• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.23-29
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• 2004

In this paper, the asynchronous quasi dual-port SRAM employing a single port structure in SRAM embedded SOC (System On Chip) is proposed. External host can access the internal SRAM freely and the data on internal SRAM can be transferred to an another external circuitry without a synchronous signal of an external host, which operates as an asynchronous dual-port SRRAH The performances of the proposed circuits and control structure are verified through the simulation and we fabricated it using a 0.35um CMOS technology. As the results, the chip shows reduced area about 20% and saved power also 20% than conventional architectures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5843-5849
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• 2015

This study analyzes the factor demand structure of sweet persimmon as a part of finding out cost cutting measures. Income and cost data from 2001~2013 Agricultural Income Survey are used for placing the translog cost function and estimating price elasticies and cross elasticities of labor, capital and intermediate input. The result shows that own price elasticities of all factors are small in absolute terms. Additionally the result indicates capital and intermediate input cannot be a substitution for labor, which is a top-line cost-share. It means that the demand for labor cconstitutionally can't be reduced in a short time. This implies that cost reduction should be done focusing on intermediate input, particularly on fertilizer and materials which have higher price elasticity of demand.

• Wind and Structures
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• v.36 no.2
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• pp.133-147
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• 2023

The random vibration of saddle membrane structures under wind load is studied theoretically and experimentally. First, the nonlinear random vibration differential equations of saddle membrane structures under wind loads are established based on von Karman's large deflection theory, thin shell theory and potential flow theory. The probabilistic density function (PDF) and its corresponding statistical parameters of the displacement response of membrane structure are obtained by using the diffusion process theory and the Fokker Planck Kolmogorov equation method (FPK) to solve the equation. Furthermore, a wind tunnel test is carried out to obtain the displacement time history data of the test model under wind load, and the statistical characteristics of the displacement time history of the prototype model are obtained by similarity theory and probability statistics method. Finally, the rationality of the theoretical model is verified by comparing the experimental model with the theoretical model. The results show that the theoretical model agrees with the experimental model, and the random vibration response can be effectively reduced by increasing the initial pretension force and the rise-span ratio within a certain range. The research methods can provide a theoretical reference for the random vibration of the membrane structure, and also be the foundation of structural reliability of membrane structure based on wind-induced response.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.353-356
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• 2002

In this paper, we design an efficient, scalable one-dimensional discrete wavelet transform (1DDWT) filter using data reorder unit (DRU). At each level, the required hardware is optimized by sharing multipliers and adders because the input rate is reduced by a factor of two at each level due to decimation. The proposed architecture shows 100% hardware utilization by balancing hardware with input rate. Furthermore, sharing the coefficients of the highpass and the lowpass filters using the mirror filter property reduces the number of multipliers and adders by half. We designed a scalable DRU that efficiently reorders and feeds inputs to highpass and lowpass filters. The proposed DRU-based architecture is so regular and scalable that it can be easily extended to an arbitrary 1D DWT structure with M taps and J levels. Compared to other architectures, the proposed DWT filter shows efficiency in performance with relatively less hardware.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.1
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• pp.35-41
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• 2002

XML(eXtensible Markup Language) based electronic catalog is very useful for searching target information because of its structural and contents based searching support capability. And XML document editing is easier than HTML because of XML document is divided by structure, contents and presentation. This paper is to present a prototype of XML based Electronic Catalog Management System(ECMS) whose system consists of data input, output and manipulation system for inserting, updating, editing and deletion. A proposed system could resolved the problems at virtual intermediary shopping mall invloved in the difficulty of interoperability when customer try to compare similar products at mixed shopping mall and reduced web service costs at independent shopping mall by using XML format. The proposed ECMS offers rapid response capability for product data change of electronic catalog and easy and friendly interoperability among similar products.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.148-153
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• 1998

In order to control thermal deformation of machine origin of machine tools due to internal and external heat sources, the real-time compensation system has been developed. First, GMDH models were constructed to estimate thermal deformation of machine origin for a vertical machining center through the measurement of deformation data and temperature data of specific points on the machine tool. Thermocouples and gap sensors are used respectively for measurement. These models are nonlinear equations with high-order polynomials and implemented in a multilayered perceptron type network structure. Secondly, work origin shift method were developed by implementing digital I/O interface board between CNC controller and IBM-PC. The work origin shift method is to shift the work origin by the compensation amounts which is calculated by pre-established GMDH model. From the experimental result, thermal deformation of machine origin was reduced to below $\pm$5${\mu}{\textrm}{m}$.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.129-132
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• 1990

This paper reports an expert system for coordination of protective relays in the high voltage transmission system. The proposed system consists of five modules and has adopted the frame and production rule representations achieving the efficient data storage and knowledgebases. It has an interface to the fault program PSS/E and has reduced the data retrival time by implementing the local database containg only the minimum information for the process. Different relay parameters and output formats of the setting results can be easily incorporated owing to the rule-based structure. Graphics-based output helps understanding of the process and enhances the practical power.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.365-370
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• 2002

In this paper external image multi-processing digital signal the transmit is the possibility of doing system with the PCI the design. The bottle-neck which it follows in transmission ratio limit of the CPU and the circumference machineries and tools against the image data which with the improve one thing becomes the processing with the real-time efficiently the transmit and the control is the possibility of doing structure the proposed. The also with the resource amount used 13% reduced which PCI fast data transfer and DMA function. The designed is operation verification against the function and the timing which use Max+plus II.

• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1559-1562
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• 2009

The influence of hot pressing on the pore structures of Nafion membranes was investigated by observing the Nafion before and after hot pressing with $^1H$ nuclear magnetic resonance (NMR) spectroscopy. The freezing point depression and chemical shift data of water in the Nafion indicated the presence of two different pore size ranges in Nafion. Hot pressing mainly reduced the sizes and number of the big pores. The reduction of water uptake and proton conductivity after hot pressing was explained by this variation of pore size and number. We demonstrated the potential application of chemical shift data and NMR cryoporometry experiments to measure the relative pore sizes, on a nano scale, and numbers.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.04a
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• pp.31-36
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• 1990

The probabilistic characteristics of wind loads have been analyzed using statistical data on wind speeds, pressure coefficient, exposure coefficient, and gust factor. The wind speed data collected in 25 nationwide weather stations have been modified to be consistent in measuring height, exposure condition as well as averaging time, Having performed Monte Carlo simulation for various heights and site conditions, the statistical models of wind loads were determined, in which Type-I extreme value distribution has been applied. The models also incorporate a reduction factor of 0.85 to account for the reduced probability that the maximum wind speed will occur in a direction most unfavorable to the response of structure.