• 방송공학회논문지
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• 제27권7호
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• pp.974-984
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• 2022

In this paper, we introduce the minimum and maximum distance setting methods used in geometric distance attenuation processing, which is one of spatial sound reproduction methods. In general, sound attenuation by distance is inversely proportional to distance, that is 1/r law, but when the relative distance between the user and the audio object is very short or long, exceptional processing might be performed by setting the minimum distance or the maximum distance. While MPEG-I Immersive Audio's RM0 uses fixed values for the minimum and maximum distances, this study proposes effective methods for setting the distances considering the signal gain of an audio object. Proposed methods were verified through simulation of the proposed methods and experiments using RM0 renderer.

• Bulletin of the Korean Chemical Society
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• 제23권1호
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• pp.71-74
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• 2002

The apparent barrier height for charge transfer through an interfacial water layer between a Pt/Ir tip and a gold surface has been measured using STM technique. The average thickness of the interfacial water layer inside an STM junction was controlled by the amount of moisture. A thin water layer on the surface was formed when relative humidity was in the range of 10 to 80%. In such a case, electron tunneling through the thin water layer became the majority of charge transfers. The value of the barrier height for the electron tunneling was determined to be 0.95 eV from the current vs. distance curve, which was independent of the tip-sample distance. On the other hand, the apparent barrier height for charge transfer showed a dependence on tip-sample distance in the bias range of 0.1-0.5 V at a relative humidity of approximately 96%. The non-exponentiality for current decay under these conditions has been explained in terms of electron tunneling and electrochemical processes. In addition, the plateau current was observed at a large tip-sample distance, which was caused by electrochemical processes and was dependent on the applied voltage.

• 환경영향평가
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• 제19권3호
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• pp.223-230
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• 2010

Trajectory dispersion models are used for the dispersion calculations in air quality assessments, Yellow-sand modeling, environmental planning and the emergency response. Meso-scale forcing and coastal circulations are calculated by trajectory model in the East Asia region. In this study the meteorological fields (GDAS and MM5) coupled to the trajectory model (HY-SPLIT) are applied to simulate the transport and the dispersion. Seoul is selected as a starting point of the HY-SPLIT. The sensitivity studies are performed by conducting an ensemble of simulations using the GDAS and the MM5 model for the same dispersion cases. The results in this study show a significant difference depending on the resolution of meteorological models. Additionally, in most cases of the compared tionally,results from MM5 and GDAS, the absolute and relative distance, shows significant difference and the difference increased with the increasing distance of HY-SPLIT. Therefore, for the case of small domai for twi d field distefbution over complex terrai, should be used only high model temporal or spatial resolution to improve the HY-SPLIT model results.

• Journal of Information Processing Systems
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• 제16권1호
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• pp.155-170
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• 2020

Passive ranging is a critical part of machine vision measurement. Most of passive ranging methods based on machine vision use binocular technology which need strict hardware conditions and lack of universality. To measure the distance of an object placed on horizontal plane, we present a passive ranging method based on monocular vision system by smartphone. Experimental results show that given the same abscissas, the ordinatesis of the image points linearly related to their actual imaging angles. According to this principle, we first establish a depth extraction model by assuming a linear function and substituting the actual imaging angles and ordinates of the special conjugate points into the linear function. The vertical distance of the target object to the optical axis is then calculated according to imaging principle of camera, and the passive ranging can be derived by depth and vertical distance to the optical axis of target object. Experimental results show that ranging by this method has a higher accuracy compare with others based on binocular vision system. The mean relative error of the depth measurement is 0.937% when the distance is within 3 m. When it is 3-10 m, the mean relative error is 1.71%. Compared with other methods based on monocular vision system, the method does not need to calibrate before ranging and avoids the error caused by data fitting.

• 한국지능시스템학회논문지
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• 제23권6호
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• pp.527-532
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• 2013

깊이 추정은 로봇 비전, 3차원 영상, 모션 제어를 위해 사용되는 매우 중요한 인자이다. 깊이 추정은 렌즈와 물체 사이의 거리를 변화시켜가면서 취득된 일련의 영상에서 계산된 초점 정보에 기반을 둔다. 본 논문에서는 다양한 초점정보를 이용한 패턴간의 상대적 깊이 추정 알고리즘을 제안한다. 제안된 방법은 거리별로 취득된 영상의 초점값 정보를 이용하여 구현하였으며, 깊이는 두 패턴의 상대적 거리를 고려함으로써 추정하였다. 다양한 영상정보를 이용하여 깊이 추정을 수행한 결과 효과적인 추정이 가능함을 알 수 있었다.

