• Title/Summary/Keyword: location-based-Service

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A Study on Indoor Position-Tracking System Using RSSI Characteristics of Beacon (비콘의 RSSI 특성을 이용한 실내 위치 추적 시스템에 관한 연구)

  • Kim, Ji-seong;Kim, Yong-kab;Hoang, Geun-chang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.5
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    • pp.85-90
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    • 2017
  • Indoor location-based services have been developed based on the Internet of Things technologies which measure and analyze users who are moving in their daily lives. These various indoor positioning technologies require separate hardware and have several disadvantages, such as a communication protocol which becomes complicated. Based on the fact that a reduction in signal strength occurs according to the distance due to the physical characteristics of the transmitted signal, RSSI technology that uses the received signal strength of the wireless signal used in this paper measures the strength of the transmitted signal and the intensity of the attenuated received signal and then calculates the distance between a transmitter and a receiver, which requires no separate costs and makes to implement simple measurements. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance.It was confirmed that the RSSI values through the average filtering and the RSSI values measured by setting the coefficient value of the feedback filtering to 0.5 were ranged from -61 dBm to - 52.5 dBm, which shows irregular and high values decrease slightly as much as about -2 dBm to -6 dBm as compared to general measurements.

Recommendation of Best Empirical Route Based on Classification of Large Trajectory Data (대용량 경로데이터 분류에 기반한 경험적 최선 경로 추천)

  • Lee, Kye Hyung;Jo, Yung Hoon;Lee, Tea Ho;Park, Heemin
    • KIISE Transactions on Computing Practices
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    • v.21 no.2
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    • pp.101-108
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    • 2015
  • This paper presents the implementation of a system that recommends empirical best routes based on classification of large trajectory data. As many location-based services are used, we expect the amount of location and trajectory data to become big data. Then, we believe we can extract the best empirical routes from the large trajectory repositories. Large trajectory data is clustered into similar route groups using Hadoop MapReduce framework. Clustered route groups are stored and managed by a DBMS, and thus it supports rapid response to the end-users' request. We aim to find the best routes based on collected real data, not the ideal shortest path on maps. We have implemented 1) an Android application that collects trajectories from users, 2) Apache Hadoop MapReduce program that can cluster large trajectory data, 3) a service application to query start-destination from a web server and to display the recommended routes on mobile phones. We validated our approach using real data we collected for five days and have compared the results with commercial navigation systems. Experimental results show that the empirical best route is better than routes recommended by commercial navigation systems.

A Store Recommendation Procedure in Ubiquitous Market for User Privacy (U-마켓에서의 사용자 정보보호를 위한 매장 추천방법)

