Location based services are very useful to human beings. The vehicle navigation service that is used by almost all drivers in the world is an example location based service. As the man made constructions are getting bigger and bigger, indoor location based services are demanded. Matter of fact, researches for indoor location based service started in the early 1990s and developing techniques wit...

Dual-frequency Global Positioning System (GPS) Real-time Kinematics (RTK) has been proven in the past few years to be a reliable and efficient technique to obtain high accuracy positioning. However, there are still challenges for GPS single-frequency RTK, such as low reliability and ambiguity resolution (AR) success rate, especially in kinematic environments. Recently, multi-Global Navigation S...

This paper present our color constancy investigation in the hybridization of Wireless LAN and Camera positioning in the mobile phone. Five typical color constancy schemes are analyzed in different location environment. The results can be used to combine with RF signals from Wireless LAN positioning by using model fitting approach in order to establish absolute positioning output. There is no co...

In recent years, Radio Frequency Identification (RFID) is followed with interest by many researches, especially for the purpose of indoor positioning as the innate properties of RFID are profitable for achieving it. A lot of algorithms or schemes are proposed to be used in the RFID-based positioning system, but most of them are lack of environmental consideration and it induces inaccuracy of ap...

The use of GPS for indoor positioning poses difficult challenges due to very weak signal levels, and accuracies are typically of the order of tens to hundreds of metres at best. To overcome this severe limitation Locata Corporation has invented a new positioning technology called Locata, for precision positioning both indoors and outside. Part of the “Locata technology” consists of a time-synch...

Inertial sensors are widely used in various applications, such as human motion monitoring and pedestrian positioning. However, inertial sensors cannot accurately define the process of human movement, a limitation that causes data drift in the process of human body positioning, thus seriously affecting positioning accuracy and stability. The traditional pedestrian dead-reckoning algorithm, which...

introduction: the use of panoramic radiography has shown a remarkable expansion over the past 20 years. accurate positioning and preparation of patients is needed to avoid image distortion. the aim of this study was to evaluate the common errors on panoramic radiographs taken in the radiology department of rasht dental school. materials and methods: the study sample included 390 digital panoram...

The problem of identification and mitigation of the Non Line Of Sight (NLOS) effects in Ultra Wideband (UWB) indoor localization is a very challenging ongoing topic in the research community. There are two groups of methods applied in UWB indoor localization: indirect two-step localization methods and direct one-step localization methods [1]. Two-step localization methods are widely investigate...

Though GPS is the most popular positioning system at present it does not perform well in indoor environments and metropolitan city areas. Wi-Fi positioning has received much attention due to its advantages with respect to indoor positioning and the wide spread of the Wi-Fi access points (APs). Its performance in an outdoor environment is also of interest as a Wi-Fi based positioning system can ...

Every computer needs a timer mechanism to keep track of current time and also for various accounting purposes such as calculating the time spent by a process in CPU utilization, disk I/O, and so on, so that the corresponding user can be charged properly. In a distributed system, an application may have processes that concurrently run on multiple nodes of the system. For correct results, several...