• Title/Summary/Keyword: block segment

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Correct Implementation of Sub-warp Parallel Prefix Operations based on GPU Hardware Architecture (GPU 하드웨어 아키텍처 기반 sub-warp 단위 병렬 프리픽스(prefix) 연산의 정확한 구현)

  • Park, Taejung
    • Journal of Digital Contents Society
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    • v.18 no.3
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    • pp.613-619
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    • 2017
  • This paper presents a CUDA (Compute Unified Device Architecture) code to achieve correct GPU parallel segmented prefix operation results with less than 32 segment length for large data arrays. Mark Harris and Michael Garland had published CUDA code to address the tasks. This paper shows that their code does not generate correct results when the local segment length is less than 32, discusses the cause of the problem, and presents a CUDA code that generates correct results. The segmented parallel prefix operation presented in this paper can be applied as a building block to various large parallel processing algorithms including the k-nearest neighbor search problems.

Image Dehazing Enhancement Algorithm Based on Mean Guided Filtering

  • Weimin Zhou
    • Journal of Information Processing Systems
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    • v.19 no.4
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    • pp.417-426
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    • 2023
  • To improve the effect of image restoration and solve the image detail loss, an image dehazing enhancement algorithm based on mean guided filtering is proposed. The superpixel calculation method is used to pre-segment the original foggy image to obtain different sub-regions. The Ncut algorithm is used to segment the original image, and it outputs the segmented image until there is no more region merging in the image. By means of the mean-guided filtering method, the minimum value is selected as the value of the current pixel point in the local small block of the dark image, and the dark primary color image is obtained, and its transmittance is calculated to obtain the image edge detection result. According to the prior law of dark channel, a classic image dehazing enhancement model is established, and the model is combined with a median filter with low computational complexity to denoise the image in real time and maintain the jump of the mutation area to achieve image dehazing enhancement. The experimental results show that the image dehazing and enhancement effect of the proposed algorithm has obvious advantages, can retain a large amount of image detail information, and the values of information entropy, peak signal-to-noise ratio, and structural similarity are high. The research innovatively combines a variety of methods to achieve image dehazing and improve the quality effect. Through segmentation, filtering, denoising and other operations, the image quality is effectively improved, which provides an important reference for the improvement of image processing technology.

An Embedded FAST Hardware Accelerator for Image Feature Detection (영상 특징 추출을 위한 내장형 FAST 하드웨어 가속기)

  • Kim, Taek-Kyu
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.2
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    • pp.28-34
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    • 2012
  • Various feature extraction algorithms are widely applied to real-time image processing applications for extracting significant features from images. Feature extraction algorithms are mostly combined with image processing algorithms mostly for image tracking and recognition. Feature extraction function is used to supply feature information to the other image processing algorithms and it is mainly implemented in a preprocessing stage. Nowadays, image processing applications are faced with embedded system implementation for a real-time processing. In order to satisfy this requirement, it is necessary to reduce execution time so as to improve the performance. Reducing the time for executing a feature extraction function dose not only extend the execution time for the other image processing algorithms, but it also helps satisfy a real-time requirement. This paper explains FAST (Feature from Accelerated Segment Test algorithm) of E. Rosten and presents FPGA-based embedded hardware accelerator architecture. The proposed acceleration scheme can be implemented by using approximately 2,217 Flip Flops, 5,034 LUTs, 2,833 Slices, and 18 Block RAMs in the Xilinx Vertex IV FPGA. In the Modelsim - based simulation result, the proposed hardware accelerator takes 3.06 ms to extract 954 features from a image with $640{\times}480$ pixels and this result shows the cost effectiveness of the propose scheme.

Fully Automatic Heart Segmentation Model Analysis Using Residual Multi-Dilated Recurrent Convolutional U-Net (Residual Multi-Dilated Recurrent Convolutional U-Net을 이용한 전자동 심장 분할 모델 분석)

  • Lim, Sang Heon;Lee, Myung Suk
    • KIPS Transactions on Computer and Communication Systems
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    • v.9 no.2
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    • pp.37-44
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    • 2020
  • In this paper, we proposed that a fully automatic multi-class whole heart segmentation algorithm using deep learning. The proposed method is based on U-Net architecture which consist of recurrent convolutional block, residual multi-dilated convolutional block. The evaluation was accomplished by comparing automated analysis results of the test dataset to the manual assessment. We obtained the average DSC of 96.88%, precision of 95.60%, and recall of 97.00% with CT images. We were able to observe and analyze after visualizing segmented images using three-dimensional volume rendering method. Our experiment results show that proposed method effectively performed to segment in various heart structures. We expected that our method can help doctors and radiologist to make image reading and clinical decision.

