• 제목/요약/키워드: Hu moment

검색결과 63건 처리시간 0.025초

조영제 사용이 양성자 Range와 SOBP(Spread-Out Bragg peak)에 미치는 영향 (Influence of Intravenous Contrast Medium on Proton range and SOBP(Spread-Out Bragg peak))

  • 김호식;최승오;김은숙;전상민;염두석
    • 대한방사선치료학회지
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    • 제26권2호
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    • pp.183-189
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    • 2014
  • 목 적 : 조영제는 CT모의치료시 정상조직과 악성종양을 구분하는데 뛰어난 대조도를 제공하기 때문에 CT모의치료에 널리 사용하고 있다. 하지만 조영제는 치료계획 CT에서 일시적으로 존재하기 때문에, 치료계획과 실제 치료 사이에는 Hounsfield Unit(HU)의 차이가 발생하게 된다. 이에 본 연구에서는 조영제 사용으로 인한 HU의 변화가 양성자 치료계획에 미치는 영향을 확인 하고자한다. 대상 및 방법 : 20명의 간암 환자에게서 Phase에 따른 HU값의 변화를 측정하였다, 그리고 5명의 양성자치료계획에서 HU변화에 따른 Range와 Spread-Out Bragg peak(SOBP)의 변화를 살펴보았다. Hand made water phantom을 이용하여 깊이와 HU의 변화에 따른 Range와 SOBP의 변화를 확인하였다. 결 과 : 20명 간암 환자의 HU 변화(Pre contrast, Arterial phase, Porta phase)는 간 조직에서 ($58{\pm}5.7$, $75{\pm}9.5$, $117{\pm}14.6$)이었으며 대동맥에서($40{\pm}6.1$, $279{\pm}49.0$, $154{\pm}22.8$)이었다. 5명의 간암 양성자치료계획에서 HU 변화에 따른 Range 변화는 평균 2.5 mm, SOBP 변화는 평균 1.4 mm 이었다. Hand made water phantom study에서는 HU가 증가함에 따라 Range는 감소되었고 SOBP는 줄어들었다. 결 론 : 양성자 치료계획에서 HU값의 변화는 양성자 Range와 SOBP를 변화시켰다. 실제 양성자 빔에서 HU 변화에 따른 Range와 SOBP의 변화에 대한 추가적인 연구가 필요할 것으로 사료 된다.

사람 보행시 발바닥의 힘정보를 측정하기 위한 지능형 신발시스템 개발 (Development of lntelligent Shoe System to Measure Applied Force/Moment on the Sole of a Foot during Human Walking)

  • 김갑순;김현민;허덕찬
    • 한국정밀공학회지
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    • 제25권7호
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    • pp.79-86
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    • 2008
  • This paper describes the development of wearing intelligent shoe system to measure applied forces and moments (ground reaction forces and moments) on the soles of feet during human walking. In order to walk safely, robot must get the intelligent feet with 6-axis force/moment sensors (Fx sensor (x-direction force sensor), Fy sensor, Fz sensor, Mx sensor (Mx : x-direction moment sensor), My sensor, and Mz sensor) and detect the forces and moments data from the sensors. And the feet must be controlled with the data and controllers. While a human is walking, the forces and moments should be measured and analyzed for robot's intelligent feet. Therefore, the wearing intelligent shoe system should be developed. In this paper, four 6-axis farce/moment sensors and two high speed measuring devices were designed and fabricated, and the wearing intelligent shoe system was made using these. The characteristic tests of the wearing intelligent shoe system were performed, and the forces and moments were detected using it.

