• Physical Therapy Korea
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• v.13 no.3
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• pp.33-40
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• 2006

The purpose of this study was to assess the effects of High-Voltage Pulsed Current (HVPC) and ultrasound on adjuvant-induced arthritis in rats. Adjuvant arthritis was induced in female Sprauge-Dawley rats by the subcutaneous injection of a single dose of $.1m{\ell}$ of Complete Freund's Adjuvant (CFA) (1 mg of Mycobacterium Butyricum suspended in $.1m{\ell}$ paraffin oil) into the right hind paw. A randomized, parallel-groups design of 24 subjects was used. All rats were randomly assigned to control (n=8), ultrasound (n=8), and HVPC (n=8) were compared with those of injured rats. The rats in the pulsed ultrasound group were treated at 1 MHz frequency with $.5W/cm^2$ intensity in 1:4 mode for 5 minutes per day. The rats in the HVPC group were treated at 120 pulses per second and $50{\mu}s$ phase duration, 20 mA intensity for 30 min per day. Treatment was done in the left and right hind limb for 2 weeks. We evaluated clinical, radiographic, hematologic and histopathologic findings before and after treatment and obtained the following results. 1. Edema of the right hind paw was more significantly reduced in the ultrasound and HVPC groups than the control group on days 9, 12, and 14 (p<.05). Edema of the left hind paw was more significantly reduced in ultrasound and HVPC groups than the control group on days 12, 14 (p<.05). 2. WBC counts of the ultrasound and HVPC groups as compared with the control group were becoming remarkably decreased after the treatment. 3. In radiologic findings, arthritis formation was seen according to the score of arthritis, which was the highest in the control group, upon the observation of radiographs of the left and right hind paws. However, no statistically significant difference was present in the score within three groups. 4. In the histopathologic findings, ultrasound and HVPC groups had effectively suppressed erosions of articular cartilage and inflammatory cell infiltrations. Therefore, the results of the study show that rats that were treated with the ultrasound and HVPC effectively suppressed adjuvant arthritis. However, no statistically significant difference was present between the ultrasound group and the HVPC group.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.85-97
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• 2007

Statement of problem: Recently, anodic oxidation of cp-titanium is a popular method for treatment of titanium implant surfaces. It is a relatively easy process, and the thickness, structure, composition, and the microstructure of the oxide layer can be variably modified. Moreover the biological properties of the oxide layer can be controlled. Purpose: In this study, the roughness, microstructure, crystal structure of the variously treated groups (current, voltage, frequency, electrolyte, thermal treatment) were evaluated. And the specimens were soaked in simulated body fluid (SBF) to evaluate the effects of the surface characteristics and the oxide layers on the bioactivity of the specimens which were directly related to bone formation and integration. Materials and methods: Surface treatments consisted of either anodization or anodization followed thermal treatment. Specimens were divided into seven groups, depending on their anodizing treatment conditions: constant current mode (350V for group 2), constant voltage mode (155V for group 3), 60 Hz pulse series (230V for group 4, 300V for group 5), and 1000 Hz pulse series (400V for group 6, 460V for group 7). Non-treated native surfaces were used as controls (group 1). In addition, for the purpose of evaluating the effects of thermal treatment, each group was heat treated by elevating the temperature by $5^{\circ}C$ per minute until $600^{\circ}C$ for 1 hour, and then bench cured. Using scanning electron microscope (SEM), porous oxide layers were observed on treated surfaces. The crystal structures and phases of titania were identified by thin-film x-ray diffractmeter (TF-XRD). Atomic force microscope (AFM) was used for roughness measurement (Sa, Sq). To evaluate bioactivity of modified titanium surfaces, each group was soaked in SBF for 168 hours (1 week), and then changed surface characteristics were analyzed by SEM and TF-XRD. Results: On basis of our findings, we concluded the following results. 1. Most groups showed morphologically porous structures. Except group 2, all groups showed fine to coarse convex structures, and the groups with superior quantity of oxide products showed superior morphology. 2. As a result of combined anodization and thermal treatment, there were no effects on composition of crystalline structure. But, heat treatment influenced the quantity of formation of the oxide products (rutile / anatase). 3. Roughness decreased in the order of groups 7,5,2,3,6,4,1 and there was statistical difference between group 7 and the others (p<0.05), but group 7 did not show any bioactivity within a week. 4. In groups that implanted ions (Ca/P) on the oxide layer through current and voltage control, showed superior morphology, and oxide products, but did not express any bioactivity within a week. 5. In group 3, the oxide layer was uniformly organized with rutile, with almost no titanium peak. And there were abnormally more [101] orientations of rutile crystalline structure, and bonelike apatite formation could be seen around these crystalline structures. Conclusion: As a result of control of various factors in anodization (current, voltage, frequency, electrolytes, thermal treatment), the surface morphology, micro-porosity, the 2nd phase formation, crystalline structure, thickness of the oxide layer could be modified. And even more, the bioactivity of the specimens in vitro could be induced. Thus anodic oxidation can be considered as an excellent surface treatment method that will able to not only control the physical properties but enhance the biological characteristics of the oxide layer. Furthermore, it is recommended in near future animal research to prove these results.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.6
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• pp.51-64
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• 2022

