• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.2
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• pp.247-268
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• 2011

Due to the application-specific nature of wireless sensor networks, the sensitivity to such a requirement as data reporting interval varies according to the type of application. Such considerations require an application-specific, parameter tuning paradigm allowing us to maximize energy conservation prolonging the operational network lifetime. In this paper, we propose a reporting interval adaptive, sensor control platform for energy-saving data gathering in wireless sensor networks. The ultimate goal is to extend the network lifetime by providing sensors with high adaptability to application-dependent or time-varying, reporting interval requirements. The proposed sensor control platform is based upon a two phase clustering (TPC) scheme which constructs two types of links within each cluster - namely, direct link and relay link. The direct links are used for control and time-critical, sensed data forwarding while the relay links are used only for multi-hop data reporting. Sensors opportunistically use the energy-saving relay link depending on the user reporting, interval constraint. We present factors that should be considered in deciding the total number of relay links and how sensors are scheduled for sensed data forwarding within a cluster for a given reporting interval and link quality. Simulation and implementation studies demonstrate that the proposed sensor control platform can help individual sensors save a significant amount of energy in reporting data, particularly in dense sensor networks. Such saving can be realized by the adaptability of the sensor to the reporting interval requirements.

• Journal of Biomedical Engineering Research
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• v.27 no.1
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• pp.30-37
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• 2006

Injecting currents into an electrically conducting subject, we may measure the induced magnetic flux density distributions using an MRI scanner. The measured data are utilized to reconstruct cross-sectional images of internal conductivity and current density distributions in Magnetic Resonance Electrical Impedance Tomography (MREIT). Injection currents are usually provided in a form of mono-polar or bi-polar pulses synchronized with an MR pulse sequence. Given an MRI scanner performing the MR phase imaging to extract the induced magnetic flux density data, the current source becomes one of the key parts determining the signal-to-noise ratio (SNR) of the measured data. Since this SNR is crucial in determining the quality of reconstructed MREIT images, special care must be given in the design and implementation of the current source. This paper describes a current source design for MREIT with features including interleaved current injection, arbitrary current waveform, electrode switching to discharge any stored charge from previous current injections, optical isolation from an MR spectrometer and PC, precise current injection timing control synchronized with any MR pulse sequence, and versatile PC control program. The performance of the current source was verified using a 3T MRI scanner and saline phantoms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2369-2378
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• 2009

In this paper, we implement measurement functionality for performance measurement of the GSM (Global System for Mobile Communication) terminal by using software. Generally speaking, the receiving algorithms in normal modems cannot be used directly to the measurement system due to the lack of the algorithm accuracy. In this paper, we propose the new receiver algorithm for precise GSM signal measurements. In the receiving algorithm, 2-stage (coarse stage, fine stage) parameters estimation (symbol-timing, frequency offset, carrier phase) scheme is used. To improve the estimation accuracy, we increase the number of the received signal samples by interpolation. The proposed GSM signal measurement algorithm can be used for verifying the hardware measurement system. In addition, the proposed algorithm can be used for the commercial system through code execution speed optimization.

• 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.