• Title/Summary/Keyword: Reflection Type

Search Result 674, Processing Time 0.023 seconds

Study on $CdIn_{2}Te_{4}$ single crystal growth and electrical characteristics ($CdIn_{2}Te_{4}$ 단결정 성장과 전기적 특성)

  • 홍광준
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.6 no.1
    • /
    • pp.32-43
    • /
    • 1996
  • A $CdIn_{2}Te_{4}$ single crystal was grown by modified veritical bridgman method. The $CdIn_{2}Te_{4}$ single crystal was evaluated to be tetragonal by the powder method. The $CdIn_{2}Te_{4}$ single crystal was confirmed to be grown with its c axis along the lengthe of the boule by the Laue reflection method. Hall effect of $CdIn_{2}Te_{4}$ single crystal was estimated by van der pauw method from 293 K to 30 K. Hall data of the sample perpendicular to c axis was $n=8.75{\times}10^{23}electrons/m^{3},\;R_{H}=7.14{\times}10^{-5}m^{3}/C,\;{\sigma}=176.40{\omega}^{-1}m^{-1},\;{$\mu}=3.41{\times}10^{-2}m^{2}/V.s$ and the sample parallel to c axis was $n=8.61{\times}10^{23}electrons/m^{3},\;R_{H}=7.26{\times}10^{-5}m^{3}/C,\;{\sigma}=333.38{\omega}^{-1}m^{-1}\;and\;{$\mu}=2.42{\times}10^{-2}m^{2}/V.s$ for room temperature. The value of Hall coefficient on sample perpendicular or parallel to c axis were positive. There $CdIn_{2}Te_{4}$ single crystal was p-type semiconductor.

  • PDF

Study on $CuInTe_2$ Single Crystals Growth and Characteristics(I) ($CuInTe_2$ 단결정 성장과 특성연구(I))

  • 유상하;홍광준
    • Korean Journal of Crystallography
    • /
    • v.7 no.1
    • /
    • pp.44-56
    • /
    • 1996
  • CuInTe2 synthesised in a horizontal electric furnace was found to be polycrystalline. Single crystals of CuInTe2 were grown with the vertical Bridgman technique. The structure, Hall effect of the crystals were measured in the temperature range 30 to 293K. Both the polycrystals and single crystals of CuInTe2 were tetragonal in structure. The lattice constants of the polycrytals were measured as a=6.168Å and c=12.499Å, with c/a=2.026, these of the single crystals were measured as a=6.186Å and c=12.453Å, with c/a=2.013. The growth plane of the oriented single crystals was confirmed to be a (112) plane from the back-reflection Laue patterns. The Hall effect of the CuInTe2 single crystals was measured with the method of van der Pauw The Hall data of the samples measured at room temperature showed a carrier concentration of 2.14×1023holes/m3, a conductivity of 739.58Ω-1m-1, and a mobility of 2.16×10 -2m 2/V·s for the sample perpendicular to the c-axis. Values of 1.51×1023holes/m3, 717.55Ω-1m-1, and 2.97×10-2 m2/V·s were obtained for the sample parallel to the c-axis. The Hall coefficients for the samples both perpendicular and parallel to the c-axis in the temperature range 30K to 293K were always positive values. Thus the CuInTe2 single crystal was determined to be a p-type semiconductor.

  • PDF

A Planar Implementation of a Negative Group Delay Circuit (평면 구조의 마이너스 군지연 회로 설계)

  • Jeong, Yong-Chae;Choi, Heung-Jae;Chaudhary, Girdhari;Kim, Chul-Dong;Lim, Jong-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.21 no.3
    • /
    • pp.236-244
    • /
    • 2010
  • In this paper, a planar structure negative group delay circuit(NGDC) is proposed to overcome the limited availability of the component values required for the prototype lumped element(LE) NGDC design. From the prototype LE circuit analysis, general design equations and the conditions to obtain the NGD are derived and illustrated. Then the LE circuit is converted into the planar structure by applying the transmission line resonator(TLR) theory. As a design example, the LE NGDC and the proposed planar structure NGDC are designed and compared. To estimate the commercial applicability, 2-stage reflection type planar NGDC with -5.6 ns of total group delay, -0.2 dB of insertion loss, and 30 MHz of bandwidth together with 0.1 dB and 0.5 ns of the magnitude and group delay flatness, respectively, for Wideband Code Division Multiple Access(WCDMA) downlink band is fabricated and demonstrated. Also, to show the applicability of the proposed NGDC, we have configured a simple signal cancellation loop and obtained good loop suppression performance.

