• 반도체디스플레이기술학회지
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• 제20권2호
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• pp.67-72
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• 2021

MANET(Mobile Ad Hoc Network) is the structure in which a source node communicates with a destination node by establishing a route with neighbor nodes without using the existing wired or wireless network. Therefore, the routing protocol for MANET must correspond well to changes in the channel state of moving nodes, and should have simple operation, high reliability, and no routing loop. In this paper, the simulation was perform by using a traffic model with on/off two states provided by the NS-3 network simulator. Also, the duration of the ON state and the duration of the OFF state used the traffic where inter arrival time of data is irregular by generating random values with constant, exponential distribution, and Pareto distribution. The performance of the DSDV, OLSR, and AODV protocols was compare and analyzed using the generated traffic model.

• 대한전자공학회논문지
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• 제23권1호
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• pp.91-100
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• 1986

The nonlinear rate equations are solved analytically by using the singular perturbation method to study effects of the spontaneous emission factor and the photon lifetime on the primary resonance and the first subharmonic generation(i.e., the onset of the periocd-doubling route to chaos). By large signal modulation of Hitachi CSP laser HLP 1400, the resonance frequency shift than 100 ps with 1 GHz repetition rate are generated. The experimental observations are in reasonable agreement with the theoretical results obtained using measured parameters of the rate equations.

• 한국교육논총
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• 제41권1호
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• pp.59-79
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• 2020

인간의 학습은 정해진 노선이 없다. 즉 어떤 길로 가도 되고 이르는 길 또한 천태만상이라는 것이다. 이는 현대사회에서 논의되어지는 복잡계의 구조에서도 살펴볼 수 있고, 동양의 오랜 고전인 『주역』을 통해서도 살펴볼 수 있다. 인간의 학습 자체는 무형식학습에서 시작해서 오늘날의 형식학습까지 전개되어 왔다. 인류 문명의 발달 단계를 살펴나가다 보면 이러한 발달 단계를 쉽게 발견할 수 있다. 인간에게 있어 인간 자신이라는 문제는 언제나 많은 논의가 되어왔고, 이 논의는 아직도 진행 중이다. 인간은 언어와 도구를 통해, 그리고 기술과 문화를 통해, 그리고 철학과 예술·종교를 통해 그들의 복잡하고 다양한 정신세계를 다루고 담아냈다. 또 이러한 다양한 활동을 통해 학습이 이루어져 왔다. 이는 한 세대의 유전을 통한 육체 과정에 한하지 않고, 학습이라는 정신과정으로 삶의 확장을 이루어낸다. 인간의 마음과 학습은 언제나 현재진행형일 수밖에 없는 이유도 여기에 있다. 본 연구는 복잡다양하고 다원화된 현대사회에서 어떤 학습을, 그리고 어떻게 함께 공존해나가야 할지를 복잡계의 원리와 『주역』의 사유방식을 통해 모색해보고자 한다.

• International journal of advanced smart convergence
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• 제6권1호
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• pp.82-88
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• 2017

Emergency lights and exit signs are an indispensable part of safety precautions for effective evacuation in case of emergency in public buildings. These emergency sign indicates safe escape routes and emergency doors, using an internationally recognizable sign. However visibility of those signs drops drastically in case of emergency situations like fire smoke, etc. and loss of visibility causes serious problems for safety evacuation. This paper propose a novel emergency light and exit sign built-in with Bluetooth Low Energy (BLE) Beacon to assist the emergency self-guiding evacuation using devices for crisis and emergency management to avoid panic condition inside the buildings. In this approach, the emergency light and exit sign with the BLE beacons deployed in the indoor environments and the smart devices detect their indoor positions, direction to move, and next exit sign position from beacon messages and interact with map server in the Internet / Intranet over the available LTE and/or Wi-Fi network connectivity. The map server generate an optimal emergency exit path according to the nearest emergency exit based on a novel graph generation method for less route computation for each smart device. All emergency exit path data interfaces among three system components, the emergency exit signs, map server, and smart devices, have been defined for modular implementation of our emergency evacuation system. The proposed exit sign experimental system has been deployed and evaluated in real-time building environment thoroughly and gives a good evidence that the modular design of the proposed exit sign system and a novel approach to compute emergency exit path route based on the BLE beacon message, map server, and smart devices is competitive and viable.

