• 제목/요약/키워드: Distortion of the form

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여자 부정교합자의 치료전후 연조직 측모 변화에 관한 두부 방사선학적 연구 (A CEPHALOMETRIC STUDY ON THE SOFT TISSUE PROFILE CHANGES BY ORTHODONTIC TREATMENT IN FEMALE PATIENTS)

  • 박숙규;서정훈
    • 대한치과교정학회지
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    • 제21권1호
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    • pp.113-130
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    • 1991
  • This study was undertaken to investigate soft tissue profile changes by orthodontic treatment in female patients. Traditional cephalometric appraisal yields data of dubious scientific value, the soft tissue profile forms were evaluated by finite element method. The subject was divided into three groups according to Angle's classification and each group was composed of 25 female patients averaged aged 12-14 years at the start of treatment. The changes in soft tissue form were evaluated by computing the degree of distortion in each triangle after treatment compared with the triangle before treatment. The conclusions were as follows; 1. The soft tissue profile forms were evaluated by finite element method and independent evaluation of each element by local changes was possible. 2. Maximum and minimum principal strains showed marked variability depending on the particular finite element and each group and Class II, III sample was greater than Class I sample. 3. Soft tissue size changes as a result of orthodontic treatment was not related to those of shape. 4. Soft tissue changes by orthodontic treatment were variable in individual patient, and were not related to Angle's classification.

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구두디자인에 표현된 맥시멀리즘의 특성 연구 (A Study on the Traits of Maximalism Expressed in Shoes Design)

  • 권정숙
    • 한국의류산업학회지
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    • 제10권6호
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    • pp.836-847
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    • 2008
  • Maximalism in modern fashion has emerged as an anti-conception against Minimaslism which dominated the trend of 21st century. Contrary to the traits of Minimalism which are oriented to constraint and editing, Maximalism expresses human sensitivity, concern to tradition and other culture, and instinctive desire for decoration. The trend of Maximalism is reflected in various areas of fashion and shoes design, and its influence is still enlarging. This idea for designing shoes come from analyzing the related documentaries, fashion magazines and internet sites since 2005, when the maximalism was main concepts in worldwide fashion trends. The traits of Maxmalistic trend expressed in shoes are decentralizing, pluralisml, sensitivity, etc. The molding constituents, such as form, material, color, accessary decoration, have been expressed as diversified and differentiated traits of shoes design through molding modes such as exaggeration and concentration, distortion and modification, removal and mixing-up. This study takes advantage of this opportunity to grasp the diversified and colorful trend and molding traits of Maximalim expressed in shoes design, close up the molding value of shoes design, and finally enlarge the realm of aesthetic expression of shoes design.

실린더형 쌍곡면 반사체 카메라 광각영상 복원 (Reconstruction of Wide FOV Image from Hyperbolic Cylinder Mirror Camera)

  • 김순철;이수영
    • 로봇학회논문지
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    • 제10권3호
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    • pp.146-153
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    • 2015
  • In order to contain as much information as possible in a single image, a wide FOV(Field-Of-View) imaging system is required. The catadioptric imaging system with hyperbolic cylinder mirror can acquire over 180 degree horizontal FOV realtime panorama image by using a conventional camera. Because the hyperbolic cylinder mirror has a curved surface in horizontal axis, the original image acquired from the imaging system has the geometrical distortion, which requires the image processing algorithm for reconstruction. In this paper, the image reconstruction algorithms for two cases are studied: (1) to obtain an image with uniform angular resolution and (2) to obtain horizontally rectilinear image. The image acquisition model of the hyperbolic cylinder mirror imaging system is analyzed by the geometrical optics and the image reconstruction algorithms are proposed based on the image acquisition model. To show the validity of the proposed algorithms, experiments are carried out and presented in this paper. The experimental results show that the reconstructed images have a uniform angular resolution and a rectilinear form in horizontal axis, which are natural to human.

