• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.85-88
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• 2019

In this paper, we propose a technique for spatially encrypting confidential data into R, G, B planes of color image and extracting spatially encrypted confidential data. The effectiveness of the proposed technique is verified by mathematically analyzing the quality of the stego-image generated using the proposed technique. The proposed technique can hide confidential data securely into cover image by spatially encrypting the confidential data, and can extract confidential data from the stego-image. The quality of the stego-image created by applying the proposed technique is very good. The average value of the quality of the stego-image is 51.14 dB. Therefore, it is not visually recognizable whether the confidential data is hidden in the stego-image. The proposed technique can be widely used for military and intellectual property protection.

• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.126-130
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• 2004

Purpose: In this study, we tried to develop the technique of osteotomy for hallux valgus. The new modified technique of osteotomy was accomplished with even more greater stability, accurate correction of the deformity and more effective than 'chevron' osteotomy in terms of correction of the deformity. Materials and Methods: Between March 1998 and December 2001, 55 cases of new modified osteotomy for hallux valgus were performed for 39 patients, 16 of whom underwent operation of both feet. Operations were made for 34 women and 5 men whose average age was 46 years old (range, $20{\sim}71$ years). Average follow up period was three years (range, $2{\sim}5$ years), and during the follow up, the patients underwent physical examination and assessment with use of the American Orthpaedic Foot and Ankle Society's hallux-metatarso-phalangealinterphalangeal scale and standard foot radiographic measurements. Results: 37 patients (53 cases) out of 39 patients (55 cases) had no pain, good cosmesis, and all of the patients were satisfied with the results of the operation. Two had occasional mild discomfort. The average score according to the hallux-metatarso-phallangeal-interphalangeal scale was 93.2 points (range, $78{\sim}100$ points). The average preoperative intermetatarsal angle was $14.4^{\circ}$, which was decreased to $7.9^{\circ}$ after the osteotomy with an average correction of $6.5^{\circ}$ and The average preoperative hallux valgus angle was $34.1^{\circ}$, which was decreased to $11.1^{\circ}$ after the osteotomy with an average correction of $23^{\circ}$. This new modified technique would prevent the angulation or shortening at the osteotomy site and it was also even more stable at osteotomy site, and could do even more effective and accurate correction of the deformity than conventional Chevron osteotomy. Conclusion: New modified chevron osteotomy for the treatment of symptomatic hallux valgus was done in 55 cases, and the results were satisfactory in all cases. This method was more stable at the osteotomy site than conventional Chevron osteotomy and was also possible to do more accurate and more effective correction of the deformity. It was also easy to control the distal fragment of first metatarsal bone.

• Journal of KIISE
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• v.44 no.11
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• pp.1130-1137
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• 2017

The multi-leveling technique that stores multiple bits in a single memory cell has significantly improved the density of NAND flash memory along with shrinking processes. However, because of the side effects of the multi-leveling technique, the average write performance of MLC NAND flash memory is degraded more than twice that of SLC NAND flash memory. In this paper, we introduce existing cross-layer optimization techniques proposed to improve the performance of MLC NAND flash-based storages, and propose a new integration technique that overcomes the limitations of existing techniques by exploiting their complementarity. By fully exploiting the performance asymmetry in MLC NAND flash devices at the flash translation layer, the proposed technique can handle many write requests with the performance of SLC NAND flash devices, thus significantly improving the performance of NAND flash-based storages. Experimental results show that the proposed technique improves performance 39% on average over individual techniques.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.113-120
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• 2023

Smart farms are steadily increasing in research to minimize labor, energy, and quantity put into crops as IoT technology and artificial intelligence technology are combined. However, research on efficiently managing crop growth information in smart farms has been insufficient to date. In this paper, we propose a management technique that can efficiently monitor crop growth information by applying autonomous sensors to smart farms. The proposed technique focuses on collecting crop growth information through autonomous sensors and then recycling the growth information to crop cultivation. In particular, the proposed technique allocates crop growth information to one slot and then weights each crop to perform load balancing, minimizing interference between crop growth information. In addition, when processing crop growth information in four stages (sensing detection stage, sensing transmission stage, application processing stage, data management stage, etc.), the proposed technique computerizes important crop management points in real time, so an immediate warning system works outside of the management criteria. As a result of the performance evaluation, the accuracy of the autonomous sensor was improved by 22.9% on average compared to the existing technique, and the efficiency was improved by 16.4% on average compared to the existing technique.

• Journal of Korean Foot and Ankle Society
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• v.28 no.1
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• pp.15-20
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• 2024

