• Publications of The Korean Astronomical Society
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• v.15 no.spc2
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• pp.21-25
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• 2000

The ionosphere, the atmosphere of the earth ionized by solar radiations, has been strongly varied with solar activity. The ionosphere varies with the solar cycle, the seasons, the latitudes and during any given day. Radio wave propagation through or in the ionosphere is affected by ionospheric condition so that one needs to consider its effects on operating communication systems normally. For examples, sporadic E may form at any time. It occurs at altitudes between 90 to 140 km (in the E region), and may be spread over a large area or be confined to a small region. Sometimes the sporadic E layer works as a mirror so that the communication signal does not reach the receiver. And radiation from the Sun during large solar flares causes increased ionization in the D region which results in greater absorption of HF radio waves. This phenomenon is called short wave fade-outs. If the flare is large enough, the whole of the HF spectrum can be rendered unusable for a period of time. Due to events on the Sun, sometimes the Earth's magnetic field becomes disturbed. The geomagnetic field and the ionosphere are linked in complex ways and a disturbance in the geomagnetic field can often cause a disturbance in the F region of the ionosphere. An enhancement will not usually concern the HF communicator, but the depression may cause frequencies normally used for communication to be too high with the result that the wave penetrates the ionosphere. Ionospheric storms can occur throughout the solar cycle and are related to coronal mass ejections (CMEs) and coronal holes on the Sun. Except the above mentioned phenomena, there are a lot of things to affect the radio communication. Nowadays, radio technique for probing the terrestrial ionosphere has a tendency to use satellite system such as GPS. To get more accurate information about the variation of the ionospheric electron density, a TEC measurement system is necessary so RRL will operate the system in the near future.

• Journal of Life Science
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• v.14 no.3
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• pp.429-434
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• 2004

Levansucrase gene (levU) from Zymomonas mobilis was subcloned downstream of GALl promoter in pYES 2.0 and pYInu-AT [GALl0 promoter＋exoinulinase signal sequence of Kluyveromyces marxianus], resulting pYES-levU and pYInu-levU, respectively. The two expression plasmids were introduced into an invertase-deficient strain, Saccharomyces cerevisiae SEY2102, and then transformants showing high activity of levansucrase were selected. When each yeast transformants was cultivated in medium containing galactose, the extracellular and intracellular activities of levansucrase reached about 7.17 U/㎖ with the strain harboring pYES-levU and 6.61 U/㎖ with the strain harboring pYInu-levU. It was found that about 50% of levansucrase were detected in the medium and periplasmic space, and exoinulinase signal sequence didn't enhance the secretion efficiency. Furthermore, the recombinant levansucrase expressed in yeast seems to be produced as a hyper-glycosylated form.

• Journal of Korea Game Society
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• v.15 no.6
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• pp.141-148
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• 2015

Most current games are composed of simple operations without a user's actual movements. because they are made up of only virtual space. For that reason, many side effects arise on a user's body and mind. The Alternative Reality Game(ARG) is new game genre that has an effect to mitigate side effects caused by activity on a virtual space. This new kind of game genre can be instrumental role in creating a greater social intimacy and a higher tendency to cooperate that potentially reaches beyond the game context. In this paper, we suggest a real implementation of ARG using mobile devices and NFC tags. In addition, a noble editor for creating an ARG and a game launcher based on mobile device are suggested.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.58-63
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• 2004

Purpose: The purpose of this study is to evaluate the effectiveness of low-dose gabapentin for interdigital neuroma. Metrials and Methods: Between April 2000 and June 2003, 32 patients (39 feet) with interdigital neuroma were treated with using low-dose gabapentin. Two of the 32 patients were male, and thirty were female, and the average age was 47.4 years. The follow-up was 6 to 44months (mean 15.1 months). All cases were diagnosed by physical examination and ultrasonography or MRI. Low-dose gabapentin (300-600 mg) was prescribed and shoe modification was recommended. The patients were evaluated through questionnaire. Results: Neuroma was found in twenty one cases at the third intermetatarsal space, and thirteen at the second intermetatarsal space. The sensitivity of ultrasonography was 96% and that of MRI was 79%. Overall satisfaction was rated as excellent or good by 18 cases (57%). Average pain relief ratio was 50.3%, and in 14 cases, more than 80% of pain relief was noted. Nine (28%) of 32 patients showed they had no activity restrictions, such as daily activities or work, whereas 8 (25%) had mild restrictions and 15 (47%) had major restrictions. Twelve of 15 patient with major restrictions had been treated operatively (neurectomy; 10 cases, decompression; 2 cases). One case had gastrointestinal problem. Conclusion: Low-dose gabapentin for interdigital neuroma was one of the effective conservative treatments. The operation may be preserved for patient with the persist symptoms, nevertheless the conservative treatments and use of low-dose gabapentin.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.43-53
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• 2015

As part of alternative of elderly problems in the future super-aging society, this study aims to extract an improvement plan of interior environment design of Seoul-type day care centers to expand in future by observing day care centers as medical and healing environments, from the perspective of user experience. For this study, after selecting major activity areas of representative cases of Seoul-type day care centers, user behaviors in the space were observed and 4 seniors of baby-boom generation who are potential uses were chosen as personas by reflecting characteristics of healthy elderly, physical aging, mental aging and infirm elderly, from the perspective of user experience. Based on previous studies on healing environments, these characteristics and demands of personas were classified into environmental aspects, physical aspects and mental aspects to extract an improvement plan. The study results are as follows. First, interior environment design reflecting persona characteristics helps the elderly adapt to the environment and provides a comfortable environment like home for stability, treatment and recovery of memory. Second, interior environment design reflecting persona characteristics helps psychological healing through light entering the large windows and natural environment elements. Third, for interior environment design reflecting persona characteristics, finish materials with bright and soft colors should be used to change the images of facilities positively. Fourth, spatial composition should be remedied through division of space and built-in furniture depending on the needs of users for loitering of extra time and programs.

