IWAIT January 6-8, Pukyong National University, Busan, Korea International Workshop on Advanced Image Technology
|
|
- Cory Watson
- 5 years ago
- Views:
Transcription
1 ISBN IWAIT International Workshop on Advanced Image Technology January 6-8, 2016 Pukyong National University, Busan, Korea Organized by The Korean Institute of Broadcast and Media Engineers (KIBME), Korea Co-Organized by Institute of Electronics Information and Communication Engineers (IEICE), Japan Institute of Image Information and Television Engineers (ITE), Japan Japanese Society of Precision Engineering (JSPE-IAIP), Japan National Science Council (NSC), Taiwan IEEE Broadcast Technology Society, Seoul Chapter IEEE Consumer Electronics Society, Seoul Chapter Electronics and Telecommunications Research Institute (ETRI), Korea Supported by LG Electronics, JINMYUNG BROADCAST, MPEG Forum The Korean Federation of Science and Technology Societies (KOFST) Busan Tourism Organization (BTO), Any Future Technology (AFT)
2 TECHNICAL PROGRAM P.2C-5 View synthesis using homography transformation for 360 VR service Gun Bang, Gwhang soon Lee ETRI, Korea P.2C-6 Multiple Sensorial Media Application Format Sang-Kyun Kim, Jung Yup Oh Myongji University, Korea P.2C-7 Standardization of Media-centric Internet of Things Sang-Kyun Kim Myongji Unversity, Korea P.2C-8 Near-Duplicate Video Copy Detection with Multi-Modal Video Signature Matching Jun-Tae Lee, Kyung-Rae Kim, Won-Dong Jang, Chang-Su Kim Korea University, Korea P.2C-9 BLE Beacon-based Position Tracking System in Android Platform Dong-Kyu Choi, Joong-Hwa Jung, Sang-Il Choi, Seok-Joo Koh Kyungpook National University, Korea P.2C-10 Implementation of CoAP/6LoWPAN over BLE Network for IoT Services Cheol-Min Kim, Hyung-Woo Kang, Seok-Joo Koh Kyungpook National University, Korea P.2C-11 LABORATORY MEASUREMENT TO PROVIDE THRESHOLD OF VISIBILITY FOR TERRESTRIAL 4K-UHDTV BROADCASTING BASED ON HEVC OVER DVB-T2 IN AWGN CHANNEL Sungho Jeon, Junghyun Kim, Jaekwon Lee, Sanghun Kim, Jeong-Deok Kim, Young-Woo Suh, Zungkon Yim KBS, Korea P.2C-12 RGB-D Image Segmenation Based on Random Walk with Restart Se-Ho Lee, Won-Dong Jang, Chang-Su Kim Korea University, Korea P.2C-13 Getting Higher Performance Using a Two-Layer Extreme Learning Machine Junhyuk Hyun, Jeonghyun Baek, Jisu Kim, Peyman Hosseinzadeh Kassani, Euntai Kim Yonsei University, Korea P.2C-14 Implementation of Integrated multi-media measurement and monitoring system Young-Woo Suh, Junghyun Kim, Sungho Jeon, Zungkon Yim, Sung-Choon Park KBS, Korea P.2C-15 Relaxation Based Matching of SIFT Keypoints Clustered by Gradients and Location Sunmin Lee, Yong Cheol Kim University of Seoul, Korea P.2C-16 Toward 3D Object Tracking without Jittering Minseok Kang, Jungsik Park, Jong-Il Park Hanyang University, Korea P.2C-17 The optimal bilateral remote control system under disaster environment Sun Lim, Young Wook Kim KETI, Korea P.2C-18 Multiple Player Tracking in Indoor Sports with Multi-cameras Yookyung Kim, Gi-Mun Um, Kwang-Yong Kim, Kee-Seong Cho, Hyungmin Kim*, Jong-Il Park* ETRI, *Hanyang University, Korea P.2C-19 Human Gait Prediction method using Microsoft Kinect Junghwan Kim, Doyoung Kim, Inwoong Lee, Jongyoo Kim, Heeseok Oh, Sanghoon Lee Yonsei University, Korea P.2C-20 Copyright Protection and Compact- and Secure-Transmission of Diagnosed Fundus Images Wannida SAE-TANG King Mongkut s University of Technology, Thailand IWAIT
3 BLE Beacon-based Position Tracking System in Android Platform Dong-Kyu Choi, Joong-Hwa Jung, Sang-Il Choi, Seok-Joo Koh* School of Computer Science and Engineering Kyungpook National University Daegu, Korea Abstract To provide various convenient services using smartphone, the interests in Bluetooth or Bluetooth Low Energy (BLE) have been increased. One of the useful functions using Bluetooth Beacon is user position estimation with the distance measurement. However, it is difficult to measure the actual distance and position in a simple way, because Bluetooth Beacon is vulnerable to interference. To overcome this problem, we proposes two optimized distance measurement schemes: the average distance scheme and the prune off scheme. In each proposed scheme, we calculates the average distance using all or some measured distance between Bluetooth Beacon and user and uses the calculated average distance as a distance value. Then, based on three distance values, we can obtain the user position estimated by three candidate schemes. From the performance analysis, we compare three candidate schemes in terms of accuracy of position estimation. As a result, we can see that the two proposed schemes show better accuracy than general scheme and prune off scheme has the best performance. Keywords Bluetooth Beacon, Positioning Tracking System, Bluetooth 4.0, BLE, Android I. INTRODUCTION With the growth of smartphone services, the interests in services and technologies using Bluetooth or Bluetooth Low Energy (BLE) [1-2] have been increased. The Bluetooth Beacon [3] using Bluetooth 4.0 is a device to provide shortrange wireless communication less than 50 meters, and it can solve several limitations of short-range wireless communication protocol such as NFC [4], GPS [5], and Wi-Fi [6]. The Bluetooth Beacon can be used in various indoor or outdoor environment, and also it can overcome the radio shadow area problem of GPS. In addition, the Bluetooth Beacon supports BLE, and thus it can reduce the power consumption and solve the high power consumption problem of Wi-Fi. Many related products have been developed, such as ibeacon of Apple [7], Eddystone of Google [8], Paypal beacon of Paypal, and etc. However, most of existing works have focused on the development of product. There is no study on the services to provide convenience by utilizing the Bluetooth Beacon. One of the useful functions of Bluetooth Beacon is to measure distance between Bluetooth Beacon and mobile device. For the distance measurement service using Bluetooth Beacon, it transmits the Bluetooth signals periodically. After that, several smartphones can receive the Bluetooth signal at the same time. On the reception of Bluetooth signal, smartphone sends the information, which is the Unique User Identifier (UUID) of Bluetooth Beacons and the measured distance to a server. To calculate the location of a user, at least three Bluetooth Beacons are required to uses trilateration. Then, the server sends the coordinates image resources and positions to the smartphone. However, there are some difficulties to measure distance using Bluetooth Beacon due to measurement error. If the measurement error is continuously occurred, it is hard to get the exact position of the user. To overcome this problem, in this paper, we proposes two optimized distance measurement schemes: the average distance scheme and the prune off scheme. In the average distance scheme, the accurate data is calculated by average of all measured values in each Bluetooth Beacon. By using an average of the all measured values, it is possible to reduce the measurement error. On the other hand, in the prune off scheme, the accurate data is calculated by average of selected some values. In this scheme, we checks the distribution chart and remove the values of both end sides. Then, we calculate the average using remained values. By discarding some error values, it can improve the accuracy of the calculated value. This paper organized as follow. Section II briefly introduce the measuring method using Bluetooth Beacon. Section III reviews general positioning tracking system using Bluetooth Beacon. In Section IV, we presents two proposed schemes. Section V analyzes and compares three candidate schemes. Section VI concludes this paper. II. MEASURING METHOD USING BLUETOOTH BEACON A. Distance Measurement Using Bluetooth Beacon To estimate a distance between smartphone and Bluetooth Beacon, the signal level and reference level of beacon are
