• Title/Summary/Keyword: directionality function

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The Importance of Halogen Bonding: A Tutorial

  • Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.5 no.3
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    • pp.195-197
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    • 2012
  • Halogen atoms in a molecule are traditionally considered as electron donors, since they have unshared electrons. Normally when they are bonded, there are three lone pair electrons. These lone pairs can function as Lewis bases. However, when they are bound to electron withdrawing groups, they can act as Lewis acids. Since the situation is similar hydrogen bonding (HB), this type of interaction is named as halogen bonding (XB). This mainly comes from the uneven distribution of electron density around the halogen atoms. Since the electron density around halogen atom opposite to ${\sigma}$-bond is depleted, its electropositive region is called ${\sigma}$-hole. This ${\sigma}$-hole can attract halogen bond acceptors, requiring more stringent directionality compared to HB. Since this interaction mainly comes from electrostatic origin, the geometry tends to be linear. Since the XB energy is comparable to corresponding HB. Still in its infancy, XB shows a broad range of applicability, with potentially more useful properties, compared to corresponding HB.

Determination of Hypocentral Parameters Using Phase Identification and Two-Point Ray Tracing (파형분석과 두 점을 잇는 파선추적을 이용한 지진요소 결정)

  • 박종찬;김우환
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.5
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    • pp.57-61
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    • 2001
  • This study introduces an algorithm for determination of hypocentral parameters using phase analysis and two-point ray tracing to enhance accuracy and stability of computations. When the magnitude of earthquake is relatively small(usually $m_{b}$<3.2), the PmP phase which looks like the first arrival phase may be observed without observing the Pn phase. In this case, the hypocentral parameters calculated by the existing method using the first arrival of P and S phases and by the method developed in this study using PmP and SmS phases show large differences. The computational results of determination of hypocentral parameters for actual earthquake events show that this method gives much smaller rms errors than the existing methods do.o.

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A joint probability distribution model of directional extreme wind speeds based on the t-Copula function

  • Quan, Yong;Wang, Jingcheng;Gu, Ming
    • Wind and Structures
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    • v.25 no.3
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    • pp.261-282
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    • 2017
  • The probabilistic information of directional extreme wind speeds is important for precisely estimating the design wind loads on structures. A new joint probability distribution model of directional extreme wind speeds is established based on observed wind-speed data using multivariate extreme value theory with the t-Copula function in the present study. At first, the theoretical deficiencies of the Gaussian-Copula and Gumbel-Copula models proposed by previous researchers for the joint probability distribution of directional extreme wind speeds are analysed. Then, the t-Copula model is adopted to solve this deficiency. Next, these three types of Copula models are discussed and evaluated with Spearman's rho, the parametric bootstrap test and the selection criteria based on the empirical Copula. Finally, the extreme wind speeds for a given return period are predicted by the t-Copula model with observed wind-speed records from several areas and the influence of dependence among directional extreme wind speeds on the predicted results is discussed.

A Study on the Characteristic of Raumplan based on the Architectural Thought of Adolf Loos (아돌프 로스의 건축사상에 기초한 라움플란의 특성에 관한 연구)

  • Park, Chan-Il
    • Korean Institute of Interior Design Journal
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    • v.17 no.6
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    • pp.30-40
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    • 2008
  • Adolf Loos showed important directionality in the thought of modem culture and architecture. The thought about the architecture of Adolf Loos was gathered by "Raumplan". It is the solution of the plan in space. But the concept and method of the "Raumplan" had not been synthesized until near the end of Loos's life. Loos's first reference to the "Raumplan" appears in 1929. I think that "Raumplan" became the solution of the plan in space with a formation process of the thought about the architecture and culture of Adolf Loos. Therefore, the purpose of this paper derived a characteristic of "Raumplan" from the relations between the architectural thought of Adolf Loos and "Raumplan". The processes of the study are as follows. (1)Consideration about the growth background of Adolf Loos and the social situation of Vienna. (2)Analysis about architecture and the cultural critic of Adolf Loos. (3)Analysis of "Raumplan" based on architectural thought of Adolf Loos. As a result, I got the four characteristics of "Raumplan" as follows. (1) Separation and continuation of "Raum". (2) Fragment of "Raum". (3) Overlay and transmission by the axis of multiplex eyes. (4) Structural adjustment of the "Raum" by Hierarchy. Finally, I understood the architecture which Adolf Loos pursued in "Raumplan" had a high function and contained the clear meaning and contents which had practical use and economic value, and it were not a results of the simple logic.