Relaxant Effect of 4-Aminopyridine on the Mesenteric Artery of Rat

  • Kim, Se-Hoon;Lee, Tae-Im
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.6
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    • pp.463-469
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    • 2000
  • It has been well known that 4-aminopyridine (4-AP) has an excitatory effect on vascular smooth muscle due to causing membrane depolarization by blocking $K^+-channel$. However, we observed that 4-AP had an inhibitory effect on the mesenteric artery of rat. Therefore, we investigated the mechanism of 4-AP-induced vasorelaxation. The mesenteric arcuate artery and its branches were isolated and cut into ring. The ring segment was immersed in HEPES-buffered solution and its isometric tension was measured. 4-AP $(0.1{\sim}10\;mM)$ induced a concentration-dependent relaxation, which was unaffected by NO synthase inhibitor, $N^G-nitro-L-arginine$ methylester $(100\;{\mu}M)$ or soluble guanylate cyclase inhibitor, methylene blue $(100\;{\mu}M).$ Glibenclamide $(100\;{\mu}M)$, ATP-sensitive $K^+$ channel blocker, did not exert any effect on the 4-AP-induced vasorelaxation. 4-AP relaxed the sustained contraction induced by 100 mM $K^+$ or $Ca^{2+}$ ionophore, A23187 $(100\;{\mu}M)$ in a dose-dependent manner. In addition, 4-AP significantly decreased the phasic contractile response to norepinephrine in the absence of extracellular $Ca^{2+}$. However, 4-AP did not block the $^{45}Ca$ influx of rat aorta. From the above results, we suggest that 4-AP may not block the $Ca^{2+}$ influx through $Ca^{2+}-channel,$ but act as a nonspecific vasorelaxant in arterial smooth muscle.

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Multiple Texture Image Recognition with Unsupervised Block-based Clustering (비교사 블록-기반 군집에 의한 다중 텍스쳐 영상 인식)

  • Lee, Woo-Beom;Kim, Wook-Hyun
    • The KIPS Transactions:PartB
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    • v.9B no.3
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    • pp.327-336
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    • 2002
  • Texture analysis is an important technique in many image understanding areas, such as perception of surface, object, shape and depth. But the previous works are intend to the issue of only texture segment, that is not capable of acquiring recognition information. No unsupervised method is basased on the recognition of texture in image. we propose a novel approach for efficient texture image analysis that uses unsupervised learning schemes for the texture recognition. The self-organization neural network for multiple texture image identification is based on block-based clustering and merging. The texture features used are the angle and magnitude in orientation-field that might be different from the sample textures. In order to show the performance of the proposed system, After we have attempted to build a various texture images. The final segmentation is achieved by using efficient edge detection algorithm applying to block-based dilation. The experimental results show that the performance of the system Is very successful.

Herpes Zoster Infection Involved in Cervical and Thoracic Spinal Segment Bilaterally (경부 및 흉부신경근에 동시에 발생한 대상포진 -증례 보고-)

  • Han, Kyung-Ream;Kwak, No-Kil;Kim, Soo-Mi;Min, Kyung-Shin;Kim, Chan;Kim, Seong-Mo
    • The Korean Journal of Pain
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    • v.12 no.1
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    • pp.144-147
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    • 1999
  • A 72-year-old female patient was presented complaining of unbearable abdominal pain in the upper left quadrant at our hospital. Two weeks earlier she had developed a vesicular eruption on the right C3 dermatome and 1 week earlier she had experienced a vesicular eruption on the left T11 dermatome. Her medical history was unremarkable. She had suffered from severe abdominal pain in the upper left quadrant for 10 days and the mild pain in the right shoulder region for 20 days. The pain in the upper left quadrant had increased and was unresponsive to drugs prescribed by the local clinic. And we performed T11 root block with 0.5% lidocaine 5 ml and dexametasone 5 mg, and thoracic epidural blockade on 1st hospital day under diagnosis of herpes zoster infection. Her VAS were improved from 10 to 2 on 2nd hospital day. We performed thoracic epidural blockade with 0.5% lidocaine 6 ml. Her VAS were changed from 2 to 7 and so then we performed the thoracic epidural blockade with 0.5% lidocaine 5 ml and triamcinolone 40 mg on 3rd hospital day. On 4th hospital day, her VAS were from 7 to 1. After 4 month of our managements she was tolerable without any medications.