4 needed. In the case of signal level, Bluetooth Beacon provides a RSSI (Received Signal Strength Indication) [9] value as a signal level. For example, we assume that packets advertised by Bluetooth Beacon are arrives with the -65dBm signal level calibration, and the output of the reference level is -59dBm. Since the signal level of -65dBm is weaker than -59dBm, the Bluetooth Beacon is likely to be at a distance greater than 1 meter. Therefore, we can calculate the distance between smartphone and Bluetooth Beacon using two values, which is RSSI and reference level. Fig. 1 shows the distance estimation function used in Android Beacon Library [10]. III. GENERAL POSITIONING TRACKING SCHEME In the general positioning tracking scheme, a smartphone receives only one distance value between user and Bluetooth Beacon at a time. Although various measurement errors can be occurred, there is no special error correction procedures. Fig. 1. Distance estimation function used in Android beacon library B. Position Measurement Using Bluetooth Beacon To estimate a position of user, the most commonly used scheme is triangulation algorithm. In this algorithm, the position is calculated by three different point. First, it measure the distance between the user and three different points. Then, it draws circles with a radius, which is the distance between the user and itself. At this time, the intersection of three circles is the position of user. However, if Bluetooth Beacons are used as a distance measurement method, there is no intersection of three different circles due to measurement error. So, in this paper, additional calculations are added. First, we draws three straight line using each two intersections of two circles. Then, there is one intersection among three lines. In this paper, we assumed that this intersection is estimated position of user. Fig. 2 shows the modified position measurement algorithm to considering the measurement error of Bluetooth Beacon. Fig. 3. Example of measured data in general positioning tracking system Fig. 3 shows the example of measured data in general positioning tracking system. In this figure, we set the distance between Bluetooth Beacon and user to 8-meters and measured 50 times. According to the figure, it is shown that the measured distance is very irregular due to measurement error of Bluetooth Beacon. In addition, this incorrect distance value has a bad effect on the positioning tracking system. Fig. 4 shows the estimated user position with incorrect distance values. Fig. 4. Example of estimated user position with incorrect distance values Fig. 2. Modified position measurement algorithm In the figure, the estimated position of user (red star) is so far from actual position of user (yellow star). As mentioned above, it is because the position estimated by each distance between user and Bluetooth Beacon that contains the measurement error. To provide an effective positioning tracking service using Bluetooth Beacon, the error of measurement error should be solved.
5 IV. PROPOSED POSITIONING TRACKING SCHEMES To overcome the measurement error of Bluetooth Beacon, we focus on the distribution of the measured values. Fig. 5 shows the distribution of the measured values of Bluetooth Beacon. In the figure, we set the distance between Bluetooth Beacon and mobile device to 8-meters and measure repeatedly 2000 times. B. The Prune Off Scheme In the prune off scheme, we measure the distance between Bluetooth Beacon and user several times at a time and draw distribution chart. In this paper, we set the number of distance measurements to 20. Then, we select the most gathered interval and remove other samples, which is within other intervals. In this scheme, the distance between Bluetooth Beacon and user is average value of measured distance in selected intervals. Fig. 7 shows the flow diagram of prune off scheme. Fig. 5. Distribution of the measured values of Bluetooth Beacon According to the figure, it is shown that the frequency of a value similar with actual distance is higher than other incorrect value. In addition, the measurement error is greater, the probability of occurrence is decreased. Based on this analysis, we proposes two Bluetooth Beacon-based positioning tracking schemes: average distance scheme and prune off scheme. A. The Average Distance Scheme In the average distance scheme, we measure the distance between Bluetooth Beacon and user several times at a time and calculate an average distance. In this paper, we set the number of distance measurements to 30. Then we set the average distance as a distance between Bluetooth Beacon and user. Fig. 6 shows the example of estimated distance using average distance scheme. Fig. 7. Flow diagram of prune off scheme First, in this scheme, it extracts twenty-measured distance between Bluetooth Beacon and user at a time. Then, it displays all measured distance value in the distribution chart. In this case, we assume that the interval of distribution chart is 0.5- meters. When the distribution chart is completed, it counts the number of values in each interval and selects an interval that has the biggest value. Then, these distance values in selected interval are stored at selected distance. Additionally, distance values nearby selected interval are stored at selected distance. After that, it calculates the average value using selected distance values and defines the average value as a distance value. Fig. 6. Exmaple of estimated distance using average distance scheme In the figure, we set the distance between Bluetooth Beacon and user to 8-meters and measured 50 times using average distance scheme. As a result, we can see that each estimated distance using average distance scheme is similar to the actual distance. It is because the distribution of measured distance is similar to normal distribution and average calculating operation offsets by large and small measurement errors. However, it still has a tendency in which the measured distance is little shorter than the actual distance. V. PERFORMANCE ANALYSIS For the performance analysis, we made up the experimental model with smartphone and three Bluetooth Beacons. Each distance between Bluetooth Beacon and smartphone is set to 8- meters. In other words, the smartphone is located at (0, 0) and three Bluetooth Beacons are located at (8, 0), (0, 8), and (-8, 0) respectively in two-dimensional plane. In this experimental environment, we measure and estimate three distances between each Bluetooth Beacon and smartphone. Then, based on three distances, we estimate the coordinate of smartphone and verify the accuracy of three candidate schemes by comparing the actual and estimated coordinates.
