• Title/Summary/Keyword: positions

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Analytical vibration of FG cylindrical shell with ring support based on various configurations

  • Hussain, Muzamal;Selmi, Abdellatif
    • Advances in concrete construction
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    • v.9 no.6
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    • pp.557-568
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    • 2020
  • In this study, the impact of ring supports around the shell circumferential has been examined for their various positions along the shell axial length using Rayleigh-Ritz formulation. These shells are stiffened by rings in the tangential direction. For isotropic materials, the physical properties are same everywhere where the laminated and functionally graded materials, they vary from point to point. Here the shell material has been taken as functionally graded material. The influence of the ring supports is investigated at various positions. These variations have been plotted against the locations of ring supports for three values of length-to-diameter ratios. Effect of ring supports with middle layer thickness is presented using the Rayleigh-Ritz procedure with three different conditions. The influence of the positions of ring supports for clamped-clamped is more visible than simply supported and clamped-free end conditions. The frequency first increases and gain maximum value in the midway of the shell length and then lowers down. The Lagrangian functional is created by adding the energy expressions for the shell and rings. The axial modal deformations are approximated by making use of the beam functions. The comparisons of frequencies have been made for efficiency and robustness for the present numerical procedure. Throughout the computation, it is observed that the frequency behavior for the boundary conditions follow as; clamped-clamped, simply supported-simply supported frequency curves are higher than that of clamped-simply curves. To generate the fundamental natural frequencies and for better accuracy and effectiveness, the computer software MATLAB is used.

Compression of 3D Mesh Geometry and Vertex Attributes for Mobile Graphics

  • Lee, Jong-Seok;Choe, Sung-Yul;Lee, Seung-Yong
    • Journal of Computing Science and Engineering
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    • v.4 no.3
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    • pp.207-224
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    • 2010
  • This paper presents a compression scheme for mesh geometry, which is suitable for mobile graphics. The main focus is to enable real-time decoding of compressed vertex positions while providing reasonable compression ratios. Our scheme is based on local quantization of vertex positions with mesh partitioning. To prevent visual seams along the partitioning boundaries, we constrain the locally quantized cells of all mesh partitions to have the same size and aligned local axes. We propose a mesh partitioning algorithm to minimize the size of locally quantized cells, which relates to the distortion of a restored mesh. Vertex coordinates are stored in main memory and transmitted to graphics hardware for rendering in the quantized form, saving memory space and system bus bandwidth. Decoding operation is combined with model geometry transformation, and the only overhead to restore vertex positions is one matrix multiplication for each mesh partition. In our experiments, a 32-bit floating point vertex coordinate is quantized into an 8-bit integer, which is the smallest data size supported in a mobile graphics library. With this setting, the distortions of the restored meshes are comparable to 11-bit global quantization of vertex coordinates. We also apply the proposed approach to compression of vertex attributes, such as vertex normals and texture coordinates, and show that gains similar to vertex geometry can be obtained through local quantization with mesh partitioning.

Role of cysteine at positions 67, 161 and 241 of a Bacillus sphaericus binary toxin BinB

  • Boonyos, Patcharaporn;Soonsanga, Sumarin;Boonserm, Panadda;Promdonkoy, Boonhiang
    • BMB Reports
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    • v.43 no.1
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    • pp.23-28
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    • 2010
  • Binary toxin consisting of BinA and BinB from Bacillus sphaericus is toxic to mosquito larvae. BinB is responsible for specific binding to the larval gut cell membrane while BinA is crucial for toxicity. To investigate functional role of cysteine in BinB, three cysteine residues at positions 67, 161, and 241 were replaced by alanine or serine. Mutations at these positions did not affect protein production and overall structure of BinB. These cysteine residues are not involved in disulfide bond formation between BinB molecules. Mosquito-larvicidal assays revealed that C67 and C161 are essential for toxicity, whereas C241 is not. Mutations at C67 and C161 resulted in weaker BinA-BinB interaction. The loss of toxicity may be due to the reduction of interactions between BinA and BinB or BinB and its receptor. C67 and C161 could also play a part during conformational changes or internalization of the binary toxin into the target cell.

