• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.493-496
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• 2005

The PMU (Payload Management Unit) in MSC (Multi-Spectral Camera) is the main subsystem for the management, control and power supply of the MSC payload operation. The PMU shall handle the communication with the BUS (Spacecraft) OBC (On Board Computer) for the command, the telemetry and the communications with the various MSC units. The PMU will perform that distributes power to the various MSC units, collects the telemetry reports from MSC units, performs thermal control of the EOS (Electro-Optical Subsystem), performs the NUC (Non-Uniformity Correction) function of the raw imagery data, and rearranges the pixel data and output it to the DCSU (Data Compression and Storage Unit). The BUS provides high voltage to the MSC. The PMU is connected to primary and redundant BUS power and distributes the high unregulated primary voltages for all MSC sub-units. The PSM (Power Supply Module) is an assembly in the PMU implements the interface between several channels on the input. The bus switches are used to prevent a single point system failure. Such a failure could need the PSS (Power Supply System) requirement to combine the two PSM boards' bus outputs in a wired-OR configuration. In such a configuration if one of the boards' output gets shorted to ground then the entire bus could fail thereby causing the entire MSC to fail. To prevent such a short from pulling down the system, the switch could be opened and disconnect the short from the bus. This switch operation is controlled by the BUS.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.1025-1032
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• 2003

Percentiles are convenient measures of the entire range of values of simulation outputs. However, unlike means and standard deviations, the observations have to be stored since calculation of percentiles requires several passes through the data. Thus, percentile (PE) requires a large amount of computer storage and computation time. The best possible computation time to sort n observations is (O($nlog_{2}n$)), and memory proportional to n is required to store sorted values in order to find a given order statistic. Several approaches for extimating percentiles in RS(regenerative simulation) and non-RS, which can avoid difficulties of PE, have been proposed in [11, 12, 21]. In this paper, we implemented these three approaches known as : leanear PE, batching PE, spectral $P^2$ PE in the context of sequential steady-state simulation. Numerical results of coverage analysis of these PE approachs are present.

• Journal of IKEEE
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• v.24 no.4
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• pp.1122-1128
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• 2020

Bandwidth Extension refers to restoring and expanding a narrow band signal(NB) that is damaged or damaged in the encoding and decoding process due to the lack of channel capacity or the characteristics of the codec installed in the mobile communication device. It means converting to a wideband signal(WB). Bandwidth extension research mainly focuses on voice signals and converts high bands into frequency domains, such as SBR (Spectral Band Replication) and IGF (Intelligent Gap Filling), and restores disappeared or damaged high bands based on complex feature extraction processes. In this paper, we propose a model that outputs an bandwidth extended signal based on an autoencoder among deep learning models, using the residual connection of one-dimensional convolutional neural networks (CNN), the bandwidth is extended by inputting a time domain signal of a certain length without complicated pre-processing. In addition, it was confirmed that the damaged high band can be restored even by training on a dataset containing various types of sound sources including music that is not limited to the speech.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.6-10
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• 2007

Classification of hyperspectral images is challenging. A very high dimensional input space requires an exponentially large amount of data to adequately and reliably represent the classes in that space. In other words in order to obtain statistically reliable classification results, the number of necessary training samples increases exponentially as the number of spectral bands increases. However, in many situations, acquisition of the large number of training samples for these high-dimensional datasets may not be so easy. This problem can be overcome by using multiple classifiers. In this paper we compared the effectiveness of two approaches for creating multiple classifiers, feature selection and feature extraction. The methods are based on generating multiple feature subsets by running feature selection or feature extraction algorithm several times, each time for discrimination of one of the classes from the rest. A maximum likelihood classifier is applied on each of the obtained feature subsets and finally a combination scheme was used to combine the outputs of individual classifiers. Experimental results show the effectiveness of feature extraction algorithm for generating multiple classifiers.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.41-53
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• 2015

In meteorological field, many researchers have tried to develop micro scale weather analysis modules for providing real-time weather information service in the metropolitan area. This effort enables us to cope with various economic and social harms coming from serious change in the micro meteorology of a metropolitan area due to rapid urbanization such as quantitative expansions in its urban activity, growth of population, and building concentration. The accuracy of the micro scale weather analysis modules (MSWAM) directly related to usefulness and quality of the real-time weather information service in the metropolitan area. This paper design a evaluation system along with verification tools that sufficiently accommodate spatio-temporal characteristics of the outputs of the MSWAM. For this we proposes a test for the equality of mean vectors of the output series of the MSWAM and corresponding observed time series by using a spectral analysis technique. As a byproduct, a time series cluster analysis method, using a function of the test statistic as the distance measure, is developed. A real data application is given to demonstrate the utility of the method.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.693-703
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• 2009

The complex formation of anti-inflamatory drug piroxicam (PX, 4-hydroxy-2-methyl-N-2--pridyl-2H-1,2-benzothiazine-3-carboxadiamide-1,1-dioxide) with transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) in methanol(MeOH)/water binary mixtures were studied by spectrophotometric method at 25$^{\circ}C$, constant pH = 5.0 and I = 0.1 M. The computer program SQUAD was used to extract the desired information from the spectral data. The outputs of the fitting processes were stability constants, standard deviations of the estimated stability constants, concentration distribution diagrams and spectral profiles of all species. The sequence of the stability constants of PX complexes with Co(II), Ni(II), Cu(II) and Zn(II) follow the Cu(II) > Co(II) > Ni(II) ${\approx}$ Zn(II) order. This may be due to different geometry tendencies of these metal ions. The acidity constants of the PX were also determined under above condition from its absorption spectra at different pH values. The computer program DATAN was used for determination of acidity constants of PX. The validity of the obtained acidity constants was checked by a well known computer program SPECFIT/32. The effects of the different parameters like solvent nature, cations characteristics on the stability and acidity constants were thoroughly discussed.

