• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.149-155
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• 1997

This study was carried out to investigate the effects of phenobarbital sodium(PB) and 3-methylcholanthrene(3-MC) on carbofuran cytotoxicity and to develop antitoxic agents based on the effectivness. Experimental groups for carbofuran cytotoxicity were divided into five groups ; medium alone and four treatments of carbofuran (1, 25, 50 and $100{\mu}M)$, and those for compensation effects were divided into six groups ; medium alone, $IC_{50}$ carbofuran and four combinations of carbofuran and PB or 3-MC($IC_{50}$ carbofuran plus 1, 25, 50, $100{\mu}M$ of PB and 3-MC, respectively). After incubation for 48 hrs under the same conditions, MTT(Tetrazolium MTT), NR(Neutral red) and SRB(Sulforhodamine B protein) assay were performed. Fifty percentage inhibition of MTT, NR, and SRB against carbofuran in rat fibroblast cell were 60.7, 82.5 and $87.0{\mu}M$, respectively. At the combination treatments of $IC_{50}$ of carbofuran and $100{\mu}M$ of PB, the significant compensation effects were observed from the results of MTT and NR but not from that of SRB absorbance. And at the combination treatments of $IC_{50}$ of carbofuran and 3-MC, the relatively significant compensation effects were found at $50{\mu}M$ 3-MC from the results of MTT and at $100{\mu}M$ 3-MC from that of NR and SRB absorbances, respectively. From the results of light microscopy, combination treatments of $carbofuran(IC_{50})$ and PB or 3-MC showed good regeneration in carbofuran toxicity of rat fibroblast cells. These results suggest that PB or 3-MC can compensate the cytotoxity of carbofuran insecticide in rat NIH3T3 fibroblast cells.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.239-245
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• 2016

In this study, a 12 V PWM boost converter was designed with the optimal values of the external components of the power stage was well as the compensation stage for smart electronic applications powered by a battery device. The 12 V boost PWM converter consisted of several passive elements, such as a resistor, inductor and capacitor with a diode, power MOS switch and control IC chip for the control PWM signal. The devices of the power stage and compensation stage were designed to maintain stable operation under a range of load conditions as well as achieving the highest power efficiency. The results of this study were first verified by a simulation in SPICE from calculations of the values of major external elements comprising the converter. The design was also implemented on the prototype PCBboard using commercial IC LM3481 from Texas Instruments, which has a nominal output voltage of 12 V. The output voltage, ripple voltage, and load regulation with the line regulation were measured using a digital oscilloscope, DMM tester, and DC power supply. By configuring the converter under the same conditions as in the circuit simulation, the experimental results matched the simulation results.

• Journal of the HCI Society of Korea
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• v.12 no.4
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• pp.65-73
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• 2017

While electricity demand is generally increasing, stably controlling supply is becoming a serious challenge because renewable energies are becoming popular and often their productions are dependent on the weather. The 'demand response' programs can be used to complement the problems of renewable energies, and therefore their role is becoming increasingly important. This study provides an analysis of a demand response pilot that was conducted in Korea. The study first focused on questionnaire surveys and in-depth interviews, and the data was used to perform a Technology Acceptance Model (TAM) analysis. The goal of the pilot was to have the residential users reduce their power consumptions when an energy reduction mission is issued during peak load hours. The experimental subjects consisted of two groups with different characteristics. Subjects in group A obtained smart meters as an optional function of IoT platform service provided by a mobile service company, and received a charge deduction as their compensation. Subjects in group B either voluntarily purchased smart meters as individuals or received them by participating in an energy self-sufficient village program that was run by a local government, and were entitled to a donation as their compensation. With the analysis, group A was found to fit the extended technology acceptance model that includes perceived playfulness in addition to perceived ease of use and perceived usefulness. On the contrary, group B failed to fit the model well, but perceived usefulness was found to be relatively more important compared to group A. The results indicate that the residential energy groups' behavior changes are dependent on each group's characteristics, and group-specific DR design should be considered to improve the effectiveness of DR.

