• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.262-269
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• 2004

Ship structures are basically an assembly of plate elements and the load-carrying capacity or the ultimate strength is one of the most important criteria for safety assessment and economic design. Also, Structural elements making up ship plated structures do not work separately, resulting in high degree of redundancy and complexity, in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy needed and the degree of complexity of the analysis to be used. On this study, to investigate effect of analysis range, the finite element method are used and their results are compared varying the analysis ranges. The model has been selected from bottom panels of large merchant ship structures. For FEA, three types of structural modeling are adopted in terms of the extent of the analysis. The purpose of the present study is to numerically calculate the characteristics of ultimate strength behavior according to the analysis ranges of stiffened panels subject to uniaxial compressive loads.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.655-658
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• 2016

Xilinx 7-Series FPGA(Field Programmable Gate Array)s mainly used for the implementation of high-performance digital circuit have SRAM-type configuration memory and can malfunction when soft errors occur in their configuration memory. SEM(Soft Error Mitigation Controller) offered by Xilinx helps users mitigate the influence of soft errors in configuration memory. When soft errors occur, SEM Controller can recover the state of FPGA through partial reconfiguration if the soft errors are correctable by ECC(Error Correction Code) and CRC(Cyclic Redundancy Code). This paper presents the availability analysis of Xilinx 7-Series FPGAs against soft errors under the protection of the SEM Controller. Availability functions are derived and compared according to the correction capability of the SEM Controller. The result may help to estimate the reliability of SRAM-based FPGA running in an environment where soft errors may occur.

• Journal of Ecology and Environment
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• v.45 no.1
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• pp.17-23
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• 2021

Background: Montane wetlands are unique wetland ecosystems with distinct physicochemical characteristics, and Molinia japonica often makes dominant communities in montane wetlands in South Korea. In order to figure out the environmental characteristics of M. japonica habitats and the major factors for the growth of M. japonica, field surveys were conducted in five wetlands from September to October 2019. Also, soil was collected at every quadrats installed in surveyed wetlands to analyze the physicochemical features. Results: The relative coverage of M. japonica was higher in low latitude wetlands than in high latitude. Redundancy analysis showed that soil water content had the strongest effect on the growth of M. japonica (F = 23.0, p < 0.001). Soil water content, loss on ignition, and relative light intensity showed a high correlation with the density (R = 0.568, 0.550, 0.547, respectively, p < 0.01) and the coverage of M. japonica (R = 0.495, 0.385, 0.514, respectively, p < 0.01). Soil water content, loss on ignition, and pH were highly correlated with each other. Conclusions: Molinia japonica lives in acidic wetlands at high altitude in temperate zone of low latitude, with peat layer placed on the floor. Also, M. japonica prefers open spaces to secure enough light for photosynthesis. High shoot production of M. japonica resulted in adding new peat material in every year, and this layer enforces the environmental characteristics of M. japonica habitats. This study may provide insights for further understanding of the method how wetlands maintain acidic condition by itself in montane wetlands in temperate zone.

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.346-350
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• 2009

Although salt is known to influence the performance of nitrification significantly, it has not been well reported on how salt affects ammonia-oxidizing bacterial(AOB) community compositions and dynamics in wastewater treatment bioreactors. In this study, these questions were evaluated in a full-scale bioreactor treating saline wastewater. Clone library analysis for the ammonia monooxygenase subunit A gene revealed that AOB belonging to the Nitrosomonas europaea and the N. oligotropha lineages inhabited in the bioreactor. Terminal restriction fragment length polymorphism analysis for monthly samples demonstrated a fluctuation pattern among AOB populations, although AOB within the N. europaea lineage were dominant during the test period. Correlation analysis between patterns of terminal restriction fragments and environmental variables suggested that sodium, chloride, and sulfate were less important; rather, temperature was the most significant factor affecting the AOB community in the bioreactor.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.100-108
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• 2004

