• 음성과학
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• 제9권4호
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• pp.15-25
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• 2002

It's not easy to produce very high tones during singing for not only untrained ordinary people but also even trained singers. To get high singing tones from the low tones, some trained singers used to use a distinguished singing technique, Passaggio (vocal register transition). The purpose of this study is to compare several voice parameters variation between when to sing with using the passaggio technique and to sing without using it. We selected 18 male singers (tenor 8, baritone 10), who had more than 7 years of experience and were well trained in passaggio technique. Simultaneous measurements of fundamental frequency (F0), mean flow rate (MFR), intensity (I), and subglottal pressure (Psub) were performed using the phonatory function analyzer (Nagashima). For the tenor, target tones /a/ were presented: 1) easy phonation: $B_{2}$, 2) high tone without passaggio: F$#_{3}$ 3) high tone with passaggio: F$#_{3}$. For the baritone, target tones /a/ were presented: 1) easy phonation: G$#_{3}$, 2) high tone without passaggio: D$#_{3}$, 3) high tone with passaggio: D$#_{3}$. F0 of the target tones between non-passaggio group and passaggio group was almost the same in both tenor and baritone groups. Intensity of the non-passaggio and passaggio vocalization was much louder than that of easy phonation and pasaggio was louder than non-passaggio vocalization (especially statistically significant in baritone singers). MFR of the passaggio vocalization was greater than non-passaggio vocalization in both tenor and baritone group, but statistically significant only in baritone. Psub of the passaggio vocalization was greater than that of the non-passaggio vocalization in both tenor and baritone group, but statistically not significant in tenor.

• Journal of the Korean Wood Science and Technology
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• 제34권1호
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• pp.32-39
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• 2006

본 연구는 현악기에 사용되는 현악기용 도료가 현악기의 음향성능에 미치는 영향을 조사하였다. 음향분석장치(FFT)를 이용하여 목재악기용 도료의 도막두께에 따른 음향적 성능을 평가하였다. 목재악기용으로 사용된 도료는 악기용 우레탄계 상도도료, 오일 스테인계 도료, 자외선 경화형 에폭시 도료이다. 형성된 도막의 음향적인 특성은 FFT 분석기에서 측정된 공명주파수와 댐핑값(damping factor)으로부터 동적탄성계수와 전단탄성계수를 계산하여 얻고, 밀도와의 관계와 탄성계수간의 관계를 통하여 도막의 두께에 따른 음향적인 특성을 측정하고 비교분석하여 상관관계를 조사하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.479-479
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• 2011

Flexible inverters based on complementary thin-film transistor (CTFTs) are important because they have low power consumption and other advantages over single type TFT inverters. In addition, integrated CTFTs in flexible electronic circuits on low-cost, large area and mechanically flexible substrates have potentials in various applications such as radio-frequency identification tags (RFIDs), sensors, and backplanes for flexible displays. In this work, we introduce flexible complementary inverters using pentacene and amorphous indium gallium zinc oxide (IGZO) for the p-channel and n-channel, respectively. The CTFTs were fabricated on polyimide (PI) substrate. Firstly, a thin poly-4-vinyl phenol (PVP) layer was spin coated on PI substrate to make a smooth surface with rms surface roughness of 0.3 nm, which was required to grow high quality IGZO layers. Then, Ni gate electrode was deposited on the PVP layer by e-beam evaporator. 400-nm-thick PVP and 20-nm-thick ALD Al2O3 dielectric was deposited in sequence as a double gate dielectric layer for high flexibility and low leakage current. Then, IGZO and pentacene semiconductor layers were deposited by rf sputter and thermal evaporator, respectively, using shadow masks. Finally, Al and Au source/drain electrodes of 70 nm were respectively deposited on each semiconductor layer using shadow masks by thermal evaporator. Basic electrical characteristics of individual transistors and the whole CTFTs were measured by a semiconductor parameter analyzer (HP4145B, Agilent Technologies) at room temperature in the dark. Performance of those devices then was measured under static and dynamic mechanical deformation. Effects of cyclic bending were also examined. The voltage transfer characteristics (Vout- Vin) and voltage gain (-dVout/dVin) of flexible inverter circuit were analyzed and the effects of mechanical bending will be discussed in detail.

• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.185-192
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• 2009

Purpose: The aim of this study was to examine the correlation of the subjective and the objective evaluation of edentulous ridge bone quality, and to evaluate the change of the dental implant stability in each bone density group for early healing period after implant installation. Methods: Sixty-seven implants(Osstem implant$^{(R)}$, Seoul, Korea) were included in this study. We evaluated the bone density by 2 methods. The one was the subjective method which was determined by practitioner s tactile sense, the other was the objective bone type was based on Hounsfield units. The implant stability in each bone type group was assessed by resonance frequency analyzer(Osstell mentor$^{(R)}$). Data were analyzed for the change of the implant stability, and they were compared to verify the difference of groups at the time of installation, 2, 6, 10, 14 weeks postoperatively. Spearman's correlation was used to demonstrate the correlation between the subjective and the objective evaluation of the bone density, and analysis of variance(ANOVA) was used to analyze the differences of implant stability at each time point. Results: There was no close relation between the subjective and the objective evaluation of the bone density(r=0.57). In the subjective groups, there was statistically significant difference between the type 1 and 3 at 10 weeks and between the type 2 and 3 at 14 weeks. In the objective groups, there was no statistically significant difference between the D 1, 2, 3, 4, and 5 group with regard to RFA from baseline to 14 weeks(P>0.1). Conclusions: The implant stability increased over time during the study, and it was improved with bone density proportionally after 2weeks postoperatively. It is recommended that the decision of bone density is base on Hounsfield unit for implant loading time.

• 대한한방부인과학회지
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• 제31권2호
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• pp.31-48
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• 2018

Objectives: This study was performed to observe the correlations between the results of ABR-2000 and DSOM / 3D-MAC to evaluate the feasibility of ABR-2000 as a oriental medical diagnostic criteria. Methods: We studied 547 women visiting ${\bigcirc}{\bigcirc}$ hospital from December 2012 to June 2015. The subjects were categorized in two groups, 'Hypotonia' and 'Non-Hypotonia' by the result of ABR-2000 and assessed the result of DSOM, 3D-MAC for each group. The differences of pulse wave factors by group also studied. Results: 1. There was no significant difference between two groups about the output frequency of pathogenic factors in DSOM while the result showed the higher correlation in Hypotonia group in terms of the companion tendency of pathogenic factors and syndromes formed by the combination of pathogenic factors. 2. The pulse waves of Hypotonia group were mostly slow, weak, tense and stiff than Non-Hypotonia group. Conclusions: 1. In Hypotonia group, yin deficiency (陰虛) factor was frequently accompanied and consumption (虛損) of various organs based on the yin deficiency (陰虛) was observed. It means chronic and severe condition of exhaustion syndrome (虛勞). 2. The result of 3D-MAC also means pathological feature of yin syndrome (陰 證) and consumption (虛損). Besides, lower scores of Body Surface Area (BSA), body weight, and Body Mass Index (BMI) were associated with body weakness (體瘦), a symptom of exhaustion syndrome (虛勞).

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권6호
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• pp.255-261
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• 2005

Recently, the RF inductive discharge or inductively coupled plasma continues to attract growing attention as an effective plasma source in many industrial applications, the best known of which are plasma processing and lighting technology. To the point of lighting sources, the ring-shaped electrodeless fluorescent lamps utilizing an inductively coupled plasma have been objects of interest and research during the last decades, mainly because of their potential for extremely long life, high lamp efficacies, rapid power switching response. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250 kHz and some specific conditions. The electromagnetic field in the ferrite core was shown to be high and symmetric. An LS-100 luminance meter and a Darsa-2000 spectrum analyzer were used in the experiment. According to data on the lamp tested using high magnetic field ferrite, the optical and thermal wave fields were shown to be high around the ring-shaped electrodeless fluorescent lamp. The optical or light field was high at the center of the bulb rather than around the ferrite core. The light conditions of the bulb were assumed to be complex, depending on the condition of the filler gas, the volume of the bulb, and the frequency of the inverter. Our results have shown coupling between the gas plasma and the field of the light emitted to be nonlinear.