Purpose: Achilles tendon rupture is a frequently encountered ankle pathology associated with a substantial burden of intense pain and functional deficits. Chronic Achilles tendon ruptures with considerable defects pose intricate repair challenges that are often marred by complications such as re-rupture and persistent pain. Various treatment methods, including allograft transplantation, have been proposed, but the literature on this technique is limited. In this study, we propose a surgical approach utilizing allotendon transplantation and a calcaneal tunneling technique and provide clinical evaluation details. Materials and Methods: Fifteen patients with chronic Achilles tendon ruptures treated with allotendon between 2020 and 2022 were included in the study. Patients were evaluated at 1, 3, and 6 months postoperatively using Visual Analog Scale (VAS) scores and Achilles Tendon Total Rupture Scores (ATRSs). Complications were assessed postoperatively. Results: The average VAS score was 7 before surgery, 7.3 immediately after surgery, and 4.3 at 1 month, 2.5 at 3 months, and 1.3 at 6 months after surgery. Because the sample was limited to 15 individuals and distributions were non-normal, the analysis was conducted using the non-parametric Wilcoxon's signed-rank test, and statistical significance was accepted for p-values<0.05. Results showed a significant improvement in ATRS and VAS scores versus preoperative and immediate postoperative values. VAS scores showed a decreasing trend after surgery, whereas average ATRS scores increased from 14 before surgery, 33.8 at 1 month, 82.7 at 3 months, and 93.9 at 6 months. Conclusion: This study suggests that allograft transplantation using the described calcaneal tunnel technique provides an effective treatment for chronic Achilles tendon ruptures. However, extensive research and long-term clinical trials are required to validate and better understand the technique's efficacy.

• Journal of Periodontal and Implant Science
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• v.38 no.3
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• pp.483-492
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• 2008

Purpose: The purpose of this study was to compare clinical effect of the Langer & Langer technique, the modified Langer & Langer technique and Bruno technique. Material and Methods: 30 patients who have gingiva recession(Miller class I or class II) were carried root coverage. Langer & Langer technique(14 patients/32 tooth), modified Langer & Langer technique(5 patients/10 tooth) and Bruno technique(11 patients/18 tooth) was carried. At baseline and average 3 months after operation, it was estimated clinical index(Pocket depth, gingiva recession, clinical attachment level, keratinized gingiva, scar tissue, root coverage rate) by Williams style probe. Result: Root coverage rate is indicated Langer & Langer technique(8S%), Modified Langer & Langer technique(86%) and Bruno technique(90%). Conclusion: All three of the procedures were effective in gingival recession and improved clinical parameters.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.154-154
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• 2021

Since the development of Bubble Image Velocimetry (BIV) technique as the complementary technique of Particle Image Velocimetry (PIV), the application of digital imaging technique in the field of hydraulic and coastal engineering increased rapidly. BIV works very well in multi-phase flow (air-water) flows where the PIV technique doesn't. However, the velocity field obtained from BIV technique often resulted in a velocity vector on the outside of the flow (false velocity) since the Field of View (FOV) usually not only cover the air-water flow but also the area outside the flow. In this study, a simple technique of post processing velocity field was developed. This technique works based on the average of the pixel value in the interrogation area. An image of multi-phase flow of wave overtopping was obtained through physical experiment using BIV technique. The velocity calculation was performed based on the similar method in PIV. A velocity masking technique developed in this study then applied to remove the false velocity vector. Result from non-masking, manually removed and auto removed false velocity vector were presented. The masking technique show a similar result as manually removed velocity vector. This method could apply in a large number of velocity field which is could increase the velocity map post-processing time.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.38-43
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• 2013

In order to design a wave energy generating system, a 6-DOF analysis technique is applied to CFD analysis on of a floating body and the behavior is interpreted according to the nature of the incoming waves. A spring constant is adopted to control the motion of multi floating bodies and to calculate the total average power absorption. Three cases of different wavelengths namely 20D, 30D and 40D have been modeled to analyze the total average power absorption. The average power absorption not only varies with the position of the floating body but also varies with wavelength. From the results obtained, it is concluded that the maximum total average power absorption is 9W approximately in wavelength 30D and the minimum total average power absorption is 4.3W approximately in wavelength 40D.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.534-539
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• 2001

An experimental investigation of heat transfer characteristics on confined jet impinging plate using multiple slot jets has been performed. The effects of jet Reynolds numbers(Re=2000, 3950, 5900, 7900), dimensionlesss slot-to-plate distances(H/B=2, 4, 6, 8) and jet-to-jet distances(S=16B, 20B, 24B, 30B) on the local and average heat transfer coefficients have been examined. To clarify local heat transfer characteristics, naphthalene sublimation technique were used. From the experimental results, it was found that the local and average heat transfer rates increase with increasing jet Reynolds number. Measurements of local heat transfer coefficients produced by multiple of slot jets have given an indication of the nature of the interaction between jets and of the uniformity of heat transfer obtainable with various arrangements. At S/B=20, Re=7900 and H/B=6, maximum average Nusselt number is obtained.

• ETRI Journal
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• v.30 no.3
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• pp.412-420
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• 2008

A new scan partition architecture to reduce both the average and peak power dissipation during scan testing is proposed for low-power embedded systems. In scan-based testing, due to the extremely high switching activity during the scan shift operation, the power consumption increases considerably. In addition, the reduced correlation between consecutive test patterns may increase the power consumed during the capture cycle. In the proposed architecture, only a subset of scan cells is loaded with test stimulus and captured with test responses by freezing the remaining scan cells according to the spectrum of unspecified bits in the test cubes. To optimize the proposed process, a novel graph-based heuristic to partition the scan chain into several segments and a technique to increase the number of don't cares in the given test set have been developed. Experimental results on large ISCAS89 benchmark circuits show that the proposed technique, compared to the traditional full scan scheme, can reduce both the average switching activities and the average peak switching activities by 92.37% and 41.21%, respectively.