• Title/Summary/Keyword: Three-Dimension

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패러렐 카메라모델을 이용한 3차원 스캐너 시스템 (Three Dimension Scanner System Using Parallel Camera Model)

  • 이희만
    • 전자공학회논문지CI
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    • 제38권2호
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    • pp.27-32
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    • 2001
  • 본 논문은 패러렐 카메라 모델을 사용한 카메라 캘리브레이션과 3차원 스캐닝 알고리즘에 관한 것이다. 레이저 스트립라인이 스테레오 매칭을 위해 보조적으로 사용하였으나 원리적으로는 불필요하다. 피측정 물체는 스뎀핑모터에 의해 플레이트 위에서 360도 회전하며, 카메라로부터 거리를 측정하여 월드좌표를 구한다. 피측정 물체의 월드좌표는 모델좌표로 변환되며 다수의 군집 모델좌표로부터 모델링을 위한 면을 추출하고 OpenGL을 이용하여 렌더링 한다. 본 알고리즘은 에피폴라 라인의 매칭점의 유효성을 검사하여 잘못된 매칭값을 버리고 무효한 매칭값은 유효한 값으로부터 보간법으로 산출한다.

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자동차 엔진음의 청각 감성 평가 척도 개발 (Development of Auditory Evaluation Scale in Automobile Engine Sound)

  • 김원준
    • 품질경영학회지
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    • 제48권3호
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    • pp.409-420
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    • 2020
  • Purpose: The purpose of this study is to develop a measurement scale for evaluating the auditory affect of automobile engine sounds. Methods: In order to collect affective vocabulary, literature review, user tests, and expert interviews were conducted. Affective vocabulary related to automobile engine sounds was selected through three methods. To develop the evaluation scale, open/close card-sorting and expert interview-based survey method was used. Results: The results of this study are as follows; In order to select the main affective vocabulary from the collected vocabulary, 39 vocabularies with a frequency of 5 or higher were selected as vocabulary expressing the main auditory affect of automobile engine sounds. Each affective vocabulary is divided into three di- mensions, it was confirmed that the conceptual model for the auditory affect of automobile engine sounds is composed of three levels: intuitive, descriptive, and evaluative of hierarchical structure. As a result of the study, four indices of intuitive dimension, seven indices of descriptive dimension, and one index of evaluative dimension were derived from the evaluation scale of the auditory affect in an automobile engine sound. Conclusion: The auditory evaluation scale developed in this study can be used to systematically measure and evaluate the auditory affect of automobile engine sounds.

계단규격에 대한 생리학적 평가 (A physiological assessment of stair dimensions)

  • 명노해;이순요;김형범
    • 대한인간공학회:학술대회논문집
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    • 대한인간공학회 1995년도 추계학술대회논문집
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    • pp.87-90
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    • 1995
  • Biomechanical can physchological approaches have provided the optimum stair dimensions but physiological approach has never been used in assessing the common method of assessing the optimum stair dimension. Therefore, this study was conducted to investigate the validity of the physiological measure of heart rate in assessing the optimum stair dimensions. Sixteen subjects were asked to walk up three different stairs with their normal walking speed. The results showed that the physiological approach with the heart rate difference was found to be valid in assessing the optimum stair dimension. The optimum stair dimension from this study (riser length for 185 mm and tread length for 310 mm) was chosen because it was similar to optimum dimension by the psychological approach (Irvine et al., 1990).

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Crack Growth Behaviors of Cement Composites by Fractal Analysis

  • Won, Jong-Pil;Kim, Sung-Ae
    • KCI Concrete Journal
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    • 제14권1호
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    • pp.30-35
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    • 2002
  • The fractal geometry is a non-Euclidean geometry which describes the naturally irregular or fragmented shapes, so that it can be applied to fracture behavior of materials to investigate the fracture process. Fractal curves have a characteristic that represents a self-similarity as an invariant based on the fractal dimension. This fractal geometry was applied to the crack growth of cementitious composites in order to correlate the fracture behavior to microstructures of cementitious composites. The purpose of this study was to find relationships between fractal dimensions and fracture energy. Fracture test was carried out in order to investigate the fracture behavior of plain and fiber reinforced cement composites. The load-CMOD curve and fracture energy of the beams were observed under the three point loading system. The crack profiles were obtained by the image processing system. Box counting method was used to determine the fractal dimension, D$_{f}$. It was known that the linear correlation exists between fractal dimension and fracture energy of the cement composites. The implications of the fractal nature for the crack growth behavior on the fracture energy, G$_{f}$ is apparent.ent.

