• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1228-1231
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• 2002

Digital image watermarking scheme using adaptive block division is proposed. To increase the perceptual invisibility, the image is divided into blocks by local properties and the human visual system (HVS), then the significant blocks are selected in the divided blocks. The significant coefficient is determined by Weber's law in these blocks. To increase the robustness, low frequency domains of the discrete cosine transform (DCT) and the discrete wavelet transform (DWT) are used. The watermark is embedded into the selected significant blocks of the DCT's and DWT's low frequency domains with adaptive watermark strengths. The watermark strength is determined by the variance and the local properties of the significant block. The experimental results prove that the proposed scheme has a good robustness against several image processing operations (e.g. median filtering, cropping, scaling, JPEG, JPEG2000, etc.) without significant degradation of the watermarked image.

• Korean Journal of Adult Nursing
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• v.29 no.2
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• pp.143-153
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• 2017

Purpose: Purpose of the study was to identify the effect of the Comprehensive Education Program (CEP) on intra-procedure anxiety, post-procedure uncertainty and athletic performance of back strengthening of patients undergo spinal nerve block (SNB). Methods: The participants (experimental group=33, control group=33) were recruited from a university hospital in G metropolitan city. Data were collected from July to November 2015. The experimental group was individually provided with a booklet/motion picture about the SNB and back strengthening exercise training before the SNB. This group also received a leaflet about back strengthening exercise post SNB. The Anxiety-Visual Analog Scale (A-VAS), the Mishel adapted uncertainty scale and newly created knowledge scale/athletic performance checklist were utilized as our study tools. Results: Intra-procedure anxiety score (F=25.70, p<.001), post-procedure uncertainty score (F=82.56, p<.001), post-procedure knowledge score (F=14.63, p<.001) and athletic performance rate of back strengthening (p=.003) of the experimental group showed statistically significant differences in comparison with the control group. Conclusion: This CEP is a cost and time-effective intervention for patients who undergo spinal injections, so it should be actively utilized as an educational management strategy in outpatient.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6043-6062
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• 2019

Low-rank matrix decomposition has shown its capability in many applications such as image in-painting, de-noising, background reconstruction and defect detection etc. In this paper, we consider the texture background of rail track images and the sparse foreground of the defects to construct a low-rank matrix decomposition model with block sparsity for defect inspection of rail tracks, which jointly minimizes the nuclear norm and the 2-1 norm. Similar to ADM, an alternative method is proposed in this study to solve the optimization problem. After image decomposition, the defect areas in the resulting low-rank image will form dark stripes that horizontally cross the entire image, indicating the preciselocations of the defects. Finally, a two-stage defect extraction method is proposed to locate the defect areas. The experimental results of the two datasets show that our algorithm achieved better performance compared with other methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2326-2345
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• 2016

For the compression of color images, a common bitmap usually is generated to replace the three individual bitmaps that originate from block truncation coding (BTC) of the R, G and B channels. However, common bitmaps generated by some traditional schemes are not the best possible because they do not consider the minimized distortion of the entire color image. In this paper, we propose a near-optimized common bitmap scheme for BTC using Binary Ant Colony Optimization (BACO), producing a BACO-BTC scheme. First, the color image is compressed by the BTC algorithm to get three individual bitmaps, and three pairs of quantization values for the R, G, and B channels. Second, a near-optimized common bitmap is generated with minimized distortion of the entire color image based on the idea of BACO. Finally, the color image is reconstructed easily by the corresponding quantization values according to the common bitmap. The experimental results confirmed that reconstructed image of the proposed scheme has better visual quality and less computational complexity than the referenced schemes.

• The Journal of Natural Sciences
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• v.7
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• pp.67-73
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• 1995

In this paper, a new texture segmentation-based image coding technique which performs segmentation based on properties of the human visual system (HVS) is presented. This method solves the problems of a segmentation-based image coding technique with constant segments by proposing a methodology for segmenting an image into texturally homogeneous regions with respect to the degree of roughness as perceived by the HVS. The segmentation is accomplished by thresholding the fractal dimension so that textural regions are classified into three texture classes; perceived constant intensity, smooth texture, and rough texture. It is very important to determine the proper block size for estimating the fractal dimension. Good quality reconstructed images are obtained with about 0.1 to 0.25 bit per pixel (bpp) for many different types of imagery.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.64-68
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• 2005

Migraine is a disabling headache that can occur with or without aura. We present here a case of migraine that was effectively managed by a series of cervical epidural blocks. A 41-year-old woman who had suffered from severe headache on her left temporal area for 12 years visited our pain clinic. Her 11-point numeric pain rating scale was 10 out of 10 at the first visit and the symptoms were associated with homonymous visual disturbances, paresthesia on the left face, shoulder and arm, and general weakness. For the first 5 years after the headaches began, her headache was relatively well controlled by acetaminophen; after then, the acetaminophen wasn't effective. After wandering from this hospital to the next one in search of relief, she managed to visit our pain clinic. We tried several blocks including cervical epidural block, and she was continuously medicated with sumatriptan. Her headache was gradually relieved. Now, her 11-point numeric rating scale is 1-2 out of 10 at the most during her headache attacks.