6 Fig. 8. Measured and estimated distance of three candidate schemes Fig. 8 shows the measured and estimated distance of three candidate schemes. In this figure, we can see that the general scheme has a large variation because of measuring error due to interference. On the other hand, the variations of two proposed schemes are smaller than general scheme. This is because the occurred distance error processing by the averaging. In addition, the prune off scheme can remove some large distance error value using distribution chart. Then, it calculates an average distance using only reliable distance values. As a result, the prune off scheme shows best accuracy among three candidate schemes. VI. COCLUSION In this paper, we propose two optimized distance measurement schemes: the average distance scheme and the prune off scheme. In the average distance scheme, the accurate data is calculated by average of all measured values in each Bluetooth Beacon. On the other hand, in the prune off scheme, the accurate data is calculated by average of selected some values. In this scheme, we will check the distribution of the measured values and remove the values of both end sides. Then, we calculate the average using remained values. From the performance analysis, we can see that the proposed two optimized distance schemes show better accuracy than general positioning tracking scheme because of processing of measurement error. However, in case of the prune off scheme, it reduces the number of sample distance value compared with the average distance scheme by removing some large measurement error values using distribution chart. So, it can reduce the overhead of sample distance measurement. Therefore, we can see that the prune off scheme has best performance and accuracy among three candidate schemes. ACKNOWLEDGMENT This research was supported by the MSIP (Ministry of Science, ICT and Future Planning), Korea, under the SW- Centered University Program (IITP-2015-R ) supervised by the IITP (Institute for Information& communications Technology Promotion) and by the BK21 Plus project (SW Human Resource Development Program for Supporting Smart Life) funded by the Ministry of Education, School of Computer Science and Engineering, Kyungpook National University, Korea (21A ). Fig. 9. Estimated user position of three candidate schemes Fig. 9 shows the position of the user on the twodimensional coordinates. As mentioned above, the general scheme has biggest distribution and worst accuracy, because it does not consider the measurement error of Bluetooth Beacon. On the other hand, two proposed scheme shows similar distribution and accuracy because of the distance error processing by using calculated average value. Comparing the two proposed schemes, the prune off scheme has lower number of extracted sampling distance value because of removal of some large measurement error values using distribution chart. As a result, despite the lower number of sample distance value, the prune off scheme can have similar result with average distance scheme and it means that the prune off scheme has the best performance. REFERENCES [1] Jin-Shyan Lee, A comparative study of wireless protocols: bluetooth, uwb, zigbee and wi-fi, 33rd Annual Conference of the IEEE, November [2] Gomez, C.; Oller, J.; Paradells, J. Overview and Evaluation of Bluetooth Low Energy: An Emerging Low-Power Wireless Technology, Sensors 2012, 12, [3] JoaKim Lindh, Bluetooth low energe beacons, in Texas Instruments, January 2015 [4] Near field communication, [5] Simon D. P. Williams, et al., Error analysis of continuous GPS position time series, Journal of geophysical research Vol.109 Issue B3, March 2004 [6] Andrei Croitoru, Costin Raiciu and Dragos Niculescu, Wi-fi mobility without fast handover, IETF-RFC [7] Andy Cavallini, ibeacon Bible 2.0, [8] Google Developers, [9] M. Sugano, T. Kawazoe, Y. Ohta, and M. Murata, Indoor localization system using RSSI measurement of wireless sensor network based on zigbee standard, Wireless and Optical Communication MultiConference, July 2006 [10] Android-beacon library,
TAC Reconfiguration for Paging Optimization in LTE-Based Mobile Communication Systems
TAC Reconfiguration for Paging Optimization in LTE-Based Mobile Communication Systems Hyung-Woo Kang 1, Seok-Joo Koh 1,*, Sang-Kyu Lim 2, and Tae-Gyu Kang 2 1 School of Computer Science and Engineering,
More informationIoT-Aided Indoor Positioning based on Fingerprinting
IoT-Aided Indoor Positioning based on Fingerprinting Rashmi Sharan Sinha, Jingjun Chen Graduate Students, Division of Electronics and Electrical Engineering, Dongguk University-Seoul, Republic of Korea.
