Jiann-Jone Chen

Design and Implementation of a Real-Time Object Location System Based on Passive RFID Tags

We investigate how to well utilize radio frequency identification techniques for real-time location systems (RTLS). A new control method, locate tracking tag through reader power control and candidate region intersection (LOCTREC), has been proposed to improve the RTLS estimation accuracy by eliminating trivial tag information from the estimation procedure. Multireaders were deployed and operated with multipower level to progressively refine the target tag region for accurate location estimation. To enhance the LOCTREC, visual tag interpolation algorithms were adopted to further refine the tag grid to enhance location estimation. Experiments showed that the estimation errors is 70% smaller than its counterpart of LANDMARC and SpotON which deploy regularly spaced reference tags to determine signal strength. For intuitive displaying the result, a video surveillance module was integrated with the RTLS to visually render the located objects, based on which context-aware services can be developed. One example is a smart wheelchair (SWC) with a friendly user-environment control interface that enables SWC users to interact with his living environment like a normal healthy person.

A hierarchical reliability-driven scheduling for cloud video transcoding

With the prevalence of personal computer devices and the Internet, a multimedia server has to perform video transcoding to serve users under heterogeneous network environments. In this paper, we propose a stability-driven hierarchical scheduling algorithm for the cloud-based video streaming system to speed up the video transcoding process for real-time service applications. The Multi-layer Division of the Max-MCT scheduling algorithm (MDMCT) has been developed to reduce the convoy effect. It helps to coordinate the system operations and dynamically adjust the number of slots so that the cloud cluster-s can finish the process more efficiently. Experimental result-s show that the proposed scheduling control method helps to maintain good system load balancing. The resources utilization of the entire cloud clusters can be maintained at about 98%, and the processing time can be reduced by about 13.4%.

Toward constructing a user-environment interface for a smart light-mobile wheelchair

Automatic and intelligent health care service becomes important with the growth of aged population. To achieve intelligent mobility for a smart wheelchair, we proposed to construct a user-environment interface that users can interact with the living environment like a normal healthy person. An integrated interactive platform, including touch control panel, together with several cameras, and wireless sensors, is embedded on a wheelchair to achieve friendly interaction. Interaction functions, such as appliance control, semi-automatic vision assistant function, and physiological information monitoring function etc. have been developed. The target of light mobility is achieved and the overall smart wheelchair system comprise: a mobile vehicle, information sensor modules, analysis control modules and an image capture unit which is set towards the headrest direction of the mobile vehicle to capture a users facial image data. The physiological information sensor module is used for sensing at least one physiological data of the user. The analysis control module outputs a seamless monitoring signal to a caregiver side in response to the image data or the at least one physiological data. These user-environment interaction functions are developed under the design target of human technology that the wheelchair user can interact with the environment like a normal person.

Human-centered wheelchairs: Bimanual gliding interface with heart rate monitoring

This paper presents a new wheelchair manipulation interface which is developed with bimanual gliding control interfaces. An important feature of the bimanual gliding control interface is performing intuitive manipulations when compared to conventional unilateral joystick interface. At the mean time, the bimanual gliding control interface also realizes the measurement of closed-line biopotential currents that flow in the thoracic volume conductor via a pair of surface electrodes placed on two gliding sensor modules. Therefore, the new designed bimanual gliding control interface does not only provide a feasible wheelchair manipulation interface, but also measure the users heart rate. Finally, a bimanual gliding (BG) wheelchair prototype is produced in this paper for performance evaluations.

A Dynamic and Complexity Aware cloud scheduling algorithm for video transcoding

Cloud video processing and streaming services has to be delivered under heterogeneous network and device environments. Scalable video coding and transcoding are required to serve heterogeneous users. As the task scheduling algorithm pre-configures a Hadoop MapReduce platform with the assumption of homogeneous node processing capability and task complexity, it cannot well accommodate the practical heterogeneous resources and tasks. In this research, we proposed a Dynamic Adjustment Slot and Complexity Aware Scheduler (DASCAS) algorithm to assign tasks under heterogeneous resources and tasks environments. Complexities of decomposed video segments are evaluated for setting task priority. The scheduling algorithm utilizes a speculative mechanism to detect potential late tasks to re-assign to other nodes for fast processing. It also monitors processing status of the distributed computer cluster and dynamically adjust the number of slots for load balance operations. Experiments show that the proposed method can reduce the transcoding time to 14%~24% smaller and improve the resource utilization rates to 2%~12% higher.

Toward enhancing the distributed video coder under a multiview video codec framework

Abstract. The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.

Design and implementation of a video transcoding system in cloud computing platforms

With the prevalence of personal computer devices and Internet, it has to provide scalable video coding to serve users under heterogeneous network environments. We proposed to develop a cloud-based video transcoding system, in which a hierarchical scheduling algorithm has been developed to speed up the process. The efficiency can be maintained at 98% and processing time can be reduced to 13% smaller.

Design and implementation of a DRM-enabled and stable P2P-IPTV system

With the advance of digital communication technologies and Internet prevalence, multimedia becomes one of the major media for information transmission. In this research, a stable and scalable IPTV system, which comprises media codecs, streaming, encryption/decryption, bandwidth estimation and NAT traversal units, has been developed to meet the application requirement of Internet multimedia. For streaming live videos, we proposed a Multi-Parameterized Adaptive Tree (MPAT) algorithm, which takes peer bandwidth capacity, peer online time, CPU utilization and transmission delay, to dynamically adjust the multicast tree for better P2P-IPTV services, i.e., low delay and few interruption times. Experiments show that the proposed P2P routing strategy can effectively reduce the overall system transmission delay, and improve the reliability of streaming and perception quality.

The freeform collimating lens designed for light transmission

This paper explores the design of a collimating lens based on freeform method. With this freeform structure, the light can be propagated as nearly parallel light which allow the light be transmitted to a large distance without substantial loss.

The human-environment interface design with a vision assistance module or a smart wheelchair

Automatic and intelligent health care service becomes important with the growth of aged population. To achieve intelligent mobility for a smart wheelchair, we proposed to construct a friend user-environment interface that users can interact with the living environment like a normal healthy person. An integrated interactive platform, including touch control panel, together with several cameras, and wireless sensors, is embedded on a wheelchair to achieve human interaction. Interaction functions, such as appliance control, semi-automatic vision assistant function, and physiological information monitoring function etc. have been developed to achieve the target. The goal of light mobility can be reached and the overall smart wheelchair system comprises: a mobile vehicle, information sensor modules, analysis control modules and an image capture unit which is set towards the headrest direction of the mobile vehicle to capture human facial image data. The physiological sensor module is used for sensing user physiological data. The analysis control module seamlessly transmits monitoring signals to a caregiver side in response to the image data or physiological data. These user-environment interaction functions are developed under the design target of human technology that the wheelchair user can interact with the environment like a normal person.