• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3100-3106
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• 2014

This paper develops power measurement system with multiple sensor input channels (voltage-8 channels and current-10 channels) that simultaneously can monitor power components for both supply and load side of power system. The hardware implementation of the proposed system is based on TMS320C42 DSP and signal processing program algorithm to calculate power components use the definition of IEEE Standard 1459-2010 related power quality. The performance of the developed system is tested by using standard ac power source device, and the test results showed that accuracy of the developed system is less than 0.2 %. Also, field test of the proposed system in the three-phase and four-wire power system was implemented. Simultaneous multiple channel measurement and analysis of power components in commercial and industrial electrical power system using the proposed system will be necessary to reduce power quality problems.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.9
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• pp.465-474
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• 2005

For high density SoC design, on-chip communication based on bus interconnection encounters bandwidth limitation while an NoC(Network-on-Chip) approach suffers from unacceptable complexity in its Implementation. This paper introduces a new on-chip communication protocol, SNP (SoC Network Protocol) to overcome these problems. In SNP, conventional on-chip bus signals are categorized into three groups, control, address, and data and only one set of wires is used to transmit all three groups of signals, resulting in the dramatic decrease of the number of wires. SNP efficiently supports master-master communication as well as master-slave communication with symmetric channels. A sequencing rule of signal groups is defined as a part of SNP specification and a phase-restoration feature is proposed to avoid redundant signals transmitted repeatedly over back-to-back transactions. Simulation results show that SNP provides about the same bandwidth with only $54\%$ of wires when compared with AMBA AHB.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.855-864
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• 2004

Programmers can be got the test-related information for implementation without interference of source code complexity by use of the formal specification. Especially the external inputs and system responses can be represented precisely by formal specification in testing phase of web-based software systems. This paper suggests a method of extracting test cases by use of formal specification. Object-Z formal specification represents various test-related information for complex functions of web-based applications. State Transition Models could be built from the formal specification so that test scenarios were extracted from STDs from the highest level to detail levels. The target system for verification of this method is a web-based banking system which is necessary to be secured and critical on errors. This method would be an important factor in automatizing test procedure for web-based application software systems combining the user-base test technique.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.223-228
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• 2007

The Digital Frequency Synthesizer(DFS) that generates the wideband signal with high speed frequency hopping rate and high frequency resolution characteristics was designed and implemented in this paper The DFS was applied as local oscillator for direct frequency conversion IF modules of DVB-RCS, which directly generates the transmission immediate frequency signal by using DDS and wideband PLL technologies. The DDS technology provides high speed frequency hopping rate and high frequency resolution characteristics, which are also the DVB-RCS requirement. The wideband PLL technology also provides the wideband signal generation, which is a necessity for direct frequency conversion modules. The implemented DFS provides the spurious suppression characteristic of -50 dBc and less, frequency resolution of 0.233 Hz and frequency hopping rate of 125 ns, respectively. Also the DFS represents the amplitude flatness of 3 dB and less in the pass-band, and phase noise characteristic of -75 dBc/Hz at 1 kHz frequency offset.

• Journal of Climate Change Research
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• v.5 no.4
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• pp.331-338
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• 2014

The continued efforts to reduce GHG emission by international cooperation and each country are in progress. As part of these efforts, Korea's ETS is enforced in 2015. This was the time to make strategies for each company to respond Korea's ETS. This study was performed to suggest a draft of basic strategies for electronic component industry in current Korea's ETS stage are as follows; - Analyzing the nature of electronic component industry - Identifying needs for corresponding ETS of electronic component industry - Analyzing basic countermeasures for each stage of ETS - Suggesting drafts of basic strategies for electronic component industry in current Korea's ETS stage The result of this study, the current stage of Korea's ETS is moving from implementation of the scheme become determined and prepare the minimum corresponding to direct corresponding to the regulation and market change. Electronic component industry has many GHG emission growth(or change) factor, and it will be make electronic component industry as a buyer when Korea's ETS is enforced. Korea's ETS will be clearly act as a regulation rather than new business for electronic component industry. Therefore, identifying the Korea's ETS as a regulation is resonable strategy for corresponding the scheme. The basic strategies of electronic component industry th responding Korea's ETS are as follows; - Building internal organization and decision-making system before enforcement the Korea's ETS - Establishing internal basic corresponding strategies according to carbon price forecast scenarios - Considering the energy consumption and GHG emissions in design phase and preparing the global ETS market in mid or long term.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1687-1695
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• 2021

In this paper, it is designed and analyzed the beamforming antenna using the butler matrix. The operating frequency of the proposed beamforing antenna is ISM band of 2.4 GHz band and the component of the beamforing antenna consisted of a 1×4 array antenna and a 4×4 butler matrix. Each output port of 4×4 butler matrix outputs the signal having a different phase, it is provided to each input port of 1×4 array antenna. The beamforming antenna with four output ports forms a total of four beams. In order to analyze the radiation pattern of the beamforming antenna, it was provided by switching the signal to the input port and proceeded the Individual analysis for the input port 1 to 4. The main beams of the proposed beamforming antenna were formed in the -12°, 40°, -40° and 12° directions according to each input port, respectively.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1022-1035
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• 2021

