• 한국방사선학회논문지
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• 제13권5호
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• pp.683-689
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• 2019

소아의 선천적 심장질환 진단을 위해 High Pitch Mode를 사용하여 획득한 소아 심장 CT 영상과 Wide Coverage Volume Axial Mode를 사용하여 획득한 소아 심장 CT 영상으로부터 환자의 피폭선량과 각 영상의 화질을 비교 및 분석하여 Wide Coverage Volume Axial Mode의 유용성을 평가해보고자 한다. 소아 심장 CT 검사 시 High Pitch Mode와 Wide Coverage Volume Axial Mode를 각각 50명 총 100명의 환자를 대상으로 시행하였으며, 각 프로토콜로부터 얻은 영상을 이용하여 환자의 피폭선량을 비교하였다. 각 영상에 ROI를 설정해 SNR과 CNR을 산출하여 영상의 화질을 비교하였다. High Pitch Mode에 비해 Wide Coverage Volume Axial Mode를 사용하여 검사하였을 때 환자의 피폭선량이 13.07% 감소하였고, SNR과 CNR이 향상되었다. Wide Coverage Volume Axial Mode는 고속 회전 스캐너를 이용하여 조사시간을 줄이고, 저선량 기술인 ASi R-V를 통해 High Pitch Mode를 사용했을 때보다 환자의 피폭선량이 감소하고 영상의 화질 또한 향상되는 유용한 검사라 할 수 있다.

• 한국방사선학회논문지
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• 제15권4호
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• pp.437-444
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• 2021

두경부 CT 검사시 팬텀을 이용하여 Helical mode, High Pitch Mode, Volume Axial Mode 사용하여 획득한 CT 영상으로부터 환자의 피폭선량과 각 영상의 화질을 비교 및 분석하여 Volume Axial Mode의 유용성을 평가해보고자 한다. 두경부 CT 검사 시 각 mode에 따른 70 kVp, 80 kVp, 100 kVp 관전압에 따라 검사를 시행하였다. 사용 장비로는 GE사의 Revolution(GE Healthcare, Wisconsin USA) 모델과 iMED X-ray Phantom을 이용하였다. 검사 Mode에따른 kVp별로 얻어진 영상을 이용하여 팬텀의 피폭선량을 비교하였으며, 각 영상에 ROI를 설정해 신호대 잡음비와 대조도대 잡음비를 산출하여 영상의 화질을 비교하였다. Volume Axial Mode를 사용하여 검사하였을 때 팬텀의 피폭선량이 Helical에 비해 17.12% 낮게, High Pitch에 비해 5.35% 낮게 측정되었고, 신호대 잡음비와 대조도대 잡음비가 향상되었다. Volume Axial Mode는 고속 회전 스캐너를 이용하여 테이블의 이동이 없이 조사시간을 줄이고, High Pitch Mode와 Helical Mode를 사용했을 때 보다 팬텀의 0.28초의 단시간에 영상을 획득하여 피폭선량이 감소하고 영상의 화질 또한 향상되는 유용한 검사라 할 수 있다. 또, 몸이 불편한 환자의 촬영이나 긴급환자의 CT 촬영에 있어서 Volume Axial Mode의 빠른 검사시간은 최대의 장점이라고 볼 수 있다.

• 대한간호학회지
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• 제43권2호
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• pp.185-193
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• 2013

Purpose: Simulation-based learning has become a powerful method to improve the quality of care and help students meet the challenges of increasingly complex clinical practice settings. The purpose of this study was to identify the learning effects using high-fidelity SimMan and multi-mode simulation. Methods: Participants in this study were 38 students who were enrolled in an intensive course for a major in nursing at R college. Collected data were analyzed using Chi-square, t-test, and independent t-test with the SPSS 18.0 for Windows Program. Results: There were no statistically significant differences in learning effects between high-fidelity SimMan and multi-mode simulation group. However, skills in clinical performance in the high-fidelity SimMan group were higher than in the multi-mode group (p=.014), communication in clinical performance in multi-mode simulation group was higher than in the high-fidelity SimMan group (p<.001). Conclusion: Multi-mode simulation with a standardized patient is an effective learning method in many ways compared to a high-fidelity simulator. These results suggest that multi-mode simulation be offered to students in nursing colleges which cannot afford to purchase a high-fidelity simulator, or offered as an alternative.

• 대한소아치과학회지
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• 제46권1호
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• pp.57-63
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• 2019

이 연구의 목적은 고출력 발광 다이오드 광중합기의 Xtra Power 및 High Power mode의 짧은 중합시간이 레진 치면열구전색제의 중합에 충분한지를 확인하는 것이다. 금속 주형을 이용해 시편을 제작하여 미세경도를 측정하였으며, 기존의 발광 다이오드 광중합기로 중합한 시편의 미세경도와 비교하였다. 그 결과, High Power mode로 8초, Xtra Power mode로 3초 중합한 filled sealant와 High Power mode로 8초, 12초, Xtra Power mode로 6초 중합한 unfilled sealant의 상면과 하면 모두에서 대조군보다 유의하게 낮은 미세경도를 나타냈다(p = 0.000). 이 연구를 통하여 중합 시간과 전색제의 종류를 고려한 특정 조건에서 고출력 발광 다이오드 광중합기의 Xtra Power 및 High Power mode의 짧은 중합시간이 치면열구전색제를 적절히 중합하기에 충분하지 않음을 알 수 있었다.