Analysis of Magnetic Dipole Moment for a 300-W Solar-Cell Array

  • Shin, Goo-Hwan;Kim, Dong-Guk;Kwon, Se-Jin;Lee, Hu-Seung
    • Journal of Astronomy and Space Sciences
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    • 제36권3호
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    • pp.181-186
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    • 2019
  • The attitude information of spacecraft can be obtained by the sensors attached to it using a star tracker, three-axis magnetometer, three-axis gyroscope, and a global positioning signal receiver. By using these sensors, the spacecraft can be maneuvered by actuators that generate torques. In particular, electromagnetic-torque bars can be used for attitude control and as a momentum-canceling instrument. The spacecraft momentum can be created by the current through the electrical circuits and coils. Thus, the current around the electromagnetic-torque bars is a critical factor for precisely controlling the spacecraft. In connection with these concerns, a solar-cell array can be considered to prevent generation of a magnetic dipole moment because the solar-cell array can introduce a large amount of current through the electrical wires. The maximum value of a magnetic dipole moment that cannot affect precise control is $0.25A{\cdot}m^2$, which takes into account the current that flows through the reaction-wheel assembly and the magnetic-torque current. In this study, we designed a 300-W solar cell array and presented an optimal wire-routing method to minimize the magnetic dipole moment for space applications. We verified our proposed method by simulation.

Finite element analysis of CFT columns subjected to pure bending moment

  • Hu, H.T.;Su, F.C.;Elchalakani, M.
    • Steel and Composite Structures
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    • 제10권5호
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    • pp.415-428
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    • 2010
  • Proper material constitutive models for concrete-filled tube (CFT) columns of circular cross section and subjected to pure bending moment are proposed. These material models are implemented into the Abaqus finite element program and verified against experimental data. It has been shown that the steel tube does not provide good confining effect to the concrete core when the CFT columns is subjected to pure bending moment. When the diameter-to-thickness ratio of the CFT columns is small, the behavior of the CFT column is the same as the steel tube without a concrete core.

Effects of pulse-like nature of forward directivity ground motions on the seismic behavior of steel moment frames

  • Mansouri, Iman;Shahbazi, Shahrokh;Hu, Jong Wan;Moghaddam, Salar Arian
    • Earthquakes and Structures
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    • 제17권1호
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    • pp.1-15
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    • 2019
  • In the structures with high level of ductility, the earthquake energy dissipation in structural components is an important factor that describes their seismic behavior. Since the connection details play a major role in the ductile behavior of structure, in this paper, the seismic response of 3-, 5- and 8-story steel special moment frames (SMFs) is investigated by considering the effects of panel zone modeling and the influence of forward-directivity near-field ground motions. To provide a reasonable comparison, selected records of both near and far-field are used in the nonlinear time-history analysis of models. The results of the comparison of the median maximum inter-story drift under excitation by near-field (NF) records and the far-field (FF) ground motions show that the inter-story drift demands can be obtained 3.47, 4.86 and 5.92 times in 3-, 5- and 8-story structures, respectively, undergoing near-field earthquakes.

지능형 로봇 발을 위한 6 축 힘/모멘트센서 개발 (Development of 6-axis force/moment sensor for an intelligent robot's foot)

  • 김갑순;신희준;허덕찬;윤정원
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.1097-1102
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    • 2007
  • This paper describes the development of 6-axis force/moment sensor for an intelligent robot's foot. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz to itself. The applied forces and moments should be measured from a 6-axis force/moment sensor attached to a humanoid robot's foot(ankle). They in the published paper already have some disadvantage in the size of the sensor, the rated output and so on. The rated output of each component sensor (6-axis force/moment sensor) is very important to design the 6-axis force/moment sensor for precision measurement. Therefore, each sensor should be designed to be gotten similar the rated output under each rated load. So, the sensing elements of the 6-axis force/moment sensor should get lots of design variables. Also, the size of 6- axis force/moment sensor is very important for mounting to robot's foot. In this paper, a 6-axis force/moment sensor for perceiving forces and moments in a humanoid robot's foot was developed using many PPBs (parallel plate-beams). The structure of the sensor was newly modeled, and the sensing elements (plate-beams) of the sensor were designed using FEM (Finite Element Method) analysis. Then, the 6-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements, and the characteristic test of the developed sensor was carried out. The rated outputs from FEM analysis agree well with that from the characteristic test.

