Many indoor localization techniques that rely on RF signals from wireless Access Points have been proposed in the last decade. In recent years, research on crowdsourced (also known as “Organic”) Wi-Fi fingerprint positioning systems has been attracting much attention. This participatory approach introduces new challenges that no previously proposed techniques have taken into account. This paper proposes “FreeLoc”, an efficient localization method addressing three major technical issues posed in crowdsourcing based systems. Our novel solution facilitates 1) extracting accurate fingerprint values from short RSS measurement times 2) calibration-free positioning across different devices and 3) maintaining a single fingerprint for each location in a radio map, irrespective of any number of uploaded data sets for a given location. Through experiments using four different smartphones, we evaluate our new indoor positioning method. The experimental results confirm that the proposed scheme provides consistent localization accuracy in an environment where the device heterogeneity and the multiple surveyor problems exist.

Sickle Cell Disease (SCD) is a common chronic inherited disorder of red blood cells requiring careful pain management, particularly for youth. Clinicians and researchers have developed efficient pain management methods, from the traditional paper and pencil method to the computer-based electronic diaries (e-Diary). With the recent proliferation of smartphones and the advancement in mobile Internet connectivity, a new healthcare technology has become available. This paper presents a mobile e-Diary platform for youth with SCD utilizing the Internet capability of modern mobile phones. Unlike previous e-Diary systems ours is completely based on the Web technology, thus it has the advantage of platform-independence. The proposed system is designed to help children write everyday diary and provide appropriate pain management by healthcare providers. The usability and reliability of the system was evaluated with youths with SCD in conjunction with the UCLA Nursing School during 6-month study period. Our pilot study confirmed that the proposed web-based mobile e-Diary system could be used as a template for other pediatric chronic illnesses interventions in youth with other chronic illnesses.

Providing vehicles' position is essential in VANETs. Currently, GPS positioning is widely used, but the accuracy is not adequate for emerging safety applications. In order to provide accurate positioning, this paper proposes RF-GPS, a RFID-assisted localization system that reliably supports lane-level position accuracy. It improves accuracy of the GPS system by employing a DGPS-like concept. It also allows vehicles without GPS to compute their position by contacting GPS equipped neighbors. We evaluate the performance of the proposed localization system via simulation.