A plasma display device includes: a dielectric layer on which a plurality of through-holes of a dielectric layer is disposed in a matrix shape; upper and lower electrode layers formed at both upper and lower surfaces of the dielectric layer; upper and lower substrates disposed on the outer surface of the upper and lower electrode layers; and a third electrode layer having a plurality of third electrodes which are formed between the upper substrate and the upper electrode layer, or the lower substrate and the lower electrode layer, and are insulated from the upper and lower electrode layers. Accordingly, a plasma display device can be realized which has stability and efficiency of a micro discharge. In addition, each pixel can concurrently carry out a sustain discharge by applying an alternating voltage to upper and lower electrodes forming sustain electrodes.

Plasma Display Panel

Indoor localization is essential for healthcare, security, augmented reality gaming, and many other location-based services. There is currently a wealth of relevant literature on indoor localization. This article focuses on recent advances in indoor localization methods that use spatial context to improve the location estimation. Spatial context in the form of maps and spatial models have been used to improve the localization by constraining location estimates in the navigable parts of indoor environments. Landmarks such as doors and corners, which are also one form of spatial context, have proved useful in assisting indoor localization by correcting the localization error. This survey gives a comprehensive review of state-of-the-art indoor localization methods and localization improvement methods using maps, spatial models, and landmarks.

Indoor Localization Improved by Spatial Context—A Survey

In this letter we propose a novel ranging algorithm for the asynchronous location positioning system. The main idea of the proposed algorithm is to reply with multiple acknowledgement packets to a single ranging request. The ranging algorithm reduces the number of packets used in ranging process and improves the ranging accuracy at the same time.

Double-sided two-way ranging algorithm to reduce ranging time

For wireless positioning system, a study on two-way ranging algorithms has been progressed to improve the accuracy of position estimates. In this paper, we propose an asynchronous Double Two-Way Ranging (D-TWR) algorithm, executing an overlapped Two-Way Ranging (TWR) effectively. In this way, the D-TWR algorithm can reduce the number of the required packets in the ranging algorithm as compared with that of the Symmetric Double Sided Two-Way Ranging (SDS-TWR) algorithm. Moreover, D-TWR can achieve more robust Time-of-Arrival (TOA) estimation than SDS-TWR by reducing the TOA estimation errors caused by clock crystal drift between two nodes.

A new Double Two-Way Ranging algorithm for ranging system

Ultra-wideband localization systems are widely known to perform with high accuracy using time-of-flight (TOF) algorithms, which are demanding in terms of tag-side power consumption. Systems optimized for power efficient tags are prone to be implemented using time-difference of arrival (TDOA) algorithms. However, due to dilution of precision and the additional required synchronization, TDOA systems suffer from limited accuracy outside the area covered by the anchors. This work presents a new technique, combining TDOA and TOF measurements in a power efficient way. Experimental results are compared with pure TOF and TDOA measurements. The results of the new combined technique show similar accuracy and a reduction of 75 % tag-side power consumption compared to the TOF method.

Experimental results of a combined TDOA/TOF technique for UWB based localization systems

In a real-time locating system which does not require time synchronization among nodes, it takes a very long time to complete a ranging process for a single location estimation. Long ranging time makes mobile nodes consume a significant amount of battery power and limits the number of mobile nodes that a single fixed node can handle during a specific time interval. Therefore, it is crucial to shorten the ranging time in asynchronous locating systems without degradation in ranging or locating accuracy. In this paper, we propose an asynchronous two-way ranging scheme which reduces ranging time by replying with multiple packets to a single ranging request. The algorithm reduces ranging time by 17% or more, compared to that of existing methods.

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A ranging scheme for asynchronous location positioning systems

In this paper we evaluate the performance of the SDS-TWR-MA (Symmetric Double-Sided Two-Way Ranging with Multiple Acknowledgement) algorithm. The main idea of the ranging algorithm, which proposed in our previous work [5], is to reply with multiple acknowledgement packets to a single ranging request. The algorithm reduces the number of packets used for ranging process especially when we iterate it several times to yield a stabler ranging result. According to our analysis, the proposed ranging algorithm can reduce the ranging time by 30% or more, while keeping the locating accuracy high. Furthermore, the proposed algorithm allows us to use a coarse oscillator for precise location positioning by diminishing the influence of clock offset or clock drift.

Performance analysis of the SDS-TWR-MA algorithm

A plasma display device including: a front substrate and a rear substrate assembled to face each other; partition walls equidistantly disposed between the front and rear substrates to define a plurality of discharge cells; phosphorous layers respectively formed on inner surfaces of discharge cells; groups of stripe-shaped electrodes formed on the front and rear substrates to be orthogonal with respect to each other; and a reflective plate installed at the back surface of the rear substrate.

Plasma display panel having reflective plate with light shielding walls

A gateway comprising a first port connected to a network and a second port connected to a target node and being employed for a data stream between the network and applications of the target node, the gateway further comprising: a storage unit to store an IP address of the target node; an MAC address converter to set an MAC address of the target node as an MAC address of the first port; a controller to set an IP address of the second port based on an IP address of the target node, and to read the MAC address of the target node through the second port and set the IP address of the target node as an IP address of the first port; and a router to set a transmission route and transmit data to the IP address of the target node without a local loop back process, in response to the IP address of the target node and the IP address of the first port being the same.

Hakyong Kim

Papers

Double-sided two-way ranging algorithm to reduce ranging time

A ranging scheme for asynchronous location positioning systems

Performance analysis of the SDS-TWR-MA algorithm

Plasma display panel having reflective plate with light shielding walls

Gateway and control method thereof