• ETRI Journal
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• v.45 no.3
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• pp.462-478
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• 2023

In quantum computing, the use of Pauli frames through software traces of classical computers improves computation efficiency. In previous studies, error correction and Pauli operation tracking have been performed simultaneously using integrated Pauli frames in the physical layer. In such a complex processing structure, the number of simultaneous operations processed in the physical layer exponentially increases as the distance of the surface code encoding logical qubit increases. This study proposes a Pauli frame management architecture partitioned into two layers for a lattice surgery-based surface code and describes its structure and operation rules. To evaluate the effectiveness of our method, we generated a random circuit according to the gate ratios constituting the commonly known quantum circuits and compared the generated circuit with the existing Pauli frame and our method. Simulations show a decrease of about 5% over traditional methods. In the case of experiments that only increase the code distance of the logical qubit, it can be seen that the effect of reducing the physical operation through the logical Pauli frame becomes more important.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.5
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• pp.1051-1058
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• 2024

In semiconductors for AI, Computing in Memory (CIM) integrates computation and memory to minimize data movement and reduce processing bottlenecks, thereby improving performance. In AI tasks that handle large amounts of data, CIM is gaining attention as a key technology that optimizes the performance of AI systems by improving power efficiency and enabling faster computation. In this paper, a new CIM architecture for AI semiconductors is proposed. The proposed architecture can perform MAC operations by controlling the width of the transistor and the pulse width of the control signal, and can be implemented in a smaller area than the existing architecture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2648-2668
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• 2016

Modern mobile devices are equipped with various accelerated processing units to handle computationally intensive applications; therefore, Open Computing Language (OpenCL) has been proposed to fully take advantage of the computational power in heterogeneous systems. This article introduces a parallel software decoder of Low Density Parity Check (LDPC) codes on an embedded heterogeneous platform using an OpenCL framework. The LDPC code is one of the most popular and strongest error correcting codes for mobile communication systems. Each step of LDPC decoding has different parallelization characteristics. In the proposed LDPC decoder, steps suitable for task-level parallelization are executed on the multi-core central processing unit (CPU), and steps suitable for data-level parallelization are processed by the graphics processing unit (GPU). To improve the performance of OpenCL kernels for LDPC decoding operations, explicit thread scheduling, vectorization, and effective data transfer techniques are applied. The proposed LDPC decoder achieves high performance and high power efficiency by using heterogeneous multi-core processors on a unified computing framework.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.129-138
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• 2015

In this study, the road construction field of high impact in the construction industry were selected, and the analysis of the detailed technology level was carried out. and we derived the main fields for future overseas. As results, the technology level of road facilities in korea was high about road operations and management sector, while it was relatively row about road pavements. And this study, we analyzed the economic, social and technological priority, and derived main fields to have the high investment efficiency. A derived items are found to be "maintenance-free Modular Road Pavements" and "Cities temperature reduction-type road".

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.42-47
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• 2016

The quality of CAD models affects the efficiency of the product development process. However, it seems that CAD modeling education in colleges simply focuses on the creation of CAD models without considering the quality or the applicability of the models. In this paper, we propose educational modeling approaches to help improve the quality and applicability of CAD models. These methods teach students to create models that include a rich set of information, facilitate downstream applications, and are precisely made with the fewest operations. A survey was carried out with students to validate these approaches.

• Korean Management Science Review
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• v.32 no.1
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• pp.49-63
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• 2015

This paper investigates an aircraft-target assignment problem in consideration of deconfliction. The aircraft-target assignment problem is the problem to assign available aircrafts and weapons to targets that should be attacked, where the objective function is to minimize the total expected damage of aircrafts. Deconfliction is the way of dividing airspaces for aircraft flight to ensure the safety while performing the mission. In this paper, mixed integer programming model is suggested, where it considers deconfliction between aircrafts. However, the suggested MIP model is non-linear and limited to get solution for large size problem. The 2-phase decomposition model is suggested for efficiency and computation, where in the first phase target area is divided into sectors for deconfliction and in the second phase aircrafts and weapons are assigned to given targets for minimizing expected damage of aircraft. The proposed decomposition model shows outperforms the model developed for comparison in the computational experiment.

