• Title/Summary/Keyword: R/F communication

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A Study on the High Quality and Low Cost Fabrication Technology of ZnO Thin Films for Solar Cell Applications (태양전지 응용을 위한 고품위 및 저가격 ZnO 박막 제조에 관한 연구)

  • Lee, Jae-Hyeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.191-196
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    • 2010
  • Aluminum doped zinc oxide (AZO) films have been prepared on Coming 7059 glass substrates by r.f. magnetron sputtering method. A powder target instead of a conventional sintered ceramic target was used in order to improve the utilization efficiency of the target and reduce the cost of the film deposition process. The influence of sputter pressure on the structural, electrical, and optical properties of AZO films were studied. The AZO films had hexagonal wurtzite structure with a preferred c-axis orientation, regardless of sputter pressure and target types. The crystallinity and degree of orientation was increased by increasing the sputter pressure. For higher sputtering pressures, a reduction of the resistivity was observed due to a increase on the mobility and the carrier concentration. The lowest resistivity of $6.5{\times}10^{-3}\;{\Omega}-cm$ and the average transmittance of 80% can be obtained for films deposited at 15 mTorr.

An Improved PAPR Reduction Using Sub-block Phase Weighting (SPW) Method in OFDM Communication System (OFDM 시스템에서 SPW(Sub-Block Phase Weighting) 기법을 이용한 개선된 PAPR 저감 기법)

  • Kim Sun-Ae;Kang Yeong-Cheol;Suh Jae-Won;Ryu Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.11 s.102
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    • pp.1123-1130
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    • 2005
  • In this paper, we propose an improved side information processing scheme which is important in the sub-block phase weighting(SPW) method for the peak-to-average power ratio(PAPR) reduction. SPW method is to divide the input OFDM subchannels into several subblocks and to multiply phase weighting with each subblocks, properly for the reduction of the peak power. SPW method is similar to the conventional PTS method when the number of sub-carriers, signal modulation format and the number of subblocks are the same. However, unlike the conventional PTS(Partial Transmit Sequence) and SLM(Selected Mapping) method using many stages of IFFT(Inverse Fast Fourier Transform), SPW method only needs one IFFT. Although PAPR can be reduced by SPW method, complex computation burden still remains. In this paper the flipping algorithm and the full iteration algorithm are used f3r the phase control method. Through the computer simulation, we analyze and discuss the properties and the performance of the suggested method.

Evaluation of a Traditional Korean Medicine Content Factor and Satisfaction with the Drama "Daejanggeum" (드라마 "대장금"의 한의학 콘텐츠 요소 및 만족도 평가)

  • Kim, Song-Yi;Kim, Ho-Sun;Nam, Min-Ho;Li, Yuejuan;Chung, Hung-Chiang;Park, Hi-Joon;Lee, Hye-Jung;Chae, Youn-Byoung
    • Journal of Acupuncture Research
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    • v.27 no.1
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    • pp.11-20
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    • 2010
  • Objectives : The study was performed to evaluate a traditional Korean Medicine content in drama "Daejanggeum". Methods : One hundred sixty-nine participants in Taiwan responded to the survey with 10 items, regarding components of success of drama "Daejanggeum". Principal component factor analysis and multiple regression analysis were performed to identify the possible factors to satisfaction with watching drama "Daejanggeum". Results : Factor analysis revealed that dramatic factor(44.8%), content factor(12.3%), and cultural factor(11.3%) were the most important factors to success of drama "Daejanggeum". Multiple regression analysis showed that dramatic factor(beta = .342), content factor(beta = .278), and cultural factor(beta = .131) were associated with the satisfaction with watching drama "Daejanggeum"($R^2$ = .394, with F = 32.280, p<.001). Conclusions : This study demonstrated that dramatic factor, content factor, and cultural factor are the most important factors associated with satisfaction with drama "Daejanggeum" in Taiwan. These findings suggest that a traditional Korean Medicine as a content factor would be very influential in enhancing the possibility of success of drama.

