著者 Tajima, Shigeto| Funabiki, Nobuo| Higashino, Teruo|
抄録 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.
キーワード wireless local-area network WLAN holding access-point partially overlapping channel assignment algorithm combinatorial optimisation problem
備考 This fulltext will be available in Apr 2019
発行日 2018-04-10
出版物タイトル International Journal of Space-Based and Situated Computing
8巻
1号
出版者 INDERSCIENCE ENTERPRISES
開始ページ 50
終了ページ 58
ISSN 2044-4893
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン author
DOI 10.1504/IJSSC.2018.091196
Web of Sience KeyUT 000437395700006
関連URL isVersionOf https://doi.org/10.1504/IJSSC.2018.091196
フルテキストURL ASTES_3_1_30.pdf
著者 Ei Ei Mon| Funabiki, Nobuo| Kusaka, Ryota| Khin Khin Zaw| Kao, Wen-Chung|
抄録 To advance Java programming educations, we have developed the Java Programming Learning Assistant System (JPLAS) that provides the code writing problem. This problem asks a student to write a source code to satisfy the specification of a given assignment, where the correctness is verified by running test code on JUnit. For a novice student, a code of implementing the standard input/output with the exception handling should be mastered at the early stage as the first step programming for human interfaces. However, for a teacher, it is not easy to write the test code for it. In this paper, we propose a test code generation method to generate the test code using the reference source code for the assignment. In the evaluation of this proposal, all the students completed the codes using the generated test codes for exception handling, although the use of exception handling functions was sometimes insufficient or incorrect.
キーワード Java programming JPLAS Test code Test case Automatic generation JUnit
発行日 2018-01-30
出版物タイトル Advances in Science, Technology and Engineering Systems Journal
3巻
1号
開始ページ 30
終了ページ 37
ISSN 24156698
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
DOI 10.25046/aj030105
関連URL isVersionOf http://dx.doi.org/10.25046/aj030105
著者 Khin Khin Zaw| Funabiki, Nobuo|
抄録 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.
キーワード Java programming learning assistant system JPLAS design-aware test code JUnit metric plugin breadth-first-search BFS
備考 This fulltext will be available in Dec 2018
発行日 2017-12-29
出版物タイトル International Journal of Space-Based and Situated Computing
7巻
3号
出版者 INDERSCIENCE ENTERPRISES
開始ページ 145
終了ページ 154
ISSN 2044-4893
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン author
DOI 10.1504/IJSSC.2017.089006
関連URL isVersionOf https://doi.org/10.1504/IJSSC.2017.089006
フルテキストURL IJCSE17_2_116_2017.pdf
著者 Ishihara, Nobuya| Funabiki, Nobuo| Kuribayashi, Minoru| Kao, Wen-Chung|
抄録 For advancements of Java programming educations, we have developed a Web-based Java Programming Learning System (JPLAS). JPLAS provides four problems with different levels, namely, element fill-inblank problem, value trace problem, statement fill-in-blank problem, and code writing problem, to cover students at different learning stages. Unfortunately, since JPLAS has been implemented by a number of students who studied in our group at different years, the code has become complex and redundant, which makes further extensions of JPLAS extremely hard. In this paper, we propose a software architecture for JPLAS to avoid redundancy. Based on the MVC model, our proposal uses Java for the model (M), HTML/CSS/JavaScript for the view (V), and JSP for the controller (C). Besides, adopting a design pattern, the marking functions of the four problems are implemented uniformly. For evaluations, after JPLAS is implemented with this architecture, the number of code files is compared with that of the previous implementation, and the number of additional files is examined for two new functions.
キーワード JPLAS Java programming education Web application MVC model Software architecture
発行日 2017-07-27
出版物タイトル International Journal of Computer & Software Engineering
2巻
1号
出版者 Graphy Publications
開始ページ 116
ISSN 2456-4451
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
DOI 10.15344/2456-4451/2017/116
関連URL isVersionOf https://doi.org/10.15344/2456-4451/2017/116
フルテキストURL IJNC_7_2_248.pdf
著者 Md. Selim Al Mamun| Funabiki, Nobuo| Kyaw Soe Lwin| Md. Ezharul Islam| Kao, Wen-Chung|
抄録 Recently, Wireless Local-Area Network (WLAN) has become prevailing as it provides flexible Internet access to users with low cost through installation of several types of access points (APs) in the network. Previously, we proposed the active AP configuration algorithm for the elastic WLAN system using heterogeneous APs, which dynamically optimizes the configuration by activating or deactivating APs based on traffic demands. However, this algorithm assumes that any active AP may use a different channel from the other ones to avoid interferences, although the number of non-interfered channels in IEEE 802.11 protocols is limited. In this paper, we propose the extension of the AP configuration algorithm to consider the channel assignment to the active APs under this limitation. Besides, AP associations of the hosts are modified to improve the network performance by averaging loads among channels. The effectiveness of our proposal is evaluated using the WIMNET simulator in two topologies. Finally, the elastic WLAN system including this proposal is implemented using Raspberry Pi for the AP. The feasibility and performance of the implementation are verified through experiments using the testbed.
