• Title/Summary/Keyword: Mutual structures

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Scan Performance Analysis by Mutual Coupling Effects in Fabry-Perot Cavity Antennas (패브리 패롯 공진기형 안테나에서 뮤츄얼 커플링에 의한 스캔특성 분석)

  • Kim, Jong-Sung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.10
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    • pp.21-25
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    • 2014
  • Scan capabilities of Fabry-Perot cavity (FPC) antennas are investigated for the case of a $4{\times}1$ thinned array placed inside the cavity. The FPC array antenna has higher maximum gain and lower sidelobe level (SLL), but the maximum scan angle of the thinned array is 14-17% lower than the patch array alone, due to increased mutual coupling in the FPC structures. However, unlike the bare thinned array, the SLL of FPC array does not suffer from the grating lobe problem even though it has a relative large element spacing of more than $1.0{\lambda}_0$.

Securing Internet of Vehicles with a provable secure post-quantum mutually authenticated protocol based on Small Integer Solution

  • WenBin Hsieh
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.10
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    • pp.3040-3059
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    • 2024
  • As technology advances, vehicular ad hoc networks (VANETs) have evolved into the Internet of Vehicles (IoVs), transforming the IoT landscape. IoV integrates automotive sensor to collect data from the environment, vehicles, and drivers, using wireless links that are vulnerable to attacks. This necessitates strong security measures to protect confidential data shared between vehicles and Road Side Units (RSUs). While earlier protocols are susceptible to quantum computer-enabled attacks, Gupta et al. proposed an identity-based mutual authentication protocol to address these concerns. However, this paper identifies several flaws in Gupta et al.'s protocol and introduces an enhanced identity-based mutual authenticated key agreement protocol that leverages small integer solution (SIS) problems. The security and efficiency of the proposed quantum-resistant protocol can be further enhanced by meticulously adjusting parameters, including lattice structures, computational complexity, and elliptic curve configurations such as curve order and field size. Furthermore, we utilize BAN logic for rigorous security validation of our solution, supplemented by performance benchmarks including communication efficiency and computational overhead, in comparison to related protocols. Additionally, we present a critical design perspective for key negotiation solutions. While no protocol is flawless at inception, our proposed solution substantially improves security in the IoT domain.

High-Resolution Map of Zodiacal Dust Bands by WIZARD

  • Yang, Hongu;Ishiguro, Masateru;Usui, Fumihiko;Ueno, Munetaka
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.101.1-101.1
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    • 2012
  • Interplanetary dust particles are observable as zodiacal light, which is the sunlight scattered by the interplanetary dust particles. The origins of interplanetary dust particles are still in question because they are eroded by Poynting-Robertson photon drag and mutual collisions among dust particles. The small-scale structures in the zodiacal light provided a clue to specify their origins. Asteroidal debris were detected as band-like structures (dust bands), and the cometary large particles were detected as narrow trails (dust trails). However, little is confirmative about their detailed origins and mineralogical compositions because of the lack of observational data particularly in the optical wavelength. We made a high-resolution optical zodiacal light map based on the CCD observations at Mauna Kea, Hawaii. We analyzed data taken on November 12, 2004. After the data reduction, such as flat fielding and subtraction of airglow emissions, we succeeded in the construction of the zodiacal light map with the spatial resolution of 3' in the solar elongation between 45 degree and 180 degree. This is the highest resolution map in the visible wavelength so far. In this map, we confirmed the dust bands structures near the ecliptic plane. We will discuss about the similarities and the differences between optical and infrared dust bands.

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Analysis of Some Korean Terminologies on the Flower Structures of Angiosperms in Plant Morphology (식물형태학에서 사용하는 피자식물의 꽃 구조에 관한 한글 용어의 분석)

  • Lee, Kyu Bae
    • Journal of Integrative Natural Science
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    • v.2 no.2
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    • pp.86-100
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    • 2009
  • Korean terminologies on flower structures of angiosperms in plant morphology, written incorrectly in many books, were analysed to suggest accurately expressed terminologies. 24 books in areas such as general biology, plant biology, plant morphology, and biological dictionaries and glossaries were selected to analyse the accuracy of the terminologies for seed structures, e.g., crassinucellate (ovule), tenuinucellate (ovule), placentation, free cental placentation, herkogamy or hercogamy, heterostyly or heterostylous, distyly or distylous, tristyly or tristylous, and hypanthium. The definition and etymology of the terminologies were traced in 4 textbooks of plant anatomy and 2 dictionaries of biology and botany written in English. On the basis of the definition, etymology, and principles for terminology formation according to the International Organization for Standardization (ISO 704:2000), accurately and reasonably expressed Korean terminologies were proposed. The 9 terminologies examined in this study were found in the glossary of biological terminologies, published by the Korean Association of Biological Sciences in 2005, and designated as an editorial source for science and biology textbooks for middle and high schools by Ministry of Education in 2007. However, none of the 9 terminologies described in the glossary were consistent with those proposed in the present study. The inconsistencies indicated the need for a reassessment of this glossary of biological terminologies. The new, proposed terminologies would facilitate mutual understanding between teachers and students of plant biology.

