• 한국광학회지
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• 제13권1호
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• pp.65-69
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• 2002

불소원자(F)와 D$_2$ 기체 발열반응에 의해 레이저 이득매질인 DF 여기분자를 생성시키는 구조의 연속발진형 불화중수소 (DF)화학 레이저를 설계, 제작하고 발진 실험을 수행하였다. 불소원자는 F$_2$ 기체와 H$_2$ 기체를 연소시켜 생성시키고, 불소원자를 초음속 노즐을 통과시킨 직후에 D$_2$ 기체를 분사하여 형성된 DF 여기분자 초음속 흐름을 활성 매질로 사용하여 레이저를 발진시켰다. 본 연구에서 얻은 레이저 발진 출력은 101W이며, 최적의 유량조건에서 얻은 화학 효율은 5.12%, 비출력은 96.5 J/g이다.

• Journal of electromagnetic engineering and science
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• 제15권2호
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• pp.120-122
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• 2015

This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna (MSA) based on surface wave suppression. The back radiation of the MSA is significantly reduced by using the meandered ground plane edges and placing split-ring resonators (SRRs) in the middle of the meandered slots. By loading SRRs near the center of the meandered ground plane edges, some parts of the diffracted back-lobe power density can be reduced further. Compared to the F/B ratio of a conventional MSA with a full ground plane of the same size, an improved F/B ratio of 18 dB has been achieved experimentally for our proposed MSA.

• Restorative Dentistry and Endodontics
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• 제31권2호
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• pp.125-132
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• 2006

본 연구는 레진 블록에서 엔진구동형 Ni-Ti기구를 이용하여 근관성형 후 Buchanan plugger의 삽입 깊이에 대한 비교를 통해 임상적 상황에서 Ni-Ti 파일로 근관 성형 후 Continuous wave of condensation technique을 이용한 근관 충전시 적절한 크기의 Buchanan plugger 선택에 지침을 제공하기 위해 시행되었다. 만곡근관과 직선근관을 가진 레진 블록에서 ProTaper와 ProFile을 이용하여 근관 성형을 하였다. 성형 후 근관에 Buchanan plugger가 근관벽과 처음으로 접촉하는 부위까지 삽입한 후 그 상태에서 스캐너를 이용하여 이미지를 얻었다. 이미지 분석 프로그램을 이용해 근첨에서 plugger 첨부까지의 거리를 얻었다. 각 기구에 대한 plugger 삽입깊이에 대한 유의성을 검정하기 위해 one-way ANOVA를 시행하였고, 사후검정을 위해 Scheffe's test를 시행하였다. 본 연구의 결과 만곡되고 좁은 근관에서, ProTaper F2와 F3로 마무리 성형한 근관에서 F, FM크기의 plugger를 사용할 경우 Continuous wane of condensation technique으로 적절한 근관충전이 가능함을 시사하였다.

• 대한정형도수물리치료학회지
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• 제11권2호
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• pp.62-70
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• 2005

The determination of peripheral nerve conduction velocity is an important part to electrodiagnosis. Its value as neurophysiologic investigative procedure has been known for many years but normal value of median and ulnar motor nerve was poorly reported in Korea. To evaluate of median and ulnar motor nerve terminal latency, amplitude of CMAP(compound muscle action potential), conduction velocity and F-wave latency for obtain clinically useful reference value. 71 normal volunteers(age, 19-65 years; 142 hands) examined who has no history of peripheral neuropathy, diabetic mellitus, chronic renal failure, endocrine disorders, anti-cancer medicine, anti-tubercle medicine, alcoholism, trauma, radiculopathy. Nicolet Viking II was use for detected terminal latency, amplitude of CMAP, conduction velocity and F-wave latency of median and ulnar motor nerve. Data analysis was performed using SPSS. Descriptive analysis was used for obtain mean and standard deviation, independent t-test was used to compare between Rt and Lt side also compare between different in genders. The results are summarized as follows: 1. Median motor nerve terminal latency was right 3.00ms, left 2.99ms and there was no significantly differences between right and left side and genders. 2. Median motor nerve amplitude of CMAP was right 17.26mV, left 1750mV and there was no significantly differences between right and left side and genders. 3. Median motor nerve conduction velocity was right 57.89m/sec, left 58.03m/sec and there was no significantly differences between right and left side and genders. 4. Median motor nerve F-wave latency was right 25.74ms, left 25.59ms and there was significantly differences between genders. 5. Ulnar motor nerve terminal latency was right 2.38ms, left 2.45ms and there was significantly differences between right and left side. 6. Ulnar motor nerve amplitude of CMAP was right 15.99mV, left 16.02mV and there was no significantly differences between right and left side and genders. 7. Ulnar motor nerve conduction velocity was right 60.35m/sec, left 59.73m/sec and there was no significantly differences between right and left side and genders. 8. Ulnar motor nerve F-wave latency was right 25.53ms, left 25.57ms and there was significantly differences between genders.

