APMEC: An Automated Provisioning Framework for Multi-access Edge Computing

Novel use cases and verticals such as connected cars and human-robot cooperation in the areas of 5G and Tactile Internet can significantly benefit from the flexibility and reduced latency provided by Network Function Virtualization (NFV) and Multi-Access Edge Computing (MEC). Existing frameworks managing and orchestrating MEC and NFV are either tightly coupled or completely separated. The former design is inflexible and increases the complexity of one framework. Whereas, the latter leads to inefficient use of computation resources because information are not shared. We introduce APMEC, a dedicated framework for MEC while enabling the collaboration with the management and orchestration (MANO) frameworks for NFV. The new design allows to reuse allocated network services, thus maximizing resource utilization. Measurement results have shown that APMEC can allocate up to 60% more number of network services. Being developed on top of OpenStack, APMEC is an open source project, available for collaboration and facilitating further research activities

S-PRAC: Fast Partial Packet Recovery with Network Coding in Very Noisy Wireless Channels

Well-known error detection and correction solutions in wireless communications are slow or incur high transmission overhead. Recently, notable solutions like PRAC and DAPRAC, implementing partial packet recovery with network coding, could address these problems. However, they perform slowly when there are many errors. We propose S-PRAC, a fast scheme for partial packet recovery, particularly designed for very noisy wireless channels. S-PRAC improves on DAPRAC. It divides each packet into segments consisting of a fixed number of small RLNC encoded symbols and then attaches a CRC code to each segment and one to each coded packet. Extensive simulations show that S-PRAC can detect and correct errors quickly. It also outperforms DAPRAC significantly when the number of errors is high

Comparative Assessment of Climate Engineering Scenarios in the Presence of Parametric Uncertainty

Climate engineering (CE) measures are increasingly discussed when dealing with the adverse impacts of climate change. While much research has focused on individual methods, few studies attempt to compare and rank the effectiveness of these measures. Furthermore, model uncertainties are seldom acknowledged and lesser still, estimated when CE scenarios are assessed. In this work, we quantify the variance in outcomes due to poorly constrained model parameters under several idealized CE scenarios. The four scenarios considered are (1) warming under the high emission scenario Representative Concentration Pathway 8.5 without CE applied and the same emission scenario with (2) afforestation,(3) solar radiation management, and (4) artificial ocean alkalinization. By considering the parametric uncertainty in model outputs, we demonstrate the problems with comparing these scenarios using a single parameter setting. Using statistical emulation, we estimate the probability distributions of several model outcomes. Based on such distributions, we suggest an approach to ranking the effectiveness of the scenarios considered according to their probability of avoiding climate thresholds

Evolutionary Clustering of Apprentices' Self- Regulated Learning Behavior in Learning Journals

Learning journals are increasingly used in vocational education to foster self-regulated learning and reflective learning practices. However, for many apprentices, documenting working experiences is a difficult task. In this article, we profile apprentices' learning behavior in an online learning journal. Based on a pedagogical framework, we propose a novel multistep clustering pipeline that integrates different learning dimensions into a combined profile. Specifically, the profiles are described in terms of effort, consistency, regularity, help-seeking behavior, and quality of the written entries. Our results on two populations of chef apprentices (183 apprentices) interacting with an online learning journal (over 121K entries) show that our pipeline captures changes in learning patterns over time and yields interpretable profiles that can be related to academic performance. The obtained profiles can be used as a basis for personalized interventions, with the ultimate goal of improving the apprentices' learning experience

Fast IMU-based Dual Estimation of Human Motion and Kinematic Parameters via Progressive In-Network Computing

Many applications involve humans in the loop, where continuous and accurate human motion monitoring provides valuable information for safe and intuitive human-machine interaction. Portable devices such as inertial measurement units (IMUs) are applicable to monitor human motions, while in practice often limited computational power is available locally. The human motion in task space coordinates requires not only the human joint motion but also the nonlinear coordinate transformation depending on the parameters such as human limb length. In most applications, measuring these kinematics parameters for each individual requires undesirably high effort. Therefore, it is desirable to estimate both, the human motion and kinematic parameters from IMUs. In this work, we propose a novel computational framework for dual estimation in real-time exploiting in-network computational resources. We adopt the concept of field Kalman filtering, where the dual estimation problem is decomposed into a fast state estimation process and a computationally expensive parameter estimation process. In order to further accelerate the convergence, the parameter estimation is progressively computed on multiple networked computational nodes. The superiority of our proposed method is demonstrated by a simulation of a human arm, where the estimation accuracy is shown to converge faster than with conventional approaches