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Study of Seismic Resistance Performance Evaluation Method for Existing Mid-Low Story RC Structure Buildings by Applying Fuzzy Theory (퍼지이론을 적용한 기존 중저층 철근콘크리트 건축물의 내진성능평가기법 연구)

  • Kim, Dong-Hee;Kim, Hyun-Su
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.2
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    • pp.53-62
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    • 2017
  • This study aims to establish a seismic resistance performance evaluation method that makes sure to secure the seismic resistance performance of the existing mid-low story reinforced concrete structures. This study focuses on the development of the seismic resistance performance evaluation method for the overall seismic resistance performance evaluation on the buildings by applying fuzzy theory. This seismic resistance performance evaluation method considers the mutual relations among the type of force, the type of member, the type of story, and the states of deterioration of the buildings. The total seismic resistance performance index from this method was calculated by the intensity weight of each evaluation item, fuzzy measure, fuzzy integration. Moreover, the evaluation methodology was established in this study to identify the performance level of the Immediate Occupancy, Life Safe, Collapse Prevention by applying the fuzzy theory.

The Evolution and Structural Characteristics of Scaffolding Constructions in Macao Area from Historical Documents and Visual Materials (문헌 및 도상(圖像) 사료를 통해 본 마카오 '붕식(棚式)' 건축의 연원(淵源)과 구조 형식)

  • Hong, Shu-ying;Han, Dong-Soo
    • Journal of architectural history
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    • v.32 no.1
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    • pp.7-20
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    • 2023
  • The construction method of scaffolding structures is different from Mortise and Tenon and bucket arch structure of traditional large woodwork. It forms an independent construction system-fixing nodes with knots, a large number of diagonal braces are used to fix shelves and the structures mostly contain X-shape and triangular shape details. Simple ones include stalls, sheds, rain sheds, altars, lamp racks etc. But the scaffolding with larger scale and more complicated structure are modeled on archways, theatres and other buildings which are used in commercial and festival activities. At present, Macao, Hong Kong, Guangdong, Sichuan, Shanxi and other places in China have retained the custom of using scaffolding structures in important festival activities, but their uses, techniques and building types are slightly different from place to place. Due to building and demolishing at any time, the construction and service cycle is short. As a result, there are almost no physical objects left. We can only deduce the use and technical characteristics of ancient scaffolding skills through the colorful building styles that have been preserved with folk activities in various parts of China, the craftsmanship handed down from generation to generation by the scaffolding guild and artisans, and the description of cultural and historical materials and the mutual corroboration of visual materials.

Interpretation of Paleostress using Geological Structures observed in the Eastern Part of the Ilgwang Fault (일광단층 동편에서 관찰되는 지질구조를 이용한 고응력사 해석)

  • Kim, Taehyung;Jeong, Su-Ho;Lee, Jinhyun;Naik, Sambit Prasanajit;Yang, Wondong;Ji, Do Hyung;Kim, Young-Seog
    • The Journal of Engineering Geology
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    • v.28 no.4
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    • pp.645-660
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    • 2018
  • In the southeastern part of the Korean Peninsula, huge fault valleys, including the Yangsan and Ulsan faults, are recognized. These NNE-SSW trending lineaments are called as a whole Yangsan Fault System. However, this fault system is relatively poorly studied except the Yangsan and Ulsan faults. This study deduced the paleostress history based on the mutual cross-cutting relationships between geologic structures developed in the granite body near the Ilgwang fault, which is compared with previous studies. In the study area, four lineaments parallel to the Ilgwang fault are recognized, and three of them show evidences of faulting. In each lineament, both slip-senses of left-lateral and right-lateral are recognized. It indicates that these faults consistently underwent multiple deformations of inversion along the faults. The inferred paleostress directions based on the mutual cross-cutting relationships of the geological structures are as follows: 1) Tensile fractures developed in the late Cretaceous under the ENE-WSW direction of compressive stress, 2) NW-SE trending maximum horizontal principal stress generated conjugate strike-slip faults, and 3) selective reactivations of some structures were derived under the compression by the NE-SW trending principal stress.

