• 제어로봇시스템학회논문지
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• 제20권1호
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• pp.48-57
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• 2014

It is suggested that the curvature trajectory be used to estimate the real-time moving sound sources and efficiently the robot estimating the sound sources. Since the target points of the real-time moving sound sources change, the mobile robot continuously estimates the changed target points. In such a case, the robot experiences a slip phenomenon due to the abnormal velocity and the changes of the navigating state. By selecting an appropriate curvature and navigating the robot gradually by using it, it is possible to enable the robot to reach the target points without having much trouble. In order to recognize the sound sources in real time, three microphones need to be organized in a straight form. Also, by applying the cross-correlation algorithm to the TDOA base, the signals can be analyzed. By using the analyzed data, the locations of the sound sources can be recognized. Based on such findings, the sound sources can be estimated. Even if the mobile robot is navigated by selecting the gradual curvature based on the changed target points, there could be errors caused by the inertia and the centrifugal force related to the velocity. As a result, it is possible to control the velocity of both wheels of the robot through the velocity PID controller in order to compensate for the slip phenomenon and minimize the estimated errors. In order to examine whether the suggested curvature trajectory is appropriate for estimating the sound sources, two mobile robots are arranged to carry out an actual experiment. The first robot is moved by discharging the sound sources, while the second robot recognizes and estimates the locations of the discharged sound sources in real time.

• Journal of information and communication convergence engineering
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• 제18권1호
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• pp.22-27
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• 2020

Content centric networking (CCN) is regarded as promising internet architecture because it can provide network efficiency in terms of bandwidth consumption by separating contents from a specific network location and decrease network congestion events. However, the application of a CCN does not widely consider the side effects of mobile devices, particularly mobile content sources. For content source mobility, a full routing update is required. Therefore, in this study, a route optimization scheme is proposed for mobile content sources in a CCN environment to provide low communication overhead, short download time, and low resource consumption. The proposed scheme establishes a direct path between content requesters and a mobile content source for the exchange of interest and data packets using interest-piggybacked data packets. Based on the inherent CCN naming characteristics, the content source does not know the name prefix of the content consumer, and thus the proposed optimized CCN scheme utilizes the content router in the home domain of the content source.

• 한국환경과학회지
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• 제11권7호
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• pp.697-703
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• 2002

In the present study, space allocation methods of pollutant emission from area and mobile sources are assessed by the actual application to air quality modeling of Pohang area. It is found that the TM-based modeling which allocates emission onto the 1km x 1km sized TM-grid system predicts almost the same mean ground-level concentration as that by the GIS-based modeling which uses geographical information of area and mobile sources directly, while maximum ground-level concentration by the TM-based modeling is predicted considerably lower than that by the GIS-based modeling. Moreover, the problem is found that the TM-based modeling causes deviation of mobile roads. In conclusion, it is anticipated to applying GIS-based modeling for a more accurate assessment of air quality in local scale.

• 정보과학회 논문지
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• 제41권11호
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• pp.967-973
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• 2014

연속개체는 크기가 크며, 확산하는 특징이 있다. 따라서 연속개체 탐지에서는 소스가 매우 많이 발생하며, 계속해서 새로운 소스가 발생하는 점을 고려해야 한다. 기존 연속개체 탐지 연구들은 탐지 정보를 고정된 싱크로 전달하는 상황만을 고려하고, 많은 소스로부터 발생하는 통신비용을 줄이기 위해 노력했다. 본 논문에서는 연속개체 탐지에서 효율적으로 이동싱크를 지원하는 방안을 제안한다. 이동싱크가 데이터를 받기 위해서는 소스에게 자신의 현재 위치를 알려야 한다. 기존 이동싱크 지원 방안들은 개별개체를 대상으로 했다. 이를 연속개체 탐지에 그대로 적용하면 연속개체의 수많은 소스들에게 개별적으로 현재 위치를 알려야 하며, 이는 심각한 에너지 낭비를 초래한다. 제안방안은 연속개체의 소스들의 지역성을 이용하여 이동싱크의 현재위치를 연속개체의 소스들에게 효율적으로 전달한다. 실험 결과는 제안방안이 기존 방안에 비해 이동싱크의 위치갱신을 수행할 때 더 적은 에너지를 소모함을 보인다.