• 대한기계학회논문집B
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• 제22권4호
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• pp.450-467
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• 1998

The characteristics of the unstable impinging circular jet is investigated based on the frequency characteristics and the sound field of the impinging-tones. Two symmetric modes S1 and S2, associated with low frequency and high frequency respectively, and one helical mode H have been observed. At low speed the S2 mode is dominant and switched by the S1 mode as the speed increases. When the jet speed is high the S1 mode is very active over the impinging distance from half the nozzle diameter to its ten times, while the S2 mode occurs at shorter distance corresponding to stage 2 and 3. The helical mode H seems unstable, likely to be influenced much by the experimental environment, and occurs at relatively high speed with almost the same frequency characteristics as the S2 mode. By estimating the convection speed of the unstable jet, it is found that the ratio of the convection speed to the jet speed decreases with both Strouhal number and Reynolds number and the speed of S2 mode is faster than the Si mode. When the present experimental results are compared with the previous investigations performed for the hole tone and the impinging tone with a small plate, the S1 mode is found to be associated with the ring vortex of large diameter with low speed, but the S2 mode with the vortex of small diameter with high speed. In addition, the frequency is found to be influenced by the nozzle configuration but the characteristics is almost the same. From the impinging distance and frequency range, it can be deduced that S1 mode is related with the jet column mode and S2 mode with the shear mode.

• 대한물리치료과학회지
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• 제2권2호
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• pp.465-479
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• 1995

We randomly assigned 61 healthy subjects(male 14, female 47) to compare the experimental pain threshold and skin temperature between high mode TENS and burst mode TENS. In this study, 61 subjects were divided into three groups ; high mode TENS(n=20), burst mode TENS (n=20), and control group(n=21). Experimental pain thresholds and skin temperatures were measured before, immediately after cessation of stimulation, and at 30 minutes post stimulation. Stimulation was applied to the dorsal surface of the forearm(L14, LI10). Pain thresholds were measured by chronaxie meter. Skin temperature were measured by electrical digital thermometer. The results are as follows ; 1. There were no statistical difference in the pain threshold and skin temperature at before TENS stimulation among the three groups(p>0.05). 2. The pain threshold and skin temperature in burst mode TENS group was significantly higher and longer effect than that in high mode TENS group and control group(p<0.01). 3. The pain threshold in burst mode TENS group decreased to prestimulation levels by 30 minutes poststimulation. 4. The skin temperature in burst mode TENS group decreased to prestimulation levels by 20 minutes poststimulation. 5. The skin temperature was significantly difference among three group at immediately after, and at 30 minutes poststimulation and the skin temperature in burst mode TENS group was significantely higher than that in two groups(p<0.001). 6. The increasing rate of pain threshold in high mode TENS group after immediately cassation of stimulation was 24.3%(p<0.001). 7. The increasing rate of pain threshold in burst mode TENS group after immediately cessation of stimulation was 93.5% (p<0.001).

• 말소리와 음성과학
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• 제4권3호
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• pp.119-125
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• 2012

This paper describes a new algorithm for encoding spectral shape and envelope in the generic mode of G.718 super-wide band (SWB). In the G.718 SWB coder, generic mode coding and sinusoidal enhancement are used for the quantization of modified discrete cosine transform (MDCT)-based parameters in the high frequency band. In the generic mode, the high frequency band is divided into sub-bands and for every sub-band the most similar match with the selected similarity criteria is searched from the coded and envelope normalized wideband content. In order to improve the quantization scheme in high frequency region of speech/audio signals, the modified generic mode by the improvement of the generic mode in G.718 SWB is proposed. In the proposed generic mode, perceptual vector quantization of spectral envelopes and the resolution increase for spectral copy are used. The performance of the proposed algorithm is evaluated in terms of objective quality. Experimental results show that the proposed algorithm increases the quality of sounds significantly.

• 대한기계학회논문집B
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• 제22권11호
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• pp.1582-1590
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• 1998

Combustion-driven oscillations in a surface burner have been investigated to clarify their characteristics. A model combustor is made and the oscillation frequencies are measured for various dimensions of the combustor. It is found that there are two modes of oscillations; one is the 'acoustic mode' at high frequencies, associated with the acoustic mode of the combustion system and the other is the 'combustion mode' at low frequencies around 100 Hz, associated with the instability of the flame. Acoustic mode is excited when the surface burner is placed where the phase of particle velocity leads that of acoustic pressure by $90^{\circ}$, for all the combustion conditions. Combustion mode is driven at high combustion rate by the lift of unstable flame near the lower limit of the combustible equivalence ratio. Combustion mode is greatly influenced by the inlet temperature of the premixed gas. When the inlet temperature is very high, the combustion mode does not occur.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.151-154
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• 2001

This paper propose a new active common-mode voltage damper circuit that is capable of suppressing a common-mode voltage produced in the PWM VSI. The new active common mode voltage damper is consisted of a half-bridge inverter and a common mode transformer with a blocking capacitor. Principle of the active common mode damper is as follow; by applying the compensation voltage which has the same amplitude and opposite polarity to the PWM inverter system. So, common mode voltage and high frequency leakage current can be reduced. Simulated and experimental results show that common-mode voltage damper makes contributions to reducing a high frequency leakage current and common-mode voltage.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.373-376
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• 1999

This paper propose a "common mode voltage damper" that is capable of reducing the common mode voltage produced in the PWM VSI. An push-pull circuits and high frequency leakage current damper[1] are incorporated into the "common mode voltage damper", the design method of which is presented. Effect of "common mode voltage damper" is simulated in this paper verifies the viability and effectiveness in 2.2kW induction motor drive using IGBT inverter. Simulated results show that "common mode voltage damper" makes significant contributions to reducing a high frequency leakage current.ducing a high frequency leakage current.