More informationComparison of RSSI-Based Indoor Localization for Smart Buildings with Internet of Things
Comparison of RSSI-Based Indoor Localization for Smart Buildings with Internet of Things Sebastian Sadowski and Petros Spachos, School of Engineering, University of Guelph, Guelph, ON, N1G 2W1, Canada
More informationEnhanced indoor localization using GPS information
Enhanced indoor localization using GPS information Taegyung Oh, Yujin Kim, Seung Yeob Nam Dept. of information and Communication Engineering Yeongnam University Gyeong-san, Korea a49094909@ynu.ac.kr, swyj90486@nate.com,
More informationDesign of MDM System using BLE Beacon and Extended Kalman Filter
Indian Journal of Science and Technology, Vol 9(29), DOI: 10.17485/ijst/2016/v9i29/94761, August 2016 ISSN (Print) : 0974-6846 ISSN (Online) : 0974-5645 Design of MDM System using BLE Beacon and Extended
More informationPerformance Evaluation of Beacons for Indoor Localization in Smart Buildings
Performance Evaluation of Beacons for Indoor Localization in Smart Buildings Andrew Mackey, mackeya@uoguelph.ca Petros Spachos, petros@uoguelph.ca University of Guelph, School of Engineering 1 Agenda The
More information(JBE Vol. 17, No. 6, November 2012) a), A Study on the AM/FM Digital Radio for Practical Use Based on DRM and DRM+
(JBE Vol 17 No 6 November 2012) (Special Paper) 17 6 2012 11 (JBE Vol 17 No 6 November 2012) http://dxdoiorg/105909/jbe2012176990 ISSN 1226-7953(Print) DRM / a) b) A Study on the / Digital Radio for Practical
More informationThe Seamless Localization System for Interworking in Indoor and Outdoor Environments
W 12 The Seamless Localization System for Interworking in Indoor and Outdoor Environments Dong Myung Lee 1 1. Dept. of Computer Engineering, Tongmyong University; 428, Sinseon-ro, Namgu, Busan 48520, Republic
More informationThree-dimensional positioning system using Bluetooth low-energy beacons
Special Issue Three-dimensional positioning system using Bluetooth low-energy beacons International Journal of Distributed Sensor Networks 016, Vol. 1(10) Ó The Author(s) 016 DOI: 10.1177/155014771667170
More informationA Simple Smart Shopping Application Using Android Based Bluetooth Beacons (IoT)
Advances in Wireless and Mobile Communications. ISSN 0973-6972 Volume 10, Number 5 (2017), pp. 885-890 Research India Publications http://www.ripublication.com A Simple Smart Shopping Application Using
More informationIoT. Indoor Positioning with BLE Beacons. Author: Uday Agarwal
IoT Indoor Positioning with BLE Beacons Author: Uday Agarwal Contents Introduction 1 Bluetooth Low Energy and RSSI 2 Factors Affecting RSSI 3 Distance Calculation 4 Approach to Indoor Positioning 5 Zone
More informationImmersive Real Acting Space with Gesture Tracking Sensors
, pp.1-6 http://dx.doi.org/10.14257/astl.2013.39.01 Immersive Real Acting Space with Gesture Tracking Sensors Yoon-Seok Choi 1, Soonchul Jung 2, Jin-Sung Choi 3, Bon-Ki Koo 4 and Won-Hyung Lee 1* 1,2,3,4
More informationA Study of Optimal Spatial Partition Size and Field of View in Massively Multiplayer Online Game Server
A Study of Optimal Spatial Partition Size and Field of View in Massively Multiplayer Online Game Server Youngsik Kim * * Department of Game and Multimedia Engineering, Korea Polytechnic University, Republic
More informationDesign of Traffic Flow Simulation System to Minimize Intersection Waiting Time
Design of Traffic Flow Simulation System to Minimize Intersection Waiting Time Jang, Seung-Ju Department of Computer Engineering, Dongeui University Abstract This paper designs a traffic simulation system
More informationIntroduction to Mobile Sensing Technology
Introduction to Mobile Sensing Technology Kleomenis Katevas k.katevas@qmul.ac.uk https://minoskt.github.io Image by CRCA / CNRS / University of Toulouse In this talk What is Mobile Sensing? Sensor data,
More informationDesign and Implementation of Distress Prevention System using a Beacon
Design and Implementation of Distress Prevention System using a Beacon Imsu Lee 1, Kyeonhoon Kwak 1, Jeonghyun Lee 1, Sangwoong Kim 1, Daehan Son 1, Eunju Park 1 and Hankyu Lim 1.a 1 Department of Multimedia
More informationIndoor Location System with Wi-Fi and Alternative Cellular Network Signal
, pp. 59-70 http://dx.doi.org/10.14257/ijmue.2015.10.3.06 Indoor Location System with Wi-Fi and Alternative Cellular Network Signal Md Arafin Mahamud 1 and Mahfuzulhoq Chowdhury 1 1 Dept. of Computer Science
More informationPower (mw) DNL/INL (LSB) 200k / / /
동부하이텍공정 IP LIST 2010. 07. 25 서강대학교집적회로설계연구실 IP fsample (MS/s) VDD (V) Power (mw) / (LSB) Area (mm 2 ) Process (um) Comments [1] 12-bit ADC [2] 12-bit ADC [3] 10-bit ADC [4] 15-bit ADC [5] 13-bit ADC 200k
More informationAvailable online at ScienceDirect. Procedia Computer Science 52 (2015 )
Available online at www.sciencedirect.com ScienceDirect Procedia Computer Science 52 (2015 ) 1083 1088 The 5th International Symposium on Internet of Ubiquitous and Pervasive Things (IUPT) Measuring a
More informationMOBILE COMPUTING 1/29/18. Cellular Positioning: Cell ID. Cellular Positioning - Cell ID with TA. CSE 40814/60814 Spring 2018
MOBILE COMPUTING CSE 40814/60814 Spring 2018 Cellular Positioning: Cell ID Open-source database of cell IDs: opencellid.org Cellular Positioning - Cell ID with TA TA: Timing Advance (time a signal takes
More informationAutomatic Generation of BLE Beacon Applications. Using Service Specifications
Contemporary Engineering Sciences, Vol. 9, 2016, no. 19, 925-932 HIKARI Ltd, www.m-hikari.com http://dx.doi.org/10.12988/ces.2016.6694 Automatic Generation of BLE Beacon Applications Using Service Specifications
More informationEfficiency Analysis of the Smart Controller Switch System using RF Communication for Energy Saving
Vol.133 (Information Technology and Computer Science 2016), pp.39-44 http://dx.doi.org/10.14257/astl.2016. Efficiency Analysis of the Smart Controller Switch System using RF Communication for Energy Saving
More informationEnhanced Indoor Positioning Method Using RSSI Log Model Based on IEEE s Mesh Network
International Global Navigation Satellite Systems Society IGNSS Symposium 2015 Outrigger Gold Coast, Australia 14-16 July, 2015 Enhanced Indoor Positioning Method Using RSSI Log Model Based on IEEE 802.11s
More informationEnhanced Positioning Method using WLAN RSSI Measurements considering Dilution of Precision of AP Configuration
Enhanced Positioning Method using WLAN RSSI Measurements considering Dilution of Precision of AP Configuration Cong Zou, A Sol Kim, Jun Gyu Hwang, Joon Goo Park Graduate School of Electrical Engineering
