• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.321-326
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• 2019

Image denoising methods based on block matching are founded on the experimental observations that neighboring patches or blocks in images retain similar features with each other, and have been proved to show superior performance in denoising different kinds of noise. The methods, however, take into account only neighboring blocks in searching for similar blocks, and ignore the characteristic features of the reference block itself. Consequently, denoising performance is negatively affected when outliers of the Gaussian distribution are included in the reference block which is to be denoised. In this paper, we propose an expanded block matching method in which noisy images are first decomposed into a number of bit-planes, then the range of true signals are estimated based on the distribution of pixels on the bit-planes, and finally outliers are replaced by the neighboring pixels belonging to the estimated range. In this way, the advantages of the conventional Gaussian filter can be added to the blocking matching method. We tested the proposed method through extensive experiments with well known test-bed images, and observed that performance gain can be achieved by the proposed method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.315-324
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• 2022

The conventional LESS (LEast-Squares Solution) is calculated under the assumption that there is no errors in independent variables. However, the coordinates of a point, either from traditional ground surveying such as slant distances, horizontal and/or vertical angles, or GNSS (Global Navigation Satellite System) positioning, cannot be determined independently (and the components are correlated each other). Therefore, the TLS (Total Least Squares) adjustment should be applied for all applications related to the coordinates. Many approaches were suggested in order to solve this problem, resulting in equivalent solutions except some restrictions. In this study, we calculated the normal vector of the 3D plane determined by the trace of the VLBI targets based on TLS within GHM (Gauss-Helmert Model). Another numerical test was conducted for the estimation of the Helmert transformation parameters. Since the errors in the horizontal components are very small compared to the radius of the circle, the final estimates are almost identical. However, the estimated variance components are significantly reduced as well as show a different characteristic depending on the target location. The Helmert transformation parameters are estimated more precisely compared to the conventional LESS case. Furthermore, the residuals can be predicted on both reference frames with much smaller magnitude (in absolute sense).

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2935-2940
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• 2023

A polystyrene phantom was developed following the guidance of the International Atomic Energy Association (IAEA) for gamma knife (GK) quality assurance. Its performance was assessed by measuring the absorbed dose rate to water and dose distributions. The phantom was made of polystyrene, which has an electron density (1.0156) similar to that of water. The phantom included one outer phantom and four inner phantoms. Two inner phantoms held PTW T31010 and Exradin A16 ion chambers. One inner phantom held a film in the XY plane of the Leksell coordinate system, and another inner phantom held a film in the YZ or ZX planes. The absorbed dose rate to water and beam profiles of the machine-specific reference (msr) field, namely, the 16 mm collimator field of a GK Perfexion^TM or Icon^TM, were measured at seven GK sites. The measured results were compared to those of an IAEA-recommended solid water (SW) phantom. The radius of the polystyrene phantom was determined to be 7.88 cm by converting the electron density of the plastic, considering a water depth of 8 g/cm². The absorbed dose rates to water measured in both phantoms differed from the treatment planning program by less than 1.1%. Before msr correction, the PTW T31010 dose rates (PTW Freiberg GmbH, New York, NY, USA) in the polystyrene phantom were 0.70 (0.29)% higher on average than those in the SW phantom. The Exradin A16 (Standard Imaging, Middleton, WI, USA) dose rates were 0.76 (0.32)% higher in the polystyrene phantom. After msr correction factors were applied, there were no statistically significant differences in the A16 dose rates measured in the two phantoms; however, the T31010 dose rates were 0.72 (0.29)% higher in the polystyrene phantom. When the full widths at half maximum and penumbras of the msr field were compared, no significant differences between the two phantoms were observed, except for the penumbra in the Y-axis. However, the difference in the penumbra was smaller than variations among different sites. A polystyrene phantom developed for gamma knife dosimetry showed dosimetric performance comparable to that of a commercial SW phantom. In addition to its cost effectiveness, the polystyrene phantom removes air space around the detector. Additional simulations of the msr correction factors of the polystyrene phantom should be performed.

