INDERSCIENCE ENTERPRISES Acta Medica Okayama 2044-4893 8 1 2018 A holding access-point assignment algorithm for IEEE802.11 wireless local-area networks 50 58 EN Shigeto Tajima Nobuo Funabiki Teruo Higashino Nowadays, various types of access-points (APs) and hosts such as dedicated APs, laptop personal computers (PCs), and mobile terminals have been used in IEEE802.11 wireless local-area networks (WLANs). As a result, the optimal assignment of holding APs with different types into the network field, depending on the host type distribution, has become another important task to design high-performance WLANs. In this paper, we first define this holding access-point assignment problem as a combinatorial optimisation problem and propose its two-phase heuristic algorithm. Then, since plural partially overlapping channels are available in IEEE802.11 WLANs, we present the channel assignment extension to the APs such that the communication time of the APs is minimised, and the model to estimate the communication time increase by interferences. The effectiveness of our proposal is verified through simulations in six instances using the WIMNET simulator. No potential conflict of interest relevant to this article was reported.

INDERSCIENCE ENTERPRISES Acta Medica Okayama 2044-4893 7 3 2017 A design-aware test code approach for code writing problem in Java programming learning assistant system 145 154 EN Khin Khin Zaw Graduate School of Natural Science and Technology, Okayama University Nobuo Funabiki Graduate School of Natural Science and Technology, Okayama University To advance Java programming educations, we have developed the web-based Java programming learning assistant system (JPLAS) that provides the code writing problem. This problem asks a student to write a source code for a given assignment, where the correctness is verified by running the test code on JUnit. In this paper, we propose a design-aware test code approach for the code writing problem. The design-aware test code tests any important method in the model source code that has the advisable design for the assignment. Thus, by writing a code that can pass it, a student is expected to implement the code with the proper classes/methods in the model code. In evaluations of the proposal, all the students could complete highly qualitative codes for five graph algorithms using the design-aware test codes, where the code quality metrics were measured by metrics plugin for Eclipse. No potential conflict of interest relevant to this article was reported.