Analysis of Some Korean Terminologies on the Reproductive Structures of Seed Plants in Plant Morphology (식물형태학에서 사용하는 종자식물의 생식구조에 관한 한글 용어의 분석)

  • Lee, Kyu Bae
    • Journal of Integrative Natural Science
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    • v.1 no.3
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    • pp.195-209
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    • 2008
  • Some Korean terminologies on reproductive structures of seed plants in plant morphology, written incorrectly in many books, were analysed to propose accurately expressed terminologies. 31 books in areas such as general biology, plant biology, plant morphology, and biological dictionaries and glossaries were selected to analyse the accuracy of the terminologies for reproductive structures in gymnosperms, e.g., cone or strobilus, seed (or ovulate) cone and pollen cone, and conifer(s) or coniferous plants, and for flower structures in angiosperms, e.g., corolla, anther, filament, pistillate (or female) flower and staminate (or male) flower, apocarpous, and syncarpous. The definition and etymology of the terminologies were traced in 4 textbooks of plant anatomy and 2 dictionaries of biology and botany written in English. On the basis of the definition, etymology, and principles for terminology formation according to the International Organization for Standardization (ISO 704:2000), reasonably expressed Korean terminologies were proposed. All of the 8 terminologies examined in this study were included in the glossary of biological terminologies, published by the Korean Association of Biological Sciences in 2005, and designated as an editorial source for science and biology textbooks for middle and high schools by Ministry of Education in 2007. However, the only 1 of the 8 terminologies described in the glossary were consistent with the proposed expression in the present study. These inconsistencies indicated the need for a reassessment of this glossary of biological terminologies. The newly proposed terminologies would facilitate mutual understanding between teachers and students of plant biology.

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Effect of earthquake induced-pounding on the response of four adjacent buildings in series

  • Elwardany, Hytham;Mosa, Beshoy;Khedr, M. Diaa Eldin;Seleemah, Ayman
    • Structural Engineering and Mechanics
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    • v.83 no.2
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    • pp.153-166
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    • 2022
  • Structural pounding due to strong seismic excitations can result in severe damage or even collapse of colliding structures. Many researchers focused on studying the mutual pounding between two adjacent structures while very few researches were concerned with the pounding of a series of structures. This paper aims to study the pounding effect on a series of four buildings having different natural frequencies. The paper also investigates the effect of different arrangements of the four buildings on their pounding response. For this, a mathematical model was constructed using Matlab code where, pounding was modeled using a contact force-based approach. A Non-Linear viscoelastic (Hertzdamp) contact element was used and activated only during the approach period of collision. The mathematical model was validated by comparing its prediction versus experimental results on three adjacent buildings. Then the model was used to study the pounding between four adjacent structures arranged in different sequences according to their natural frequencies. The results revealed that increasing the gap distance generally led to decrease the peak responses of the towers. Such response is somehow different from that predicted earlier by the authors for the case of three adjacent buildings. Moreover, the arrangement of towers has a significant effect on their pounding response. Significant difference between the natural frequencies of adjacent structures increases the pounding forces especially when the more flexible buildings are located at the outer edge of the series. The study points out the need for further researches on buildings in series to gain a better understanding of such complex phenomena.

Novel nonequilibrium microwave emission and current-voltage characteristics of $Bi_2$$Sr_2$Ca$Cu_2$$O_{8+d}$ intrinsic Josephson junction mesas

  • Kim, Sun-Mi;Lee, Kie-Jin;Bae, Myung-Ho;Lee, Hu-Jong;Cha, Deok-Joon;Takayuki Ishibashi;Katsuaki Sato;Kim, Jin-Tae
    • Progress in Superconductivity
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    • v.4 no.2
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    • pp.104-108
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    • 2003
  • We have measured the transport properties of $Bi_2$$Sr_2$$CaCu_2$$O_{8+d}$ (BSCCO) intrinsic Josephson junction mesa. Transport measurements with current flow along the c-axis, perpendicular to the layer of mesa showed multi-branch structures on the current-voltage characteristics. For single intrinsic junctions, the microwave radiation appears in the form of three different modes of oscillations, which include Josephson emission, nonequilibrium broad emission and sharp coherent microwave emission. Mutual phase interactions between two-mesas structures of BSCCO intrinsic Josephson junctions were studied. The results were explained within the framework of the Josephson plasma excitation model due to quasiparticle injection.n.

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