• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.1
• /
• pp.39.4-40
• /
• 2017

According to the Korean government's Long-term Space Development Plan 2040, "Creative space science research" is included in a statement to investigate the origin and evolution of the universe by conducting a series of Korean space telescope missions: launch of space telescopes on a small satellite and an international collaboration explorer by 2020, a mid-size domestic space telescope by 2030, and a large size Korea leading international space telescope by 2040. We studied the feasibility of the future Korean Space Telescope (KST) for a mid-size domestic satellite platform. In order to pursue the uniqueness of the science program, we consider a wide range of observing wavelength (0.2um ~ 2.0um) with a spectral resolution of R~6 in the NUV and optical bands, and R~30 for NIR, utilizing an off-axis TMS(Three Mirror System) optics with a wide field of view ($2{\times}4$ degrees) which is optimized for ultra-low surface brightness sources. The main science goals of the mission include investigations of the galaxy formation, cosmic web, and the cosmic background radiation in the NUV-NIR regions. In this paper, we present the science cases and several technical challenges to be resolved along with the future milestones for the success of the KST mission.

• Journal of architectural history
• /
• v.21 no.1
• /
• pp.83-98
• /
• 2012

The starting point of this study is the concerning of simple behavioral pattern that whoever enters the inner space with taking off his shoes should go out from the position where he laid his shoes. The using of Ondol (floor heating room) and Maru (lifted wood floor) had changed the architectural space from chair-sitting to floor-sitting space, and it also made the behavior of taking off the shoes at the entrance of building and stepping on the lifted floor. This simple behavior has possibility to make lots of changes to the culture of architectural design. With this noticeable point, this paper is talking about the cultural feature of Korean traditional architecture, especially about the influence of tanking off and putting on shoes. The matter of shoes has changed diverse aspects of building and layout planning. It maximized the difference between front and rear part of building and characterized the lateral extension of Korean traditional house. The ritual space also had evolved from chair-sitting to floor-sitting space according to the type of ritual behavioral pattern. The change on the single building level had influenced on the layout planning of architectural complex. For examples, the parallel layout of ChangDeok-gung palace and the long sequential process to the main pavilion of Buddhist temple are the result of the matter of shoes. And NuGak(樓閣), the double-storied pavilion, on the axis of entering sequence's node is one of the unique planning elements that makes possible to go through the building without taking off the shoes and also makes upper level space for staying. In short, Korean traditional architecture that has the chair-sitting spatial origin of the East Asian cultural sphere has pursued new architectural issues and planning methods according to evolution to the floor-sitting culture.

• Journal of architectural history
• /
• v.23 no.6
• /
• pp.7-20
• /
• 2014

The purpose of this paper is to study on the architecture and extension project for the Church of St. Lorenzo. This study is composed of a through analysis of the extension elements on the church building and extension type for extension project of the Church of St. Lorenzo. The results of study are as follows: 1. The extension project for the Church of St. Lorenzo was basically consisted of the concept of a horizontal extension plan through both the interior and exterior space of the church building. This project was the plan of concept of additional or affixing extension through existing spaces with necessary spaces to make up for the previous simple space and form as well as functional aspect. 2. The unit spaces of the nave, the aisle, the small chapels bilaterally adorning the aisles, the transept and the chapels around transepts, and the sacristies by the extension project for the Church of St. Lorenzo is composed of regulation, balance and harmony as geometric space composition according to simple proportion system on whole and parts as well as parts and parts, through the definite articulation by each space zoning. 3. The most important innovative aspect different to previous churches in the extension project for the Church of St. Lorenzo is the compositive system of each other symmetrical spaces through long centrical axis of central part, applying the module system for horizontal arrangement. In particular, the use of regular module on repetition and proportion of rhythm from architectural composition system was precisely composed with the alter that consists of visual focus to express more accurate perspective.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.1 no.2
• /
• pp.23-33
• /
• 1991

