• Title/Summary/Keyword: radio map

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A Study on Updating of Digital Map using Beacon GPS (Beacon GPS를 이용한 수치지도 갱신에 관한 연구)

  • Yun, Bu-Yeol;Moon, Doo-Youl;Hong, Soon-Heon
    • Journal of the Korean Geophysical Society
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    • v.9 no.4
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    • pp.387-395
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    • 2006
  • Nowadays, various digital maps on a reduced scale were drawn in Korea including the topographic series of a nation. Though these digital maps are drawn and revised by using aerial photograph or satellite image, there are some problems that it is difficult to revise or renew the topography and natural feature immediately which changes frequently. As the countermeasures of these problems we use GPS accumbency method, which provides user with convenience and accumbency accuracy which is required to revise and renew digital maps. But acquiring correct position by using GPS only may cause not a few errors because of environmental effect of satellite signal errors that GPS obtains. Although accumulated errors which is the major problem of existing method was diminished owing to the position signal received from satellite which is about 20,183km above, the area that can not receives the signal is occur such as woods and high-rise buildings space. And because of the GDOP (Geometry Dilution of Precision) of GPS satellite and the periodically changing orbit of the satellite, the position calculating problems occur. For settlement of these problems and accurate position determination, DGPS (Differential GPS) is indispensably needed. So, in this study, by adapting Radio Beacon Receiver for marine position determination which is the most convenience method of DGPS methods, we elevated accuracy of modification and renewal of digital map and, having wide application in various measurements, proposed the rapid measurement method about widespread area. In this study, wewant to propose the work scheme of rapid modification and renewal of digital map by using Beacon GPS which is comparatively cheap of all the DGPS methods and which makes it possible to measure independently.

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Funology Body : Classified Application System Based on Funology and Philosophy of the Human Body (Funology Body : Funology와 '몸의 철학' 이론을 바탕으로 한 어플리케이션 분류 검색 체계 연구)

  • Kihl, Tae-Suk;Jang, Ju-No;Ju, Hyun-Sun;Kwon, Ji-Eun
    • Science of Emotion and Sensibility
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    • v.13 no.4
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    • pp.635-646
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    • 2010
  • This article focuses on Funology and a new classified application system based on concept of language and thought which are formed by body experience. It is defined by Funology Body as that. Funology Body is classifying and searching system which are consisted of a body, world (environment), and device tool. The body is sectioned by Brain, Eyes, Ears, Nose, Mouth, Hand, Torso, Feet, and Heart according as parts of the human body. This allows intuiting and experience searching as making classified system connected to the application relationship with concept of an each part of body. The Brain of the body is sub-classified by Book, Account, Business, Memory, Education, Search, and Aphorism to imply the application with thought. The Eyes take Video, Photography, and Broadcast for visibility. The Ears is categorized as Music, Instrument, Audio, and Radio for hearing. The Nose gets Perfume, Smell for olfactory sense. The Mouth is sectioned by Food, SNS, Chatting, Email, and Blog for eating and communication. The Hand sorts into Games, Kits, and Editing to handle, create, and play. The Torso is grouped by Health, Medical, Dance, Sport, Fashion, and Testyuorself related by protecting internal and meaning of the body core. The Feet is classified by Travel, Transportation, Map, and Outdoor for moving and concept of expanding the terrain. The Heart is consisted of Fear, Anger, Joy, Sadness, Acceptance, Disgust, Expectation, and Surprise for a human feeling. Beyond that, the World takes News, Time, Weather, Map, Fortune, and Shop, and Device tool gets Interface, Utilities. The Funology Body has a unique characteristic of giving intuitive and sensuous pleasure and reflection of users' attitude and taste for changing application flexibly.

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CO OBSERVATIONS OF A HIGH LATITUDE CLOUD MBM 40 WITH A HIGH RESOLUTION AUTOCORRELATOR

