• Title/Summary/Keyword: Balance-beam

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Satellite Laser Ranging System at Geochang Station

  • Lim, Hyung-Chul;Sung, Ki-Pyoung;Yu, Sung-Yeol;Choi, Mansoo;Park, Eunseo;Park, Jong-Uk;Choi, Chul-Sung;Kim, Simon
    • Journal of Astronomy and Space Sciences
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    • v.35 no.4
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    • pp.253-261
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    • 2018
  • Korea Astronomy and Space Science Institute (KASI) has been developing the space optical and laser tracking (SOLT) system for space geodesy, space situational awareness, and Korean space missions. The SOLT system comprises satellite laser ranging (SLR), adaptive optics (AO), and debris laser tracking (DLT) systems, which share numerous subsystems, such as an optical telescope and tracking mount. It is designed to be capable of laser ranging up to geosynchronous Earth orbit satellites with a laser retro-reflector array, space objects imaging brighter than magnitude 10, and laser tracking low Earth orbit space debris of uncooperative targets. For the realization of multiple functions in a novel configuration, the SOLT system employs a switching mirror that is installed inside the telescope pedestal and feeds the beam path to each system. The SLR and AO systems have already been established at the Geochang station, whereas the DLT system is currently under development and the AO system is being prepared for testing. In this study, the design and development of the SOLT system are addressed and the SLR data quality is evaluated compared to the International Laser Ranging Service (ILRS) tracking stations in terms of single-shot ranging precision. The analysis results indicate that the SLR system has a good ranging performance, to a few millimeters precision. Therefore, it is expected that the SLR system will not only play an important role as a member of the ILRS tracking network, but also contribute to future Korean space missions.

Shear strength prediction of high strength steel reinforced reactive powder concrete beams

  • Qi-Zhi Jin;Da-Bo He;Xia Cao;Feng Fu;Yi-Cong Chen;Meng Zhang;Yi-Cheng Ren
    • Advances in concrete construction
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    • v.17 no.2
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    • pp.75-92
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    • 2024
  • High Strength steel reinforced Reactive Powder Concrete (RPC) Beam is a new type of beams which has evident advantages than the conventional concrete beams. However, there is limited research on the shear bearing capacity of high-strength steel reinforced RPC structures, and there is a lack of theoretical support for structural design. In order to promote the application of high-strength steel reinforced RPC structures in engineering, it is necessary to select a shear model and derive applicable calculation methods. By considering the shear span ratio, steel fiber volume ratio, longitudinal reinforcement ratio, stirrup ratio, section shape, horizontal web reinforcement ratio, stirrup configuration angle and other variables in the shear test of 32 high-strength steel reinforced RPC beams, the applicability of three theoretical methods to the shear bearing capacity of high-strength steel reinforced RPC beams was explored. The plasticity theory adopts the RPC200 biaxial failure criterion, establishes an equilibrium equation based on the principle of virtual work, and derives the calculation formula for the shear bearing capacity of high-strength steel reinforced RPC beams; Based on the Strut and Tie Theory, considering the softening phenomenon of RPC, a failure criterion is established, and the balance equation and deformation coordination condition of the combined force are combined to derive the calculation formula for the shear bearing capacity of high-strength reinforced RPC beams; Based on the Rankine theory and Rankine failure criterion, taking into account the influence of size effects, a calculation formula for the shear bearing capacity of high-strength reinforced RPC beams is derived. Experimental data is used for verification, and the results are in good agreement with a small coefficient of variation.

A Study on the Nutritional Assessment of Early Childhood Using Mid-Upper-Arm Circumference (상박위(上膊圍)에 의(依)한 성장기(成長期) 아동(兒童)에 영양상태(營養狀態)의 판정(判定)에 관(關)한 연구(硏究))

