• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.3
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• pp.145-154
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• 2007

Dynamic update of kernel can change kernel functionality and fix bugs in runtime. Dynamic update is important because it leverages availability, reliability and flexibility of kernel. An instruction-granularity update technique has been used for dynamic update. However, it is difficult to apply update technique for a commodity operating system kernel because development and maintenance of update code must be performed with assembly language. To overcome this difficulty, we design the function-granularity dynamic update system which uses high-level language such as C language. The proposed update system makes the development and execution of update convenient by providing the development environment for update code which is same for kernel development. We implement this system for Linux and demonstrate an example of update for do_coredump() function which is reported it has a vulnerable point for security. The update was successfully executed.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.5
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• pp.223-230
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• 2008

Dynamic update of kernel can change kernel functionality and fix bugs in runtime. Dynamic update is important because it leverages availability, reliability and flexibility of kernel. An instruction-granularity update technique has been used for dynamic update. However, it is difficult to apply update technique for a commodity operating system kernel because development and maintenance of update code must be performed with assembly language. To overcome this difficulty, we design the function-granularity dynamic update system which uses high-level language such as C language. The proposed update system makes the development and execution of update convenient by providing the development environment for update code which is same for kernel development. We implement this system for Linux and demonstrate an example of update for EXT3 file system. The update was successfully executed.

• Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.15-20
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• 2016

The optimal estimation of a general continuous-discrete system can be achieved through the solution of the Fokker-Planck equation and the Bayesian update. Due the high nonlinearity of the equation of motion of the system and the measurement model, it is necessary to linearize the both equation. To avoid linearization, the filter based on Fokker-Planck equation is designed. with the unscented transformation update mechanism, in which the associated Fokker-Planck equation was solved efficiently and accurately via discrete quadrature and the measurement update was done through the unscented transformation update mechanism. This filter based on the Direct Quadrature Moment of Method(DQMOM) and the unscented transformation update is applied to the bearing only target tracking problem. The proposed filter can still provide more accurate estimation of the state than those of the extended Kalman filter especially when measurements are sparse. Simulation results indicate that the advantages of the proposed filter based on the DQMOM and the unscented transformation update make it a promising alternative to the extended Kalman filter.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.3
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• pp.163-169
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• 2013

This paper proposes a novel ECU (Electronic Control Units) update algorithm for AUTOSAR based automotive embedded system. The proposed algorithm provides fast and easy ECU update by extending AUTOSAR CAN Interface. The proposed system removes the update sequences from PDUR to RTE (ECU update program), and it stops other ISRs and operating system in order to reduce unnecessary context switching time. In experimental results, we can see that the proposed algorithm reduces update time.

• Journal of Internet Computing and Services
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• v.4 no.6
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• pp.87-93
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• 2003

Data Replication makes distributed system and database system improved in availability and performance. But it is difficult to keep strict consistency in data update. Existing algorithms keep strict consistency, but have problems of cost a great deal and delay time. It is to introduce hybrid update propagation algorithm which permits eager update for original copy and propagates lazy update for other copies. Hybrid update propagation algorithm also permits group update in ownership. This algorithm menages replica version in order to control group update consistency. Consistency and performance is improved by combining eager update and lazy update with group ownership. Simulation shows improvement of transaction throughput and response time depending on application and execution environment.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.6
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• pp.579-592
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• 2010

This paper presents a multi-phase model update approach for system identification of prestressed concrete (PSC) girders under various prestress forces. First, a multi-phase model update approach designed on the basis of eigenvalue sensitivity concept is newly proposed. Next, the proposed multi-phase approach is evaluated from controlled experiments on a lab-scale PSC girder for which forced vibration tests are performed for a series of prestress forces. On the PSC girder, a few natural frequencies and mode shapes are experimentally measured for the various prestress forces. The corresponding modal parameters are numerically calculated from a three-dimensional finite element (FE) model which is established for the target PSC girder. Eigenvalue sensitivities are analyzed for potential model-updating parameters of the FE model. Then, structural subsystems are identified phase-by-phase using the proposed model update procedure. Based on model update results, the relationship between prestress forces and model-updating parameters is analyzed to evaluate the influence of prestress forces on structural subsystems.

• International Journal of Contents
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• v.10 no.1
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• pp.62-67
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• 2014

Usually, cloud storage systems are developed based on DFS (Distributed File System) for scalability and reliability reasons. DFSs are designed to improve throughput than IO response time, and therefore, they are appropriate for batch processing jobs. Recently, cloud storage systems have been used for update intensive applications such as OLTP and so on. However, in DFSs, in-place update operations are not carefully considered. Therefore, when updates are frequent, I/O performance of DFSs are degraded significantly. DFSs with RAID techniques have been proposed to improve their performance and reliability. Their performance degradation caused by frequent update operations can be more significant. In this paper, we propose an in-place update method for DFS RAID exploiting a differential logging technique. The proposed method reduces the I/O costs, network traffic and XOR operation costs for RAID. We demonstrate the efficiency of our proposed in-place update method through various experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.588-591
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• 2009

In ubiquitous computing GIS services, it is possible to use the spatio-temporal data anytime through the mobile device. GIS services regularly update use the latest spatio-temporal data to provide the most suitable services. For this situation, update data is distributed to CD or wired networks update services. However, this method has problem to propagate update data to users as taking long time. In this paper, suggests a synchronization system which propagate update data to users for reducing processing time efficiently. This synchronization system collects update data in the field and synchronizes server with collected data to use mobile devices by real time. For this system, I design and materialize synchronization module which updates update data and wireless network module.

• Asia pacific journal of information systems
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• v.26 no.2
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• pp.268-289
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• 2016

While most of studies have paid attention to the initial adoption of a specific application, research on applications has not focused on an individual's update decision process. This study draws upon both dual information processing and status quo bias perspectives as a comprehensive theoretical lens to explain why individuals do not update their applications. This study assumes that individuals' inertia could be the main reason for their reluctance to update the applications. Based on a survey of 186 smartphone users, this study demonstrated that both habit as an affective trigger of system 1 thinking and sunk cost as a cognitive trigger of system 2 thinking promoted the two types of inertia (i.e., affective and cognitive based inertia) in individuals, which have a negative effect on their willingness to update their applications. By grounding the research model in a theoretical view, such as dual information processing and status quo bias, this study provides a unique theoretical lens from which to view individuals' behaviors, thereby gaining a better understanding of their decision not to update to the current version of applications. This study also investigates the moderating effect of the types of applications on the relationships between affective/cognitive-based inertia and willingness to update. Results show that both habit and sunk cost decrease the willingness to update because they increase both affective and cognitive-based inertia. This study also found that the effects of affective/cognitive based inertia differed depending on the type of applications.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.1
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• pp.37-48
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• 2011

Sensor networks monitor the environment, collect sensed data, and relay the data back to a collection point. Although sensor nodes have very limited hardware resources, they require an operating system that can provide efficient resource management and various application environments. In addition, the wireless sensor networks require the code update previously deployed to patch bugs in program and to improve performance of kernel service routines and application programs. This paper presents EPRCU (Easy to Perform Remote Code Update), a new operating system for wireless sensor nodes, which has enhanced functionalities to perform remote code update. To achieve an efficient code update, the EPRCU provides dynamic memory allocation and program memory management. It supports the event-driven kernel, which uses priority-based scheduling with the application of aging techniques. Therefore, the proposed operating system is not only easy to perform wireless communication with the remote code update but also suitable for various sensor network applications.