• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.5
• /
• pp.87-103
• /
• 2008

In recent years, the field of THz photonics based on THz pulse technology has gained tremendous, world-wide interest as a new exciting research subject. With a possibility of many commercial applications as well as fundamental scientific achievements in the field, many advanced nations are stepping up their effort in advancing the field of THz photonics. This fact is supported by the observation of the significant increase in the number of papers on THz pulse technology presented in renowned international journals and conferences. The subject that is interesting for the THz application is the development of THz pulse sources and detectors, and other passive devices. In this paper, we present a brief review on some of the key devices and their relavant measurement techniques such as THz photoconductive antennas, optical rectification, difference frequency geneneration with quasi-phase matching structures, electro-optic sampling, high speed real time measurements, THz transmission lines, and other various waveguide structures.

• Journal of Broadcast Engineering
• /
• v.14 no.6
• /
• pp.661-675
• /
• 2009

The carelessly and illegally copied contents are raising serious social problem as internet and multimedia technologies are advancing. Therefore, development of video copy detection system must be settled without delay. In this paper, we propose the hierarchical video copy detection method that estimates similarity using statistical characteristics between original video and manipulated(transformed) copy video. We rank according to luminance value of video to be robust to spacial transformation, and choose similar videos categorized as candidate segments in huge amount of database to reduce processing time and complexity. The copy videos generally insert black area in the edge of the image, so we remove rig black area and decide copy or not by using statistical characteristics of original video and copied video with center part of frame that contains important information of video. Experiment results show that the proposed method has similar keyframe accuracy to reference method, but we use less memory to save feature information than reference's, because the number of keyframes is less 61% than that of reference's. Also, the proposed method detects if the video is copied or not efficiently despite expansive spatial transformations such as blurring, contrast change, zoom in, zoom out, aspect ratio change, and caption insertion.

• Atmosphere
• /
• v.24 no.1
• /
• pp.123-130
• /
• 2014

The automated prediction system for seasonal tropical cyclone (TC) activity is established at the National Typhoon Center of the Korea Meteorological Administration (KMA) to provide effective operation and control of the system for user who lacks knowledge of the system. For automation of the system, two procedures which include subjective decisions by user are performed in advance, and their output data are provided as input data. To provide the capability to understand the operational processes for operational user, the input and output data are summarized with each process, and the directory structure is reconstructed following KMA's standard. We introduce a user interface using namelist input parameters to effectively control operational conditions which is fixed or should be manually set in the previous version of the prediction system. To operationally use early prediction which become available through the automation, its performances are evaluated according to initial condition dates. As a result, high correlations between the observed and predicted TC counts are kept for all track clusters even though advancing the initial condition date from May to January.

• Molecular & Cellular Toxicology
• /
• v.5 no.2
• /
• pp.126-132
• /
• 2009

The usage and types of chemicals are advancing, specializing, large-scaled increasing, and new chemical exposed workers are concerning to occupational disease. The generation of reactive oxygen in the body from carcinogen, mutation and DNA damage in cancer is protected by natural antioxidants (phytochemicals) with antimutagenic effect. There were many reports of ginsenoside Rb$_1$, Rg$_1$ grievances of the genetic mutation to suppress the effect confirm the genetic toxicity test with chromosomal aberration test and the Comet (SCGE) assay confirmed the suppression effect occurring chromosomal DNA damage. We had wanted to evaluate the compatibility and sensitivity between the chromosomal aberration (CA) test and the Comet assay. We used the CA test and Comet assay to evaluate the anti-genotoxicity of ginsenoside Rb$_1$ and Rg$_1$, in CHO-K1 (Chinese hamster ovary fibroblast) cell in vitro, composed negative control (solvent), positive control (benzo[a]pyrene), test group (carcinogen+variety concentration of ginsenoside) group. The positive control was benzo[a]pyrene (50 $\mu$M), well-known carcinogen, and the negative control was the 1 % DMSO solvent. The test group was a variety concentration of ginsenoside Rb$_1$, Rg$_1$ with 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1%, 10%. In chromo-somal aberration test, we measured the number of cells with abnormally structured chromosome. In Comet assay, the Olive tail moment (OTM) and Tail length (TL) values were measured. The ratio of cell proliferation was increased 8.3% in 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1%, 10% Rb$_1$ treated groups, and increased 10.4% in 10$^{-10}$%, 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1% Rg$_1$ treated groups. In the CA test, the number of chromosomal aberration was decreased all the Rb$_1$ and Rg$_1$ treated groups. In the Comet assay, the OTM values were decreased in all the Rb$_1$ and Rg$_1$ treated groups. To evaluate the compatibility between CA and Comet assay, we compared the reducing ratio of chromosomal abnormalities with its OTM values, it was identified the antimutagenicity of ginsenoside, but it was more sensitive the CA test than the Comet assay. Ginsenoside Rb$_1$ and Rg$_1$ significantly decrease the number of cells with chromosomal aberration, and decrease the extent of DNA migration. Therefore, ginsenoside Rb$_1$, Rg$_1$ are thought as an antioxidant phytochemicals to protect mutagenicity. The in vitro Comet assay seems to be less sensitive than the in vitro chromosomal aberration test.

