• Journal of Soil and Groundwater Environment
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• v.21 no.3
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• pp.35-48
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• 2016

A micromodel was applied to estimate the effects of geological conditions and injection methods on displacement of resident porewater by injecting scCO₂ in the pore scale. Binary images from image analysis were used to distinguish scCO₂-filled-pores from other pore structure. CO₂ flooding followed by porewater displacement, fingering migration, preferential flow and bypassing were observed during scCO₂ injection experiments. Effects of pressure, temperature, salinity, flow rate, and injection methods on storage efficiency in micromodels were represented and examined in terms of areal displacement efficiency. The measurements revealed that the areal displacement efficiency at equilibrium decreases as the salinity increases, whereas it increases as the pressure and temperature increases. It may result from that the overburden pressure and porewater salinity can affect the CO₂ solubility in water and the hydrophilicity of silica surfaces, while the neighboring temperature has a significant effect on viscosity of scCO₂. Increased flow rate could create more preferential flow paths and decrease the areal displacement efficiency. Compared to the continuous injection of scCO₂, the pulse-type injection reduced the probability for occurrence of fingering, subsequently preferential flow paths, and recorded higher areal displacement efficiency. More detailed explanation may need further studies based on closer experimental observations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4561-4568
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• 2011

In this paper, carrier comparison PWM method for voltage control of Vienna rectifier is discussed. In general, in industrial and communications applications, the two-level rectifier is used. However, this two-level rectifier has the limit of high THD and low efficiency. So, the studies of three-level rectifier has been carried out so far, and the Vienna rectifier circuit is the representative. The space vector pulse width modulation(SVPWM) method is generally used for Vienna rectifier, in which voltage vectors and duration time are calculated from the voltage reference. However, this method require very sophisticated and complex calculations, so realizing this method by software is very difficult. To overcome this disadvantage, simple carrier comparison PWM method for Vienna rectifier is proposed which is modified from the carrier comparison method for 3 level inverter. Furthermore, to verify the usefulness of the Vienna rectifier carrier comparison PWM the simulation and experiment are carried out.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.3
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• pp.183-190
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• 2020

Although membrane bio-reactor (MBR) has been widely applied for wastewater treatment plants, the membrane fouling problems are still considered as an obstacle to overcome. Thus, many studies and commercial developments on mitigating membrane fouling in MBR have been carried out. Recently, high voltage impulse (HVI) has gained attention for a possible alternative technique for desalting, non-thermal sterilization, bromate-free disinfection and mitigation of membrane fouling. In this study, it was verified if the HVI could be used for mitigation of membrane fouling, particularly the internal pore fouling in MBR. The HVI was applied to the fouled membrane under different conditions of electric fields (E) and contact time (t) of HVI in order to investigate how much of internal pore fouling was reduced. The internal pore fouling resistance (R_f) after HVI induction was reduced as both E and t increased. For example, R_f decreased by 19% when the applied E was 5 kV/cm and t was 80 min. However, the R_f decreased by 71% as the E increased to 15 kV/cm under the same contact time. The correlation between E and t that needed for 20% of R_f reduction was modeled based on kinetics. The model equation, E^1.54t = 1.2 × 10³ was obtained by the membrane filtration data that were obtained with and without HVI induction. The equation states the products of En and t is always constant, which means that the required contact time can be reduced in accordance with the increase of E.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.6
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• pp.490-495
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• 2016

Pulsed eddy current (PEC) testing signals have typically been obtained from the electromotive force induced in a sensor coil. However, an increasing number of studies have elected to incorporate the Hall plate as a sensor. Thus, accurate numerical modeling of the Hall sensor signal is necessary. In this study, a PEC probe is designed and a numerical modeling program is written so that Hall sensor signals and coil sensor signals can be calculated simultaneously. First, a step current is used as the input current. The predicted Hall sensor signals show similar characteristics to those of the experimental signals reported by other researchers. The characteristics of the two types of signals are then analyzed and compared as the thickness of test object changes. The results show that the Hall sensor signal provides less information for evaluating the thickness of the test object than the coil sensor signal. The response signals from a pulsed input current are also calculated, and it is confirmed that an equivalent reversed signal pattern appeared after the pulse width at both signals.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4662-4679
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• 2015

