• Restorative Dentistry and Endodontics
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• v.48 no.1
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• pp.7.1-7.10
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• 2023

Objectives: This study aimed to evaluate the surrounding and underlying shades' effect on the color adjustment potential (CAP) of a single-shade composite used in a thin layer. Materials and Methods: Cylinder specimens (1.0 mm thick) were built with the Vittra APS Unique composite, surrounded (dual specimens) or not (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens were also built only with the control composites. Each specimen's color was measured against white and black backgrounds or the simple control specimens with a spectrophotometer (CIELAB system). The whiteness index for dentistry (WI_D) and translucency parameters (TP₀₀) were calculated for simple specimens. Differences (ΔE₀₀) in color between the simple/dual specimens and the controls were calculated. The CAP was calculated based on the ratios between data from simple and dual specimens. Results: The Vittra APS Unique composite showed higher WID and TP₀₀ values than the controls. The highest values of ΔE₀₀ were observed among simple specimens. The color measurements of Vittra APS Unique (simple or dual) against the control specimens presented the lowest color differences. Only surrounding the single-shade composite with a shaded composite barely impacted the ΔE₀₀. The highest CAP values were obtained using a shaded composite under simple or dual specimens. Conclusions: The CAP of Vittra APS Unique was strongly affected by the underlying shade, while surrounding this composite with a shaded one barely affected its color adjustment.

• Anatomy and Cell Biology
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• v.56 no.3
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• pp.374-381
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• 2023

Although the epiglottis plays a vital role in deglutition, histological studies of the epiglottis and surrounding ligaments associated with swallowing dysfunction are limited. Therefore, we performed histological observations to clarify age-related changes in the morphological characteristics of the epiglottis and surrounding structures. Tissue samples comprising the epiglottis and surrounding structures were collected from corpses that were both orally fed and tubefed during their lifetimes. Following hematoxylin and eosin, Elastica Van Gieson, and immunohistochemical staining procedures, the chondrocytes, connective tissue, and glandular tissue were observed under the epiglottis epithelium, and intervening adipose tissue was observed in the surrounding area. Fatty degeneration of acinar cells was also observed in the glandular tissue, possibly because of aging. Bundles of elastic fibers were present around the vascular wall in the peri-epiglottic ligament, but some were reduced. Furthermore, large amounts of collagen fibers ran toward and through the cartilage, whereas the mesh-like elastic fibers stopped in front of the cartilage. Microfibrils considered to be oxytalan fibers, which are thinner and shorter than elastic fibers, were observed around the vascular wall and in the fiber bundles. Age-related changes included connective tissue fibrosis shown by the large amount of collagen fibers, atrophy of salivary glands, and an accompanying increase in adipose tissue. Regarding stretchability and elasticity, the elastic fibers may have an auxiliary function for laryngeal elevation during deglutition. This suggests that disuse atrophy of the laryngeal organs with or without oral intake might reduce the amount of elastic fiber in older adults.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.19-26
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• 2017

Purpose: The application of density override is very important to minimize dose calculation errors by fiducial markers of metal material in proton treatment plan. However, density override with actual material of the fiducial marker could make problem such as inaccurate target contouring and compensator fabrication. Therefore, we perform density override with surrounding material instead of actual material and we intend to evaluate the usefulness of density override with surrounding material of the fiducial marker by analyzing the dose distribution according to the position, material of the fiducial marker and number of beams. Materials and Method: We supposed that the fiducial marker of gold, steel, titanium is located in 1.5, 2.5, 4.0, 6.0 cm from the proton beam's end of range using water phantom. Treatment plans were created by applying density override with the surrounding material and actual material of the fiducial marker. Also, a liver cancer patient who received proton therapy was selected. We located the fiducial marker of gold, steel, titanium in 0, 1.5, 3.5 cm from the proton beam's end of range and the treatment plans were created by same method with water phantom. Homogeneity Index(HI), Conformity Index(CI) and maximum dose of Organ At Risk(OAR) in Planning Target Volume(PTV) as the evaluation index were compared according to the material, position of the fiducial marker and number of beam. Results: The HI value was more decreased when density override with surrounding material of the fiducial marker was performed comparing with density override with actual material. Especially the HI value was increased when the fiducial marker was located farther from the proton beam's end of the range for a single beam and the fiducial marker's position was closer to isocenter for two or more beams. The CI value was close to 1 and OAR maximum dose was greatly reduced when density override with surrounding material of the fiducial marker was performed comparing with density override with actual material. Conclusion: Density override with surrounding material can be expected to achieve more precise proton therapy than density override with actual material of the fiducial marker and could increase the dose uniformity and target coverage and reduce the dose to surrounding normal tissues for the small fiducial markers used in clinical practice. Most of all, it is desirable to plan the treatment by avoiding the fiducial marker of metal material as much as possible. However, if the fiducial marker have on the beam path, density override of the surrounding material can be expected to achieve more precise proton therapy.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.17-24
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• 2006

Purpose : The objective of this study was to investigate the effect of TMJ disc displacement on the TMJ disc configuration and surrounding osseous structure. Materials and Methods : The proton density and 72-weighted MR images of 57 TMJs were retrospectively studied. These TMJs were divided into three groups according to the anterior disc displacement status on MR sagittal images, those were the normal, anterior disc displacement with reduction (ADWR), anterior disc displacement without reduction (ADWOR). The frequency of disc configuration and surrounding bony change, the border status between articular disc and retrodiscal tissue were investigated according to the positional change of articular disc. Results : There were significant statistical differences of chi-square statistics of TMJ disc configurational type between normal and ADWR/ADWOR group, respectively. Surrounding bony change frequently appeared in ADWOR and a statistically significant difference of chi-square statistics of bony change frequency between normal and ADWOR group was observed. Conclusion : These results suggested that the disc configuration and bony change of TMJ are strongly related to TMJ disc displacement.