• Archives of Plastic Surgery
• /
• v.32 no.3
• /
• pp.335-342
• /
• 2005

This study was undertaken to investigate possibility of the allogenic type I collagen inducing osteoinduction or osteoconduction at critical sized bone defect in the rabbit. Twenty Newzealand white rabbit, weighted from 2.8 kg to 3.5 kg, were used in this study. The skull was exposed and two bony defects were created with diameter of 10 mm. Group I(n=10), the bony defects was grafted from the other side bone. Group II(n=10), the bony defects was grafted by the allogenic type I collagen with bone morphogenic protein(BMP). Group III(n=10), the bony defects was grafted by the allogenic type I collagen only. Group IV(n=10), the bony defects was lefted with no grafts. The grafted bones and allogenic type I collagen were investigated with radiologic densitometry, histologic analysis and immunohistochemistry after 12 weeks. No major difference was observed in the gross finding between Group I, II, III, but dura mater was exposed in bony defect,the Group IV. The radiologic study demonstrated more bony opacity in the Group I, but the other groups did not demonstrate a significant difference. In the histologic study, grafted bone edge was completely consolidated with original bone in group I and new bone ingrew into the grafted allogenic type I collagen(group II, III),but there is no bone regeneration from the original bony edge in the group IV. The percent of the new bone formation by cross-sectional area was considered statistically significant at a p value of less than 0.05(p<0.05). In the immunohistochemistry study about BMP antibodies, the group IV demonstrated osteogenic activity in front of advancing original bone edge, in which the osteoblast stained strongly for BMP antibodies, but other group does not demonstrated any osteoblastic expression. There was no immunologic rejection. In conclusion, this results do not demonstrate that the allogenic type I collagen is useful for bone substitute, but the characters of the collagen, such as pliability, easy-handling, sponge-like structure, are useful in interpositional bone graft substitutes. The further evaluation of long term results about the resorption, immunologic tissue reaction, response of applied tissue growth factor to the allogenic collagen is needed.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1982.05a
• /
• pp.9.2-9
• /
• 1982

The incidence of decannulation difficulty included tracheal stenosis has markedly increased in recent years because of translaryngeal intubation and tracheostomy although advancing antibiotics and new treatment for these problems. Treatment has always been difficult but in mild cases, a new soft, flexible tracheal T-tube that designed to maintain an adequate tracheal airway as well as to provide support in the reconstructed trachea and in severe cases, transverse resection with subsquent end to end anastomosis has been used in recent years. Authors experienced 2 cases of tracheal stenosis and decannulation difficulty which developed after tracheostomy that was performed due to automobile accident and fall down respectively and using a silicone tracheal T-tube for 3 months good results were obtained. So authors reported with brief review of literatures.

• Korean Journal of Environment and Ecology
• /
• v.2 no.1
• /
• pp.19-36
• /
• 1988

To investigate edge vegetation structure and edge species in Chiak Mountain National Park, field survey was executed from July to September, 1988. Canonpy drip-line type, cantilevered type and advancing type of edge vegetation were observed on site. The relative importance values of major species in each crown layer were changed along distance from edge to forest interior differently by aspect and present tree layer vegetation. Especially light-oriented edge species as codominant species were observed in Pinus densiflora forest interior at south slope and moisture - oriented species as codominant species were observed with light-oriented species in north edge beside torrential stream. No. of species and individuals by crown layer, species diversities and dissimilarities were decreased according to the distance from edge to forest interior, and edge depth was estimated as 15-20m. Dominant species of edge in shrub and ground layer were different by altitude and topographic locations; valley, ridge, summit and edge species at summit were not observed at other area. Floristic similarities between edge vegetations at different environments were affected by altitude, aspect and topographic location. Frequency classes of edge species were different by aspect, altitude and topographic location. Weigela subscssilis showed high frequency class in all environment conditions and Quercus mongolica, Lindera obtusiloba, Symplocos chinensis for, pilosa, weigela subscssilis, Fraxinus rhynchophylla, Actinidia arguta, Rubus crategifolius. Pinus densiflora, Aralia elata etc, were observed as edge species at all environmental conditions, respectively.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.1
• /
• pp.30-34
• /
• 2009