  • Kim, Jae-Kyeong;Chae, Kyung-Hee;Gu, Ja-Chul
    • Asia pacific journal of information systems
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    • v.18 no.3
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    • pp.123-145
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    • 2008
  • Recently, as the information communication technology develops, the discussion regarding the ubiquitous environment is occurring in diverse perspectives. Ubiquitous environment is an environment that could transfer data through networks regardless of the physical space, virtual space, time or location. In order to realize the ubiquitous environment, the Pervasive Sensing technology that enables the recognition of users' data without the border between physical and virtual space is required. In addition, the latest and diversified technologies such as Context-Awareness technology are necessary to construct the context around the user by sharing the data accessed through the Pervasive Sensing technology and linkage technology that is to prevent information loss through the wired, wireless networking and database. Especially, Pervasive Sensing technology is taken as an essential technology that enables user oriented services by recognizing the needs of the users even before the users inquire. There are lots of characteristics of ubiquitous environment through the technologies mentioned above such as ubiquity, abundance of data, mutuality, high information density, individualization and customization. Among them, information density directs the accessible amount and quality of the information and it is stored in bulk with ensured quality through Pervasive Sensing technology. Using this, in the companies, the personalized contents(or information) providing became possible for a target customer. Most of all, there are an increasing number of researches with respect to recommender systems that provide what customers need even when the customers do not explicitly ask something for their needs. Recommender systems are well renowned for its affirmative effect that enlarges the selling opportunities and reduces the searching cost of customers since it finds and provides information according to the customers' traits and preference in advance, in a commerce environment. Recommender systems have proved its usability through several methodologies and experiments conducted upon many different fields from the mid-1990s. Most of the researches related with the recommender systems until now take the products or information of internet or mobile context as its object, but there is not enough research concerned with recommending adequate store to customers in a ubiquitous environment. It is possible to track customers' behaviors in a ubiquitous environment, the same way it is implemented in an online market space even when customers are purchasing in an offline marketplace. Unlike existing internet space, in ubiquitous environment, the interest toward the stores is increasing that provides information according to the traffic line of the customers. In other words, the same product can be purchased in several different stores and the preferred store can be different from the customers by personal preference such as traffic line between stores, location, atmosphere, quality, and price. Krulwich(1997) has developed Lifestyle Finder which recommends a product and a store by using the demographical information and purchasing information generated in the internet commerce. Also, Fano(1998) has created a Shopper's Eye which is an information proving system. The information regarding the closest store from the customers' present location is shown when the customer has sent a to-buy list, Sadeh(2003) developed MyCampus that recommends appropriate information and a store in accordance with the schedule saved in a customers' mobile. Moreover, Keegan and O'Hare(2004) came up with EasiShop that provides the suitable tore information including price, after service, and accessibility after analyzing the to-buy list and the current location of customers. However, Krulwich(1997) does not indicate the characteristics of physical space based on the online commerce context and Keegan and O'Hare(2004) only provides information about store related to a product, while Fano(1998) does not fully consider the relationship between the preference toward the stores and the store itself. The most recent research by Sedah(2003), experimented on campus by suggesting recommender systems that reflect situation and preference information besides the characteristics of the physical space. Yet, there is a potential problem since the researches are based on location and preference information of customers which is connected to the invasion of privacy. The primary beginning point of controversy is an invasion of privacy and individual information in a ubiquitous environment according to researches conducted by Al-Muhtadi(2002), Beresford and Stajano(2003), and Ren(2006). Additionally, individuals want to be left anonymous to protect their own personal information, mentioned in Srivastava(2000). Therefore, in this paper, we suggest a methodology to recommend stores in U-market on the basis of ubiquitous environment not using personal information in order to protect individual information and privacy. The main idea behind our suggested methodology is based on Feature Matrices model (FM model, Shahabi and Banaei-Kashani, 2003) that uses clusters of customers' similar transaction data, which is similar to the Collaborative Filtering. However unlike Collaborative Filtering, this methodology overcomes the problems of personal information and privacy since it is not aware of the customer, exactly who they are, The methodology is compared with single trait model(vector model) such as visitor logs, while looking at the actual improvements of the recommendation when the context information is used. It is not easy to find real U-market data, so we experimented with factual data from a real department store with context information. The recommendation procedure of U-market proposed in this paper is divided into four major phases. First phase is collecting and preprocessing data for analysis of shopping patterns of customers. The traits of shopping patterns are expressed as feature matrices of N dimension. On second phase, the similar shopping patterns are grouped into clusters and the representative pattern of each cluster is derived. The distance between shopping patterns is calculated by Projected Pure Euclidean Distance (Shahabi and Banaei-Kashani, 2003). Third phase finds a representative pattern that is similar to a target customer, and at the same time, the shopping information of the customer is traced and saved dynamically. Fourth, the next store is recommended based on the physical distance between stores of representative patterns and the present location of target customer. In this research, we have evaluated the accuracy of recommendation method based on a factual data derived from a department store. There are technological difficulties of tracking on a real-time basis so we extracted purchasing related information and we added on context information on each transaction. As a result, recommendation based on FM model that applies purchasing and context information is more stable and accurate compared to that of vector model. Additionally, we could find more precise recommendation result as more shopping information is accumulated. Realistically, because of the limitation of ubiquitous environment realization, we were not able to reflect on all different kinds of context but more explicit analysis is expected to be attainable in the future after practical system is embodied.