Mn - Zn Ferrite has the natural characteristics of incongruent melting and the zinc oxide evaporation while the crystal is being grown. As a result of these, it comes into existence to be a non-uniform distribution of cations along the crystal growth axis and also Pt particles are usually precipitated into the crystals in Bridgman method since the melt zone is maintained for a long time in the crucible. These have bad effects on the magnetic properties of ferrites. But, to overcome these faults and then acquire the better single crystals. new modified growth method was developed and the growth factors were investigated as following: melt height in the crucible, surface tension and density of melt, the behavior of melt at interface, the shapes of crucible and solid -liquid interface, powder feeding rate, and the crystal growing speed. In additon, when we analyzed the compositional fluctuations of grown crystals, they were supressed within 1.5 mol% $Fe_20_3$, 2 mol% MnO, ZnO respectively with comparing to initial composition of crystal and the microstructures of crystals on the(110) plane were observed by optical microscope through the chemical etching technique and the magnetic properties were determined.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.1
• /
• pp.12-20
• /
• 2007

Purpose: The purpose of this study was to compare the fracture strength of the zirconia monolithic all-ceramic crowns according to the thickness (0.5mm, 0.8mm, 1.1mm) and metal-ceramic crowns (1.0mm, 1.5mm) Material and method: Twelve crowns for each of 3 zirconia crown groups were fabricated using CAD/CAM system (Kavo, Germany) and twelve crowns for each of 2 metal-ceramic crown groups were made by the conventional method. All crowns were luted to the metal dies using resin cement. Half of the specimens were exposed to thermocycling ($5-55^{\circ}C$, 1 Hz) and cyclic loading (300,000 cycles, 50N). Subsequently, all crowns were mounted on the testing jig in a universal testing machine. The load was directed at the center of crown with perpendicular to the long axis of each specimen until catastrophic failure occurred. Analysis of variance and Tukey multiple comparison test (P<.05) were used for statistical analysis of all groups, and paired t-test (P<.05) was followed for statistical comparison between each groups' fracture load before and after cyclic loading. Results: 1. The fracture strength of the zirconia monolithic crowns and the metal-ceramic crown increased as thickness increased (P<.05). 2. The cyclic loading and thermocycling significantly decreased the fracture strength of the zirconia monolithic crowns (P<.05). 3. The standard deviation of fracture strength of the zirconia monolithic crowns was very low. Conclusion: The fracture strength of the zirconia monolithic crowns for the posterior area tends to be higher with thickness increased and 0.8mm or over in thickness is recommended to have similar or over the fracture strength of metal-ceramic crowns.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.2
• /
• pp.256-261
• /
• 2000

Trauma to the tooth is the most common accidents in pediatric dentistry and tooth fracture occurs frequently. Fracture is classified into crown fracture, root fracture, and crown-root fracture which involves both. Also, it is classified into simple or complicated fracture depending on whether the pulp is exposed or not. When the fracture is extended down to the subgingival level following the long axis of the root, or when more than 1/3 of the root is involved, extraction is the primary treatment. But alternative treatment such as extruding the root fragment with orthodontic force and restoring it, or intentionally extracting the tooth and replanting it to a position which it can be restored. This is a case report on intentional replantation of a traumatized maxillary central incisor with crown-root fracture of a patient with mixed dentition. The teeth was extracted and immediate endodontic treatment, retrograde filling and resin restoration were carried out.

• Journal of Yeungnam Medical Science
• /
• v.28 no.1
• /
• pp.77-83
• /
• 2011

Non-islet cell tumor-induced hypoglycemia (NICTH) is associated with mesenchymal tumor types, including hemangiopericytoma, fibrosarcoma, mesothelioma, and neurofibroma, as well as carcinoma of the liver, adrenal glands, and kidneys. Non- islet cell tumors induce hypoglycemia by overproducing an abnormal form of insulin-like growth factor II (IGF m. Complete removal of the tumor or reduction of the tumor mass is a successful therapeutic strategy in cases of NICTH. However, if the tumor re-grows, curative resection is nearly impossible, and hypoglycemia occurs repeatedly. Glucocorticoids are effective in terms of long-term relief from hypoglycemia through promotion of gluconeogenesis in the liver, tumor suppression, production of 'big'-IGF-II, and correction of the attendant biochemical abnormalities involving the growth hormone (GH)-IGF axis. We found that administration of corticosteroid therapy to a patient suffering from NICTH resulted in improvement of hypoglycemia associated symptoms.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.10
• /
• pp.1367-1373
• /
• 2001

