• Tunnel and Underground Space
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• v.19 no.3
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• pp.167-173
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• 2009

Underground storage cavern is known as the most complicated underground project because of the complexity of construction schedule, tunnel size, and geological problems. In order to optimize the construction schedule of underground storage cavern, two up-to-date technologies were applied. The first technology was 3 dimensional visualization of complicated underground structures, and the second was 4 dimensional simulation considering construction resources, geological conditions and construction schedule. This application case shows that we can achieve optimized construction schedule in the ways to optimize the number of work teams, fleets, the sequence of tunnel excavation, the commencement time of excavation and the hauling route of materials and excavated rocks. 3 dimensional modeling can help designer being able to understand the status of complicated underground structures and to investigate the geological data in the exact 3 dimensional space. Moreover, using 4 dimensional simulation, designer is able to determine the bottle neck point which appear during hauling of excavated rocks and to investigate the daily fluctuation in cost.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.482-486
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• 2009

Conventional music players offer simple replay and one way entertainment. The paper presents an algorithm to extract, within a digitally recorded music file, the temporal information of a sequence of target notes (i.e. melody). We assume to have the score (e.g. MIDI or printed score), and using this information, it becomes possible to first sequentially predict the probable location of the target notes. However, recorded music is hardly performed according to the score, especially temporally. Thus, additional analysis is carried out to hone in on the exact location of the target note from the initially predicted location. This prediction and correction process is repeated to find one note after another. This allows us to develop an interactive music player that is enacted by rhythmic interaction, and induce a new user experience, i.e. as if one is playing the music oneself.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1623-1628
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• 2009

This paper presents the development of certain highly efficient and accurate method for computing tangent curves for two-dimensional vector fields. Unlike convention methods, such as Runge-Kutta, for computing tangent curves which produce only approximations, the method developed herein produces exact values on the tangent curves based on piecewise linear variation over a triangle in 2D. This new method assumes that the vector field is piecewise linearly defined over a triangle in 2D. It is also required to decompose the rectangular cell into two triangular cells. The critical points can be easily found by solving a simple linear system for each triangle. This method is to find exit points by producing a sequence of points on the curve with the computation of each subsequent point based on the previous. Because points on the tangent curves are calculated by the explicit solution for each triangle, this new method provides correct topologies in visualizing 2D vector fields.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.214-227
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• 2003

Developing an application, it is difficult to catch an exact requirement with the conventional text-based method. It has also problems in verification and analysis at each developing stage. Therefore, if an adjustment is required with an error and change of requirement, a bad effect happen in the whole system. In this case, it also affect adversely on the developing cost and period. Meanwhile, if an analysis or verification is performed, the possibility of an error frequency reduces. Thus, not only is it easier to correct the error but also add an new requirement. This thesis embody a TCP/IP congestion control algorithm with SDL which provides automatically graphic interface, verification and analysis to each developing stage. Using SDL gave a clear representation embodiment in each developing stage and easiness of adjustment due to changing requirements or correcting errors. In addition, the stages of protocol have been certified in a simulation by verification of MSC and the results showed a possibility of developing a better TCP/IP protocol.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1027-1036
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• 2018

In this paper a new generalized space vector pulse width modulation scheme is proposed based on the principle of reverse mapping to drive the switches of multilevel inverters. This projected scheme is developed based on the middle vector of the subhexagon which holds the tip of the reference vector, which plays a major role in mapping the reference vector. A new approach is offered to produce middle vector of the subhexagon which holds tip of the reference vector in the multilevel space vector plane. By using middle vector of the subhexagon, reference vector is linked towards the inner two level sub-hexagon. Then switching vectors, switching sequence and dwell times corresponding to a particular sector of a two-level inverter are determined. After that, by using the two level stage findings, the switching vectors related to exact position of the reference vector are directly generated based on principle of the reverse mapping approach and do not need to be found at n level stage. In the reverse mapping principle, the middle vector of subhexagon is added to the formerly found two level switching vectors. The proposed generalized algorithm is efficient and it can be applied to an inverter of any level. In this paper, the proposed scheme is explained for a five-level inverter and the performance is analyzed for five level and three level inverters through MATLAB. The simulation results are validated by implementing the propose scheme on a V/f controlled three-level inverter fed induction motor using dSPACE control desk.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.187-187
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• 2003