キーワード Elastic WLAN system interference minimization channel assignment active access-point configuration algorithm testbed Raspberry Pi
発行日 2017-10-04
出版物タイトル International Journal of Networking and Computing
7巻
2号
出版者 IJNC Editorial Committee
開始ページ 248
終了ページ 270
ISSN 2185-2839
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
DOI 10.15803/ijnc.7.2_248
関連URL isVersionOf https://doi.org/10.15803/ijnc.7.2_248
フルテキストURL IJNC_7_2_187.pdf
著者 Kyaw Soe Lwin| Funabiki, Nobuo| Taniguchi, Chihiro| Khin Khin Zaw| Md. Selim Al Mamun| Kuribayashi, Minoru| Kao, Wen-Chung|
抄録 Recently, an IEEE 802.11n access point (AP) prevailed over the wireless local area network (WLAN) due to the high-speed data transmission using the multiple input multiple output (MIMO) technology. Unfortunately, the signal propagation from the 802.11n AP is not uniform in the circumferential and height directions because of the multiple antennas for MIMO. As a result, the data transmission speed between the AP and a host could be significantly affected by their relative setup conditions. In this paper, we propose a minimax approach for optimizing the 802.11n AP setup condition in terms of the angles and the height in an indoor environment using throughput measurements. First, we detect a bottleneck host that receives the weakest signal from the AP in the field using the throughput estimation model. To explore optimal values of parameters for this model, we adopt the versatile parameter optimization tool. Then, we optimize the AP setup by changing the angles and the height while measuring throughput. For evaluations, we verify the accuracy of the model using measurement results and confirm the throughput improvements for hosts in the field by our approach.
キーワード Wireless local area network access point setup MIMO throughput estimation model parameter optimization
発行日 2017-10-04
出版物タイトル International Journal of Networking and Computing
7巻
2号
出版者 IJNC Editorial Committee
開始ページ 187
終了ページ 207
ISSN 21852847
資料タイプ 学術雑誌論文
言語 English
OAI-PMH Set 岡山大学
論文のバージョン publisher
DOI 10.15803/ijnc.7.2_187
関連URL isVersionOf https://doi.org/10.15803/ijnc.7.2_187
著者 Funabiki, Nobuo| Singh, Amit| Mukherjee, Arindam| Sadowska, Malgorzata Marek|
発行日 2001-9
出版物タイトル Digital Systems
資料タイプ 学術雑誌論文
著者 Funabiki, Nobuo| Isogai, Megumi| Nakanishi, Toru| Higashino, Teruo|
発行日 2005-3
出版物タイトル Proceedings of the 19th International Conference on Advanced Information Networking and Applications
1巻
資料タイプ 会議発表論文
著者 Funabiki, Nobuo| Isogai, Megumi| Nakanishi, Toru| Higashino, Teruo|
発行日 2005-11
出版物タイトル Networks
1巻
資料タイプ 学術雑誌論文
著者 Funabiki, Nobuo| Sugano, Ayako| Higashino, Teruo|
発行日 2003-3
出版物タイトル Proceedings of the 17th International Conference on Advanced Information Networking and Applications
資料タイプ 会議発表論文
著者 Funabiki, Nobuo| Nomura, Yohei| Kawashima, Jun| Minamisawa, Yuichiro| Wada, Osami|
発行日 2006-3
出版物タイトル Electromagnetic Compatibility
資料タイプ 学術雑誌論文
著者 Funabiki, Nobuo| Nomura, Yohei| Kawashima, Jun| Minamisawa, Yuichiro| Wada, Osami|
発行日 2006-3
出版物タイトル Electromagnetic Compatibility
資料タイプ 学術雑誌論文
著者 Funabiki, Nobuo| Yokohira, Tokumi| Nakanishi, Toru| Tajima, Shigeto| Higashino, Teruo|
発行日 2001-10
出版物タイトル Systems
4巻
資料タイプ 学術雑誌論文
著者 船曳 信生| 磯貝 愛| 東野 輝夫| Oda Masashi|
発行日 2006-01
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
40巻
1号
資料タイプ 紀要論文