This study used fowl sperm from three White Leghom rooster reared at our laboratory. Semen samples were exposed to the magnetic field strengths of from 650 to 5700 Gauss for one. two, or three days to investigate the influence of magnetic field on the orientation of fowl spermatozoa. Fowl spermatozoa were found to orient with their long axis of heads perpendicular to the magnetic field direction. The fowl spermatozoa were initially influenced when magnetic field intensities were from 650 to 5700 Gauss and the highest values (70.67, 72.49 and 71.79%) were found in the 5700 Gauss treatment at one, two, and three days exposure, respectively. Although percentages of the perpendicular oriented fowl spermatozoa increased along with the enhancement of the magnetic field intensity, the degree of orientation was only significantly higher in the treatments having the magnetic field strength from 1500 to 5700 Gauss than that in the control treatment at all exposure time. In addition, the experimental results also showed that the percentages of all orientational types of fowl spermatozoa (perpendicular category including upward perpendicular and downward perpendicular and parallel type consisting of leftward parallel and rightward parallel) in all treatments tended to be stable during exposure time. From the results of this study. it is suggested that (1) the diamagnetic anisotropy of the inside structural components of fowl spermatozoa induce them to orient perpendicular to the magnetic field direction, (2) the degree of orientation increased according to the enhancement of magnetic field strengths, (3) fowl spermatozoa had not an high sensitivity to the magnetic field, and the level of perpendicular orientation of fowl spermatozoa in this study is nearly similar to that of cattle sperm in the study of Suga et al. (2000).

• Imaging Science in Dentistry
• /
• v.37 no.3
• /
• pp.133-138
• /
• 2007

Purpose: The purpose of this study was to evaluate the morphologic features of posterior edentulous mandible for Korean patients using cross-sectional CT images. Materials and Methods: Computed tomographic cross-sectional views taken in 2004 and 2005 at Seoul National University Dental Hospital were analyzed by an oral and maxillofacial radiologist. Four indices were measured to meet the purpose of this study: 1) the horizontal distance between the alveolar crest and mandibular canal (Type), 2) the angle of the mandibular long axis (Angle), 3) the bucco-lingual location of mandibular canal, and 4) the depth of the submandibular fossa. The averages and standard deviations of the measurements were compared according to the location (the first and second molar area) and sex of the patients. Results: Statistically significant difference was found in Type, Angle, and submandibular fossa depth between the first and second molar area (p<0.05). However, there was no significant difference between men and women in any of the measured indices. Most of the mandibular canals were located in lingual side of posterior mandible. Conclusion: More care should be taken when an implant is installed on the mandibular second molar area.

• Korean Journal of Human Ecology
• /
• v.17 no.6
• /
• pp.1205-1213
• /
• 2008

Material is a factor for maximizing formative aspect among fashion design factors. Therefore, central axis of modern fashion is performing various trials for escaping from existing cloth and searching for artistic value. Especially, Korean paper is a formative material, which is manufactured through traditional manual work in Korea. The material is used in various fields on the basis of its aesthetic feature. Especially, fashion field performs handcraft activity on the basis of mulberry pulp, which is a prime material of Korean paper. Because the activity can be reinterpreted by world designers, who want to find motive of fashion material in the third world, it is necessary to perform experimental study for developing expressive form on the basis of diversity of Korean paper material. Therefore, the purpose of this study is to perform experimental study by focusing on the development of Korean paper material in order to express formative feature. The study purposes are as follows. The first purpose is to reinterprete the theory through actual work of fiber formation using Korean paper in the current flow where art and design field are fused and compromised. The second purpose is to suggest vision of material development on the basis of formative feature to fashion world focusing its eyesight to Asia and the third countries. The study results are as follows. First, Korean paper has been evaluated as proper material for the fusion of design and art because of its handicraft feature, long-term preservation, heat insulation, absorption, diversity and eastern feature. Second, the study performed various trials for artistic dress material by developing 12 Korean paper works and suggested the development of new material on the basis of formative feature of modem fashion industry.