• Korean Institute of Interior Design Journal
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• v.26 no.4
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• pp.75-83
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• 2017

The cultural tendency based on sharing and cooperation, which has recently been a hot issue, accelerates throughout the world. This study began with a perception that a sharing culture is inherent in urban public spaces. This study aims to conduct a theoretical study of the sharing culture and to analyze the characteristics of the design composition of public spaces. This study selected squares in 16 European cities as cases for analysis. The results are summarized as follows:1)To analyze the design characteristics of public spaces in which a sharing culture is inherent, this study drew the shape and type of planes and sharing elements such as accessibility, symbolism and activity with the squares in the cases. 2)The shape of planes in the squares in the cases has been formed in close relations with the historic meaning and events of the area and the process of the construction of buildings surrounding the square. The squares in the cases were classified into seven plane types, and these squares have developmentally contributed to the formation of a sharing culture as a place for free participation and communication concerning social issues. 3)In the squares in the cases, the weight of road-centered access appears high, and in terms of the construction of human-friendly / environment-friendly infrastructure in the city or judging from the trend of the recent increase of pedestrian-centered plans for public space, it is judged that approaches with a high utilization rate of sidewalk or public transportation would be desirable. 4)Symbolic elements of the square become a device by which citizens can share the historic symbolism, along with artistic inspiration. In addition, by serving as an observatory from which people can take a view of the landscape of the city, it allows visual sharing of the entire city as well as the square. 5)A square is common pool resources in the community, and it is necessary to vitalize that in a direction of increasing the possibility of sharing, through the characteristics and methods of the composition of public design.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1977-1983
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• 2000

SCR(selective catalytic reduction) pilot plant for reduction of the nitrogen oxides using diesel oil as a reductant was installed at the NG(natural gas) fired combined cycle and the activity of Pt(0.3%)/Zeolite catalyst was studied in real flue gas condition according to the amount of reductant. reaction temperature and space velocity. NOx conversion gradually increased with increasing the diesel oil concentration up to C/N ratio 5.5(C/N ratio: the ratio of the number of carbon atom to the number of NOx molecules included in the flue gas). Increasing the reaction temperature. NOx conversion increased and reached a maximum conversion of 50% at $190^{\circ}C$. NOx conversion did not changed with increasing the space velocity up to 18,500/hr and then gradually decreased. These results reveal the potential for diesel oil as a reductant for de-NOx SCR process.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.1
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• pp.48-61
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• 2000

Korea Aerospace Research Institute (KARI) have gained experience with Helicopter Vibration Health Monitoring (VHM) System technology with the help of UK GKN-WHL. GKN-WHL have had many years of experience with the research and development of vibration analysis techniques to improve the health monitoring of helicopter transmissions. This activity was targeted at transmission rig testing at first, but the techniques have been progressively developed where they are now used as a part of integrated Health and Usage Monitoring (HUM) systems on many types of in-service and new helicopters. The technique development process has been considerably aided by an ever expanding database of transmission monitoring experience from both the rig testing and aircraft operations. This experience covers a wide range of failure types from naturally occurring faults to crack propagation studies and covering a wide range of transmission configurations. Primarily based on accelerometer signals GKN-WHL's vibration analysis methods have also been applied to a variety of other sensor types. The transition from an experimental environment to operational VHM systems has been a lengthy process, there being a need to demonstrate technique reliability as well as effectiveness to both regulatory (Airworthiness Authority) and commercial organizations. Another important feature of this process has been the development of close relationships with a number of VHM system hardware and software suppliers. Such an experienced GKN-WHL provides various raw vibration data which was acquired from transmission ground test rig and allow KARI to develop it's own analysis program. KARI made a program and then analyzed the data to coma pre with the results of GKN-WHL. The KARI's results both time domain signals and statistical values show comparable to GKN's.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.60-66
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• 2004

The cycloinulooligosaccharide fructanotransferase(CFTase) gene (cft) from Paenibacillus polymyxa was subcloned into the E. coli-yeast shuttle vector, pYES2.0 (GALI promoter). The constructed plasmid, pYGCFT (9.9 kb) was introduced into S. cerevisiae SEY2102 cell and then the yeast transformant was selected on the synthetic defined media lacking uracil Based on the cyclofructan(CF) spots on thin-layer chromatogram, the gene under the control of GALI promoter was successfully expressed in the yeast transformant. The recombinant CFTase was not secreted into the medium and was predominantly localized in the periplasmic space. CF was started to be produced after 3h of enzymatic reaction with inulin. The pH and temperature optimum for the CF production from inulin was pH 8.0 and 45$^{\circ}C$, respectively. Enzyme activity was stably maintained up to the pH of 10.0. The examination of the inulin sources revealed that a dahlia tuber and Jerusalem artichoke were the best for the production of CF.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.4
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• pp.377-386
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• 2015

DubaiSat-2 is the first satellite developed in Korea equipped with a hall-effect thruster. In this paper, the performance of the DubaiSat-2 hall-effect thruster is verified by analyzing the orbit information of DubaiSat-2. The preparation and performance of orbit operations during 8 months after launch (2013.11.21., UTC) is emphasized and the effects of solar activity on orbit evolution is analyzed. In particular, the hall-effect thruster's thrust is estimated by analyzing difference between observed orbit evolution and predicted orbit. As a result, the estimated thrust is similar to the ground experiment result of 11 mN. The summarized result in this paper would be important reference to improve the stability and effectiveness of satellite operation during the early operation and normal mission lifetime in case of low Earth orbit satellites.