A Smart Checkpointing Scheme for Improving the Reliability of Clustering Routing Protocols

In wireless sensor networks, system architectures and applications are designed to consider both resource constraints and scalability, because such networks are composed of numerous sensor nodes with various sensors and actuators, small memories, low-power microprocessors, radio modules, and batteries. Clustering routing protocols based on data aggregation schemes aimed at minimizing packet numbers have been proposed to meet these requirements. In clustering routing protocols, the cluster head plays an important role. The cluster head collects data from its member nodes and aggregates the collected data. To improve reliability and reduce recovery latency, we propose a checkpointing scheme for the cluster head. In the proposed scheme, backup nodes monitor and checkpoint the current state of the cluster head periodically. We also derive the checkpointing interval that maximizes reliability while using the same amount of energy consumed by clustering routing protocols that operate without checkpointing. Experimental comparisons with existing non-checkpointing schemes show that our scheme reduces both energy consumption and recovery latency

ヒガシアジア ノ カゾク キギョウ ト ジギョウ ショウケイ : ソノ キョウツウセイ ト タヨウセイ : コメント ト オウトウ 2

コメントと応答・質疑応答会期・会場: 2023年12月23日:同志社大学今出川校地至誠館S32教室(3階)通訳: 洪性奉application/pdfarticl

Towards priority-awareness in autonomous intelligent systems

In Autonomous and Intelligent systems (AIS), the decision-making process can be divided into two parts: (i) the priorities of the requirements are determined at design-time; (ii) design selection follows where alternatives are compared, and the preferred alternatives are chosen autonomously by the AIS. Runtime design selection is a trade-off analysis between non-functional requirements (NFRs) that uses optimisation methods, including decision-analysis and utility theory. The aim is to select the design option yielding the highest expected utility. A problem with these techniques is that they use a uni-scalar cumulative utility value to represent a combined priority for all the NFRs. However, this uni-scalar value doesn't give information about the varying impacts of actions under uncertain environmental contexts on the satisfaction priorities of individual NFRs. In this paper, we present a novel use of Multi-Reward Partially Observable Markov Decision Process (MR-POMDP) to support reasoning of separate NFR priorities. We discuss the use of rewards in MR-POMDPs as a way to support AIS with (a) priority-aware decision-making; and (b) maintain service-level agreement, by autonomously tuning NFRs' priorities to new contexts and based on data gathered at runtime. We evaluate our approach by applying it to a substantial Network case

Towards an architecture integrating complex event processing and temporal graphs for service monitoring

Software is becoming more complex as it needs to deal with an increasing number of aspects in volatile environments. This complexity may cause behaviors that violate the imposed constraints. A goal of runtime service monitoring is to determine whether the service behaves as intended to potentially allow the correction of the behavior. It may be set up in advance the infrastructure to allow the detections of suspicious situations. However, there may also be unexpected situations to look for as they only become evident during data stream monitoring at runtime produced by te system. The access to historic data may be key to detect relevant situations in the monitoring infrastructure. Available technologies used for monitoring offer different trade-offs, e.g. in cost and flexibility to store historic information. For instance, Temporal Graphs (TGs) can store the long-term history of an evolving system for future querying, at the expense of disk space and processing time. In contrast, Complex Event Processing (CEP) can quickly react to incoming situations efficiently, as long as the appropriate event patterns have been set up in advance. This paper presents an architecture that integrates CEP and TGs for service monitoring through the data stream produced at runtime by a system. The pros and cons of the proposed architecture for extracting and treating the monitored data are analyzed. The approach is applied on the monitoring of Quality of Service (QoS) of a data-management network case study. It is demonstrated how the architecture provides rapid detection of issues, as well as the ability to access to historical data about the state of the system to allow for a comprehensive monitoring solution

ヒガシアジア ノ カゾク キギョウ ト ジギョウ ショウケイ : ソノ キョウツウセイ ト タヨウセイ : シツギ オウトウ

コメントと応答・質疑応答会期・会場: 2023年12月23日:同志社大学今出川校地至誠館S32教室(3階)司会: 藤本昌代application/pdfarticl

호르몬 미세 환경을 반영한 미세유체 소자 내 유방암-혈관 모델 개발

학위논문(석사) - 한국과학기술원 : 기계공학과, 2019.2,[vi, 45 p. :]Breast cancer remains the leading cause of deaths among women in the world. It has a complex biological mechanisms and it is challenging to experimentally access the human body in vivo. In response to these issues, researchers have developed vascularized breast cancer models in PDMS microfluidic platforms as a new tool to better understand the complex mechanisms behind human breast cancer. However, there remain some challenges in recapitulating all aspects of breast cancer using current microfluidic breast cancer models. The majority of vascularized breast cancer models that have been developed as of 2018 do not consider the effects of hormone and hydrophobic anti-cancer drugs. This results from small hydrophobic molecules such as hormone and some drugs that are absorbed or adsorbed to the PDMS, which comprises hydrophobic polymer networks. In response, we develop a 3D perfusable vasculature model combined with breast cancer cells by co-culturing HUVECs and breast cancer cell lines (MCF-7 or MDA-MB-231) in an absorption-free cyclic olefin copolymer (COC) microfluidic device to analyze the effects of the major female hormone estradiol and the anti-cancer drug tamoxifen, which are both small hydrophobic molecules. First, we confirmed that estradiol stimulates the cell proliferation of ER-positive MCF-7 cells contrary to ER-negative MDA-MB-231 cells. Second, it was observed that estradiol prevented cell apoptosis of MCF-7 seeded with fibrin gel induced by treatment of tamoxifen. Finally, from our vasculature model combined with breast cancer cells in a COC microfluidic device, we presented that the treatment of estradiol with tamoxifen enhanced the cell viability of vascular networks as well as MCF-7 cells compared to tamoxifen treatment alone. These results demonstrate that it is essential to consider the effects of the hormone microenvironment and hydrophobic anti-cancer drugs in a microfluidic platform for the studies of vascularized breast cancer models.한국과학기술원 :기계공학과