• 한국정보통신학회논문지
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• 제18권8호
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• pp.1791-1797
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• 2014

수자원 관리를 위하여 활용되고 있는 FMCW 레이다 센서는 비트 주파수를 추정함으로서 표면 수위를 측정한다. 따라서 비트 주파수 추정치에서의 높은 신뢰성 및 정확도가 요구된다. 그러나 수위에 따른 비트 스펙트럼은 시스템의 주파수 선형성 및 측정 환경, 기상 상태에 따라 매우 다양한 형태를 나타낼 수 있다. 따라서 현재 사용되는 기존의 수위정보 추출 알고리즘의 정확도 및 신뢰성에 심각한 문제가 발생할 수 있다. 따라서 본 논문에서는 기존의 방법을 개선할 수 있는 고 해상도 비트 스펙트럼 추정에 의한 수위 정보 추출 방법들을 분석하였다. 이러한 방법들은 SNR 이 일정 기준 이상인 경우 더 정밀한 수위의 측정이 가능함을 보여준다. 그러나 SNR 이 매우 낮은 상황에서는 절대적인 오차수준이 크게 나타나지만 오히려 기존의 방법이 상대적으로 더 높은 신뢰도를 보인다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제2권1호
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• pp.34-38
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• 2010

Field investigations have been carried out in two 60-day stages on the surf beat low frequency waves in Anzali port, one of the main commercial ports in Iran, located in southwest coast of the Caspian Sea. The characteristics of significant water waves were measured at three metering stations in the sea, one at the entrance of the port and three in the basin. The measured data were inspected to investigate the surf beat negative effects on the tranquility of the port. Using field measurements and complementary numerical modeling, the response of the basin to the infra-gravity long waves was inspected for a range of wave frequencies. It was concluded that the water surface fluctuations in the port is strongly related to the incident wave period. The long waves with periods of about 45s were recognized as the worst cases for water surfaceperturbation in the port. For wave periods higher than the mentioned range, the order of fluctuation was generally low.

• 한국컴퓨터정보학회논문지
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• 제9권1호
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• pp.25-30
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• 2004

본 논문은 지휘자의 지휘 동작으로부터 일련의 영상들을 추출하여 지휘자가 지휘하는 박자를 인식하는 방법을 제안하고 있다 색상판별에 의해서 손의 위치를 감지하였으며 양자화를 통해서 그 위치를 기호화함으로써 지휘 동작을 일련의 기호로 표현하였다. 변형을 포함하는 기호열의 인식에 좋은 결과를 보이는 HMM(Hidden Markov Model)을 사용함으로써 표현된 기호열을 지휘박자로 인식하도록 하는 시스템을 구성하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.776-779
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• 2005

Liquefied Natural Gas takes up six hundredths of the volume of natural gas, which makes storage and transportation much easier. To send out natural gas via a pipeline network across the nation, high pressure LNG pumps supply highly compressed LNG to high-pressure vaporization facilities. The Number of high Pressure LNG pumps determined the send out amount in LNG receiving terminal. So it is main equipment at LNG production process and should be maintained on best conditions. In this paper, to find out the cause of high beat vibration at cryogenic pumps, vibration and motor current analysis have been performed. And high beat vibration of cryogenic pumps could be reduced due to the modification of motor rotor.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2015년도 춘계 종합학술대회 논문집
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• pp.13-14
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• 2015

In the past few decades, many catastrophic natural disasters have occurred not only in Japan and Korea, but also in other countries in the world, forcing people to live in unfamiliar houses for middle or long range evacuation periods. Residents staying in temporary houses exhibit insomnia, resulting in severe fatigue. In order to investigate sleeping state of residents, measuring vital signals has been performed at examination room of a hospital. To avoid the restriction of residents' movement, we propose to use smartphone and/or wearable devices with various high performance sensors like measuring heart beat rate. We clarify the availability and usefulness of those devices as support for analyzing daily sleeping state of residents.

• Journal of information and communication convergence engineering
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• 제16권3호
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• pp.189-196
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• 2018

Player's actions in a game occur in the process of gameplay experiences in a play space designed by the developer according to preset gameplay beats. Focusing on beats that induce a first-person shooter (FPS) game's main gameplay, this paper analyzes the differences in eye gaze information found in different players during the course of gameplay. For this research goal, the study divides the beat areas in which play actions appear in association with gameplay beats at a typical FPS game level, repeatedly conducts tests in accordance with a player's experience level (novice and expert group), and collects and analyzes eye gaze information data in three types of beat areas. The analysis result suggests concrete guidelines for game level design for different beat areas based on an FPS game player's experience level. This empirical experiment method and result can lessen repetitive modification work for game level design and consequently be utilized for optimizing the game level to the developer's intention.

• 산업기술연구
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• 제38권1호
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• pp.1-7
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• 2018

This paper introduces the design, casting, and sound evaluation results of the Great Bell of 2018 Pyeongchang Winter Olympics. The Olympic Bell was manufactured to announce the opening of the successful Winter Olympics in the world with a grand sound. The bell was designed to the dynamic shape to give a grand and harmonious sound in consideration of the global sports festival. In this study, the performance of the beat making the sound magnificent and the harmony of the bell sound were quantitatively evaluated using acoustical factors. Beat maps were investigated to understand the directivity of the beating sound. The purpose of the research is to present the production technique of a traditional Korean bell that has a dynamic shape and a grand and harmonious sound.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.334-336
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• 2007

This paper presents a beat gesture recognition method to synchronize the tempo of a robot playing a piano with the desired tempo of the user. To detect an unstructured beat gesture expressed by any part of a body, we apply an optical flow method, and obtain the trajectories of the center of gravity and normalized central moments of moving objects in images. The period of a beat gesture is estimated from the results of the fast Fourier transform. In addition, we also apply a motion control method by which robotic fingers are trained to follow a set of trajectories, Since the ability to track the trajectories influences the sound a piano generates, we adopt an iterative learning control method to reduce the tracking error.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1196-1198
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• 2000

In this paper, a new approach for digital feedback control of PWM inverter is proposed, in which an output DB(Dead-Beat) control is achieved combined with a simple disturbance observer. The deadbeat controller, which is constructed multiple loop control scheme for PWM inverter, is used for fast transient response. The disturbance observer can make the disturbances be cancelled by adding feedforward compensating loop in controller. The simulation result show the proposed control scheme can achieved good voltage regulation against large load variations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.922-925
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• 2005

This article describes a FM modulation algorithm to increase the measurement speed by increasing the beat frequency of the laser without acousto-optic modulator(AOM) in the heterodyne laser interferometer. The proposed algorithm can increase the beat frequency of the heterodyne laser which limit the measurement speed by adjusting a carrier frequency through electronic circuit, while AOM is used to shift the frequency of the heterodyne laser in conventional method. Electronic circuit is constructed to modulate the signals from a laser interferometer and a waveform generator. The brier analysis, the measurement scheme of the system, and the experimental results using a Zeeman-stabilized He-Ne laser are presented. They demonstrate that the proposed algorithm is proven to enhance the measurement speed limit by increasing the beat frequency of the heterodyne laser.