• Journal of information and communication convergence engineering
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• 제9권5호
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• pp.487-490
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• 2011

This paper presents splitting and merging algorithm based on adaptive thresholding. The algorithm first divides the image into blocks, and then compares each block using the calculated thresholding value. The blocks which are same are merged using the certain threshold value and different blocks are split unless it satisfies the threshold value. When the block has been merged, maximum and minimum block sizes are determined then the average block size is determined. After the average block size is determined the average intensity and standard deviation of average block is calculated. The process of thresholding is applied to binarize the image. Finally, the experimental results show that the proposed method distinguishes clearly the background with text in the document image.

• 전자공학회논문지B
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• 제31B권1호
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• pp.72-80
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• 1994

In this paper, a new variable block-size transform coding algorithm using information of segmentation is proposed. In general variable block-size transform coding algorithms, the information which is used to form variable blocks is thrown away, but in the proposed algorithm, the information of segmentation which is composed of texture and contour information is maintained for efficient coding. That is, the number of blocks can be reduced by contour information, a DC component of block can be predicted by texture information, and the region compensation, which reduces mean difference between regions, using texture and contour information can diminish the magnitude of AC components. The result is that the proposed algorithm has improved highly the coding efficiency of DC and AC components.

• 한국의학물리학회지:의학물리
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• 제1권1호
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• pp.61-68
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• 1990

We have designed the calculation model(AMC method) of electron output for the cut-out fieldsand studied the influence of shielding block size. The output of electron was measured in the water phantom at dmax, for 20 $\times$ 20cm$^2$ cone size electron beams from CL/1800 linear accelerator(Varian, USA), Which generates the energy of 6, 9, 12, 15 and 18MeV electron beams. The shielding blocks were rectangular or squre shaped, low melting point alloy. We can predict the output from the arbitrarily rectangular shaped block within 1% error. by using the AMC method, which considers the contribution of the collimator(block) scatter and the phantom scatter.

• 전자공학회논문지B
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• 제33B권10호
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• pp.120-129
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• 1996

This paper presents an efficient block segmentation and classification using the edge information of the document image. We extract four prominent features form the edge gradient and orientaton, all of which, and thereby the block clssifications, are insensitive to the background noise and the brightness variation of of the image. Using these four features, we can efficiently classify a document image into the seven categrories of blocks of small-size letters, large-size letters, tables, equations, flow-charts, graphs, and photographs, the first five of which are text blocks which are character-recognizable, and the last two are non-character blocks. By introducing the clumn interval and text line intervals of the document in the determination of th erun length of CRLA (constrained run length algorithm), we can obtain an efficient block segmentation with reduced memory size. The simulation results show that the proposed algorithm can rigidly segment and classify the blocks of the documents into the above mentioned seven categories and classification performance is high enough for all the categories except for the graphs with too much variations.

• 한국지역사회생활과학회지
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• 제28권1호
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• pp.69-79
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• 2017

The purpose of this study was to compare fitting of the upper garment by brassiere cup size and types of bodice block. This study conducted a 3D virtual garment system by applying three types of bodice block (I, II, III) and experimental pattern of the bodice block to 3D avatars of four individuals with the following measurements: under bust circumference of 73.5 cm and bust circumferences of 83.5 cm, 86.0 cm, 88.5 cm, and 91.0cm. The results of the study were as follows. First, for 83.5 cm bust circumference (A Cup), appearance of the three types of bodice block (I, II, III) was appropriate. However, as bust circumference increased in size, shape became inappropriate. The depth and width of the armhole, within 15 cm and 11 cm, respectively, were found to be appropriate. In case of 91.0 cm bust circumference (D Cup), all three bodices (I, II, III) were inappropriate. Second, the results of the draft of the experimental patterns of the bodice block of bust circumference measuring 83.5 cm, 86.0 cm, 88.5 cm, and 91.0 cm in the 3D avatars of the four individuals revealed similarities in the frontal view of the silhouette in the four avatars; in the case of the lateral view of the silhouette, lateral width grew wider as bust circumference of the silhouette became larger, but the shape of armhole showed no changes. The depth of the armhole showed little changes from 15.1 cm to 15.22 cm, and the height of sleeve (armscye depth 13.6 cm within +2 cm) remained similar. The difference in width of the armhole from 11.26 cm to 11.37 cm was rather small. The width of the upper sleeve (8.97 cm) seemed to be appropriate as it remained within the 2-3 cm boundary.

• 융합보안논문지
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• 제19권1호
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• pp.67-78
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• 2019

본 논문에서는 가변 크기 블록 기반의 새로운 얼굴 특징 표현 방법을 제안한다. 기존 외형 기반의 얼굴 표정 인식 방법들은 얼굴 특징을 표현하기 위해 얼굴 영상 전체를 균일한 블록으로 분할하는 uniform grid 방법을 사용하는데, 이는 다음 두가지 문제를 가지고 있다. 얼굴 이외의 배경이 포함될 수 있어 표정을 구분하는 데 방해 요소로 작용하고, 각 블록에 포함된 얼굴의 특징은 입력영상 내 얼굴의 위치, 크기 및 방위에 따라 달라질 수 있다. 본 논문에서는 이러한 문제를 해결하기 위해 유의미한 표정변화가 가장 잘 나타내는 블록의 크기와 위치를 결정하는 가변 크기 블록 방법을 제안한다. 이를 위해 얼굴의 특정점을 추출하여 표정인식에 기여도가 높은 얼굴부위에 대하여 블록 설정을 위한 기준점을 결정하고 AdaBoost 방법을 이용하여 각 얼굴부위에 대한 최적의 블록 크기를 결정하는 방법을 제시한다. 제안된 방법의 성능평가를 위해 LDTP를 이용하여 표정특징벡터를 생성하고 SVM 기반의 표정 인식 시스템을 구성하였다. 실험 결과 제안된 방법이 기존의 uniform grid 기반 방법보다 우수함을 확인하였다. 특히, 제안된 방법이 형태와 방위 등의 변화가 상대적으로 큰 MMI 데이터베이스에서 기존의 방법보다 상대적으로 우수한 성능을 보여줌으로써 입력 환경의 변화에 보다 효과적으로 적응할 수 있음을 확인하였다.

