• Journal of Korean Neurosurgical Society
• /
• v.57 no.1
• /
• pp.58-60
• /
• 2015

A 15-year-old female patient with progressive pulsatile exophthalmos caused by intraorbital encephalocele was evaluated with computed tomography (CT) and magnetic resonance imaging (MRI) in our clinic. She had no history of trauma or reconstructive surgery. When she was a little girl, she had undergone surgery for congenital glaucoma on the right eye. On the three-dimensional image of CT, a hypoplasic bone defect was observed in the greater wing of the right sphenoid bone. MRI and CT scan showed herniation through this defect of the arachnoid membrane and protruded cerebral tissue into the right orbita. Intraorbital encephalocele is an important entity that can cause pulsatile exophthalmos and blindness.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.23 no.3
• /
• pp.267-282
• /
• 2019

This paper examines how one can build a block tridiagonal structure for k-almost normal matrices and also for k-almost conjugate normal matrices. We shall see that these representations are created by unitary similarity and unitary congruance transformations, respectively. It shall be proven that the orders of diagonal blocks are 1, k + 2, 2k + 3, ${\ldots}$, in both cases. Then these block tridiagonal structures shall be reviewed for the cases where the mentioned matrices satisfy in a second-degree polynomial. Finally, for these processes, algorithms are presented.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.13 no.6
• /
• pp.279-288
• /
• 2018

As a result of the technological advances in the E / E system, automotive system can provide advanced functions for safety and comfort. In addition, mechanical systems is changed to the electronic system. And the systems perform cooperative functions through communication. So the E / E system becomes more complicated as the size of the system increases. In order to secure the safety of complicated E / E system, ISO26262 standard require that Freedom from Interference and Sufficient Independence be met. In this paper, we propose a software scheduling method that can guarantee the independence between decomposed components after software decomposition and software development of ASIL D level EPB (Electronic Parking Brake) system.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.24 no.4
• /
• pp.375-385
• /
• 2020

In this paper, a special indefinite inner product, named hyperbolic scalar product, is used and all acquired results have been raised and proved with the proviso that the space is equipped with this indefinite scalar product. The main objective is to be introduced and applied an indefinite oblique projection method, called Indefinite Lanczos J-biorthogonalizatiom process, which in addition to building a pair of J-biorthogonal bases for two used Krylov subspaces, leads to the introduction of a process for solving large non-J-symmetric linear systems, i.e., Indefinite two-sided Lanczos Algorithm for Linear systems.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.2_1
• /
• pp.239-248
• /
• 2023

In this paper, we conduct a study on the design that can secure the safety of the EPLA system by performing safety activities based on the ISO 26262 standard for vehicle functional safety. In the case of a company developing a detailed system, it is responsible for verification through hardware design and safety analysis in the overall flow of safety activities, and safety analysis according to the ASIL safety level must be properly performed. At this time, there are cases where the safety goal quantitative metric value suggested by the ISO 26262 standard cannot be satisfied only by the hardware design of the basic function, so it is necessary to design and install the safety mechanism. Based on ISO 26262 safety activities, it is possible to derive an effective design plan through hardware safety analysis.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.6
• /
• pp.222-234
• /
• 2020

Autonomous vehicles are equipped with a wide rage of sensors such as GPS, RADAR, LIDAR, camera, IMU, etc. and are driven by recognizing and judging various transportation systems at intersections in the city. The accident ratio of the intersection of the autonomous vehicles is 88% of all accidents due to the limitation of prediction and judgment of an area outside the sensing distance. Not only research on non-signalized intersection collision avoidance strategies through V2V and V2I is underway, but also research on safe intersection driving in failure situations is underway, but verification and fragments through simple intersection scenarios Only typical V2V failures are presented. In this paper, we analyzed the architecture of the V2V module, analyzed the causal factors for each V2V module, and defined the failure mode. We presented intersection scenarios for various road conditions and traffic volumes. we used the ISO-26262 Part3 Process and performed HARA (Hazard Analysis and Risk Assessment) to analyze the risk of autonomous vehicle based on the simulation. We presented ASIL, which is the result of risk analysis, proposed a monitoring concept for each component of the V2V module, and presented monitoring coverage.

