• Title/Summary/Keyword: counter-rotation

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Development of the Rack-Bar Type Sluice Gate Applying the Hydrostatic Transmission (정유압식 래크바형 수문권양기의 개발)

  • Lee, Seong-Rae
    • Transactions of The Korea Fluid Power Systems Society
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    • v.7 no.4
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    • pp.15-22
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    • 2010
  • The typical hydraulic hoisting system of the rack-bar type sluice gate is composed of a hydraulic supply unit using an uni-directional pump, a direction control valve, a hydraulic motor, a counter balance valve, and flow control valves. Here, the hydrostatic transmission is applied to the hoisting system of rack-bar type sluice gate to simplify the operation of gate such that the upward and downward direction of gate is simply controlled by the direction of pump rotation. The new hydraulic hoisting system is composed of a bi-directional pump, a hydraulic motor, a counter balance valve, two check valves, two pilot-operated check valves, two relief valves and a shuttle valve. The characteristics of a suggested system are analyzed by computer simulations and experiments.

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Development of the Rack-Bar Type Sluice Gate Applying the Hydrostatic Transmission (정유압식 래크바형 수문권양기의 개발)

  • Lee, Seong-Rae
    • 유공압시스템학회:학술대회논문집
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    • 2010.06a
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    • pp.86-92
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    • 2010
  • The typical hydraulic hoisting system of the rack-bar type sluice gate is composed of a hydraulic supply unit using an uni-directional pump, a direction control valve, a hydraulic motor, a counter balance valve, and flow control valves. Here, the hydrostatic transmission is applied to the hoisting system of rack-bar type sluice gate to simplify the operation of gate such that the upward and downward direction of gate is simply controlled by the direction of pump rotation. The new hydraulic hoisting system is composed of a bi-directional pump, a hydraulic motor, a counter balance valve, two check valves, two pilot-operated check valves, two relief valves and a shuttle valve. The characteristics of a suggested system are analyzed by computer simulations and experiments.

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The influence of horizontal cephalic rotation on the deviation of mandibular position

  • Katayama, Naoto;Koide, Kaoru;Koide, Katsuyoshi;Mizuhashi, Fumi
    • The Journal of Advanced Prosthodontics
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    • v.10 no.6
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    • pp.401-407
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    • 2018
  • PURPOSE. When performing an occlusal procedure, it is recommended that the patient should be sitting straight with the head in a natural position. An inappropriate mandibular position caused by an incorrect occlusal record registration or occlusal adjustment can result in damaged teeth and cause functional disorders in muscles and temporomandibular joints. The purpose of this study was to clarify the influence of horizontal cephalic rotation on mandibular position by investigating the three-dimensional positions of condylar and incisal points. MATERIALS AND METHODS. A three-dimensional jaw movement measurement device with six degrees of freedom (the WinJaw System) was used to measure condylar and incisal points. The subjects were asked to sit straight with the head in a natural position. The subjects were then instructed to rotate their head horizontally $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, $40^{\circ}$, $50^{\circ}$and $60^{\circ}$ in the right or left direction. RESULTS. The results indicated that horizontal cephalic rotation made the condyle on the rotating side shift forward, downward, and toward the inside, and the condyle on the counter rotating side shift backward, upward, and toward the outside. Significant differences in deviations were found for angles of rotation higher than $20^{\circ}$. The incisal point shifted in the forward and counterrotating directions, and significant differences were found for angles of rotation higher than $20^{\circ}$. CONCLUSION. The mandibular position was altered by horizontal cephalic rotations of more than $20^{\circ}$. It is essential to consider the possibility of deviation of the mandibular position during occlusal procedures.

VARIATION IN THE GROWTH PATTERN OF THE FACE: A LONGITUDINAL COMPUTERIZED RECTILINEAR CEPHALOMETRIC STUDY (안면골의 성장회전에 관한 연구)

  • Kim, Il-Bong;Sung, Jae-Hyun;Chung, Kyu-Rhim
    • The korean journal of orthodontics
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    • v.15 no.1
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    • pp.123-140
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    • 1985
  • Variation in the facial pattern and effect of the rotational jaw growth on the facial proportion were studied in serial cephalometric radiographs of 40 Korean children (25 boys, 15 girls) ranging in age from 6 to 13 years. According to Y-axis (N-S-Gn) growth change during the 7 years of period, the subject who had exhibited 'wave-like' manner of Y-axis growth change within ${\pm}\;2^{\circ}$ was classified to the Parallelwise group and the subject who had exhibited Y-axis increase more than $+2^{\circ}$ was classified to the Clockwise rotation group and the subject who had exhibited Y-axis decrease more than $-2^{\circ}$ was classified to the Counterclockwise rotation group. For the comparison of each group, a total of 22 morphologic variables were employed and the data were analyzed by means of computer morphometrics and statistical methods. On the basis of the finding of this study, the following trends were established. 1. The Parallelwise group was $75\%$, the Clockwise rotation group was $12.5\%$ and the Counter-clockwise rotation group was $12.5\%$. 2. The growth pattern of cranial base was related to the rotation of mandible. 9. Maxillary prognathism was occured in the Counterclockwise rotation group and the rotation of palatal plane was occured in the Clockwise rotation group. 4. Mandibular prognathism was occured in the Parallelwise and the Counterclockwise rotation groups, especially in the Counterclockwise rotation group. 5. The degree of maxillo-mandibular divergency was constant in the Clockwise rotation group but decreased in the Counterclockwise rotation and the Parallelwise groups, especially in the Counterclockwise group. 6. There were no differences in the size of the anterior upper facial height (N-ANS) and the posterior lower facial height ((Go-Me)-PNS) but there were differences in the size of the anterior lower facial height (ANS-Me) and the posterior upper facial height ((S-N)-PNS) between each group. 7. The growth increment and the size of the facial depth was not related to the growth pattern of the face but the growth increment and the size of the facial height was related to the growth pattern of the face. 8. Proportional change due to the facial growth rotation was concentrated in the anterior lower face. 9. The most apparent difference between each group was happened in the size of the posterior cranial base (S-Ba) and the facial length (S-Gn).