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저가항공 관련 국내학술지 네트워크 텍스트 분석 (Bibliometric Network Analysis on Low Cost Carrier Research)

  • 나진성;최동현
    • 한국항공운항학회지
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    • 제23권1호
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    • pp.14-23
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    • 2015
  • This study applied the network text analysis to reveal the scope and trends of low cost carrier studies. We analyzed low cost carrier research published in Korean journals and news articles. The results showed that there are three clusters in terms of research topics. First dimension consists of articles investigating growth in the low cost carrier industry. The second dimension is associated with service characteristics. The last dimension has strong ties organizational and human resource dimension. We run Krkwic, Krtitle, Netdraw, and Ucinet 6.0 to conduct the network text analysis. This study suggests the direction of low cost carrier research in the future.

대동작 측정도구의 측정자간 신뢰도 (Inter-Rater Reliability of the Gross Motor Function Measure)

  • 이충휘;황선관;최흥식
    • 한국전문물리치료학회지
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    • 제2권1호
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    • pp.1-13
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    • 1995
  • The purpose of this study was to examine the inter-rater reliability of the Korean translation of the GMFM(Gross Motor Function Measure). Three licensed physical therapists with varying amounts(2 - 6 years) of clinical experience served as raters. Thirty patients with cerebral palsy were subjects for this study. Subjects were 22 boys and 8 girls, aged 1 to 8 years. Reliability of each dimension and each total score of the GMGM were analyzed using ICCs(intraclass correlation coefficients). The reliability of each dimension score ranged from .76 to .98, with the walking, running, and jumping dimension having higher reliability values. The reliability of the total dimension score was .94. We conclude that the GMFM has inter-rater reliability for assessing gross motor function in patients with cerebral palsy.

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3차원 사이버공간에 표현된 청소년의 공간의식 (Adolescents' Spatial Perception in the 3-Dimension Cyberspace)

  • 박경옥;김효영
    • 한국주거학회논문집
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    • 제17권2호
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    • pp.97-106
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    • 2006
  • The purpose of this study is to provide basic data for the planning of adolescents preferred space, and fur the purpose of the study analyzed the spaces made by them in the web site where 3-dimension space manipulating is possible and captured their consciousness of space. The study was to interview 60 adolescents in the web-site by video chatting and observation by video ethnography. The results are as follows. 1) Three-dimension space is where adolescents express their present preference for spaces of residence, leisure and outer activities, and where they reveal their desire to be realized in the future. 2) Adolescents foster friendship in the cyberspace, where they meet friends and enjoy talking and share their desire for space creation which is hardly come true in reality. 3) It is possible to grasp their latent preference of space, and actualization of the cyber preference would give them more satisfaction.

Two variations of cross-distance selection algorithm in hybrid sufficient dimension reduction

  • Jae Keun Yoo
    • Communications for Statistical Applications and Methods
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    • 제30권2호
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    • pp.179-189
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    • 2023
  • Hybrid sufficient dimension reduction (SDR) methods to a weighted mean of kernel matrices of two different SDR methods by Ye and Weiss (2003) require heavy computation and time consumption due to bootstrapping. To avoid this, Park et al. (2022) recently develop the so-called cross-distance selection (CDS) algorithm. In this paper, two variations of the original CDS algorithm are proposed depending on how well and equally the covk-SAVE is treated in the selection procedure. In one variation, which is called the larger CDS algorithm, the covk-SAVE is equally and fairly utilized with the other two candiates of SIR-SAVE and covk-DR. But, for the final selection, a random selection should be necessary. On the other hand, SIR-SAVE and covk-DR are utilized with completely ruling covk-SAVE out, which is called the smaller CDS algorithm. Numerical studies confirm that the original CDS algorithm is better than or compete quite well to the two proposed variations. A real data example is presented to compare and interpret the decisions by the three CDS algorithms in practice.

Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity

  • Shah, Farhan Khalid;Gebreel, Ashraf;Elshokouki, Ali Hamed;Habib, Ahmed Ali;Porwal, Amit
    • The Journal of Advanced Prosthodontics
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    • 제4권2호
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    • pp.61-71
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    • 2012
  • PURPOSE. To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS. Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS. Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION. Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis.