• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.9-15
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• 1997

The study area is located in the Central Bransfield Basin, Antarctica. To analyze the morphology of seafloor, structure of basement, and seismic stratigraphy of the sedimentary layers, we have acquired, processed, and interpreted the multi-channel seismic data. The northwest-southeastern back-arc extension dramatically changes seafloor morphology, volcanic and fault distribution, and basin structure along the spreading ridges. The northern continental shelf shows a narrow, steep topography. In contrast, the continental shelf or slope in the south, which is connected to the Antarctic Peninsula, has a gentle gradient. Volcanic activities resulted in the formation of large volcanos and basement highs near the spreading center, and small-scale volcanic diapirs on the shelf. A very long, continuous normal fault characterizes the northern shelf, whereas several basinward synthetic faults probably detach into the master fault in the south. Four transfer faults, the northwest-southeastern deep-parallel structures, controlled the complex distributions of the volcanos, normal faults, depocenters, and possibly hydrocarbon provinces in the study area. They have also deformed the basement structure and depositional pattern. Even though the Bransfield Basin was believed to be formed in the Late Cenozoic (about 4 Ma), the hydrocarbon potential may be very high due to thick sediment accumulation, high organic contents, high heat flow resulted from the active tectonics, and adequate traps.

• The korean journal of orthodontics
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• v.29 no.5 s.76
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• pp.535-549
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• 1999

The Purposes of this study were to investigate the initial tissue changes on the teeth and surrounding tissues under contraction and intrusive force by contraction UTA. A control and experimental dogs, 10-months in age, were studied. Contraction and intrusive force(60gm) were applied at upper four incisors by contraction UTA. Experimental dogs were sacrificed at 2 weeks and 4 weeks after force application, respectively. In this study, 2 experimental groups were designed by the duration of force applied(E1, E2). The specimens were taken around the upper first and second incisor in each groups and were prepared for the H-E and MT stain for light microscopic observation. From the results of the study, the following conclusions may be drown. : 1. In control group, the periodontal ligament width was constant from apical third to cervical third of the root and periodontal fiber arrangement was horizontal or oblique in cervical third, oblique in middle third and apical third. In alveolar bond, smooth appearance was shown with osteoblast. 2. In experimental group 1, in proportion to force was concentrated at labial middle third and apical third of root of the upper first and second incisors, root of these tooth tipped labially and intruded at a time. 3. In experimental group 2, periodontal ligament width and arrangement was similar to control and observed strong calcified response at the labial middle third of root. But, alveolar bond resorption and cementum resorption were as before seen at labial middle third and apical third of root that force was concentrated.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.27-35
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• 1991

An interstitial radiofrequency needle electrode system was constructed for interstitial heating of brain tissue. Radiofrequency electrodes with Thermotron RF 8 were tested in an agar phantom and in a normal canine brain to determine how variations in physical factors affected temperature distributions. Temperature distributions were checked after heating with 1 mm diameter needle electrode implants on the corners of 1 and 2 cm squares in a phantom and plot isotherms for various electrodes arrangement. We observed that the 1 cm square array would heat a volume with a 1.25 cm radius circular field cross section to therapeutic temperatures ($90\%$ relative SAR using Tm) and the 2 cm square array with a 1.75 cm radius rectangular field with central inhomogeneity. With 2 cm long electrode implants, we observed that the 1 cm square array would heat a 3 cm long sagittal section to therapeutic temperature ($90\%$ relative SAR using Tm). We found that radiofrequency electrodes could be selected to match the length of the heating area without affecting its performance. The histopathological changes associated with RF heating of normal canine brains have been correlated with thermal distributions. RF needle electrode heating was applied for 50min to generate tissue temperatures of $43^{\circ}C$. We obtained a quarter of the heated tissue material immediately after heating and sacrificed at intervals from $7\sim30$days. The acute stage (immediately after heating) was demonstrated by liquefactive necrosis, pyknosis of neuronal element in the gray matter and by some polymer-phonuclear leukocytes infiltration. The appearance of lipid-laden macrophages surrounding the area of liquefaction necrosis was demonstrated in all three sacrificed dogs. Mild gliosis occurring around the necrosis was demonstrated in the last sacrificed (Days 30) canine brain.

• Radiation Oncology Journal
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• v.28 no.1
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• pp.32-38
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• 2010

Purpose: Although radiation-induced fibrosis is one of the common sequelae occurring after irradiation of skin and soft tissues, the treatment methods are not well standardized. This study aimed to establish the skin fibrosis mouse model by fractionated radiation for the further mechanism studies or testing the efficacy of therapeutic candidates. Materials and Methods: The right hind limbs of BALB/c mice received two fractions of 20 Gy using a therapeutic linear accelerator. Early skin damages were scored and tissue fibrosis was assessed by the measurement of a leg extension. Morphological changes were assessed by H&E staining and by Masson's Trichrome staining. TGF-${\beta}1$ expression from soft tissues was also detected by immunohistochemistry and PCR. Results: Two fractions of 20 Gy irradiation were demonstrated as being enough to induce early skin damage effects such as erythema, mild skin dryness, dry and wet desquamation within several weeks of radiation. After 13 weeks of irradiation, the average radiation-induced leg contraction was $11.1{\pm}6.2mm$. Morphologic changes in irradiated skin biopsies exhibited disorganized collagen and extracellular matrix fibers, as well as the accumulation of myofibroblasts compared to the non-irradiated skin. Moreover, TGF-${\beta}1$ expression in tissue was increased by radiation. Conclusion: These results show that two fractions of 20 Gy irradiation can induce skin fibrosis in BALB/c mice accompanied by other common characteristics of skin damages. This animal model can be a useful tool for studying skin fibrosis induced by radiation.

• Archives of design research
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• v.19 no.5 s.67
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• pp.129-138
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• 2006

It is expected that the typical lifestyle of the future will be transformed into an opulent and comfortable existence as the quality of life improves due to the increase in household income and reduction in working hours. In the meantime, as the standard of living becomes increasingly more comfortable and plentiful, the toll on physical health becomes magnified as a result of obesity and insufficient exercise caused by super nutrition and change in labor conditions (from physical labor to mental labor). This has instigated a deep awareness in fitness on the part of many people, forcing them to recognize the significance of daily exercise and physical activity. The high annual growth rate in the fitness and athletic apparatus market, which is more than 20%, is attributed to this phenomenon. The Elliptical Cross Trainer(ECT), which has drawn wide attention recently, is a non-impact athletic apparatus that not only promotes exercise of the upper body parts in such sports as skiing but also the exercise of lower parts of the body on a treadmill. It is a type of cross training athletic gear that has been developed for aerobic exercise throughout the entire body. It has already formed a market as big as that of the treadmill in Europe, America, etc. Recently, its demand is growing sharply in the Korean markets as well as those in Northeast Asian countries, Despite such demand increase and expansion, since most of the expensive ECTs are exclusively supplied by suppliers in only a few advanced countries, localization of the ECT is urgently required in order to enhance competitiveness of Korean manufacturers and to expand the market. This paper introduces the process and results of a design-engineering cooperative study that was peformed for the development of the ECT.

• Archives of design research
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• v.19 no.5 s.67
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• pp.85-94
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• 2006

In the 2000s, character animation technique is used at domestic TV character animation ads of diverse items displaying new character patterns and expression techniques of a high level. This study intends to identify the characteristics of TV character animation ads based ell character aesthetic theory and advertising rhetoric theory, and based on these findings, analyze trend and stream of expression in TV character animation ads by examining and classifying advertisements released in the past four years by items, character patterns and expression techniques. The results showed that TV character animation ads have been concentrated on confectionery, beverages and foods in the past, but the items have been diversified through the years. With reference to character patterns, personal and animal characters had made the main pattern, but recently product, virtual and composite characters are on the increase. In expression techniques, cell animation technique was found to be the most frequently used technique, which was followed by full-3D, cell and live action, cell and 3D and the clay animation technique. A trend like this suggests that TV character animation advertising items will continue to increase in line with the participation level of targets. In the meantime, personal and animal characters will continue to make the leading character pattern, while virtual and composite character patterns emerge in new forms. In expression techniques, live action combined with 30 technique and techniques using new expression materials will appear with cell animation technique as a central figure. As a whole, Korean character animation advertisement is expected to keep on growing to a new dimension in the aspect of items, character patterns and expression technique.

• Archives of design research
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• v.19 no.5 s.67
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• pp.203-212
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• 2006

With interests and participation in the costumeplay that mimics characters appeared on carton or animation in recent days, the costumeplay becomes one of cultural phenomena. Using a qualitative research method, this study identified costumeplayers' costume consumption pattern and explored its meanings from the perspective of consumption culture. Indeed, this study intended to help for understanding costumeplayer group as a consumer, and to provide basic knowledge about new market analysis related to fashion design and marketing. The results from the analyzing participant observation and in-depth interviews data are as follows: first, costumeplayers usually begin costumeplay by friends' invitations or by themselves and then continue on participating. Through the costumeplay, participants have benefits such as fun, departure from the daily life, and social interaction. Second, participants acquire costumes through purchase, rent, producing or combination of daily wear, but both purchase and rent account high. Third, the meanings of consumption culture in costumeplay include consumption behavior repeating possession and disposal. Also, costumeplayers concerns efficiency when purchasing or renting the costumes, and internet is a place where information search, comparison, and actual purchasing are occurred. Based on the results, fashion design and marketing implication, limitation of this study and further research ideas were suggested.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.45-52
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• 1995

