• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.6-14
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• 2007

The purpose of urodynamic investigation is to determine information on the function of the urinary system. One of the most frequently used measurement procedures in urodynamics is filling and voiding cystometry using invasive method. But in this method transurethral catheter is use and it makes patients uncomfortable. The aim of this study was to implement the system that could evaluate the function of urinary tract with noninvasive and comfortable method. Therefor in this study, a sensor and measuring system were implemented to measure uroflow, urophonography and noninvasive bladder pressure signal during urination for diagnosing the LUTS(lower urinary tract symptoms) using noninvasive method. The implemented system compose of the sensor parts, signal conditioning parts, system control parts using FPGA and PC monitoring program. For the evaluation of the implemented system, the simulation of system's control part was performed and the model system for the lower urinary system was designed. From the evaluation of the model system, the mean error rate of the uroflow measurement part was 1.08% and coefficient of variation was 1,48. And the mean error rate of the noninvasive bladder pressure measurement part was 2.41% and coefficient of variation was 2.81. urophongraphy signal analysis was accomplished in a time domain and frequency domain. Average RMS power was used in a time domain analysis, and MF was used in a frequency domain analysis. From the evaluation of the model system average RMS power and MF was dependent on the occlusion degree significantly and median frequency range of $60{\sim}160Hz$ was correlated with the occlusion.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.554-566
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• 2018

The rice husk contains nutrients which can be easily utilized by microorganisms, and also has a water retaining ability, which played a crucial part in enabling it to become a biofilter media. In this study, we evaluated the applicability of rice husk pellet bio-scrubber as a microbiological carrier. The pelletization experiment of rice husk as a biological media was performed using PVA and EVA binder. Also, the feasibility tests of rice husk as a biological media for odor removal were carried out in order to know whether rice-husk contains useful components as a media for microbiological growth or not. Lastly, a combined test for odor gas absorption and biological oxidation was conducted using a lab scale bio-filter set-up packed with rice-husk pellets as wet-scrubber. The major components of the rice husk were carbon, hydrogen, nitrogen, and oxygen, while carbon acted as the main ingredient which comprised up to 23.00%. The C : N : P ratio was calculated as 45 : 1 : 2. Oxygen uptake rate, yield and decay rate of the rice husk eluent was calculated to be $0.0049mgO_2/L/sec$, 0.24 mgSS/mgCOD and 0.004 respectively. The most stable form of rice husk pellets was produced when the weight of the rice husk, EVAc, PVAc, and distilled water was 10 : 2 : 0.2 : 10. The prepared rice husk pellets had an apparent density of 368 g/L and a porosity of 59.00% upon filling. Dry rice husks showed high adsorption capacity for ammonia gas but low adsorption capacity for hydrogen sulfide. The bio-filter odor removal column filled with rice husk pellets showed more than 99.50% removal efficiency for NH3 and H2S gas. Through the analysis of circulation water, the prime removal mechanism is assumed to be the dissolution by water, microbial nitrification, and sulfation. Finally, it was confirmed that the microorganisms could survive well on the rice husk pellets, which provided them a stable supply of nutrients for their activity in this long-term experiment. This adequate supply of nutrients from the rice husk enabled high removal efficiency by the microorganisms.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.47-54
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• 2020

This study proposes an NFC-based payment system that considers user convenience while expanding the existing payment method for RFID-based individual food and logistics waste equipment. In line with this trend, I proposed to apply NFC to the existing RFID-based food meter to release the food in the meantime and to address the problem of re-carrying due to card loss, card not possessed, and non-filling, and the question that could not be identified by various cumbersome procedures. NFC's function alone has been certified for its convenience, which led to its introduction and research in the period of time. Of course, we need to negotiate fees with the transportation card company, but if we see a market share related to transportation card soon, we think smooth negotiations will take place. NFC method will be expanded to all phones with iPhone NFC opening. Therefore, in the next study, we intend to apply the payment system in NFC by linking with local currency, mobile vouchers, and card companies, which are being paid as respective payment means according to the recent emergency support system for COVID-19.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.311-320
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• 2018

