• Title/Summary/Keyword: antennae

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Fine Structure of the Antennal Sensilla of the Millipede Oxidus gracilis(Polydesmida: Paradoxomatidae) (고운까막노래기(Oxidus gracilis) 안테나 감각모의 미세구조)

  • Chung, Kyung-Hwun;Moon, Myung-Jin
    • Applied Microscopy
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    • v.37 no.4
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    • pp.231-238
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    • 2007
  • Although the biological significance of the antennal sensillae to millipedes are widely understood, the structure and function of the antennal sensillae are still not clear and more precise analysis is required. Thus, this study initiate to reveal the fine structural characteristics of various sensory receptors on the antennae of millipede Oxidus gracilis were observed with field emission scanning electron microscopy(FESEM). The antennae generally include eight segments, called articles. On the surface of the antennae, there are a variety of sensory receptors which include olfactory and mechanical receptors. We could identify four different types of antennal sensillae in O. gracilis as follows: apical cone sensilla, trichoid sensilla, chatiform sensilla and basiconic sensilla. The most prominent is four large spital cone sensillae on distal tip of the 8th article. Both of trichoid and chaetiform sensillae are abundantly observed at the most of antennal articles. These sharply pointed structures are inclined and slightly curved toward the apex of the sensilla. The basiconic sensilla are further divided into three subtypes: large basiconic sensilla($Bs_1$), small basiconic sensilla($Bs_2$) and spiniform sensilla($Bs_3$). The $Bs_1$ is located at the 5th and 6th articles, while the $Bs_2\;and\;Bs_3 can be seen at the 5th and 7th articles, respectively.

Morphological Study of the Suction Trap in Aquatic Utricularia japonica (수생형 통발(Utricularia japonica)의 흡입식 포충낭 형태 연구)

  • Kim, In-Sun
    • Applied Microscopy
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    • v.40 no.2
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    • pp.109-116
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    • 2010
  • Morphology and microstructure of the suction trap in aquatic Utricularia japonica were examined using scanning electron microscopy. Branched stems bear numerous suction traps without root formation. The traps are derived axillary from the node, and their antennae and appendages extend in a peculiar fashion. The trap walls are thin, two-celled, parenchyma tissue and simple, small glands are scattered in both internal and external surface of the trap. The entrance of the trap is surrounded by one pair of dorsal antennae and ventral appendages, where the former guides the prey to the entrance. Trap door is situated below the entrance and numerous sessile and stalked capitate trichomes cover the entrance and even on the door surface. The capitate trichomes are secretory, but four trigger hairs formed on the central areas of the door are not. They are believed to function in activating and tripping the trap door. A specialized region of the threshold come in contact with the lower portion of the door upon closing. The secretory capitate trichomes near this region are responsible for producing and secreting a mucilage-like substance which composes the velum. Two-armed bifid glands are located in the interior side of the threshold, while four-armed quadrifid glands are considerably numerous occurring over the entire inner trap wall. Bifid and quadrifid glands develop semi-spherical basal cells that connect them to the inner wall surface. Antennae, trigger hairs, capitate trichomes, bifid and quadrifid glands are more important structures in the carnivory of U. japonica.

Detecting System of Moving Object Using Directional Antennae (지향성 안테나를 이용한 이동체 감지 시스템)

  • 이성필;김종수;윤여경
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.101-104
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    • 1996
  • A new detecting system for moving objects of coastal region has been designed by directional antenna and driving circuits. The designed system has been investigated by CAD for linear and planar antenna arrays of various radiating elements for antenna simulations and by P-spice of device simulations. For detecting the displacement of moving objects, we constructed four wideband dipole antenna, diode switching circuit, mixer, filter and amplifier. The results of antenna receiver were shown a possibility of distance measuring system through phase difference of radiation patterns in antenna simulation

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The Design and Fabrication of Antennae for GPS using Dialectic Ceramic (유전체 세라믹을 이용한 GPS용 안테나의 설계 및 제작)

  • 허영규;이헌영;윤중락;권정열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.153-157
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    • 1997
  • This paper presents a patch antenna design method using microwave dielectric ceramic substrate. Before manufactirung the GPS(Global Positioning System)antenna such contents as input impedence resonent frequency and quality factor and efficiency are surveyed theolitically for design and parameters for manufacturing the antenna are found.