Currently, the leakage of internal information has emerged as one of the most significant security concerns in enterprise computing environments. Especially, damage due to internal information leakage by insiders is more serious than that by outsiders because insiders have considerable knowledge of the system's identification and password (ID&P/W), the security system, and the main location of sensitive data. Therefore, many security companies are developing internal data leakage prevention techniques such as data leakage protection (DLP), digital right management (DRM), and system access control, etc. However, these techniques cannot effectively block the leakage of internal information by insiders who have a legitimate access authorization. The security system does not easily detect cases which a legitimate insider changes, deletes, and leaks data stored on the server. Therefore, we focused on the insider as the detection target to address this security weakness. In other words, we switched the detection target from objects (internal information) to subjects (insiders). We concentrated on biometrics signals change when an insider conducts abnormal behavior. When insiders attempt to leak internal information, they appear to display abnormal emotional conditions due to tension, agitation, and anxiety, etc. These conditions can be detected by the changes of biometrics signals such as pulse, temperature, and skin conductivity, etc. We carried out experiments in two ways in order to verify the effectiveness of the emotional recognition technology based on biometrics signals. We analyzed the possibility of internal information leakage detection using an emotional recognition technology based on biometrics signals through experiments.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.162-170
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• 2008

Kamisungihwalhyul-tang(KSHT) has been used for many years as a therapeutic agent for cerebrovascular disease and hypertension in Oriental Medicine. But the effect of KSHT on hypertension and reactive oxygen is not well-known. This study was examined to investigate the effect of KSHT on hypertension and reactive oxygen. After administering KSHT extract to Sprague- Dawley Rat forinjected subcutaneous with deoxycorticosterone acetate(DOCA) 8 weeks, changes in blood pressure, pulse rate, 2,2-diphenyl-1-picrylhydrazyl, reactive oxygen species, angiotensin converting enzyme, aldosterone, catecholamine levels, electrolyte, uric acid, BUN, creatinine in plasma were examined, and immunohistochemical changes and scanning electron microscopic changes were observed. 2,2-diphenyl-1-picrylhydrazyl(DPPH) scavenging activity was increased, reactive oxygen species(ROS) was decreased in a KSHT concentration-dependent. Angiotensin converting enzyme(ACE) inhibitory activity was increased in a concentration-dependent by KSHT. KSHT significantly decreased the blood pressure and heart rate in DOCA-salt hypertensive rat. KSHT significantly decreased the levels of aldosterone in DOCA-salt hypertensive rat. KSHT significantly decreased the level of dopamine, norepinephrine, epinephrine in DOCA-salt hypertensive rat. $Na^+$, $K^+$ and Cl- were decreased significantly, $Ca^{2+}$ was increased significantly by KSHT. KSHT significantly decreased uric acid, BUN, creatinine.

• The Journal of Korean Obstetrics and Gynecology
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• v.31 no.3
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• pp.33-49
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• 2018

Objectives: The purpose of this study was to investigate the correlation between Pattern identification instrument and biomarkers in polycystic ovary syndrome patients. Methods: Pattern identification instrument questionnaire, Sasang constitutional test, body composition test, pulse analyzing test, laboratory test were performed and the results were analyzed. Correlation analysis was performed between pattern identification and laboratory test results. Results: Testosterone, SHBG, $17{\alpha}$-OH-progesterone, AMH were highest in the Kidney-Yang Deficiency (腎陽虛) group. LH, FSH, LH/FSH ratio were the highest in the Endogenous Heat due to Yin Deficiency (陰虛內熱) group. DHEA-S was the highest in the Dampness-Heat in Liver Meridian (肝經濕熱) group. E2, Prolactin, Cholesterol, Triglyceride, HDL-Cholesterol, LDL-Cholesterol, Glucose (FBS), Insulin, HOMA-IR ratio, HbA1c were the highest in the Phlegm-Dampness (痰濕) group. Conclusions: In this study, we obtained basic data analyzing the correlation between pattern identification instrument and biomarkers in polycystic ovary syndrome patients. If further studies are performed, we expect to be able to obtain clues to study the mechanism of polycystic ovary syndrome.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.11-15
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• 1999