• Journal of architectural history
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• v.24 no.4
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• pp.7-18
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• 2015

Gwanghwamun was dismantled and displaced to the east side of the palace, at that time, the Chosun Government General Building was constructed in the Gyeongbokgung palace. After the Korea war, it remained as a stonework as a result of the fire. In 1968, The Gwanghwamun came back in front of the palace. Then, why it was rebuilt in the 3rd Republic period? What was the reason for selecting concrete? Since the May 16 coup, the military regime had been utilized palace and surrounding urban space to show a visible practice of modernization. Attempting the combination of modern technology in the 1960s and traditional cultural property and reconstructing a city as a pretext called Cultural Heritage conservation was a typical mechanism of the 1960s. In this study, I start by assume that reconstructing Gwanghwamun(1968) was a part of project to change the surrounding urban space of Gwanghwamun than to preserve cultural assets. Two main contributions of the study are following. First, I collect availabe data on the reconstructing surrounding urban space of the Gwanghwamun and re-organize them in chronological order to make them as fragments of a map. Second, I analysis and identify the nature and phase of the Gwanghwamun reconstruction.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.1-9
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• 2014

The purpose of this study was to investigate the muscle mechanical properties of the pelvic axial pre-rotational movement for the Jireugi in the Taekwondo Juchumseogi stance. Eleven elite Taekwondo Poomsae athletes participated. Each participant performed 5 right hand Jireugi in Juchumseogi stance as fast and strong as possible while their motion was recorded by a 3D motion analysis system and the ground reaction forces by two force plates. The power and work of the muscular group surrounding the waist were analyzed to verify the effect of the stretch-shortening cycle (SSC) theory. The cause of the greater power seems to be the application of the SSC by the muscles surrounding the waist during the preparation phase of the pre-rotation group. For the none pre-rotation group, they only used the concentric contraction of the muscles surrounding the waist. Because the pre-rotation group used the SSC theory, they had the effect of shortening of the range of movement, creating a fast and more powerful rotation, thus anticipating the increase the magnitude of impact.

• Journal of IKEEE
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• v.22 no.1
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• pp.74-79
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• 2018

We analyzed the relationship between center potential and subthreshold swing (SS) of Junctionless Cylindrical Surrounding Gate (JLCSG) and Junctionless Double Gate (JLDG) MOSFET. The SS was obtained using the analytical potential distribution and the center potential, and SSs were compared and investigated according to the change of channel dimension. As a result, we observed that the change in central potential distribution directly affects the SS. As the channel thickness and oxide thickness increased, the SS increased more sensitively in JLDG. Therefore, it was found that JLCSG structure is more effective to reduce the short channel effect of the nano MOSFET.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.278-282
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• 2018

We propose a SPICE model of drain-induced barrier lowering (DIBL) for a junctionless cylindrical surrounding gate (JLCSG) MOSFETs. To this end, the potential distribution in the channel is obtained via the Poisson equation, and the threshold voltage model is presented for the JLCSG MOSFET. In a JLCSG nano-structured MOSFET, a channel radius affects the carrier transfer as well as the channel length and oxide thickness; therefore, DIBL should be expressed as a function of channel length, channel radius, and oxide thickness. Consequently, it can be seen that DIBLs are proportional to the power of -3 for the channel length, 2 for the channel radius, 1 for the thickness of the oxide film, and the constant of proportionality is 18.5 when the SPICE parameter, the static feedback coefficient ${\eta}$, is between 0.2 and 1.0. In particular, as the channel radius and the oxide film thickness increase, the value of ${\eta}$ remains nearly constant.

• Structural Engineering and Mechanics
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• v.62 no.1
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• pp.113-123
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• 2017

The bi-material elastic system consisting of the circular hollow cylinder and the infinite elastic medium surrounding this cylinder is considered and it is assumed that on the inner free face of the cylinder a point-located axisymmetric time harmonic force, with respect to the cylinder's axis and which is uniformly distributed in the circumferential direction, acts. The shear-spring type imperfect contact conditions on the interface between the constituents are satisfied. The mathematical formulation of the problem is made within the scope of the exact equations of linear elastodynamics. The focus is on the frequency-response of the interface normal and shear stresses and the influence of the problem parameters, such as the ratio of modulus of elasticity, the ratio of the cylinder thickness to the cylinder radius, and the shear-spring type parameter which characterizes the degree of the contact imperfectness, on these responses. Corresponding numerical results are presented and discussed. In particular, it is established that the character of the influence of the contact imperfection on the frequency response of the interface stresses depends on the values of the vibration frequency of the external forces.

• Journal of Korea Multimedia Society
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• v.18 no.9
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• pp.1008-1018
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• 2015

In this paper, we propose a method that constructs a saliency map in which important regions are accurately specified and the colors of the regions are less influenced by the similar surrounding colors. Our method utilizes LBP(Local Binary Pattern) histogram information to compare and analyze texture information of surrounding regions in order to reduce the effect of color information. We extract the saliency of stereoscopic images by integrating a 2D saliency map with depth information of stereoscopic images. We then measure the distance between two different sizes of the LBP histograms that are generated from pixels. The distance we measure is texture difference between the surrounding regions. We then assign a saliency value according to the distance in LBP histogram. To evaluate our experimental results, we measure the F-measure compared to ground-truth by thresholding a saliency map at 0.8. The average F-Measure is 0.65 and our experimental results show improved performance in comparison with existing other saliency map extraction methods.