• 대한방사선기술학회지:방사선기술과학
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• 제20권2호
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• pp.44-48
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• 1997

For the efficient management of the diagnostic x-ray equipment, a nation-wide inspection of hospitals was performed by an inspection institute in Taejon in the first half of 1997. Among those hospitals inspected, 28 equipments(machines) which were over 500 mA were randomly selected according to their characteristics : 7 condenser type x-ray equipments, 7 three control phase of full wave rectification of type remote control x-ray equipments, 7 single phase of full wave rectification type for general radiography equipments, and 7 single phase of full wave rectification type of R/F equipments. We obtained the following results by conducting the experiment based on the efficiency of the equipments mentioned above. 1) When the equipments are analyzed, 2 out of 7 single phase of full wave rectification type of general radiography equipments(28.6%), 3 out of 7 single phase of full wave rectification type of R/F equipments(42.9%), 5 out of 7 three phase of full wave rectification type remote of control x-ray equipments(71.4%), and 4 out of 7 condenser type of x-ray equipments(57.1%) showed suitability. It proves the superiority of the three phase of full wave rectification type of remote control x-ray equipments. 2) From the overall analysis, only about 50% of the equipments(suitability of 14 out of 28) maintain the efficient management. Therefore, maintenance management of equipments is more necessary. If the efficiency of the x-ray equipment is uniformly maintained and managed to prevent the breakdown(trouble) beforehand especially through the continuous inspection of tube voltage, tube current, exposure time, and collimator, the financial loss and exposure dose to the patient, as well as the workers engaged in radiation, can be reduced for better medical service.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.1009-1012
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• 2000

In this paper, we have designed and fabricated power PHEMT’s with an unit gate width of 80$\mu\textrm{m}$ and 4 fingers, and MIMIC power amplifiers using the PHEMT’s as well. The PHEMT’s have a 0.2$\mu\textrm{m}$ gate length and source to drain spacing of 3$\mu\textrm{m}$. The characteristics of the fabricated PHEMT’s are 4.08dB of S$\sub$21/ gain at the 35GHz and 317mS/mm of gm, and 62GHz of f$\sub$T/ and 120GHz of f$\sub$max/. The designed and fabricated MIMIC’s power amplifiers with 6 PHEMT’s and MIN capacitors were fully passivated by 1000 Α of Si$_3$N$_4$ film for higher performance and surface protects. The chips were processed using the MINT processes, and size was 3.25 ${\times}$ 1.8$\textrm{mm}^2$. The fabricated MIMIC power amplifiers have RF characteristics such as 11.25dB of S$\sub$21/ gain, 11.37dB of input return-loss and 12.69dB of output return-loss at the 34.55GHz.