The purpose of this study is to evaluate the flow ability of the thermoplasticized Gutta Percha in different temperatures. Four Gutta Percha products were classified by its hardness (soft, medium, and hard) and were experimented by the Rheometer (Melt flow indexer MFI-10, DAVENPORT, England) measuring apparatus, in $(23{\pm}2)^{\circ}C$, and in a relative humidity of ($50{\pm}5$) %, following the guidelines of ISO 1133-1:2011. The heating temperature ranged from $108^{\circ}C$, $160^{\circ}C$ to $200^{\circ}C$, and the load at 2.16 kg and 3.8 kg. The Gutta Percha was cut in 5 mm to be suitable for the rheometer pressurization process. After the experiment was conducted with a preheating time of 5 minutes, a cutting time of 5-240 seconds, and a sample of 10 grams, the Gutta Percha did not show any changes in fluidity for $108^{\circ}C$, $160^{\circ}C$, but showed a change in its flow ability in $200^{\circ}C$. Also, the Gutta Percha did not show any changes in its fluidity when it was pressurized by 2.16 and 3.8 kilograms. Therefore, this experiment shows that the heating temperature and the cut-off time showed a significance while measuring the melt flow rate.

• Journal of the Korea Convergence Society
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• v.12 no.7
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• pp.61-67
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• 2021

The purpose of this study was to investigate the colors of spectacle lenses that would be effective in blocking blue light among various colors so that the damage caused by blue light could be conveniently reduced even in daily life and when filling with dental light-curing resin. Each color dye of orange, brown, gray, yellow, red, and rosa was dissolved in an individual container of a spectacle lens tinting machine, and 6 uncolored spectacle lenses were immersed in a temperature of 90℃ for 1 hour to color. As a result of comparing the blue light transmittance of the colored spectacle lens and the tip for the photopolymerizer, the blue light transmittance of the orange colored lens was 0.82%, and the blue light blocking effssect was the best. Brown and gray tinted lenses had excellent blue light blocking rate, but it was difficult to recognize objects through the lens due to the high tinted concentration, and yellow tinted lenses were found to be effective when the tint was similar to the tip. The blue tinted lens had a blue light transmittance of 15.10%, which was lower than other tinted lenses. The results of the experimental study are expected to be helpful in recognizing the blue light transmittance by spectacle tinted lenses of various colors and making efforts to select the appropriate blue light blocking lens color and block harmful blue light stimuli.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.143-152
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• 2019

Purpose: The aim of this study is to investigate the characteristics of patients and teeth referred to a university dental hospital for endodontic problem. Materials and Methods: From January, 2017 to December, 2018, patients who were referred to a university dental hospital for endodontic problem were collected from clinical records. A total of 1171 patient records were analyzed. The status of the referred teeth was divided into three groups according to whether they were treated endodontically based on radiographs and clinical records at the time of referred visit. Results: 69.9% of the referred teeth were maxillary and mandibular first and second molars. The average time from referral to actual visit is 9.03 days and 65.6% of the case referred with referring letter. The most primary reasons of referral were persistent clinical symptom (pain, swelling, and sinus tract) (37.9%), diagnosis difficulty (16.7%), blockage of canal space (13.8%) and difficult tooth anatomy (11.4%). In the case of referral before endodontic treatment, the most primary reason of referral was failure to make a proper diagnosis. If the teeth were referred in the middle of endodontic treatment, the most primary reason of referral was persistent clinical symptom and blockage of canal space. In the case of referral after root canal filling, the most primary reason of referral was persistent clinical symptom. Conclusion: In the case of molars, the rate of persistent clinical symptom and blockage of canal space were the most primary reason of referral, and the rate of apical surgery and management of trauma was high in the case of anterior teeth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.193-203
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• 2019

The aim of this study was to analyze the relationship between rice yield and climate elements in Daegu (southern plain area) and Andong (inland mountainous area) regions. Over the past 20 years, rice yield has increased in both regions. The rice yield of middle and mid-late maturing cultivars in the recent 5 years increased by about 10% and 18%, respectively, compared to that produced in the early 2000s in the Daegu region. In the Andong region, the rice yield of mid-late maturing rice cultivars in the recent 5 years was higher by about 7% than that of the early 2000s. The number of panicles per hill and grain ripening rate significantly affected rice yield in mid-late maturing cultivars. In addition, the grain weight and grain ripening rate significantly affected rice production in middle maturing cultivars grown in the Daegu region. With regard to the middle maturing cultivars, the relationship between grain weight and rice yield had a positive significant correlation in both regions. To understand the effect of climate factors on rice yield, the milled rice yield of several rice cultivars produced over the past 20 years (1999-2018) at both locations, Daegu and Andong, were evaluated. The rice yields increased owing to long sunshine duration during the grain filling stage in the Daegu region. In Andong, rising maximum temperature during the vegetative stage increased rice yield of early and mid-late maturing cultivars. Long sunshine hours increased yield of mid-late maturing cultivars in both regions.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.275-284
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• 2022