  • LEE YOUNGUNG;CHUNG HYUN SOO;KIM HYORYOUNG
    • Journal of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.97-103
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    • 2002
  • We have mapped 1 $deg^2$ region toward a high latitude cloud MBM 40 in the J = 1 - 0 transition of $^{12}CO$ and $^{13}CO$, using the 3 mm SIS receiver on the 14 m telescope at Taeduk Radio Astronomy Observatory. We used a high resolution autocorrelator to resolve extremely narrow CO linewidths of the molecular gas. Though the linewidth of the molecular gas is very narrow (FWHP < 1 km $s^{-1}$ ), it is found that there is an evident velocity difference between the middle upper part and the lower part of the cloud. Their spectra for both of $^{12}CO$ and $^{13}CO$ show blue wings, and the position-velocity map shows clear velocity difference of 0.4 km $s^{-1}$ between two parts. The mean velocity of the cloud is 3.1 km $s^{-1}$. It is also found that the linewidths at the blueshifted region are broader than those of the rest of the cloud. We confirmed that the visual extinction is less than 3 magnitude, and the molecular gas is translucent. We discussed three mass estimates, and took a mass of 17 solar masses from CO integrated intensity using a conversion factor $2.3 {\times} 10^{20} cm^{-2} (K\;km s^{-1})^{-1}$. Spatial coincidence and close morphological similarity is found between the CO emission and dust far-infrared (FIR) emission. The ratio between the 100 f.Lm intensity and CO integrated intensity of MBM 40 is 0.7 (MJy/sr)/(K km $s^{-1}$), which is larger than those of dark clouds, but much smaller than those of GMCs. The low ratio found for MBM 40 probably results from the absence of internal heating sources, or significant nearby external heating sources.

cdma2000 Physical Layer: An overview

  • Willenegger, Serge
    • Journal of Communications and Networks
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    • v.2 no.1
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    • pp.5-17
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    • 2000
  • cdma2000 offers several enhancement as compared to TIA/EIA-95, although it remains fully compatible with TIA/EIA-95 systems and allows for a smooth migration from one to the other-Major new capability include:1)connectivity to GSM-MAP in addition to IP and IS-41 networks; 2) new layering with new LAC and MAC architectures for improved service multiplexing and QoS management and efficient use of radio resource ;3) new bands and band widths of operation in support of various operator need and constraints, as well as desire for a smooth and progressive migration to cdma 2000; and 4) flexible channel structure in support of multiple services with various QoS and variable transmission rates at up to 1 Mbps per channel and 2 Mbps per user. Given the phenomenal success of wireless services and desire for higher rate wireless services. improved spectrum efficiency was a major design goal in the elaboration of cdma2000. Major capacity enhancing features include; 1) turbo coding for data transmission: 2)fast forward link power control :3) forward link transmit diversity; 4) support of directive antenna transmission techniques; 5) coherent reverse link structure; and 6) enhanced access channel operation. As users increasingly rely on their cell phone at work and at home for voice and data exchange, the stand-by time and operation-time are essential parameters that can influence customer's satisfaction and service utilization. Another major goal of cdma2000 was therefore to enable manufacturers to further optimize power utilization in the terminal. Major battery life enhancing features include; 1) improved reverse link performance (i.e., reduced transmit power per information bit; 2) new common channel structure and operation ;3) quick paging channel operation; 4) reverse link gated transmission ; and 5) new MAC stated for efficient and ubiquitous idle time idle time operation. this article provides additional details on those enhancements. The intent is not to duplicate the detailed cdma2000 radio access network specification, but rather to provide some background on the new features of cdma2000 and on the qualitative improvements as compared to the TIA/EIA-95 based systems. The article is focused on the physical layer structure and associated procedures. It therefore does not cover the MAC, LAC, radio resource management [1], or any other signaling protocols in any detail. We assume some familiarity with the basic CDMA concepts used in TIA/EIA-95.

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Realistic and Efficient Radio Propagation Model for V2X Communications

  • Khokhar, Rashid Hafeez;Zia, Tanveer;Ghafoor, Kayhan Zrar;Lloret, Jaime;Shiraz, Muhammad
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.8
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    • pp.1933-1954
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    • 2013
  • Multiple wireless devices are being widely deployed in Intelligent Transportation System (ITS) services on the road to establish end-to-end connection between vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) networks. Vehicular ad hoc networks (VANETs) play an important role in supporting V2V and V2I communications (also called V2X communications) in a variety of urban environments with distinct topological characteristics. In fact, obstacles such as big buildings, moving vehicles, trees, advertisement boards, traffic lights, etc. may block the radio signals in V2X communications. Their impact has been neglected in VANET research. In this paper, we present a realistic and efficient radio propagation model to handle different sizes of static and moving obstacles for V2X communications. In the proposed model, buildings and large moving vehicles are modeled as static and moving obstacles, and taken into account their impact on the packet reception rate, Line-of-sight (LOS) obstruction, and received signal power. We use unsymmetrical city map which has many dead-end roads and open faces. Each dead-end road and open faces are joined to the nearest edge making a polygon to model realistic obstacles. The simulation results of proposed model demonstrates better performance compared to some existing models, that shows proposed model can reflect more realistic simulation environments.