• Archives of Plastic Surgery
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• v.50 no.4
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• pp.370-376
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• 2023

Background The posterior ledge (PL) is a vital structure that supports the implant posteriorly during orbital floor reconstruction. This study describes a technique for mapping the PL in relation to the infraorbital margin (IM) in patients with orbital floor blowout fractures. This study establishes the location of the optic foramen in relation to the PL. Methods Facial computed tomography (FCT) scans of 67 consecutive patients with isolated orbital floor blowout fractures were analyzed using Osirix. Planes of reference for orbital fractures, a standardized technique for performing measurements on FCT, was used. Viewed coronally, the orbit was divided into seven equal sagittal slices (L1 laterally to L7 medially) with reference to the midorbital plane. The distances of PL from IM and location of optic foramen were determined. Results The greatest distance to PL is found at L5 (median: 30.1 mm, range: 13.5-37.1 mm). The median and ranges for each slice are as follows: L1 (median: 0.0 mm, range: 0.0-19.9 mm), L2 (median: 0.0 mm, range: 0.0-21.5 mm), L3 (median: 15.8 mm, range: 0.0-31.7 mm), L4 (median: 26.1 mm, range: 0.0-34.0 mm), L5 (median: 30.1 mm, range: 13.5-37.1 mm), L6 (median: 29.0 mm, range: 0.0-36.3 mm), L7 (median: 20.8 mm, range: 0.0-39.2 mm). The median distance of the optic foramen from IM is 43.7 mm (range: 37.0- 49.1) at L7.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.1
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• pp.55-62
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• 2004

A semi-automatic registration process of determining specified points is presented, which is required to register brain MR images based on Talairach atlas. Generally, ten specified points that define Talairach coordinates are anterior commissure(AC), posterior commissure (PC), anterior feint (AP), posterior point (PP), superior point (SP), inferior point (IP), left point (LP), right point (RP) and two points for the midline of the brain. The suggested method reduces user interaction for S points, and finds the necessary points for registration in a more stable manner by finding AC and PC using two-level shape matching of the corpus callosum (CC) in an edge-enhanced brain M image. Remaining points are found using the intensity information of cutview.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.299-303
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• 2015

Purpose: The objective of this study was to examine the changes in muscle activity on the anterior deltoid muscle depending on the stretch rate of kinesio tape when applying kinesio tape in healthy adult subjects. Methods: This study was a single-blind randomized controlled trial, including 22 healthy participants (male 15, female 7) with no pathology or past history of shoulder who participated voluntarily. Participants applied a different stretch rate of the kinesio tape, and the functional activity was tested. The stretch rate of kinesio tape was 0%, 10%, and 20%. Subjects lifted a weight (5% of their body weight) to their shoulder height. Subjects lifted a weight up to an angle of 90 degrees in the sagittal plane, and muscle activities (biceps brachii, anterior deltoid, middle deltoid, upper trapezius) were assessed using EMG (electromyography). Analysis of muscle activity was divided into two parts (lift weight and keep holding). The EMG activity of each muscle was normalized to the value of reference voluntary contraction (%RVC) and explored using repeated ANOVA. Results: There were no significant differences in muscle activity depending on the ratio of tape stretch when lifting a weight (p>0.05). There were no significant differences in muscle activity depending on the ratio of tape stretch when holding a weight (p>0.05). Conclusion: According to the results of this study, in the case of applying kinesio taping therapy for healthy people, it was found that the stretch rate of the tape does not have an effect on muscle activity.

• Physical Therapy Korea
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• v.27 no.2
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• pp.93-101
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• 2020

Background: For performing various movements well, cooperation between the muscles around the scapula and shoulder has been emphasized. Taping has been widely used clinically as a helpful adjunct to other physiotherapy methods for shoulder pathology and dysfunction treatment. Previous studies have evaluated the effect of taping techniques using dynamic tapes on shoulder function and pain. However, no study investigated the electromyographic (EMG) changes in the shoulder muscles. Objects: This study aimed to investigate the effect of the upper limb offload taping technique using a dynamic tape on EMG activities of the upper trapezius (UT), lower trapezius, serratus anterior (SA), and middle deltoid (MD) muscles during scaption plane elevation. Methods: A total of 26 healthy subjects (19.85 ± 6.40 years, male = 20) volunteered to participate in this study. The subjects were instructed to perform scaption elevation with and without dynamic taping on the shoulder. Shoulder elevation strength tests were performed at 100%, 75%, 50%, and 25%, for the maximal isometric contraction force. Results: There were statistically significant interaction effects between the taping application and shoulder scaption elevation force in EMG activities in the UT (p < 0.05) and MD (p < 0.05). EMG activities in the UT showed significant increases in 50%RVC (reference voluntary contraction, p < 0.05) and 25%RVC (p < 0.01). Furthermore, the EMG activity of the SA significantly increased in 50%RVC (p < 0.01) and 25%RVC (p < 0.01) after dynamic taping. For the MD, the EMG activity level significantly decreased in 100%RVC (p < 0.05). Conclusion: These results indicated that upper limb offload dynamic taping application affects the muscle activities of some shoulder muscles depending on different scaption elevation strength levels. Therefore, we suggest that the upper limb offload dynamic taping can be applied to the shoulders when patients need middle deltoid inhibition or upper trapezius facilitation, such as patients with shoulder impingement syndrome.

• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.392-398
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• 2003

We present a novel concept of a phase-shifting diffraction-grating interferometer, which is intended for the optical testing of concave mirrors with high precision. The interferometer is configured with a single reflective diffraction grating, which performs multiple functions of beam splitting, beam recombination, and phase shifting. The reference and test wave fronts are generated by means of reflective diffraction at the focal plane of a microscope objective with large numerical aperture, which allows testing fast mirrors with low f-numbers. The fiber-optic confocal design is adopted for the microscope objective to focus a converging beam on the diffractive grating, which greatly reduces the alignment error between the focusing optics and the diffraction grating. Translating the grating provides phase shifting, which allows measurement of the figure errors of the test mirror to nanometer accuracy.

• Toxicological Research
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• v.31 no.3
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• pp.227-240
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• 2015

Recent amendment on the Food Sanitation Act in Korea mandated the Minister of Food & Drug Safety to secure the scientific basis for management and reevaluation of standards and specifications of foods. Especially because the current food safety control is limited within the scope of 'Farm to Market' covering from production to retail in Korea, safety control at the plane of true 'Farm to Fork' scope is urgently needed and should include 'total diet' of population instead of individual food items. Therefore, 'Total Diet Study (TDS)' which provides 'closer-to-real' estimates of exposure to hazardous materials through analysis on table-ready (cooked) samples of foods would be the solution to more comprehensive food safety management, as suggested by World Health Organization and Food and Agriculture Organization of the United Nations. Although the protection of diets from hazards must be considered as one of the most essential public health functions of any country, we may need to revisit the value of foods which has been too much underrated by the meaningless amount of some hazardous materials in Korea. Considering the primary value of foods lies on sustaining life, growth, development, and health promotion of human being, food safety control should be handled not only by the presence or absence of hazardous materials but also by maximizing the value of foods via balancing with the preservation of beneficial components in foods embracing total diet. In this regard, this article aims to provide an overview on TDS by describing procedures involved except chemical analysis which is beyond our scope. Also, details on the ongoing TDS in Korea are provided as an example. Although TDS itself might not be of keen interest for most readers, it is the main user of the safety reference values resulted from toxicological research in the public health perspective.

• Journal of Conservation Science
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• v.5 no.2 s.6
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• pp.51-56
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• 1996

This paper deals with the restoration of ancient wooden bridge foundation which excavated in Seta river Shiga Prefecture, Japan. Shiga Archeological Research started a marine archeological investigation of the bridge foundation in 1987. The bridge foundation stricture excavated and have since then recovered about a lots of woods and another materials. The bridge foundation structure constructed log, timbers and stones. The species of those waterlogged wood were identified as two types, hardwood and softwood. Hardwood(log : Cyclobalanopsis) was used for below foundation and softwood (timber' Chamaecyparis obtusa Endl. Cupreessaceae) was used for base structure. One of those timber sample dated by dendrochronology, we asked Dr. Misutani*. The softwood gave a felling date of 567 A.D. In result, the ancient Seta bridge foundation structure had constructed between Asuka and Nara period. We healed the news that ancient bridge foundation excavated at Woljyongyo site in Kyongju, Korea 1987. The bridge foundation Setakarahashi is similar in plane and structure to Woljyongyo structures. The Woljyongyo site report had be of value for reference. We had planning to restore those woods. Hardwood log was got serious damage. The water content varies from 400 to $600\%$. The other timbers water content varies about $200\%$. In the Shiga Center for Archaeological Operations and the Azuchi Castle Archaeological Museum, we set up the PEG impregnation tank. Those wooden objects treated by PEG method. PEG with a molecular weight of 4000. The treatment results may be considered satisfactory. The ancient wooden Seta bridge was reconstructed in Biwako Museum which established in Oct. 1996. We must take care of indoor exhibition environments. (*Nara National Cultual Properties Research Institute).