This study is to compare A point doses in human pelvic phantom by film dosimetry, computer planning and manual calculation by using of along-away table. We developed tissue equivalent human pelvic phantom composed of four pieces of cylindrical acryl tubes with water, to simulate intracavitary radiation (ICR) in patients with cervix cancer. When the phantom assembled from 4 pieces, it has a small space for inserting Fletcher-Suit-Delclos applicator like a human vagina. Fletcher-Suit-Delclos applicator inserted into the space was packed tightly with furacin gauzes, and three $^{137}Cs$ sources with radioactivity of $15.7mg\;Ra-eq$ were inserted into the tandem. For the film dosimetry, two pieces of X-OMAT V film (Kodak Co.) of which planes include point A, were arranged orthogonally in the slits between phantoms. A point dose and iso-dose curves were measured by means of optical densitometer. A point doses by film dosimetry, RTP system and manual calculation by using of along-away table were compared, and iso-dose curves by film dosimetry and computer planning were also compared. The dose of A point was 51.2cGy/hr by film dosimetry, 46.7cGy/hr by RTP system and 47.9 cGy/hr by along-away table. A point dose by computer planning was similar to the dose by calculation using of along-away table with acceptable accuracy $({\pm}3%)$, however, the dose by film dosimetry was different from two others with about 10% error. Since most clinical beams contains a scatter component of low energy photons, the correlation between optical density and dose becomes tenuous. In addition, film suffers from several potential errors such as changes in processing conditions, interfilm emulsion differences, and artifacts caused by air pockets adjacent to the film. For these reasons, absolute dosimetry with film is impractical, however, it is very useful for checking qualitative patterns of a radiation distribution. In future, solid state dosimeter such as TLD must be used for the dosimetry of ionizing radiation. When considerable care is used, precision of approximately 3% may be obtained using TLD.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.453-460
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• 2009

The purpose of this study was to determine the dose distribution and image quality according to slice thickness and BC(beam collimation) in the gantry aperture. CT scans were performed with a 64-slice MDCT(Brilliance 64, Philips, Cleveland, USA) scanner. To determine the dose distribution according to BC, a ionization chamber was placed at isocenter and 5, 10, 15, 20, 25 and 30 cm positions from the isocenter in the 12, 3, 6 and 9 o'clock directions. The dose distribution for phantom scan was also measured using CT head and body dose phantom with five holes at the center of the phantom and the positions of the 12, 3, 6 and 9 o'clock directions. The image noise measurement for different BCs was performed using an AAPM CT phantom. Water-filled block of the phantom was moved by 5 cm or 10 cm to the 12 o'clock direction, and the image noise was measured at the center of the phantom, and the points of 12, 3, 6 and 9 o'clock direction respectively. Some points were placed beyond the scan field of view (SFOV), so that measurement was not possible at that points. The results are as follows: The CTDIw showed a larger decrease as the source goes farther from the iso-center or the BC became wider. The CTDIw depends on the BC width more than the number of the channel of a detector array. The value of CTDIW decreased with increasing BC, but the value decreased 16.6~31.9% in the head phantom scan in air scan and 51.0~64.5% in the body phantom scan. The value of the noise was 3.9~5.9 in the head and 5.3~7.4 in the body except for BC of $2{\times}0.5\;mm$, regardless of the degree of deviation from the iso-center. When a subject was located within the SFOV, the position did not significantly affect image quality even if the subject was out of the center.

• Progress in Medical Physics
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• v.9 no.2
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• pp.77-88
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• 1998

Wedge shaped isodoses are desired in a number of clinical situations. Hard wedge filters have provided nominal angled isodoses with dosimetric consequences of beam hardening, increased peripheral dosing, nonidealized gradients at deep depths along with the practical consequendes of filter handling and placement problems. Dynamic wedging uses a combination of a moving collimator and changing monitor dose to achieve angled isodoses. The segmented treatment tables(STT) that monitor unit setting by every distance of moving collimator, was induced by numerical formular. The characteristics of dynamic wedge by STT compared with real dosimetry. Methods and Materials : The accelerator CLINAC 2100C/D at Yonsei Cancer Center has two photon energies (6MV and 10MV), currently with dynamic wedge angles of 15$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$ and 60$^{\circ}$. The segmented treatment tables(STT) that drive the collimator in concert with a changing monitor unit are unique for field sizes ranging from 4.0cm to 20.0cm in 0.5cm steps. Transmission wedge factors were measured for each STT with an standard ion chamber. Isodose profiles, isodose curves, percentage depth dose for dynamic wedge filters were measured with film dosimetry. Dynamic wedge angle by STT was well coincident with film dosimetry. Percent depth doses were found to be closer to open field but more shallow than hard wedge filter. The wedge transmission factor were decreased by increased the wedge angle and more higher than hard wedge filters. Dynamic wedging probided more consistent gradients across the field compared with hard wedge filters. Dynamic wedging has practical and dosimetric advantages over hard filters for rapid setup and keeping from table collisions. Dynamic wedge filters are positive replacement for hard filters and introduction of dynamic conformal radiotherapy and intensity modulation radiotherapy in a future.