• 대한후두음성언어의학회지
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• 제9권2호
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• pp.142-146
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• 1998

Background : It has been established that the fundamental frequency(Fo) of the vowels varies systemically as a function of vowel height. Specifically, high vowels have a higher Fo than low vowels. Two major explanations or hypotheses dominate contemporary accounts of fired to explain the mechanisms underlying intrinsic variation in vowel Fo, source-tract coupling hypothesis and tongue-pull hypothesis. Objectives : Total laryngectomy surgery necessiates removal of all structures between the hyoid bone and the tracheal rings. Therefore, the assumption that no direct interconnection exists between the tongue and pharyngoesophageal segment that would mediate systematic variation in vowel Fo appears quite reasonable. If tongue-pull hypothesis is correct, systemic differences in Fo between high versus low vowels produced by esophageal speakers would not Or expected. We analyzed the Fo in the vowels of esophageal voice. Materials and method : The subjects were 11 cases of laryngectomee patients with fluent esophageal voice. The five essential vowels were recorded and analyzed with computer speech analysis system(Computerized Speech Lab). The Fo was measured using acoustic waveform, automatically and manually, and narrow band spectral analysis. Results : The results of this study reveal that intrinsic variation in vowel Fo is clearly evident in esophageal speech. By analysis using acoustic waveform automatically, the signals were too irregular to measure the Fo precisely. So the data from automatic analysis of acoustic waveform is not logical. But the Fo by measuring with manually calculated acoustic waveform or narrowband spectral analysis resulted in acceptable results. These results were interpreted to support neither the source-tract coupling nor the tongue-pull hypotheses and led us to offer an alternative explanation to account for intrinsic variation of Fo.

• International journal of advanced smart convergence
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• 제9권1호
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• pp.63-69
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• 2020

The rapid development in modern industrialization pollutant the water and atmospheric air across the globe that have a major impact on the human and livings health. In worldwide, every country government increasing the importance to improve the outdoor air pollution monitoring and control to provide quality of life and prevent the citizens and livings life from hazard disease. We proposed the environmental dust level detection method for outdoor facilities using sensor fusion technology to measure precise micro-dust level and monitor in realtime. In this proposed approach use the camera sensor and commercial dust level sensor data to predict the micro-dust level with data fusion method. The camera sensor based dust level detection uses the optical flow based machine learning method to detect the dust level and then fused with commercial dust level sensor data to predict the precise micro-dust level of the outdoor facilities and send the dust level informations to the outdoor air pollution monitoring system. The proposed method implemented on raspberry pi based open-source hardware with Internet-of-Things (IoT) framework and evaluated the performance of the system in realtime. The experimental results confirm that the proposed micro-dust level detection is precise and reliable in sensing the air dust and pollution, which helps to indicate the change in the air pollution more precisely than the commercial sensor based method in some extent.

• 터널과지하공간
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• 제27권1호
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• pp.58-68
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• 2017

광학기술의 발달로 LIDAR장비들은 사양이 급속도로 발전하여 현재 암반의 정보들을 효과적으로 얻어 낼 정도의 정밀성과 정확성을 확보하고 있고 현장 활용이 용이하도록 경량화 및 보급화가 이루어진 상황이다. 본 연구에서는 넓은 영역의 암반 사면을 대상으로 LIDAR를 이용하여 절리면 거칠기를 측정하는 방법의 적용성에 대하여 고찰해 보았다. 점 간격에 따른 네 가지 거칠기 변수와 JRC와의 상관관계를 회귀 분석하였으며 LIDAR를 이용하여 삼차원 삼각망을 구성하고 면 구조인 패치를 검출하여 암반 사면 절리면의 거칠기를 산정하는 연구를 수행하였다. 실내시험을 통하여 네 가지 거칠기 파라미터와 JRC의 회귀식을 제시하였으며, 네 가지 파라미터 모두 점 간격이 커질수록 거칠기 파라미터 값의 감소를 보이며, 더 큰 거칠기를 갖는 시료에서 더 큰 감소폭을 보임을 알 수 있었다. 현장에서 LIDAR 스캔을 통하여 $R_s$ 파라미터와 점 간격을 고려한 거칠기를 산정하는 알고리즘을 제시하였으며 실제 거칠기 측정 결과보다 다소 과대평가 되는 경향이 있음을 확인하였다.

