• The KIPS Transactions:PartA
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• v.15A no.4
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• pp.217-226
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• 2008

Branch prediction accuracy is critical for system performance in modern microprocessor architectures. The use of speculative update branch history provides substantial accuracy improvement in branch prediction. However, speculative update branch history is the information about uncommitted branch instruction and thus it may hurts program correctness, in case of miss-speculative execution. Therefore, speculative update branch history requires suitable recovery mechanisms to provide program correctness as well as performance improvement. In this paper, we propose recovery logics for speculative update branch history. The proposed solutions are recovery logics for both global history and local history. In simulation results, our solution provides performance improvement up to 5.64%. In addition, it guarantees the program correctness and almost 90% of additional hardware overhead is reduced, compared to previous works.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.11
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• pp.561-572
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• 2001

Since energy consumption of CMOS circuits has a quadratic dependency on the supply voltage, lowering the supply voltage is the most effective way of reducing energy consumption. We propose an intra-task voltage scheduling algorithm for low-energy hard real-time applications. Based on a static timing analysis technique, the proposed algorithm controls the supply voltage within an individual task boundary. By fully exploiting all the slack times, as scheduled program by the proposed algorithm always complete its execution near the deadline, thus achieving a high energy reduction ratio. In order to validate the effectiveness of the proposed algorithm, we built a software tool that automatically converts a DVS-unaware program into an equivalent low-energy program. Experimental results show that the low-energy version of an MPEG-4 encoder/decoder (converted by the software tool) consumes less than 7~25% of the original program running on a fixed-voltage system with a power-down mode.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.652-658
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• 2021

When acquiring a point cloud using a 3D scanner, a registration process of making the acquired data based on each local coordinate into one data with a unified world coordinate system is required. Its process is difficult to obtain a satisfactory result with only one execution, and it is repeated several times to increase the registration precision. The criterion for determining the registration accuracy is an important factor. The previous methods for determining the accuracy of registration have a limitation in that the judgment may be ambiguous in some cases, and different results may be produced each time depending on the characteristics of the point cloud. Therefore, to calculate the accuracy of registration more precisely, I propose a method using the average distance value of the point group for the entire points rather than the corresponding points used in the registration. When this method is used, it is possible to determine the registration accuracy more reliably than the conventional methods.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.117-128
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• 2024

In this paper, we propose a process for deriving priority tasks using the legal design technique in a situation where there is high uncertainty in the market and legal system regarding the commercialization of security tokens based on blockchain and distributed ledger technology. To issue and distribute securities tokens, we conducted a legal design workshop with participants who applied for innovative financial services (financial regulatory sandbox). During the workshop, participants harmonized their interests and deliberated on readiness, considering both legal and technical factors. The aim was to ascertain the feasibility of identifying prioritized objectives for future endeavors. The legal design technique facilitates consensus-building among stakeholders in an uncertain environment by confirming and adjusting differing perspectives and disagreements based on mutual understanding. The key stages include the empathetic process called "Family Therapy," the "N whys" for problem definition, and the speculative scenario design for problem-solving. This approach distinguishes itself from user-centered design thinking. Given the diverse stakeholders involved, effective facilitation by the facilitator is crucial during the legal design workshop preparation and execution.

• Hip & pelvis
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• v.36 no.2
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• pp.87-100
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• 2024

Total hip arthroplasty (THA) is an effective treatment for osteoarthritis, and the popularity of the direct anterior approach has increased due to more rapid recovery and increased stability. Instability, commonly caused by component malposition, remains a significant concern. The dynamic relationship between the pelvis and lumbar spine, deemed spinopelvic motion, is considered an important factor in stability. Various parameters are used in evaluating spinopelvic motion. Understanding spinopelvic motion is critical, and executing a precise plan for positioning the implant can be difficult with manual instrumentation. Robotic and/or navigation systems have been developed in the effort to enhance THA outcomes and for implementing spinopelvic parameters. These systems can be classified into three categories: X-ray/fluoroscopy-based, imageless, and computed tomography (CT)-based. Each system has advantages and limitations. When using CT-based systems, preoperative CT scans are used to assist with preoperative planning and intraoperative execution, providing feedback on implant position and restoration of hip biomechanics within a functional safe zone developed according to each patient's specific spinopelvic parameters. Several studies have demonstrated the accuracy and reproducibility of robotic systems with regard to implant positioning and leg length discrepancy. Some studies have reported better radiographic and clinical outcomes with use of robotic-assisted THA. However, clinical outcomes comparable to those for manual THA have also been reported. Robotic systems offer advantages in terms of accuracy, precision, and potentially reduced rates of dislocation. Additional research, including conduct of randomized controlled trials, will be required in order to evaluate the long-term outcomes and cost-effectiveness of robotic-assisted THA.