• 전자공학회논문지CI
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• 제49권4호
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• pp.89-96
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• 2012

지능형 서비스 분야에 있어 3D맵은 유용하고 다양한 정보를 제공할 수 있다. 기존의 삼차원 공간에 대한 연구 방법들은 제공하는 데이터가 원초적이고 처리량이 방대하여 지능형 서비스의 실시간 처리에는 적절하지 못하다. 본 논문에서는 전방의 공간에 대하여 스테레오 정합 연산의 결과인 거리정보 이미지를 바탕으로 블록 기반의 맵을 구성하여 해당 공간의 다양한 정보를 제공할 수 있는 방안을 제안한다. 블록기반 3D맵은 객체율과 블록크기의 2개의 중요한 변수를 가진다. 객체율은 하나의 블록에서 공간대비 객체의 픽셀수의 비율로써 블록종류를 결정한다. 블록크기는 정육면체로 구성되는 개별 블록의 한 변의 픽셀수를 나타내며, 블록의 크기를 결정한다. 실험을 통하여 블록기반 3D맵은 기존의 거리정보 이미지에 비하여 노이즈와 데이터양을 효과적으로 감소시키는 것을 확인하였다. $320{\times}240$크기의 거리정보 이미지에 대하여 블록크기는 $40{\times}40$, 객체율은 30%에서 50%로 설정하였을 때 가장 정합율이 높은 블록기반 3D맵을 취득할 수 있음을 확인하였다. 블록기반 3D맵은 지능형 서비스분야에서 사용하기 용이하고 다양한 새로운 서비스를 도출할 수 있는 고부가가치를 갖는 정보를 제공할 수 있다.

• 전기전자학회논문지
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• 제6권2호
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• pp.111-118
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• 2002

본 논문은 가변 스텝사이즈 LMS (Least Mean Square) 알고리듬의 스텝사이즈 결정시 추가되는 계산량을 줄이기 위해 가변 블록을 사용하는 방법을 제안한다. 이 방법에서는 블록 길이를 스텝사이즈의 변화에 반비례하도록 하여 기존의 가변 스텝사이즈 알고리듬의 수렴속도와 정상상태 오차에 대해 성능의 저하 없이 계산량을 줄이고자 한다. 그리고 평균이 영인 백색 가우시안 입력신호 환경하에서 LMS 기반 적응 알고리듬의 초기 스텝사이즈를 최적으로 구하는 방법을 제안한다. 제안한 방법의 우수성을 입증하기 위한 컴퓨터 모의 실험을 통해 기존의 가변 스텝사이즈 알고리듬과 수렴속도, 계산량 면에서 성능을 평가한다.

• Bulletin of the Korean Chemical Society
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• 제22권5호
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• pp.467-475
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• 2001

A triblock copolymer based on $poly(\varepsilon-caprolactone)$ (PCL) as the hydrophobic part and poly(ethylene glycol) (PEG) as the hydrophilic portion was synthesized by a ring-opening mechanism of ${\varepsilon}-caprolactone$ with PEG containing a hydroxyl group at bot h ends as an initiator. The synthesized block copolymers of PCL/PEG/PCL (CEC) were confirmed and characterized using various analysis equipment such as 1H NMR, DSC, FT-IR, and WAXD. Core-shell type nanoparticles of CEC triblock copolymers were prepared using a dialysis technique to estimate their potential as a colloidal drug carrier using a hydrophobic drug. From the results of particle size analysis and transmission electron microscopy, the particle size of CEC core-shell type nanoparticles was determined to be about 20-60 nm with a spherical shape. Since CEC block copolymer nanoparticles have a core-shell type micellar structure and small particle size similar to polymeric micelles, CEC block copolymer can self-associate at certain concentrations and the critical association concentration (CAC) was able to be determined by fluorescence probe techniques. The CAC values of the CEC block copolymers were dependent on the PCL block length. In addition, drug loading contents were dependent on the PCL block length: the larger the PCL block length, the higher the drug loading content. Drug release from CEC core-shell type nanoparticles showed an initial burst release for the first 12 hrs followed by pseudo-zero order release kinetics for 2 or 3 days. CEC-2 block copolymer core-shell type nanoparticles were degraded very slowly, suggesting that the drug release kinetics were governed by a diffusion mechanism rather than a degradation mechanism irrelevant to the CEC block copolymer composition.

• Journal of information and communication convergence engineering
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• 제3권1호
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• pp.5-8
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• 2005

Dynamic cipher has the property that the key-size, the number of round, and the plaintext-size are scalable simultaneously. We present the method for designing secure Dynamic cipher against meet-in-the-middle attack and linear cryptanalysis. Also, we show that the differential cryptanalysis to Dynamic cipher is hard. In this paper we propose a new network called Dynamic network for symmetric block ciphers.