Ya-Fen Chang and Jen-Ho Yang

Cloud computing becomes a hot research topic recently.Before the concept of cloud computing was introduced,similar concepts or computing models have been proposed such as distributed computing and grid computing. Cloud computing is composed of a front end, a back end, cloud computing services, and cloud computing technologies.Though several institutes and companies, such as NIST,Google, Microsoft, IBM, and Wikipedia, define cloud computing with different definitions, could computing must provide the following four properties. (1) Users can access services via the Internet. (2) Resources can be dynamically managed and arranged. (3) There exists a distributed virtual architecture. (4) Because of requested services and demands, possible fees may be charged.

The objective of this special issue is to present research and development activities that are currently taking place in the various aspects of cloud computing by bringing together the most recent results concerning the relevant topics. We hope this special issue will encourage computer scientists to get interested and involved in this promising and active research area. After a very careful review of many highly qualified submissions, the editorial committee accepted 18 papers included in this special issue.

The included papers are divided into 4 categories according to the involved research topics concerning cloud computing: (1) cloud computing technologies, (2) cloud computing services, (3) cloud computing applications, and(4) cloud computing security.

Proper cloud computing technologies make cloud servers or systems work efficiently and resources utilized well. Prof. Charles Hung-Pin Wen and Prof. Li-Chun Wang with their research team at National Chiao Tung University propose MapReduce modified cuckoo search (MRMCS),an efficient MCS implementation on an MapReduce architecture (Hadoop), to search optimality from huge amounts of data samples for applications. Prof. Liang-Teh Lee and Prof. Chia-Ying Tseng with their research team at Tatung University propose a method, called MBFDP(modified best fit decreasing packing), to decrease power consuming and enhance resource utilization of cloud computing servers. Prof. Ping-Liang Chen, Prof. Yu-Cheng Lin, and Prof. Shin-Jia Chen at Kainan University propose a genetic algorithm based approach to allocate the power spectrum dynamically. Prof. Chin-Fu Kuo at National University of Kaohsiung and Prof. Yung-Feng Lu at National Taichung University of Science and Technology with their their research team propose a configurable secure gateway architecture, which allows the system administrators to dynamically configure the security mechanisms upon deployment or during the run-time.

Cloud computing services can be divided into three models: (1) software as a service (SaaS), (2) plateform as a service (PaaS), and (3) infrastructure as a service (IaaS).According to deployment mechanisms, cloud computing services can be divided into three categories: (1) public cloud, (2) private cloud, and (3) hybrid cloud. No matter which kind of cloud computing service model is applied, it always can be built by the above three deployment mechanisms. There still exist many urgent issues in cloud computing services now. Prof. Wen-Lung Shiau and his research team at Ming Chuan University propose a unified framework of the cloud computing service model, which is comprehensive and appropriate for the current complexities of businesses. Prof. Liang-Teh Lee and his research team at Tatung University propose a high efficiency scheduling scheme for supporting cloud computing. Prof. Sze-Yao Li,Prof. Chun-Ming Chang, and Prof. Yuan-Yu Tsai with their research team at Asia University propose a database distribution management system, DBDM, which partitions or replicates the data according to the transaction behaviors of the application system. Prof. Chi-Lun Liu at Kainan University proposes a novel access control method for personal cloud service business to make service providers potentially provide cloud service providers with a convenient method of controlling user access according to changeable business and marketing strategies.

Various cloud computing applications make peoples’daily life convenient. Prof. Chung-Yang Chen and his research team at National Central University use the e-tag technology on the campus parking management system based on the cloud-based construction. Prof. Yu-Cheng Lin at Kainan University proposes a campus equipment ubiquitous-management system based on a genetic algorithm approach in cloud server. Prof. Young-Long Chen and his research team at National Taichung University of Science and Technology design a house lease management system in cloud computing. To check if the applications suit users’ requirements, further analyses are essential. Prof. Hui-Hsin Huang at Aletheia University proposes a dynamic model of customer interpurchase time as geometric distribution. Prof. Anthony Y. H. Liao at Asia University and his research team develop a cloud-based supply chain integration service platform of manufacturing industry. In the platform, the members of whole supply chain integration services cloud can work together, and rapidly deploy and dynamically allocate resources, and the computer hardware and software resources of upstream and downstream can be appropriately shared. Prof. Anthony Y.H. Liao at Asia University and his research team propose a cloud-based e-learning assessment and remedial tutoring system. They also demonstrate that the learning on Chinese idioms through the proposed system is superior to the traditional way of reading. Prof. Iuon-Chang Lin and his research team at National Chung Hsing University find the key attributes influencing the user trust towards applications on the mobile application store.

How to protect information security in cloud computing environment is an important issue to ensure essential security requirements and make resources or services accessible to legal users. Prof. Ping-Liang Chen, Prof.Jen-Ho Yang, and Prof. Ching-I Lin at Kainan University propose an ID-based user authentication scheme to provide anonymity and security for the user who accesses different cloud servers. Prof. Ya-Fen Chang and her research team at National Taichung University of Science and Technology propose a biometric identity-based signcryption scheme,which combines signature and encryption. In their proposed scheme, biometric information is used to construct the private key to ensure uniqueness, and a user’s identity is the corresponding public key to make the message transfer non-interactive. Prof. Min-Shiang Hwang at National Chung Hsing University and Prof. Lin-Yu Tseng at Providence University propose a reversible data hiding scheme for medical images in cloud computing environments with their research team. Their proposed scheme employs chaotic Hénon map as an encryption technique to achieve an acceptable level of confidentiality in cloud computing environments.

On behalf of the editorial committee, we express our sincere thanks to all authors and reviewers for their great contribution to this special issue. Also, we thank the editorial committee members for their excellent assistance.Finally, we are grateful to the editorial staff for their help.Without all of the contributions of these hard-working,dedicated people, it would have been impossible to produce this special issue.