• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.8 s.111
• /
• pp.739-745
• /
• 2006

This paper presents a method to control group delay tine using a resonance circuit. The group delay time adjuster(GDTA) that can control signal group delay time comprises a variable capacitance and a variable equivalent inductor. These are coupled in parallel at a node and also controlled by two bias voltages separately, A variable equivalent inductor is realized a transmission line terminated a variable capacitor. Group delay time can be controlled by change of capacitance and inductance, but the resonating frequency is fixed. When the proposed GDTA is fabricated on RFID Korean frequency band$(908.5{\sim}914 MHz)$, a group delay variation is obtained about 3 ns.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.3
• /
• pp.311-320
• /
• 2008

In this paper, a new variable active inductor using a conventional grounded active inductor with feedback variable LC-resonator is proposed. The grounded active inductor is realized by the gyrator-C topology and the variable LC-resonator is realized by the low-Q spiral inductor and varactor. This variable LC-resonator can compensate the degradation of Q-factor due to parasitic capacitance of a transistor, and the frequency range with high Q-factor is adjustable by resonance frequency adjustment of LC-resonator. The fabricated variable active inductor with Magnachip $0.18{\mu}m$ CMOS process shows that high-Q frequency range can be adjusted according to varactor control voltage from 4.66 GHz to 5.45 GHz and Q-factor is higher than 50 in the operating frequency ranges. The measured inductance at 4.9GHz can be controlled from 4.12 nH to 5.97 nH by control voltage.

• Journal of the Korean Society of Costume
• /
• v.53 no.4
• /
• pp.131-148
• /
• 2003

Mural Painting of Koguryo Dynasty. root of Korean traditional pattern. has 5 types of pattern in its 24tombs: Fire pattern. Sun . Moon pattern, Flying angel pattern. Hill.Tree pattern, Holy animal bird Pattern. These patterns had developed specially in 3 regions that are Hwanghae-region, Pyongan-region, Jipan-region. from 4th-7th Century. A lot of fire pattern has found at Pyongan-region in 5th century. The ceiling right above 'Dori' frequently had the pattern. The pattern is organized in 'Kyoho' method. The sun.moon pattern was shown in Pyongan-region in 5th century. '3-leg bird'. representative of sun, and frog, representative of moon. were drawn in the pattern in 6th century, rabbit was added with frog in the pattern. Flying angel pattern had found most in Jipan region in 5th century. The pattern was not found in 4th century. Two types of the pattern are angels playing $$\mu$ical instruments and angels preying. The hill tree pattern was simple, antique, and immature in the beginning. the pattern had developed with real description as a landscape picture after the beginning. this pattern has been categorized as a landscape painting. Holy animal and bird patternn had placed in supporting rock between ceiling and floor with the mean of protection in after life These pattern, which were previously influenced by Chines culture, were developed with a base of Koguryo own tradition and supported establishment of a characterized Koguryo Cloture. This study will be a basic document for modern fashion industry of 21 century.

• Progress in Medical Physics
• /
• v.8 no.2
• /
• pp.35-43
• /
• 1997

The knowledge of x-ray spectra is highly desirable in some investigation involves the differential penetrating power and absorption coefficient correction of various photon beam. The transmission data were obtained from the 80 kVp and 120 kVp of CT x-ray beam with the aluminium filter which is designed in a 30 cm of diameter and pipe-typed filter was prepared from 5.0 mm upto 92.3 mm of thickness. To obtain the reconstructed spectra of CT x-ray, the investigator used the iterative numerical analysis which has been extended to include the tungsten characteristics from experimental transmission data with energy interval of 2 keV. Comparison of the calculated transmission data from the reconstructed spectra with that of measurement shows good agreement in both 80 kVp and 120 kVp x-ray beams. This numerical analysis based on iteratively calculation of fractional exposure per energy interval shows the high potential of usefulness of determination the x-ray spectra from the attenuated beam in diagnostic energy range.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.6
• /
• pp.1157-1163
• /
• 2002

This experimental research has been done to study the effects of Gmibojungikgi-tang(GBJIKT) on the anti-allergic reaction. We found the several important results from the research which has been performed by two experiments toward immediately type and delayed type in order to study the effects of GBJIKT on hypersensitivity response to mice. The results obtained from our research are as following: The survival rate of one group to which we injected only the compound 48/80 is almost 0% according to its density and timing test. In the other hand, the survival rates of the other group to which we injected both of the compound 48/80 and GBJIKT are 10%, 10%, 20%, 30%, 20%, and 40% according to 0.025, 0.05, 0.1, 0.25 0.5 and 1(mg/g) of compound 48/80. Time dependency test also shows the 0% survival rates in 5 and 10 minutes. GBJIKT revealed the significantly inhibitory effect on Compound 48/80 induced Mast cell degranulation. GBJIKT showed the significantly inhibitory effect in the delayed type hypersensitivity response to picry1 chloride GBJIKT showed the significantly inhibitory effect in the delayed type hypersensitivity response to sheep red blood cell. Our research provides the important evidence that GBJIKT is benificial to the prevention and treatment of allergy related diseases.

