• Title/Summary/Keyword: final positions

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Enumeration of axial rotation

  • Yoon, Yong-San
    • Advances in biomechanics and applications
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    • v.1 no.2
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    • pp.85-93
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    • 2014
  • In this paper, two procedures of enumerating the axial rotation are proposed using the unit sphere of the spherical rotation coordinate system specifying 3D rotation. If the trajectory of the movement is known, the integration of the axial component of the angular velocity plus the geometric effect equal to the enclosed area subtended by the geodesic path on the surface of the unit sphere. If the postures of the initial and final positions are known, the axial rotation is determined by the angular difference from the parallel transport along the geodesic path. The path dependency of the axial rotation of the three dimensional rigid body motion is due to the geometric effect corresponding to the closed loop discontinuity. Firstly, the closed loop discontinuity is examined for the infinitesimal region. The general closed loop discontinuity can be evaluated by the summation of those discontinuities of the infinitesimal regions forming the whole loop. This general loop discontinuity is equal to the surface area enclosed by the closed loop on the surface of the unit sphere. Using this quantification of the closed loop discontinuity of the axial rotation, the geometric effect is determined in enumerating the axial rotation. As an example, the axial rotation of the arm by the Codman's movement is evaluated, which other methods of enumerating the axial rotations failed.

Process Development of Gas Injection Molding Using Computer Aided Engineering (컴퓨터지원 공학(CAE)을 이용한 기체 사출 성형의 공정 개선)

  • 장우진;조정환;심상은;김건중;정성택;최순자
    • Polymer(Korea)
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    • v.28 no.3
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    • pp.263-272
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    • 2004
  • Using computer simulation, the processibility and properties of the inst겨ment panel of automobile produced by gas injection molding were predicted and evaluated. The P-V-T data of ABS, resin were used in the gas injection molding process in order to estimate the mold filling phenomena. The optimum process conditions were found by adjusting the process parameters including pressure, filling time, the positions of gas channel and runner. The process was simplified and the final instrument panel produced by the gas injection molding was found to have improved dimension stability compared to the one produced by conventional injection molding.

The Impact of Organizational Climate on Organizational Reputation - The Mediating Role of Organizational Health: An Empirical Study from Jordan

  • AL HARAISA, Yazan Emnawer;AL-HARAIZAH, Ahed
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.10
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    • pp.29-35
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    • 2021
  • The current study's objective isto determine the impact of organizational climate on organizational reputation in the context of organizational health as a mediating variable, in a case study of textile enterprises in Jordan that are listed on the Industrial Qualified zones. The study population contains (12) companies, according to the industrial qualified zones, with 317 employees who are working at CEO, deputy CEO, and supervisor positions chosen through convenience sampling. While the final sample of the current study consists of 174. Furthermore, to test the current study's hypotheses, the Smart Partial Least Square (PLS) technique was applied. Additionally, the current study concludes that there is a positive impact of organizational climate on organizational reputation. The current study shows that organizational climate has a positive impact on organizational health and organizational health has a positive impact on organizational reputation. Moreover, there is the mediation impact of organizational health on the relationship between organizational climate and organizational reputation. Based on the results of the current study, the study proposes that the level of organizational climate, organizational health, and organizational reputation in the examined companies be enhanced and increased.

An Efficient Positioning Method for Multi-GNSS with Multi-SBAS

  • Park, Kwi Woo;Cho, MinGyou;Park, Chansik
    • Journal of Positioning, Navigation, and Timing
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    • v.7 no.4
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    • pp.245-253
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    • 2018
  • The current SBAS service does not provide a method to integrate multiple SBAS corrections. This paper proposes a positioning method to effectively integrate multiple SBAS and multiple GNSS. In the method, the final position is obtained by the weighted sum of the positions obtained from the combination of GNSS and SBAS. Since each position is independently computed and combined using flexible weights, it has a simple structure that can easily cope with various environments. In order to verify the operation and performance of the proposed method, raw measurements of GNSS and SBAS were collected using commercial receivers. The experiments using real signals show that the combined use of two SBAS corrections was more accurate by 0.05~0.4m(2dRMS) than using only one SBAS correction. To improve the position accuracy, this paper considered the integration of multi-GNSS and multi-SBAS, which was not found in other existing studies. The proposed method is expected to be a core technology for designing multi-GNSS navigation receivers considering multi-SBAS corrections. The importance of the method will be increased as KPS and KASS also available in near future.