Design, Analysis, and Equivalent Circuit Modeling of Dual Band PIFA Using a Stub for Performance Enhancement

  • Yousaf, Jawad;Jung, Hojin;Kim, Kwangho;Nah, Wansoo
    • Journal of electromagnetic engineering and science
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    • v.16 no.3
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    • pp.169-181
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    • 2016
  • This work presents a new method for enhancing the performance of a dual band Planer Inverted-F Antenna (PIFA) and its lumped equivalent circuit formulation. The performance of a PIFA in terms of return loss, bandwidth, gain, and efficiency is improved with the addition of the proposed open stub in the radiating element of the PIFA without disturbing the operating resonance frequencies of the antenna. In specific cases, various simulated and fabricated PIFA models illustrate that the return loss, bandwidth, gain, and efficiency values of antennas with longer optimum open stub lengths can be enhanced up to 4.6 dB, 17%, 1.8 dBi, and 12.4% respectively, when compared with models that do not have open stubs. The proposed open stub is small and does not interfere with the surrounding active modules; therefore, this method is extremely attractive from a practical implementation point of view. The second presented work is a simple procedure for the development of a lumped equivalent circuit model of a dual band PIFA using the rational approximation of its frequency domain response. In this method, the PIFA's measured frequency response is approximated to a rational function using a vector fitting technique and then electrical circuit parameters are extracted from it. The measured results show good agreement with the electrical circuit results. A correlation study between circuit elements and physical open stub lengths in various antenna models is also discussed in detail; this information could be useful for the enhancement of the performance of a PIFA as well as for its systematic design. The computed radiated power obtained using the electrical model is in agreement with the radiated power results obtained through the full wave electromagnetic simulations of the antenna models. The presented approach offers the advantage of saving computation time for full wave EM simulations. In addition, the electrical circuit depicting almost perfect characteristics for return loss and radiated power can be shared with antenna users without sharing the actual antenna structure in cases involving confidentiality limitations.

Antenna-Diplexer Module for Cellular/SDMB Band Using LTCC Technology (LTCC 공법을 사용한 Cellular/SDMB 안테나-다이플렉서 모듈)

  • Ha, Jeung-Uk;Chang, Ki-Hun;Yoon, Young-Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.7
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    • pp.774-783
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    • 2007
  • This paper presents an integrated packaging antenna-diplexer module for wireless communication systems in the Cellular and SDMB band. The design and the realization of the proposed one are experimentally analyzed and discussed. It consists of a dual-resonance antenna and a diplexer with a multi-layer LTCC(${\varepsilon}_r=7.8,\;tan\;{\delta}=0.0043$) technology with integration capability and low loss. The dual-resonance antenna of the proposed module has the meander line structure for size reduction and has the shorting structure of an inverted F antenna to achieve good impedance matching. The diplexer of the proposed module was designed with the combination of low pass filter(LPF) and high pass filter(HPF). Decreasing the mutual interference between them provides a high isolation characteristic. The proposed antenna-diplexer module with dimensions of $27.5{\times}12.0{\times}2.2mm$ operates within a range from 813 MHz to 902 MHz for the cellular band and from 2,586 MHz to 2,655 MHz for the SDMB band. And the measured gain of the fabricated module is -1.96 dBi for Cellular band and -5.43 dBi for SDMB band. The parameters for the antenna-diplexer module are investigated and the several performances are discussed.