• 한국농공학회논문집
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• 제50권5호
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• pp.3-15
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• 2008

This study aims to simulate the 3 dimensional (3D) model of Keum-man connection canal using geographic information system (GIS) as well as considering design in viewpoint of engineering. The canal connects from Keumkang to Mangyungkang in order to supply fresh water into Saemankeum lake. This study used 3 dimensional spatial planning model (3DSPLAM) process to generate the 3D model, which has not only several planning layers in actual process, but also their corresponding layers in modeling process to simulate 3D space of rural villages. The discharge of the canal is $20m^3/s$ on slope of 1/28,400 in the canal length of 14.2km, which consists of pipe line and open channel. This study surveyed the route of the canal and its surrounding environment for facilities to make images in the 3D graphic model. Besides, the present study developed data set in GIS for geogrphical surface modeling as well as parameters in hydraulic analysis for water surface profile on the canal using HEC-RAS model. From the data set constructed, this study performed analysis of water surface profile with HEC-RAS, generation of digital elevation model (DEM) and 3D objects, design of the canal section and route on DEM in AutoCAD, and 3D canal model and its surrounding 3D space in 3DMAX with virtual reality. The study result showed that the process making 3D canal model tried in this study is very useful to generate computer graphic model with the designed canal on the surface of DEM. The generated 3D canal can be used to assist decision support for the canal policy.

• 한국컴퓨터정보학회논문지
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• 제27권10호
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• pp.137-146
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• 2022

최근 수요가 많아진 여행 일정 추천 서비스와 관련하여, 이전 연구에서는 소셜 빅데이터 분석을 통해 관광지, 맛집, 숙소 등을 포함한 플레이스들의 대중적인 인기 정도를 정량화하고, 분석결과를 기반으로 여행 스케줄을 생성하기 위한 방법을 소개하였다. 그러나 생성된 스케줄은 관광지를 최단 거리로 연결한 이동 경로 위주로 구성되었으며, 여행 일자별로 맛집이나 숙소 정보를 포함한 구체적인 일정 정보는 제공하지 않았다. 본 논문에서는 소셜 빅데이터를 기반으로 생성된 여행 스케줄에 시나리오 템플릿을 이용하여 상세 이동 경로를 구성하기 위한 알고리즘을 제시하고, 이를 구현한 프로토타입 시스템에 대해 소개한다. 제안 시스템은 플레이스 정보 수집, 플레이스별 인기점수 산정, 최단경로 여행 일정 생성, 일자별 상세 스케줄 생성, UI 시각화 등의 모듈로 구성되며, 경상남도 내 63,000여 개의 플레이스를 대상으로 수집된 리뷰를 바탕으로 진행된 실험을 통해 제안 시스템의 효용성을 입증하였다.

• 한국산업융합학회 논문집
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• 제26권5호
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• pp.775-784
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• 2023

Drone images are being used more and more actively in the fields of surveying and spatial information, and are rapidly replacing existing aerial and satellite images. The technology of quickly acquiring real-time data at low cost and processing it is now being applied to actual industries beyond research. However, there are also problems encountered as this progresses. When high-resolution spatial information is acquired using a general 2D flight plan for a terrain with sever undulations, problems arise due to the difference in resolution of the data. In particular, when a low-altitude high-resolution image is taken using a drone in a mountainous or steep terrain, there may be a problem in image matching due to a resolution difference caused by terrain undulations. This problem occurs because a drone acquires data while flying on a 2D plane at a fixed altitude, just like conventional aerial photography. In order to acquire high-quality 3D data using a drone, the scale difference for the shooting distance should be considered. In addition, in order to obtain facade images of large structures, it is necessary to take images in 3D space. In this study, in order to improve the disadvantages of the 2D flight method, a 3D flight plan was established for the study area, and it was confirmed that high-quality 3D spatial information could be obtained in this way.

