• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1306-1313
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• 2018

The randomness and incipient nature of certain faults in reactor systems warrant a robust and dynamic detection mechanism. Existing models and methods for fault diagnosis using different mathematical/statistical inferences lack incipient and novel faults detection capability. To this end, we propose a fault diagnosis method that utilizes the flexibility of data-driven Support Vector Machine (SVM) for component-level fault diagnosis. The technique integrates separately-built, separately-trained, specialized SVM modules capable of component-level fault diagnosis into a coherent intelligent system, with each SVM module monitoring sub-units of the reactor coolant system. To evaluate the model, marginal faults selected from the failure mode and effect analysis (FMEA) are simulated in the steam generator and pressure boundary of the Chinese CNP300 PWR (Qinshan I NPP) reactor coolant system, using a best-estimate thermal-hydraulic code, RELAP5/SCDAP Mod4.0. Multiclass SVM model is trained with component level parameters that represent the steady state and selected faults in the components. For optimization purposes, we considered and compared the performances of different multiclass models in MATLAB, using different coding matrices, as well as different kernel functions on the representative data derived from the simulation of Qinshan I NPP. An optimum predictive model - the Error Correcting Output Code (ECOC) with TenaryComplete coding matrix - was obtained from experiments, and utilized to diagnose the incipient faults. Some of the important diagnostic results and heuristic model evaluation methods are presented in this paper.

• Journal of Korea Water Resources Association
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• 제51권11호
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• pp.1011-1020
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• 2018

This study aims to develop a drought monitoring scheme based on groundwater which can be exploit for water supply under drought stress. In this context, groundwater level can be used as a proxy for better understanding the temporal evolution of drought state. First, kernel density estimator is presented in the monthly groundwater level over the entire national groundwater stations. The estimated cumulative distribution function is then utilized to map the monthly groundwater level into the standardized groundwater level index (SGI). The SGI for each station was eventually converted into the index for major cities through the Thiessen polygon approach. We provide a drought classification for a given SGI to better characterize the degree of drought condition. Ultimately, we conclude that the proposed monitoring framework enables a more reliable estimation of the drought stress, especially for a limited water supply area.

• The Journal of the Korea Contents Association
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• 제11권7호
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• pp.51-59
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• 2011

Intelligent service robots leading the future market are robots which assist humans physically, mentally, and emotionally. Since intelligent service robots operate in a tightly coupled manner with humans, their safe operation should be an inevitable consideration. For this safety, real-time capabilities are necessary to execute certain services periodically. Currently, most robot components are being developed based on Windows for the sake of development convenience. However, since Windows does not support real-time, there is no option but to use expensive third-party software such as RTX and INTime. Also since most robot components are usually execute in user-level, we need to research how to support real-time in user-level. In this paper, we design and implement how to support real-time for components running in user-level on Windows using RTiK which actually supports real-time in kernel level on Windows.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제29권1C호
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• pp.102-110
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• 2004

In this paper, we propose a VLSI structure of real-time image compression and reconstruction processor using 2-D discrete wavelet transform and implement into a hardware which use minimal hardware resource using ASIC library. In the implemented hardware, Data path part consists of the DWT kernel for the wavelet transform and inverse transform, quantizer/dequantizer, the huffman encoder/huffman decoder, the adder/buffer for the inverse wavelet transform, and the interface modules for input/output. Control part consists of the programming register, the controller which decodes the instructions and generates the control signals, and the status register for indicating the internal state into the external of circuit. According to the programming condition, the designed circuit has the various selective output formats which are wavelet coefficient, quantization coefficient or index, and Huffman code in image compression mode, and Huffman decoding result, reconstructed quantization coefficient, and reconstructed wavelet coefficient in image reconstructed mode. The programming register has 16 stages and one instruction can be used for a horizontal(or vertical) filtering in a level. Since each register automatically operated in the right order, 4-level discrete wavelet transform can be executed by a programming. We synthesized the designed circuit with synthesis library of Hynix 0.35um CMOS fabrication using the synthesis tool, Synopsys and extracted the gate-level netlist. From the netlist, timing information was extracted using Vela tool. We executed the timing simulation with the extracted netlist and timing information using NC-Verilog tool. Also PNR and layout process was executed using Apollo tool. The Implemented hardware has about 50,000 gate sizes and stably operates in 80MHz clock frequency.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제27권3호
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• pp.137-145
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• 2014

We present a design sensitivity analysis(DSA) method for multiscale problems based on bridging scale decomposition. In this paper, we utilize a bridging scale method for the coupled system analysis. Since the analysis of full MD systems requires huge amount of computational costs, a coupled system of MD-level and continuum-level simulation is usually preferred. The information exchange between the MD and continuum levels is taken place at the MD-continuum boundary. In the bridging scale method, a generalized Langevin equation(GLE) is introduced for the reduced MD system and the GLE force using a time history kernel is applied at the boundary atoms in the MD system. Therefore, we can separately analyze the MD and continuum level simulations, which can accelerate the computing process. Once the simulation of coupled problems is successful, the need for the DSA is naturally arising for the optimization of macro-scale design, where the macro scale performance of the system is maximized considering the micro scale effects. The finite difference sensitivity is impractical for the gradient based optimization of large scale problems due to the restriction of computing costs but the analytical sensitivity for the coupled system is always accurate. In this study, we derive the analytical design sensitivity to verify the accuracy and applicability to the design optimization of the coupled system.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제31권4호
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• pp.701-713
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• 2021

Race Condition is a vulnerability in which two or more processes input or manipulate a common resource at the same time, resulting in unintended results. This vulnerability can lead to problems such as denial of service, elevation of privilege. When a vulnerability occurs in software, the relevant information is documented, but often the cause of the vulnerability or the source code is not disclosed. In this case, analysis at the binary level is necessary to detect the vulnerability. This paper aims to detect the Time-Of-Check Time-Of-Use (TOCTOU) Race Condition vulnerability of UNIX kernel-based File System at the binary level. So far, various detection techniques of static/dynamic analysis techniques have been studied for the vulnerability. Existing vulnerability detection tools using static analysis detect through source code analysis, and there are currently few studies conducted at the binary level. In this paper, we propose a method for detecting TOCTOU Race Condition in File System based on Control Flow Graph and Call Graph through Binary Analysis Platform (BAP), a binary static analysis tool.

