• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.1-14
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• 2015

In case of a gas turbine engine for supersonic operation, the engine have a wide range of operating inlet mass flow rate and required high performance such as thrust and fuel consumption. Therefore, variable system and its optimal control logic are essentially needed. In this work, a method for performance prediction of a gas turbine engine with variable system compressor and its control scheme were developed. Conceptual design of compact acuation system for the operation of the variable system was also conducted. The performance of a low-bypass ratio mixed flow turbofan engine was analyzed, and it was observed that the surge margin of the engine is improved at off-design condition by applying the control scheme.

• Korean Journal of Materials Research
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• v.3 no.5
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• pp.459-465
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• 1993

By making the inter-metal PECVD $SiO_2$ as a Si rich oxide under the SOG, the hydrogen and water related diffusants could be captured a t SI dangling bonds. This gettering process was known to prevent the device characteristics degradations related to the H, $H_20$. The basic characteristics of Si rich oxide have been studied according to changing high/low frequency power and $SiH_4/N_2O$ gas flow ratio in PECVD. As increase in low frequency power, deposition rate decreased but K.I. and compressive stress increased. Decrease of the water peaks of FTIR spectra at the wave number range of 3300~3800$\textrm{cm}^{-1}$' also indicated that intensty the films were densified. As increase in SiH, gas flow rate, deposition rate, R.I. and etch rate increased while compressive stress decreased. F'TIK spectra showed that peak intensity corresponding to Si-0-Si stretching vibration decreased and shifted to the lower wave numbers. But AES showed that Si dangl~ng bonds were increased as a result of lower Si:O(l: 1.23) ratlo inthe Si rich oxide as compared to Si : O(1 : 1.98) ratio of usual oxide.

• Archives of design research
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• v.19 no.2 s.64
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• pp.229-240
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• 2006

It is very important issue in information design to improve information efficiency by adapting interesting factors in changing circumstance of information communication. The concept of infotainment is utilized in designing information contents in a way of combining entertainment factors with information itself based on various media and representation technologies. The information arousing user's attention, which includes interesting factors, is persuasive message comppared to the informative message conveying only information itself. The reason why infotainment is persuasive is because it makes the user absorb deeply in the information during the process of understanding by sensorial stimuli, cognitive interest, and situational interest. The sensorial stimuli originates from the expression elements of information design. The cognitive interest from the user's intellectual activities has a try to overcome mental block when user confronts with the redundant expression in the manner of unexpectedness and inharmony. The situational interest originates from user's optimum experience by the flow of satisfaction. Therefore, the attribute of infotainment is defined with the stimuli, the redundancy, and user's satisfaction. Its design elements consist of physical factors, organizational factors, and psychological factors. The physical factors through sensorial stimuli are utilized by visual manipulation such as visual analogy or visual pun, multimedia, and moving expression. The organizational factors through redundant expression bring user's imagination by adapting storytelling, event, and interaction in the process of understanding information. The psychological factors through expression of entertainment interests such as humor, play, and game give users psychological satisfaction with the flow. In conclusion the concept of infotainment can be adapted when the design factors should be integrated with its attributes, or the conveying information should go well with its purpose and characteristics.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.2
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• pp.78-88
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• 2012

Objectives: Paeonia japonica has been widely used for gynecopathy and analgesic effects in Korean Traditional Medicine. The aim of the present study is to determine the antioxidant effect of Paeonia japonica extracts(PJE) by using mouse embryonic fibroblast cells(MEF cells). Methods: We evaluated Radical Scavenging Activity of PJE by the DPPH assay. Protective effect of the PJE on the hydrogen peroxide($H_2O_2$) induced oxidative damage of MEF cells was analyzed by the MTT assay. The Morphological changes of MEF cells induced by P. japonica, $H_2O_2$ and P. japonica+$H_2O_2$ was evaluated by DAPI staining. And effect of PJE on the rate of apoptosis in MEF cells was measured using flow cytometry with Annexin V-FITC and PI double staining. Results: We observed that PJE contain significant DPPH radical scavenging activity. Cell viability of oxidative damaged cells treated with various concentrations of $H_2O_2$ was increased by treatment with PJE. Flow cytometric analysis of the cells treated with $H_2O_2$ in the absence or presence of PJE showed that the crumbled G1 peak was accumulated by the treatment with $H_2O_2$ alone, but restored by addition of PJE. Portion of cells that undergo apoptosis mediated by oxidative stress was decreased by treatment of PJE. The nuclear fragmentation occurred in the oxidative damaged MEF cells was also decreased by PJE treatment. Conclusions: Taken together, our results suggest that PJE exhibits significant antioxidant activity and functions to inhibit cell death mediated by oxidative damage induced apoptotic pathways.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.426-433
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• 2019