Microstructure and Mechanical Properties of Cu-Ni-Si Alloy Deformed by Differential Speed Rolling (이속압연에 의해 가공된 Cu-Ni-Si 합금의 미세 조직 및 기계적 성질)

  • Lee, Seong-Hee;Han, Seung Zeon
    • Korean Journal of Materials Research
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    • v.26 no.1
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    • pp.8-12
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    • 2016
  • Effects of conventional rolling(CR) and differential speed rolling(DSR) on the microstructure and mechanical properties of Cu-Ni-Si alloy were investigated in detail. The copper alloy with thickness of 3 mm was rolled to 50 % reduction at ambient temperature without lubricant with a differential speed ratio of 2:1. The conventional rolling in which the rolling speed of upper and lower rolls is identical was performed under identical rolling conditions. The shear strain introduced by the CR showed positive values at positions of upper roll side and negative values at positions of lower roll side. However, it showed zero or positive values at all positions for the samples rolled by the DSR. The microstrucure and texture development of the as-rolled copper alloy did not show any significant difference between CR and DSR. The tensile strength of the DSR processed specimen was larger than that of the CR processed specimen. The effects of rolling methods on the microstructure and mechanical properties of the as-rolled copper alloy are discussed in terms of the shear strain.

Numerical Study on the Clocking Effect in a 1.5 Stage Axial Turbine (1.5단 축류 터빈에서의 Clocking 효과에 관한 수치적 연구)

  • Park, Jong-Il;Choi, Min-Suk;Baek, Je-Hyun
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.473-480
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    • 2005
  • Clocking effects of a stator on the performance and internal flow in an UTRC 1.5 stage axial turbine are investigated using a three-dimensional unsteady flow simulation. Six relative positions of two rows of stator are investigated by positioning the second stator being clocked in a step of 1/6 pitch. The relative efficiency benefit of about 1% is obtained depending on the clocking positions. However, internal flows have some different characteristics from that in the previous study at the best and worst efficiency positions, since be first stator wake is mixed out with the rotor wake before arriving at the leading edge of the second stator. Instead of the first stator wake, it is found that the wake interaction of the first stator and rotor has a important role on a relative efficiency variation at each clocking position. The time-averaged local efficiency along the span at the maximum efficiency is more uniform than that at the minimum efficiency. That is, the spanwise efficiency distribution at the minimum efficiency has larger values in mid-span but smaller values near the hub and casing in comparison to those at the maximum efficiency. Moreover, the difference between maximum and minimum instantaneous efficiencies during one period is found to be smaller at the maximum efficiency than at the minimum efficiency.

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Reliability of Navicular Drop Measurements in Standing and Sitting Positions

  • Park, Ji-Won;Chang, Jong-Sung;Nam, Ki-Seok
    • The Journal of Korean Physical Therapy
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    • v.22 no.6
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    • pp.29-33
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    • 2010
  • Purpose: This study was designed to investigate inter-rater and intra-rater reliability of navicular drop measurements by clinicians in sitting and standing positions. Methods: Fourteen subjects with pronated foot were recruited. Two physical therapists randomly assessed the same patients on different occasions but on the same day. Almost all patients were assessed on more than one day. The intra-rater and inter-rater reliability of navicular dropwas estimated by calculation of the intraclass correlation coefficient (ICC). Results: The intra-rater reliability of navicular drop measurements ranged from 0.93 to 0.87, the inter-rater reliability from 0.98 to 0.70 with the patient in standing and sitting positions. These results showed good reliability for calculated variables. Intra-rater and inter-rater reliability of navicular drop in standing position was higher than those of sitting position. Conclusion: Although inter-rater and intra-rater reliability of navicular drop in the sitting position was lower than in the standing position, measurement of navicular drop in the sitting position showed good reliability and was acceptable for patients who could not stand alone without assistance. We recommend that having the patient in the standing position is appropriate in navicular drop measurement.