Assessment of Aspergillus flavus Infection and Aflatoxin Contamination in Groundnut in Southern Vietnam

Groundnut is an important food and cash crop in Vietnam with a high export potential. Limited studies of foods in the country have indicated that aflatoxin contamination is a problem in groundnut and maize. Vietnam considers the aflatoxin problem in groundnut to be of great importance, especially in view of Vietnam's expanding trade in this commodity, and the increasing use of groundnut cake as animal feed, Systematic surveys were conducted to assess Aspergillus flevus infection and aflatoxin contamination in groundnuts from farmers' fields and marketsloil mills in the major groundnut-growing areas of southern Vietnam. Results indicated that preharvest aflatoxin contamination is not likely to be a serious problem in adequately irrigated groundnuts. However, groundnuts grown under residual moisture or limited irrigation can be contaminated under conducive environmental conditions prevailing in the winter-spring season as evidenced by moderate to high aflatoxin levels found in some samples. Soilborne diseases such as stemlpod rot and bacterial wilt prevalent in many parts of southern Vietnam are likely to encourage A. flavus invasion of podlseed in the field. It is emphasized that the aflatoxin problem should be viewed holistically as contamination can be pre- and postharvest with many factors influencing, e,g., the crop rotation, soil moisture, soilborne pests and diseases, crop produce drying and storage conditions. A brochure on "Aflatoxin contamination problems in groundnuts and groundnut products" was prepared (in English and Vietnamese) and distributed to many farmers, traders, and extension and research workers to enhance awareness of the aflatoxin problem and management option

Occurrence of White Grubs in Groundnut Crop in Uplands of South Vietnam: A New Report

Groundnut (Arachis hypogaea) is an important crop in South Vietnam covering more than 125,000 ha under different cropping systems. Crop surveys, and the onfarm research organized in Trang Bang, Cuchi, Duc Hoa and Go Dau during the past (until 2000), brought out the importance of the foliage feeding insect pests (Spodoptera, Helicoverpa) as economically important in farmers’ fields (Ranga Rao 1995). Field visits during the last week of May 2004 and interactions with the farmers in Tra Vinh province, villages around Cau Ngang town revealed the occurrence and importance of white grubs in this region. This soil-inhabiting pest is a menace in this area, which is in the heart of Mekong delta mostly covered by irrigated rice (Oryza sativa) cultivation with multiple cropping system

TSN-FlexTest: Flexible TSN Measurement Testbed (Extended Version)

Robust, reliable, and deterministic networks are essential for a variety of applications. In order to provide guaranteed communication network services, Time-Sensitive Networking (TSN) unites a set of standards for time-synchronization, flow control, enhanced reliability, and management. We design the TSN-FlexTest testbed with generic commodity hardware and open-source software components to enable flexible TSN measurements. We have conducted extensive measurements to validate the TSN-FlexTest testbed and to examine TSN characteristics. The measurements provide insights into the effects of TSN configurations, such as increasing the number of synchronization messages for the Precision Time Protocol, indicating that a measurement accuracy of 15 ns can be achieved. The TSN measurements included extensive evaluations of the Time-aware Shaper (TAS) for sets of Tactile Internet (TI) packet traffic streams. The measurements elucidate the effects of different scheduling and shaping approaches, while revealing the need for pervasive network control that synchronizes the sending nodes with the network switches. We present the first measurements of distributed TAS with synchronized senders on a commodity hardware testbed, demonstrating the same Quality-of-Service as with dedicated wires for high-priority TI streams despite a 200% over-saturation cross traffic load. The testbed is provided as an open-source project to facilitate future TSN research.Comment: 30 pages, 18 figures, 6 tables, IEEE TNSM, in print, 2024. Shorter version in print in IEEE Trans. on Network and Service Management (see related DOI below