Objectives: Zooplankton communities play important roles in aquatic ecosystems as secondary producers that graze on phytoplankton and in turn are preyed upon by planktivorous and juvenile fish. They can shift their distribution, species composition, and abundance in response to environmental changes. Therefore zooplankton communities are important for understanding the energy flow in aquatic ecosystems and can be valuable indicators of environmental conditions. However, zooplankton in streams are still not well-studied, especially in northern Gyeonggi-do Province. This study aims to investigate the zooplankton communities in major streams in northern Gyeonggi-do Province. Methods: Zooplankton is important in the nutrient cycle and energy flow of aquatic ecosystems. Therefore, we surveyed zooplankton and measured temperature, DO, BOD, COD, T-N, T-P, and Chl-a in major streams (Sincheon, Gongneungcheon, Wangsukcheon, and Gapyeongcheon Streams) and stagnant water (Gomoji Reservoir). Results: The water quality in Gapyeongcheon Stream was the highest grade, while that of Gomoji Reservoir was mesoeutrophic and eutrophic during the research period. In the zooplankton community, Nauplius, Rotaria, and Monostyla spp. were dominant in Sincheon, Gongneungcheon, and Wangsukcheon Streams, and the dominance index was also high. In the case of Gapyeongcheon Stream, it was found that water quality and aquatic ecosystem health were good, and the lowest dominance index reflected this. In Gomoji Reservoir, Polyarthra spp., Nauplius, and Bosmina longirostris, which can be easily observed as eutrophication progresses, showed a high dominance rate. Therefore, it is necessary to monitor the progress of eutrophication in further research. Conclusions: We collected data on the zooplankton communities in streams and investigated their characteristics. As a result, specific species were found to be dominant at each survey sites and some of them are known to be observed as eutrophication progresses. Therefore, we should investigate the zooplankton community of streams around us and apply ecological stream management.

• Journal of the Korean earth science society
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• v.35 no.6
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• pp.439-466
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• 2014

Since the unification of the diverse oceanic current maps of the East Sea in secondary school science textbooks has recently been accomplished, there have been increasing requirements for the production of a current map of the Yellow Sea (YS) and the East China Sea (ECS). This study, as its first attempt, facilitated the prospective production process of the unified oceanic current maps in YS and ECS by analyzing the maps of scientific articles and those of the present textbooks as of 2014. First of all, the analogue current maps of the textbooks and scientific articles were digitalized to retrieve the characteristics of current maps quantitatively and to make intercomparison of the maps. The currents of both YS and ECS such as the Kuroshio Current, the Taiwan Warm Current, the Tsushima Warm Current, the Yellow Sea Warm Current, the Chinese Coastal Current, the Korea Coastal Current, and the Changjiang River Flow were selected and analyzed. We made 18 items to investigate the paths of the currents. Analyses of the oceanic current maps of secondary school science textbooks and scientific articles with respect to the selected criteria revealed that the current maps of the textbooks were considerably different from the up-to-date knowledge of the current maps acquired from the scientific articles. In addition, since the currents of YS and ECS have strong seasonality, we suggest that they should be presented with at least two current maps for summer and winter in the textbooks, which may go through active discussions among experts.

