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In Second or Foreign Language (SFL) education, a number of studies in applied linguistics have addressed a common issue of how teachers can provide effective feedback to correct learner's erroneous utterances during a classroom hour. Oral Corrective Feedback (OCF) is generally time-consuming and labor-intensive work for teachers. The use of ASR (Automatic Speech Recognition) in SFL education has drawn attention from both teachers and learners to increase the learning effect and efficiency. We designed and integrated Quantitative OCF using Google Cloud Speech-to-Text as a part of the oral assessment using an LMS (Learning Management System) for Japanese SFL courses. The level of learners is a starter's level without any prerequisite knowledge of Japanese language. Preliminary experiments using a total of 214 audio datasets by non-native speakers exhibited that 37.4% of the datasets were recognized properly as Japanese sentences. However, as the remainder of the datasets contains erroneous utterances, characteristics of intonation, or noise, ASR successfully detected word-based errors with high accuracy (82.4%) but low precision (28.1%). Oral assessment employing ASR is highly promising as a complementary system for teachers on partially automating the assessment of audio data from learners with evidence and priority orders as well as significantly reducing teachers' scoring workload and time spent on the most problematic part of the students' speech. While our implementation still requires teachers to double-check, such overhead is small and affordable.

A type of Bitcoin node called "Full Node" has to hold the entire of historical transaction data called "Blockchain" to verify that new transactions are correct or not. To operate nodes as Full Nodes, the required storage size will be too large for resource-constrained devices. In this paper, to mitigate storage size, we propose a storage load balancing scheme by distributed storage based on Distributed Hash Table (DHT). By our scheme, nodes in a DHT cluster can behave like Full Nodes without holding the entire of the blockchain.

As a mode of Japanese language education, a spoken Japanese course without Japanese characters (Hiragana, Katakana, Kanji) for reading/writing is a promising option to attract more Japanese learners with easier beginning to make. However, existing language teaching methods, even using ICT, suffer from issues of scalability and learning effect when deployed in a large-scale spoken language class. This paper proposes to effectively use Learning Management System to improve the scalability, efficiency, and effectiveness of Japanese language and culture education. The course using LMS is practiced and evaluated in an actual large-scale Japanese language class with more than 100 students in an overseas university. The proposed LMS 1) enables individual monitoring and feedback mechanism of each student, 2) visualizes the learning progress and achievement, and 3) provides a comprehensive User Interface to manage online homework and exams. To the best knowledge of the authors, the use of LMS in a large-scale spoken Japanese class has not been well studied. The evaluation results exhibited the load reduction of course management and the various benefit of LMS, which natively digitizes the contents management and can increase the students' engagement in the class.

With cloud service becoming more popular, low-latency communication is required between servers in a data center. Low-latency node-to-node or application-to-application notification can be achieved in a NUMA [1] (Non-Uniform Memory Access) system, but requires dedicated, special-purpose network infrastructure. However, IP networks are commonly used in data centers. Using a custom FPGA-based NIC, we create NUMA-like behavior using hardware-generated IP packets which can be transmitted over commodity Ethernet switches and IP routers. We demonstrate ping-pong acknowledgments between two PCs equipped with our IP-NUMA boards. Our IP-NUMA implementation exhibits latency as much as ten times lower than software using Berkeley sockets over a consumer-grade Ethernet switch. iSCSI initiator-target communications and transaction-based distributed software systems will benefit from the reduced latency.

We propose the Floating Ground Architecture (FGA) for network mobility and ad hoc network convergence. Various factors, including excessive dependence on intelligence in the fixed network, result in the Internet having a de facto logical boundary one hop from the fixed network. To reduce these dependencies, FGA introduces a new logical layer, called Floating Ground, between the fixed network infrastructure and the mobile network, aiming to bridge these different types of network systems. Thanks to the effect of this buffer layer, the architecture: 1) optimizes routes in a deeply nested mobile router arrangement, 2) simplifies mobility event handling under frequent movement of the nodes, and 3) transparently introduces additional functionality with no additional intelligence on the infrastructure side. Through evaluation of our proposed architecture using an actual software implementation running via Direct Code Execution simulation, optimized routes are confirmed with three possible mobility scenarios, demonstrating the handoff duration is dramatically reduced in the short-distance movement scenario, which happens in 78.4%, at maximum, of the handoff events under actual taxi cabs movement in real world. Qualitative analysis of FGA shows it minimizes modification of the network components and existing standardized protocols, and is therefore more suitable for self-organized, distributed network extension than competitive approaches.

Masayoshi Mizutani Keio University, Graduate School of Media and Governance 5322 Endo Fujisawa-shi Kanagawa, Japan mizutani@sfc.wide.ad.jp Keiji Takeda Keio University, Faculty of Environment and Information Studies 5322 Endo Fujisawa-shi Kanagawa, Japan keiji@sfc.keio.ac.jp Jun Murai Keio University, Faculty of Environment and Information Studies 5322 Endo Fujisawa-shi Kanagawa, Japan jun@wide.ad.jp

International audience; Despite years of research in ad hoc routing protocols, only a few have been investigated in the context of MANEMO (MANET for NEMO), which provides a hierarchical structured network and global connectivity. Motivated by the deployment of post-disaster MANEMOs composed of mobile routers and stations, we evaluate two candidate routing protocols through analytical models, simulation, and field experiments. The first protocol is the widely adopted Optimized Link State Routing protocol (OLSR) and the second is the combination of the Tree Discovery Protocol (TDP) with Network In Node Advertisement (NINA). To the best of our knowledge, this is the first time that these two protocols are compared in both theoretical and practical terms. We focus on the control overhead generated when nodes perform a handover. Our results confirm the correctness and operational robustness of both protocols. More interestingly, although in the general case OLSR leads to better results, TDP/NINA outperforms OLSR in the case of sparse networks, which corresponds to the operation point of our target scenario.

Many developing countries are not gaining benefits from the Internet as the network infrastructure has not yet been built due to the economic or administrative restrictions of these regions. Asian Internet Interconnection Initiatives (AI3) has been developing a research consortium of 29 partner institutions in 13 countries utilizing an Internet infrastructure over a satellite links. The project aims to develop partnerships and human networks to foster researchers within the regions to carry out research on the satellite Internet and to develop their regions. We have successfully conducted productive research and also developed a distance-learning environment as a result of more than a decade of experiments. This paper aims to share the operational know-how and results of research from AI3's activities to construct a network and applications that would support developing regions.

A multihomed node has several paths with its correspondent, maintained by several multihoming protocols. The decision to route a packet over a specific path relies on filter rules, which result from the comparison between the path's characteristics and the user policy. Multihoming protocols or their implementations provide various user interfaces to configure the filter rules. However, there is currently no method to describe user policy in terms of cost, bandwidth, delay and other network characteristics, and to compare this policy with the path characteristics. We thus propose in this paper a new framework for policy management for flow distribution, which offers a user interface to define policies and generates filter rules for each multihoming protocol. We first sort out the requirements for users in the multihomed environment. By reviewing some of the most important multihoming protocols and implementations, we show that they do not match all those requirements. We then propose a new policy management framework that fits those very requirements.