vertical direction in tsukuri and ant.-post. direction in take, respectively. 5. Acceleration of COG The acceleration of COG when performing uchimata, The trend of subject YH was showed fast vertical direction in kuzushi and tsukuri, ant.-post. and vertical direction fast in kake. The trends of SDK showed lateral direction in kuzushi, lateral and ant.-post. direction in tsukuri and ant.-post. direction in kake, respectively.

Prediction of Heat-treatment Time of Black Pine Log Damaged by Pine Wilt Disease (소나무재선충병 피해를 받은 곰솔 원목의 열처리 소요시간 예측)

  • Han, Yeonjung;Seo, Yeon-Ok;Jung, Sung-Cheol;Eom, Chang-Deuk
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.3
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    • pp.370-380
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    • 2016
  • The black pine logs damaged by pine wilt disease in Jeju-do were heat-treated to extend the utilization of domestic trees damaged by pine wilt disease. The heat-treatment of wood requires wood to be heated to $56^{\circ}C$ for 30 min at the core. The average moisture content and top-diameter of the black pine logs were ranged from 46% to 141% and from 180 mm to 500 mm, respectively. And the basic specific gravity and oven-dry specific gravity of the black pine logs were 0.47 and 0.52, respectively. The time required for heat-treatment at $105^{\circ}C$ temperature was ranged from 7.7 h to 44.2 h, depending on moisture content and top-diameter. The temperature distribution was used to predict the time required for heat-treatment of black pine log with various moisture contents and top-diameters using finite difference method. The thermal properties of wood including the thermal conductivity and specific heat in accordance with moisture content were calculated. Heat transfer coefficient for mixed convection in form of adding natural convection and forced convection was used for heat transfer analysis. The error between the measured and predicted values ranged from 3% to 45%. The predicted times required for heat-treatment of black pine log with 50% moisture content and 200 mm, 300 mm, and 400 mm top-diameter were 10.9 h, 18.3 h, and 27.0 h, respectively. If the initial moisture content of black pine log is 75%, heat treatment times of 13.6 h, 22.5 h, and 32.8 h were predicted in accordance with top-diameter. And if the initial moisture content of black pine log is 100%, heat treatment times of 16.2 h, 26.5 h, and 38.2 h were predicted in accordance with top-diameter. When the physical properties of logs damaged by pine wilt disease are presented, these results can be applicable to the heat-treatment of red pine and Korean pine logs as well.

Physicochemical Characteristics of Tailings from the Various Types of Mineral Deposits (광상유형에 따른 광물찌꺼기의 물리화학적 특성)

  • Lee, Pyeong-Koo;Youm, Seung-Jun;Jung, Myung-Chae;Lee, Jin-Soo;Kwon, Hyun-Ho
    • Economic and Environmental Geology
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    • v.43 no.3
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    • pp.235-248
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    • 2010
  • To construct the standard methods for evaluation of physicochemical characteristics of tailings in Korea, specific gravity, paste pH, grain size, mineral compositions and heavy metal concentrations of total 26 tailings from 21 metallic mines were analyzed. Specific gravity of tailings ranged from 2.61 to 4.31 (avg. 3.04), and sand and silt grain were dominant in the tailings. Ranges of paste pH were 2.1-9.5 in tailings (7.1-9.2 at magmatic, skarn and hydrothermal replacement deposits and 2.1-9.5 at hydrothermal vein deposits). Additionally, hydrothermal vein deposits could be reclassified into three categories: (1) paste pH>7.0, (2) 4.0

(Image Analysis of Electrophoresis Gels by using Region Growing with Multiple Peaks) (다중 피크의 영역 성장 기법에 의한 전기영동 젤의 영상 분석)

  • 김영원;전병환
    • Journal of KIISE:Software and Applications
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    • v.30 no.5_6
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    • pp.444-453
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    • 2003
  • Recently, a great interest of bio-technology(BT) is concentrated and the image analysis technique for electrophoresis gels is highly requested to analyze genetic information or to look for some new bio-activation materials. For this purpose, the location and quantity of each band in a lane should be measured. In most of existing techniques, the approach of peak searching in a profile of a lane is used. But this peak is improper as the representative of a band, because its location does not correspond to that of the brightest pixel or the center of gravity. Also, it is improper to measure band quantity in most of these approaches because various enhancement processes are commonly applied to original images to extract peaks easily. In this paper, we adopt an approach to measure accumulated brightness as a band quantity in each band region, which Is extracted by not using any process of changing relative brightness, and the gravity center of the region is calculated as a band location. Actually, we first extract lanes with an entropy-based threshold calculated on a gel-image histogram. And then, three other methods are proposed and applied to extract bands. In the MER method, peaks and valleys are searched on a vertical search line by which each lane is bisected. And the minimum enclosing rectangle of each band is set between successive two valleys. On the other hand, in the RG-1 method, each band is extracted by using region growing with a peak as a seed, separating overlapped neighbor bands. In the RG-2 method, peaks and valleys are searched on two vertical lines by which each lane is trisected, and the left and right peaks nay be paired up if they seem to belong to the same band, and then each band region is grown up with a peak or both peaks if exist. To compare above three methods, we have measured the location and amount of bands. As a result, the average errors in band location of MER, RG-1, and RG-2 were 6%, 3%, and 1%, respectively, when the lane length is normalized to a unit value. And the average errors in band amount were 8%, 5%, and 2%, respectively, when the sum of band amount is normalized to a unit value. In conclusion, RG-2 was shown to be more reliable in the accuracy of measuring the location and amount of bands.