• Korean Journal of Materials Research
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• v.3 no.1
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• pp.12-18
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• 1993

Abstract The effect of the film stress on the thermal stability of TiSi, films under the dielectric overcoat was investigated. TiS$i_2$ films with the sheet resistance of 1.2 ohm/sq. were produced by a solid-state reaction between sputtered Ti film and single-crystalline Si in an RTA (rapid thermal anneal) machine. Dielectric overcoats such as the USG (Undoped Silicate Glass, Si$O_2$) film and the PE-SiN(S$i_3$$N_4$) film were deposited by AP-CVD and PE-CVD, respectively, on the TiS$i_2$ film. The thermal stability of the TiSi, film was evaluated by changes in the sheet resistance, film stress and microstructure after furnace anneals at 90$0^{\circ}C$. Agglomeration of the TiSi2 film high temperatures results in the increase of sheet resistance and the decrease of tensile stress of TiSi, film. The stress level of the TiSi" PE-SiN and ~SG films at 90$0^{\circ}C$C was 1.3${\times}{10^{9}}$, 1.25 ${\times}{10^{10}}$, 2.26 ${\times}{10^{10}}$ dyne/c$m^2$ in tensile, respectively. Dielectric films deposited by CVD on TiSi, was effective on preventing agglomeration of TiSi,. The PE-SiN film mproved the thermal stability of TiSi, more effectively than the AP-CVD USG film. It is considered that agglomeration of the TiS$i_2$ film under the stress of dielectric overcoat at high temperature can be caused by a diffusional flow of atom called Nabarro-Herring microcreep.reep.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.6
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• pp.48-56
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• 2008

This study provides to car driver with car exhaust gas and sensor information which are car trouble code in engine and many sensors when the car has some problems. This is to provide car manager with many information of car sensors when we go to vehicle maintenance. For example, information of engine RPM, fuel system, intake air temperature, air flow sensors and oxygen sensors can provide to owner or garage, and also add to multimedia system for mp3 files and video files. This system consists of embedded linux system of low power while driving the car which uses OBD-II protocols and zigbee communication interface from CAN communication of car system to self-diagnosis embedded system of car. Finally, low power embedded system has a lot of application and OBD-II protocols for embedded linux system and CAN communication which get sensor informations of car control sensor system while driving the car.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.146-152
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• 2001

Purpose : To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. Materials and Methods : 8-week old male mice, C57B1/6J were given whole body $\gamma-radiation$ with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins Bl, Dl, E and cdk2, cdk4, $p34^{cdc2}$ were analysed by Western blotting. Cell cycle was analysed by Flow cytometry. Results : The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is $24.0{\pm}0.25$ (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-Gl, G2-M and S phase in the cell cycle does not specific changes by time. Conclusion : In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle ofter better understanding of radiation response of noraml brain tissue.

• Journal of the Korean Society of Costume
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• v.53 no.2
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• pp.153-169
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• 2003

I think that apparel attaches importance to the degree of satisfaction of visual expression in one ornamental culture in which it is clothed on human body. whereas a tattoo attaches more importance to part of the expression of one's own identity in the same context. However. modern tattooing act was highlighted only as an element of act which was negative in the purpose and the degree of taste or which assumed the grotesque meaning of a particular group. away from pure concepts such as simple ornament or an amulet according to the flow of the world. A tattoo is gradually being seen as one of avant-garde methods of art again these days, and TATTOO LOOK is being popularized as street fashion as an effective method of one's own satisfied desires and peculiar expression of personality. I have got the following conclusions as the result of having studied on a tattoo which is establishing itself as another plastic art that is matchable with the fashion of dress and its ornaments in which human incessant instinctive desire for the ornament of body has been beyond nostalgia for the past and simple ornament which were pure in up-to-date modern society First, a tattoo is of personality. In that it solidifies one's own personality of another side by being transformed, one's own attraction can be transferred to a fashion tattoo with which one can emit one's own personality. Secondly. a tattoo is fashion. As a new body ornament called transformation by a tattoo was emerging, the fashionableness owned by a tattoo had in its area ample room for the fashionableness with which it can coexist with the culture of dress and its ornaments. Thirdly. a tattoo is popularized. TATTOO LOOK in which one's own satisfied desires and the expression of personality are properly applied is being recently transmitted easily everywhere in the world and popularized as street fashion. Fourthly, a tattoo is not depraved art. It's because of the point that a tattoo which had been recognized only as a decadent expression in which avant-garde elements of unknown nationality appeared mixed showed the possibility that it could establish itself as fashion art. If we go on studying and complementing the problems of individual sides about a tattoo also in the future, the infinite fashionableness for the elements called personality. sense and emotion owned by a tattoo suggested ample possibility as future industry to be highlighted.