• Title/Summary/Keyword: Korean Education Center

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New Harmonic Suppressed Microstirp Ring Bandpass Filters

  • Park, Hyun-Joo;Kim, Jae-Hyuk;Park, Ji-Yong;Lee, Jong-Chu;Kim, Jong-Heon;Lee, Byung-Je;Kim, Nam-Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.5
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    • pp.697-706
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    • 2000
  • In this paper, new bandpass filters that are composed of microstrip ring resonators with the center frequency of 5.775 GHz and the bandwidth of 100 MHz are presented. For the suppression of the unnecessary harmonics, lowpass filters are inserted into the feedlines and ring resonator itself, respectively These bandpass filters show good microwave characteristics with the harmonic suppression ratio of about 39 dB and 35 dB, respectively. Also, the varactor-tuned microstip ring bandpass filter with harmonic suppression is suggested and the tuning bandwidth of more than 450 MHz is obtained.

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Novel K/Ka Bandpass Filters using LIGA Micromachined Process

  • Park, K. Y.;Park, J. Y.;Choi, H. K.;Lee, J.C.;Lee, B.;Kim, J. H.;Kim, N. Y.;Park, J. Y.;Kim, G. H.;Kim, D. W.;Bu, J. U.;Chung, K. W.
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.6
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    • pp.969-975
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    • 2000
  • New class of three dimensional (3-D) micromachined microwave planar filters at K and Ka-band are presented using LIGA micro-machined process. The K-and Ka-band filters show wide bandpass characteristics of~36% and ~39% with the insertion loss 1.26dB at 19.11GHz and 1.7dB at GHz, respectively. These filters can be applicable in high power MMIC of MIMIC.

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Cascode Low Noise Amplifiers with Coplanar Waveguide Structure for Wireless LAN Application

  • Kim, Jong-Ho;Kim, Ki-Byoung;Lee, Jong-Chul;Kim, Jong-Heon;Lee, Byungje;Kim, Nam-Young
    • Journal of electromagnetic engineering and science
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    • v.3 no.1
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    • pp.12-16
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    • 2003
  • In this paper, low noise amplifiers with coplanar waveguide structure are presented for Wireless LAN data communication application. For comparison of microwave performance, LNAs of cascode type and balanced type using cascode cell with the same substrate and same bias conditions are designed and implemented. A cascode type of LNA shows the gain of 12.45 ㏈, input return loss of 11.63 ㏈, and noise figure of 1.52㏈. A balanced type of LNA using cascode cell shows the gain of 6.58 ㏈, input return loss of 16.6 ㏈, and noise figure of 1.18 ㏈.

A Survey Study of Perceptions for Students, Teachers and Parents Regarding Building Creativity Center (창의성센터 건립을 위한 학생, 교사 및 학부모의 인식 조사)

  • Lee, Sung-Hee;Choi, Sun-Young;Jhun, Young-Seok
    • Journal of Korean Elementary Science Education
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    • v.31 no.2
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    • pp.177-187
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    • 2012
  • The purpose of this study was to acquire a better of how creativity center is perceived among students, teachers and parents by administering a questionnaire. A total of 320 people participated in this survey. We developed the questionnaire which as categorized by four specific areas: 1) people's overall perceptions of creativity education; 2) the way of using the creativity center 3) programing of creativity center 4) space composition of the creativity center. The summary of survey results included; firstly, people had paid attention to creativity education and creativity education; secondly, they want to make use of creativity center with informal learning and extra-curriculum; thirdly, they prefer to participate in many experience activities such as camp or experiments; lastly, they more need creativity experience program and utilization of DIY education. In conclusion, students, teachers and parents recognized creativity center is needed. Therefore, more intensive research and follow-up study on building creativity center should be highly considered.

The Degree of Safety Education Requirement for Younger Children in Child Daycare Center Teachers (보육시설 아동에 대한 교사의 안전교육 요구도)

  • Kim, Shin-Jeong;Kim, Yae-Young;Kim, Sung-Hee;Park, Hyun-Jung;Kang, Kyung-Ah
    • The Journal of Korean Academic Society of Nursing Education
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    • v.19 no.2
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    • pp.137-150
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    • 2013
  • Purpose: The purpose of this study was to identify the degree of safety education requirement in child daycare center teachers. Method: The data using questionnaire were collected from eight child daycare centers located in Seoul, Gyounggi-Do, and Kwangwon-Do. Final participants were 133 child daycare center teachers. Results: The degree of safety education requirement were as follows: education need of safety knowledge ($4.26{\pm}.50$), safety education need of daycare center ($3.29{\pm}.60$), recognition about safety education training ($3.94{\pm}.58$), and confidence of safety care practice ($2.75{\pm}.43$). There is significant correlation between education need of safety knowledge and safety education need of daycare center (r=.495, p<.001), education need of safety knowledge and recognition about safety education training (r=.555, p<.001), education need of safety knowledge and confidence of safety care practice (r=.201, p=.020), safety education need of daycare center and recognition about safety education training (r=.464, p<.001), and recognition about safety education training and confidence of safety care practice (r=.187, p=.032). Conclusion: On this study, child daycare center teachers' safety education requirement was relatively high. It is recommended that safety education for them should be done for children's healthy life.