Purpose: Many companies developed a lot of programs with continuous effort for program upgrading. With this acquire superior image quality for the purpose of quick examination and progress in spatial resolution. This study was to obtained clinical usefulness on a appropriate parameter of FWHM for speed and alpha value for superior image quality. Materials and Methods: Gamma camera by Siemens (e.cam) and spatial resolution phantom and four quadrant bar phantom used. Compared for FWHM by changed scan speed 15, 20, 25, 30, 35, 40 cm/min in scatter and non scatter in Onco Flash of spatial resolution phantom. Visual evaluation of count rate and bar phantom image for increased of alpha value of 10% in 0~100%. Results: FWHM by the scan speed was 9.37, 9.40, 9.28, 9.30, 9.31, 9.53 mm in the scatter. Count rate increased alpha value 10% increased. Visual evaluation was suitable to below 30%, Therefore spatial resolution improved on FWHM at the scan speed 25~35 cm/min applying for alpha value 30% in Onco Flash was average 9.3 mm less than FWHM of below 15 cm/min and above 40 cm/min. Conclusion: We found on appropriate parameter to progress of image quality. And there be a useful guideline for you that appropriate scan speed on vary in parameters of reduction on examination time and advancing image quality.

• Journal of Science and Technology Studies
• /
• v.13 no.1
• /
• pp.41-76
• /
• 2013

Based on an analysis of the Japanese animation director Kamiyama Kenji's Ghost in the Shell: Stand Alone Complex series, this paper discusses two important subjects in modern technoscience-cyborg and old age. In fact, age has been an important social and political category in the modern world, along with gender, race, and class. However, age has not been a significant research topic for STS scholars. Even though many of these investigators have extensively explored the complex relationship between gender and technoscience, especially after the publication of Donna Haraway's "Cyborg Manifesto" (1991), few of them have been interested in how age is reconfigured by modern science and technology. If women, as Haraway has claimed, can have a different political and cultural outlook by becoming cyborgs, then, can we expect a similar socio-cultural transformation with regard to the interaction between cyborg and old age? Do the elderly experience lesser age discrimination through the growth of biomedicine and technoscience? Indeed, it is believed that seniors are increasingly becoming cyborgs with advancing age, since their declining bodily functions are consistently replaced and assisted by various biomedical technologies. Does this enable them to overcome ageism and age discrimination as well as their alleged physiological and mental limitations? As an answer to this question, Mike Featherstone has asserted that becoming a cyborg in old age could make the wrinkled skin a mere mask and create diverse new possibilities that were hitherto unavailable to an aging person. Based on my reading of Ghost in the Shell, however, I analyze a more complex set of problems when the senile cyborg is created through the encounter between the elderly and technoscience. I argue that while the senile cyborg could challenge traditional family ideology and nationalism it would leave ageism intact and define a new individualistic life form through a body controlled within the globalized internet and capitalist economy.

• Journal of the Korea Concrete Institute
• /
• v.20 no.6
• /
• pp.721-729
• /
• 2008

The purpose of this study is to investigate the engineering properties of concrete for the early strength development. As a result of reviewing it by establishing each experimental factor and level, the cement had more excellent quality performance in CHC and HESPC than OPC. This study has shown that the PC series admixture was more excellent in side of elapsed time (aging) and early strength development than PNS series admixture. In addition, there was much difference according to the curing temperature, but the early strength development showed the considerable vulnerability in curing temperature below $12^{\circ}C$. To satisfy the strength requirements of 5 MPa/18 hr this study has shown that it needed the curing temperature over $17^{\circ}C$ to the minimum in OPC, over $14^{\circ}C$ in CHC, and over $11^{\circ}C$ in HESPC. On the other hand, as to the strength properties according to W/C, the less W/C was, the more strength development was excellent. If this study is to be used in construction filed on a basis of this result, this researcher is considered as possible of the economic execution of construction by advancing the early strength and by the reduction of construction cost according to shortening construction duration.