• Title/Summary/Keyword: Orientation and frequency dependence

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Changes in the Orientation and Frequency Dependence of Target Strength due to Morphological Differences in the Fish Swim Bladder (어류 부레의 형태학적 차이에 따른 음향산란강도의 자세 및 주파수 의존성의 변화)

  • Lee, Dae-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.2
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    • pp.233-243
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    • 2015
  • Controlled broadband acoustic scattering laboratory experiments were conducted using a linear chirp signal (95-220 kHz), and x-ray images of live and model fish with an artificial swim bladder were analyzed to investigate the changes in orientation and frequency dependence of target strength (TS) due to morphological differences in fish swim bladders. The broadband echoes from live and model fish were measured over an orientation angle range of ${\pm}45^{\circ}$ in the dorsal plane and in approximately $1^{\circ}$ increments. The location of nulls in the simulated echo response of the SINC [sinc function] model was overlaid on the TS map, showing the orientation and frequency dependence of fish TS, and they matched very well. It was possible to infer the equivalent fish scattering size (or swim bladder) using the null spacing in the experimentally obtained broadband TS map. Good agreement was observed for inferring the equivalent scattering size between the SINC model and the broadband echoes measured for the three fish species (black scraper Thamnaconus modestus; goldeye rockfish Sebastes thompsoni; and whitesaddled reef fish Chromis notatus). Some results of this inference are discussed.

Orientation dependence of GM-type pulse tube refrigerator (GM형 맥동관 냉동기의 저온부 경사도에 따른 냉각 성능 특성 연구)

  • Ko, Jun-Seok;Kim, Hyo-Bong;Park, Seong-Je;Hong, Yong-Ju;Yeom, Han-Kil;Lee, Chung-Soo;Kang, In-Su;Koh, Deuk-Yong
    • Progress in Superconductivity and Cryogenics
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    • v.14 no.3
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    • pp.48-52
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    • 2012
  • This paper describes experimental study on the orientation dependence of GM-type pulse tube refrigerator with helium and neon as working gas. A pulse tube refrigerator generates refrigeration work with gas expansion by gas displacer in the pulse tube. The pulse tube is only filled with working gas and there exists secondary flow due to large temperature difference between cold-end and warm-end. The stability of secondary flow is affected by orientation of cold-head and thus cooling performance is deteriorated by gas mixing due to secondary flow. In this study, a single stage GM-type pulse tube with orifice valve as a phase control device is fabricated and tested. The fabricated pulse tube refrigerator is tested with two different working gases of helium and neon. First, optimal valve opening and operating frequency are determined with experimental results of no-load test. And then, the variation of no-load temperature as orientation angle of cold-head is measured for two different working gases. Effect of orientation dependence of cold-head as working gas is discussed with experimental results.

Sapphire orientation dependence of the crystallization of ZnO thin films (사파이어 기판의 방향에 따른 ZnO 박막의 결정화 거동)

  • 조태식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.1036-1038
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    • 2001
  • The sapphire orientation dependence of the crystallization of ZnO thin films has been studied using real-time synchrotron x-ray scattering. The amorphous ZnO thin films with a 2400-${\AA}$-thick were grown on sapphire(110) and sapphire(001) substrates by radio frequency magnetron sputtering at room temperature. The amorphous ZnO films were crystallization into epitaxial ZnO(002) grains both on the sapphire(110) and on the sapphire(001) substrates. The epitaxial quality, such as mosaic distribution and crystal domain size, of the ZnO grains on the sapphire(110) is high, similar to that of the ZnO grains on the sapphire(001). With increasing the annealing temperature to 600$^{\circ}C$, the mosaic distribution and the crystal domain size of ZnO(002) grains in the film normal direction was improved and decreased, respectively.