• Journal of the Korean Magnetics Society
• /
• v.6 no.4
• /
• pp.211-217
• /
• 1996

The effects of Al addition to Fe-B-Nb-Cu alloy for improving the high-frequency magnetic properties and the magnetic properties of ultrathin $Fe_{78}Al_{4}Nb_{5}B_{12}Cu_{1}$ nanocrystalline alloy ribbons with the thickness less than $10\;\mu\textrm{m}$ were investigated. It was found that the effective permeability at frequencies over- 100 kHz was very high and the core loss was very low for the composition $Fe_{78}Al_{4}Nb_{5}B_{12}Cu_{1}$ alloy. Moreover, the reduction of the ribbon thickness below $10\;\mu\textrm{m}$ was very effective in improving their permeability and the core loss characteristics up to the MHz frequency range. The values of effective permeability at 1 MHz and core loss at 0.2 T, 1 MHz were 5,000 and 1.4 kW/kg, respectively. It was considered that these results were due to far refined $\alpha-Fe$ phase structure with grain size less than 10 nm and domain structure modification.

• Journal of the Korean Magnetics Society
• /
• v.6 no.4
• /
• pp.218-224
• /
• 1996

The magnetic properties and crystallization behaviors of $Fe_{83-x}Al_{x}Nb_{5}B_{12}(X=1~5at%)$ alloys were investigated. The $Fe_{80}Al_{3}Nb_{5}B_{12}$ alloy was developed a very good soft magnetic material with ultra-fine grain structure in Fe-Al-Nb-B system alloys. When 1 at% of Cu was added in Fe-Al-Nb-B alloy, the soft magnetic properties were found to improve significantly through the reduction of the grain size upto about 6~7 nm at $450^{\circ}C$. The magnetic properties of the $Fe_{79}Al_{3}Nb_{5}B_{12}Cu_{1}$ alloy were as follows : ${\mu}_{eff}(1\;kHz)=26,000,\;B_{10}=1.45\;T,\;H_{c}=25\;mOe,\;P_{c}(100\;kHz,\;0.2\;T)=55\;W/kg$, respectively.

• Journal of the Korean Magnetics Society
• /
• v.13 no.3
• /
• pp.91-96
• /
• 2003

Cross-geometrical Cr/Co/Al-Ox/Co/Ni-Fe tunnel junctions were fabricated by magnetron sputtering. To form an insulating layer, The Al layer was oxidized in an atmosphere of oxygen-argon mixture at low power after deposition. To enhance the coercivity of the bottom Co layer, The Cr seed layer was deposited on the glass and it led to increase in coercivity. The coercivity increase is due to the increase of roughness through the Cr thickness. In over oxidation time, the oxidation of Co bottom layer and flat interface of insulator can increase the bottom Co coercivity. But TMR ratio gradually decrease. TMR ratio is relevant with Cr thickness, insulator thickness, and oxidation time. The maximum TMR ratio was 14% at room temperature and the TMR ratio was decreased to half at 0.51 V.

• Health Policy and Management
• /
• v.17 no.2
• /
• pp.52-67
• /
• 2007

Korean government is preparing the long-term care financing and delivery system in order to cope with rapid population aging. The system should be designed to provide demented patients with an appropriate services that the patients want to take, and considered to be necessary for them. In this regard, this study aims to analyse empirically a relationship between the types of long-term care services that demented patients wanted to take and they actually received during 2004. The caregivers of 609 dementia patients, who were randomly selected in a manner of proportional allocation from a nationwide claim database of the Korean National Health Insurance Corporation, were interviewed in September, 2005. Independent variables include socio-demographic characteristics, Activities of Daily Living(ADL) and Instrumental Activities of Daily Living(IADL). To explore the correspondence of the types of long-term care services that demented patients wanted to take and that they actually received, and its affecting factors, we conducted chi-square test and logistic regression analysis. Main findings are as follows. First, while only 20% of study subjects wanted home services as a long-term care services, those who wanted to use the long-term care facilities and general hospital were 37%, 43% respectively. Second, the correspondence rate was just 38% on average, and extremely low in the demented patients who wanted to use long-term care facilities. Third, the demented patients who resided in urban areas and received relatively high level of education showed high correspondence rate. Fourth, the high ADL score was closely related to low correspondence rate.

• Journal of Sensor Science and Technology
• /
• v.24 no.4
• /
• pp.239-246
• /
• 2015

Blood pressure is possible to diagnose a disease associated with blood pressure and judgment the current health of patients. Automatic blood pressure monitor capable of measuring a blood pressure easily in hospital and at home have become spread. In this study, we developed the blood pressure simulator (BPS) that can test the arm-type automatic blood pressure monitor that is commonly used in hospital. BPS is to produce a pressure similar to the pressure wave generated in the human blood using a servo disk motor. Then, using the silicon tube, it implements the situations such as human blood vessels, and to output the generated pressure waveform. Simply the BPS's phantom put on the cuff and it is able to simulate blood pressure. So anyone can quickly test the blood pressure monitor within one minute and it is possible to shorten the test time required for the automatic blood pressure monitor. In Performance test, the trends and the standard deviation of the values measured in the BPS is similar to the value of the measured pressure from people with normal blood pressure. Thus, the development BPS showed a possibility of taking into account the actual blood pressure measurement environment simulator.