• Journal of Technology Innovation
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• v.22 no.4
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• pp.165-198
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• 2014

The national R&D performance evaluation system in Korea has been influenced by 'New Public Management' since the 1980s. The 1997 IMF crisis in Korea has necessitated the overhaul of S&T policy strategies in Korea. Reflecting this, effective distribution and utilization of S&T investment and resources has emerged as a crucial policy agenda, while expansionary investment in S&T maintained. During the period of 1999-2005, the R&D evaluation has been more focused on the input side and execution processes than on the results of R&D. Evaluation results were to be reflected in the budgeting of national R&D, but there were some disputes over how to make use of evaluation results between the budgeting ministry and the evaluation agency partly because they were two separate entities. After the advent of the new government(1998-2003) which advocated 'science and technology-oriented society', the national R&D evaluation system has evolved through a new legislation, the Performance Assessment Act, and the establishment of Science & Technology Innovation Agency to build up the unique framework for national R&D evaluation differentiated from the assessment system for general government investment programs. Most recently, due to 'Comprehensive Improvement Plan' in 2013, various components of national R&D evaluation seem to move on a new evolutionary track. For example, different types of evaluation are being developed and tried in accordance with differing evaluation goals, and the individual ministries and the research councils has got more enhanced autonomy and responsibility regarding R&D evaluation. So-called 'tailored' evaluation methods, taking into consideration the characteristics of programs and institutes / organizations to be evaluated, are now being tried. Competences of evaluation experts and agencies has also to be improved and strengthened.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.1
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• pp.29-36
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• 2017

In this paper, we implement a spatial big data analysis prototype based on Spark which is an in-memory system and compares the performance by the spatial split algorithm on this basis. In cluster computing environments, big data is divided into blocks of a certain size order to balance the computing load of big data. Existing research showed that in the case of the Hadoop based spatial big data system, the split method by spatial is more effective than the general sequential split method. Hadoop based spatial data system stores raw data as it is in spatial-divided blocks. However, in the proposed Spark-based spatial analysis system, there is a difference that spatial data is converted into a memory data structure and stored in a spatial block for search efficiency. Therefore, in this paper, we propose an in-memory spatial big data prototype and a spatial split block storage method. Also, we compare the performance of existing spatial split algorithms in the proposed prototype. We presented an appropriate spatial split strategy with the Spark based big data system. In the experiment, we compared the query execution time of the spatial split algorithm, and confirmed that the BSP algorithm shows the best performance.

• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.127-136
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• 2009

Modeling and Simulation, especially in mobile ad hoc network(MANET), are the most effective way to analyze performance or optimize system parameters without establishing real network environment. Focusing mainly on overall network behaviors in MANET concerns dynamics of network transport operations, which can efficiently be characterized with event based system states rather than execution details of protocols. We thus consider the network as a discrete event system to analyze dynamics of network transport performance. Zeigler's set-theoretic DEVS(Discrete Event Systems Specification) formalism can support specification of a discrete event system in hierarchical, modular manner. The DEVSim++ simulation environment can not only provide a rigorous modeling methodology based on the DEVS formalism but also support modelers to develop discrete event models using the hierarchical composition methodology in object-orientation. This environment however hardly supports to specify connection paths of network nodes, which are continuously altered due to mobility of nodes. This paper proposes a DEVS-based modeling and simulation methodology of enabling node mobility, and develops DEVS models for the mobile ad hoc network. We also simulate developed models with the DEVSim++ engine to verify the proposal.

• The KIPS Transactions:PartA
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• v.17A no.3
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• pp.127-136
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• 2010

A wireless sensor network(WSN) which roles as a mediator between living environment and computers in ubiquitous computing is very essential research area. Due to the constraint that sensor nodes should work in very resource-restricted circumstances, an operating system that can manage resources effectively is demanded. Also, a sensor network should be able to deal with many events quickly and simultaneously in order to respond to various physical changes in outer environment. The Sensor Network Operating System such as TinyOS, MANTIS and NanoQplus is much designed so that it can satisfy such requirement. But, for programmers who develop application program for sensor networks, they have lack of frameworks which the development is easily possible from restricted development environment. In this paper for this, we implemented a state machine framework apt for responsive systems in NanoQplus which is multi-thread-based sensor network operating system. In addition we propose an event broker module(EBM) for effective event dispatching, a message data structure for message sharing among state machines, and an execution module that handles messages and their queue and performs state transition of the machines. Furthermore, we could do the development more easily an application program with a state-based framework by developing CASE tools.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.289-297
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• 2014

This study is meaningful by offering basic data that is able to enhance satisfaction with the use of medical services by the qualified recipients of medical aid and to promote health consistently while looking into their satisfaction with the use of medical services, using independent variables for the period after the introduction of the selected medical center system. The study period from August 16, 2013 was 23 August, In conclusion, with a view to enhancing satisfaction with the use of medical services by qualified recipients of medical aid after the execution of the selected medical center system, it is most important to identify with greater sufficiency and accuracy the effect of medical services by qualified recipients of medical services and any unsatisfied desire for medical services. Also, in pursuit of the use of appropriate medical services, there is a need to prepare active cooperation between medical centers and various political alternatives of the government for the effective discovery of accessibility to medical services, overcome inefficiencies in administrative procedures, establish a reasonable medical service delivery system with the guarantee of appropriate medical treatment, and improve health management.