In this paper, the new casing oscillator, which is a construction machine and which structure is similar to that of a parallel manipulator with redundancy, is proposed. The singularity analysis of this machine is performed by two different methods. First, the singularities are found by the numerical method at configurations where the rank of the Jacobian matrix becomes deficient. The singularities are outside the workspace. To investigate the physical information on these configurations, the singularities are examined by the geometric method at configurations where the casing oscillator cannot resist the external forces and moments applied to the upper platform due to losing static equilibrium. The results of the geometric method are the same as those of the numerical method. It proves that the new casing oscillator is free from the singularity, which causes serious problems to a parallel manipulator.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.725-731
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• 2006

Hot Standby sparing system detecting faults by using software, and being tolerant any faults by using Hardware Redundancy is difficult to perform quantitative reliability prediction and to detect real time faults. Therefore, this paper designs Hot Standby sparing system using hardware basis self checking logic in order to overcome this problem. It also performs failure mode analysis of Hot Standby sparing system with designed self checking logic by using FMEA (Failure Mode Effect Analysis), and identifies reliability assessment of the controller designed by quantifying the numbers of failure development by using FTA (Fault Tree Analysis)

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.10a
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• pp.193-200
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• 1997

Current seismic design code is based of the assumption that the designed structures would be behaved inelastically during a severe earthquake ground motion. For this reason, seismic design forces calculated by seismic codes are much lower than the forces generated by design earthquakes which makes structures responding elastically. Present procedures for calculating seismic design forces are based on the use of elastic spectra reduced by a strength reduction factors known as "response modificaion factor". Because these factors were determined empirically, it is difficult to know how much inelastic behaviors of the structures exhibit. In this study, base shear forces required to maintain target ductility ratio were first calculated from nonlinear dynamic analysis on the single degree of freedom system. And then, base shear foeces specified in seismic design code compare with above results. If the strength(base shear) required strength should be filled by overstrength and/or redundancy. Therefore, overstrength of moment resisting frame structure will be estimated from the results of static nonlinear analysis(push-over analysis).analysis).

• Korean Institute of Interior Design Journal
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• no.8
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• pp.32-38
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• 1996

The main focus of this paper is to apply contemporary aesthetics and psychological study with interior design analysis. Up to now, the methodology of interior design analysis has been developed toward a more qualitative way. By the virtue of the perception , congnition , and information theory, which oriented toward a quantitative approach, it became possible to investigate interior space analysis to a more objective and scientific ways. The purpose of this study is to investigate Modern and Post-Modern interior - architectural style with quantitative analytical method. The subjective interior critique studied by intuitive research will be transferred to scientific way by using quantitative formula . Savoye Villa and Guardiola House were selected as study model, because each architectural works ware regarded as masterpieces of Modern and Post-Modern style. These two oppositional style model will be distinguished with mathematical quantity by calculating Iave , Hmax, and Redundancy formula.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.251-260
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• 2000

Seismic performance evaluation systems require rational classification of structure systems, proper evaluation criteria, and their scoring index for synthesis. Current seismic performance systems need expert judgments based on collection of available data, approximate analysis of important items, and various scoring system. This study presents a three-step seismic performance evaluation system for building structures in Korea. Each evaluation step determines the seismic performance and the method depends on the degree of refinement of analysis. The preliminary step evaluation involves the global attributes of structures such as vertical irregularity, asymmetric plan, redundancy, and age of structures. The second step requires an elastic analysis for estimation of forces acting on critical sections and checks the strength and ductility. The final step requires inelastic capacity of structures. Each stephas own evaluation scheme with proper weighing factor dependent on the importance and consequence. This study applies the fuzzy theory to a scoring method that synthesizes the individual quantity to a representative value.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.10
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• pp.2411-2429
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• 2013

In this paper, we extend the case of information exchange error mitigation for the distributed orthogonal space-time block code (DOSTBC) for two transmit antennas to distributed quasi-orthogonal space-time block code (DQOSTBC) for four transmit antennas. A rate 1 full-diversity DQOSTBC for four transmit antennas is designed. The code matrix changes according to different information exchange error cases, so full diversity is maintained even if not all information exchange is correct. We also perform analysis of the pairwise error probability. The performance analysis indicates that the proposed rate 1 DQOSTBC outperforms rate 1/2 DOSTBC for four transmit antennas at the same transmission rate, which is confirmed by the simulation results.