Performance Analysis of NOMA-based Relaying Networks with Transceiver Hardware Impairments

  • Deng, Chao;Zhao, Xiaoya;Zhang, Di;Li, Xingwang;Li, Jingjing;Cavalcante, Charles Casimiro
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권9호
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    • pp.4295-4316
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    • 2018
  • In this paper, the performance of non-orthogonal multiple access (NOMA) dual-hop (DH) amplify-and-forward (AF) relaying networks is investigated, where Nakagami-m fading channel is considered. In order to cover more details, in our analysis, the transceiver hardware impairments at source, relay and destination nodes are comprehensively considered. To characterize the effects of hardware impairments brought in NOMA DH AF relaying networks, the analytical closed-form expressions for the exact outage probability and approximate ergodic sum rate are derived. In addition, the asymptotic analysis of the outage probability and ergodic sum rate at high signal-to-noise ratio (SNR) regime are carried out in order to further reveal the insights of the parameters for hardware impairments on the network performance. Simulation results indicate the performance of asymptotic ergodic sum rate are limited by levels of distortion noise.

Depth Map Coding Using Histogram-Based Segmentation and Depth Range Updating

  • Lin, Chunyu;Zhao, Yao;Xiao, Jimin;Tillo, Tammam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권3호
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    • pp.1121-1139
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    • 2015
  • In texture-plus-depth format, depth map compression is an important task. Different from normal texture images, depth maps have less texture information, while contain many homogeneous regions separated by sharp edges. This feature will be employed to form an efficient depth map coding scheme in this paper. Firstly, the histogram of the depth map will be analyzed to find an appropriate threshold that segments the depth map into the foreground and background regions, allowing the edge between these two kinds of regions to be obtained. Secondly, the two regions will be encoded through rate distortion optimization with a shape adaptive wavelet transform, while the edges are lossless encoded with JBIG2. Finally, a depth-updating algorithm based on the threshold and the depth range is applied to enhance the quality of the decoded depth maps. Experimental results demonstrate the effective performance on both the depth map quality and the synthesized view quality.

An independent distortional analysis method of thin-walled multicell box girders

  • Park, Nam-Hoi;Kang, Young-Jong;Kim, Hee-Joong
    • Structural Engineering and Mechanics
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    • 제21권3호
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    • pp.275-293
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    • 2005
  • When a thin-walled multicell box girder is subjected to an eccentric load, the distortion becomes an important global response in addition to flexure and torsion. The three global responses appear in a combined form when a conventional shell element is used thus it is not an easy task to examine the three global responses separately. This study is to propose an analysis method using conventional shell element in which the three global responses can be separately decomposed. The force decomposition method which was designed for a single-cell box girder by Nakai and Yoo is expanded herein to multicell box girders. The eccentric load is decomposed in the expanded method into flexural, torsional, and multimode distortional forces by using the force equilibrium. From the force decomposition, the combined global responses of multicell box girders can be resolved into separate responses and the distortional response which is of primary concern herein can be obtained separately. It is shown from a series of extensive comparative studies using three box girder bridge models that the expanded method produces accurate decomposed results. Noting that the separate consideration of individual global response is of paramount importance for optimized multicell box girder design, it can be said that the proposed expanded method is extremely useful for practicing engineers.

아나모르포즈(anamorphose)지각현상에 의한 공간 표현 연구 (A Study on the Expression by Anamorphose Phenomenon)

