• 한국치위생학회지
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• 제10권3호
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• pp.503-512
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• 2010

Objectives : In this study, in order to provide basic data for more efficient and systematic clinical practice training by recognizing the need of effective and standardized operation of clinical practice accomplished in clinical fields belonging to the curriculum of dental hygiene department, grasping, investigating, and analyzing satisfaction degree of the clinical practice through student's frequency of observation practice and performance practice. Methods : A survey was conducted against 208 students in the 3rd grade of 4 dental hygiene departments located in Jeonbuk province. Results : As results, it was found that for the observation practice frequency according to clinical practice term by universities, the basic clinical practice was higher in A, B, and D university and that the correction and practice was higher in D university. For the performance practice frequency, it was found that basic care practice was higher in B and D university, oral medicine practice, preventive dentistry practice, and periodontal practice were higher in A and C university, pediatric dentistry practice was higher in B and C university, prosthetic dentistry practice was higher in A, B, and C university, and oral surgery practice was higher in B university. It was identified that satisfaction was higher in the basic care practice, the preventive dentistry practice, and the periodontal practice in the range of clinical practice, and the A and C university receiving higher score in the performance practice frequency got higher score in the oral medicine practice, the preventive dentistry practice, and the periodontal practice. Conclusions : As the basic care practice items in the clinical practice area which got relatively higher score in observation practice, performance practice, and satisfaction degree of the dental hygiene trainee are basic and essential works that they will perform the most frequently, it is considered that integrated clinical practice training including the intramural practice course is required.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1283-1285
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• 1996

This paper proposed frequency estimation the method of distorted sinusoidal signals by harmoics. An approximate estimation based on FFT and the accurate basic frequency was estimated by proposed method with Fourer Series, and the harmonics were estimated by the basic frequency. The sinusoidal signals is extracted by filter banks based on the estimated hamonics. The rate of basic and hamonics power is estimated by the extracted sinusoidal signals and we developed their algorithm and programs.

• ETRI Journal
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• 제27권5호
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• pp.643-646
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• 2005

This letter proposes a band-pass filter (BPF) with two transmission zeros based on a combination of parallel coupling and end coupling of half-wave transmission lines. The fabricated BPF exhibited a narrow bandwidth and two transmission zeros near the pass-band due to the end-coupled and shielding waveguide. At the center operation frequency of 60 GHz, the 20 dB bandwidth of the BPF is 1.0 GHz, which is almost 2% of the center operation frequency, and the insertion loss is 3.12 dB. Two transmission zeros reach approximately 40 dB at 58.5 and 62.5 GHz. The simulation results almost agree with the measured results.

• 산업공학
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• 제18권3호
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• pp.333-342
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• 2005

In this paper, we propose an efficient forecasting methodology of the mid and long-term frequency demand in Korea. The methodology consists of the following three steps: classification of basic service group, calculation of effective traffic, and frequency forecasting. Based on the previous studies, we classify the services into wide area mobile, short range radio, fixed wireless access and digital video broadcasting in the step of the classification of basic service group. For the calculation of effective traffic, we use the measures of erlang and bps. The step of the calculation of effective traffic classifies the user and basic application, and evaluates the effective traffic. Finally, in the step of frequency forecasting, different methodology will be proposed for each service group and its applications are presented.

• ETRI Journal
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• 제27권2호
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• pp.133-139
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• 2005

A monolithic microwave integrated circuit (MMIC) chip set consisting of a power amplifier, a driver amplifier, and a frequency doubler has been developed for automotive radar systems at 77 GHz. The chip set was fabricated using a 0.15 ${\mu}$ gate-length InGaAs/InAlAs/GaAs metamorphic high electron mobility transistor (mHEMT) process based on a 4-inch substrate. The power amplifier demonstrated a measured small signal gain of over 20 dB from 76 to 77 GHz with 15.5 dBm output power. The chip size is 2mm${\times}$ 2mm. The driver amplifier exhibited a gain of 23 dB over a 76 to 77 GHz band with an output power of 13 dBm. The chip size is 2.1mm${\times}$ 2mm. The frequency doubler achieved an output power of -6 dBm at 76.5 GHz with a conversion gain of -16 dB for an input power of 10 dBm and a 38.25 GHz input frequency. The chip size is 1.2mm ${\times}$ 1.2mm. This MMIC chip set is suitable for the 77 GHz automotive radar systems and related applications in a W-band.