Embodiment of High Impedance Surface of Meta-Material Characteristic Using Symmetrical AMC Structure and Its SAR Analysis (대칭형 인공자기도체 구조를 이용한 메타물질 특성의 고임피던스 표면 구현 및 SAR 특성 분석)

  • Lee, Seungwoo;Lee, Moung-Hee;Rhee, Seung-Yeop;Kim, Nam
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38B no.9
    • /
    • pp.744-750
    • /
    • 2013
  • In this paper, we proposed new type of an artificial magnetic conductor(AMC) structure, which has a high impedance surface for realizing the meta-material characteristics. The designed AMC structure set a goal of 3.2GHz, and the reflector, which consists of periodically arrayed AMCs is fabricated and measured. The high impedance improves the reflection coefficient, decreases the system size and interference, and increases the antenna performance. The structure has embodied the high impedance by the thickness and relative permitivity of the dielectric substrate and the design configuration without the metallic via hole which connects the AMC to the GND. The bandwidth is 150% broader than the similar AMC structures. Also, the distance between the antenna and the AMC reflector is decreased by ${\lambda}/10$ as working as the metal(PEC) reflectors. The antenna radiation characteristics are 3dB increased at 10mm away from reflector by measurement. The proposed reflector could be inserted in the portable mobile devices, and the antenna's performance has improved by the reflector. The specific absorption rate is dramatically decreased over 94% because the back radiation of the antenna is shielded.

Fabrication and Characteristics of High Efficiency Silicon PERL (passivated emitter and rear locally-diffused cell) Solar Cells (PERL (passivated emitter and rear locally-diffused cell) 방식을 이용한 고효율 Si 태양전지의 제작 및 특성)

  • Kwon, Oh-Joon;Jeoung, Hun;Nam, Ki-Hong;Kim, Yeung-Woo;Bae, Seung-Chun;Park, Sung-Keoun;Kwon, Sung-Yeol;Kim, Woo-Hyun;Kim, Ki-Wan
    • Journal of Sensor Science and Technology
    • /
    • v.8 no.3
    • /
    • pp.283-290
    • /
    • 1999
  • The $n^+/p/p^+$ junction PERL solar cell of $0.1{\sim}2{\Omega}{\cdot}cm$ (100) p type silicon wafer was fabricated through the following steps; that is, wafer cutting, inverted pyramidally textured surfaces etching by KOH, phosphorus and boron diffusion, anti-reflection coating, grid formation and contact annealing. At this time, the optical characteristics of device surface and the efficiency of doping concentration for resistivity were investigated. And diffusion depth and doping concentration for n+ doping were simulated by silvaco program. Then their results were compared with measured results. Under the illumination of AM (air mass)1.5, $100\;mW/cm^2$ $I_{sc}$, $V_{oc}$, fill factor and the conversion efficiency were 43mA, 0.6 V, 0.62. and 16% respectively.

  • PDF

Costume Images of the Chosun Period′s Po for Men(Part I ) - Constituent factors, Type, Reflection of the Period - (조선시대 남자 포제에 나타난 복식이미지(제1보) -남자포제 이미지구성 요인 및 유형별, 시기별 복식이미지-)