More informationDesign of Intelligent Blind Control System to Save Lighting Energy and Prevent Glare
, pp.541-545 http://dx.doi.org/10.14257/astl.2015.1 Design of Intelligent Blind Control System to Save Lighting Energy and Prevent Glare Mi-Ae Yu 1, Hyeong-Seok Kim 1, Yang-Soo Kim 1, Won-Il Seo 1, Young-Ho
More informationInternational Journal of Scientific & Engineering Research Volume 8, Issue 5, May ISSN
International Journal of Scientific & Engineering Research Volume 8, Issue 5, May-2017 38 Attendance system using Beacon Technology 1 Varshini A, 2 Indhurekha S 1 UG Scholar, 2 Assistant Professor, Computer
More informationTwo-Stage Time Slot Reservation Multiple Access Scheme for Communication Collision Avoidance
, pp.171-176 http://dx.doi.org/10.14257/astl.2016.137.33 Two-Stage Time Slot Reservation Multiple Access Scheme for Communication Collision Avoidance ByungBog Lee 1, Byeong-Cheol Choi 1 and Se-Jin Kim
More informationDEVELOPMENT OF A ROBOID COMPONENT FOR PLAYER/STAGE ROBOT SIMULATOR
Proceedings of IC-NIDC2009 DEVELOPMENT OF A ROBOID COMPONENT FOR PLAYER/STAGE ROBOT SIMULATOR Jun Won Lim 1, Sanghoon Lee 2,Il Hong Suh 1, and Kyung Jin Kim 3 1 Dept. Of Electronics and Computer Engineering,
More information1. Product Introduction FeasyBeacons are designed by Shenzhen Feasycom Technology Co., Ltd which has the typical models as below showing: Model FSC-BP
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, FeasyBeacon Getting Started Guide Version 2.5 Feasycom Online Technical Support: Skype: Feasycom Technical Support Direct Tel: 086 755 23062695 Email:
More informationResearch on an Economic Localization Approach
Computer and Information Science; Vol. 12, No. 1; 2019 ISSN 1913-8989 E-ISSN 1913-8997 Published by Canadian Center of Science and Education Research on an Economic Localization Approach 1 Yancheng Teachers
More informationImplementation of RSSI-Based 3D Indoor Localization using Wireless Sensor Networks Based on ZigBee Standard
Implementation of RSSI-Based 3D Indoor Localization using Wireless Sensor Networks Based on ZigBee Standard Thanapong Chuenurajit 1, DwiJoko Suroso 2, and Panarat Cherntanomwong 1 1 Department of Computer
More informationOptimized Indoor Positioning for static mode smart devices using BLE
Optimized Indoor Positioning for static mode smart devices using BLE Quang Huy Nguyen, Princy Johnson, Trung Thanh Nguyen and Martin Randles Faculty of Engineering and Technology, Liverpool John Moores
More informationExtended Gradient Predictor and Filter for Smoothing RSSI
Extended Gradient Predictor and Filter for Smoothing RSSI Fazli Subhan 1, Salman Ahmed 2 and Khalid Ashraf 3 1 Department of Information Technology and Engineering, National University of Modern Languages-NUML,
More informationACCURACY ANALYSIS OF DIFFERENTIAL DISTANCE CORRECTION USING BLUETOOTH LOW ENERGY TECHNOLOGY ON INDOOR POSITIONING SYSTEM
ACCURACY ANALYSIS OF DIFFERENTIAL DISTANCE CORRECTION USING BLUETOOTH LOW ENERGY TECHNOLOGY ON INDOOR POSITIONING SYSTEM Yun-Tzu, Kuo 1, Jhen-Kai, Liao 2, Kai-Wei, Chiang 3 1 Department of Geomatics, National
More informationResearch Article A Study of Smart Power Control Algorithm Using RF Communication in Smart Home Environment
Distributed Sensor Networks Volume 2013, Article ID 690902, 8 pages http://dx.doi.org/10.1155/2013/690902 Research Article A Study of Smart Power Control Algorithm Using RF Communication in Smart Home
More informationImproving Accuracy of FingerPrint DB with AP Connection States
Improving Accuracy of FingerPrint DB with AP Connection States Ilkyu Ha, Zhehao Zhang and Chonggun Kim 1 Department of Computer Engineering, Yeungnam Umiversity Kyungsan Kyungbuk 712-749, Republic of Korea
More informationOne-to-many data transmission for smart devices at close range
2016 IEEE First International Conference on Internet-of-Things Design and Implementation One-to-many data transmission for smart devices at close range Myoungbeom Chung Division of Computer Engineering
More informationADAPTIVE ESTIMATION AND PI LEARNING SPRING- RELAXATION TECHNIQUE FOR LOCATION ESTIMATION IN WIRELESS SENSOR NETWORKS
INTERNATIONAL JOURNAL ON SMART SENSING AND INTELLIGENT SYSTEMS VOL. 6, NO. 1, FEBRUARY 013 ADAPTIVE ESTIMATION AND PI LEARNING SPRING- RELAXATION TECHNIQUE FOR LOCATION ESTIMATION IN WIRELESS SENSOR NETWORKS
More informationDYNAMIC BLUETOOTH BEACONS FOR PEOPLE WITH DISABILITIES
DYNAMIC BLUETOOTH BEACONS FOR PEOPLE WITH DISABILITIES A journey from ibeacon to IoT beacons, InfinIT Summit 2017 BLUETOOTH BEACONS Short information sent by radio A few times per second Kind of radio
More informationA Study on Single Camera Based ANPR System for Improvement of Vehicle Number Plate Recognition on Multi-lane Roads
Invention Journal of Research Technology in Engineering & Management (IJRTEM) ISSN: 2455-3689 www.ijrtem.com Volume 2 Issue 1 ǁ January. 2018 ǁ PP 11-16 A Study on Single Camera Based ANPR System for Improvement
More informationSoC Design Conference
2 0 0 5 International Conference COEX Conference Center, Seoul, Korea October 20-21, 2005 I S O C C 2 0 0 5 I S O C C 2 International 0 0 5 http://www.isocc.org Conference Hosted by Technical Society IEEK
More informationA study on facility management application scenario of BIMGIS modeling data
International Journal of Engineering Science Invention ISSN (Online): 2319 6734, ISSN (Print): 2319 6726 Volume 6 Issue 11 November 2017 PP. 40-45 A study on facility management application scenario of
More informationAn Experiment Study for Time Synchronization Utilizing USRP and GNU Radio
GNU Radio Conference 2017, September 11-15th, San Diego, USA An Experiment Study for Time Synchronization Utilizing USRP and GNU Radio Won Jae Yoo, Kwang Ho Choi, JoonHoo Lim, La Woo Kim, Hyoungmin So
More informationII. EXPERIMENTAL SETUP
J. lnf. Commun. Converg. Eng. 1(3): 22-224, Sep. 212 Regular Paper Experimental Demonstration of 4 4 MIMO Wireless Visible Light Communication Using a Commercial CCD Image Sensor Sung-Man Kim * and Jong-Bae
More informationOccupancy Detection via ibeacon on Android Devices for Smart Building Management
Occupancy Detection via ibeacon on Android Devices for Smart Building Management Omitted for blind review Abstract Building heating, ventilation, and air conditioning (HVAC) systems are considered to be
More informationCSRmesh Beacon management and Asset Tracking Muhammad Ulislam Field Applications Engineer, Staff, Qualcomm Atheros, Inc.