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Social Dependence of Problem Drinking (알코올문제의 사회적 의존에 대한 소고)

  • 김광기
    • Korean Journal of Health Education and Promotion
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    • v.12 no.2
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    • pp.146-161
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    • 1995
  • This study is an effort to bring our attention to social dependence on alcohol, focusing on previous studies of drinking behaviors. Although drinking behavior and problems must be understood in a biopsychosocial framework, a certain aspect is often ignored in alcohol research. A few attention has been paid to social aspect of alcohol abuse or dependence. Social processes of drinking behavior deserve to have same attention as other aspects, psychological and physical aspects of the behavior. Literature show that the interdependence among group members exists to regulate individual's drinking behavior. Such social interactions tend to control drinking level for individual in terms of amounts, frequency, and preference. The drinking level tends to be dependent on desires for heavy drinkers, ignoring variabilities of individual's sensitivity to alcohol. However, such a heavy-oriented tendency in drinking behavior may have different patterns which are function of normative orientation of alcohol. negotiation among group members, and ethnoreligious characteristics. Perspectives from conflict tradition and symbolic interactionism are welcomed to illuminate multi-dimentional aspects of social dependence. Policy implication were discussed from public health perspective.

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A Study on the Hopping Conducting Mechanism in PAN Carbon Fiber (PAN계 탄소섬유의 Hopping 전도기구에 관한 연구)

  • Han, Se-Won;Lee, Hee-Woong
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.65-67
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    • 1989
  • To study hopping conducting mechanism in PAN(polyacrylonitrile) carbon fiber, the temperature and frequency dependence of electrical conductivity and magnetoresistance characteristics were investigated. Electrical conductivity in the range of $60^{\circ}K-300^{\circ}K$ show VRH(variable range hopping) properties which introduced by Mott's theory, and also such properties can be explained by the frequency dependence of electrical conductivity below $5{\times}10^6$ Hz. The negative magnetoresistance observed below 35KG magnetic field, and the properties difference between M40 and T300 with increasing magnetic field is supposed due to on effect connected with crystalline state and orientation of structure.

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Female Adolescents' Clothing Behavior and Hair Style Attitude as Related to Sensation Seeking and Body Image (여고생의 감각추구성향과 신체이미지에 따른 의복행동 및 헤어스타일 태도)

  • Ha Chu-yon;Koh Ae Ran;Chung Mi Sil
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.5 s.142
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    • pp.715-726
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    • 2005
  • The purpose of this study was to identify the effects of the sensation seeking and body image on female adolescents' clothing behavior and hair style attitude. The data was collected from 390 high school girls living in Seoul, via a self·administered questionnaires, and were analyzed by frequency, factor analysis, reliability test, Pearson's correlation, and multiple regression. The results of this study was as follows : 1) Three factors of body images were self appearance evaluation, appearance orientation and fitness orientation. Five factors of clothing attitudes were fashion/clothing interest, clothing exhibition, social approval, psychological dependence on clothing and fashion leadership. And three factors of hair style attitudes were interest in hair style, individuality in hair style and dependency on hair designer. 2) As the result of analyzing the effects of sensation seeking and body image on clothing behavior, fashion/clothing interest was explained by appearance orientation and fitness orientation, and clothing exhibition by sensation seeking and appearance orientation, and social approval by appearance orientation, self appearance evaluation and body cathexis, and fashion leadership by appearance orientation, fitness orientation and self appearance evaluation, and clothing conformity to the self-entertainer by appearance orientation, sensation seeking and fitness orientation, and appearance related delinquency by sensation seeking, appearance orientation, fitness orientation, self appearance evaluation. 3) As the result of analyzing the effects of sensation seeking and body image on hair style attitudes, interest in hair style was explained by the factors such as appearance orientation, sensation seeking, fitness orientation, and body cathexis, and individuality in hair style by appearance orientation, sensation seeking and self appearance evaluation, and dependency on hair designer by body cathexis.