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Developpe devant 수행시 하지 관절 모멘트 분석 (Analysis on lower extremity joint moment during a developpe devant)

  • 박기자;신성휴;권문석;김태완;이형나
    • 한국운동역학회지
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    • 제14권1호
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    • pp.133-144
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    • 2004
  • The purpose of this study was to analyze the joint moment on lower extremity during a developpe devant. Data were collected by Kwon3D, KwonGRF program. Two professional modem female dancers were participated in this experiment. Subjects performed a developpe devant in meddle heights. On the axes of X, Y, Z, it was shown that the maximum joint moment was occurred in hip joint. The moments are plotted during developpe devant. The ankle muscles generate a plantar flexion moment and the knee muscles generate a flexion moment and The hip muscles generate a extension moment. So these muscles of joint muscles were known to play a key role in keeping the body balance while doing developpe devant. In addition adduction moment occurred at hip, knee, an ankle in the order of amount, we could assume from this data that him out motion started from the hip joint. There was small active turn out possible below the hip joint. A small amount of extra turn out could be obtained when standing because of flexion between the foot and floor, which could be used to give a passive external rotation force to the whole leg and this could produce a rotation between the knee and foot. This passive external rotation could produce very damaging results. Therefore, lower extremity joint muscles such as hip, knee, and ankle muscle should be trained to keep the body balance and prevent injury during developpe devant performance. And for the safe and perfect turn ort performance, hip joint abduction, the most important external rotating muscle for him out is needed to train and full stretching should be done in advance.

Hu 불변 모멘트를 이용한 장문인식 알고리즘 (Palmprint Identification Algorithm using Hu Invariant Moments)

  • 신광규;이강현
    • 전자공학회논문지CI
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    • 제42권2호
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    • pp.31-38
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    • 2005
  • 최근 생체인식기반의 개인인증은 인증의 자동화와 높은 성능으로 개인인증의 효과적인 방법으로 대두되고 있다. 본 논문에서는 Hu 불변 모멘트에 기초한 장문인식 방법을 제안하였다. 그리고 장문인식 알고리즘의 전체 실행 속도를 높여 효율성 있는 장문인식 시스템을 설계하기 위하여 저해상도(75dpi) 장문이미지$(5.5cm\times5.5cm)$를 사용한다. 제안된 시스템은 두 부분으로 이루어져 있는데 정확한 장문이미지를 획득하기 위한 장문 고정장치와 장문인증을 효과적으로 처리할 수 있는 알고리즘으로 구성되어 있다. 그리고 장문인증 단계는 3회로 제한되며, 그 결과 임계값 0.001일 때 FAR은 $(5.5cm\times5.5cm)$, GAR은 $98.1\%$이다. 이는 [3]과 비교하여, FAR은 $0.002\%$, GAR은 $0.1\%$ 향상되었음을 확인하였다.

중국 당나라 여성 호복의 특성을 활용한 패션디자인 - 3D 가상착의를 활용하여 - (Development of fashion design applying the characteristics of women's Hu clothing from Tang dynasty in China - Utilizing the 3D virtual clothing program -)

  • 주자항;이연희
    • 복식문화연구
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    • 제31권1호
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    • pp.124-140
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    • 2023
  • This study analyzes traditional women's Hu costumes of the Tang dynasty, and deploys a creative fashion design to converge contemporary and traditional styles. In this costume, women wear a robe with striped or plain patterns in the lower part of the pants, and it appears frequently in red and yellow colors. Depending on the sleeve, it is either a round collar or a turn down collar robe. In the Hu hat, the huntuomao and juanyanxumao were leather and mili and weimao were used to prevent the sand from flowing. This study uses the CLO 3D program with the "moment" theme based on the Hu costume for women to deploy 4 pairs of fashion design and to produce works for 2 pairs. The 3D virtual clothing program demonstrates important effects in design deployment and pattern arrangement through its efficiency and convenience of clothing production. The CLO 3D program was closely combined with the 2D design and the 3D affect, and it heightened the efficiency in saving the processing time and energy of the sample clothes. Through facilitating the 3D digital fashion design, the production may reduce time needed and contribute to an effective economy, and it may compare digital fashion design to actual products as well as illustrate the potential of digital fashion design.