• Journal of the Korean Solar Energy Society
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• v.36 no.4
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• pp.31-40
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• 2016

The demands for photovoltaic systems on a large scale have grown dramatically and require new technologies to get the high efficiency and reliable operations of power conversion systems. These needs can be realized by the cost-effective and high performance digital revolutions and faster semiconductor switching devices. However, the new power systems have been more sophisticated and their reliability becomes critical issues. In this paper, a new fault-tolerance power conversion scheme for the photovoltaic systems is proposed. The proposed fault-tolerant scheme is able to supply energy from solar panels to loads intermittently in spite of a front boost converter open failure, and its voltage and current controllers are designed to improve the transient performance by using an average model design scheme. The proposed approach is verified both by simulations. The results will enable more timely and wide usage of alternative/renewable energy systems resulting in increased energy security.

• Korean Journal of Computational Design and Engineering
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• v.10 no.1
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• pp.27-39
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• 2005

Implicit surfaces are geometric shapes which are defined by implicit functions and exist in three-dimensional space. Recently, implicit surfaces have received much attention in solid modeling applications because they are easy to represent the location of points and to use boolean operations. However, it is difficult to chart points on implicit surfaces for rendering. As efficient rendering method of implicit surfaces, the original Adaptively Sampled Distance Fields (ADFs) $method^{[1]}$ is to use sampled distance fields which subdivide the three dimensional space of implicit surfaces into many cells with high sampling rates in regions where the distance field contains fine detail and low sampling rates where the field varies smoothly. In this paper, in order to maintain the sharp features efficiently with small number of cells, an extended ADFs method is proposed, applying the Dual/Primal mesh optimization $method^{[2]}$ to the original ADFs method. The Dual/Primal mesh optimization method maintains sharp features, moving the vertices to tangent plane of implicit surfaces and reconstructing the vertices by applying a curvature-weighted factor. The proposed extended ADFs method is applied to several examples of implicit surfaces to evaluate the efficiency of the rendering performance.

• Korean Management Science Review
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• v.19 no.1
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• pp.75-88
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• 2002

In recent years, it Is necessary to develop an alternative measure, the time efficiency of management activities, as a more measurable and operational tool Instead of traditional accounting measures such as inventories turnover. Therefore the concept of throughput time has got much attention as useful tool for controlling time based management. The purpose of this paper is to investigate the usefulness and adaptability of throughput time. The sample consists of 212 non-banking firms listed on the Korean Stock Exchange. The test Period were 10 years(1989-1998). The regression analysis for this study was performed using the cross-sectional data for the sample, and it was also performed for each Industry. The results show that net Income to tonal assets and labor productivity (value added Per employee) variables in the model was signiflcantly associated with throughput time. On the other hand, the relationship between throughput time and logistics cost to sales do largely not have statistical significance. Especially, it is found that the relationship do not have significance or negative response in food & beverage industry and wholesale & retail industry. In summary, the results show that the measure of throughput time can be an effective managerial Indicator for time based competition and management.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.681-686
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• 2003

In recent years automatic image indexing and retrieval have been increasingly studied. However, content-based retrieval techniques for general images are still inadequate for many purposes. The novelty and originality of this thesis are the definition and use of a spatial information model as a contribution to the accuracy and efficiency of image search. In addition, the model is applied to represent color and shape image contents as a vector using the method of image features extraction, which was inspired by the previous work on the study of human visual perception. The indexing scheme using the color, shape and spatial model shows the potential of being applied with the well-developed algorithms of features extraction and image search, like ranking operations. To conclude, user can retrieved more similar images with high precision and fast speed using the proposed system.