• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.6
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• pp.583-590
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• 1999

We propose the reusability decision model of the object-oriented components, which can decide the potentiality of reusability of the object-oriented components actively. Fisrt, we select attributes for the reusability decision of the object-oriented components. Then, we acquire information from the reused components based on the quality measures and criteria proposed by many researches. Lastly, we generate algorithm for the reusability decision of the object-oriented components from the acquired information employing rough set.

• Communications for Statistical Applications and Methods
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• v.22 no.2
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• pp.173-180
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• 2015

We propose a selection procedure of principal components in principal component regression. Our method selects principal components using variable selection procedures instead of a small subset of major principal components in principal component regression. Our procedure consists of two steps to improve estimation and prediction. First, we reduce the number of principal components using the conventional principal component regression to yield the set of candidate principal components and then select principal components among the candidate set using sparse regression techniques. The performance of our proposals is demonstrated numerically and compared with the typical dimension reduction approaches (including principal component regression and partial least square regression) using synthetic and real datasets.

• Communications for Statistical Applications and Methods
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• v.25 no.3
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• pp.275-282
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• 2018

This paper discusses the use of projections for the sums of squares in the analyses of variance for two-way nested design data. The model for this data is assumed to only have random effects. Two different sizes of experimental units are required for a given experimental situation, since nesting is assumed to occur both in the treatment structure and in the design structure. So, variance components are coming from the sources of random effects of treatment factors and error terms in different sizes of experimental units. The model for this type of experimental situation is a random effects model with more than one error terms and therefore estimation of variance components are concerned. A projection method is used for the calculation of sums of squares due to random components. Squared distances of projections instead of using the usual reductions in sums of squares that show how to use projections to estimate the variance components associated with the random components in the assumed model. Expectations of quadratic forms are obtained by the Hartley's synthesis as a means of calculation.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.4
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• pp.155-164
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• 2015

In this paper, we propose a new color interpolation method based on trilateral filter approach, which not only preserve the high-frequency components(image edge) while interpolating the missing raw data of color image(bayer data pattern), but also immune to the image noise components and better preserve the detail of the low-frequency components. The method is the trilateral filter approach applying a gradient to the low frequency components of the image signal in order to preserve the high-frequency components and the detail of the low-frequency components through the measure of the freedom of similarity among adjacent pixels. And also we perform Gaussian smoothing to the interpolated image data in order to robust to the noise. In this paper, we compare the conventional demosaicing algorithm and the proposed algorithm using 10 test images in terms of hue MAD, saturation MAD and CPSNR for the objective evaluation, and verify the performance of the proposed algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.1
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• pp.39-48
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• 1999

An economic procedure of selective assembly is proposed when a product is composed of two mating components. The major qualify characteristic of the product is the clearance between the two components. The components are divided into several classes prior to assembly. The component characteristics are assumed to be independently and normally distributed with equal variance. The procedure is designed so that the proportions of both components in their corresponding classes are the same. A cost model is developed based on a quadratic loss function and methods of obtaining the optimal class limits as well as the optimal number of classes are provided. Formulas for obtaining the proportion of rejection and the unavailability of mating components are also provided. The proposed model is compared with the equal width and the equal area partitioning methods using a numerical example.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.35-41
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• 2014

Real-life time series characteristic data has significant amount of non-stationary components, especially periodic components in nature. Extracting such components has required many ad-hoc techniques with external parameters set by users in a case-by-case manner. In this study, we used Empirical Mode Decomposition Method from Hilbert-Huang Transform to extract them in a systematic manner with least number of ad-hoc parameters set by users. After the periodic components are removed, the remaining time-series data can be analyzed with traditional methods such as ARIMA model. Then we suggest a different way of setting control chart limits for characteristic data with periodic components in addition to ARIMA components.

• ETRI Journal
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• v.28 no.5
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• pp.648-651
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• 2006

In this letter we present a right-angle-bent coplanar waveguide (CPW) which we developed for the application of the driver amplifier-integrated (DAI) 40 Gbps traveling wave electroabsorption modulated laser module. The developed CPW realized parallel progression of the radio frequency (RF) and light using a dielectric overlay structure and wedge bonding on the bending section. The measured $S_{11}$ and $S_{21}$ of the developed CPW were kept below-10 dB up to 35 GHz and -3 dB up to 43 GHz, respectively. These measured results of the CPW were in good agreement with the simulation results and demonstrated the applicability of the CPW to the 40 Gbps communication module.

• ETRI Journal
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• v.28 no.5
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• pp.545-554
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• 2006

A widely tunable multi-channel grating cavity laser is proposed and experimentally demonstrated. The device is implemented in Littman configuration with an echelle grating based on Rowland circle construction and realized by monolithically integrating all elements in an InP substrate. Lasing wavelength is selected by turning on an amplifier and the appropriate channel element in the array, and it is tuned by controlling light deflection electrically. The 6-channel device exhibits a tuning range of about 50 nm with a side mode suppression ratio of more than 30 dB. This is accomplished by adjusting the applied current of the dispersive element and phase control section.

• ETRI Journal
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• v.34 no.2
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• pp.280-283
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• 2012

By inserting $H_2O$ treatment steps during atomic layer deposition of a ZnO layer, the turn-on voltage shift from negative bias stress (NBS) under illumination was reduced considerably compared to that of a device that has a continuously grown ZnO layer without any treatment steps. Meanwhile, treatment steps without introducing reactive gases, and simply staying under a low working pressure, aggravated the instability under illuminated NBS due to an increase of oxygen vacancy concentration in the ZnO layer. From the experiment results, additional oxidation of the ZnO channel layer is proven to be effective in improving the stability against illuminated NBS.

• ETRI Journal
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• v.31 no.2
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• pp.228-230
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• 2009

InP-based planar waveguide 48-channel concave grating demultiplexers with a channel spacing of 0.8 nm (100 GHz) are described and demonstrated. Polarization insensitivity and flattened spectral response are successfully achieved by the introduction of a polarization compensator and a two-focus grating, respectively. The fabricated device shows a polarization-dependent wavelength shift of less than 20 pm and a -3 dB spectral width of about 0.55 nm (68.75 GHz) over all channels.