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Preparation of Polyolefin Based Segmented Copolymers Through Controlled Radical Polymerization Technique (조절 라디칼 중합법에 의한 폴리올레핀 기반 분절 공중합체의 제조)

  • Hong, Sung-Chul;Lee, Seong-Hoon;Cho, Hyun-Chul
    • Elastomers and Composites
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    • v.44 no.3
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    • pp.209-221
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    • 2009
  • Polyolefins are important commodity polymers with the largest volume of business owing to their outstanding combination of cost performance and excellent physical properties. However, the lack of functional groups often has limited their end uses, such as compatibilizer, modifier and adhesive, where the interaction with other materials is especially important. The incorporation of functional groups as polymer segments to afford block or graft polyolefin copolymers has been extensively investigated in the context of the functional polyolefin hybrids. Living polymerization processes have been considered to be an efficient method to prepare the polyolefin hybrids with precisely controlled architecture and compositions. Among the living polymerization techniques, controlled/"living" radical polymerization (CRP) methods are very effective not only because of the controllability of polymerization but also because of the versatility of monomers and polymerization conditions. In this review paper, progresses on the preparations of polyolefin graft or block copolymers through CRP techniques are summarized. The commodity polymers such as polyisobutylene, polyethylene and polypropylene are combined with polar segments such as polyacrylate, polymethacrylate, polystyrene to yield functionalized polyolefins.

Anesthetic Experience for Trans-Sphenoidal Surgery of Pituitary Adenoma on a Patient with Brugada Syndrome - A Case Report - (Brugada 증후군 환자의 경접형동 선종절제술을 위한 마취 경험)

  • Heo, Min-Jung;Kim, Sae-Yeon
    • Journal of Yeungnam Medical Science
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    • v.26 no.2
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    • pp.148-155
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    • 2009
  • Brugada syndrome is characterized by an ECG pattern of right bundle branch block and ST segment elevation in the right precordial leads ($V_1-V_3$) without structural heart disease. It is also characterized by sudden cardiac death that's caused by ventricular fibrillation. This is a familial syndrome with an autosomal dominant inheritance pattern and it may be considerably more common in Southeast Asia. Many factors during anesthesia can precipitate malignant dysrrhythmia in these patients, so careful choice of anesthetics is required. We experienced a case of Brugada syndrome in a 59-year-old male patient who was under general anesthesia for trans-sphenoidal surgery to treat a pituitary adenoma, and the patient was diagnosed as having Brugada syndrome without any untoward cardiovascular events.

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Development of a korean Text Recognition System (한글 문서 인식 시스템 개발 연구)

  • 고견;이일병
    • Korean Journal of Cognitive Science
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    • v.1 no.1
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    • pp.77-102
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    • 1989
  • This paper reports on the development of a recognition system for Korean character,numbers and punctuation marks by syntactic approach after extracting a character or punctuation mark from a page of text.First,using the projection profile(Masudaet.al.1985,Pavlidin 1981)method, we segment a page into different regions of column or row major and then extracts lines of characters from it.Considering the height,width and connectivity of character block,we proceed to extract syllables from the extracted lines.Basically we distinguish syables into six types of formal pattern(남궁재찬 1982,이주근등 1981)following the research of lee and others,and the punctuation marks and numbers into two kinds of formal patterns,and discriminate the surface structure of the extracted syllables.By Index-Removal algorithm,we subdivide them into 44 kinds of basic korean subpattern and special characters (numbers,punctuation marks)and recognize them by syntactic method(이주근등 1981.)