• Journal of Information Processing Systems
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• 제6권3호
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• pp.269-294
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• 2010

The interconnection of mobile devices in urban environments can open up a lot of vistas for collaboration and content-based services. This will require setting up of a network in an urban environment which not only provides the necessary services to the user but also ensures that the network is secure and energy efficient. In this paper, we propose a secure, energy efficient dynamic routing protocol for heterogeneous wireless sensor networks in urban environments. A decision is made by every node based on various parameters like longevity, distance, battery power which measure the node and link quality to decide the next hop in the route. This ensures that the total load is distributed evenly while conserving the energy of battery-constrained nodes. The protocol also maintains a trusted population for each node through Dynamic Trust Factor (DTF) which ensures secure communication in the environment by gradually isolating the malicious nodes. The results obtained show that the proposed protocol when compared with another energy efficient protocol (MMBCR) and a widely accepted protocol (DSR) gives far better results in terms of energy efficiency. Similarly, it also outdoes a secure protocol (QDV) when it comes to detecting malicious nodes in the network.

• 한국항공우주학회지
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• 제48권12호
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• pp.1021-1031
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• 2020

인공지능, 자율항법 등 4차 산업의 기술들이 발전하면서 도심항공교통(UAM)이 도심의 교통 체증에 대한 효과적인 대안으로 고려되고 있으며, 한국을 비롯한 세계의 많은 기업들이 비행체 개발과 운용 체계 연구를 수행하고 있다. 본 연구에서는 도심항공교통의 운용에 필요한 요소들을 식별, 분류한 뒤 운용 체계 개념을 수립하였으며, 각 요소별로 세부적 고려사항들을 분석하였다. 운용 체계 개념 분석 결과를 기반으로 서울시와 경인권을 연결하는 도심항공교통 운항경로를 구축하였으며, 비행체의 성능 분석을 통하여 구축된 운항경로가 운용이 가능함을 확인하였다. 본 경로 분석연구는 추후 국내 여러 도시의 도심항공교통 운항경로 수립에 적용이 가능할 것으로 예측된다.

• Spatial Information Research
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• 제9권2호
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• pp.171-184
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• 2001

현재 진행중인 정보화의 추세 속에서 도시계획 과정에서의 의사결정을 지원하기 위해 다양한 지식기반 공간분석 시스템이 개발되었으나 비구조화된 도시계획 문제의 특성으로 인해 그 적용이 어렵다. 이같은 문제의 해결을 위해 본 연구에서는 사례기반 추론에 의한 공간분석 시스템을 개발하고 이를 택지개발사업시 토지이용계획 과정에 도입하여 그 활용 가능성을 탐색해 보았다. 사례연구를 통한 실험의 결과, 개발된 공간분석 시스템의 적용 가능성이 확인되었다. 그러나 보다 충분한 양의, 건전한 내용의 사례 축적이 병행된다면 더욱 효과적인 추론을 수행할 수 있을 것이다.

• 한국컴퓨터정보학회논문지
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• 제17권5호
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• pp.93-101
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• 2012

도시계획이나 재난방재와 관련하여 지리정보시스템과 설계용 소프트웨어를 중심으로 한 다양한 소프트웨어들이 활용되고 있다. 그러나, 최근의 스마트폰 애플리케이션을 중심으로 한 모바일 환경의 변화와 3차원 지리정보시스템의 발전, 그리고 web 환경의 변화는 도시계획이나 재난방재 분야에 새로운 변화를 요구하고 있다. 특별히 Open API와 Mashup의 성장과 발전은 도시계획이나 재난방재 분야에 시민참여형 스마트폰 애플리케이션의 가능성을 넓혀주고 있다. 본 연구에서 제안하는 시민 참여형 스마트폰 애플리케이션 개발은 기술적, 경제적 및 행정적 파급효과를 가져올 뿐 아니라, 최근 활발히 건설되고 있는 U-City, U-health, 그리고 재난방재에 효과적인 역할을 할 것을 기대할 수 있다.