Design of complex IPS system to improve positioning accuracy (측위 정확도 향상을 위한 복합 IPS 시스템 설계)

  • Lee, Hyoun-sup;Kim, Jin-deog
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.10
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    • pp.1917-1922
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    • 2017
  • WPS(Wifi Positioning System) conducts positioning using wireless signals scattered in real world. This process is divided into two stages: Construction Stage that collects information on wireless signals for determining location and constructs a radio map and Positioning Stage that compares the constructed information with the collected information on wireless signals. WPS lowers the accuracy of positioning if changes occur to the collected signals during positioning. PDR have recently been studied. IPS is a system designed to find out the final destination by analyzing pedestrian's no. of gait, travel range, and direction through inertial sensors. If the positioning results of WPS appear in more than two locations, it can be thought as the problem of positioning accuracy. In some cases, problems occur. In this respect, this study analyzes the situations in which the problem as mentioned above occurs and proposes a system to solve this problem through PDR.

Sensor Fusion for Seamless Localization using Mobile Device Data (센서 융합 기반의 실내외 연속 위치 인식)

  • Kim, Jung-yee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.10
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    • pp.1994-2000
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    • 2016
  • Technology that can determine the location of individuals is required in a variety of applications such as location based control, a personalized advertising. Missing-child prevention and support for field trips, and applications such as push events based on the user's location is endless. In particular, the technology that can determine the location without interruption in the indoor and outdoor spaces have been studied a lot recently. Because emphasizing on accuracy of the positioning, many conventional research have constraints such as using of additional sensing devices or special mounting devices. The algorithm proposed in this paper has the purpose of performing the positioning only with standard equipment of the smart phone that has the most users. In this paper, sensor Fusion with GPS, WiFi Radio Map, Accelerometer sensor and Particle Filter algorithm is designed and implemented. Experimental results of this algorithm shows superior performance than the other compared algorithm. This could confirm the possibility of using proposed algorithm on actual environment.

Stationary Emitter Geolocation Based on NLSE Using LOBs Considering the Earth's Curvature (지구 곡률이 고려된 LOB를 이용하는 NLSE 기반의 고정형 신호원 위치추정)

  • Park, Byungkoo;Kim, Sangwon;Ahn, Jaemin;Kim, Youngmin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.3
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    • pp.661-672
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    • 2017
  • This paper introduces the NLSE(Nonlinear Least Squared Estimator) using curved LOBs(Line Of Bearings) considering the earth curvature based on sphere to avoid the map conversion distortion and minimize the estimation error. This paper suggests a method improving a performance of the NLSE using curved LOBs by using an ellipsoid model. The analysis of the simulation results shows that the NLSE using curved LOBs has better performance than the conventional triangulation method and can improve its performance using a suggested method.

Channel Modeling and RF Performance Verification in mmWave Bands Based on NS-3 (NS-3 기반의 mmWave 대역 채널 모델링 및 RF 성능 검증)

  • Seung-Min Lee;Jun-Seok Seo;Hong-Je Jang;Myung-Ryul Choi
    • Journal of IKEEE
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    • v.27 no.4
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    • pp.650-656
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    • 2023
  • This paper implements a channel model for mmWave bands using an NS-3-based 5G system-level simulator and analyzes the reliability and validity of the implemented model through RF performance verification. The channel model for RF performance verification in the mmWave bands consider parameters such as characteristics defined in 3GPP TR 38.901, beam-forming, antenna configuration, scenarios, among others. Furthermore, the simulation results verify compliance within the ranges permitted by the 3GPP standards and verify reliability in indoor environmental scenarios by exploiting the Radio Environment Map (REM). Therefore, the channel model implemented in this study is applicable to the actual design and establishment of 5G networks, presenting a method to evaluate and validate RF performance by adjusting various parameters.

Fingerprint-Based Indoor Logistics Location Tracking System (핑거프린트에 기반한 실내 물류 위치추적 시스템)

  • Kim, Doan;Park, Sunghyun;Jung, Hoekyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.7
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    • pp.898-903
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    • 2020
  • In this paper, we propose an indoor logistic tracking system that identifies the location and inventory of the logistics in the room based on fingerprints. Through this, we constructed the actual infrastructure of the logistics center and designed and implemented the logistics management system. The proposed system collects the signal strength through the location terminal and generates the signal map to locate the goods. The location terminal is composed of a UHF RFID reader and a wireless LAN card, reads the peripheral RFID signal and the signal of the wireless AP, and transmits it to the web server. The web server processes the signal received from the location terminal and stores it in the database, and the user uses the data to produce the signal map. The proposed system combines UHF RFID with existing fingerprinting method to improve performance in the environment of querying multiple objects.