バングラデシュにおけるヒ素汚染低減政策の有効性 : 井戸水と尿中のヒ素濃度との関連性から

博士(医学)大阪市立大

A technique to avoid Blockchain Denial of Service (BDoS) and Selfish Mining Attack

Blockchain denial of service (BDoS) and selfish mining are the two most crucial attacks on blockchain technology. A classical DoS attack targets the computer network to limit, restrict, or stop accessing the system of authorized users which is ineffective against renowned cryptocurrencies like Bitcoin, Ethereum, etc. Unlike the conventional DoS, the BDoS affects the system's mechanism design to manipulate the incentive structure to discourage honest miners to participate in the mining process. In contrast, in a selfish mining attack, the adversary miner keeps its discovered block private to fork the chain intentionally that aiming to increase the incentive of the adversary miner. This paper proposed a technique to successfully avoid BDoS and selfish mining attacks. The existing infrastructure of blockchain technology doesn't need to be changed a lot to incorporate the proposed solution.Comment: 6 pages, 10 figure

A Secure Land Record Management System using Blockchain Technology

A land record (LR) contains very sensitive information related to land e.g. owner, buyer, etc. Currently, almost all over the world, the LR is maintained by different governmental offices and most of them maintain the LR with paper-based approach. Some of the works focus to digitalize the existing land record management system (LRMS) but with some security concerns. A blockchain-based LRMS can be effective enough to solve the existing issues. This paper proposes a blockchain-based LRMS that (i) digitalizes the existing paper-based system, (ii) ensures LR privacy using an asymmetric cryptosystem, (iii) preserves LR integrity, (iv) facilitates a platform for trading land through an advertising agency, and (v) accelerates the process of changing ownership that saves time significantly. Besides, this paper also proposes a new way of character to integer mapping named C2I table that reduces around 33% overhead of text to integer conversion compared to ASCII table. The experimental results, analyses, and comparisons indicate the effectiveness of the proposed LRMS over the state-of-the-art systems.Comment: 6 pages, 5 tables, 10 figures, ICCIT 202

酸化還元活性な金属錯体を用いた機能化によるCO2電解還元能の向上

Tohoku University山下正廣課

Numerical analysis of pile groups in multi-layered soil subjected to negative skin friction

Several linear elastic and nonlinear slip models are reported in the literature for predicting negative skin friction on piles and pile groups in consolidating soils. They often produce significantly different results. Moreover, these models are either complex and unfeasible in practice or not capable of taking soil stratification into account, especially in pile groups. These make it difficult for practicing engineers to select appropriate method for predicting negative skin friction. In this thesis, after critically reviewing the existing methods of analysis and examining the inherent mechanisms involved in pile-soil interaction process, a numerical method is proposed for analysis of the negative skin friction on piles and pile groups. The soil response along the depth of the pile is represented by a number of hyperbolic load transfer relationships, each of which relates the load mobilized to the pile at a particular depth and the corresponding relative soil displacement. The method uses conventional laboratory soil test data as input and incorporates nonlinear load transfer mechanism into an iterative finite element framework. A computer program is developed in " Mathematica " programming code to perform this analysis, based on the flowchart developed herein. The results obtained by the proposed procedure compare well with the recent studies and available field data. It is concluded that an iterative finite element approach, coupled with the nonlinear load transfer model, provides a simplified and practical procedure which is capable of predicting the dragload on single or group piles with reasonable accurac

A Secure Medical Record Sharing Scheme Based on Blockchain and Two-fold Encryption

Usually, a medical record (MR) contains the patients disease-oriented sensitive information. In addition, the MR needs to be shared among different bodies, e.g., diagnostic centres, hospitals, physicians, etc. Hence, retaining the privacy and integrity of MR is crucial. A blockchain based secure MR sharing system can manage these aspects properly. This paper proposes a blockchain based electronic (e-) MR sharing scheme that (i) considers the medical image and the text as the input, (ii) enriches the data privacy through a two-fold encryption mechanism consisting of an asymmetric cryptosystem and the dynamic DNA encoding, (iii) assures data integrity by storing the encrypted e-MR in the distinct block designated for each user in the blockchain, and (iv) eventually, enables authorized entities to regain the e-MR through decryption. Preliminary evaluations, analyses, comparisons with state-of-the-art works, etc., imply the efficacy of the proposed scheme.Comment: 6 pages, 3 tables, 8 figures, ICCIT 202

Organic Silicone Based Poly-Acrylate Binder Synthesis for Textile Pigment Printing

This present study deals about an organic silicone based poly-acrylate binder by using Emulsion Polymerization technique because it produces high molecular weight polymers, and there is no or negligible content of volatile organic compounds (VOC) for textile pigment printing. The binder was prepared by polymerizing hard monomers, soft monomers, functional monomers, and compound emulsifying agent, organic silicone, an initiator, pH adjustor and deionized water. Then the properties like sublimation test, durability test, fastness test, yellowness and softness testing were performed. The role of acrylic acid and Methyl methacrylate on the characterization of the polymers was detected and recorded. A material has been selected based on pervious study of different research and effect of silicone amount on film was observed

A Study to Detect Sentinel Lymph Node by Methylene Blue Dye and Histopathological Confirmation of Metastasis in Oral Squamous Cell Carcinoma Patient

Background: Oral Squamous Cell Carcinoma (OSCC) first metastasizes via lymphatic route and the first draining lymph node is Sentinel Lymph Node (SLN). SLN is identified by combine use of nuclear imaging and dye method, as nuclear imaging facility is expensive, not easily available and radioactive materials have more potential complications so dye alone can be an alternative.Aims: To assess the feasibility of using methylene blue dye (MBD) for detection of SLN in OSCC patient and using frozen section analysis to analyze metastatic status of SLN.Method: 20 patients with the histopathological diagnosis of OSCC, irrespective of stage underwent SLN identification by using a peritumoral injection of MBD. Surgery of neck was done first with reflection of subplatysmal flap to identify blue-stained node as SLN in the neck region and sent for frozen section analysis. Surgery was completed with primary resection and neck dissection. Histopathological analysis of SLN was done later.Results: SLN was identified in level Ib and II in 18 cases (identification rate=90%). The accuracy, sensitivity, specificity, PPV and NPV of SLN biopsy with frozen section analysis were 94%, 92.3%, 100%, 100%, 83.3% respectively.Conclusion: Methylene blue dye alone can be successfully used to detect sentinel lymph node in OSCC patient. SLN biopsy with frozen section analysis is sensitive enough to detect the metastatic status of regional lymph node