• 동의생리병리학회지
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• 제26권5호
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• pp.745-752
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• 2012

This study aims to show the change of Heart Rate Variability(HRV) and Pulse wave velocity(PWV) on menstruation in women at college. Heart Rate Variability(HRV) and Pulse wave velocity(PWV) of 122 women at college were measured at their menstruation and ordinary period. SDNN, RMSSD, SDSD, HRV Index(%), stress resistance and cardiac activity were significantly higher at their menstruation than ordinary period, but Total Power and pNN50(%) were opposite. The automatic nervous system balance and physical stress were decreased in groups without dysmenorrhea than with one. PWV(E-R) and PWV(E-L) were much higher at menstruation than ordinary period. PTT(F-R) and PTT(F-L) were decreased in groups without dysmenorrhea than with severe one. We demonstrated that menstruation can effect on Heart Rate Variability and Pulse wave velocity and dysmenorrhea can cause the imbalance of autonomic nervous system.

• Structural Engineering and Mechanics
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• 제1권1호
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• pp.47-60
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• 1993

The eigen-equation of a wave traveling over repetitive structure is derived directly form the stiffness matrix formulation, in a form which can be used for the case of the cross stiffness submatrix $K_{ab}$ being singular. The weighted adjoint symplectic orthonormality relation is proved first. Then the general method of solution is derived, which can be used either to find all the eigensolutions, or to find the main eigensolutions for large scale problems.

• 화훼연구
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• 제16권3호
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• pp.211-217
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• 2008

나리 돌연변이 육종을 위한 기초자료로서 구근, 종자, 화분의 방사선 감수성을 구명하고자 하였다. 'New Wave'외 6품종의 구근은 감마선에 매우 민감하였다. 무조사구는 개화하였으나 조사구에서는 생육이 크게 지연되었으며 화서는 전혀 형성되지 않았다. 'New Wave'와 'Tiny Dino'는 125Gy 조사구에서 생존은 하였으나 생육은 저조하였다. 'New Wave'와 'Tiny Dino'를 제외한 다른 품종들은 잎의 일부 또는 전부가 고사하였다. 품종별 인편의 수분함량은 72~78%이었다. 인편으로부터 자구 형성은 무조사구에서 100%, 조사된 구에서는 'Siberia' 50Gy 처리구에서만 8.5% 일어났다. 화분의 발아율은 감마선 조사에 의해 일정한 경향을 나타내지 않았다. $F_1$ 'Augusta' 종자는 선량이 높아질수록 생존율은 급격히 떨어졌다. 자구는 무조사구에서만 형성되었으며 $LD_{50}$는 100Gy 미만이었다. 방사선 조사된 기내 $F_1$ 'Augusta'의 자구는 배양방법에 관계없이 구고와 구폭이 선량 증가와 함께 감소하였다. 신초 형성은 무조사구에서 100% 되었으나 다른 처리구에서는 15~16%로 떨어졌다.

• 한국산학기술학회논문지
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• 제18권10호
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• pp.290-298
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• 2017

본 연구는 초기 손목터널증후군으로 진단된 환자의 정중신경(median nerve)과 자신경(ulnar never)의 및 F파를 대조군과 비교 분석하여 초기 손목터널증후군의 진단에서 F파가 유용한 지표가 될 수 있는지 알아보고자 하였다. 신경전도검사 결과의 주요 지표인 말단잠복기, 말단진폭, 손바닥-손목 구간의 감각신경전도속도 및 F파 잠복기를 대조군과 t-test 검정으로 비교분석하고, 또한 주요 지표간의 상관성 분석을 위하여 상관분석을 실시하였다. 연구결과, 대조군과 초기 손목터널증후군 환자의 정중신경 말단잠복기 비교에서 두 군 간에 유의성이 높은 것으로 나타났다(p<0.001). 정중신경의 감각신경전도속도 비교에서는 대조군과 손목터널증후군 간의 유의성이 높은 것으로 관찰되었다(p<0.001). 후기반응검사인 F파 잠복기 분석에서 정중신경의 경우 대조군과 손목터널증후군간 높은 유의성(p<0.001)을 보였으나, 자신경의 경우는 차이가 없는 것으로 나타났다. 상관분석 결과는 감각신경전도속도와 말단잠복기, F파와 말단잠복기에서 모두 상관성이 있는 것으로 나타났다. 이러한 결과로, F파는 말단잠복기, 감각신경전도속도와 같이 손목터널증후군의 진단에 있어 유용한 지표가 될 수 있다고 사료된다.