• 정보통신설비학회논문지
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• 제9권3호
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• pp.92-101
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• 2010

Energy efficiency and safe mobility are the two key constituents of the future automobile. The technologies that enable these features are now heavily dependent upon information and communication technology rather than traditional auto-mechanical technology. This paper presents an exploratory project 'Smart&Green Vehicle Project' at Western Michigan University which is to improve the geographical location accuracy of vehicles and to study various applications of making such location data available. Global Positioning System (GPS), Inertial Navigation System (INS), Vehicular Ad-hoc Network (VANET) technology, and data fusion among these technologies are investigated. Testing and evaluation is done on systems which will gather vehicular positioning data during GPS signal loss. Vehicles in urban settings do not acquire accurate positioning data from GPS alone; therefore there is a need for exploration into technology that can assist GPS in urban settings. The goal of this project is to improve the accuracy of positioning data during a loss of GPS signal. Controlled experiments are performed to gather data which aided in assessing the feasibility of these technologies for use in vehicular platforms.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.7-13
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• 2001

Geospatial Information Systems (GIS) have been employed to systematically manage and design land use in urban areas. This has increased the need for more accurate vector and raster data. In Korea, l/l,000-scale digital maps are used as vector data for the facility management in urban areas. This has increased the need for large scale orthoimages. Orthoimages generated from aerial imagery can provide accurate information, making possible the more effective city management. However, there is a large problem in using the orthoimages, i.e., currently available conventional orthoimages have not been generated based on Digital Elevation Model (DEM) that takes into account the building heights. So this causes the displacements of building image in large scale orthoimages. The present study is an attempt to generate the large scale orthoimages based on building DEM. The semiautomatic building extraction method can detect building outlines by mouse clicking on either building roofs or corners. Building DEM, based on the outline and calculated building height, was used to produce the large scale orthoimages with the corrected building occlusion.

• Tribology and Lubricants
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• 제29권1호
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• pp.51-55
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• 2013

In this work, a new fluorescence emission measurement technology was introduced and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate it for the oil oxidation measurement of electrical insulating oil. The oxidation characteristics of insulating oil were found to be fairly represented by the titration method and IR spectroscopy, and the results are comparable to a change in the fluorescence emission ratio that is defined as the shift in fluorescence intensity in the measured wavelength range. The result also shows that by the measurement of fluorescence emission ratio, it is possible to detect the oxidation of oil relatively earlier than by other methods. This study suggests that the developed technology can provide sufficient information for evaluating the insulating oil quality, and that the developed FER sensor can be used as an effective condition monitoring device of electrical insulating oil oxidation.

• 한국전자통신학회논문지
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• 제9권9호
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• pp.1057-1062
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• 2014

차량통신시스템은 차량/도로기술과 정보통신기술을 접목하여 다양한 안전메시지를 전송하거나 지능형 교통시스템에 적용이 가능하다. 본 논문에서는 IEEE 802.11p를 기반으로 한 차량통신시스템을 소개하고 이 시스템의 전파특성을 도심환경에서 측정한 결과를 보인다. 전파특성은 패킷오류율과 수신스펙트럼을 이용하여 측정한다. 이 결과를 바탕으로 하여 실제 서비스 적용에 있어서 필요한 구현 이슈에 대해 논의한다.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.54-60
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• 2012

In this paper, a new permanent-magnet (PM) linear motor is proposed, in which both the magnets and armature windings are placed in the short mover, while the long stator consists of iron core only. Hence, this new PM linear motor can be called a primary permanent-magnet linear motor. It exhibits the advantages of robustness, low cost, high efficiency, high power factor, and high thrust force density. It is especially suitable for long stator applications such as urban rail transit. In this paper, the topology and operation principle of this motor are discussed in detail. The steady-state characteristics including field distributions, flux-linkage, back-EMF, phase inductance and thrust force are investigated. In addition, the technique of skewing stator teeth is adopted to improve the electromagnetic performance. Results from finite element method (FEM) verified the theoretical analysis results.

• Journal of Information Technology Applications and Management
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• 제26권1호
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• pp.95-102
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• 2019

Public transportation systems play key roles in supporting dynamic activities and interaction between urban places. Especially, high efficient public transportation systems are required in order to support large traffic demands in urban areas. In this paper, we define a new metric, structural activation level (SAL), to replace the conventional transportation share ratio (TSR) measuring efficiency of public transportation systems. First of all, we access the Korea Transport Database (KTDB) and download origin-destination data by transport types to construct traffic networks with respect to transport types for each city. Then, we calculate the QAP (Quadratic Assignment Procedure) correlation between each traffic network and the total traffic network for each city to investigate SAL by comparing cities one another. The results of our investigation reveal inconsistency between TSR and SAL. In Daegu, TSR of public transportation systems is relatively low while SAL is high. In Deajeon, however, SAL is low while TSR is high. Therefore, we suggest to take into consideration SAL as well as TSR in order to investigate the degree of activation of public transportation.