  • Tchai, B.S.;Nam, Y.K.;Chung, Y.J.
    • Journal of Nutrition and Health
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    • v.8 no.4
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    • pp.9-14
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    • 1975
  • Growth retardation and a variable degree of body disproportion are recognized features of malnutrition, and mild and moderate protein-calorie malnutrition(PCM). Among the various body measurements suggested to assess the prevalence of all grades of PCM as judged by growth retardation and by body disproportion, the 'mid-upper-arm circumference'-abbreviated to 'arm-circumference' has been suggested as a potential useful simple field index for the assessment of PCM showing that the measurement would give composite information simultaneously on three important effects on PCM-deficit in the muscle protein reservoirs, availability of calorie stores in the form of subcutaneous fat, and growth failure. And this is selected because of its easy accessibility, and less involvement with clinical edema. This study is conducted to make a comparison between the percentage of Korean weight for age standards and the percentage of mid-upper-arm circumference for age standards of 175 preschool children aged $3{\sim}72$ months who are selected among the low-income residents in Seoul. In this study, a comparison is made between the results obtained by expressing the observed weight of the child as a percentage of Korean standard, referred to as 'weight-for-age' and the observed arm-circumference expressed as a percentage of the age-specific arm standard of Jelliffe, referred to as 'arm-for-age'. All the measurements were taken following the techniques described by Jelliffe. The left mid upper arm was measured using a glass-fibre tape and the Fairbanks Morse beam balance was used for weighing. 80% level of weight for age Korean standard and 85% level of arm for are Jelliffe standard were used as an upper borderline limit for PCM. Comparing the 80% weight-for-age and the 85% arm-for-age standard as an upper limit for PCM, for children aged $3{\sim}72$ months, results in 84.6% agreement with the sensitivity of 86.4% and its specificity of 83.5%. If arm circumference alone had been measured and judgement made on this basis, then only 5.1% of the children would have been 'wrongly' classified. And there is a moderately close correlation between arm circumference and weight for age as the data in Table 4 shows. The problem therefore lies in the standard for arm circumference in normal children and in determining what is the lower limit of normal. Once this is clearly difined, one can rely more confidently on arm circumference measurements alone for the nutritional assessment of early childhood.

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A Study on Ecology theory and Environment theory Research that is Loocked in Hayao Miyazaki work (미야자키 하야오(宮崎 駿)작품에 투영된 생태론과 환경론 연구)

  • Lee, Seung-Jae
    • Cartoon and Animation Studies
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    • s.44
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    • pp.183-209
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    • 2016
  • Hayao Miyazaki's product, , is evaluated that his work until present that product point of view and commercial point of view are highly filled at the same time. Miyazaki's showed new public entertainment possibility in genre that is animation inventing highest-grossing domestic film in Japan's history until it was taken over by another Miyazaki work. Also, it can high evaluate that not that see for interest simply beam about environment and human who writer has to spectator deep self-examination and way of problem pulling comprehension without burden through resected reflex which is not exigent delivery sympathy form. Analyzing his product, , ,, , , , this research allowed purpose to recognize that he present the alternative after arranges intent subject how and institute problem. And do to study whether his though and ideology met with viewpoints of ecologism and environment(environmentalism) in work how. There are his countenance have theme that is certain in Miyazaki director's works. If summarize had handled subject meantime, it is , , , etc. This subjects are that go first at importance order among problems which we face, it is that human desires essentially. If balance of society system that regulate various economical, moral value system and desire to our society is set, our society is that can become little more near in nature mode of life.

Neuroprotective Effect of $NeuBo153^{\circledR}$ on Transient Focal Cerebral Ischemia in Rats ($NeuBo153^{\circledR}$의 중풍동물 모델에 대한 뇌신경 보호효과)

  • Bu, Young-Min;Oh, Se-Nam;Hwang, Man-Ki;Chung, Jin-Hee;Lee, Dae-Hee;Park, Young-Mee;Kim, Mi-Yon;Kim, Zhen-Hwa;Kim, Ho-Cheol
    • The Korea Journal of Herbology
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    • v.21 no.2
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    • pp.151-158
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    • 2006
  • Objectives : The purpose of the present study is to observe the neuroprotective effect of the $NeuBo153^{\circledR}$ on transient focal cerebral ischemia in rats. Methods : $NeuBo153^{\circledR}$ was made by mixing the herbs, mainly the root of Panax ginseng, the root of Rehmannia glutinosa and Poria cocos, the stem bark of Acanthopanax senticosus, the root of Scutellaria baicalensis and Mel, and heating for 96 hours. Transient Focal cerebral ischemia (2 h of ischemia, 22 h of reperfusion) was induced by intraluminal suture method with SD rats. Sensory motor function was tested by rotarod test, prehensile traction test, beam balance test and foot fault test at 24 h after ischemia. The brain slices were stained by 2% 2, 3, 5-triphenyltetrazolium chloride and the infarct volume was measured by graphic analyzer at 24 h after ischemia. Results : $NeuBo153^{\circledR}$ treated group did not show significant differences compared with vehicle treated group in body temperature. Oral administration of $NeuBo153^{\circledR}$ reduced brain infarct volume by 29.7% compared with vehicle treated group. $NeuBo153^{\circledR}$ also showed protective effects on sensory motor functional deficits. Conclusion : $NeuBo153^{\circledR}$ treatment reduced brain damage and improved functional deficits induced by MCAo. It showed neuroprotective effects even when treatment was relayed 2 h after injury. Further research is required to evaluating long term functional recovery am accurate therapeutic range and mechanisms.

