An auction framework for DaaS in cloud computing and its evaluation

Data-as-a-service (DaaS) is the next emerging technology in cloud computing research. Small clouds operating as a group may exploit the DaaS efficiently to perform the substantial amount of work. In this paper, an auction framework is studied and evaluated when the small clouds are strategic in nature. We present the system model and formal definition of the problem and its experimental evaluation. Several auction DaaS-based mechanisms are proposed and their correctness and computational complexity is analysed. To the best of our knowledge, this is the first and realistic attempt to study the DaaS in a strategic setting. We have evaluated the proposed approach under various simulation scenarios to judge on its usefulness and efficiencyPeer ReviewedPostprint (author's final draft

SIGNAGE YANG INFORMATIF DAN INTERAKTIF PADA THE HERITAGE PALACE KOTA SURAKARTA JAWA TENGAH

The Heritage Palace is located in Surakarta City of Central Java which formerly was the sugar factory that is currently used as a tourist attraction. However, this place has the problem of lacking its informative and interactive signage, less by the branding of the tourist spots, and less proper in material selection. The data collection used were the literature study, observation, interviews and questionnaires, using comparison matrix as data analysis method. The concept of the design takes the modern and old heritage concept using a font that matches the clear language and adds pictogram. The purpose of this design is to provide informative and interactive information using signage ang interactive media that is useful to help visitors get information when they visit the tourist sit

Object-based Information Flow Control in Peer-to-peer Publish/Subscribe Systems

Distributed systems are getting so scalable like IoT (Internet of Things) and P2P (Peer-to-Peer) systems that millions of devices are connected and support various types of applications. Here, distributed systems are required to be secure in addition to increasing the performance, reliability, and availability and reducing the energy consumption. In distributed systems, information in objects flows to other objects by transactions reading and writing data in the objects. Here, some information of an object may illegally flow to a subject which is not allowed to get the information of the object. Especially, a leakage of sensitive information is to be prevented from occurring. In order to keep information systems secure, illegal information flow among objects has to be prevented. Types of synchronization protocols are so far discussed based on read and write access rights in the RBAC (Role-Based Access Control) model to prevent illegal information flow.In this thesis, we newly propose a P2PPSO (P2P type of topic-based PS (Publish/Subscribe) with Object concept) model and discuss the models and protocols for information flow control. A P2PPSO model is composed of peer processes (peers) which communicate with one another by publishing and subscribing event messages. Each peer can both publish and receive event messages with no centralized coordinator compared with traditional centralized PS models. Each event message published by a source peer carries information to a target peer. The contents carried by an event message are considered to be composed of objects. An object is a unit of data resource. Objects are characterized by topics, and each event message is also characterized by topics named publication topics.In order to make a P2PPSO system secure, we first newly propose a TBAC (Topic-Based Access Control) model. Here, an access right is a pair ⟨t, op⟩ of a topic t and a publish or subscribe operation op. A peer is allowed to publish an event message with publication topics and subscribe interesting topics only if the publication and subscription access rights are granted to the peer, respectively. Suppose an event message e_j published by a peer p_j carries an object on some topics into a target peer p_i. Here, information in the peer p_j illegally flows to the peer p_i if the target peer p_i is not allowed to subscribe the topics. An illegal object is an object whose topics a target peer is not allowed to subscribe. Even if an event message is received by a target peer by checking topics, objects carried by the event message may be illegal at the target peer. Hence, first, we propose a TOBS (Topics-of-Objects-Based Synchronization) protocol to prevent target peers from being delivered illegal objects in the P2PPSO system. Here, even if an event message is received by a target peer, illegal objects in the event message are not delivered to the target peer.In the TOBS protocol, every event message is assumed to be causally delivered to every common target peer in the underlying network. Suppose an event message e_2 is delivered to a target peer p_i before another event message e_1 while the event message e_1 causally precedes the event message e_2 (e_1 →_c e_2). Here, the event message e_2 is premature at the peer p_i. Hence, secondly, we propose a TOBSCO (TOBS with Causally Ordering delivery) protocol where the function to causally deliver every pair of event messages is added to the TOBS protocol. Here, we assume the underlying network supports reliable communication among every pair of peers, i.e. no event message loss, no duplicate message, and the sending order delivery of messages. Every pair of event messages received by using topics are causally delivered to every common target peer by using the vector of sequence numbers.In the TOBS and TOBSCO protocols, objects delivered to target peers are held as replicas of the objects by the target peers. If a peer updates data of an object, the peer distributes event messages, i.e. update event messages, to update every replica of the object obtained by other peers. If a peer updates an object without changing topics, the object is referred to as altered. Here, an update event message for the altered object is meaningless since peers check only topics to exchange event messages. Hence, thirdly, we propose an ETOBSCO (Efficient TOBSCO) protocol where update event messages of objects are published only if topics of the objects are updated to reduce the network overhead.In the evaluation, first, we show how many numbers of event messages and objects are prevented from being delivered to target peers in the TOBS protocol. Next, we show every pair of event messages are causally delivered but it takes longer to deliver event messages in the TOBSCO protocol than the TOBS protocol. Finally, we show the fewer number of event messages are delivered while it takes longer to update replicas of altered objects in the ETOBSCO protocol than the TOBSCO protocol.博士(工学)法政大学 (Hosei University

Taxonomy of digital signage message execution and media placement considerations

Digital signage is a commercial promising field in marketing. Yet, it is a little researched topic, with an incomplete understanding of the factors to consider when planning digital signage message executions or media placements. There is no systematic, cohesive foundation to describe and study the features of this promising contemporary digital platform. This paper addresses an academic-practitioner divide by developing an orderly categorisation of digital signage message execution and media placement considerations and research. It offers a well-ordered conceptualisation of digital signage types and guidelines for selecting content types, formats, display quality and technical interactive designs. The resulting taxonomy is of relevance to retailers and marketers aiming to optimise utilitarian or hedonic value. Some guidance for prospect research is provided, particularly assessing the varies opportunities offered by different digital signage content types; designing experiments compare the effectiveness of digital display quality, sizes, placement and designs at different locations. The possible obstacles of interactive digital signage also deserve future research

サーバクラスタでの低消費電力化のための移行モデルの研究

博士(工学)法政大学 (Hosei University