Development of a transfer learning based detection system for burr image of injection molded products (전이학습 기반 사출 성형품 burr 이미지 검출 시스템 개발)

  • Yang, Dong-Cheol;Kim, Jong-Sun
    • Design & Manufacturing
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    • v.15 no.3
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    • pp.1-6
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    • 2021
  • An artificial neural network model based on a deep learning algorithm is known to be more accurate than humans in image classification, but there is still a limit in the sense that there needs to be a lot of training data that can be called big data. Therefore, various techniques are being studied to build an artificial neural network model with high precision, even with small data. The transfer learning technique is assessed as an excellent alternative. As a result, the purpose of this study is to develop an artificial neural network system that can classify burr images of light guide plate products with 99% accuracy using transfer learning technique. Specifically, for the light guide plate product, 150 images of the normal product and the burr were taken at various angles, heights, positions, etc., respectively. Then, after the preprocessing of images such as thresholding and image augmentation, for a total of 3,300 images were generated. 2,970 images were separated for training, while the remaining 330 images were separated for model accuracy testing. For the transfer learning, a base model was developed using the NASNet-Large model that pre-trained 14 million ImageNet data. According to the final model accuracy test, the 99% accuracy in the image classification for training and test images was confirmed. Consequently, based on the results of this study, it is expected to help develop an integrated AI production management system by training not only the burr but also various defective images.

The acquisition of boundary tones in spontaneous speech by Korean learners of English

  • Choe, Wook Kyung
    • Phonetics and Speech Sciences
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    • v.12 no.4
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    • pp.47-55
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    • 2020
  • The current study was designed to investigate which type of phrase boundary tones high-intermediate Korean learners of English used in their spontaneous speech. These boundary tones were compared to those used in native speakers' spontaneous speech to examine whether the learners successfully acquired the use of boundary tones. To achieve this purpose, 10 Korean learners of English and four native speakers of English participated in the current study. The participants were asked to summarize the stories of short videos, and the tonal and the phrasing patterns of the obtained spontaneous speech were analyzed using Tone and Break Indices (ToBI) transcription conventions. The results indicated that both the native speakers and the Korean learners frequently marked their intonational phrase boundaries with high boundary tones. However, regarding the prosodic phrase positions within a sentence, Korean learners frequently used steep rising tones (i.e., H-H%) while native speakers used gradual rising tones (i.e., L-H%) for sentence-final intonational phrases. Overall, the findings suggested that high-intermediate Korean learners understood the forward-looking function of the high boundary tones and that they were able to make use of these tones to mark intonational phrases in their spontaneous speech.

Study on failure mechanism of line contact structures of nuclear graphite

  • Jia, Shigang;Yi, Yanan;Wang, Lu;Liu, Guangyan;Ma, Qinwei;Sun, Libin;Shi, Li;Ma, Shaopeng
    • Nuclear Engineering and Technology
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    • v.54 no.8
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    • pp.2989-2998
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    • 2022
  • Line contact structures, such as the contact between graphite brick and graphite tenon, widely exist in high-temperature gas-cooled reactors. Due to the stress concentration effect, the line contact area is one of the dangerous positions prone to failure in the nuclear reactor core. In this paper, the failure mechanism of line contact structures composed of IG11 nuclear graphite column and brick were investigated by means of experiment and finite element simulation. It was found that the failure process mainly includes three stages: firstly, the damage accumulation in nuclear graphite material led to the characteristic yielding of the line contact structure, but no macroscopic failure can be observed at this stage; secondly, the stresses near the contact area met Mohr failure criterion, and a crack initiated and propagated laterally in the contact zone, that is, local macroscopic failure occurred at this stage; finally, a second crack initiated in the contact area and developed in to a Y-shape, resulting in the final failure of the structure. This study lays a foundation for the structural design and safety assessment of high-temperature gas-cooled reactors.