• Journal of Broadcast Engineering
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• v.15 no.6
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• pp.768-782
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• 2010

Because of the different shooting position between multi-view cameras and the imperfect camera calibration, Illumination mismatches of multi-view video can happen. This variation can bring about the performance decrease of multi-view video coding(MVC) algorithm. A histogram matching algorithm can be applied to recompensate these inconsistencies in a prefiltering step. Once all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching, the coding efficiency of MVC is improved. However the histogram distribution can be different not only between neighboring views but also between sequential views on account of movements of camera angle and some objects, especially human. Therefore the histogram matching algorithm which references all frames in chose view is not appropriate for compensating the illumination differences of these sequence. Thus we propose new algorithms both the image classification algorithm which is applied two criteria to improve the correlation between inter-view frames and the histogram matching which references and matches with a group of pictures(GOP) as a unit to advance the correlation between successive frames. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with the conventional algorithms.

• Management & Information Systems Review
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• v.23
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• pp.75-97
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• 2007

In the meantime hospital system of Korea has institutionally performed its errand in stable circumstance, however the system now faces with new environment of change of customer's satisfaction, of regime, deepening of competition, and opening market. Under the rapidly and complicatedly changing circumstance, the hospital system is required to promote getting a dominant position in the competition, enhancing outcome, creating value added, and customer satisfaction in both internally and externally likewise other organizations, as they continuously introduce a knowledge management and originate, accumulate, and put the knowledge to practical use. This organization capacity of knowledge management involves a process of management that requires great change of all organizations and individuals and it is brought up through four steps which are Initiation, Propagation, Integration, and Networking. The main factors of successful knowledge management are intension of the chief executive officer(CEO), organizational culture, appraisal and compensation of work, knowledge controlling system, and organizational structure, and each of these five stage has got different characteristic. To be successful by introducing knowledge management, hospital organization should be based on these premises. Not only CEO or the director of a hospital, but also the constituent members should be fully aware of knowledge, the characteristic of knowledge management, and successful factors of this operation. Should understand step-by-step characteristic of knowledge management, therefore able to analyse a situation of specific hospital and see which step corresponds to that hospital. By analysing, constituents should make up for the weak points and ready to move on to next step. CEO or the director of a hospital should be aware of knowledge management as a strategic factor which is able to get a dominant position in the rapidly changing environment, and also it should be firm in the director's intention to introduce the knowledge management into the hospital. By continuously carrying out education and training constituent members, the director of a hospital should promote their interest and participation in knowledge management, and build an organization culture that ultimately creates, accumulates, shares, and put the knowledge to practical use. The hospital organization needs to systematize an institution of objective compensation that corresponds to objective appraisal of knowledge management outcome. The hospital ought to build knowledge controlling system in stages, in order to take the initiative in rapidly changing environment. By considering the characteristic of hospital system, it is required to change the organizational structure into self-managing team which is a sort of horizontal structure that allows members to make decisions and take the responsibility by themselves. The limitation of this study is experimental study. Positive investigation about successful factors of hospital knowledge management and characteristic of each steps is expected with following study.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.9
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• pp.854-864
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• 2016

The use of small drone platform has become a popular topic in these days but its application for SAR operation has been little known due to the burden of the payload implementation. Drone platforms are distinguished from the conventional UAV system by the increased vulnerability to the turbulences, control-errors and poor motion stability. Consequently, sophisticated motion compensation may be required to guarantee the successful acquisition of high quality SAR imagery. Extremely limited power and mass budgets may prevent the use of additional hardwares for motion compensation and the difficulty of SAR focusing is further aggravated. In this paper, we have carried out a feasibility study of mico-SAR drone operation. We present the image acquisition results from the preliminary flight tests and a quality assessment is followed on the experimental SAR images. The in-flight motion errors derived from the unique drone movements are investigated and attempts have been made to compensate for the geometrical and phase errors caused by motions against the nominal trajectory. Finally, the successful operation of drone SAR system is validated through the focussed SAR images taken over test sites.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.4
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• pp.176-182
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• 2014