  • Ju-Yeun Do;Young-Suk Kwon
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.25 no.10
    • /
    • pp.1695-1706
    • /
    • 2001
  • 본 연구는 조선시대 남자 포제(포제에 나타난 복식이미지의 구성요인을 밝히고 남자포제 유형별(철릭, 답호, 직령, 도포, 창의, 주의), 시기별(전기, 중기, 후기) 복식이미지를 알아봄으로서 조선시대 남자포제가 가진 복식이미지를 밝혀 현대 전통복식 디자인에 응용될 수 있는 기초적인 자료를 제공하고자 한다. 의복 자극물은 남자 평상복을 중심으로 하여 조선초기(1477년∼1543년)의 남자 포제로는 철릭, 답호, 직령 3점과 조선중기(18세기)는 도포, 창의 2점, 조선후기(17세기 후기∼20세기 초)는 주의 1점으로 하였고, 당 시대의 정화한 복식이미지를 살펴보기 위해 유물을 복원 제작하여 사용하였다. 이것을 모델에게 착장시켜 슬라이드로 제작한 후 자극물로 제시하였다. 의미지분척도외 구성은 자유언어연상법으로 형용사를 수집하여 23쌍의 형용사쌍을 구성하였다. 패널단은 대학생 남·여 총 600명으로 하였고 자료분석은 SAS을 이용하여 요인분석 분산분석 등을 사용하였다. 1. 조선시대 남자 포제의 요인구조는 품위성 요인(25.2%), 활동성 요인(l4.2%), 관할성 요인(37.9%), 현시성 요인(6.7%), 경연성 요인(5.7%)으로 구성되었으며, 이들 5개 요인의 전체변량 62.7% 중에서 품위성 요인, 활동성 요인, 관할성 요인이 전체변량의 50%를 넘어서 이 세 요인이 남자 포제에서 기본적으로 느껴지는 중요한 요인임을 알 수 있다. 2. 조선시대 남자 포제 유형별 복식이미지의 차이를 알아본 결과, 철릭은 가장 부자연스러운, 주름있는, 곡선적인, 부드러운, 특이한 이미지의 포제로 나타났으며, 답호는 가장 절제된, 직선적인 딱딱한, 특이한 이미지로, 직령은 가장 비활동적인, 답답한, 전통적인 이미지로 도포는 가장 품위있는. 관할한 이미지로 창의는 다른 포제에 비해 평범한, 단순한, 이미지로 주의는 가장 품위 없는, 일상적인, 활동적인, 단순한, 순수한 이미지의 포제로 평가되었다. 모든 남자포제가 전통적, 순수한 이미지의 포제로, 철릭을 제외한 모든 포제가 단순한 이미지로 나타나 조선시대 남자 포제가 공통적으로 가지는 이미지는 단순하고 순수한 이미지를 가지고 있음을 알 수 있다. 3. 남자 포제의 시기별 복식이미지에서는 조선전기(철릭, 답호, 직령)의 포제는 관할성 요인이 높은 의례적인, 관할한, 특이한 이미지로 평가되었고 조선중기(도포, 창의)의 포제는 품위있는, 절제된, 풍성한 이미지로 평가되었으며, 조선후기(주의)의 포제는 활동적인, 단순한, 직선적인 이미지로 나타났다. 따라서 시대별 남자 포제의 이미지는 시대적 여건과 상황에 따라 변화되어 왔으며, 시대에 따라 추구하는 이미지가 달랐다는 것을 알 수 있다.

  • PDF

A study on the recognition and needs of the in-service education of school nurse (보건교사의 현직교육 요구 분석)

  • Kim, Jeong-Mi;Park, Yung-Su
    • The Journal of Korean Society for School & Community Health Education
    • /
    • v.6
    • /
    • pp.89-107
    • /
    • 2005
  • The purposes of this study were to investigate the recognition and the needs and problems of in-service education for school nurse, and to suggest the desirable guidelines, for supples the basic data of in-service education for school nurse to upgraded the quality as school nurse's professional specialist. The subjects of this study were 376 school nurses who were working in Jollanamdo. The research instruments used in this study was 'Needs of In-service Education questionnaire'. 305 collected Data were analyzed with the frequency analysis, $x^2$-test. The conclusions were as follows; First of all, the most important motives for the school nurses to participate in-service education are the enhancement of their specialties on teaching profession, self-realizations as educators, and improvement of health teaching skill. However, the motives to obtain the skill for school management or to obtain a high rank qualification and promotion are quite low. School nurses are generally satisfied with duration, time, place of in-service education, But they are not satisfied with contents of in-service education, professional specialist and understanding of real educational situation of the instructors. On the urgent problem of school nurses, promotion of health teaching skill was highest in the rank, and establishment of firm educational philosophy and a sense of teaching profession, proceed to university and graduate school ranked next, respectively. Second, the need of a school nurses on in-service education direction ranked the application of teachers' character and need, practicable and concrete educational programs, planning of school health development, reinforcement of health education, expansion of practical knowledge and on reflection thought, respectively. The need of a school nurses on in-service education contents(major part) ranked health education, health promoting program of student, knowledge and practice of practical medicine and oriental medicine, consultation process, health education of advanced country, respectively. The need of in-service education supervisory organization, the need for a cities provinces educational office was highest in the rank. The need of in-service education type, duty training ranked high, and abroad training, qualification training, general training ranked next. the need for specialist for lecturer of in-serve education ranked among the highest, along with school nurses and university professor. The need of school nurses on education method(duplication answer), need for conference and discussion teaching was highest in the rank. The need on evaluation method, evaluation through a examination ranked the highest. On the needs of in-service education times, need for vacation during the winter and summer was the highest. As for the duration, 31 to 60 hours in duration of in-service education was need most, and most school nurses need cities and provinces in-service training institute as the location of in-service education. On the organization size, need for 21 to 30 people was the highest, where as need for 41 people was relatively low. Lastly, on the problem of in-service education for school nurses, lack of opportunity of in-service education for school nurses was highest in the rank, and improperness of in-service education contents and method, lack of incentive ranked next, respectively.