• Journal of Information Processing Systems
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• 제3권2호
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• pp.64-72
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• 2007

Mobile technology appears promising as a method to promote group performance in circumstances dependent on time, but not member proximity. However, the success of mobile technology in group decision-making situations has not yet been proven. This paper aims to see how mobile technology affects the performance of group decision-making tasks that should be resolved urgently and/or sources of idea are disconnected with on-line network. Laboratory experiment was used to investigate the effects of mobile factors on group decision-making. The results from the experiment supported the proposition that pressures of time and location play a significant role in the assessment of group decision performance measures. We found that the adoption of mobile technology to group decision-making procedures might be competitive when group decision-making tasks are urgent and sources of idea are disconnected with on-line network, even though mobile technology is not a panacea on which to depend when designing group decision-making.

• 대한인간공학회지
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• 제27권3호
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• pp.61-69
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• 2008

The purpose of this study was to examine the effects of sensibility and compatibility from function sounds of mobile phones. For this purpose, the present study extracted sensibility adjectives and carried out sensibility evaluation to identify the sensibility factors in the function sounds of mobile phones. And 65 sound sources out of six categories were investigated for 27 subjects. The result showed that two dominant sensibility factors were the duration and the melody pattern of the sound sources. The compatibilities of opening and closing sounds were evaluated lowly with short duration and quick tempo. Especially, the most of the subjects preferred more attractive and longer opening sounds than other function sounds. Another finding was that the short sounds with melodies were preferred for cancellations and alerts, unliked the commonly used sound sources in industry and other traditional electronic products.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제5권12호
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• pp.455-462
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• 2016

무선 센서 네트워크는 센서 필드 상의 이벤트에 관한 데이터를 소스로부터 싱크로 수집하기 위해 연구되어왔다. 멀티패스 라우팅은 노드나 링크 단절에 의해 소스에서 싱크로의 패스가 종종 손실되는 문제에 대해 신뢰성 있는 데이터전송을 위한 매력적인 방안 중 하나이다. 사람이나 동물 혹은 차량 등과 같은 모바일 이벤트 상황에서, 소스는 이 모바일 이벤트의 이동에 따라 연속적으로 소스가 발생할 수 있다. 따라서 멀티패스 라우팅에서 모바일 이벤트의 상황은 새로운 도전 과제를 제시한다. 그러나 기존의 멀티패스 라우팅 연구는 주로 소스들에서 정적인 싱크로 효율적인 멀티패스 구성과 패스 단절에 대한 빠른 멀티패스 재구성에 초점을 두었다. 따라서 이전 멀티패스 라우팅 프로토콜은 모바일 이벤트에 의해 발생하게 되는 연속적인 각각의 소스들이 소스에서 싱크로 각각의 멀티패스를 필요로 한다. 이는 이전 방안이 소스의 수에 비례하여 멀티패스 구성비용이 증가게 한다. 따라서 우리는 모바일 이벤트에 의해 연속적으로 발생하게 되는 소스를 지원하는 효율적인 멀티패스 라우팅 프로토콜을 제안한다. 제안방안에서 이전 소스에서 만들어 놓은 기존의 멀티패스를 이용함으로써, 새로운 소스가 효율적으로 재구성을 할 수 있다. 이를 위해, 제안방안은 지역적 멀티패스 재구성, 광역적 부분 멀티패스 재구성, 광역적 전체 멀티 패스 재구성의 세 방안 중 하나를 선택한다. 이 선택을 위해 우리는 멀티패스 재구성 비용과 데이터 포워딩 비용의 합을 계산하는 분석적인 에너지 소비 비용 모델을 제시한다. 시뮬레이션 결과 모바일 이벤트의 상황에서 멀티패스 라우팅을 할 때 제안방안이 기존의 방안보다 우수한 성능을 보였다.