Multi-view Display with Hologram Screen using Three-dimensional Bragg Diffraction

  • Okamoto, Masaaki;Shimizu, Eiji
    • Journal of Information Display
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    • v.3 no.3
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    • pp.1-11
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    • 2002
  • Multi-view function is important to three-dimensional displays without dedicated glasses. It is the reason that the observers earnestly desire to change their positions freely. Multi-viewing is also principal to the reality of three-dimensional (3D) image displayed on the screen. The display of projection type has the advantage that the number of viewing points can be easily increased according to the number of projectors. The authors research on multi-view projection display with hologram screen. Powerful directionality of the diffracted beam from hologram screen is required unlike two-dimensional (2D) display. We developed a new method that all diffracted beams satisfied the same Bragg condition and became sufficiently bright to observe the 3D image under usual indoor light. The principle is based on the essential Bragg diffraction in the three-dimensional space. Owing to such three-dimensional Bragg diffraction we achieved an excellent hologram screen that could be multiple reconstructed in spite of single recording. This hologram screen is able to answer arbitrary numbers of viewing points within wide viewing zone. The distortion of 3D image becomes also sufficiently small with the method of dividing the cross angle between illumination and diffraction beam.

Modeling of ambient noise in ocean environment using coupled mode (연성모드법을 이용한 해양 배경소음 모델링)

  • Park, Jungyong;Kwon, Hyuckjong
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.4
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    • pp.397-409
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    • 2022
  • A model is developed for the calculation of sea surface generated ambient noise in the range dependent ocean environment. The sources are located in the horizontal plane all around and their depths are at the near-surface. The receiver array is located in the range dependent ocean waveguide. One-way coupled mode method is used to model the acoustic propagation between the sources and receiver in the range dependent waveguide, and the cross spectral density matrix of noise is derived. In simulation, noise intensity, beamforming result and coherence function are calculated from the cross spectral density matrix. These results are compared with those in the range independent environment. The modeling result shows the effect of the vertical directionality and asymmetry characteristics of the horizontal plane.

Hydrophobicity Evaluation of Oblique Micro-asperities Structures (경사 돌기 표면의 젖음 특성 평가)

  • Sung Ik Beak;Tae Wan Kim
    • Tribology and Lubricants
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    • v.39 no.2
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    • pp.56-60
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    • 2023
  • In this study, we evaluate the anisotropic flow of droplets according to the directionality of asperities. We manufacture a mold with an inclined hole by adjusting the jig angle using a high-power diode laser. Using the manufactured mold, we prepare specimens for wettability studies by the micro molding technique. We fabricate twelve kinds of surfaces with micro-asperities inclined at 0°, 15°, 30°, and 45° for asperity pitches of 100 ㎛, 200 ㎛, and 300 ㎛. We evaluate the static and dynamic behaviors of the droplets as a function of the asperities pitch and inclination angles. The anisotropic effect increases as the pitch increases between asperities, and the anisotropic flow characteristics increase as the inclination angle of the asperities increases. On the surface with hole pitches of 100 ㎛ and 200 ㎛, the contact angle of the droplet shows high hydrophobicity at approximately 160°, but on the surface with the 300-㎛ hole pitch, the contact angle is approximately 110°, indicating that the hydrophobic effect rapidly reduces. Additionally, when the inclination angle of the asperities is approximately 30°, the left and right contact angle deviations of the droplet are the lowest, showing that the roll-off angle is relatively low.