Methylmercury (MeHg), one of the heavy metal compounds, can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. In this study, two methods, cDNA Microarray and SSH, were performed to assess the expression profile against MeHg and to identify differentially expressed genes by MeHg in neuroblastoma cell line. TwinChip Human-8K (Digital Genomics) was used with total RNA from SH-SY5Y (human neuroblastoma cell line) treated with solvent (DMSO) and 6.25 uM (IC50) MeHg. And we performed forward and reverse SSH method on mRNA derived from SH-SY5Y treated with DMSO and MeHg (6.25 uM). Differentially expressed cDNA clones were sequenced and were screened by dot blot and ribonuclease protection assay to confirm that individual clones indeed represent differentially expressed genes. These sequences were identified by BLAST homology search to known genes or expressed sequence tags (ESTs). Analysis of these sequences may provide an insight into the biological effects of MeHg in the pathogenesis of neurodegenerative disease and a possibility to develop more efficient and exact monitoring system of heavy metals as environmental pollutants.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.247-256
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• 2004

In this paper, we propose the prediction search algorithm for block matching using the temporal/spatial correlation of the video sequence and the renter-biased property of motion vectors The proposed algorithm determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(Sum of Absolute Difference) value by the predicted motion vector from the same block of the previous frame and the predictor candidate pint in each search region and the predicted motion vector from the neighbour blocks of the current frame. And the searching process after moving the starting point is processed a adaptive search pattern according to the magnitude of motion vector Simulation results show that PSNR(Peak-to-Signal Noise Ratio) values are improved up to the 0.75dB as depend on the video sequences and improved about 0.05∼0.34dB on an average except the FS (Full Search) algorithm.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.55-67
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• 1998

This paper presents an automatic facial feature point extraction algorithm in sequential color images. To extract facial region in the video sequence, a moving color detection technique is proposed that emphasize moving skin color region by applying motion detection algorithm on the skin-color transformed images. The threshold value for the pixel difference detection is also decided according to the transformed pixel value that represents the probability of the desired color information. Eye candidate regions are selected using both of the black/white color information inside the skin-color region and the valley information of the moving skin region detected using morphological operators. Eye region is finally decided by the geometrical relationship of the eyes and color histogram. To decide the exact feature points, the PCA(Principal Component Analysis) is used on each eye and mouth regions. Experimental results show that the feature points of eye and mouth can be obtained correctly irrespective of background, direction and size of face.

• Clinical and Experimental Pediatrics
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• v.60 no.6
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• pp.167-174
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• 2017

Mycoplasma pneumoniae pneumonia (MPP) is one of the most common forms of community-acquired pneumonia in children and adolescents. Outbreaks of MPP occur in 3- to 7-year cycles worldwide; recent epidemics in Korea occurred in 2006-2007, 2011, and 2015-2016. Although MPP is known to be a mild, self-limiting disease with a good response to macrolides, it can also progress into a severe and fulminant disease. Notably, since 2000, the prevalence of macrolide-resistant MPP has rapidly increased, especially in Asian countries, recently reaching up to 80%-90%. Macrolide-resistant Mycoplasma pneumoniae (MRMP) harbors a point mutation in domain V of 23S rRNA with substitutions mainly detected at positions 2063 and 2064 of the sequence. The excessive use of macrolides may contribute to these mutations. MRMP can lead to clinically refractory pneumonia, showing no clinical or radiological response to macrolides, and can progress to severe and complicated pneumonia. Refractory MPP is characterized by an excessive immune response against the pathogen as well as direct injury caused by an increasing bacterial load. A change of antibiotics is recommended to reduce the bacterial load. Tetracyclines or quinolones can be alternatives for treating MRMP. Otherwise, corticosteroid or intravenous immunoglobulin can be added to the treatment regimen as immunomodulators to downregulate an excessive host immune reaction and alleviate immune-mediated pulmonary injury. However, the exact starting time point, dose, or duration of immunomodulators has not been established. This review focuses on the mechanism of resistance acquisition and treatment options for MRMP pneumonia.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.47-55
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• 1994

This paper investigates the performance analysis of the packet DS/SS receiver with a PJED(phase-jump error detector) using the block signal processing(BSP) methods. The conventional packet DS/SS block receiver has a high probability of mistaking the phase-jump detection, which causes the frequency estimation error. The conventional receiver uses a Matched-Pulse Timing Extractor which has a complicated structure. The proposed packet DS/SS block receiver with the PJED which uses libearity of the phase has little probability of mistaking the phase-jump detection. The proposed Matched Pulse Timing Extractor gas the more simple structure but obtains the same performance on the exact matched-pluse timing as the conventional one does. The simulation results show that the proposed receiver gives about 2dB improvement in the BER compared with the conventional receiver.