• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.263-269
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• 2015

Digital watermarking is imperceptible and statistically undetectable information embeds into digital data. Most information in digital audio watermarking schemes have used binary random sequences. The embedded binary random sequence distorts and modifies the original data while it plays a vital role in security. In this paper, a binary random sequence to improve imperceptibility in perceptual region of the human auditory system is proposed. The basic idea of this work is a modification of a binary random sequence according to the frequency analysis of adjacent binary digits that have different signs in the sequence. The canonical signed digit code (CSDC) is also applied to modify a general binary random sequence and the pair-matching function between original and its modified version. In our experiment, frequency characteristics of the proposed binary random sequence was evaluated and analyzed by Bark scale representation of frequency and frequency gains.

• Environmental Engineering Research
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• v.22 no.4
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• pp.339-346
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• 2017

The objective of this study is the evaluation of the performance of a large-scale respirometer (LSR) of 17.7 L in the determination of the methane generation rate constant (k) values. To achieve this objective, a comparison between anaerobic (GB21) and LSR tests was conducted. The data were modeled using a linear function, and the resulting correlation coefficient ($R^2$) of the linear regression is 0.91. This result shows that despite the aerobic conditions, the biodegradability values that were obtained from the LSR test produced results that are similar to those from the GB21 test. In this respect, the LSR test can be an indicator of the anaerobic biodegradability for landfill waste. In addition, the results show the high repeatability of the tests with an average coefficient of variance (CV) that is lower than 10%; furthermore, the CV for the LSR is lower than that of the GB21, which indicates that the LSR-test method could provide a better representation of waste samples. Therefore, the LSR method allows for both the prediction of the long-term biodegradation potential in a shorter length of time and the reduction of the sampling errors that are caused by the heterogeneity of waste samples. The k values are $0.156y^{-1}$ and $0.127y^{-1}$ for the cumulative biogas production (GB21) and the cumulative oxygen uptake for the LSR, respectively.

• Journal of KIISE:Databases
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• v.33 no.5
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• pp.437-452
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• 2006

In this paper, we propose an extended XPath specification which includes a special matching character '%' used in the LIKE operation of SQL in order to solve the difficulty of writing some queries to filter element contents well, using the previous XPath specification. We also present a novel technique for filtering a collection of document-centric XMLs, called Pfilter, which is able to exploit the extended XPath specification. Owing to sharing the common prefix characters of the operands in value-based predicates, the Pfilter improves the performance in processing those. We show several performance studies, comparing Pfilter with Yfilter in respect to efficiency and scalability as using multi-query processing time (MQPT), and reporting the results with respect to inserting, deleting, and processing of value-based predicates. In conclusion, our approach provides a core algorithm for evaluating the contains() function of XPath queries in previous XML filtering researches, and a foundation for building XML-based distributed information systems.

• The Journal of the Korea Contents Association
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• v.3 no.3
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• pp.11-18
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• 2003

Error diffusion is a procedure for generating high quality bilevel images from continuous-tone images but blurs the edge information. To solve this problem, we propose the improved method appling edge enhanced weights based on local characteristic of the original images. We consider edge information as local characteristic. First, we produce edges by appling 3$\times$3 sobel operator to the original image. The edge is normalized from 0 to 1. Edge information weights are computed by using sinusoidal function and the normalized edge information. The edge enhanced weights are computed by using edge information weights multiplied input pixels. The proposed method is compared with conventional methods by measuring the edge correlation and quality of the recovered images from the halftoned images. The proposed method provides better quality than the conventional method due to the enhanced edge and represents efficiently the detail edge. Also, the proposed method is improved in edge representation than the conventional method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5243-5250
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• 2013

BIM(Building Information Modeling) enables 3D model-base management for all information produced by construction project during its life cycle. Also as a national policy, BIM has been institutionalized as design criteria. But, on the matter of 2D drawing using BIM software (Revit Architecture), it has been recognized as difficult to realize the same quality drawing drawn by CAD. The purpose of this study is verifying the possibility of printable design drawing implemented by BIM software at the same quality of 2D shop drawing drawn by 2D CAD. Through the analysis of basic design elements of 3D BIM software and 2D CAD software, with the case of partial cross sectional drawing which is most faithful representation of the basic design elements, this study find out that the 3D BIM software can produce the same quality 2D printable drawing utilizing its implicit function.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.48-62
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• 1998