Effects of Growth Temperature on the Properties of ZnO Thin Films Grown by Radio-frequency Magnetron Sputtering

  • Cho, Shin-Ho
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.6
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    • pp.185-188
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    • 2009
  • The effects of the growth temperature on the properties of ZnO thin films were investigated by using X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectrophotometry, and Hall measurements. The ZnO films were deposited by rf magnetron sputtering at various growth temperatures in the range of 100-$400{^{\circ}C}$. A strong c-axis preferred orientation is observed for all of the samples. As the growth temperature increases, the crystalline orientation of the ZnO (002) plane is not changed, but the full width at half maximum gets smaller. The dependence of the electron concentration, mobility, and resistivity on the growth temperature exhibits that the ZnO films have a higher electron concentration at higher temperatures, thus giving them a low resistivity. The optical transmittance and band gap energy, calculated from the spectra of optical absorbance, show a significant dependence on the growth temperature. As for the sample grown at $100{^{\circ}C}$, the average transmittance is about 90% in the visible wavelength range and the band gap is estimated to be 3.13 eV.

An Effect of $O_2/Ar$ Ratio on the Characteristics of RF Magnetron Sputtered $BaTiO_3$ Thin Film (RF Magnetron Sputtering법으로 $BaTiO_3$ 박막 증착시 $O_2/Ar$비가 박막의 특성에 미치는 영향)

  • 안재민;최덕균;김영호
    • Journal of the Korean Ceramic Society
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    • v.31 no.8
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    • pp.886-892
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    • 1994
  • Structural and electrical properties of BaTiO3 thin films deposited on Pt/SiO2/Si substrates by RF magnetron sputtering method have been investigated. Crystallization behavior and electrical properties were studied for the films deposited under various sputtering gas compositions (Ar+O2 gas mixture) and substrate temperatures. All the films deposited above 50$0^{\circ}C$ were all crystallized and their preferred orientation changed from (001) to (111) with the addition of oxygen gas. The dielectric constant of films deposited in pure argon was about 110 and showed little dependence on the substrate temperature. But that was increased as the ratio of O2/Ar increased and its substrate temperature dependence was discernible. The highest dielectric constant reached to 550. In addition, the films deposited in mixed gas showed stable dielectric properties against the frequency and temperature.

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Deposition of ZnO Films for FBAR Device Fabrication

  • Song Hae-il;Mai Linh;Yim Munhyuk;Yoon Giwan
    • Journal of information and communication convergence engineering
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    • v.3 no.3
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    • pp.131-136
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    • 2005
  • The effects of the deposition temperature on the growth characteristics of the ZnO films were studied for film bulk acoustic wave resonator (FBAR) device applications. All films were deposited using a radio frequency (RF) magnetron sputtering technique. It was found that the growth characteristics of the ZnO films have a strong dependence on the deposition temperature from 25 to $350^{\circ}C$. The ZnO films deposited below $200^{\circ}C$ exhibited reasonably good columnar grain structures with a highly preferred c-axis orientation while those above 200°C showed very poor columnar grain structures with a mixed-axis orientation. This study seems very useful for the future FBAR device applications.

Object Recognition Using 3D RFID System (3D REID 시스템을 이용한 사물 인식)

  • Roh Se-gon;Lee Young Hoon;Choi Hyouk Ryeol
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.12
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    • pp.1027-1038
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    • 2005
  • Object recognition in the field of robotics generally has depended on a computer vision system. Recently, RFID(Radio Frequency IDentification) has been suggested as technology that supports object recognition. This paper, introduces the advanced RFID-based recognition using a novel tag which is named a 3D tag. The 3D tag was designed to facilitate object recognition. The proposed RFID system not only detects the existence of an object, but also estimates the orientation and position of the object. These characteristics allow the robot to reduce considerably its dependence on other sensors for object recognition. In this paper, we analyze the characteristics of the 3D tag-based RFID system. In addition, the estimation methods of position and orientation using the system are discussed.