Earticle

Service is the core concept of future Internet that named Internet of Services. This concept refers to software components as well as processing capacity and any other resources that can be offered through the Internet. There is a need for a third party that make registering and searching services easy and feasible. Web Service Technology (WST) is one of those current solutions to the Internet of services that has attracted much attention. Registering and searching of the services are feasible by use of Service Directory. The current structure of WST that is mainly based on UDDI suffers from some structural shortcomings. From a structural point of view, service directory is implemented as a centralized node that is a performance bottleneck and single point of failure. In this paper, shortcomings of the current UDDI structure are analyzed through some quantitative experiments. Then, in order to address this shortcoming, a structure is presented by interlinking services using some sort of semantic relation that can be established between WST entities. Different aspects of structure and its performance enhancement are shown through experiments.

As many web contents, many of on-line wine quality rating information have been generated and released by individual expert and grouped experts. The purpose of this study is to explore the influence of subjective wine quality appraisal types on retail prices in Korean on-premise market. The authors analyzed the explanatory power of two types of appraisal, conducted by individual expert and expert group on 900 listed wines produced in 3 different countries and sold in 7 hotel restaurants and wine bars in Korea. Collective appraisals on Bordeaux and Bourgogne wine samples had stronger influence on retail price than individual appraisal. On other hand, individual appraisal on Champagne, Tuscans, Piedmont, and Californian wine samples had stronger influence than collective appraisals.

VANETs (Vehicular Ad hoc Networks) are upcoming wireless network environment for Intelligent Transportation Systems (ITS). Most VANET applications are built upon the data push communication model, where information is disseminated to a set of vehicles. The diversity of the VANET applications and their potential communication protocols needs a systematic literature survey. In this paper VANET characteristics and challenges are discussed. Application based various broadcasting data dissemination protocols are surveyed separately and their fundamental characteristics are revealed. In the end a tabular comparison of all the protocols is given.

This study develops a web-based discussion system applying Hill’s group cognitive map. We apply it to elementary school students and analyze the learning effects. Web-based discussion allows learners to actively participate in learning activities. It can facilitate multiple opportunities for learner-oriented interactions in web-based environments. Most web-based discussions occur through bulletin boards and data directories with the intention of creating basic communication exchanges among learners. Many instructional systems, however, are not built on rigorous, theoretically sound platforms. To avoid this trend and if we expect effective learning processes to consistently take place, the development of web-based discussion systems should be based on instructional models that are proven to be theoretically sound and effective in this environment. This decision could greatly influence the systems that are developed for online discussion. In an effort to contribute positively to the literature of web-based instruction, this study proposes the development of a web-based discussion system with Hill's Group Cognitive Map and presents the practical effects of the system such as the learners’ interest, capabilities for communication, and learning outcomes. The learning resources space was very useful for their learning. Seventy percent of the learners responded that learning through the web-based discussion system was effective. The students actively participated in team discussions on relevant themes in the instant messenger room. Those results could be obtained through the implementation of the system in an elementary school in South Korea.

In this paper, we propose a new ultra-wideband (UWB) antenna for UWB applications. The proposed antenna is designed to operate from 2 to 12 GHz. It consists of a T shape patch united with U shape patch with a partial ground plane to form an antenna. The proposed antenna is successfully simulated, designed, fabricated and measured. The measured results show that the proposed antenna with dimensions of 75 mm (Wsub) ×100 mm (Lsub) ×1:6 mm (H) has a large bandwidth over the frequency band from 2 GHz to 12 GHz with VSWR less than 2. The proposed antenna exhibits nearly omni directional radiation pattern, stable gain, and small group delay variation over the desired frequency bands. Details of the proposed antenna design and measured results are presented and discussed