• Title/Summary/Keyword: 3D alignment

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Dimensional Characteristics of Hydraulic Actuator Curve based on 3D Printing Filament Materials (3D 프린팅 필라멘트 재료에 따른 유압액츄에이터 커브의 치수 특성)

  • Jung, Myung-Hwi;Kong, Jeong-Ri;Kim, Hae-Ji
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.1
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    • pp.74-79
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    • 2021
  • In this paper, the 3D shape of a hydraulic actuator cover was 3D printed by applying two materials, namely PLA and ABS. Subsequently, the printed shape was scanned to analyze the material properties, dimensional change characteristics, dimensions, and scan shape as a real model. To compare and analyze material-specific 3D printing dimensions, a non-contact mobile laser scanner was used to scan a portion of the printed hydraulic actuator cover and the final alignment shape of the 3D printed part was studied on the basis of the design model.

Alignment between National College Entrance Examinations and Mathematics Curriculum Standards: A Comparative Analysis

  • Hong, Dae S.;Bae, Yejun;Wu, Yu-Fen
    • Research in Mathematical Education
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    • v.22 no.3
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    • pp.153-174
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    • 2019
  • Measuring alignment of various educational components is an important issue in educational research because with aligned educational system, we can have clear expectations about what to teach and assess. In this study, we examined the alignment between mathematics curriculum standards and college entrance examinations from Korea and China. The results indicate that curriculum standards and high stakes assessments from both countries are not well aligned to each other. Their Surveys of Enacted Curriculum (SEC) indices were lower than what previous studies have found and the critical values (Fulmer, 2011; Liu & Fulmer, 2008; Liu et al., 2009). There are several topics that are not assessed in both countries' national assessments. Also, discrepancies between the most frequently covered topics in the curriculum standards and the most frequently assessed mathematical topics in the national assessments caused topic level misalignment. We also found misalignment in cognitive level. Both national assessments included more perform procedures and demonstrate understanding items than their respective curriculum standards. Thus, previous findings about the inclusion of more items with higher cognitive demand in assessments is only partially true for either country. With these results, it is difficult to say that whether mathematical topics in the curriculum standards appropriately represent and support students to do well on the CSAT and the NCEE or that the mathematical items in the CSAT and the NCEE validly assess students' level of mathematical understanding.

Correlation Analysis between Plantar Pressure and Body Alignment According to the Dominant Hand of Elementary School Baseball Players (초등학교 야구선수들의 우세손에 따른 족저압과 신체 정렬간의 상관관계 분석)

  • Jeong, Mo-Beom
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.3
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    • pp.115-121
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    • 2021
  • PURPOSE: This study analyzed the correlation between the plantar pressure and body alignment according to the dominant hand of elementary school baseball players. METHODS: The subjects consisted of 32 elementary school baseball players. The 32 players were classified in the right-hand dominant group (Rt. Group, n = 22) and left-hand dominant group (Lt. group, n = 10). The plantar pressure was measured using a pedoscan to determine the maximum pressure and pressure distribution. The body alignment was measured using a fometric 4D to measure the trunk imbalance angle (TI), pelvic tilt angle (PTi), pelvic torsion angle (PTo), pelvis rotation angle (PR), kyphotic angle (Ky), lordotic angle (Lo), and trunk torsion angle (TT). RESULTS: Participants showed correlations in the Rt. group, according to the left maximum pressure, Lo (r = .592, p < .05), and TT (r = .514, p < .05); according to the right maximum pressure, PR (r = .539, p < .05), and Lo (r = .503, p < .05). In the left pressure distribution, the PR (r = -.521, p < .05) showed a negative correlation. In the Lt. group, the PT (r = -.591, p < .05) showed a negative correlation in the left pressure distribution. CONCLUSION: These results can be used as basic data for a body analysis study of elementary school baseball players in the future.