Along with the urbanization, the risk of urban flooding due to climate change is increasing. Flood regulation, one of the ecosystem services, is implemented in the different level of function of flood risk mitigation by the type of ecosystem such as forests, arable land, wetlands etc. Land use changes due to development pressures have become an important factor in increasing the vulnerability by flash flood. This study has conducted evaluating the urban flood regulation service using InVEST UFRM(Urban Flood Risk Model). As a result of the simulation, the potential water retention by ecosystem type in the event of a flash flood according to RCP 4.5(10 year frequency) scenario was 1,569,611 tons in urbanized/dried areas, 907,706 tons in agricultural areas, 1,496,105 tons in forested areas, 831,705 tons in grasslands, 1,021,742 tons in wetlands, and 206,709 tons in bare areas, the water bodies was estimated to be 38,087 tons. In the case of more severe 100-year rainfall, 1,808,376 tons in urbanized/dried areas, 1,172,505 tons in agricultural areas, 2,076,019 tons in forests, 1,021,742 tons in grasslands, 47,603 tons in wetlands, 238,363 tons in bare lands, and 52,985 tons in water bodies. The potential economic damage from flood runoff(100 years frequency) is 122,512,524 thousand won in residential areas, 512,382,410 thousand won in commercial areas, 50,414,646 thousand won in industrial areas, 2,927,508 thousand won in Infrastructure(road), 8,907 thousand won in agriculture, Total of assuming a runoff of 50 mm(100 year frequency) was estimated at 688,245,997 thousand won. In a conclusion. these results provided an overview of ecosystem functions and services in terms of flood control, and indirectly demonstrated the possibility of using the model as a tool for policy decision-making. Nevertheless, in future research, related issues such as application of models according to various spatial scales, verification of difference in result values due to differences in spatial resolution, improvement of CN(Curved Number) suitable for the research site conditions based on actual data, and development of flood damage factors suitable for domestic condition for the calculation of economic loss.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.251-268
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• 1998