Seasonal volume transport on the Texas-Louisiana continental shelf is investigated in terms of objectively fitted transport streamfunction fields based on the current meter data of the Texas­Louisiana Shelf Circulation and Transport Processes Study. Adopted here for the objective mapping is a method employing a two-dimensional truncated Fourier representation of the streamfunction over a domain, with the amplitudes determined by least square fit of the observation. The fitting was done with depth-averaged flow rather than depth-integrated flow to reduce the root-mean-square error. The fitting process filters out $11\%$ of the kinetic energy in the monthly mean transport fields. The shelf-wide pattern of streamfunction fields is similar to that of near-surface velocity fields over the region. The nearshore transport, about 0.1 to 0.3 Sv $(1 Sv= 10^6\;m^3/sec)$, is well correlated with the seasonal signal of along-shelf wind stress. The spring transport is weak compared to other seasons in the inner shelf region. The transport along the shelf break is large and variable. In the southwestern shelf break, transport amounts up to 4.7 Sv, which is associated with the activities of the encroaching of energetic anticyclonic eddies originated in Loop Current of the eastern Gulf of Mexico. The first empirical orthogonal function (EOF) of streamfunction variability contains $67.3\%$ of the variance and shows a simple, shelf-wide, along-shelf pattern of transport. The amplitude evolution of the first EOF is highly correlated (correlation coefficient: 0.88) with the evolution of the along-shelf wind stress. This provides strong evidence that the large portion of seasonal variation of the shelf transport is wind-forced. The second EOF contains $23.7\%$ of the variance and shows eddy activities at the southwestern shelf break. The correlation coefficient between the amplitudes of the second EOF and wind stress is 0.42. We assume that this mode is coupled a periodic inner shelf process with a non-periodic eddy process on the shelf break. The third EOF (accounting for $7.2\% of the variance) shows several cell structures near the shelf break associated with the variability of the Loop Current Eddies. The amplitude time series of the third EOF show little correlation with the along-shelf wind.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.4
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• pp.255-262
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• 2013

In this paper, a shape design sensitivity analysis(DSA) method is presented for Mindlin plates using an isogeometric approach. The isogeometric method possesses desirable advantages; the representation of exact geometry and the higher order inter-element continuity, which lead to the fast convergence of solution as well as accurate sensitivity results. Unlike the finite element methods using linear shape functions, the isogeometric method considers the exact normal vector and curvature of the CAD geometry, taking advantages of higher order NURBS basis functions. A selective reduced integration(SRI) technique is incorporated to overcome the difficulty of 'shear locking' phenomenon. This simple technique is surprisingly helpful for the accuracy of the isogeometric shape sensitivity without complicated formulation. Through the numerical examples of plate bending problems, the accuracy of the proposed isogeometric analysis method is compared with that of finite element one. Also, the isogeometric shape sensitivity turns out to be very accurate when compared with finite difference sensitivity.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.621-628
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• 2017

The efficiency of implementation of the arithmetic operations in finite fields depends on the choice representation of elements of the field. It seems that from this point of view normal bases are the most appropriate, since raising to the power 2 in $GF(2^n)$ of characteristic 2 is reduced in these bases to a cyclic shift of the coordinates. We, in this paper, introduce our algorithm to transform fastly the conventional bases to normal bases and present the result of H/W implementation using the algorithm. We also propose our algorithm to calculate the multiplication and inverse of elements with respect to normal bases in $GF(2^n)$ and present the programs and the results of H/W implementations using the algorithm.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.363-370
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• 2002

OPKFDD (Ordered Pseudo-Kronecker Functional Decision Diagram) is one of ordered-DDs (Decision Diagrams) in which each node can take one of three decomposition types : Shannon, positive Davio and negative Davio decompositions. Whereas OBDD (Ordered Binary Decision Diagram) uses only the Shannon decomposition in each node, OPKFDD uses the three decompositions and generates representations of functions with smaller number of nodes than other DDs. However, this leads to the extreme difficulty of getting an optimal solution for the minimization of OPKFDD. Since an appropriate decomposition type has to be chosen for each node, the size of the representation is decided by the selection of the decomposition type. We propose a heuristic method to generate OPKFDD efficiently from the OBDD of the given function and the algorithm of the decision of decomposition type for a given variable ordering. Experimental results demonstrate the performance of the algorithm.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.3
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• pp.123-138
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• 2004

The objective of this study is to review the expressive effect of fashion illustrations and to enlarge its expressive range by analysing the correlations between fashion illustrations and surrealistic expressive characteristics. The results are as follows. The surrealistic expressive methods of fashion illustration such as depaysement and automatism have been used by many foreign and domestic fashion illustrators. I think that these methods reinforce the subjective aspect of expressive effects and enlarge the transmitting function of fashion message. The elements of expression are divided into color, texture, shape/form and space. Subjective colors rather than natural colors are used for the surrealistic expressive effect of color in fashion illustrations, and illusion of space is expressed by the change of brightness. The surrealistic expressive effect in fashion illustrations distorted the experience of factual texture and disturbed the visual texture. The use of tactile texture presented strange effects perspectively. The objects of shape in fashion illustrations were mainly human body. The form of human body presents reconstituted and reinterpreted figure by transformation or distortion according to the intention of the artist rather than realistic and physical form. In fashion illustration, the transformation of the human body itself whose body parts get separated, superposition of exterior material and human body, and the distortion of human body by the change are done. Space is where background and shapes are inter-penetrated because they are ambiguous and untransparent, and where all are in disorder and unbalance. The method of projection uses distance perspective, multiple perspective and amplified perspective representation, and forms a psychological space feeling. And I think the use of surrealistic expressive methods are very useful for the subjective sensitiveness and the transmission of a fashion message, and presents a possibility to develop a new expressive method.