中国地方政府の金融リスクに関する研究

Tohoku University鈴木賢一課

Research on Cutting Force of Turn-Milling Based on Thin-Walled Blade

Turn-milling is regarded as the milling of a curved surface while rotating the workpiece around its center point, which combines effectively the advantages of both turning and milling, wherein it allows for good metal removal with the difficult-to-cut thin-walled workpieces in aviation. The objective of the present work is to study cutting force by turn-milling in cutting condition. Aiming at the deformation properties of thin-walled blade, the predicted models of rigid cutting force and flexible cutting force with ball cutter are provided, respectively, in turn-milling process. The deformation values of blade and cutter are calculated, respectively, based on the engaged trajectory by using the iterative algorithm. The rigid and flexible cutting forces are compared and the influence degrees of cutting parameters on cutting forces are analyzed. These conclusions provide theoretical foundation and reference for turn-milling mechanism research

Research on dynamic performance and motion control of robot manipulator

Amongst the robotics and autonomous systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. In this paper, the purpose is to research on dynamic performance and motion control of robot manipulator for the more precise, crucial and critical tasks in industry. Firstly, the forward and inverse kinematics was accurately described by obtaining the link transformation matrices from each joint in robot manipulator. To find admissible solutions along the path, the workspace of the manipulator was determined by joint limit condition and validated by actual measurement. And then, the dynamic performance of robot manipulator is researched by using the forming flexible multi-body system. Furthermore, the frequency response curves are obtained by exciting vibration simulation based on vibration model, which the predicted method was validated by comparing simulation and experimental results. Finally, the control system architecture was given and the grasping process was conducted by gripper based on motion trajectory control in the workspace

A Programmable ROADM System for SDM/WDM Networks

This paper proposed and evaluated a programmable ROADM system for MCF-based SDM/WDM networks. The proposed ROADM system employing both bypass connection and Route-and-Select wavelength switching enables adaptable virtual topology in optical networks by dynamically configuring bypass connection cores. The simulation results confirmed this ROADM system could provide acceptable performance with an around 10–20% reduction in the total cost including the number of ports and WSSs by comparing with a fully flexible SDM/WDM ROADM system, which cannot be implemented due to the required extremely high-port-count WSSs

Product Search Algorithm Based on Improved Ant Colony Optimization in a Distributed Network

The crowd intelligence-based e-commerce transaction network (CIeTN) is a distributed and unstructured network structure. Smart individuals, such as buyers, sellers, and third-party organizations, can store information in local nodes and connect and share information via moments. The purpose of this study is to design a product search algorithm on the basis of ant colony optimization (ACO) to achieve an efficient and accurate search for the product demand of a node in the network. We introduce the improved ideas of maximum and minimum ants to design a set of heuristic search algorithms on the basis of ACO. To reduce search blindness, additional relevant heuristic factors are selected to define the heuristic calculation equation. The pheromone update mechanism integrating into the product matching factor and forwarding probability is used to design the network search rules among nodes in the search algorithm. Finally, the search algorithm is facilitated by Java language programming and PeerSim software. Experimental results show that the algorithm has significant advantages over the flooding method and the random walk method in terms of search success rate, search time, product matching, search network consumption, and scalability. The search algorithm introduces the idea of improving the maximum and minimum ant colony system and proposes new ideas in the design of heuristic factors in the heuristic equation and the pheromone update strategy. The search algorithm can search for product information effectively

Compatible Remediation on Vulnerabilities from Third-Party Libraries for Java Projects

With the increasing disclosure of vulnerabilities in open-source software, software composition analysis (SCA) has been widely applied to reveal third-party libraries and the associated vulnerabilities in software projects. Beyond the revelation, SCA tools adopt various remediation strategies to fix vulnerabilities, the quality of which varies substantially. However, ineffective remediation could induce side effects, such as compilation failures, which impede acceptance by users. According to our studies, existing SCA tools could not correctly handle the concerns of users regarding the compatibility of remediated projects. To this end, we propose Compatible Remediation of Third-party libraries (CORAL) for Maven projects to fix vulnerabilities without breaking the projects. The evaluation proved that CORAL not only fixed 87.56% of vulnerabilities which outperformed other tools (best 75.32%) and achieved a 98.67% successful compilation rate and a 92.96% successful unit test rate. Furthermore, we found that 78.45% of vulnerabilities in popular Maven projects could be fixed without breaking the compilation, and the rest of the vulnerabilities (21.55%) could either be fixed by upgrades that break the compilations or even be impossible to fix by upgrading.Comment: 11 pages, conferenc

Prediction of protein structural class with Rough Sets

BACKGROUND: A new method for the prediction of protein structural classes is constructed based on Rough Sets algorithm, which is a rule-based data mining method. Amino acid compositions and 8 physicochemical properties data are used as conditional attributes for the construction of decision system. After reducing the decision system, decision rules are generated, which can be used to classify new objects. RESULTS: In this study, self-consistency and jackknife tests on the datasets constructed by G.P. Zhou (Journal of Protein Chemistry, 1998, 17: 729–738) are used to verify the performance of this method, and are compared with some of prior works. The results showed that the rough sets approach is very promising and may play a complementary role to the existing powerful approaches, such as the component-coupled, neural network, SVM, and LogitBoost approaches. CONCLUSION: The results with high success rates indicate that the rough sets approach as proposed in this paper might hold a high potential to become a useful tool in bioinformatics

Cause of angular distortion in fusion welding: asymmetric cross-sectional profile along thickness

Angular distortion is a common problem in fusion welding, especially when it comes to thick plates. Despite the fact that various processes and influencing factors have been discussed, the cause of the angular distortion has not been clearly revealed. In this research, the asymmetry of cross-sectional profile along thickness is considered of great importance to the angular distortion. A theoretical model concerning the melting-solidification process in fusion welding was established. An expression of the angular distortion was formulated and then validated by experiments of laser welding 316L stainless steel. The results show that the asymmetric cross-sectional profile is a major contributory factor towards the angular distortion mechanism. The asymmetry of cross-section profile along thickness causes the difference between two bending moments in the lower and upper parts of the joint. This is the difference that drives the angular distortion of the welded part. Besides, the asymmetry of cross-section profile is likely to be influenced by various processes and parameters, thereby changing the angular distortion