125 Cases of Acne were treated by Acupuncture and Herb-med treatment during a three months duration from April 1996 to February 1998 in Kyung Hee Univ. Department of Ophthal, Otolaryngology. College of Oriental Medicine. We have observed the cases and the results as follows: 1. The age of average was 24.55 age : 21.91 in males, 24.55 in females. and in these, the gulf between males and females were showed statically significant diference. In the age of onset, averag was 16.96 age and mode was 18 age and male's average was 16.96 age, minimun was 11 age, maximum 40 age and female's average was 20.14 age, minimun was 10 age, maximum 40 age. and these were showed statically significant diference between males and females. 2. In the distribution of season, winter was the most with $37.8\%$ of out patients, the rest was similar to difference of each other. but there was clear difference between males and females. 3. In the duration of history, the average was 5.10 years and male's average was 5.13 years. on the other hand female's was 5.09 years but there is no any significant difference have a resemblance with each other. 4. In blood type, O type was the most with $35.20\%$ and there was in the order of A type was $26.40\%\;B\;type\;was\;23.20\%,\;AB\;type\;was\;15.20\%$ but these were not significant difference by the chi-tend and analysis of variance with total cases, males and females. 5. In select of the preference food, patients of the prefer worm food was $42.40\%\;and\;cool\;food\;was\;38.40\%,\;tepid\;food\;was\;24\%$ but these were no significant difference by the chi-test and ANOVA of each other. 6. the state of pulse classified into 11 type and average was 7.2 times, maximum was 29 times with Hyun Sae, at the same time, the female's average was 6.73 times, maximum was 27 times and male's average was 1.5 times. The result of test with each other, these were showed statically significant difference as compared total cases with males but there were not females ones. 7. In the frequency of the major cause, oversensitiveness was the most with $34.93\%$. secondly there was in order of indigestion $30.82\%$ and menstrual irregularity and menstruation pain $23.28\%$. constipation $10.96\%$ and these showed statically significant difference as compared the females with males on the result of test for difference with each other. 8. In frequency of the symptoms, itching was the most with $31.97\%$ and there was in order of nodule $20.49\%$, pustule $18.85\%,\;papule\;15.58\%,\;flare\;13.12\%$ and also these showed statically significant difference as compared the females with males 9. for the Distribution of acne region, face was the most with $64.06\%$ and there was in order of back $14.29\%,\;upper-chest\;11.69\%,\;neck\;7.79\%$ and there was no significant difference as compared total cases with males and females. 10. Acne applied 30 prescription to 4 weeks and over and 20 weeks and over was $23.3\%$, 30 weeks and over was $16.67\%$ and average of administration duration were 4.2 weeks(male's average 5.78, maximum 96 weeks and female's average 3.85, maximum 23 weeks) maximum was 96 weeks, minimum was 1 week. 11. In the acupuncture treatment, $96.6\%$ applied to acupuncture and average was 5.44 times, maximum 46 times, minimum 1 time(male's average 4.64, female's 5.62) but these were not any significant differeence. 12. for the medication, author made a investigation and comparison between control group with treated group in order to observe for the therapeutic effect during the 1 month and 2, 3. From these results, we can see that acne was improved by the oriental treatment. in the 1 month, average of control group was 13.24 and treated group was 11.78. these showed statically significant decrease in P<0.02 as compared the treated group with control group. In the 2 months, average of control group was 13.43 and treated group was 9.03. these showed statically significant decrease in P<0.003 as compared the treated group with control group. In the 3 months, average of control group was 13.78 and treated group was 8.06. these showed statically significant decrease in P<0.008 as compared the treated group with control group.

• Journal of Convergence Society for SMB
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• v.6 no.4
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• pp.25-30
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• 2016

This paper presents on the development of a compact anti-lost device requested recently. The proposed device consists of the master and slave modules based on Bluetooth4.1 technology. To implement a low-power characteristic, an algorithm has been also developed. The transmitting and receiving circuits are designed by using BoT CLE110 module supporting Bluetooth 4.1. The ATmega 328P-AU was used for the control and LP3874EMP was used as a linear regulator. Power consumption of the fabricated product in operating mode is only 10mAh and 35mAh for MCU operating state. Alarm operation distance is $10m{\pm}30%$, the effective radiated power is less than 10mW, the frequency band is designed to operate in the Bluetooth band with 26MHz bandwidth. And algorithms have been developed to extend the battery life. The size of the product was obtained as $45{\times}45{\times}15mm$ for master and $35{\times}35{\times}10mm$ fr slave. After the optimization process, it is expected to be commercialized as a wristwatch for anti-lost device.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.11
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• pp.836-845
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• 2001

A Novel fully-differential bipolar current subtracter(FCS) and its application to current controlled current amplifier(CCCA) for high-accuracy current-mode signal processing were designed. To obtain full-differential current output, the FCS was symmetrically composed of two current follower with low current-input impedance. The CCCA to control output current by the bias current was consisted of the subtracter and a current gain amplifier(CGA) with single-ended current output.. The simulation result shows that the FCS has current-input impedance of 5 Ω and a good linearity. The CCCA has 3-dB cutoff frequency of 20 MHz for the range over bias current 100 $\mu$A to 20 mA. The power dissipation of the FCS and CCCA are 1.8 mW and 3 mW, respectively.