• Mass Spectrometry Letters
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• 제3권3호
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• pp.68-73
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• 2012

Fat malabsorption is an important cause of poor growth in infancy and childhood. Steatorrhea tests have been developed using various methods. Traditional measurements of stool fat, however, require large samples and it often takes as a week to complete the analysis. In this paper, a liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) method was developed for simultaneous quantitative analysis of triacylglycerols, triolein, diolein and monoolein, in mouse feces. Moreover, the procedure was rapid, simple as well as compatible with LC-ESI/MS. Chloroform-isopropyl alcohol solution was used for fat-soluble sample extraction. After centrifugation and filtration, an analytical solution was prepared. Triolein, diolein and monoolein were separated using non-aqueous reversed-phase column with the mobile phase consisting of A (methanol) and B (acetone-isopropyl alcohol). The precision (% CV) and accuracy (% bias) of the assay were 3.8-14.7% and 85.2-114.9%, respectively. This method has been successfully applied to simultaneous determination of triolein, diolein and monoolein in feces from 30 mice. This method can therefore be applied to measure triacylglycerols in mouse feces accurately and precisely by LC-ESI/MS, thereby helping to predictive biomarker in fat malabsorption and diagnostic research.

• 말소리와 음성과학
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• 제11권4호
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• pp.9-18
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• 2019

본고는 한국인 피험자를 대상으로 지각 실험을 진행하여 화자의 실제 연령(Chronological age)과 지각 연령(Perceived age) 간의 상관관계를 살피고, 한국인 피험자가 얼마나 정확하게 익명의 화자의 연령을 지각할 수 있는지를 밝히고자 한다. 또한, 이러한 연령 지각에 음성적 단서가 되는 음높이와 발화 속도와 지각 연령 간의 영향 관계를 검토하고자 한다. 이를 위해, 성인 80명을 대상으로 3가지 과제로 구성된 지각 실험을 진행하였다. 실험 자극은 표준어 화자 40명에게서 추출되었으며, 자유 발화, 낭독 발화, 모음 연장 발성으로 구성되었다. 각 실험은 10초 내외의 음성을 듣고 연령을 구체적인 숫자로 답하는 방식으로 진행되었다. 분석 결과, 한국인 피험자들은 상당히 높은 판단 정확도를 보였으며, 모음 연장 발성을 들었을 때보다 자유 발화와 낭독 발화를 들었을 때 화자의 연령을 더욱 정확하게 짐작하였다. 이러한 결과는 음성이 포함하고 있는 정보량의 차이에 기인한 것으로 보인다. 또한, 음성 분석을 수행한 결과 피험자들은 화자의 음높이와 발화 속도를 참고하여 화자의 연령을 추정하는 것으로 나타났으며, 음높이보다는 발화 속도가 연령 지각에 더 적극적으로 기여한 것으로 나타났다.

• 한국전자파학회논문지
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• 제29권4호
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• pp.308-315
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• 2018

본 논문에서는 두 표적 간의 거리차를 정밀하게 계측할 수 있는 S-band 고 분해능 레이다 개발을 위한 시스템 기본 설계 및 구현 결과를 제시한다. 3.5 GHz LFM(Linear Frequency Modulation) 레이다 기본 설계를 위하여 제안하는 시스템 요구조건은 거리 분해능 1 m, 최대 계측 거리 2 km이며 레이다 방정식을 통해 각 모듈의 사양을 결정하였다. 최종적으로 150 MHz 대역폭, 송신 출력 43 dBm 전력 증폭기, 이득 26 dBi 안테나, 잡음 지수 8 dB 이하, RCS $1m^2$일 때, 표적과 레이다의 최대거리 2 km 기준 SNR이 30 dB 이상이 나올 수 있음을 확인할 수 있었다. 시뮬레이션 결과를 토대로 하드웨어 설계를 하였으며, SDR(Software Defined Radar) 장비를 이용한 LFM 레이다 설계 이론과 방법 그리고 야외 시험 결과를 보여주고 요구조건을 만족하는 레이다 시스템 설계가 가능함을 입증하였다.