• Ocean Systems Engineering
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• v.8 no.1
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• pp.1-20
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• 2018

The target area of the proposed study, Mamaia beach, is a narrow stretch of sand barrier island that sits between the Siutghiol Lake and the Black Sea. In the northern part of the bay, is located the Midia Port, where between 1966 and 1971 a long extension of 5 km of the offshore was built. Because of this extension, the natural flow of sediments has been significantly changed. Thus, the southern part of the Mamaia Bay had less sand nourishment which meant that the coast was eroding and to prevent it a protection of six dikes was built. After approximately forty years of coastal erosion, the south of the Mamaia Bay had in 2016 a new protection scheme, which includes first of all the beach nourishment and a new dike structure (groins scheme for protection) to protect it. From this perspective, the objective of the proposed study is to evaluate the effectiveness of the old Master plan against the new one by modeling the outcome of the two scenarios and to perform a comparison with a third one, in which the protection dikes do not exist and only the artificial nourishment has been done. In order to assess the wave processes and the current patterns along the shoreline, a complex computational framework has been applied in the target area. This joins the SWAN spectral phase averaged model with the 1D surf model. Furthermore, new UAV technology was also used to map out, chart and validate the numerical model outputs within the target zone for a better evaluation of the trends expected in the shoreline dynamics.

• Journal of the Korean earth science society
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• v.40 no.3
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• pp.212-226
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• 2019

This study derived spectral Lambertian Equivalent Reflectance (LER) over East Asia from the observations of Ozone Monitoring Instrument (OMI) onboard polar-orbit satellite Aura. The climatological (October 2004-September 2007) LER values were compared with the surface reflectance products of OMI or MODerate resolution Imaging Spectroradiometer (MODIS) in terms of the atmosphere-environment variables as follows: wavelength (UV, visible), surface properties (land, ocean), and cloud filtering. Four kinds of LER outputs in the UV and visible region (328-500 nm) were retrieved based on the averages of lowest (1, 5, and 10%) surface reflectance values as well as the minimum reflectance. The average of the lowest 10% among them was in best agreement with the OMI product: correlation coefficient (0.88), RMSE (1.0%) and mean bias (-0.3%). The 10% average and OMI LER values over ocean were 2% larger in UV than in visible, while the values over land were 1% smaller. The LER variability on the wavelength and surface property was highest (~3%) in the condition of both land and visible, particularly in the ice-cap and desert regions. The minimum reflectance values over the oceanic and inland sample areas overestimated the MODIS product by 1.4%. This high-resolution MODIS observations were effective in removing cloud contamination. The relative errors of the 10% average to MODIS were smaller (-0.6%) over ocean but larger (1.5%) over land than those of the OMI product to MODIS. The reduced relative error in the OMI product over land may result from additional cloud filtering using the Landsat data. This study will be useful when retrieveing the surface reflectance from geostationary-orbit environmental satellite (e.g., Geostationary Environment Monitoring Spectrometer; GEMS).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.3
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• pp.199-208
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• 2019

As the number of available satellites increases and technology advances, image information outputs are becoming increasingly diverse and a large amount of data is accumulating. In this study, we propose a change detection method for high-resolution satellite images that uses transfer learning and a deep learning network to overcome the limit caused by insufficient training data via the use of pre-trained information. The deep learning network used in this study comprises convolutional layers to extract the spatial and spectral information and convolutional long-short term memory layers to analyze the time series information. To use the learned information, the two initial convolutional layers of the change detection network are designed to use learned values from 40,000 patches of the ISPRS (International Society for Photogrammertry and Remote Sensing) dataset as initial values. In addition, 2D (2-Dimensional) and 3D (3-dimensional) kernels were used to find the optimized structure for the high-resolution satellite images. The experimental results for the KOMPSAT-3A (KOrean Multi-Purpose SATllite-3A) satellite images show that this change detection method can effectively extract changed/unchanged pixels but is less sensitive to changes due to shadow and relief displacements. In addition, the change detection accuracy of two sites was improved by using 3D kernels. This is because a 3D kernel can consider not only the spatial information but also the spectral information. This study indicates that we can effectively detect changes in high-resolution satellite images using the constructed image information and deep learning network. In future work, a pre-trained change detection network will be applied to newly obtained images to extend the scope of the application.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.49-60
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• 2002

Receive dynamic focusing with an array transducer can provide near optimum resolution only in the vicinity of transmit focal depth. A customary method to increase the depth of field is to combine several beams with different focal depths, with an accompanying decrease in the frame rate. In this Paper. we Present a simultaneous multiple transmit focusing method in which chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in a sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels. and the crossorelation function of any Pair of the signals has values smaller than the sidelobe levels of each autocorrelation function. This means that each chirp signal can be separated from the combined received signals and compressed into a short pulse. which is then individually focused on a separate receive beamformer. Next. the individually focused beams are combined to form a frame of image. Theoretically, any two chirp signals defined over two nonoverlapped frequency bands are mutually orthogonal In the present work. however, a tractional overlap of adjacent frequency bands is permitted to design more chirp signals within a given transducer bandwidth. The elevation of the rosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals We also observe that the Proposed method provides better images when the low frequency chirp is focused at a near Point and the high frequency chirp at a far point along the depth. better lateral resolution is obtained at the far field with reasonable SNR due to the SNR gain in Pulse compression Imaging .