In order to evlauate feasibility of the gene tagging by the maize transposable element Ac in heterologous plant systems, we have investigated physical distances and directions of transposition of the element in Arabidopsis thaliana and tobacco cultured cell line BY-2. We prepared a T-DNA construct that carried a non-autonomous derivative of Ac with a site for cleavage by endonuclease I-Scel (designated dAc-I-RS element). Another cleavage site was also introduced into the T-DNA region outside dAc-I-RS. A number of transgenic Arabidopsis plants were generated, each of which had a single copy of the T-DNA at a different chromosomal location. To examine the pattern of transposition, three out of these transgenic plants were crossed with the Arabidopsis plant that carried the gene for Ac transposase and progeny in which dAc-I-RS had been transposed were isolated. After digestion of the genomic DNA of these progeny with I-SceI, sizes of segment of DNA were determined byd pulse-field gel electrophoresis. We also performed linkage analysis for the transposed elements and sites of mutations near the elements. Our results with three transgenic lines showed that 50% of all transposition events had occurred within 1,700 kilo-base pairs (kb) on the same chromosome, with 35% within 200 kb, and that the elements transposed in both directions on the chromosome with roughly equal probability. The data thus indicate that the Ac-Ds system is most useful for tagging of genes that are present within 200 kb of the chromosomal site of Ac in Arabidopsis. In addition, determination of the precise localization of the transposed dAc-I-RS element should definitely assist in map-based cloning of genes around insertion sites. In the present paper, we report typical examples of such gene isolation studies.

• Proceedings of the Botanical Society of Korea Conference
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• 1985.08b
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• pp.51-57
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• 1985

In order to evlauate feasibility of the gene tagging by the maize transposable element Ac in heterologous plant systems, we have investigated physical distances and directions of transposition of the element in Arabidopsis thaliana and tobacco cultured cell line BY-2. We prepared a T-DNA construct that carried a non-autonomous derivative of Ac with a site for cleavage by endonuclease I-Scel (designated dAc-I-RS element). Another cleavage site was also introduced into the T-DNA region outside dAc-I-RS. A number of transgenic Arabidopsis plants were generated, each of which had a single copy of the T-DNA at a different chromosomal location. To examine the pattern of transposition, three out of these transgenic plants were crossed with the Arabidopsis plant that carried the gene for Ac transposase and progeny in which dAc-I-RS had been transposed were isolated. After digestion of the genomic DNA of these progeny with I-SceI, sizes of segment of DNA were determined byd pulse-field gel electrophoresis. We also performed linkage analysis for the transposed elements and sites of mutations near the elements. Our results with three transgenic lines showed that 50% of all transposition events had occurred within 1, 700 kilo-base pairs (kb) on the same chromosome, with 35% within 200 kb, and that the elements transposed in both directions on the chromosome with roughly equal probability. The data thus indicate that the Ac-Ds system is most useful for tagging of genes that are present within 200 kb of the chromosomal site of Ac in Arabidopsis. In addition, determination of the precise localization of the transposed dAc-I-RS element should definitely assist in map-based cloning of genes around insertion sites. In the present paper, we report typical examples of such gene isolation studies.

• Korean Journal of Acupuncture
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• v.30 no.1
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• pp.47-55
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• 2013

Objectives : The purpose of this study was to determine whether electroacupuncture(EA) is effective in reducing pain on the severe ankle sprain classified as grade 3 in rats. Methods : The severe(grade 3) ankle sprain model was induced surgically by ankle ligament injury(the anterior talofibular, the calcaneofibular and the posterior talofibular) in the Sprague-Dawley rats(180~250 g). The effects of EA on weight bearing forces(WBR) of the affected foot were examined in a rat model of ankle sprain. EA was applied to either SI6, ST37, GB34, GB39 or GB42 acupoints by trains of electrical pulses(2 Hz, 1 ms pulse width, 2 mA intensity) for 15 min. Results : Cutting of the lateral ankle ligament complex produced the severe ankle sprain symptoms as grade 3. EA of the contralateral SI6 resulted in more analgesic effect than one of ipsilateral SI6 even though there was significant effect. EA of the ipsilateral GB34 and GB39 produced potent analgesic effects on the surgical ankle sprained pain behaviors. However, there were no significant analgesic effects in the contralateral GB34 and GB39 EA groups. In addition, both side of ST37 and GB42 did not result in analgesic effect on the surgical ankle sprained rat. Conclusions : The data suggest that EA induced analgesia shows point specificity on the severe ankle sprained pain model classified as grade 3.