• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.397-400
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• 2009

본 연구는 국가교육과정에서 문자 교육 입문기인 초등학교 1학년을 대상으로 하여 글자크기와 성별에 따른 가독성 차이를 알아보기 위한 연구로서 초등학교 1학년 학생에게 교과서 본문에 쓰이는 글자 크기는 실제 학습에 있어 가독성에 유의미한지 초등학교 1학년 학생들은 성별에 따라 본문 읽기는 어떤 다른 가독성 효과를 보이는지에 대하여 살펴보았다. 본 논문 주제에 대한 접근방법으로 먼저, 가독성의 개념, 가독성에 영향을 미치는 요소, 가독성 측정방법에 대한 고찰과 함께 초등학교 1학년 교과서 본문 글자 크기와 성별에 따라 가독성이 어떻게 달라지는지에 대하여 실험을 통하여 검증하였다. 초등학교 1학년 대상으로 글자 크기에 따른 가독성 차이를 살펴봄으로써 현행 교과서의 체제 개선에 필요한 기초 자료를 마련하고 성별에 따라 가독성 효과가 어떻게 차이가 나는지 살펴봄으로써 성별에 따른 남녀의 언어 발달 차이에 대한 이해와 성별에 따른 읽기 지도 전략에 시사점을 제공하고자 한다.

• ETRI Journal
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• v.28 no.2
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• pp.216-218
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• 2006

This letter presents the design for a low-profile planar inverted-F antenna (PIFA) that can be stuck to metallic objects to create a passive radio frequency identification (RFID) tag in the UHF band. The designed PIFA, which uses a dielectric substrate for the antenna, consists of a U-slot patch for size reduction, several shorting pins, and a coplanar waveguide feeding structure to easily integrate with an RFID chip. The impedance bandwidth and maximum gain of the tag antenna are about 0.3% at 914 MHz for a voltage standing wave ratio (VSWR) of less than 2 and 3.6 dBi, respectively. The maximum read range is about 4.5 m as long as the tag antenna is on a metallic object.

• ETRI Journal
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• v.34 no.2
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• pp.284-287
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• 2012

Quantum-dot cellular automata (QCA) is one of the few alternative computing platforms that has the potential to be a promising technology because of higher speed, smaller size, and lower power consumption in comparison with CMOS technology. This letter proposes an optimized full comparator for implementation in QCA. The proposed design is compared with previous works in terms of complexity, area, and delay. In comparison with the best previous full comparator, our design has 64% and 85% improvement in cell count and area, respectively. Also, it is implemented with only one clock cycle. The obtained results show that our full comparator is more efficient in terms of cell count, complexity, area, and delay compared to the previous designs. Therefore, this structure can be simply used in designing QCA-based circuits.

• ETRI Journal
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• v.29 no.1
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• pp.120-123
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• 2007

In this letter, we address the problem of resource allocation with efficiency and quality of service (QoS) support in uplink for a wireless CDMA network supporting real-time (RT) and non-realtime (NRT) communication services. For RT and NRT users, there are different QoS requirements. We introduce and describe a new scheme, namely, traffic aided uplink opportunistic scheduling (TAUOS). While guaranteeing the different QoS requirements, TAUOS exploits the channel condition to improve system throughput. In TAUOS, the cross-layer information, file size information, is used to improve fairness for NRT users. Extensive simulation results show that our scheme can achieve high system throughput in uplink wireless CDMA systems, while guaranteeing QoS requirements.

• Child Studies in Asia-Pacific Contexts
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• v.2 no.1
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• pp.45-60
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• 2012

This project examined 2, 3, and 4-year-old children (N = 34) in a university campus child care setting to assess their understanding of the graphic features they use in their emergent writing (to distinguish it from a drawing of the same referent). The graphic features present in samples of the children's work were examined and compared to the graphic features children could identify through verbal and nonverbal communication. We examined the frequencies of graphic feature identification, as well as significant differences between graphic feature usage and graphic feature identification. The most frequently used graphic features were linearity, unidirectionality, and small size of units. The most frequently identified graphic feature was conventional letter. Overall, children used significantly more graphic features than they were able to identify. Significant relationships comparing the 2-year-old group and 4-year-old group's usage and identification were also found. The findings are discussed in terms of their application to early childhood classrooms. Teachers can apply these findings when engaging children in conversations about their emergent writing; these discussions are explored as a beneficial teaching tool.