Analysis of Cross Sectional Ease Values for Fit Analysis from 3D Body Scan Data Taken in Working Positions

  • Nam, Jin-Hee;Branson, Donna H.;Ashdown, Susan P.;Cao, Huantian;Carnrite, Erica
    • International Journal of Human Ecology
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    • v.12 no.1
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    • pp.87-99
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    • 2011
  • Purpose- The purpose of this study was to compare the fit of two prototype liquid cooled vests using a 3D body scanner and accompanying software. The objectives of this study were to obtain quantitative measurements of ease values, and to use these data to evaluate the fit of two cooling vests in active positions and to develop methodological protocol to resolve alignment issues between the scans using software designed for the alignment of 3D objects. Design/methodology/approach- Garment treatments and body positions were two independent variables with three levels each. Quantitative dataset were dependent variables, and were manipulated in 3x3 factorial designs with repeated measures. Scan images from eight subjects were used and ease values were obtained to compare the fit. Two different types of analyses were conducted in order to compare the fit using t-test; those were radial mean distance value analysis and radial distance distribution rate analysis. Findings- Overall prototype II achieved a closer fit than prototype I with both analyses. These were consistent results with findings from a previous study that used a different approach for evaluation. Research limitations/implications- The main findings can be used as practical feedback for prototype modification/selection in the design process, making use of 3D body scanner as an evaluation tool. Originality/value- Methodological protocols that were devised to eliminate potential sources of errors can contribute to application of data from 3D body scanners.

Process Variation on Arch-structured Gate Stacked Array 3-D NAND Flash Memory

  • Baek, Myung-Hyun;Kim, Do-Bin;Kim, Seunghyun;Lee, Sang-Ho;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.2
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    • pp.260-264
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    • 2017
  • Process variation effect on arch-structured gate stacked array (GSTAR) 3-D NAND flash is investigated. In case of arch-structured GSTAR, a shape of the arch channel is depending on an alignment of photo-lithography. Channel width fluctuates according to the channel hole alignment. When a shape of channel exceeds semicircle, channel width becomes longer, increasing drain current. However, electric field concentration on tunnel oxide decreases because less electric flux converges into a larger surface of tunnel oxide. Therefore, program efficiency is dependent on the process variation. Meanwhile, a radius of channel holes near the bottom side become smaller due to an etch slope. It also affects program efficiency as well as channel width. Larger hole radius has an advantage of higher drain current, but causes degradation of program speed.

Development of 3-Dimensional Sight Distance Model for Highway Alignments (3차원 입체선형을 고려한 도로시거산정모형 개발에 관한 연구)

  • Park, Je-Jin;Choi, Joo-Yong;Ha, Tae-Jun
    • International Journal of Highway Engineering
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    • v.10 no.1
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    • pp.1-9
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    • 2008
  • Five bases for of highways are sight distance, vehicle stability, driver comfort, drainage and aesthetics. Among these bases, the sight distance is the most critical one in the highway alignment design. It is certain that highways and drivers' observation actions are 3-dimensional in nature. But, the highway alignment design and the sight distance analysis have been performed on 2-dimensional planes because of various constraints and complexity of calculating 3-dimensional sight distance. The purpose of this study is to derive a model for determining exact available sight distance in 3-D combined horizontal and vertical alignments. Application of the model is illustrated using numerical examples. The proposed model should be useful in quantifying the criteria for 3-D highway alignments.

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Three Dimensional Quantitative Structure-Activity Relationship on the Fungicidal Activities of New Novel 2-Alkoxyphenyl-3-phenylthioisoindoline-1-one Derivatives Using the Comparative Molecular Field Analyses (CoMFA) Methodology Based on the Different Alignment Approaches (상이한 정렬에 따른 비교 분자장 분석(CoMFA) 방법을 이용한 새로운 2-Alkoxyphenyl-3-phenylthioisoindoline-1-one 유도체들의 살균활성에 관한 3차원적인 정량적 구조와 활성과의 관계)