• The Korean Journal of Pain
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• v.24 no.3
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• pp.158-163
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• 2011

Background: Although a brachial plexus block can be used to provide anesthesia and analgesia for upper extremity surgery, its effects using $MgSO_4$ on postoperative pain management have not been reported. The aim of this study was to evaluate brachial plexus block using $MgSO_4$ on postoperative analgesia. Methods: Thirty-eight patients who were scheduled to undergo upper extremity surgery were randomly allocated into two groups: patients receiving axillary brachial plexus block with 0.2% ropivacaine 20 ml and normal saline 2 ml (group S) or 0.2% ropivacaine 20 ml and $MgSO_4$ 200 mg (group M). Before extubation, the blocks were done and patient controlled analgesia was started, and then, the patients were transported to a postanesthetic care unit. The postoperative visual analogue scale (VAS), opioid consumption, and side effects were recorded. Results: The two groups were similar regarding the demographic variables and the duration of the surgery. No differences in VAS scores were observed between the two groups. There was no statistically significant difference in opioid consumption between the two groups. Nausea was observed in three patients for each group. Conclusions: Axillary brachial plexus block using $MgSO_4$ did not reduce the level of postoperative pain and opioid consumption.

• The korean journal of orthodontics
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• v.48 no.1
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• pp.11-22
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• 2018

Objective: The aim of this study was to determine cephalometric factors that help predict favorable soft-tissue profile outcomes following treatment with the Class II Twin-block appliance. Methods: Pre- and post-treatment lateral cephalograms of 45 patients treated with the Class II Twin-block appliance were retrospectively analyzed. Profile silhouettes were drawn from the cephalograms and evaluated by three orthodontists in order to determine the extent of improvement. Samples were divided into a favorable group (upper 30% of visual analogue scale [VAS] scores, n = 14) and an unfavorable group (lower 30% of VAS scores, n = 14). Skeletal and soft-tissue measurements were performed on the cephalograms and an intergroup comparison was conducted. Results: An independent t-test revealed that the following pre-treatment values were lower in the favorable group compared to the unfavorable group: lower incisor to mandibular plane angle, lower incisor to pogonion distance, point A-nasion-point B angle, sella-nasion line (SN) to maxillary plane angle, SN to mandibular plane angle, gonial angle, and symphysis inclination. The favorable group had a larger incisor inclination to occlusal plane. Moreover, the favorable group showed larger post-treatment changes in gonial angle, B point projection, and pogonion projection than did the unfavorable group. Conclusions: Class II malocclusion patients with a low divergent skeletal pattern and reduced lower incisor protrusions are likely to show more improvement in soft-tissue profile outcomes following Class II Twin-block treatment.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.47-54
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• 1998

With the increasing popularity of the use of large-volume image database in various application, it becomes imperative to build an efficient and fast retrieval system to browse through the entire database. We present a new method for a content-based image retrieval by using a variable block size and block matching algorithm. Proposed approach is reflecting image features that exploit visual cues such as color and space allocation of image and is getting the fast retrieval time by automatical convergence of retrieval times which adapt to wanting similarity value. We have implemented this technique and tested it for a database of approximately 150 images. The test shows that a 1.9 times fast retrieval time compare to J & V algorithm at the image retrieval efficiency 0.65 and that a 1.83 times fast retrieval time compare to predefined fixed block size.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.21-26
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• 1999

Background: Preoperative blocking of surgical nociceptive inputs may prevent sensitization of central nervous system (CNS) and reduce postoperative pain. The stress responses to surgical trauma consist of increase in catabolic hormones and decrease in anabolic hormones. We studied whether preoperative low dose epidural bupivacaine and morphine could affect postoperative pain, changes plasma cortisol, and serum glucose. Methods: Thirty patients undergoing total abdominal hysterectomy were randomly assigned to one of three groups. General anesthesia was induced in all patients and after that, epidural blocks were done except the control group (n=10) patients. Preoperative block group (n=10) received 0.5% bupivacaine 50 mg and morphine 2 mg epidurally as a bolus before operation and followed by 0.1% bupivacaine $5\;mghr^{-1}$ and morphine $0.2\;mghr^{-1}$ for 10 hours. Postoperative block group (n=10) received the same doses of bupivacaine and morphine under the same method postoperatively. Postoperative pain relief was provided with i.v. fentanyl through Patient-Controlled-Analgesia Pump. Postoperative pain by visual analogue scores (VAS), analgesic requirement (first requirement time, total amounts used), side effects, plasma cortisol level and serum glucose level were compared. Results: Until postoperative 6 hrs, VAS of control group was higher than those of the epidural groups. No difference was observed in VAS between the two epidural groups. First analgesics requirement time and total amounts of used analgesics were not different between the two epidural groups, but first analgesic requirement time of preoperative block group was significantly prolonged compared with control group. Plasma cortisol and serum glucose levels were not different among groups. Conclusions: Low dose preoperative epidural bupivacaine and morphine could not reduce postoperative pain, plasma cortisol level and serum glucose level compared with postoperative block group.