• 해양환경안전학회지
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• 제21권5호
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• pp.583-590
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• 2015

우리나라 서남해역에서 추진될 해상풍력 발전 단지에서 생산된 전기와 기존의 전력망과의 계통연계를 위해서는 해저케이블 설치가 필수적인 요소이다. 특히 해저케이블 설치에 대한 경제성, 시공성 및 안정성 확보를 위해서는 해저케이블 경과지와 해저케이블 보호공법 설계가 이루어져야한다. 본 논문에서는 1979년부터 2002년까지 한국해양과학기술원에서 구축한 장기 파랑산출자료와 제3세대 파랑 모델인 SWAN(Simulating WAves Nearshore)을 이용하여 해상풍력단지가 조성될 해역에 대해 만조와 간조시 파랑시뮬레이션을 수행하여 해저케이블 경과지와 보호공법 설계를 위한 기초자료를 제공하고자 하였다. 연구결과, 서남해 해상풍력단지가 조성될 해역의 연평균 Hs는 1.03 m, Tz는 4.47s이고, 주파향은 북서(NW)와 남남서(SSW) 방향이다. NW에서 입사되는 조건(Hs: 7.0 m, Tp: 11.76s)에서 만조시 천해설계파랑 Hs의 분포는 약 4.0~5.0 m, 간조시에 약 2.0~3.0 m로 계산되었다. SSW에서 입사되는 조건(Hs: 5.84 m, Tp: 11.15s)에서 만조시 천해설계파랑 Hs의 분포는 약 3.5~4.5 m이고, 간조시에는 약 1.5~2.5 m로 계산되었다. 해저케이블 경과지 중 경도 UTM 249749~251349 구간 약 1.6 km에서는 NW로 입사되는 파랑의 영향이 크며, UTM 251549~267749 구간 약 16.2 km에서는 SSW로 입사되는 파랑의 영향이 지배적이다. 파랑집중 현상이 두드러지게 나타나는 해역은 위도와 하왕등도 사이 해역으로, 이 해역에서는 주변해역 보다 상대적으로 높은 파고를 나타내고 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1097-1106
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• 2007

Rail provides running tract for train and broadly and widely conveys the weight of the train exerted from the train wheels that the rail directly supports onto the cross tie and roadbed, and supports the cross-sectional pressure exerted by centrifugal force at curvatures. That is, stationary rail provides surface on which dynamic train runs and guarantees cross-sectional resistance to enable the vertical snake motion of the train wheels as well as to maintain lateral force at curvatures. Rail provides running surface on which train wheels can run smoothly, and secures vertical and lateral force. However, it undergoes continuous destructive reactions (wearing and damages) and abrasion of the cladding by the train wheels. It is obvious that wearing will result when two metal parts act against each other. However, occurrence of abnormal wearing such as rapid wearing of the rail side due to complex generation of various mechanisms at the contact surface between the rail and train wheel flange. It is not easy to simply examine the causes of occurrence of abnormal wearing of rail and train wheel flange. Although countless number of academicians and specialists are conducting researches on abnormal wearing of rail and vertical wearing of train wheels, I believe it is too early to argue on pros and cons due to insufficiency of officially verified information on the issue. This review will be focusing on the examples of repairs that reduced the generation of abnormal wearing of rail by reviewing and improving characteristics of wearing and slack, speed of the train and cant as well as status of lubricator by choosing the compound curves present in the section between the $Anguk{\sim}Jongno3-ga$ Stations of the Route No. 3 among the compound curve tracks of the Seoul Metro Routes No. 3 & 4 at which abnormal wearing is generated continuously.

• ETRI Journal
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• 제40권1호
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• pp.39-50
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• 2018

More people prefer using rail traffic for travel or for commuting owing to its convenience and flexibility. The railway scenario has become an important communication scenario in the fifth generation era. The communication system should be designed to support high-data-rate demands with seamless connectivity at a high mobility. In this paper, the channel characteristics are studied and modeled for the railway tunnel scenario with straight and curved route shapes. On the basis of measurements using the "Mobile Hotspot Network" system, a three-dimensional ray tracer (RT) is calibrated and validated for the target scenarios. More channel characteristics are explored via RT simulations at 25.25 GHz with a 500-MHz bandwidth. The key channel parameters are extracted, provided, and incorporated into a 3rd-Generation-Partnership-Project-like stochastic channel generator. The necessary channel information can be practically realized, which can support the link-level and system-level design of the communication system in similar scenarios.