Analysis of Voice Color Similarity for the development of HMM Based Emotional Text to Speech Synthesis (HMM 기반 감정 음성 합성기 개발을 위한 감정 음성 데이터의 음색 유사도 분석)

  • Min, So-Yeon;Na, Deok-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.9
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    • pp.5763-5768
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    • 2014
  • Maintaining a voice color is important when compounding both the normal voice because an emotion is not expressed with various emotional voices in a single synthesizer. When a synthesizer is developed using the recording data of too many expressed emotions, a voice color cannot be maintained and each synthetic speech is can be heard like the voice of different speakers. In this paper, the speech data was recorded and the change in the voice color was analyzed to develop an emotional HMM-based speech synthesizer. To realize a speech synthesizer, a voice was recorded, and a database was built. On the other hand, a recording process is very important, particularly when realizing an emotional speech synthesizer. Monitoring is needed because it is quite difficult to define emotion and maintain a particular level. In the realized synthesizer, a normal voice and three emotional voice (Happiness, Sadness, Anger) were used, and each emotional voice consists of two levels, High/Low. To analyze the voice color of the normal voice and emotional voice, the average spectrum, which was the measured accumulated spectrum of vowels, was used and the F1(first formant) calculated by the average spectrum was compared. The voice similarity of Low-level emotional data was higher than High-level emotional data, and the proposed method can be monitored by the change in voice similarity.

Design and Performance Analysis of EU Directory Service (ENUM 디렉터리 서비스 설계 및 성능 평가)

  • 이혜원;윤미연;신용태;신성우;송관우
    • Journal of KIISE:Information Networking
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    • v.30 no.4
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    • pp.559-571
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    • 2003
  • ENUM(tElephon NUmbering Mapping) is protocol that brings convergence between PSTN Networks and IP Networks using a unique worldwide E.164 telephone number as an identifier between different communication infrastructure. The mechanism provides a bridge between two completely different environments with E.164 number; IP based application services used in PSTN networks, and PSTN based application services used in IP networks. We propose a new way to organize and handle ENUM Tier 2 name servers to improve performance at the name resolution process in ENUM based application service. We build an ENUM based network model when NAPTR(Naming Authority PoinTeR) resource record is registered and managed by area code at the initial registration step. ENUM promises convenience and flexibility to both PSTN and IP users, yet there is no evidence how much patience is required when users decide to use ENUM instead of non-ENUM based applications. We have estimated ENUM response time, and proved how to improve performance up to 3 times when resources are managed by the proposed mechanism. The proposition of this thesis favorably influences users and helps to establish the policy for Tier 2 name server management.

A Study of Folk Remedies in Type II Diabetic Patients (우리나라 당뇨환자들의 민간요법 실태)

  • 조미란;조여원
    • Journal of Nutrition and Health
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    • v.31 no.7
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    • pp.1151-1157
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    • 1998
  • Many type II diabetic patients use folk remedies to. treat diabetes in Korea. The physiology, pathology, usage, and prescriptions of folk remedies are not well established, and the effects of those remedies were handed down by word of mouth of experienced persons. Most of these remedies can cause unexpected side effects if consumed in large amounts since patients lack scientific backgrounds and the precise effects as well as the possible side effects have not been proven. The purpose of this survey was to investigate the prevalence of diabetic f31k remedies used by adult diabetic patients who use diet therapy to treat diabetes. This information can be used for a basic scientific approach to diabetic f31k remedies. The results of the survey were as follows : 1) Thiry-nine patients(53.4%) out of a total of 75 patients, answered that they used folk remedies. 2) There were 54 kinds of folk remedies f3r diabetes, and the most popular ones are silk worm powder, red jinseng, silkworm pupa, raw lentils, and cabbage, that to accounted for 97.4% of the experienced group. 3) The most common way to be exposed to folk remedies were recomnendations by friends and relatives, and through the mass communication such as TV, newspaper, magazine. As fir as the effects of the flok remedies goes, 17% answered that they experienced positive effects in controlling blood glucose levels and 5.7% reported negative effects. Moreover, 17.1% answered that they experienced side effects like stomach ache and bloating. 4) The 82.9% of the experienced group answered that they used silkworm powder, which was the most popular one in folk remedies. 5) 75% of the experienced group patients showed positive responses to folk remedies, saying that they will try new folk remedies if introduced. Even 66.7% of inexperienced group showed their interest saying that they will try new folk remedies.