  • Sung, Nack-Do;Yoon, Tae-Yong;Song, Jong-Hwan;Jung, Hoon-Sung
    • Applied Biological Chemistry
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    • v.48 no.1
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    • pp.82-88
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    • 2005
  • 3D QSAR studies for the fungicidal activities against resistive phytophthora blight (RPC; 95CC7303) and sensitive phytophthora blight (Phytopthora capsici) (SPC; 95CC7105) by a series of new 2-alkoxyphenyl-3-phenylthioisoindoline-1-one derivatives (X: A=propynyl & B=2-chloropropenyl) were studied using comparative molecular field analyses (CoMFA) methodology. The CoMFA models were generated from the two different alignment, atom based fit (AF) alignment and field fit (FF) alignment. The atom based alignment exhibited a higher statistical results than that of field fit alignment. The best models, A3 and A7 using combination fields of H-bond field, standard field, LUMO and HOMO molecular orbital field as additional descriptors were selected to improve the statistic of the present CoMFA models. The statistical results of the two models showed the best predictability of the fungicidal activities based on the cross-validated value $q^2\;(r^2_{cv.}=RPC:\;0.625\;&\;SPC:\;0.834)$, non cross-validated value $(r^2_{ncv.}=RPC:\;0.894\;&\;SPC:\;0.915)$ and PRESS value (RPC: 0.105 & SPC: 0.103), respectively. Based on the findings, the predictive ability and fitness of the model for SPC was better than that of the model for RPC. The fugicidal activities exhibited a strong correlation with steric $(66.8{\sim}82.8%)$, electrostatic $(10.3{\sim}4.6%)$ and molecular orbital field (SPC: HOMO, 12.6% and RPC: LUMO, 22.9%) factors of the molecules. The novel selective character for fungicidal activity between two fungi depend on the positive charge of ortho, meta-positions on the N-phenyl ring and size of hydrophilicity of a substituents on the S-phenyl ring.

Alignment of Inertial Navigation Sensor and Aircraft Fuselage Using an optical 3D Coordinate Measuring Device (광학식 3차원 좌표측정장치를 이용한 관성항법센서와 기체의 정렬기법)

  • Kim, Jeong-ho;Lee, Dae-woo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.1
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    • pp.41-48
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    • 2019
  • This paper deals with a method of aligning an aircraft fuselage and an inertial navigation sensor using three-dimensional coordinates obtained by an optical method. In order to verify the feasibility, we introduce the method to accurately align the coordinate system of the inertial navigation sensor and the aircraft reference coordinate system. It is verified through simulation that reflects the error level of the measuring device. In addition, optimization method based alignment algorithm is proposed for connection between optical sensor and inertial navigation sensor.

Effect of an 8-week Closed Kinetic Chain Styled Pilates Exercise on Lower Limb Alignment (8주간 닫힌 사슬형 필라테스 운동이 하지 정렬에 미치는 영향)

  • Ga Ram Jeon;Sukhoon Yoon
    • Korean Journal of Applied Biomechanics
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    • v.33 no.4
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    • pp.128-136
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    • 2023
  • Objective: The aim of this study was to investigate the effect of an 8-week closed kinetic chain typed Reformer and Chair Pilates exercise on static and dynamic lower limb alignment for healthy female adults. Method: Ten healthy young female adults without musculoskeletal injury history in last 6 months (Age: 29.3 ± 3.5 yrs., Height: 165 ± 3.4 cm, Body mass: 58.2 ± 5.4 kg) participated in this study. All participants asked to join the 8-week closed kinetic chain typed Reformer and Chair Pilates exercise, and the program was conducted for 60 minutes twice a week. Participants were asked to be measure a static Q-angle and performed free squat one week before and after the program. A 3-D motion analysis with 8 infrared cameras and 5 channels of EMG was executed in this study. The effectiveness of the training was evaluated by paired t-test, and the significance level was set at .05. Results: A significantly decreased in internal rotation angles was found at hip joint during free squat after the training. Also, significantly decreased in lateral rotation angles were found at knee and ankle joint during free squat after training. Finally, significantly decreased in muscle activations were found at adductor longus and peroneus longus during free squat after training. Conclusion: From results of our study, it is concluded that an 8-week closed kinetic chain typed Pilates exercise positively effect on lower limb alignment during dynamic movement.

Efficient 3D Model based Face Representation and Recognition Algorithmusing Pixel-to-Vertex Map (PVM)

  • Jeong, Kang-Hun;Moon, Hyeon-Joon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.1
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    • pp.228-246
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    • 2011
  • A 3D model based approach for a face representation and recognition algorithm has been investigated as a robust solution for pose and illumination variation. Since a generative 3D face model consists of a large number of vertices, a 3D model based face recognition system is generally inefficient in computation time and complexity. In this paper, we propose a novel 3D face representation algorithm based on a pixel to vertex map (PVM) to optimize the number of vertices. We explore shape and texture coefficient vectors of the 3D model by fitting it to an input face using inverse compositional image alignment (ICIA) to evaluate face recognition performance. Experimental results show that the proposed face representation and recognition algorithm is efficient in computation time while maintaining reasonable accuracy.