This study estimated the effect of exposure to propiconazole through implementation and residues in finishing pigs. We analyzed the expression of fibrosis-related genes and performed histological analysis of the blood, liver, kidney, muscle, ileum, and fat tissues. The animals were exposed for 28 d to different concentrations of propiconazole (0.09, 0.44, 0.88, 4.41, and 8.82 mg/kg bw/d). Quantitative, gene expression, and histological analyses in tissues were performed using liquid chromatography mass spectrometry, real-time PCR, and Masson's trichrome staining, respectively. Final body weight did not differ among groups. However, genes involved in fibrosis were significantly differentially regulated in response to propiconazole concentrations. Glucose, alanine aminotransferase, and total bilirubin levels were significantly increased compared with those in the control group, while alkaline phosphatase level was decreased (p<0.05) after exposure to propiconazole. The residue limits of propiconazole were increased in the finishing phase at 4.41 and 8.82 mg/kg bw/d. The liver, kidney, and ileum showed blue staining after propiconazole treatment, confirmed by Masson's trichrome staining. In conclusion, these findings suggest that propiconazole exposure disturbs the expression of fibrosis-related genes. This study on dietary propiconazole in pigs can provide a basis for determining maximum residue limits and a better understanding of metabolism in pigs and meat products.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.6
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• pp.490-496
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• 2018

The consistency of the initially designed waves in the domain is essential for accurate calculation of the added resistance in waves through CFD. In particular, unwanted reflected waves at domain boundaries can cause incorrect numerical solutions due to the superposition with initially designed waves. Euler Overlay Method(EOM) is one of the methods for reducing wave reflections by adding an additional source term to momentum and phase conservation equations, respectively. In this study, we apply the Euler Overlay Method(EOM) to the open-source CFD library, OpenFOAM(R), to simulate the accurate free-surface waves in the domain and the parametric study is performed for efficient implementation of Euler Overlay Method(EOM). Considering that the damping efficiency depends on the selection of the overlay parameter in the added source terms, the size of overlay zone and the wave steepness, the influences of these factors are tested through the wave elevation measured at constant time intervals in the 2D numerical wave tank. Through this process, guidelines for selection of optimal overlay parameter and overlay zone size that can be applied according to the scaling law are finally presented.

• Coupled systems mechanics
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• v.7 no.6
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• pp.649-668
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• 2018

In this paper, we present a numerical model for fluid-structure interaction between structure built of porous media and acoustic fluid, which provides both pore pressure inside porous media and hydrodynamic pressures and hydrodynamic forces exerted on the upstream face of the structure in an unified manner and simplifies fluid-structure interaction problems. The first original feature of the proposed model concerns the structure built of saturated porous medium whose response is obtained with coupled discrete beam lattice model, which is based on Voronoi cell representation with cohesive links as linear elastic Timoshenko beam finite elements. The motion of the pore fluid is governed by Darcy's law, and the coupling between the solid phase and the pore fluid is introduced in the model through Biot's porous media theory. The pore pressure field is discretized with CST (Constant Strain Triangle) finite elements, which coincide with Delaunay triangles. By exploiting Hammer quadrature rule for numerical integration on CST elements, and duality property between Voronoi diagram and Delaunay triangulation, the numerical implementation of the coupling results with an additional pore pressure degree of freedom placed at each node of a Timoshenko beam finite element. The second original point of the model concerns the motion of the outside fluid which is modeled with mixed displacement/pressure based formulation. The chosen finite element representations of the structure response and the outside fluid motion ensures for the structure and fluid finite elements to be connected directly at the common nodes at the fluid-structure interface, because they share both the displacement and the pressure degrees of freedom. Numerical simulations presented in this paper show an excellent agreement between the numerically obtained results and the analytical solutions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.66-69
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• 2016

In this paper, we suggests a Ka-band LNB considering next-generation UHD satellite TVRO. Since Ka-band has grater attenuation than Ku-band in atmosphere, we designed the low-noise down-converter to improve receiving sensitivity and to extend a dynamic range of receiver. It aims to compensate a quality of ultra high definition transmission signal for rainfall. The low-noise block diagram consists of a three-staged amplifier (LNA), band-pass filter for deleting image (BPF), mixer and IF when considering nonlinear characteristics in the receiver RF front end module. Also, we showed a LNB through optimization processes affecting dynamic range directly in receiver FEM. Asa resuly of experiment, the gain of low-noise down-converter show between 58.5dB and 60.7dB, the noise figure has a high characteristic as 1.38dB. Finally, the phase noise of local oscillator is -63.10dBc at 100MHz offset frequency.