Thermal Flow Analysis of an Engine Room using a Porous Media Model for Imitating Flow Rate Reduction at Outlet of Industrial Machines (다공성 매질 모델 기반 출구유량 감소 모사 기법을 이용한 산업기계용 엔진룸 열유동해석)

  • Choi, Yo Han;Yoo, Il Hoon;Lee, Chul-Hee
    • Journal of Drive and Control
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    • v.19 no.1
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    • pp.62-68
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    • 2022
  • Considering the characteristics of industrial machines that lack vehicle-induced wind, forced convection by a cooling fan is mostly required. Therefore, numerical analysis of an engine room is usually performed to examine the cooling performance in the room. However, most engine rooms consist of a number of parts and components at specific positions, leading to high costs for numerical modeling and simulation. In this paper, a new methodology for three-dimensional computer-assisted design simplification was proposed, especially for the pile of components and parts at the engine room outlet. A porous media model and regression analysis were used to derive a meta-model for imitating the flow rate reduction at the outlet by the pile. The results showed that the fitted model was reasonable considering the coefficient of determination. The final numerical model of the engine room was then used to simulate the velocity distribution by changing the mass flow rate at the outlet. The results showed that both velocity distributions were significantly changed in each case and the meta-model was valid in imitating the flow rate reduction by some piles of components and parts.

Particle-Structure Collision Modeling for Topology Optimization (위상최적설계를 위한 입자-구조 충돌 모델)

  • Young Hun Choi;Gil Ho Yoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.6
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    • pp.365-370
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    • 2023
  • This paper presents a particle-structure collision model for topology optimization, which requires sensitivity analysis. Therefore, a new model that incorporates sensitivity analysis is needed. The proposed particle-structure collision model conducts sensitivity analysis for topology optimization. To evaluate the accuracy of the proposed model, it was applied to a simplified one-dimensional collision problem. Optimization of the final positions of particles using topology optimization through this model confirmed the suitability of the proposed approach. These results demonstrate that it is possible to consider particle-structure collision in topology optimization.

Analysis of University Unification Education Research Trends Using Text Network Analysis and Topic Modeling

  • Do-Young LEE
    • Journal of Wellbeing Management and Applied Psychology
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    • v.6 no.4
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    • pp.27-31
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    • 2023
  • Purpose: This study analyzed papers identified by entering the two keywords 'unification education' and 'university' during research from 2013 to 2022 in order to identify trends and key concepts in unification education research at domestic universities. Research design, data, and methodology: The study analyzed 224 papers, excluding those on primary, middle, and high school unification education, as well as unrelated and duplicate papers. The analysis included developing a co-occurrence network of keywords, utilizing topic modeling to categorize research types, and confirming visualizations such as word clouds and sociograms. Results: In the final analysis, the research identified 1,500 keywords, with notable ones like 'Korea,' 'education,' 'unification.' Centrality analysis, measuring influence through connected keywords, revealed that 'Korea,' 'education,' 'north,' and 'unification' held significant positions. Keywords with high centrality compared to their frequency included 'learning,' 'development,' 'training,' 'peace,' and 'language,' in that order. Conclusions: This study investigated trends and structures in university-level unification education by analyzing papers identified with the keywords 'unification education' and 'university.' The use of keyword network analysis aimed to elucidate patterns and structures in university-level unification education. The significance of the study lies in offering foundational data for future research directions in the field of unification education at universities.