Changes in air temperature, CO₂ concentration and precipitation due to climate change are expected to have a significant impact on soybean productivity. This study was conducted to evaluate the climate change impact on growth and development of determinate soybean cultivar in the southern parts of Korea. The high temperature during vegetative period, which does not accompany the increase of CO₂ concentration, increased the canopy photosynthetic rate in soybean, but after flowering, the high temperature above the optimal ranges interrupts the photosynthetic metabolism. In yield and yield components, high temperature reduced both the pod and seed number and single seed weight, resulting in a reduction of total seed yield. On the other hand, the increase in CO₂ concentration dramatically increased the canopy photosynthetic rate over the whole growth period. In addition, high CO₂ concentration increased the number of pods and seeds, which had a positive effect on total seed yield. Under concurrent elevation of air temperature and CO₂ concentration, canopy photosynthesis increased significantly, but enhanced canopy photosynthesis did not lead to an increase in soybean seed yield. The increase in biomass and branch by enhanced canopy photosynthesis seems to be attributed to an increase in the total number of pods and seeds per plant, which compensates for the negative effects of high temperature on pod development. However, Single seed weight tended to decrease rapidly by high temperature, regardless of CO₂ concentration level. Elevated CO₂ concentration did not compensate for the poor distribution of assimilations from source to sink caused by high temperature. These results show that the damage of future soybean yield and quality is closely related to high temperature stress during seed filling period.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.2
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• pp.97-100
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• 2018

Purpose The glomerular filtration rate (GFR) test is an important indicator of glomerular filtration and has been used to test renal function and the extent of its function. The GFR test is performed by intravenous injection of radioactive medicines made of $^{51}Cr$-EDTA, and blood concentration is measured by taking blood according to the elapsed time. also, PET-CT, bone scan, transfusion and so on will affect the outcome. Therefore, we will improve the quality of the test by providing guidelines for the GFR test for more accurate testing. Materials and Methods 5 mL of physiological saline solution and 2 mL of $^{51}Cr$-EDTA solution are used to make 5 mL of the radiopharmaceutical solution to be injected into the patient. First, the syringe weight is measured before the injection, and then the radioactive medicine is injected into the patient's vein and the syringe weight is measured after the injection. Blood sampling is performed twice in total. In adults, blood is collected 3 hours / 5 hours after injection and in children 2 hours / 5 hours after injection. The blood sample is centrifuged at 3300 rpm for 5 minutes. Standard solution is prepared by filling diluent water up to the scale indicated in the 200-mL volumetric flask, discarding $500{\mu}L$, injecting $500{\mu}L$ of GFR reagent and mixing well. $500{\mu}L$ each of the standard solution is dispensed into two test tubes, and $500{\mu}L$ of each of the plasma samples collected in time is dispensed into two test tubes and measured with a Cobra Counter. Results At present, the reference range applied in this study is $119.5{\pm}30.3ml/min/1.73m2$ for males and $125.2{\pm}28.2ml/min/1.73m^2$ for females. Conclusion The GFR test is conducted using radioactive medical products. GFR testing is performed as a scheduled test, but PET-CT, dialysis and transfusion, which may affect GFR testing, may be scheduled during GFR testing. Therefore, we could get accurate GFR test results by notifying the ward and department beforehand when booking.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.97-106
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• 2020

Swelling properties and shear strength behavior of MgO-Sand mixtures with hydration procese of MgO are compared according to different MgO contents (W_MgO/W_Total=0, 30, 50, 70, 100%) in this study. The specimens are prepared by mixing with crushed MgO refractory bricks and silica sand. After hydration, the particle size and the specific gravity of MgO were decreases. Through microstructure observation and X-ray diffraction analysis, it is confirmed that MgO changes from the cubic structure of Periclase to the hexagonal cubic structure of Brucite after hydration. As the MgO content increases, both swelling rate and swelling pressure of the mixtures increase. W_MgO/W_Total=30% specimen shows relatively low swelling pressure and swelling rate because produced Mg(OH)₂ mainly fills the pores between sand particles. However, in the case of MgO more than 50%, swelling pressure and swelling rate increase significantly because Mg(OH)₂ fills the pores of sand particles at first and then either pushes out sand particles or Mg(OH)₂ particles after filling the pores. As a result of the direct shear test, before hydration, the mixtures show a dilative behavior on high MgO contents and a contractive behavior on low MgO contents. However, after hydration, the behavior of all mixtures changes to contractive behavior. The threshold fraction of fine (i.e., Mg(OH)₂) contents of the hydrated MgO-Sand mixtures reveals approximately 60% compared with normalized shear strength.