Composition Ratio Analysis of Transesterification Products of Olive Oil by Using Thin Layer Chromatography and Their Applicability to Cosmetics (올리브 오일의 에스터 교환반응 생성물의 TLC를 이용한 조성비 분석 및 화장품에의 응용가능성 평가)

  • Park, So Hyun;Shin, Hyuk Soo;Kim, A Rang;Jeong, Hyo Jin;Xuan, Song Hua;Hong, In Kee;Lee, Dae Bong;Park, Soo Nam
    • Applied Chemistry for Engineering
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    • v.29 no.3
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    • pp.342-349
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    • 2018
  • In this study, the physicochemical properties, emulsifying capacity, moisture content and cytotoxicity of the composite material produced by transesterification reactions of the olive oil (olive oil esters) were investigated for cosmetic applications. Olive oil esters with short (S) and long (L) reaction times were studied. From the TLC-image analysis, composition ratios of the olive oil esters S were found to be 5.2, 24.1, 46.4, and 21.9% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. Those of the olive oil esters L were 4.1, 24.7, 40.6, and 28.8% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. The iodine value, acid value, saponification value, unsaponified matter, refractive index, and specific gravity were determined and purity tests were also carried out and normalized to establish standards and testing methods for using olive oil esters in cosmetics. To evaluate their emulsifying capacities, the O/W emulsion was prepared without surfactants and the formation of the emulsified particles were confirmed. After 5 days of applying the olive oil esters to human skin, the skin moisture retention was improved by 13.1% from the initial state. For the evaluation of toxicity on human skin cells, the olive oil esters showed 90% or more of the cell viability at $0.2-200{\mu}g/mL$. These results suggested that olive oil esters can be applied as natural/non-toxic ingredients to cosmetics industries.

Model of Water, Energy and Waste Management for Development of Eco-Innovation Park ; A Case Study of Center for Research of Science and Technology "PUSPIPTEK," South Tangerang City, Indonesia

  • Setiawati, Sri;Alikodra, Hadi;Pramudya, Bambang;Dharmawan, Arya Hadi
    • World Technopolis Review
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    • v.3 no.2
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    • pp.89-96
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    • 2014
  • Center for Research of Science and Technology ("PUSPIPTEK") has 460 hectares land area, still maintained as a green area with more than 30% green space. There are 47 centers for research and testing technology, technology-based industries, and as well as public supporting facilities in PUSPIPTEK area. Based on the concepts developed to make this area as an ecological region, PUSPIPTEK can be seen as a model of eco-innovation. The purpose of this research is to develop a model of water, energy and waste management with eco-innovation concept. As a new approach in addressing environmental degradation and maintaining the sustainability of ecosystem, studies related to eco-innovation policy that combines the management of water, energy and waste in the region has not been done. In order to achieve the objectives of the research, a series of techniques for collecting data on PUSPIPTEK existing conditions will be carried out, which includes utilities data (water, electricity, sewage) and master plan of this area. The savings over the implementation of the concept of eco-innovation in water, energy, and waste management were calculated and analyzed using quatitative methods. The amount of cost savings and feasibility were then calculated. Eco innovation in water management among other innovations include the provision of alternative sources of water, overflow of rain water and water environments utilization, and use of gravity to replace the pumping function. Eco-innovation in energy management innovations include the use of LED and solar cell for air conditioning. Eco-innovation in waste management includes methods of composting for organic waste management. The research results: (1) The savings that can be achieved with the implementation of eco innovation in the water management is Rp. 3,032,640 daily, or Rp.1,106,913,600 annually; (2) The savings derived from the implementation of eco innovation through replacement of central AC to AC LiBr Solar Powered will be saved Rp.1,933,992,990 annually and the use of LED lights in the Public street lighting PUSPIPTEK saved Rp.163,454,433 annually; (3) Application of eco innovation in waste management will be able to raise awareness of the environment by sorting organic, inorganic and plastic waste. Composting and plastic waste obtained from the sale revenue of Rp. 44,016,000 per year; (4) Overall, implementation of the eco-innovation system in PUSPIPTEK area can saves Rp. 3,248,377,023 per year, compared to the existing system; and (5)The savings are obtained with implementation of eco-innovation is considered as income. Analysis of the feasibility of the implementation of eco-innovation in water, energy, and waste management in PUSPIPTEK give NPV at a 15% discount factor in Rp. 3,895,228,761; 23.20% of IRR and 4.48 years of PBP. Thus the model of eco-innovation in the area PUSPIPTEK is feasible to implement.