This paper introduces the development of global fringe search (GFS) software for preprocessing of Daejeon Correlator. In case of the VLBI observation, a observer conducts the observation for the reference sources with strong and point-like radio stars on schedule in order to confirm the well-observedness of the radio source by the radio telescope. The correlator performs the correlation for the reference sources to detect the fringe completely. We developed the GFS software by calculating the precise delay time between each observatory based on specific observatory. Then, this software calculates the precise delay time by using the delay model (correlator model) of reference source and information of time offset between the Hydrogen Maser frequency standard and GPS (Global Positioning System) clock located in each observatory through the correlation preprocessing. In order to confirm the performance of the developed software, experiments were carried out for the reference sources and target sources observed by the KaVA (KVN and VERA Array). Experimental results show that the GFS software has effectively good performance by finding the precise delay time offset according to the comparison between the compensated delay time offset and one without compensation.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.1
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• pp.73-80
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• 2012

Recent research efforts have focused on combining high dynamic range imaging with super-resolution reconstruction to enhance both the intensity range and resolution of images. The processes developed to date start with a set of multiple-exposure input images with low dynamic range (LDR) and low resolution (LR), and require several procedural steps: conversion from LDR to HDR, SR reconstruction, and tone mapping. Input images captured with irregular exposure steps have an impact on the quality of the output images from this process. In this paper, we present a simplified framework to replace the separate procedures of previous methods that is also robust to different sets of input images. The proposed method first calculates weight maps to determine the best visible parts of the input images. The weight maps are then applied directly to SR reconstruction, and the best visible parts for the dark and highlighted areas of each input image are preserved without LDR-to-HDR conversion, resulting in high dynamic range. A new luminance control factor (LCF) is used during SR reconstruction to adjust the luminance of input images captured during irregular exposure steps and ensure acceptable luminance of the resulting output images. Experimental results show that the proposed method produces SR images of HDR quality with luminance compensation.

• Composites Research
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• v.29 no.1
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• pp.1-6
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• 2016

Low-speed impact was localized on a stiffened composite structure, using 4 FBG sensors with 100 kHz-sampling rate interrogator and devised localization algorithm. The composite specimen consists of a main spar and several stringers, and the overall size of the specimen's surface is about $0.8{\times}1.2m$. Pre-stored reference data for 247 grid locations and 36 stiffener locations are gathered and used as comparison target for a random impact signal. The proposed algorithm uses the normalized cross-correlation method to compare the similarities of the two signals; the correlation results for each sensor's signal are multiplied by others, enabling mutual compensation. 20 verification points were successfully localized with a maximum error of 43.4 mm and an average error of 17.0 mm. For the same experimental setup, the performance of the proposed method is evaluated by reducing the number of sensors. It is revealed that the mutual compensation between the sensors is most effective in the case of a two sensor combination. For the sensor combination of FBG #1 and #2, the maximum localization error was 42.5 mm, with average error of 17.4 mm.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.15-21
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• 2009

Purpose : A method to estimate a real k-space trajectory based on a circuit model of the gradient system is proposed for spiral imaging. The estimated k-space trajectory instead of the ideal trajectory is used in the reconstruction to improve the image quality in the spiral imaging. Materials and Methods : Since the gradient system has self resistance, capacitance, and inductance, as well as the mutual inductance between the magnet and the gradient coils, the generated gradient fields have delays and transient responses compared to the input waveform to the gradient system. The real gradient fields and their trajectory in k-space play an important role in the reconstruction. In this paper, the gradient system is modeled with R-L-C circuits, and real gradient fields are estimated from the input to the model. An experimental method to determine the model parameters (R, L, C values) is also suggested from the quality of the reconstructed image. Results : The gradient fields are estimated from the circuit model of the gradient system at 1.5 Tesla MRI system. The spiral trajectory obtained by the integration of the estimated gradient fields is used for the reconstruction. From experiments, the reconstructed images using the estimated trajectory show improved uniformity, reduced overshoots near the edges, and enhanced resolutions compared to those using the ideal trajectory without model. Conclusion : The gradient system was successfully modeled by the R-L-C circuits. Much improved reconstruction was achieved in the spiral imaging using the trajectory estimated by the proposed model.