• 대한치과보철학회지
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• 제25권1호
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• pp.17-40
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• 1987

The purpose of this study was to clarify the effect of clasp design on abutment tooth adjacent to a distal extension base under the influence by the location of functional loading. The RPI clasp, the Akers clasp and the combination clasp were selected for evaluation. Tests were performed at 10Kg, 20Kg, 30Kg loads on the buccal, central, lingual, mesial and distal positions of loading platform of each mandibular distal extension partial denture. The laser reflexion method was used for three dimensional measurement of abutment movement, which is possible to measure precisely without contact. The movement in the mesiodistal(X), buccolingual(Y), and occlusoapical(Z) directions and the rotational movement(R) were measured, and in addition, the total movement (SV) as expressed by the three dimensional summation vector independent of direction was calculated. The data were analyzed using Student t-test, p<.05. The following results were obtained from this study; 1. Clasp design did not generally affect the direction of abutment tooth movement except the movement in an undesirable occlusal direction in case of the Akers clasp and the combination clasp. 2. The greater the load on the prosthesis, the greater was the abutment tooth movement, and the direction of abutment tooth movement was affected by positional loading. 3. Each prosthesis was dislodged from the test base under the small amount of load in the distal load position, and the buccal loading showed the greatest abutment tooth movement under the maximum load. 4. RPI clasp was evaluated as the most favorable design.

• 한국측량학회지
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• 제29권6호
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• pp.561-568
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• 2011

본 연구는 근거리 사진측량기법을 이용하여 사면모형 진동실험시 사면모형 지표부 및 내부에 발생하는 변위와 사면파괴시 형상을 측정하는 것을 목적으로 한다. 사면모형 챔버와 사면모형에 원형타겟과 구형타겟을 설치하고 일정 시간간격으로 지진파를 가하였으며 사면모형이 파괴될 때까지 각 단계별로 사진을 촬영을 실시하였다. 촬영된 사진은 영상처리기법을 이용하여 타겟의 중심점을 자동으로 추출하였으며 표정 및 광속조정을 통해 타겟의 3차원 좌표값을 계산하였다. 실험결과 각 실험단계에서 변위량을 정밀하게 측정할 수 있었으며 타겟의 거동 및 파괴형상을 3차원으로 표시함으로써 사면 안정성 평가를 위한 모형실험시 기초자료로 활용할 수 있었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.54-54
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• 2018

To optimize the deposition parameters of diamond films, the temperature, pressure, and distance between the filament and the susceptor need to be considered. However, it is difficult to precisely measure and predict the filament and susceptor temperature in relation to the applied power in the hot filament chemical vapor deposition (HFCVD) system. In this study the temperature distribution inside the system was numerically calculated for the applied powers of 12, 14, 16 and 18 kW. The applied power needed to achieve the appropriate temperature at a constant pressure and other conditions was deduced, and applied to actual experimental depositions. The numerical simulation was conducted using the commercial computational fluent dynamics software, ANSYS-FLUENT. To account for radiative heat-transfer in the HFCVD reactor, the discrete ordinate (DO) model was used. The temperatures of the filament surface and the susceptor at different power levels were predicted to be 2512 ~ 2802 K, and 1076 ~ 1198 K, respectively. Based on the numerical calculations, experiments were performed. The simulated temperatures for the filament surface were in good agreement with experimental temperatures measured using a 2-color pyrometer. The results showed that the highest deposition rate and the lowest deposition of non-diamond was obtained at a power of 16 kW.

• 대한지구과학교육학회지
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• 제5권1호
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• pp.88-94
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• 2012

This study was created to resolve the problems embedded in the formal measuring experiments to determine the earth's size in the current curriculum, to develop an updated measuring experiment to determine the earth's size and to establish its effect. For this study, pre-service elementary teachers, who had attempted the experiment of measuring the size of the earth when they were in middle school, performed the experiments in the existing national curriculum, and their responses, collected through in-depth interviews, were examined. To begin with, the pre-service elementary teachers conducted the experiment of measuring the earth size and they recorded the problems while performing it. At the end, an in-depth interview was administered. Based on the problems, an updated measuring experiment to determine the earth's size was suggested to be applied to the same contents and be analyzed through the in-depth interviews. Common themes which were mutually categorized and analyzed by the two researchers were obtained based on the records produced while conducting the experiment and the in-depth interview data. The teachers mentioned that the experiments for measuring the size of the earth in the current curriculum gave rise to difficulties in measuring precisely the angles between the string and the post. Also, there has been a scientific contradiction that solar altitudes were increased in a high latitude region, instead of decreased. For this reason, an alternative method has been developed to measure the earth's size using the distance and the solar altitude difference of two places. The teachers all agreed that by using the updated measuring experiment, they can acquire more precise measurements and it is easier, faster and consequently more effective than the existing methods. Through the results of this study, I suggest that the newly developed experiment by the researchers can overhaul the problems of the current experiments and it can be an effective alternative to the current experiment.