• Journal of Biosystems Engineering
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• v.18 no.3
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• pp.239-251
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• 1993

Data acquisition system and computer program developed in this study could be well used in engine vibration analysis. The system and program developed were also operated to be able to control measuring interval, number of channels, number of data. The flywheel was specially studied to provide the proper weight with rubber damper for the engine design at low level of vibration. This study was conducted to obtain basic data which affect the engine vibration. The experiment of this study was performed on original weight flywheel, weight-reduced flywheel, weight-reduced and rubber-coated flywheel, weight-reduced and damper-attached flywheel. Avarage of peak value, maximum vibration, power spectrum density based on FFT analysis are major factors of this experiment. Results were obtained as follows : 1. When rubber was inserted in the flywheel rim of which weight was reduced from 32.2kgf to 24.4 kgf, maximum vibration of the engine was decreased 48.3% at X axis, 35.5% at Y axis and 34.6% at Z axis in comparison with the flywheel of original weight. 2. When the flywheel of rubber damper was compared with the original flywheel, the average of absolute vibration for rubber damped flywheel was decreased at X, Y, Z axis and especially its decreasing rate was so high at X-axis comparing with the other flywheel, which implied that rubber damper was very useful to reducing the vibration of the engine at X axis. 3. Hysteresis losses of X, Y, Z axis were greatly decreased in the flywheel with rubber damper on rim. 4. Damped oscillation effect on X and Y axis vibration above average peak vibration by the flywheel of rubber damper on rim was larger than those by the other flywheels. 5. Power spectrums of vibration at real and imaginery part were bi-mode type. The vibration frequency of rubber dampered flywheel which weight is decreased was slightly increased as compared with original flywheel.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.29-36
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• 2000

The principle and design of two-stage CMOS operational amplifier with rail-to-rail input and class-AB output stage is presented. The rail-to-rail input stage shows almost constant transconductance independent of the common mode input voltage range in global transistor operation region. This new technique does not make use of accurate current-voltage relationship of MOS transistors. Hence it was achieved by using simple linear relationship of currents. The simulated transconductance variation using SPICE is less the 4.3%. The proposed global two-stage opamp can operate both in strong inversion and in weak inversion. Class AB output stage proposed also has a full output voltage swing and a well-defined quiescent current that does not depend on power supply voltage. Since feedback class- AB control is used, it is expected that this output stage can be operating in extremely low voltage. The variation of DC-gain and unity-gain frequency is each 4.2% and 12%, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.100-105
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• 2010

A multi-band low noise amplifier (LNA) is designed in 90 nm RF CMOS process for 3GPP LTE (3rd Generation Partner Project Long Term Evolution) applications. The designed multi-band LNA covers the eight frequency bands between 1.85 and 2.8 GHz. A tunable input matching circuit is realized by adopting a switched capacitor array at the LNA input stage for providing optimum performances across the wide operating band. Current steering technique is adopted for the gain control in three steps. The performances of the LNA are verified through post-layout simulations (PLS). The LNA consumes 17 mA at 1.2 V supply voltage. It shows a power gain of 26 at the normal gain mode, and provides much lower gains of 0 and -6.7 in the bypass-I and -II modes, respectively. It achieves a noise figure of 1.78 dB and a IIP3 of -12.8 dBm over the entire band.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.4
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• pp.315-322
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• 1998

Power conversion system must increase switching frequency in order to achieve small size, light weight and low noise. However, the switches of converter are subject to high switching power losses and switching stresses. As a result, the power system has a lower efficiency. In this paper, the authors propose an AC-DC boost converter of high efficiency by partial resonant switching mode. The switching devices in the proposed circuit are operated with soft switching and the control technique of those is simplified for switch to drive in constant duty cycle. The partial resonant circuit makes use of a inductor using step up and a condenser of loss-less snubber. Besides, by regenerating energy, that is charged in a loss less snubber condenser of a snubber adopted to a common circuit, toward an input source part, this circuit can get increased efficiency. as merit. The result is that the switching loss is very low, the efficiency and power factor of system is high. The proposed converter is deemed the most suitable for high power applications where the power switching devices are used.