• Journal of Astronomy and Space Sciences
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• 제35권4호
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• pp.263-277
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• 2018

This paper presents a vision-based relative pose estimation algorithm and its validation through both numerical and hardware experiments. The algorithm and the hardware system were simultaneously designed considering actual experimental conditions. Two estimation techniques were utilized to estimate relative pose; one was a nonlinear least square method for initial estimation, and the other was an extended Kalman Filter for subsequent on-line estimation. A measurement model of the vision sensor and equations of motion including nonlinear perturbations were utilized in the estimation process. Numerical simulations were performed and analyzed for both the autonomous docking and formation flying scenarios. A configuration of LED-based beacons was designed to avoid measurement singularity, and its structural information was implemented in the estimation algorithm. The proposed algorithm was verified again in the experimental environment by using the Autonomous Spacecraft Test Environment for Rendezvous In proXimity (ASTERIX) facility. Additionally, a laser distance meter was added to the estimation algorithm to improve the relative position estimation accuracy. Throughout this study, the performance required for autonomous docking could be presented by confirming the change in estimation accuracy with respect to the level of measurement error. In addition, hardware experiments confirmed the effectiveness of the suggested algorithm and its applicability to actual tasks in the real world.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.123-129
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• 2002

This paper proposes a vehicle trajectory prediction method far application to vehicle-to-vehicle distance control. This method is based on 2-dimensional kinematics and a Kalman filter has been used to estimate acceleration of the object vehicle. The simulation results using the proposed control method show that the relative distance characteristics can be improved via the trajectory prediction method compared to the customary intelligent cruise control algorithm.

• 산업경영시스템학회지
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• 제20권41호
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• pp.213-220
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• 1997

Process capability Indices compare the actual performance of manufacturing process to the desired performance. The relationship between the capability index Cpm and the expected squared error loss provides an intuitive interpretation of Cpm. By putting the loss in relative terms a user needs only to specify the target and the distance from the target at which the product would have zero worth, or alternatively, the loss at the specification limits. Confidence limits for the expected relative loss are discussed, and numerical illustration is given.

• 영어어문교육
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• 제5호
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• pp.63-78
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• 1999

In this paper, I explain why local obviation (Condition B of Chomskys binding theory) should be viewed as a relative phenomenon, and establish a correlation between Local Obviation (henceforth LO) effects and the Referential Hierarchy of Korean anaphors proposed in Lee (1997): ku (he) > caki (self) > casin (self) > cakicasin (selfself) = selo (each other). I show that LO characterized as a relative phenomenon may enable us to view Conditions B and C of the binding theory simply as an instantiation of varying degrees of (long distance) disjoint reference effects on the same continuum.

• 대한교통학회지
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• 제27권1호
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• pp.35-42
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• 2009

환승센터의 계획이나 개선시 제일 먼저 부딧히는 문제의 하나는 어느 수단을 얼마나 가깝게 위치시켜야 하는가 하는 것이다. 이때의 목표는 중심 수단을 이용하는 승객이 가능한 한 최단거리를 걸어서 다른 수단으로 연결될 수 있게 하는 것이다. 이 문제가 결정되고 난 후에 라야 연결 통로에 대한 서비스 수준을 향상시키는 문제를 제기할 수 있다. 물리적인 접근 거리가 너무 긴 경우 개별 통로의 서비스수준을 아무리 높여도 전체적인 환승만족도가 일정수준이상 향상되기 어렵기 때문이다. 본 연구에서는 한 수단의 도착지에서 다른 수단의 출발지까지의 전 과정 (환승패스)을 외부보도구간, 계단구간, 실내통로구간으로 나누어 이용자 설문조사를 통하여 상대적인 저항감을 구하여 합산된 환승저항을 계산하고, 이를 전반적인 환승만족도와 연결시켜 환승효용함수를 구하고 이를 토대로 환승패스의 개선 방향을 결정하는 방법을 논하였다.