Implementation of GLCM/GLDV-based Texture Algorithm and Its Application to High Resolution Imagery Analysis (GLCM/GLDV 기반 Texture 알고리즘 구현과 고 해상도 영상분석 적용)

  • Lee Kiwon;Jeon So-Hee;Kwon Byung-Doo
    • Korean Journal of Remote Sensing
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    • v.21 no.2
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    • pp.121-133
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    • 2005
  • Texture imaging, which means texture image creation by co-occurrence relation, has been known as one of the useful image analysis methodologies. For this purpose, most commercial remote sensing software provides texture analysis function named GLCM (Grey Level Co-occurrence Matrix). In this study, texture-imaging program based on GLCM algorithm is newly implemented. As well, texture imaging modules for GLDV (Grey Level Difference Vector) are contained in this program. As for GLCM/GLDV Texture imaging parameters, it composed of six types of second order texture functions such as Homogeneity, Dissimilarity, Energy, Entropy, Angular Second Moment, and Contrast. As for co-occurrence directionality in GLCM/GLDV, two direction modes such as Omni-mode and Circular mode newly implemented in this program are provided with basic eight-direction mode. Omni-mode is to compute all direction to avoid directionality complexity in the practical level, and circular direction is to compute texture parameters by circular direction surrounding a target pixel in a kernel. At the second phase of this study, some case studies with artificial image and actual satellite imagery are carried out to analyze texture images in different parameters and modes by correlation matrix analysis. It is concluded that selection of texture parameters and modes is the critical issues in an application based on texture image fusion.

Actin Depolymerizing Factor Destrin Regulates Cilia Development and Function during Vertebrate Embryogenesis

  • Youni Kim;Hyun-Kyung Lee;Kyeong-Yeon Park;Tayaba Ismail;Hongchan Lee;Hyun-Shik Lee
    • Development and Reproduction
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    • v.28 no.3
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    • pp.109-119
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    • 2024
  • The actin cytoskeleton plays fundamental roles in ciliogenesis and the actin depolymerizing factor destrin regulates actin dynamics by treadmilling actin filaments and increasing globular actin pools. However, the specific developmental roles of destrin in ciliogenesis have not been fully elucidated. Here, we investigated the function of destrin in ciliogenesis using Xenopus laevis and human retinal pigmented epithelial (hRPE1) cells. We discovered the loss of destrin increased the number of multiciliated cells in the Xenopus epithelium and impeded cilia motility. Additionally, destrin depletion remarkably reduced the length of primary cilia in the Xenopus neural tube and hRPE1 cells by affecting actin dynamics. Immunofluorescence using markers of ciliary components indicated that destrin controls the directionality and polarity of basal bodies and axonemal elongation by modulating actin dynamics, independent of basal body docking. In conclusion, destrin plays a significant role during vertebrate ciliogenesis regulating both primary and multicilia development. Our data suggest new insights for understanding the roles of actin dynamics in cilia development.

Makeup transfer by applying a loss function based on facial segmentation combining edge with color information (에지와 컬러 정보를 결합한 안면 분할 기반의 손실 함수를 적용한 메이크업 변환)

  • Lim, So-hyun;Chun, Jun-chul
    • Journal of Internet Computing and Services
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    • v.23 no.4
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    • pp.35-43
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    • 2022
  • Makeup is the most common way to improve a person's appearance. However, since makeup styles are very diverse, there are many time and cost problems for an individual to apply makeup directly to himself/herself.. Accordingly, the need for makeup automation is increasing. Makeup transfer is being studied for makeup automation. Makeup transfer is a field of applying makeup style to a face image without makeup. Makeup transfer can be divided into a traditional image processing-based method and a deep learning-based method. In particular, in deep learning-based methods, many studies based on Generative Adversarial Networks have been performed. However, both methods have disadvantages in that the resulting image is unnatural, the result of makeup conversion is not clear, and it is smeared or heavily influenced by the makeup style face image. In order to express the clear boundary of makeup and to alleviate the influence of makeup style facial images, this study divides the makeup area and calculates the loss function using HoG (Histogram of Gradient). HoG is a method of extracting image features through the size and directionality of edges present in the image. Through this, we propose a makeup transfer network that performs robust learning on edges.By comparing the image generated through the proposed model with the image generated through BeautyGAN used as the base model, it was confirmed that the performance of the model proposed in this study was superior, and the method of using facial information that can be additionally presented as a future study.