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Heat Transfer Characteristics in a Leading Edge Cooling Channel of a Turbine Blade with Various Rib Arrangements (터빈 기익 선단부에 설치된 냉각유로에서의 요철 배열에 따른 열전달 특성)

  • Lee, Dong-Hyun;Kim, Kyung-Min;Rhee, Dong-Ho;Cho, Hyung-Hee
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.459-466
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    • 2005
  • The present study investigates the heat transfer characteristics of a triangular channel. Three different rib configurations are tested. The ribs are installed on two sides of the channel. The rib height (e) to channel hydraulic diameter is 0.079 and the rib-to-rib pitch (p) is 8 times of the rib height. The rotation number ranges from 0.0 to 0.1 while the Reynolds number is fixed at 10,000. The copper blocks with heaters are installed on the channel walls to measure the regionally averaged heat transfer coefficients. For the stationary $45^{\circ}$ and $135^{\circ}$ ribbed channels, a pair of counter rotating vortices is induced by the angled rib arrangements, and high heat transfer coefficients are obtained on the regions near the inner wall for the $45^{\circ}$ ribbed channel and near the leading edge for the $90^{\circ}$ ribbed channel. The heat transfer coefficients of angled ribbed channels are changed little with rotation, whereas those of the transverse ribbed channel are changed significantly with rotation.

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A Targeted Counter-Forensics Method for SIFT-Based Copy-Move Forgery Detection (SIFT 기반 카피-무브 위조 검출에 대한 타켓 카운터-포렌식 기법)

  • Doyoddorj, Munkhbaatar;Rhee, Kyung-Hyune
    • KIPS Transactions on Computer and Communication Systems
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    • v.3 no.5
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    • pp.163-172
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    • 2014
  • The Scale Invariant Feature Transform (SIFT) has been widely used in a lot of applications for image feature matching. Such a transform allows us to strong matching ability, stability in rotation, and scaling with the variety of different scales. Recently, it has been made one of the most successful algorithms in the research areas of copy-move forgery detections. Though this transform is capable of identifying copy-move forgery, it does not widely address the possibility that counter-forensics operations may be designed and used to hide the evidence of image tampering. In this paper, we propose a targeted counter-forensics method for impeding SIFT-based copy-move forgery detection by applying a semantically admissible distortion in the processing tool. The proposed method allows the attacker to delude a similarity matching process and conceal the traces left by a modification of SIFT keypoints, while maintaining a high fidelity between the processed images and original ones under the semantic constraints. The efficiency of the proposed method is supported by several experiments on the test images with various parameter settings.

Preparation of Controlled Release Spheronized Beads by a Simple Extrusion and Modified Spheronization Process

  • Lee, Si-Beum;Kim, Min-Soo;Jun, Seoung-Wook;Park, Jeong-Sook;Hwang, Sung-Joo
    • Archives of Pharmacal Research
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    • v.28 no.5
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    • pp.619-625
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    • 2005
  • Beads loaded with the water-soluble drug, phenylpropanolamine HCl (PPA), were prepared using an extruder and double arm counter-rotating roller modified from a traditional pill machine. The mean diameter of the cylindrical rod-like extrudate from the ram extruder was 3 mm; that of the uncoated bead after cutting and spheronization by the modified double arm counter-rotating roller was 3.26~3.28 mm. Although the surface of the beads was moderately rough and irregular, some exhibited hump-shaped protrusions, the sphericity was acceptable (roundness 1.15) and adequate for the subsequent coating process. An increase in mean diameter of the coated beads and improvements in friability and sphericity were observed in proportion to the amount of coating material applied (ethylcellulose or Eudragit?? RS 100). It was also found that the release rate of PPA from the coated beads could be controlled by the amount and type of coating materials applied or with the incorporation of Eudragit ?? RS 100 into the core matrix. Further modifications to the double arm counter-rotating roller, including adjustment of the rotation speed and distance between the rollers, would yield smaller uncoated beads with improved roundness and surface roughness. In conclusion , the present method could be potentially applied to prepare controlled release drug delivery beads or pellet dosage forms.

