• Korean Journal of Remote Sensing
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• v.20 no.6
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• pp.409-418
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• 2004

LOD is a widely used technique in 3D game and animation to represent large 3D data sets smoothly in real-time. Most LOD algorithms use a binary tree to keep the ancestor information. A new algorithm proposed in this paper, however, do not keep the ancestor information, thus use the less memory space and rather increase the rendering performance. To verify the efficiency of the proposed algorithm, performance comparison with ROAM is conducted in real-time 3D terrain navigation. Result shows that the proposed algorithm uses about 1/4 of the memory space of ROAM and about 4 times faster than ROAM.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.1
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• pp.75-81
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• 2023

In this study, we design an optimized Graphics Processing Unit (GPU)-based GNSS signal processing technique with the goal of designing and implementing a GNSS Software Defined Receiver (SDR) that can operate in real time all-in-view mode under multi-constellation and multi-frequency signal environment. In the proposed structure the correlators of the existing GNSS SDR are processed by the GPU. We designed a memory structure and processing method that can minimize memory access bottlenecks and optimize the GPU memory resource distribution. The designed GNSS SDR can select and operate only the desired GNSS or desired satellite signals by user input. Also, parameters such as the number of quantization bits, sampling rate, and number of signal tracking arms can be selected. The computing capability of the designed GPU-based GNSS SDR was evaluated and it was confirmed that up to 2400 channels can be processed in real time. As a result, the GPU-based GNSS SDR has sufficient performance to operate in real-time all-in-view mode. In future studies, it will be used for more diverse GNSS signal processing and will be applied to multipath effect analysis using more tracking arms.

• The Journal of Information Technology and Database
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• v.1 no.2
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• pp.103-125
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• 1994

In this paper, we introduce a new main memory storage system called FLASH that is designed for real-time applications. The FLASH system is characterized by the memory residency of data and a new fast and dynamic hashing scheme called extendible chained bucket hashing. We compared the performance of the new hashing algorithm with other well-known ones. Also, we carried out an experiment to compare the overall performance of the FLASH system with a commercial one. Both comparison results show that the new hashing scheme and the FLASH system outperforms other competitives.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.628-630
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• 2004

실시간 운영체제가 탑재되는 임베디드 시스템의 공간제약 특성상 한정된 자원을 가질 수밖에 없기 때문에 자원의 효율적인 사용 및 관리가 필수적이다. 특히 CPU 와 함께 한정된 크기의 메모리는 운영체제의 중요한 자원으로, 효율적인 메모리 관리를 통해 시스템의 성능을 향상시킬 수 있다. 본 논문에서는 실시간 운영체제의 동적 메모리 관리기법 중 메모리 풀에서의 메모리 누수 방지 기법을 설계 및 구현하였다

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.89-94
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• 1989

In this paper, we propose a hybrid optical/digital version of the associative memory which improve hardware efficiency and increase convergence rates. Multifocus hololens are used as space-varient optical element for performing inner product and summation function. The real-time input and the stored states of memory matrix is formated using LCTV. One method of adaptively changing the weights of stored vectors during each iteration is implemented electronically. A design for a optical implementation scheme is discussed and the proposed architecture is demonstrated the ability of retrieving with computer simmulation.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.414-417
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• 1997

Many small-sized real-time kernels do not provide memory management and device drivers, not to mention file management. In this paper, we propose a design and implementation of TCP/IP protocol stack for such small real-time kernels based on [6] where we studied issues to be considered for porting the functionalities of TCP/IP for such small real-time kernels.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.11-22
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• 2004

As random access memory chip gets cheaper, it becomes affordable to realize main memory-based database systems. Consequently, reducing cache misses emerges as the most important issue in current main memory databases, in which CPU speeds have been increasing at 60% per year, compared to the memory speeds at 10% per you. In this paper, we design and implement a main-memory database system for real-time mobile GIS. Our system is composed of 5 modules： the interface manager provides the interface for PDA users； the memory data manager controls spatial and non-spatial data in main-memory using virtual memory techniques； the query manager processes spatial and non-spatial query : the index manager manages the MR-tree index for spatial data and the T-tree index for non-spatial index : the GIS server interface provides the interface with disk-based GIS. The MR-tree proposed propagates node splits upward only if one of the internal nodes on the insertion path has empty space. Thus, the internal nodes of the MR-tree are almost 100% full. Our experimental study shows that the two-dimensional MR-tree performs search up to 2.4 times faster than the ordinary R-tree. To use virtual memory techniques, the memory data manager uses page tables for spatial data, non- spatial data, T-tree and MR-tree. And, it uses indirect addressing techniques for fast reloading from disk.

• The KIPS Transactions:PartA
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• v.11A no.7 s.91
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• pp.475-482
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• 2004

We live in the flood of information due to advancement of information communication and increase of E-mail. Managing users huge in-formation systematically and speedy searching are needed in these social advancement. In this thesis, in order to satisfy these requirement, We suggested Real-time LDAP Interface using Main Memory Resident Database Management System which can manage a lot of information fast systematically. It is expected that system can provide advantage of performance improvement through replacing Main Memory Resident Database Management System without change of application which is required high speed process.

• The Journal of Society for e-Business Studies
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• v.14 no.4
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• pp.119-131
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• 2009

During a decade, e-Commerce environments supporting real-time transaction processing have been getting larger. In telecommunication and financial environments, research and building for main memory database systems have been doing to support real-time transaction processing. A research on indexing for fast transaction support focuses on reducing cache misses or reducing memory access latency when cache misses happen. In the paper, we propose a prefetch method for tree index structures to reduce memory access latency. We present a prefetch-efficient pCST-tree and show superiority of the proposed tree by experiments.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.127-141
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• 2009

While the ever-increasing complexity of automotive software systems can be effectively managed through the adoption of a reliable real-time operating system (RTOS), it may incur additional resource usage to a resultant system. Due to the mass production nature of the automotive industry, reducing physical resources used by automotive software is of the utmost importance for cost reduction. OSEK OS is an automotive real-time kernel standard specifically defined to address this issue. Thus, it is very important to develop and exploit kernel mechanisms such that they can achieve minimal resource usage in the OSEK OS implementation. In this paper, we analyze the task subsystem, resource subsystem, application mode and conformance classes of OSEK OS as well as the OSEK Implementation Language (OIL). Based on our analysis, we in turn devise and implement kernel mechanisms to minimize the dynamic memory usage of the OSEK OS implementation. Finally, we show that our mechanisms effectively reduce the memory usage of OSEK OS and applications.