• Korean Journal of Materials Research
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• v.13 no.5
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• pp.317-322
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• 2003

Bismuth layered structure ferroelectric thin films, $Bi_4$$Ti_3$$O_{12}$ / (BTO) and Nb-doped BTO (BTN) were prepared on the Pt(111)/Ti/$SiO_2$/Si(100) substrates by a sol-gel route. We investigated the Nb-doping effect on the grain orientation and ferroelectric properties. $Nb^{5＋}$ ion substitution for $Ti^{4＋}$ ion in perovskite layers of BTO decreased the degree of c-axis orientation and increased the remanent polarization (2Pr). The fatigue resistance of Nb-doped BTO thin film was shown to be superior to that of BTO, and the leakage current of Nb-doped BTO thin film was decreased about 1 order of magnitude compared with BTO. The improvement of ferroelectric properties with $Nb^{5＋}$ doping in BTO could be attributed to the changes in space charge densities and grain orientation in the thin film.

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.111-117
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• 1989

Six cigarette brands produced in Korea and U.S.A. were studied to find the effects of relative humidity, moisture sorption time, temperature, and the amounts of water extracts and total sugar in the brands on the equilibrium moisture contents. The equilibrium contents were higher in the domestic brands than foreign ones and the sorption rates of moisture were faster in the domestic cigarettes. The Korean brands with high contents of water extracts and total sugar had higher equilibrium moisture contents in the range of RH 40-80% at $20^{\circ}C$ for 72hours. These are the reasons that Korean brands contain higher ratio of flue-cured tobacco and American brands are blended with higher ratio of Burley tobacco.

• Journal of the Korean earth science society
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• v.33 no.3
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• pp.233-241
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• 2012

Based on the observation of the microwave radiometers at Cheongju, Hapcheon and Daegwallyeong in Korea, the precipitable water vapor and liquid water path have been analyzed for spatio-temporal characteristics. The observed datas have been validated by comparing precipitable water vapor between the microwave radiometer and the radiosonde near the sites. It resulted in the correlation coefficient of more than 0.8 in all three sites. For three regions, the precipitable water vapor shows similar seasonal variation and diurnal cycle, and that amount of precipitable water vapor increases from around 1000 LST and has a maximum value at 1900 LST. On the other hand, the liquid water path of microwave radiometer has regional differences for its seasonal variation, which seems to be caused by the geographical characteristics including the frequent fog and clouds in Daegwallyeong, a high mountain region (834 m from sea level), almost flat land in Chengju, and Sobaek Mountains in Hapcheon that blocks the westerly clouds.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.384-393
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• 2013

In this paper, a design of planar microwave bias-tee using lumped elements was presented. The bias-tee is composed of 2 blocks; DC block and RF choke. For this design of the bias-tee, a wideband capacitor was used for DC block. For a RF choke, a series connection of inductors which have different SRFs is used for a RF choke. In the RF choke, a series connection of resistor and capacitor was added in shunt to eliminate a loss from a series resonance. The designed bias-tee was implemented by using 1608 SMT chip components. The fabricated bias-tee was measured using Anritsu 3680K fixture which enables to remove an effect of a connector. The fabricated bias-tee presented -15 dB of return loss and -1.5 dB insertion loss at 10 MHz~18 GHz.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.633-638
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• 2006

We investigated the importance and efficiency of active and passive exploration on the recognition of objects in a variety of virtual environments (VEs). In this study, 54 participants (19 males and 35 females) were randomly allocated into one of two navigation conditions (active and passive navigation). The 3D visual display was presented through HMD and participants used joysticks to navigate VEs. The VEs consisted of exploring four rooms (library, office, lounge, and conference room), each of which had 15 objects. 'Active navigation' was performed by allowing participants to self-pace and control their own navigation within a predetermined time limitation for each room. 'Passive navigation' was conducted by forced navigation of the four rooms in random order. Total navigation duration and objects for both navigations were identical. After navigating VEs, participants were asked to recognize the objects that had been in the four rooms. Recognition for objects was measured by response time and the percentage of correct, false, hit, and miss responses. Those in the active navigation condition had a significantly higher percentage of hit responses (t (52) = 4.000 p < 0.01), and a significantly lower percentage of miss responses (t (52) = -3.763, p < 0.01) in object recognition than those in the passive condition. These results suggest that active navigation plays an important role in spatial cognition as well as providing a better explanation about the efficiency of learning in a 3D-based program.