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Microwave Dielectric Properties of La2O3-B2O3-TiO2 Glass-Ceramic and BaNd2Ti5O14Ceramic System for LTCC Application (저온동시소성(LTCC)을 위한 결정화 유리(La2O3-B2O3-TiO2계)와 BaNd2Ti5O14 세라믹을 이용한 마이크로파 유전체 특성)

  • 황성진;김유진;김형순
    • Journal of the Korean Ceramic Society
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    • v.41 no.8
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    • pp.599-604
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    • 2004
  • The LTCCs (Low-Temperature Co-fired Ceramics) are very important for electronic industry to build smaller RF modules and to fulfill the necessity for miniaturization of devices in wireless communication industry. The dielectric materials with sintering temperature $T_{sint}$<90$0^{\circ}C$ are required. In this study, BaO-N $d_2$ $O_3$-Ti $O_2$ (BNT : 20∼40 wt%) for ceramic materials and L $a_2$ $O_3$- $B_2$ $O_3$-Ti $O_2$ (LBT : 80∼60 wt%) for crystallizable glasses were used. The glass/ceramic composites were investigated for sintering behavior, phase evaluation, densities, interface reaction and microwave dielectric properties. It was found that the addition LBT glass frist significantly lowered the sintering temperature to below 90$0^{\circ}C$ and the densification with increasing addition LBT glass frist developed rapidly which was meant to be namely 90% of relative density. The sintered bodies ekhibited applicable dielectric properties, namely 15 for $\varepsilon$$_{r}$,, 10000 GHz for Q* $f_{0}$. The results suggest that the composites have good potential as a new candidate for LTCC materials.

A Study on Folkcraft Processing Art and Designing Development-Especially Centerin garound Plant-Stalk Works (한국민속공예제품 가공기술 및 디자인 개발에 관한 제고방식-초경공예제품을 중심으로)

  • 남상교
    • Archives of design research
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    • v.2 no.1
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    • pp.13-41
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    • 1989
  • The raw materials for plant-stalk-folkcrafts are cultivated in the whole country. Most Korean farmers, to increase their income, have produced mats and containers with various plants as a side line from very long ago. At first, they began from the instruments of life and then made folkart and at last get to manu\ulcornerfacturing of industrial folk craft. The folkcrafts, made of plant-stalk, which could nor conform to changing society, are partly declined and partly handed down as the traditions. The social change today, however, makes living conditions more speedy and multisided, accordingly the characteristics of demand also become in\ulcornerdividual and various. While the demend is various like this, suppliers cannot answer demendants' requirements, and consequently, the demand and profit cannot be increased. According to this, the purpose of this study is set up to give an answer to the situation that is at the traditional standstill, through an examination of the motives. I. The crafts of plant-stalk are made only in an organized relationship between agriculture, industry and art as it is compounded art of gathering raw material, manufacturing, producing, improv\ulcornering design and production conditions. It may be possible that a farmer gathers material and weaves it manually but in others, it is im\ulcornerpossible to refine, bleach and dye because the process requires a professional industrial treatment. It is impossible to make art works to a farmer as every farner does not always have aesthetic sense. Though a farmer or producer has these all abilities, it is not desirable to him from economical view. 2. The development or improvement is essential in many sides but the most important thing seems to he in design. According to reports, it is, howevt!r, fact that the crafts improved in design of existing works have more expanded the sales than newly developed works. Therefore, ir appears advisable to improve designs of existing things positively as they have merit of occupying a position already, but on the other hand, new crafts have to be also developed and the producer should grasp the proper time. 3. Building up an industrial complex to improve design with collecting the producing districts for this works scattered allover the country is very desirable for speedy communication, intensive educa\ulcorner tion or training, and effective guidance. 4. In producing for export abroad, before everything, must know the life environment, custom! and manners, main thought of the country, and then produce according to these. S. The crafts of plant-stalk are the fIrst industry in present but in the futher it should change intc second or third industry. 6. A synethetic organization for supporting side line should be established for effectiveness, and experts have to be secured and also the educational-industrial complex and activation of study should be preceded.

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