• Smart Structures and Systems
• /
• v.20 no.1
• /
• pp.99-114
• /
• 2017

In cognitive science, it is illustrated how the collective opinions of a group of individuals answers to questions involving quantity estimation. One example of this approach is introduced in this article as Star Graph (SG) algorithm. This graph describes the details of communication among individuals to share their information and make a new decision. A new labyrinthine network of neighbors is defined in the decision-making process of the algorithm. In order to prevent getting trapped in local optima, the neighboring networks are regenerated in each iteration of the algorithm. In this algorithm, the normal distribution is utilized for a group of agents with the best results (guidance group) to replace the existing infeasible solutions. Here, some new functions are introduced to provide a high convergence for the method. These functions not only increase the local and global search capabilities but also require less computational effort. Various benchmark functions and engineering problems are examined and the results are compared with those of some other algorithms to show the capability and performance of the presented method.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.4
• /
• pp.1915-1920
• /
• 2015

ISO 26262 is an international standard for the functional safety of electric and electronic systems in vehicles, and this standard has become a major issue in the automotive industry. In this paper, a functional safety compliant electronic control unit (ECU) for an electric power steering (EPS) system and a demonstration purposed EPS system are developed, and a software and hardware structure for a safety critical system is presented. EPS is the most recently introduced power steering technology for vehicles, and it can improve driver’s convenience and fuel efficiency. In conformity with the design process specified in ISO 26262, the Automotive Safety Integrity Level (ASIL) of an EPS system is evaluated, and hardware and software are designed based on an asymmetric dual processing unit architecture and an external watchdog. The developed EPS system effectively demonstrates the fault detection and diagnostic functions of a functional safety compliant ECU as well as the basic EPS functions.

• Structural Engineering and Mechanics
• /
• v.65 no.6
• /
• pp.707-719
• /
• 2018

In this article, a new method is introduced to improve the local search capability of meta-heuristic algorithms using the projection of the path on the border of constraints. In a mathematical point of view, the Gradient Projection Method is applied through a new approach, while the imposed limitations are removed. Accordingly, the gradient vector is replaced with a new meta-heuristic based vector. Besides, the active constraint identification algorithm, and the projection method are changed into less complex approaches. As a result, if a constraint is violated by an agent, a new path will be suggested to correct the direction of the agent's movement. The presented procedure includes three main steps: (1) the identification of the active constraint, (2) the neighboring point determination, and (3) the new direction and step length. Moreover, this method can be applied to some meta-heuristic algorithms. It increases the chance of convergence in the final phase of the search process, especially when the number of the violations of the constraints increases. The method is applied jointly with the authors' newly developed meta-heuristic algorithm, entitled Star Graph. The capability of the resulted hybrid method is examined using the optimal design of truss and frame structures. Eventually, the comparison of the results with other meta-heuristics of the literature shows that the hybrid method is successful in the global as well as local search.

• Structural Engineering and Mechanics
• /
• v.61 no.1
• /
• pp.65-76
• /
• 2017

Prediction of the characteristics of both in-plane and out-of-plane elastic waves within conducting nanoplates in the presence of bidirectionally in-plane magnetic fields is of interest. Using Lorentz's formulas and nonlocal continuum theory of Eringen, the nonlocal elastic version of the equations of motion is obtained. The frequencies as well as the corresponding phase and group velocities pertinent to the in-plane and out-of-plane waves are analytically evaluated. The roles of the strength of in-plane magnetic field, wavenumber, wave direction, nanoplate's thickness, and small-scale parameter on characteristics of waves are discussed. The obtained results show that the in-plane frequencies commonly grow with the in-plane magnetic field. However, the transmissibility of the out-of-plane waves rigorously depends on the magnetic field strength, direction of the propagated transverse waves, small-scale parameter, and thickness of the nanoplate. The criterion for safe transferring of the out-of-plane waves through the conducting nanoplate immersed in a bidirectional magnetic field is also explained and discussed.