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Gaussian Noise Reduction Method using Adaptive Total Variation : Application to Cone-Beam Computed Tomography Dental Image (적응형 총변이 기법을 이용한 가우시안 잡음 제거 방법: CBCT 치과 영상에 적용)

  • Kim, Joong-Hyuk;Kim, Jung-Chae;Kim, Kee-Deog;Yoo, Sun-K.
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.49 no.1
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    • pp.29-38
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    • 2012
  • The noise generated in the process of obtaining the medical image acts as the element obstructing the image interpretation and diagnosis. To restore the true image from the image polluted from the noise, the total variation optimization algorithm was proposed by the R.O. F (L.Rudin, S Osher, E. Fatemi). This method removes the noise by fitting the balance of the regularity and fidelity. However, the blurring phenomenon of the border area generated in the process of performing the iterative operation cannot be avoided. In this paper, we propose the adaptive total variation method by mapping the control parameter to the proposed transfer function for minimizing boundary error. The proposed transfer function is determined by the noise variance and the local property of the image. The proposed method was applied to 464 tooth images. To evaluate proposed method performance, PSNR which is a indicator of signal and noise's signal power ratio was used. The experimental results show that the proposed method has better performance than other methods.

Fabrication and Electromechanical Behaviors of a SWNT/PANi Composite Film Actuator (탄소나노튜브/도전성폴리머 복합재 엑츄에이터의 제조 및 특성실험)

  • Zhang, Shuai;Kim, Cheol
    • Composites Research
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    • v.19 no.5
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    • pp.7-11
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    • 2006
  • The improved SWNTs/PANi composite actuator films applicable to an artificial muscle were fabricated successfully using a new process of manufacture that consists of 90% pure single-walled carbon nanotubes (SWNT) and chemical polymerization. PANi is electrically conducting polyaniline polymer. The conductivities of the composite SWNTs/PANi film-type actuators and the pure PANi films fabricated were measured as 56.15 S/cm and 17.38 S/cm, respectively, by the 4-prove method. The conductivity of the composite actuator is 3.2 times higher than the pure PANi film. The fabricated composite actuator showed higher conductivity than any other similar ones. The quality of samples was investigated by an electron scanning microscope (SEM). To measure the actuating strains, a specially designed beam balance apparatus was developed and strains of the composite actuators was measured by a laser displacement sensor subjected to electric currents. During the operation, the sample was soaked in the $NaNO_3$ solution and the sine-wave voltage in the range of $+1V{\sim}-1V$ was applied. The length of the composite actuator changed from $l_0=12.690$ mm to $l_1=12.733$ so that the change of length was l=0.043 mm and the strain was 0.34 %. This is a very high strain for this kind of a composite actuator. Other result reported by Tahhan showed 0.23 % strain, so that the present result is improved by 48%.

A Study on Mechanical Errors in Cone Beam Computed Tomography(CBCT) System (콘빔 전산화단층촬영(CBCT) 시스템에서 기계적 오류에 관한 연구)

  • Lee, Yi-Seong;Yoo, Eun-Jeong;Kim, Seung-Keun;Choi, Kyoung-Sik;Lee, Jeong-Woo;Suh, Tae-Suk;Kim, Joeng-Koo
    • Journal of radiological science and technology
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    • v.36 no.2
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    • pp.123-129
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    • 2013
  • This study investigated the rate of setup variance by the rotating unbalance of gantry in image-guided radiation therapy. The equipments used linear accelerator(Elekta Synergy TM, UK) and a three-dimensional volume imaging mode(3D Volume View) in cone beam computed tomography(CBCT) system. 2D images obtained by rotating $360^{\circ}$and $180^{\circ}$ were reconstructed to 3D image. Catpan503 phantom and homogeneous phantom were used to measure the setup errors. Ball-bearing phantom was used to check the rotation axis of the CBCT. The volume image from CBCT using Catphan503 phantom and homogeneous phantom were analyzed and compared to images from conventional CT in the six dimensional view(X, Y, Z, Roll, Pitch, and Yaw). The variance ratio of setup error were difference in X 0.6 mm, Y 0.5 mm Z 0.5 mm when the gantry rotated $360^{\circ}$ in orthogonal coordinate. whereas rotated $180^{\circ}$, the error measured 0.9 mm, 0.2 mm, 0.3 mm in X, Y, Z respectively. In the rotating coordinates, the more increased the rotating unbalance, the more raised average ratio of setup errors. The resolution of CBCT images showed 2 level of difference in the table recommended. CBCT had a good agreement compared to each recommended values which is the mechanical safety, geometry accuracy and image quality. The rotating unbalance of gentry vary hardly in orthogonal coordinate. However, in rotating coordinate of gantry exceeded the ${\pm}1^{\circ}$ of recommended value. Therefore, when we do sophisticated radiation therapy six dimensional correction is needed.