Foreword of Special Issue on "Nomadic Services and Applications"

Nomadic Service has emerged rapidly as an exciting new paradigm that offers a challenging model of cyber-physical services and poses fascinating problems regarding distributed resource management, ranging from information sharing to cooperative computing. This special issue is intended to foster state-of-the-art research in the area of nomadic services and related applications, cloud computing technologies and services, including the topics of collaboration environment, implementation and execution of real-world architectures, and novel applications associated with this new paradigm. The published papers are expected to present high quality results for tackling problems arising from the ever-growing cloud computing technologies. The issue will serve as a landmark source for education, information, and reference to professors, researchers and graduate students interested in updating their knowledge about or active in cloud computing technologies and services. Nine papers are included in this special issue.  In the first paper entitled “Broadcasting Data Items with Time Constraints Based on On-Demand Multichannel in Ubiquitous Environments”, Dr. Ding-Jung Chiang and Timothy K. Shih proposes mobile services with time constraints in ubiquitous computing environments based on on-demand multichannel broadcasting. This study provides on-line scheduling strategies for mobile data with timing constraint on multichannel broadcasting environments based on on-demand mode. The goal of this study ensures the most requests meeting their deadlines, which differs from previously proposed scheduling algorithms that aim to minimize the mean access time. The experimental results show the proposed algorithm, called on-demand broadcast program with time constraint (BPTC), outperforms miss rate for data timely delivery to mobile clients.  In order to illustrate a real-time hand gesture recognition system by using shape context matching and cost matrix, the second paper entitled “Real-time Hand Gesture Recognition by Shape Context Based Matching and Cost Matrix” by Prof. Lawrence Y. Deng, Jason C. Hung, Huan-Chao Keh, Lin Kun-Yi, Yi-Jen Liu, and Nan-Ching Huang tried to develop a perceptual interface for human-computer-interaction based on real-time hand gesture recognition. User could interact with computer program by performing body gesture instead of physical contact. The image of hand gesture was captured from CCD. The hand gesture image was transformed into proper instruction according to the shape information respectively. Prof. Jiung-yao Huang, Huan-Chao Keh, Wai Shu-Shen, Ji-jen Wu, and Chung-Hsien Tsai purposed to enable users in a physical place to receive ubiquitous services from the environment while they communicate with each other unwittingly. In the third paper entitled “Research of Place-based 3D Augmented Community-Taking The 3D Virtual Campus as an Example”, with the help of the augmented reality technique, on-the-spot member can visually sense the remote users by their representing avatars. To achieve this goal, the ambient communication environment is required to support message flow among the remote users and people on site. The context issues and context-awareness approaches of PDA community are fully discussed in the paper. Finally, the infrastructure of this PDA community is also presented along with preliminary result of the prototyping environment. “Interactive E-diagnosis: An Efficient Scheme for Medical Diagnosis Supporting System” written by Rong-Chi Chang aims to design a prototype medical diagnostic support system, in which DICOM-based image analysis algorithms are utilized to develop an image browser and graphical user interface (GUI), allowing medical personnel to read X-ray, CT scan, MRI or other medical imaging files via a simple browser interface. The system also combines Internet functionality to provide remote medical diagnosis and patient data query features, all of which are conducive for doctors or medical personnel in different regions to cooperate and get hold of real-time test images and information of the patient. Follow-up studies can seek to incorporate a more convenient patient information entry and update interface into the system for automatic image analysis and information retrieval, where the data can be stored in the patient's personal information for up-to-date medical records.   In “A Web-based E-learning Platform for Physical Education”, Prof. Chun-Hong Huang, Su-Li Chin, Li-Hua Hsin, Jason C. Hung, Yi-Pei Yu developed a Web-based E-learning Platform for physical education. The Platform provides sports related courseware which includes physical motions, exercise rules and first-aid treatment. The courseware is represented using digital multimedia materials which include video, 2D animation and 3D virtual reality. The design concept of this project is based on ADDIE model with the five basic phases of analysis, design, development, implementation, and evaluation. Via the usage of this Web-based E-learning platform, user can learn the relative knowledge about sports at anytime and in everyplace. Authors hope to let players perform efficient self learning for sports skills, indirectly foster mutual help, cooperation, nice norms of law-abiding via the learning of exercise rules, and become skilled at accurate recreation knowledge and first-aid expertise. Prof. Shih-Yang Yang, Ching-Ming Chao, Po-Zung Chen and Chu-Hao Sun proposed the ICspan algorithm to continue mining sequential patterns through an incremental approach and to acquire a more accurate mining result. In addition, due to the algorithm constraint in closed sequential patterns mining, the generation and records for sequential patterns will be reduced, leading to a decrease of memory usage and to an effective increase of execution efficiency. In the sixth paper entitled “Incremental Mining of Closed Sequential Patterns in Multiple Data Streams”, the experiment results also support that ICspan algorithm will effectively reduce the sequential pattern records and consequently reducing the memory usage, while maintaining a sound mining efficiency under continuous data entries. “Developing a Web-based and Competition-based Quiz Game Environment to Improve Student Motivation” written by Prof. Kuan-Cheng Lin, Ting-Kuan Wu and Yu-Bin Wang. In this study, authors develop a web-based and competition-based multi-player quiz game environment (WCMQGE) by incorporating DGBL into the web-based e-learning system. During the process of the game, the WCMQGE system can help players (students) review what they learned from school and use their knowledge to compete with their peers. In “Using Active RFID to Realize Ubi-media System”, Prof. Jason C. Hung purposed a human computer interface which is based on Active Radio frequency identification (Active RFID) technique to let human communicate with computer by analyzing the signal from tags. For retrieving those signals from tags, how to decreasing the noises created by surrounding environment and detecting useful information from variant signals are the most important. Author adopted a train procedure as pre-processing to categorize all of signals into two categories: noise and real data. After the real data is retrieved, we use “Music Director” and “DJ Scratch” as applications to let user play with computer.  In the ninth paper entitled “On the Design of A Contribution-based, Flexible Locality-Aware P2P Streaming Network”, Yu-Wei Chan proposed the design of a two layered hybrid tree-push/mesh-pull overlay network with considering the problems of locality-aware of peers and incentive schemes. Prof. Chan proposed the schemes and algorithms to overcome the mismatch problem between the overlay network and the physical network, reduce the transmission latency, and provide a fully cooperative and reliable P2P streaming environment.