• Journal of Community Nutrition
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• 제1권2호
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• pp.125-132
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• 1999

This study investigated the differences in dietary intake, age, body mass index(BMI), marital status and education of 1,585 Korean healthy males among current smokers, ex-smokers and non-smokers. Dietary intake was determined by a food frequency questionnaire at the Samsung Medical Center in Seoul, Korea. A bioelectric impedance analyzer measured height, body weight and BMI. This study identified 50% of the study group as current smokers and 30% as ex-smokers and 20% as non-smokers. The mean body mass index was 23.7kg/㎡ and did not differ significantly among the three groups. THe current smokers were younger(44.9 years old) and contained a lower percentage(58.5%) of college graduate than that of ex-smokers or non-smokers. The percentage of non-consumers of meat, eggs, beans and bean products was higher in non-smokers than that of ex-smokers or current smokers. Smoking was to a significant degree positively related to the amount of coffee and alcoholic beverages consumed and negatively related to the amount of milk and milk products and fruits consumed. The intake of eggs, milk and milk products, fruit, coffee, sweets, fats and oils were significantly different among the three groups. after adjusting for age, education level, marital status, and alcohol consumption. There was a strong positive relationship between smoking intensity and the intake of coffee and alcoholic beverages(p<0.0005), and an inverse relationship between smoking intensity and fruit, milk and milk product intake(p<0.005). The current smokers were characterized by a higher intake of total energy and cholesterol, and a lower intake of dietary fibers, ${\beta}$-carotine and folate than those of non-smokers or ex-smokers. The nutrient intake of ex-smokers was moderate and highest in ${\beta}$-carotine and folate, which suggested that ex-smokers were trying to change their life style.

• 조명전기설비학회논문지
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• 제15권4호
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• pp.43-50
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• 2001

본 논문은 구대구전극 사이에 고체절연체와 화염을 배치하여 방전시 절연체표면에서 발생되는 연면방전광과 화염의 변화를 CCD(Charged Coupled Device) 카메라로 관측하였으며, 방전시 발생되는 방사전자파는 스펙트럼 분석기와 바이코니칼 안테나를 이용하여 측정하였다. 인가전압 증가에 따른 고체절연체 표면에서 발생되는 연면 방전광은 커졌으며, 화염의 크기는 작아지는 것을 확인하였다. 또한 절연체표면 오염시와 화염시에는 전압강하에 의한 전압왜곡현상이 나타났다. 방사전자파의 전계세기는 절연체표면 무오염시에는 오염시보다 10∼17(dBuV/m), 절연체표면 오염시와 화염시에는 5∼9[dBuV/m]정도 높게 나타났다.

• 한국자기학회지
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• 제24권2호
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• pp.56-59
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• 2014

$Ba_2CoZnFe_{12}O_{22}$ 시료를 습식분쇄로 이용한 직접 합성법을 사용하였으며, 소결 조건의 변화에 따른 시료 제조후, x-선 회절기(XRD), 진동시료형 자화율측정기(VSM), 회로망 분석기, 그리고 뫼스바우어 분광기 측정을 이용하여 결정학적 및 자기적 특성을 연구하였다. X-선 회절 실험을 통해 Y-type hexaferrite가 주상임을 알 수 있었고, 소결 온도가 증가할수록 밀도가 증가하였다. 상온에서 10 kOe까지의 자화이력곡선 측정 결과, 포화 자화 값는 모든 시료가 약 33 emu/g으로 비슷한 값이 나왔으며, 보자력은 소결 온도가 증가할수록 감소하였다. 회로망 분석기를 통해 100 MHz부터 4 GHz까지 투자율과 유전율을 측정하였다. 그 결과, 소결 온도가 증가할수록 투자율과 tan ${\delta}_{\mu}$는 감소하였다.

• 한국추진공학회지
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• 제5권4호
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• pp.31-39
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• 2001

복합재료로 제작이 되는 수송기계용 추진축은 진동, 소음, 중량 등을 감소시킬 수 있는 장점을 가진다. 본 연구에서는 유한요소법을 이용하여 카본/에폭시 복합재료로 구성된 추진축을 설계하였으며 필라멘트 와인딩 방법을 사용하여 시험용 시편을 제작하였다. 유한요소법을 이용한 추진축의 설계 방법의 정확성을 확인하고자 FFT 해석기와 충격해머를 이용한 고유진동수 측정시험과 임계회전속도 측정 실험 장비를 이용한 임계회전속도 측정시험을 수행하였다. 해석결과와 시험결과를 비교하였을 때 오차율은 3.4%이하로 해석결과의 신뢰성을 확인하였다. 이러한 FEM 설계방법을 이용하여 추진 축의 진동 및 강도특성에 영향을 미치는 요인들에 대한 연구를 수행하였다 여러 요인들 중 중량의 증가 없이 고유진동수 변화에 가장 큰 영향을 미치는 것은 와인딩 각도임을 확인하였다.