• Journal of Biosystems Engineering
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• 제34권6호
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• pp.439-445
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• 2009

This study was performed to investigate the optimum abrasive and friction milling ratio. This was accomplished by determining changes in the quality, such as whiteness, moisture content, broken kernel, unstripped embryo rate, and surface characteristics or milling difference, during an abrasive and friction based milling process. When only abrasive was milled, the increase of whiteness was fast in the first milling, whereas the increasing rate of whiteness was small in the latter milling. The decreasing rate of moisture content and broken kernel increased as the friction milling ratio was increased. Combining with the friction milling was considered a suitable method because the unstripped embryo rate was high only when abrasive milling was used. In the case of a high abrasive milling ratio, a significant milling difference was observed in the initial milling. This indicated that the milling difference was not completely eliminated despite using friction milling in the latter milling. Consequently, it was necessary to minimize the milling difference in the initial milling. When milling quality was synthetically considered, the abrasive milling ratio was varied from 20~50%. When the abrasive milling ratio was greater than 40%, the external quality of the rice milled deteriorated since holes and defects generated on the surface in the initial milling were not removed. Due to this deterioration in surface characteristics, an abrasive milling ratio of 30% was identified as a suitable level.

• Proceedings of the Korea Technology Innovation Society Conference
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• 한국기술혁신학회 2003년도 춘계학술대회
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• pp.413-425
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• 2003

Information Technology is the kernel technology deciding the industrial standard of one nation, and biotechnology will be the main technology of next generation. Based on this fact, a lot of efforts were made to industrialize them. Nano Technology is beginning to position itself as the kernel fusion technology, and its usage and popularity is expanding. Environmental and Energy Technology is a must-have strategic technology considering the increase demand of new energy development, the international environment correspondence, the environment-friendly production, and so forth. Space Technology is the field, which will contribute to raise the domestic component and system technology to the next level. In 2001, new technology research development costs total of 1 trillion 32 billion won in the following fields; 437.82 billion won in IT, 88.457 billion won in BT, 46.799 billion won in NT, 315.682 billion won in ET, and 112 billion won in ST. from component ratio, IT forms 42% which is the most, 31% for ET and in order of BT, ST and NT. ETRI and KISTI are concentrating on IT, KIBB is on BT, KAERI, KIER, KERI and KBSI are focusing on ET, and KIMM, KRISS, KRICT and KORDI is participating together in 4∼5 new technology such as IT, BT, NT and ET. Funds for research development costs in 5 new technology fields of 13 contribution (year) are consisted as follows; The Office for Government Policy Coordination has contributed 131 billion won (13%), 387 billion won (37%) by MOST, 256 billion won (25%) by Ministry of Information and Communication, 67 billion won (6%) by Ministry of Commerce, Industry and Energy, 19% by others and the industrial world. < Strategy for Technology Advancing > o Promotion of comprehensive contributing (year) new technology development research plan project o Increase research efficiency by promoting new technology development project connected with peculiar projects of organization by contribution (year) o Formation of superior research group by technology and introduction of operation system for research accumulation are needed. o Technology demand-oriented assignment deduction and promotion of research development project connected with intermediate long term objective o National will and investment extension of research development costs, training and popularization of professionals, commercialization promotion with efficient control for research plan and result.

• Journal of KIISE
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• 제42권12호
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• pp.1486-1494
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• 2015

While Linux-based mobile devices such as smartphones are increasingly used, they often exhibit poor response time. One of the factors that influence the user-perceived interactivity is the high page fault rate of interactive tasks. Pages owned by interactive tasks can be removed from the main memory due to the memory contention between interactive and background tasks. Since this increases the page fault rate of the interactive tasks, their executions tend to suffer from increased delays. This paper proposes a framework-assisted selective page protection mechanism for improving interactivity of Linux-based mobile devices. The framework-assisted selective page protection enables the run-time system to identify interactive tasks at the framework level and to deliver their IDs to the kernel. As a result, the kernel can maintain the pages owned by the identified interactive tasks and avoid the occurrences of page faults. The experimental results demonstrate the selective page protection technique reduces response time up to 11% by reducing the page fault rate by 37%.

• Journal of the Korean Association of Geographic Information Studies
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• 제20권2호
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• pp.89-101
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• 2017

The study used GIS methods to analyze a business district consisting of traditional markets and large-scale stores, to determine the level of support needed for small enterprises in an urban area of Changwon-si, Gyeongsangnam-do. Data gathered on the area was analyzed using GIS tools such as Kernel density, Network analysis, and Huff modeling. Traditional markets are concentrated in areas where large-scale stores are located, and data analyses show that the number of consumer'use of large-scale stores (157,071) was three times that of traditional markets (59,953). One explanation for these results is that the large-scale stores are located either in densely populated areas or are adjacent to the traditional markets. Therefore, standards and regulations are needed to support small enterprise business districts. In the future, the results of this study can be used as a reference for planning and supporting traditional market business districts.