CSRmesh Beacon management and Asset Tracking Muhammad Ulislam Field Applications Engineer, Staff, Qualcomm Atheros, Inc. CSRmesh Recap Bluetooth Mesh Introduction What is CSRmesh? A protocol that runs
More information324 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 2, APRIL 2006
324 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 34, NO. 2, APRIL 2006 Experimental Observation of Temperature- Dependent Characteristics for Temporal Dark Boundary Image Sticking in 42-in AC-PDP Jin-Won
More informationA Study on Distributed and Concentric Winding of Permanent Magnet Brushless AC Motor
Volume 118 No. 19 2018, 1805-1815 ISSN: 1311-8080 (printed version); ISSN: 1314-3395 (on-line version) url: http://www.ijpam.eu ijpam.eu A Study on Distributed and Concentric Winding of Permanent Magnet
More informationHardware-free Indoor Navigation for Smartphones
Hardware-free Indoor Navigation for Smartphones 1 Navigation product line 1996-2015 1996 1998 RTK OTF solution with accuracy 1 cm 8-channel software GPS receiver 2004 2007 Program prototype of Super-sensitive
More information2015 년 2 월 10 일 ( 화 )-12 일 ( 목 ), 인천송도컨벤시아. Chip Design Contest Room K ( )
Chip Design Contest Room K (102+103) 2015 년 2 월 11 일 ( 수 ) 09:00-17:20 CDC001 CDC002 CDC003 CDC004 CDC005 CDC006 CDC007 CDC008 Comparison between CMOS and Nano-Electromechanical (NEM) Switches Yong Jun
More informationReal Time Indoor Tracking System using Smartphones and Wi-Fi Technology
International Journal for Modern Trends in Science and Technology Volume: 03, Issue No: 08, August 2017 ISSN: 2455-3778 http://www.ijmtst.com Real Time Indoor Tracking System using Smartphones and Wi-Fi
More informationKAIST Master of Science in Electrical Engineering (GPA 4.02/4.3) Feb Feb. 2012
SEONGAH JEONG Work Address Information & Electronics Research Institute Korea Advanced Institute of Science and Technology () Daejeon, Rep. of Korea Tel:+82 42 350 7522, Cell:+82 10 3048 2111 Home Address
More informationA Bluetooth Smart Analyzer in ibeacon Networks
A Bluetooth Smart Analyzer in ibeacon Networks Maria Varsamou and Theodore Antonakopoulos University of Patras Department of Electrical and Computer Engineering Patras 26504, Greece e-mails: mtvars@upatras.gr
More informationSmart Parking Information System Exploiting Visible Light Communication
, pp.251-260 http://dx.doi.org/10.14257/ijsh.2014.8.1.26 Smart Parking Information System Exploiting Visible Light Communication Nammoon Kim, Changqiang Jing, Biao Zhou and Youngok Kim Department of Electronics
More informationPixie Location of Things Platform Introduction
Pixie Location of Things Platform Introduction Location of Things LoT Location of Things (LoT) is an Internet of Things (IoT) platform that differentiates itself on the inclusion of accurate location awareness,
More informationBeacon Indoor Navigation System. Group 14 Andre Compagno, EE. Josh Facchinello, CpE. Jonathan Mejias, EE. Pedro Perez, EE.
Beacon Indoor Navigation System Group 14 Andre Compagno, EE. Josh Facchinello, CpE. Jonathan Mejias, EE. Pedro Perez, EE. Motivation GPS technologies are not effective indoors Current indoor accessibility
More informationInformation gathering system based on BLE communication for bus information sharing
Information gathering system based on BLE communication for bus information sharing Katsuhiro Naito Department of Information Science, Aichi Institute of Technology, 1247 Yachigusa, Yakusa, Toyota, Aichi
More informationIndoor Positioning Technology Based on Multipath Effect Analysis Bing Xu1, a, Feng Hong2,b, Xingyuan Chen 3,c, Jin Zhang2,d, Shikai Shen1, e
3rd International Conference on Materials Engineering, Manufacturing Technology and Control (ICMEMTC 06) Indoor Positioning Technology Based on Multipath Effect Analysis Bing Xu, a, Feng Hong,b, Xingyuan
More informationA Local-Dimming LED BLU Driving Circuit for a 42-inch LCD TV
A Local-Dimming LED BLU Driving Circuit for a 42-inch LCD TV Yu-Cheol Park 1, Hee-Jun Kim 2, Back-Haeng Lee 2, Dong-Hyun Shin 3 1 Yu-Cheol Park Intelligent Vehicle Technology R&D Center, KATECH, Korea
More informationBTLE beacon for 8262 DECT handset Engineering Rules
BTLE beacon for 8262 DECT handset Engineering Rules 8AL90346ENAAed01 April 2017 Table of content 1. INTRODUCTION... 3 2. LIST OF ACRONYMS... 3 3. RECOMMENDED USE CASES... 3 3.1 BEACON EVENT... 3 3.2 LOCATION
More informationAn Efficient LSDM Lighting Control Logic Design for a Lighting Control System
ICACT Transactions on Advanced Communications Technology (TACT) Vol. 3, Issue 4, July 2014 494 An Efficient LSDM Lighting Control Logic Design for a Lighting Control System Sung-IL Hong, Chi-Ho Lin Schools
More informationIntelligent Robot Systems based on PDA for Home Automation Systems in Ubiquitous 279
Intelligent Robot Systems based on PDA for Home Automation Systems in Ubiquitous 279 18 X Intelligent Robot Systems based on PDA for Home Automation Systems in Ubiquitous In-Kyu Sa*, Ho Seok Ahn**, Yun
More informationImplementation of Augmented Reality System for Smartphone Advertisements
, pp.385-392 http://dx.doi.org/10.14257/ijmue.2014.9.2.39 Implementation of Augmented Reality System for Smartphone Advertisements Young-geun Kim and Won-jung Kim Department of Computer Science Sunchon
More informationIEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 32, NO. 6, DECEMBER
IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 32, NO. 6, DECEMBER 2004 2189 Experimental Observation of Image Sticking Phenomenon in AC Plasma Display Panel Heung-Sik Tae, Member, IEEE, Jin-Won Han, Sang-Hun