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A Study on the Hazard Analyses of Construction for Base Station of Mobile Communication (이동통신 기지국 공사의 위험요인 분석에 관한 연구)

  • Lee, Sang-wook;Kwon, Soon-joon;Yi, Young-seop
    • Journal of the Korean Society of Safety
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    • v.30 no.5
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    • pp.44-51
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    • 2015
  • As the domestic communication industry has been made rapid progresses, the construction of base stations are also expanded yearly from more than 86,000 ones in the year 2005 to over 300,000 ones in 2013. While the new construction and rebuilt works have been rapidly increased, there has been not tried about the analysis as well as the control of hazards for the construction works. This study is conducted to do not only the focus interview for 27 expert groups who are engaged in the construction works and safety, but also the questionnaires for AHP analysis which is suggested by the Korea Occupational Safety and Health Agency for 92 persons who are engaged in the construction works in order to analyze the hazards of construction works for base stations. The high ranked risk works which are acquired from the two methods are fall under installation of antennae, struck by the hand tools and construction materials under installation of antennae, fall during going up and down the steel tower and telegraph poles and the fall by electric shock during the underground cable works. The control for the above hazards are the installation of fall protection equipments, the installation of safety nets for falling objects and the installation of protection equipment of electric shock.

Performance Experiment of the Angle Deception of Cross-Eye Jamming against a Monopulse Sensor (모노펄스 센서에 대한 크로스 아이 재밍기법의 각도기만 성능 실험)

  • Jang, Yeonsoo;Park, Jintae;Lee, Changhoon;Kim, In-sun;Kim, Ghiback;Cho, Sangwang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.2
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    • pp.146-149
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    • 2018
  • A monopulse sensor is used to estimate the angle of a target with respect to each received single pulse. It is well known that the cross-eye technique can result in an angle deception effect against monopulse sensors. To verify this effect, we propose a test environment configuration for the angle deception using monopulse receiving antennae and cross-eye transmitters in an anechoic chamber. Using the proposed test environment configuration, we have measured powers of the sum and difference of the signals received by the monopulse receiving antennae when the distance of the two cross-eye transmitters is varied. Finally, the angle deception performance related to the powers of the sum and difference signals was analyzed.

A New Record of Roeselia triangulalis (Lepidoptera: Nolidae) from Korea

  • Choi, Sei-Woong
    • Animal Systematics, Evolution and Diversity
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    • v.27 no.3
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    • pp.274-276
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    • 2011
  • A nolid species, Roeselia triangulalis (Leech) is reported for the first time from Korea. Two males were collected from Jeju Island, South Korea. Roeselia triangulalis can be distinguished by the bipectinate male antennae, broad frons, long labial palpi, costally dark brownish spot and the rounded dark brownish postmedial line of forewing. In the male genitalia, the long saccus, the slender valve with distally expanded and spine-like harpe and long spinular cornutus of vesica are distinguishing characters. In the female genitalia, the simple sterigma, the long ductus bursae and the large ovate corpus bursae with a lip-shaped signum are distinguishing characters. Diagnosis and description of the species are given with the figures of the male genitalia.

Design of Broadband Microstrip Patch Antenna for Mobile Communications

  • Kim, Jang-Wook;Jeon, Joo-Seong
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.4
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    • pp.67-74
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    • 2017
  • The objective of this paper is to design broadband microstrip patch antenna for mobile communication service. The enhanced features were confirmed and proved by comparing the proposed antenna with the antennae that have been reported in the relevant literatures. The experimental results show that the impedance bandwidth(VSWR ${\leq}2$) of 19.6%(fo=1,920MHz) and the peak gain of 5.53dBi(at 1,900MHz) were obtained by the mobile communication service frequency band. The proposed antenna had the impedance bandwidth of about 3.1% larger than that of the reported microstrip antenna.

Physical Principles of Magnetic Resonance Imaging in Animal (동물에서 자기 공명 영상 진단의 물리적 원리)

  • 김종규
    • Journal of Veterinary Clinics
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    • v.16 no.1
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    • pp.75-79
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    • 1999
  • Magnetic resonance imaging (MRI) is an imaging technique used to produce high quality images of the inside of the animal body. MRI is based on the principles of nuclear magnetic resonance (NMR) and started out as a tomographic imaging technique, that is it produced an image of the NMR signal in a thin slice through the animal body. The animal body is primarily fat and water, Fat and water have many hydrogen atoms. Hydrogen nuclei have an NMR signal. For these reasons magnetic resonance imaging primarily images the NMR signal from the hydrogen nuclei. Hydrogen protons, within the body align with the magnetic field. By applying short radio frequency (RF) pulses to a specific anatomical slice, the protons in the slice absorb energy at this resonant frequency causing them to spin perpendicular to the magnetic field. As the protons relax back into alignment with the magnetic field, a signal is received by an RF coil that acts as an antennae. This signal is processed by a computer to produce diagnostic images of the anatomical area of interest.

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