• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.519-528
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• 2016

In order to achieve fast computational speed with good visual quality of output video, we propose a frequency domain based new fractal video compression scheme. Normalized cross correlation is used to find the structural self similar domain block for the input range block. To increase the searching speed, cross correlation is implemented in the frequency domain using FFT with one computational operation for all the domain blocks instead of individual block wise calculations. The encoding time is further minimized by applying rotation and reflection DFT properties to the IFFT of zero padded range blocks. The energy of overlap small size domain blocks is pre-computed for the entire reference frame and retaining the energies of the overlapped search window portion of previous adjacent block. Quadtree decompositions are obtained by using domain block motion compensated prediction error as a threshold to control the further partitions of the block. It provides a better level of adaption to the scene contents than fixed block size approach. The result shows that, on average, the proposed method can raise the encoding speed by 48.8 % and 90 % higher than NHEXS and CPM/NCIM algorithms respectively. The compression ratio and PSNR of the proposed method is increased by 15.41 and 0.89 dB higher than that of NHEXS on average. For low bit rate videos, the proposed algorithm achieve the high compression ratio above 120 with more than 31 dB PSNR.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표회 논문집(I)
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• pp.157-160
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• 1998

KS F 4419, which is dealt with the Inter-Locking block, states that water to cement ratio for manufacturing inter-locking block should be less than 25% and in KS F4419, the use of admixture is shown to be reluctant to recommend. In this paper, reinvestigation of some regulations in KS F 4419 are carried out. According to the experimental results, as W/C increases, flexural strength and compressive strength are tended to decrease, whereas they increases within certain range, Flexural strength and compressive strength have higher values in 1:2(W/C=35%), 1:4(W/C=45%) and 1:6(W/C=55%) of mix proportions. Moreover they have rather higher values with the containment of high range AE water-reducing agent. The absorption ratios decrease with the increase of W/C and the containment of high range AE water-reducing agent. Therefore, the regulations on the W/C and admixture in KS F 4419 reguire revision.

• Communications for Statistical Applications and Methods
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• 제24권1호
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• pp.1-13
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• 2017

This manuscript summarized advances in bootstrap methods for long-range dependent time series data. The stationary linear long-memory process is briefly described, which is a target process for bootstrap methodologies on time-domain and frequency-domain in this review. We illustrate time-domain bootstrap under long-range dependence, moving or non-overlapping block bootstraps, and the autoregressive-sieve bootstrap. In particular, block bootstrap methodologies need an adjustment factor for the distribution estimation of the sample mean in contrast to applications to weak dependent time processes. However, the autoregressive-sieve bootstrap does not need any other modification for application to long-memory. The frequency domain bootstrap for Whittle estimation is provided using parametric spectral density estimates because there is no current nonparametric spectral density estimation method using a kernel function for the linear long-range dependent time process.

• 한국정보과학회논문지:시스템및이론
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• 제27권2호
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• pp.117-122
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• 2000

프랙탈 영상 압축은 영상의 일부 영역이 같은 영상의 다른 영역과 거의 유사한 모양을 하고 있다는 자기유사성에 기초하고 있다. 이 압축 방법은 높은 압축률과 빠른 복원력을 제공하지만 매우 긴 압축 시간을 갖는다. 압축 시간을 줄이기 위해 가장 많은 시간이 소요되는 레인지 블록과 도메인 블록간의 비교 탐색 과정을 줄이려는 시도가 꾸준히 이루어져 왔다. 이 연구들은 크게 탐색할 도메인 영역에 제한을 가하는 방법과 도메인 블록의 탐색 순서를 주어진 조건을 만족하는 최초의 도메인을 찾는 방법으로 나누어 볼 수 있다. 그러나 대부분의 프랙탈 영상 압축 기법은 아직도 많은 압축 시간을 필요로 하고 있다. 본 연구에서는 영상 압축 시간을 획기적으로 줄이기 위해 레인지 블록간의 유사성을 이용하여 몇 개의 레인지 플록에 대해서만 도메인 탐색을 시도하는 새로운 방법을 제안한다. 이를 위해 모든 레인지 블록은 각각의 모양을 바탕으로 몇 개의 유사 그룹으로 분류되며, 각 그룹의 대표 블록에 대해서만 도메인 탐색을 실행하게 된다. 또한 이 방법을 다른 프랙탈 영상 압축 기법의 사전 작업으로 활용한다면 더욱 큰 효과를 보게 될 것이다.

• The Korean Journal of Pain
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• 제7권1호
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• pp.84-87
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• 1994

Retrospective analysis, of 1,734 patients treated for nerve block from October 1991 to March 1994. Largest percentage of patients were in the 50 year old range, with a distribution of 44.9% male and 55.1% female. Treatments were for ailments of: Low Back Pain 17.3%, Multiple Contusion 10.5%, and Cancer 10%. Most common nerve block was epidural block 38.6%, followed by stellate ganglion block 38.4%, intercostal block 5.4%, and suprascapular nerve block 5.2%. Nerve block under fluorscopic guide were as follows: facet joint block 34.1%, lumbar sympathetic ganglion block 13.6%, and celiac plexus block 12.9%.