Changes of Thickness in Abdominal Muscles between Crook Lying and Wall Support Standing during Abdominal Hollowing in Healthy Men

  • Park, Du-Jin
    • The Journal of Korean Physical Therapy
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    • v.22 no.6
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    • pp.7-12
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    • 2010
  • Purpose: This study investigated changes in the thickness of the transversus abdominis (TrA), internal abdominal oblique (IO), and external abdominal oblique (EO) muscles between crook lying and wall support standing positions during abdominal hollowing (AH), using ultrasound imaging. Methods: Experiments were conducted on 20 healthy male adults (mean age=$22.45{\pm}4.08$ years) who voluntarily agreed to participate in the experiments. The changes in the thickness of the subjects' abdominal muscles were measured during AH in crook lying and wall support standing positions. Results: The difference in the thickness of TrA between the two positions during AH was statistically significant, but the differences in the thicknesses of IO and EO were not significant. Conclusion: Activity of the TrA, which is a deep muscle, was stimulated in the standing position, which is, therefore, more functional than the crook position, but the activities of IO and EO muscles did not decrease. Therefore, various methods to induce the activity of TrA while decreasing the activities of IO and EO, in the functional standing position that can stimulate deep muscles, need to be designed.

Local and Global Information Exchange for Enhancing Object Detection and Tracking

  • Lee, Jin-Seok;Cho, Shung-Han;Oh, Seong-Jun;Hong, Sang-Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.5
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    • pp.1400-1420
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    • 2012
  • Object detection and tracking using visual sensors is a critical component of surveillance systems, which presents many challenges. This paper addresses the enhancement of object detection and tracking via the combination of multiple visual sensors. The enhancement method we introduce compensates for missed object detection based on the partial detection of objects by multiple visual sensors. When one detects an object or more visual sensors, the detected object's local positions transformed into a global object position. Local and global information exchange allows a missed local object's position to recover. However, the exchange of the information may degrade the detection and tracking performance by incorrectly recovering the local object position, which propagated by false object detection. Furthermore, local object positions corresponding to an identical object can transformed into nonequivalent global object positions because of detection uncertainty such as shadows or other artifacts. We improved the performance by preventing the propagation of false object detection. In addition, we present an evaluation method for the final global object position. The proposed method analyzed and evaluated using case studies.

Development of a Formula for Acoustic Transmission Loss According to Partition Positions in a Simple Expansion Chamber (단순확장관 내부 파티션 위치에 따른 음향투과손실 계산식의 개발)

  • Park, Jeong-Pil;Bae, Kyeong-Won;Jeong, Weui-Bong;Ahn, Se-Jin
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.25 no.2
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    • pp.116-123
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    • 2015
  • This paper proposed a new formula for predicting acoustic power transmission loss of simple expansion chamber with two internal partitions. Seventeen cases of computational results were performed and the database was constructed for the TL according to the various positions of internal partitions. Using this database, firstly, the formula for the peak values of TL at certain frequencies was developed using the least square estimation. Secondly, the formula for the TL curve could be obtained automatically with the input data of the positions of two internal partitions. The formula of TL developed in this paper showed good agreement with computational results. This formula will be helpful for the positioning of internal partitions to improve TL at target frequencies.

A study on the development of gas measurement system in shoes mold and automatic gas-vent exchange machine with computer vision (신발금형의 가스 배출량 측정 장치와 영상정보를 이용한 가스벤트 자동 교환 시스템의 개발)

  • Kwon, Jang-Woo;Hong, Jun-Eui;Yoon, Dong-Eop;Choi, Heung-Ho;Kil, Gyung-Suk
    • Journal of Sensor Science and Technology
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    • v.15 no.1
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    • pp.20-27
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    • 2006
  • This paper presents a gas measurement system for deciding hole positions on a PU middle-sole mold from computed gas amount. The optimal number of holes and their positions on the shoe mold are decided from statistical experiment results to overcome the problem of excessive expenses in gas vent exchange. This paper also describes a gas vent exchange mechanism using computer vision system. The gas hole detecting process is based on computer vision algorithms represented as a simple Pattern Matching. The experimental result showed us that the system was useful to calculate the number of holes and their positions on the shoes mold.