  • 이정윤;김개천
    • 한국실내디자인학회논문집
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    • 제23권4호
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    • pp.63-71
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    • 2014
  • Anamorphosis is highly favored in modern days as the atmosphere of pursuing unusual manners is growing while transformation and distortion of images are freely available. This research is to understand the affect of these distorted images on space designs and the close connection between anamorphosis and visual perceptions, and to identify the new perceptual phenomenon created through it, and the methods of expressing those. Four expressional methods were defined through the process of studying Anamorphosis based on its definition by Niceron, examining artworks such as paintings and photographs, and case-studying example spaces of visual perception experiments. Expressing anamorphosis through visual perceptions are broadly categorized to directional, dimensional, flatness, and optical. The analysis of 10 case projects suggests that the experimental spaces offer joys of finding and interpreting metaphorical forms and meanings caused by the four characteristic categories above. Also, they artificially show the boundaries between reality and virtual spaces in 2-dimensional or 3-dimensional spaces, and form hyper-boundaries, new experience, and an internal mechanism that is vague and chaotic. Therefore, this research concludes that anamorphosis which is a distorted perspective, is not only a simple measure to overcome perspectival errors, but is an existence suitable to the current era, that will extend its potential and value in spatial design.

전기자동차 충전기술 현황 및 경제적 충전 인프라 구축 (Update of charging technologies and cost-optimized charging infrastructure)

  • 하회두;박정우;김종무
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 F
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    • pp.1886-1891
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    • 1998
  • Traction battery chargers are an integral part of the required charging infrastructure. EV charging systems are continuing to improve in design. The newer types are affecting power quality to a much lesser extent. High efficiency battery chargers are being designed and produced which form little or no harmonic distortion. In addition chargers are becoming smaller and lighter. This is due mainly to the fact that there are improvements in the power electronics industry, especially with respected to IGBTs. Lower costs are achieved by the reduction in price of the IGBTs, standard magnetic material and small cores for inductors and transformers. But electric vehicles occupy a relatively small market niche at present. Therefore with already existing power supply networks, establishment of EV infrastructure can safeguard the service value of present vehicle as well as ensure the ability to charge a significant number of such vehicle. In this paper, we surveyed the update charging technologies according to the conductive charging, inductive charging and fast charging. Then we suggested cost-optimized charging infrastructure in consideration of the economical, political and technical standpoint.

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대용량 연료전지시스템의 계통외란 방지알고리즘에 관한 연구 (A Study on the Countermeasure Algorithm for Power System Disturbances in Large Scale Fuel Cell Generation System)

  • 최성식;김병기;박재범;노대석
    • 전기학회논문지
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    • 제65권5호
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    • pp.711-717
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    • 2016
  • Recently, fuel cell generation system with high energy efficiency and low CO2 emission is energetically interconnected with distribution power system. Especially, MCFC(molten carbonate fuel cell) operating at high temperature conditions is commercialized and installed as a form of large scale power generation system. However, it is reported that power system disturbances such as harmonic distortion, surge phenomenon, unbalance current, EMI(Electromagnetic Interference), EMC (Electromagnetic Compatibility) and so on, have caused several problems including malfunction of protection device and damage of control devices in the large scale FCGS(Fuel Cell Generation System). Under these circumstances, this paper proposes countermeasure algorithms to prevent power system disturbances based on the modelling of PSCAD/EMTDC and P-SIM software. From the simulation results, it is confirmed that proposed algorithms are useful method for the stable operation of a large scale FCGS.

초대형 부유식 해상공항의 파도에 의한 진동응답특성 해석 (Analysis of wave induced vibration of a typical very large floating-type offshore airport platform)

  • 이현엽;전영기;신현경
    • 한국해양공학회지
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    • 제10권4호
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    • pp.10-16
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    • 1996
  • The vibration due to progressive ocean waves is analyzed for a typical footing-type offshore airport platform. The platform is modelled as a spring-supported Euler beam and buoyancy change due to wave is considered as excitation force, under the assumption that the wave propagates without distortion by the structure. The results show that the natural frequencies of this structure are distributed very closely and are little affected by boundary conditions and that the response charateristics due to ocean waves are quite different according to the wave frequency. In this study, the wave frequencies are divided into three regions; the resonance region at which the response is governed by the resonance between the natural mode at the wave frequency and the corresponding modal component of the wave excitation force, the bending governed region at which the response is governed by the bending stiffness, and the spring (buoyancy) governed region at which the response is governed by the spring constant ahd therefore is same as the incident wave form.

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