• 전기전자학회논문지
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• 제11권4호
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• pp.219-226
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• 2007

본 논문은 HDR(High Dynamic Range) 영상을 기존의 JPEG 압축 방법을 이용하여 효율적으로 압축할 수 있는 방안을 제안한다. 입력 HDR 영상을 동적 영역 압축(Dynamic range compression)하여 통해 얻어지는 LDR(Low Dynamic Rage) 영상 및 HDR 영상과 LDR영상의 비율을 나타내는 비율 (Ratio) 영상으로 분리한다. LDR 영상은 하위 호환성을 유지하기 위해 기존의 JPEG 알고리듬을 이용하여 압축하며, 비율 영상은 각 블록별로 HVS(Human Visual System)이 인지하는 차이를 모델링 한 비용함수를 최소화 하도록 압축한다. 따라서 제안하는 알고리듬을 적용하면 동일한 조건에서 압축된 결과 영상에 왜곡이 적게 발생하게 되며, 컴퓨터 모의실험을 통해 그 유효성을 확인한다.

• 전자공학회논문지B
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• 제33B권11호
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• pp.62-71
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• 1996

In this paper we propose a method that improves PSNR at low bit rate and reduces computational complexity in fractal image coding based on discrete wavelet transform. The proposed method, which uses significant coefficient tree, improves PSNR of the reconstructed image and reduces computational comlexity of mapping domain block onto range block by matching only the significant coefficients of range block to coefficients of domain block. Also, the proposed method reduces error propagation form lower resolution subbands to higher resolution subbands by correcting error of lower resolution subbands. Some experimental results confirm that the proposed method reduces encoding and decoding time significantly and has fine reconstructed images having no blocking effect and clear edges at low bit rate.

• The Korean Journal of Pain
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• 제8권1호
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• pp.60-64
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• 1995

Stellate ganglion block is a selective sympathetic blockade affecting the head and neck, and the upper extemity. It is an important method which has been used most frequently in neuro-pain clinic due to its wide range of indications. The authors attermpted to define the minimal volume of local anesthetic which need for successful stellate ganglion block by using 1% mepivacaine HCl mixed with dye. In 40 heathy volunteers, two different volumes, 3 ml in the group 1 (n=20) and 4 ml in the group 2 (n=20), were injected by an anterior paratracheal technique at the sixth cervical vertebral level. We compared the degree in sympathetic blockade by clinical sings and symptoms and also checked the spread range of dye by plain X-ray. With seven criteria for an effective block. mean score was 5.7 in group 2, while 3.4 in group 1. These results suggest that 4 ml of local anesthetic are adequate for a successful stellate ganglion block.

• 대한치과의사협회지
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• 제50권6호
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• pp.329-338
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• 2012

Introduction: The purpose of this study is to evaluate the clinical results of vertical alveolar ridge augmentation using autogenous block bone graft, especially resorption rate, and outcomes of dental implants placed in the grafted site. Patients and Methods: Medical records and radiographs were reviewed. Twenty-seven patients who have been received the autogenous block bone graft which harvested from chin, ramus, and ilium, and the implant installation on 31 areas(22 maxillas and 9 mandibles) were included. Eight implants were installed simultaneously at the time of bone graft in 4 patients, and 65 implants were installed after 4.9 months(range 2~18 months) of autogenous block bone graft in 23 patients. The resorption amount and rate of augmented bone, and the success and survival rates implants were evaluated. Results: Mean height of the augmented block bone was $5.9{\pm}2.3mm$(range from 2.5 to 13.0 mm). Mean follow-up period after block bone graft was 30.4 months(range from 16 to 55 months). Mean resorption of the augmented block bone was $2.0{\pm}1.5mm$ (range from 0.5 to 7.24 mm). The success and survival rates of the implants were 78.1 % and 98.6%, respectively. Conclusion: This study indicates that the autogenous block bone graft is a useful and stable method for alveolar ridge augmentation for dental implant. And more augmentation is needed to compensate the resorption of the grafted bone.

• 대한족부족관절학회지
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• 제8권1호
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• pp.101-106
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• 2004

Purpose: To determine the efficacy of the SDBBA (Subtalar distraction bone block arthrodesis) procedure on patients with late complication of intra-articular calcaneal fractures including subtalar joint arthritis and anterior ankle impingement syndrome. Materials and Methods: Five cases in which the SDBBA procedure was implemented were followed for more than one year. All five patients were male with an average age of 56. Clinically, the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the pain score were assessed. Radiographically, the talocalcaneal height and the talar inclination angle were determined. Results: All five patients achieved subtalar joint fusion. The average pre-operative AOFAS score was 22.8 scores (range, 8-32 scores). At last follow-up, these scores improved to an average of 72.4 scores (range, 64-82 scores). The average pre-operative pain score was 8.2 scores (range, 7-10 scores). At last follow-up, these scores improved to an average of 13.2 (range, 12-15 scores). The average pre-operative talocalcaneal height was 72.8 mm (range, 70-77 mm), average post-operative talocalcaneal height improved to 79.8 mm (range, 78-84 mm). At final follow-up, these measurement was slightly decreased to average 78.6 mm (range, 74-83 mm). The average pre-operative talar inclination angle was 13.2 degrees (range, 12-15 degrees), average post-operative talar inclination angle improvedto 19.2 degrees (range, 15-24 degrees). At final follow-up, these measurement was slightly decreased to average 18.6 degrees (range, 12-24 degrees). Four patients achieved successful outcomes. One patient developed a wound infection with subsequent sural neuropathy as well as collapse of the bone graft. Conclusion: This study shows that the SDBBA procedure successfully restores the talocalcaneal height and tibio-talar relationship. This procedure is useful in surgically managed patients with talo-calcaneal height loss and anterior ankle impingement syndrome due to the late complications of calcaneal intra-articular fractures.