A Study for the Change of Astigmatism Axis When the Fixation Point Moved Far Distance to Near Distance (원거리에서 근거리 주시 시 난시축 변화에 대한 연구)

  • Joo, Seok-Hee;Sim, Hyun-Seog
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.2
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    • pp.47-59
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    • 2007
  • When the fixation point moved far distance to near distance, the change of astigmatism type in total astigmatism showed no-changed eyes: 1,020 eyes (63.8%), changed eyes: 578 eyes(36.1 %). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into with-the-rule, against-the-rule into oblique-astigmatism of change was plenty the most respectively. In corneal astigmatism was no-changed eyes: 1,164 eyes (72.8%), changed eyes: 434 eyes(27.1%). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into with-the-rule, against-the-rule into with-the-rule astigmatism was plenty the most respectively. In residual astigmatism is no-changed eyes: 935 eyes(58.5%), changed eyes: 663 eyes(41.4%). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into against-the-rule, against-the-rule into oblique-astigmatism was plenty the most respectively. When the fixation point moved far distance to near distance, the change of astigmatism axis in total astigmatism was no-changed eyes: 761 eyes(48.5%), cyclotorsioned eyes the above 10 degrees: 837 eyes(52.3%). In corneal astigmatism was no-changed eyes: 846 eyes(52.9%), cyclotorsioned eyes the above 10 degrees : 752 eyes(47%). In residual astigmatism was no-changed eyes: 614 eyes(38.4%), cyclotorsioned eyes the above 10 degrees : 984 eyes(62.5%). The magnitude of cyclotorsion of astigmatism axis in total astigmatism was Counter clockwise rotation: 31 degrees, clockwise rotation: 20 degrees. In coneal astigmatism was Counter clockwise rotation: 25 degrees, clockwise rotation: 27 degrees. In residual astigmatism was Counter clockwise rotation: 33 degrees, clockwise rotation: 35 degrees.

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Theoretical axial wall angulation for rotational resistance form in an experimental-fixed partial denture

  • Bowley, John Francis;Kaye, Elizabeth Krall;Garcia, Raul Isidro
    • The Journal of Advanced Prosthodontics
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    • v.9 no.4
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    • pp.278-286
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    • 2017
  • PURPOSE. The aim of this study was to determine the influence of long base lengths of a fixed partial denture (FPD) to rotational resistance with variation of vertical wall angulation. MATERIALS AND METHODS. Trigonometric calculations were done to determine the maximum wall angle needed to resist rotational displacement of an experimental-FPD model in 2-dimensional plane. The maximum wall angle calculation determines the greatest taper that resists rotation. Two different axes of rotation were used to test this model with five vertical abutment heights of 3-, 3.5-, 4-, 4.5-, and 5-mm. The two rotational axes were located on the mesial-side of the anterior abutment and the distal-side of the posterior abutment. Rotation of the FPD around the anterior axis was counter-clockwise, Posterior-Anterior (P-A) and clockwise, Anterior-Posterior (A-P) around the distal axis in the sagittal plane. RESULTS. Low levels of vertical wall taper, ${\leq}10-degrees$, were needed to resist rotational displacement in all wall height categories; 2-to-6-degrees is generally considered ideal, with 7-to-10-degrees as favorable to the long axis of the abutment. Rotation around both axes demonstrated that two axial walls of the FPD resisted rotational displacement in each direction. In addition, uneven abutment height combinations required the lowest wall angulations to achieve resistance in this study. CONCLUSION. The vertical height and angulation of FPD abutments, two rotational axes, and the long base lengths all play a role in FPD resistance form.

Measuement of Temperature Probability Density Functions Variation in a Flame Near Fuel Nozzle of Gas Turbine Combustor Sector Rigs by CARS Thermometry (CARS 장치를 이용한 가스 터빈 연소기의 연료노즐 근처 화염 온도 분포 변화측정)

  • Park, Chul-Woung;Lee, Jong-Ho;Han, Yeoung-Min;Ko, Young-Sung;Lee, Kang-Yeop;Kim, Hyung-Mo;Lee, Soo-Yong;Yang, Soo-Seok;Lee, Dae-Sung;Jeon, Chung-Hwan;Chang, Young-June;Shin, Hyun-Dong;Hahn, Jae-Won
    • Journal of the Korean Society of Combustion
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    • v.7 no.2
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    • pp.7-14
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    • 2002
  • The probability density functions (PDF) of temperature were measured by coherent anti-Stokes Raman Spectroscopy (CARS) in flames of gas turbine combustor sector rig of an aero-engine. The combustor was operated at simulated ground idle conditions with standard kerosene fuel. Temperature PDFs had been measured near fuel nozzle with change of rotation of a swirler and existence of a prefilmer. The characteristic features of temperature PDFs showed the variation of combustion configurations at four experimental conditions. Without a prefilmer, large recirculation of high temperature gas was expected in the co-flow condition and un vaporized fuel fragments were detected in the counter-flow condition. With a prefilmer, the enhanced mixing increased combustion intensity near fuel nozzle in the counter-flow condition and the flame was attached far from the fuel nozzle in the co-flow condition.

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