• Atmosphere
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• v.21 no.3
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• pp.229-241
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• 2011

The continuous urbanizations by a rapid economic growth and a steady increase in population are expected to have a possible impact on meteorology in the downwind region. Long-term (1972~2007) trends of precipitation have been examined in the mid-Korean peninsula for the westerly condition only, along with the sensitivity simulations for a golden day (11 February 2009). During the long-term period, both precipitation amount (PA) and frequency (PF) in the downwind region (Chuncheon, Wonju, Hongcheon) of urban area significantly increased for the westerly and light precipitation ($PA{\leq}1mm\;d^{-1}$) cases, whereas PA and PF in the mountainous region (Daegwallyeong) decreased. The enhancement ratio of PA and PF for the downwind region vs. urban region remarkably increased, which implies a possible urbanization effect on downwind precipitation. In addition, the WRF simulation applied for one golden day demonstrates enhanced updraft and its associated convergence in the downwind area (about 60 km), leading to an increase in the cloud mixing ratio. The sensitivity experiments with the change in surface roughness demonstrates a slight increase in cloud water mixing ratio but a negligible effect on precipitation in the upwind region, whereas those with the change in heat source represents the distinctive convergence and its associated updraft in the downwind region but a decrease in liquid water, which may be attributable to the evaporation of cloud droplet by atmospheric heating induced by an increase in an anthropogenic heat. In spite of limitations in the observation-based analysis and one-day simulation, the current result could provide an evidence of the effect of urbanization on the light precipitation in the downwind region.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.3
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• pp.85-91
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• 2002

To investigate the agricultural material application possibility of the compost made by the fermenting tank. We evaluate the stability fertility of the compost In evaluation of the stability of the compost, In germination index of test, germination test of lettuce of little resistibility not germinated wholly, in the radish of resistibility, both Shinco and TM-101 is showed 61%, 55% of germination rate, length of root not showed wholly. In stability fertility of the compost, early growth of radish in a little treatment applied was superior to other treatments except for TM-101 treatment, but the latter growth of those was showed opposite result. In evaluation of the fertility of compost, Primary growth of lettuce was superior in treatment applied 1.5t/10a, the latter growth of those was superior in treatment applied 3t/10a.

• Journal of Information Management
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• v.41 no.1
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• pp.173-200
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• 2010

National construction project for SOC(Social Overhead Capital) is led by the government and invested high cost and all capabilities for long times. In general case the life times of SOC facilities are permanently. According to the long life time of the facilities documents and records of national projects are also retained permanently. Consistent classification systems are required to operation and maintenance of the facilities efficiently and to support the organic co-works for several Stakeholders. Therefore the classification of national construction projects are based on WBS of the project. WBS is the hierarchy structure that established and developed in project management project management methodology to produce deliverables of the projects. As a result, this study provides a prospect of project records classification systems in the 21st Century.

• The Journal of Korean Medicine
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• v.32 no.4
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• pp.149-158
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• 2011

Object: Any medication can have the risk of liver damage. To prevent this risk, liver function tests should be monitored carefully during every course of medication. This paper is a psoriasis case report on liver damage related to Scutellaria Radix medication. Shown by this case, herbal medicine has the possibility of liver damage, too. Therefore it should be carefully used under the direction of Oriental Medical Doctors who specialize in it. The purpose of this case report is to suggest this, and that more cases of liver damage related to herbal medicine should be reported. Methods: To monitor the medication's effect on the liver, liver function was evaluated during medications. Reflotron plus was used to evaluate AST and ALT by analyzing peripheral blood. Results: By this test, a case was identified as liver damage caused by a medication including Scutellaria Radix. Conclusion: This case suggests that Scutellaria Radix medication caused liver damage in a certain patient. Therefore, to prevent liver damage related to Scutellaria Radix, doctors should monitor patient's liver function regularly.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.61-71
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• 1995

This study is concerned with the assessment of the possibility of alum sludge composting, as well as changes of some chemical properties during composting. Alum sludge was mixed in different proportions, which are 0%, 25%, 35% and 45%, respectively, with a sewage sludge and sawdust mixture. The final mixtures to be composted are placed on static piles constructed with a perforated aeration pipe on the ground, and composted for more than 50 days. During the composting of some alum sludge treatments, there was not notable difference in changes of pH, C/N ratio, and content of several minerals among the alum sludge treatments, while changes of pile temperatures and CEC were significant and these remarkable differences in related to the pile temperatures and CEC seem suitable for the evaluation of alum sludge maturity. Also, the results suggested that the proper mixing ratio of alum sludge for composting was 25% level.