A Study on Level of Service of Sidewalk and Satisfaction of Pedestrian (보도의 서비스수준과 보행자 만족도에 대한 연구)

  • Kwon, Wantaeg;Kim, Sangyoup;Choi, Jaisung;Kim, Taeho;Jang, Youngsoo;Kim, Jinsub
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.3
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    • pp.129-145
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    • 2016
  • This paper analyzed and compared the service level and satisfaction of the sidewalks in collector roads from 6 different location, which has a lot of volume of pedestrians. For the study, it performed an investigation of road geometry, flow, research about satisfaction of walking and video recording. Based on this data, this study computed the service level of the sidewalks and pedestrian satisfaction. This study made a sense of correlation between service level and satisfaction. Also it focused on factors influencing on the effectiveness of satisfaction. This study also analyzed the change of walking behavior chracteristics according to the change of the level of satisfaction. This study adopted Multi-Modal Level of Service(MMLOS) method, because it could consider more factors. This study reached the conclusion that MMLOS method cannot completely reflect the level of pedestrian satisfaction. We have to consider more factors than in the current system for use in the development of sidewalk design. The result of this study is expected to reflect the pedestrian satisfaction in future sidewalks design.

The Impact of Offshoring on Korean Firms' Productivity (오프쇼어링이 한국 기업의 생산성에 주는 영향)

  • Park, Moon-Soo;Kim, Hwa-Nyeon;Lee, Kyung-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.4784-4790
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    • 2013
  • As with fast growing globalization, Korean firms have increased their offshoring activities and more empirical research are needed to analyze the effect of offshoring on Korean firms' productivity. This study used "Survey of Business Activities", a firm-level panel data set surveyed by the Statistics Korea between 2006 and 2008, and estimated pooled OLS and Panel fixed effect model to examine the impact of offshoring on a firm's labor productivity. Unlike the previous studies on offshoring, we included in the analyses the firms in the service industry in addition to those in the manufacturing industry, and presented the comparative results. The results from pooled OLS model show that 1% increase in the share of offshoring output will lead to 0.03% increase in labor productivity. However, the results from Panel model show that the effects of offshoring on productivity is positive but statistically insignificant. Analyzing the manufacturing and the service sector separately, the main results based on Panel model can be summarized as follows: Offshoring has significant positive effects on firms' productivity in the manufacturing industry. Contrastingly, the impact of offshoring on firms' productivity in the service industry is estimated to be negative but statistically insignificant. Other than the share of offshoring output, most factors except headquarter location have positive effects on firms' productivity in both manufacturing and service industry.

An Ambient Service Model for Providing Web's Stores Information on Map Interface Hierarchically through User-Context-Based Search (사용자 상황기반 검색을 통해 웹상의 상점정보를 지도상에 계층적으로 제공하는 엠비언트 서비스 모델)

  • Seo, Kyung-Seok;Lee, Ryong;Jang, Yong-Hee;Kwon, Yang-Jin
    • Spatial Information Research
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    • v.18 no.2
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    • pp.57-65
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    • 2010
  • Users often visit many stores while comparing the products for purchasing products or products related to it. Given a service providing location information of these stores, users can make their purchase efficiently because of reducing the time and effort they spent for wandering around and obtaining new purchase opportunities by knowing a kind of relevant stores near there. In this paper, for the purpose of providing relevant stores information efficiently, we suggest an Ambient Service Model that consists of three layers: "structured(purchase-related) information space", "real space", and "ambient information space". In the model, stores information collected from the web is grouped and structured automatically by relationships in terms of purchase. And users search relevant stores information by using an Ambient Query that is created by their context in real space. Finally, users obtain relevant stores information that is in the form of hierarchy structure on map interface. Then, users can search other kinds of relevant stores information additionally by using hierarchy structure. Consequently, It is possible to develope a service that users can obtain relevant stores information intuitively without complex search processes through the model. Also, we expect that the model can be used for developing services that provide objects information related to various objects besides stores.