  • PDF

Random heterogeneous model with bimodal velocity distribution for Methane Hydrate exploration (바이모달 분포형태 랜덤 불균질 매질에 의한 메탄하이드레이트층 모델화)

  • Kamei Rie;Hato Masami;Matsuoka Toshifumi
    • Geophysics and Geophysical Exploration
    • /
    • v.8 no.1
    • /
    • pp.41-49
    • /
    • 2005
  • We have developed a random heterogeneous velocity model with bimodal distribution in methane hydrate-bearing Bones. The P-wave well-log data have a von Karman type autocorrelation function and non-Gaussian distribution. The velocity histogram has two peaks separated by several hundred metres per second. A random heterogeneous medium with bimodal distribution is generated by mapping of a medium with a Gaussian probability distribution, yielded by the normal spectral-based generation method. By using an ellipsoidal autocorrelation function, the random medium also incorporates anisotropy of autocorrelation lengths. A simulated P-wave velocity log reproduces well the features of the field data. This model is applied to two simulations of elastic wane propagation. Synthetic reflection sections with source signals in two different frequency bands imply that the velocity fluctuation of the random model with bimodal distribution causes the frequency dependence of the Bottom Simulating Reflector (BSR) by affecting wave field scattering. A synthetic cross-well section suggests that the strong attenuation observed in field data might be caused by the extrinsic attenuation in scattering. We conclude that random heterogeneity with bimodal distribution is a key issue in modelling hydrate-bearing Bones, and that it can explain the frequency dependence and scattering observed in seismic sections in such areas.

Relationship between Corporate Governance and CSR Fit (기업지배구조와 기업의 사회적 책임 적합성에 관한 연구)

  • Park, Ji Hyon;Shin, Hyung-Deok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.6
    • /
    • pp.104-112
    • /
    • 2019
  • This study has empirically analyzed how far corporate governance and CSR(Corporate Social Responsibility) fit are related based on prior research indicating that corporate governance is one of the primary factors. Previous research suggested that there may be different types of CSR fit, but there have been only limited number of empirical studies. This study filled this gap by categorizing CSR fit into three types (functional fit, target fit, and size fit) and investigating whether different types have different effects. We used data from the Corporate Social Responsibility White Paper for the 2009-2012 period, as well as the Korea Corporate Governance Service (KCGS) index. As a result, we found that there is a negative (-) relationship between corporate governance and CSR fit(${\beta}=-.023$, p<.05). This can be interpreted that companies with weak corporate governance are attempting to increase the trust level of stakeholders and to reduce the uncertainty of CSR through high-CSR-fitted programs. The test results showed that functional fit and target fit both had negative (-) relationships with corporate governance (${\beta}=-.021$, p<.05; ${\beta}=-.016$, p<.1), while size fit did not have a significant correlation with corporate governance (${\beta}=-.005$, p=.511). The results of this study supported the previous studies' suggestions that CSR fit has different effects on each type, indicating a need for further reflection on the relationship between corporate governance and CSR fit. Also, the results of this study showed that corporations should take a strategic approach to operating CSR fit.

A Study of Hydraulic Characteristics in Front of the Seawall under the Coexistence of Wave and Wind (파랑과 바람 공존장에서의 호안 전면 수리특성 검토)

  • Shim, Kyu-Tae;Kim, Kyu-Han
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.32 no.6
    • /
    • pp.575-586
    • /
    • 2020
  • In this study, a two-dimensional hydraulic model test was conducted to examine the hydraulic phenomena that occur around the seawall when wave and wind coexist. Based on recent seawall repair and reinforcement examples, the experimental section was constructed under the condition of installing wave dissipation blocks on the safety surface of four different representative seawalls. Water level fluctuation, reflection, overtopping and wave pressure characteristics according to external force change were reviewed. It was confirmed that the top concrete shape of the seawall is the most important factor of the hydraulic characteristics that appear in front of the seawall, and the tendency is more pronounced when wind acts. Even in the case of vertical type seawall, when wind of 3 m/s~5 m/s occurs, the amount of overtopping increases to about 5%~12%. In the case of wave pressure, it was confirmed from the experimental results that the value increased from about 1.5 to 2.2 times in front of the top of concrete block. In addition, it was confirmed that when the shape of the seawall was different, the range of change in the hydraulic characteristics appeared larger. Therefore, when designing a seawall of a new shape, a more detailed review of the hydraulic characteristics should be accompanied based on these experimental results.