• Asian Journal of Atmospheric Environment
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• 제9권2호
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• pp.146-157
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• 2015

Emissions of ozone precursors ($NO_x$ and VOCs) and photochemical ozone creation potentials (POCPs) of VOC emission sources were investigated in the largest port city (i.e., Busan), Korea during the year 2011. This analysis was performed using the Clean Air Policy Support System (CAPSS) national emission inventory provided by the National Institute of Environmental Research (NIER), Korea. For $NO_x$, the emissions from off-road mobile sources in Busan were the most dominant (e.g., $31,202ton\;yr^{-1}$), accounting for about 60% of the total $NO_x$ emissions. The emission from shipping of off-road mobile sources (e.g., $24,922ton\;yr^{-1}$) was a major contributor to their total emissions, amounting to 47% of the total $NO_x$ emissions due to the port-related activities in Busan. For VOCs, the emission source category of solvent usage was predominant (e.g., $36,062ton\;yr^{-1}$), accounting for approximately 82% of the total VOC emissions. Out of solvent usages, the emission from painting was the most dominant ($22,733ton\;yr^{-1}$), comprising 52% of the total emissions from solvent usages. The most dominant VOC species emitted from their sources in Busan was toluene, followed by xylene, butane, ethylbenzene, n-butanol, isopropyl alcohol, and propane. The major emission sources of toluene and xylene were found to be painting of coil coating and ship building, respectively. The value of POCP for the off-road mobile source (61) was the highest in ten major activity sectors of VOC emissions. Since the POCP value of ship transport of off-road mobile source (72) was also high enough to affect ozone concentration, the ship emission can play a significant role in ozone production of the port city like Busan.

• Asian Journal of Atmospheric Environment
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• 제2권1호
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• pp.34-46
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• 2008

Emissions inputs for use in air quality modeling of Korea were generated with the emissions inventory data from the National Institute of Environmental Research (NIER), maintained under the Clean Air Policy Support System (CAPSS) database. Source Classification Codes (SCC) in the Korea emissions inventory were adapted to use with the U.S. EPA's Sparse Matrix Operator Kernel Emissions (SMOKE) by finding the best-matching SMOKE default SCCs for the chemical speciation and temporal allocation. A set of 19 surrogate spatial allocation factors for South Korea were developed utilizing the Multi-scale Integrated Modeling System (MIMS) Spatial Allocator and Korean GIS databases. The mobile and area source emissions data, after temporal allocation, show typical sinusoidal diurnal variations with high peaks during daytime, while point source emissions show weak diurnal variations. The model-ready emissions are speciated for the carbon bond version 4 (CB-4) chemical mechanism. Volatile organic carbon (VOC) emissions from painting related industries in area source category significantly contribute to TOL (Toluene) and XYL (Xylene) emissions. ETH (Ethylene) emissions are largely contributed from point industrial incineration facilities and various mobile sources. On the other hand, a large portion of OLE (Olefin) emissions are speciated from mobile sources in addition to those contributed by the polypropylene industry in point source. It was found that FORM (Formaldehyde) is mostly emitted from petroleum industry and heavy duty diesel vehicles. Chemical speciation of PM2.5 emissions shows that PEC (primary fine elemental carbon) and POA (primary fine organic aerosol) are the most abundant species from diesel and gasoline vehicles. To reduce uncertainties in processing the Korea emission inventory due to the mapping of Korean SCCs to those of U.S., it would be practical to develop and use domestic source profiles for the top 10 SCCs for area and point sources and top 5 SCCs for on-road mobile sources when VOC emissions from the sources are more than 90% of the total.

• 제어로봇시스템학회논문지
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• 제17권2호
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• pp.108-115
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• 2011

This paper describes a new sensor system for mobile robot motion estimation using stereo infrared light sources and a camera. Visibility is being applied to robotic obstacle avoidance path planning and localization. Using simple visibility computation, the environment is partitioned into many visibility sectors. Based on the recognized edges, the sector a robot belongs to is identified and this greatly reduces the search area for localization. Geometric modeling of the vision system enables the estimation of the characteristic pixel position with respect to the robot movement. Finite difference analysis is used for incremental movement and the error sources are investigated. With two characteristic points in the image such as vertices, the robot position and orientation are successfully estimated.