A Development of Punctuality Index for Bus Operation Using Time-space Diagram (시공도를 이용한 버스운행 정시성 지표개발)

  • Yang, Ji-Young;Kim, Young-Chan;Kim, Seung-Il
    • Journal of Korean Society of Transportation
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    • v.23 no.8 s.86
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    • pp.129-138
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    • 2005
  • Since Successive introduction of BMS(Bus Management System) into the local governments has been able to collect each bus data on the road and valuate the bus operation by the quantitative index not qualitative index. we need a study on punctuality index for evaluation of service level for bus operation using bus location information. We propose punctuality index for bus operation using time-space diagram and valuate the index by application to real bus data.

An LED Positioning Method Using Image Sensor of a Smart Device (LED 조명과 스마트 디바이스의 이미지 센서를 이용한 실내 측위 기법)

  • Kim, Jae-Hoon;Kim, Byoung-Sup;Jeon, Hyun-Min;Kang, Suk-Yon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.390-396
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    • 2015
  • The drastic growth of mobile communication and spreading of smart phone make the significant attention on Location Based Service. The one of most important things for vitalizations of LBS is the accurate estimating position for mobile object. Focusing on an image sensor deployed in smart phone, we develop a LED based positioning estimation framework. The developed approaches can strengthen the advantages of independent indoor applicability of LED. The estimation of LED based positioning is effectively applied to any indoor environment. We put a focus especially on the algorithmic framework. of image processing of smart phone. From LED lighting, we can obtain a typical signal image which contains the unique positioning information. Furthermore test-bed based on smart phone platform is practically developed and all data have been harvested from the actual measurement of test indoor area. This can approve the practical usefulness of proposed framework.

Intelligent Vocabulary Recommendation Agent for Educational Mobile Augmented Reality Games (교육용 모바일 증강현실 게임을 위한 지능형 어휘 추천 에이전트)

  • Kim, Jin-Il
    • Journal of Convergence for Information Technology
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    • v.9 no.2
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    • pp.108-114
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    • 2019
  • In this paper, we propose an intelligent vocabulary recommendation agent that automatically provides vocabulary corresponding to game-based learners' needs and requirements in the mobile education augmented reality game environment. The proposed agent reflects the characteristics of mobile technology and augmented reality technology as much as possible. In addition, this agent includes a vocabulary reasoning module, a single game vocabulary recommendation module, a battle game vocabulary recommendation module, a learning vocabulary list Module, and a thesaurus module. As a result, game-based learners' are generally satisfied. The precision of context vocabulary reasoning and thesaurus is 4.01 and 4.11, respectively, which shows that vocabulary related to situation of game-based learner is extracted. However, In the case of satisfaction, battle game vocabulary(3.86) is relatively low compared to single game vocabulary(3.94) because it recommends vocabulary that can be used jointly among recommendation vocabulary of individual learners.

A Random ID-based RFID Mutual authentication protocol for detecting Impersonation Attack against a back-end server and a reader (서버와 리더의 위장공격 탐지가 가능한 랜덤 ID기반 RFID 상호 인증 프로토콜)

  • Yeo, Don-Gu;Lee, Sang-Rae;Jang, Jae-Hoon;Youm, Heung-Youl
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.20 no.4
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    • pp.89-108
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    • 2010
  • Recently many mutual authentication protocol for light-weight hash-based for RFID have been proposed. Most of them have assumed that communications between a backend server and reader are secure, and not considered threats for backend server and RFID reader impersonation. In the real world, however, attacks against database or reader are more effective rather than attacks against RFID tag, at least from attacker's perspective. In this paper, we assume that all communications are not secure to attackers except the physical attack, and considering realistic threats for designing a mutual authentication protocol based on hash function. And It supports a mutual authentication and can protect against the replay attack, impersonation attack, location tracking attack, and denial of service attack in the related work. We besides provide a secure and efficient RFID mutual authentication protocol which resists impersonation attacks on all of the entities and alow a backend server to search tag-related information efficiently. We conclude with analyzing the safety and efficiency among latest works.