More informationSimulation Analysis for Performance Improvements of GNSS-based Positioning in a Road Environment
Simulation Analysis for Performance Improvements of GNSS-based Positioning in a Road Environment Nam-Hyeok Kim, Chi-Ho Park IT Convergence Division DGIST Daegu, S. Korea {nhkim, chpark}@dgist.ac.kr Soon
More information!"#$% Cognitive Radio Experimentation World. Project Deliverable D7.4.4 Showcase of experiment ready (Demonstrator)
Cognitive Radio Experimentation World!"#$% Project Deliverable Showcase of experiment ready (Demonstrator) Contractual date of delivery: 31-03-14 Actual date of delivery: 18-04-14 Beneficiaries: Lead beneficiary:
More informationCompany Information. Invisible Difference. Company Intro Technology Intro Product Intro Application
Company Information Invisible Difference Company Intro Technology Intro Product Intro Application Contents Company 02 Products 04 Demo 01 Technology 03 Exhibitions 05 01 Company Introduction UMAIN Inc.,
More informationMixed Reality technology applied research on railway sector
Mixed Reality technology applied research on railway sector Yong-Soo Song, Train Control Communication Lab, Korea Railroad Research Institute Uiwang si, Korea e-mail: adair@krri.re.kr Jong-Hyun Back, Train
More informationUsing Bluetooth Low Energy Beacons for Indoor Localization
International Journal of Intelligent Systems and Applications in Engineering Advanced Technology and Science ISSN:2147-67992147-6799 www.atscience.org/ijisae Original Research Paper Using Bluetooth Low
More informationOn Practical Selective Jamming of Bluetooth Low Energy Advertising
On Practical Selective Jamming of Bluetooth Low Energy Advertising S. Brauer, A. Zubow, S. Zehl, M. Roshandel, S. M. Sohi Technical University Berlin & Deutsche Telekom Labs Germany Outline Motivation,
More informationTogether or Alone: Detecting Group Mobility with Wireless Fingerprints
Together or Alone: Detecting Group Mobility with Wireless Fingerprints Gürkan SOLMAZ and Fang-Jing WU NEC Laboratories Europe, CSST group, Heidelberg, Germany 24 May 2017 This work has received funding
More informationA Study on the control Method of 3-Dimensional Space Application using KINECT System Jong-wook Kang, Dong-jun Seo, and Dong-seok Jung,
IJCSNS International Journal of Computer Science and Network Security, VOL.11 No.9, September 2011 55 A Study on the control Method of 3-Dimensional Space Application using KINECT System Jong-wook Kang,
More informationIndoor Positioning with a WLAN Access Point List on a Mobile Device
Indoor Positioning with a WLAN Access Point List on a Mobile Device Marion Hermersdorf, Nokia Research Center Helsinki, Finland Abstract This paper presents indoor positioning results based on the 802.11
More informationAnalysis of Multi-rate Wi-Fi Signals for FingerPrint Indoor Positioning
Analysis of Multi-rate Wi-Fi Signals for FingerPrint Indoor Positioning Chonggun Kim, Ilkyu Ha, Zhehao Zhang Department of Computer Engineering, Yeungnam Umiversity Kyungsan Kyungbuk 712-749, Republic
More informationCatalog
- 1 - Catalog 1. Description...- 3-2. Features...- 3-3. Application...- 3-4. Block Diagram...- 3-5. Electrical Characteristics... - 4-6. Operation... - 4-1) Power on Reset...- 4-2) Setting Mode... - 5-3)
More informationHow to Configure ibeacons in Jamf Pro
What is an ibeacon? ibeacon is a communication protocol developed by Apple on top of Bluetooth Smart technology. It allows developers to create mobile apps aware of location context provided by beacons.
More informationRealization of Multi-User Tangible Non-Glasses Mixed Reality Space
Indian Journal of Science and Technology, Vol 9(24), DOI: 10.17485/ijst/2016/v9i24/96161, June 2016 ISSN (Print) : 0974-6846 ISSN (Online) : 0974-5645 Realization of Multi-User Tangible Non-Glasses Mixed
More informationEstimation of Absolute Positioning of mobile robot using U-SAT
Estimation of Absolute Positioning of mobile robot using U-SAT Su Yong Kim 1, SooHong Park 2 1 Graduate student, Department of Mechanical Engineering, Pusan National University, KumJung Ku, Pusan 609-735,
More informationGENERAL INFORMATION SYNOPSIS. Sci-Fi, Thriller. Korean with English subtitles. Rating: JUNG Jae-young, CHOI Daniel, KIM Ok-bin
11 A.M. - Press Kit GENERAL INFORMATION Title: Genre: Language: Running Time: Rating: Director: Cast: Presented by: Produced by: Distributed by: 11 A.M. Sci-Fi, Thriller Korean with English subtitles 95
More informationDiCa: Distributed Tag Access with Collision-Avoidance among Mobile RFID Readers
DiCa: Distributed Tag Access with Collision-Avoidance among Mobile RFID Readers Kwang-il Hwang, Kyung-tae Kim, and Doo-seop Eom Department of Electronics and Computer Engineering, Korea University 5-1ga,
More informationVerification of Intelligent Planting Robot Arm Design Using Dynamics Analysis and Simulation Kee-Jin Park 1 *, Byeong-Soo Kim 1 and Jeong-Ho Yun 2
2016 International Conference on Sustainable Energy, Environment and Information Engineering (SEEIE 2016) ISBN: 978-1-60595-337-3 Verification of Intelligent Planting Robot Arm Design Using Dynamics Analysis
More informationGlobal Journal on Technology
Global Journal on Technology Vol 5 (2014) 73-77 Selected Paper of 4 th World Conference on Information Technology (WCIT-2013) Issues in Internet of Things for Wellness Human-care System Jae Sung Choi*,
More informationA Study to Improve the Public Data Management of the City of Busan