• Journal of electromagnetic engineering and science
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• v.14 no.4
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• pp.342-345
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• 2014

An active frequency doubler monolithic microwave integrated circuit (MMIC) for E-band transceiver applications is presented in this letter. This MMIC has been fabricated in a commercial $0.1-{\mu}m$ GaAs pseudomorphic high electron mobility transistor (pHEMT) process on a 2-mil thick substrate wafer. The fabricated MMIC chip has been measured to have a high output power performance of over 13 dBm with a high fundamental leakage suppression of more than 38 dBc in the frequency range of 71 to 86 GHz under an input signal condition of 10 dBm. A microstrip coupled line is used at the output circuit of the doubler section to implement impedance matching and simultaneously enhance the fundamental leakage suppression. The fabricated chip is has a size of $2.5mm{\times}1.2mm$.

• ETRI Journal
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• v.30 no.4
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• pp.615-617
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• 2008

A novel and compact elliptic-function bandpass filter is proposed in this letter. The techniques of slot etching and the addition of open stubs are applied to enhance the self-inductance and self-capacitance of hexagonal open-loop resonators. Thus, size reduction and improved transmission performance are obtained. Compared to the performance of the conventional design, the central frequency and insertion loss are reduced by 28% and 3.1 dB, respectively. Measurements show that the proposed filter has a fraction bandwidth of 23% at the central frequency of 1.84 GHz, and its insertion loss in the passband is less than -1.5 dB. The bandpass filter occupies only 12 mm${\times}$21.2 mm (approximately $0.24{\lambda}_g{\times}0.14{\lambda}_g$).

• ETRI Journal
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• v.33 no.2
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• pp.283-286
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• 2011

Path loss plays fundamental roles in system design, spectrum management, and performance evaluation. The traditional path loss model has a slight inconvenience; it depends on the unknown distance. In this letter, we explore the probability distribution function (PDF) of path loss in an indoor office environment by randomizing out the distance variable. It is shown that the resulting PDF is not Gaussian-like but is skewed to the right, and both the PDF and the moments are related to the size of the office instead of the unknown distance. To be specific, we incorporate the IEEE 802.15.4a channel parameters into our model and tabulate the cumulative distribution function with respect to different room sizes. Through a simple example, we show how our model helps a cognitive spectrum user to infer path loss information of primary users without necessarily knowing their transmitter-receiver distance.

• ETRI Journal
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• v.32 no.4
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• pp.610-613
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• 2010

This letter presents the design of a novel multiband USB dongle antenna with a compact ground plane. The radiating patch is composed of a modified meander-line monopole and a shorted loop to generate a dual-broadband resonance. The proposed antenna supports WiBro, Bluetooth, WLAN, WiMAX, and S-DMB services. The total dimensions of the fabricated antenna are 10 mm ${\times}$ 45 mm ${\times}$ 1 mm, the most compact size among multiband USB dongle antennas reported to date. The measured 10 dB reflection loss bandwidths are 20.8% (2.24 GHz to 2.76 GHz) and 20.2% (4.86 GHz to 5.95 GHz). The measured peak gain is 2.97 dBi, and efficiency is higher than 58%. In addition, the radiation pattern approximates an omnidirectional pattern.

• Journal of electromagnetic engineering and science
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• v.14 no.3
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• pp.317-319
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• 2014

In this letter, a small-loop antenna for a mobile UHF RFID device is proposed. To achieve size reduction, a ferrite sheet optimized for a 900 MHz band is applied. The overall dimensions of the antenna are $46mm{\times}35mm{\times}0.24mm$, and it has a bandwidth of 45 MHz with a return loss of less than -6 dB. The proposed antenna satisfies near and far field UHF EPC global frequency band communications (902-928 MHz).