• ETRI Journal
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• 제27권3호
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• pp.304-311
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• 2005

We report on the fabrication of an AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) using a dielectric-defined process. This process was utilized to fabricate $0.12\;{\mu}m\;{\times}\;100 {\mu}m$ T-gate PHEMTs. A two-step etch process was performed to define the gate footprint in the $SiN_x$. The $SiN_x$ was etched either by dry etching alone or using a combination of wet and dry etching. The gate recessing was done in three steps: a wet etching for removal of the damaged surface layer, a dry etching for the narrow recess, and wet etching. A structure for the top of the T-gate consisting of a wide head part and a narrow lower layer part has been employed, taking advantage of the large cross-sectional area of the gate and its mechanically stable structure. From s-parameter data of up to 50 GHz, an extrapolated cut-off frequency of as high as 104 GHz was obtained. When comparing sample C (combination of wet and dry etching for the $SiN_x$) with sample A (dry etching for the $SiN_x$), we observed an 62.5% increase of the cut-off frequency. This is believed to be due to considerable decreases of the gate-source and gate-drain capacitances. This improvement in RF performance can be understood in terms of the decrease in parasitic capacitances, which is due to the use of the dielectric and the gate recess etching method.

• ETRI Journal
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• 제27권1호
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• pp.75-80
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• 2005

This paper addresses a fully-integrated low phase noise X-band oscillator fabricated using a carbon-doped InGaP heterojunction bipolar transistor (HBT) GaAs process with a cutoff frequency of 53.2 GHz and maximum oscillation frequency of 70 GHz. The oscillator circuit consists of a negative resistance generating circuit with a base inductor, a resonating emitter circuit with a microstrip line, and a buffering resistive collector circuit with a tuning diode. The oscillator exhibits 4.33 dBm output power and achieves -127.8 dBc/Hz phase noise at 100 kHz away from a 10.39 GHz oscillating frequency, which benchmarks the lowest reported phase noise achieved for a monolithic X-band oscillator. The oscillator draws a 36 mA current from a 6.19 V supply with 47.1 MHz of frequency tuning range using a 4 V change. It occupies a $0.8mm{\times}0.8mm$ die area.

• Coupled systems mechanics
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• 제8권1호
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• pp.55-70
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• 2019

This investigation is focused on the variations in transversely isotropic thick circular plate due to time harmonic thermomechanical sources. The homogeneous thick circular plate in presence and absence of energy dissipation and two temperatures has been considered. Hankel transform is used for solving field equations. The analytical expressions of conductive temperature, displacement components, and stress components are computed in the transformed domain. The effects of frequency at different values are represented graphically. Some specific cases are also figured out from the current research.

• 디지털융복합연구
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• 제16권12호
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• pp.541-553
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• 2018

본 연구는 간호 간병통합서비스 병동과 일반병동 간호사를 대상으로 기본간호술의 수행 빈도 및 중요성 인식에 대한 차이점을 분석하여 간호 간병통합서비스 병동을 효율적으로 운영하는데 기초자료로 활용하기 위한 비교 조사연구이다. 연구대상자는 간호 간병통합서비스 병동 99명, 일반병동 90명 총 189명이며, 자료수집은 2018년 2.1-2.28일까지 였다. 자료분석은 t-test, One-way ANOVA, Pearson's correlation coefficient, Scheffe를 사용하였다. 연구결과 기본간호술 수행 빈도는 일반병동이 2.43회로 더 높았고, 개인위생, 영양 및 배설, 활동과 운동, 입 퇴원 및 이동에서 유의한 차이가 나타났다. 기본간호술에 대한 중요성 인식은 두 집단 모두 높게 나타났으나 간호 간병통합서비스 병동이 4.24점으로 조금 더 높았고, 개인위생, 활동과 운동, 입 퇴원 및 이동에서 유의한 차이가 있었다. 그러나 기본간호술의 중요성 인식에 비해 수행 빈도는 낮게 나타나고 있어 수행 빈도를 증가시킬 수 있는 방안이 필요하다고 사료된다. 이상의 연구결과를 근거로 간호 간병통합서비스 병동의 올바른 정착을 위해 간호사들이 전인간호 서비스를 제공할 수 있도록 적정한 간호인력 배치와 간호업무 수가개발에 대한 연구를 반복적으로 수행해 볼 필요가 있겠다.

• ETRI Journal
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• 제27권5호
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• pp.569-578
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• 2005

The purpose of this paper is to describe the implementation of monolithically matching circuits, interface circuits, and RF core circuits to the same substrate. We designed and fabricated on-chip 1 to 6 GHz up-conversion and 1 to 8 GHz down-conversion mixers using a 0.8 mm SiGe hetero-junction bipolar transistor (HBT) process technology. To fabricate a SiGe HBT, we used a reduced pressure chemical vapor deposition (RPCVD) system to grow a base epitaxial layer, and we adopted local oxidation of silicon (LOCOS) isolation to separate the device terminals. An up-conversion mixer was implemented on-chip using an intermediate frequency (IF) matching circuit, local oscillator (LO)/radio frequency (RF) wideband matching circuits, LO/IF input balun circuits, and an RF output balun circuit. The measured results of the fabricated up-conversion mixer show a positive power conversion gain from 1 to 6 GHz and a bandwidth of about 4.5 GHz. Also, the down-conversion mixer was implemented on-chip using LO/RF wideband matching circuits, LO/RF input balun circuits, and an IF output balun circuit. The measured results of the fabricated down-conversion mixer show a positive power conversion gain from 1 to 8 GHz and a bandwidth of about 4.5 GHz.