Indian Journal of Science and Technology, Vol 8(15), DOI: 10.17485/ijst/2015/v8i15/73047, July 2015 ISSN (Print) : 0974-6846 ISSN (Online) : 0974-5645 A Study to Improve the Public Data Management of the
More informationOFFICE WIRELESS NETWORK PERFORMANCE IMPROVEMENT BY CHANGING WIRELESS ROUTERS INSTALLMENT PATTERN AND RADIO CHANNEL SETTING
OFFICE WIRELESS NETWORK PERFORMANCE IMPROVEMENT BY CHANGING WIRELESS ROUTERS INSTALLMENT PATTERN AND RADIO CHANNEL SETTING 1 RATCHANEPORN PANTHAI, 2 SUWAT PATTARAMALAI 1,2 Electronic and Telecommunication
More informationBaccarat Magazine Ms. Karen Ting replaced Mr. Jill Triptree as Editor-In-Chief Ms. Venus Chan joined as Editorial Coordinator
PR Newswire s Media Research Department makes thousands of updates to the database of journalists and bloggers that underpins our Agility media targeting and distribution platform. Below is a sampling
More informationMulti-Resolution Estimation of Optical Flow on Vehicle Tracking under Unpredictable Environments
, pp.32-36 http://dx.doi.org/10.14257/astl.2016.129.07 Multi-Resolution Estimation of Optical Flow on Vehicle Tracking under Unpredictable Environments Viet Dung Do 1 and Dong-Min Woo 1 1 Department of
More informationPresented By Tsv. Presented By Tsv
We have made it easy for you to find a PDF Ebooks without any digging. And by having access to our ebooks online or by storing it on your computer, you have convenient answers with presented by tsv. To
More informationSPTF: Smart Photo-Tagging Framework on Smart Phones
, pp.123-132 http://dx.doi.org/10.14257/ijmue.2014.9.9.14 SPTF: Smart Photo-Tagging Framework on Smart Phones Hao Xu 1 and Hong-Ning Dai 2* and Walter Hon-Wai Lau 2 1 School of Computer Science and Engineering,
More informationERFS: Enhanced RSSI value Filtering Schema for Localization in Wireless Sensor Networks
ERFS: Enhanced RSSI value Filtering Schema for Localization in Wireless Sensor Networks Seung-chan Shin and Byung-rak Son and Won-geun Kim and Jung-gyu Kim Department of Information Communication Engineering,
More informationModified RWGH and Positive Noise Mitigation Schemes for TOA Geolocation in Indoor Multi-hop Wireless Networks
Modified RWGH and Positive Noise Mitigation Schemes for TOA Geolocation in Indoor Multi-hop Wireless Networks Young Min Ki, Jeong Woo Kim, Sang Rok Kim, and Dong Ku Kim Yonsei University, Dept. of Electrical
More informationOverview of the KBCSD
Overview of the KBCSD (Korea Business Council for Sustainable Development) 1405 Trade Tower, 511, Youngdong-daero, Gangnam-gu, Seoul Korea TEL: +82 2 6000 7660~9, Fax: +82 2 6000 7671, Email: master@kbcsd.or.kr,
More informationTHE IMPLEMENTATION OF INDOOR CHILD MONITORING SYSTEM USING TRILATERATION APPROACH
THE IMPLEMENTATION OF INDOOR CHILD MONITORING SYSTEM USING TRILATERATION APPROACH Normazatul Shakira Darmawati and Nurul Hazlina Noordin Faculty of Electrical & Electronics Engineering, Universiti Malaysia
More informationReducing Location Registration Cost in Mobile Cellular Networks
Reducing Location Registration Cost in Mobile Cellular Networks Ki Ho Seo and Jang Hyun Baek Mobility management is important in mobile cellular networks. In this study, we considered an enhanced location-based
More informationDevelopment of Wireless Module Test Equipment for Gas Safety Devices Performance
, pp.81-87 http://dx.doi.org/10.14257/astl.2017.146.16 Development of Wireless Module Test Equipment for Gas Safety Devices Performance Dong Seok Oh, Jeong Seok Oh and Jin Han Lee Institute of Gas Safety
More informationANALYSIS OF BLUETOOTH LOW ENERGY BEACONS IN INDOOR LOCALIZATION POLICY AND APPLICATION JERRY R. GUO THESIS
c 2018 Jerry R. Guo ANALYSIS OF BLUETOOTH LOW ENERGY BEACONS IN INDOOR LOCALIZATION POLICY AND APPLICATION BY JERRY R. GUO THESIS Submitted in partial fulfillment of the requirements for the degree of
More informationResume. Research Experience Research assistant of electron-beam lithography system in inter-university semiconductor research center SNU)
Resume Updated at Aug-08-2005 Name Kyung Rok Kim Date & place of birth Born on February 14, 1976 in Seoul, Republic of KOREA Present occupation Post-Doctoral Researcher Office address Room CISX-302, Center
More informationA Study on Laser Based Vision System for Inspection Height of Structural Adhesive
, pp.64-68 http://dx.doi.org/10.14257/astl.2015.98.17 A Study on Laser Based Vision System for Inspection Height of Structural Adhesive Jun-Woo Son 1, Byoung-Ik Kim 2, Kyung-Jin Na 2, Myeong-Hwan Jeong
More informationPaper number ITS-EU-SP0127. Experimenting Bluetooth beacon infrastructure in urban transportation
11 th ITS European Congress, Glasgow, Scotland, 6-9 June 2016 Paper number ITS-EU-SP0127 Jukka Ahola (jukka.ahola@vtt.fi) 1*, Samuli Heinonen (samuli.heinonen@vtt.fi) 1 1. VTT Technical Research Centre
More informationElemental Image Generation Method with the Correction of Mismatch Error by Sub-pixel Sampling between Lens and Pixel in Integral Imaging
Journal of the Optical Society of Korea Vol. 16, No. 1, March 2012, pp. 29-35 DOI: http://dx.doi.org/10.3807/josk.2012.16.1.029 Elemental Image Generation Method with the Correction of Mismatch Error by
More informationUse of a Mobile BIM Application Integrated with Asset Tracking Technology over a Cloud
Use of a Mobile BIM Application Integrated with Asset Tracking Technology over a Cloud Park, J. 1 and Cho, Y.K. 2 * Abstract: Over the last decade, BIM and tracking have been explored by many researchers.
More information