• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.25-31
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• 2023

In order to estimate the radial speed of an underwater object so-called target with active sonar, Continuous Wave (CW) pulse is generally used, but if a target is slow and at near distance, it is not easy to estimate the radial velocity of the target due to acoustic reverberation in the ocean. In 2017, Wang et al. utilized broadband signal of two Hyperbolic Frequency Modulation (HFM) pulses, which is known as a doppler-invariant pulse, with equal frequency band and in opposite sweep directions to overcome this problem and successfully estimate the radial speed of slow-moving nearby target. They demonstrated the estimation of the radial velocity with computer simulation using the parameters of two HFM starting time differences and receiving times. However, for it uses two HFM pulses with equal frequency, cross-correlation between the two pulses negatively affect the detection performance. To mitigate this cross-correlation effect, we suggest using two different band HFM with the opposite sweep directions. In this paper, a method of radial velocity estimation is derived and simulated using two HFM pulses with the pulse length of 1 second and bandwidth of 400 Hz. Applying the suggested method, the radial velocity was estimated with approximately 6 % of relative error in the simulation.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.217-225
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• 2023

2,3-Butanediol (2,3-BDO), which is used in various fields such as cosmetics and fertilizers, is a high value-added substance and the demand for it is gradually increasing. 2,3-BDO produced from the fermentation of microorganisms not only contains by-products of fermentation, but also varies greatly in feed composition depending on fermentation conditions, so it is difficult to efficiently operate the separation process to reach the target purity of the product. Therefore, in this study, through dynamic optimization of the bio-based 2,3-BDO distillation process, the optimal control route was explored to control the 2,3-BDO concentration of the bottom product to 99 wt% or more, when feed concentration changes. Steady and dynamic state process simulation, proportional integral (PI) controller design, and dynamic optimization were sequentially performed. As a result, the error between the 2,3-BDO concentration and the set point of the bottom product was reduced by 75.2%.

• Journal of the Korean Geotechnical Society
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• v.24 no.9
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• pp.13-21
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• 2008

Partitioning tracer method is a useful tool to characterize large domains of the aquifers contaminated with light nonaqueous phase liquids (LNAPLs). Sorption of the partitioning tracers to the organic matter content of soil can potentially influence the efficacy of partitioning tracer method. LNAPL-water partitioning coefficients of tracers ($K_{nw}$), measured by static method, showed linear relationship. Sorption isotherm tests were conducted to evaluate the sorption capacity of the soils packed in the columns and the results were appropriately represented by Freundlich sorption isotherm. The sorption of tracers proportionally increased with the increase of the organic matter content of the soil. Laboratory experiments were conducted in four columns each packed with soils of different organic matter contents to determine the potential interference effects of sorption to soil organic matter content and correction factors for the errors in estimation of LNAPLs by partitioning tracer method. Though there were no contaminants added, breakthrough curves from columns packed with mixture of Jumunjin standard sand and organic matter showed separation of tracers. Columns were then contaminated to residual saturation with kerosene and breakthrough curves were obtained. The results show that sorption of tracers to soil organic matter leads to an increase in the retardation factor (R) and hence, to an overestimation of the saturation of LNAPLs. A relation between the percentage of organic matter content and the corresponding percentage error in the estimation of NAPLs has been developed.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.17-21
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• 2022

A new rapid and simple method for metalaxyl in Atractylodes macrocephala Koidzumi and Achyranthes japonica Nakai has been developed and validated. This study was conducted to develop a method for analyzing metalaxyl by a method based on QuEChERS using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Samples were extracted with acetonitrile and purified using amino-propyl (NH₂) Solid Phase Extraction cartridge. The method limit of quantitation (MLOQ) was 0.01 mg/kg. The linearity of matrix-matched calibration curve (r²) was ≥0.99 at the calibration range of 0.001-0.05 mg/kg. For recovery test, Atractylodes macrocephala Koidzumi or Achyranthes japonica Nakai was treated with standard solutions at MLOQ and 10MLOQ levels. Recovery rates were in the range of 88.1-109.1% with <5.5% coefficient of variation. This established analytical method was fully validated. Based on these results, it can contribute to improving the safety of residual pesticides in Atractylodes macrocephala Koidzumi and Achyranthes japonica Nakai.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1A
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• pp.1-8
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• 2009

Stay cable is easily exposed to vibration induced rainy wind effects. There are some problems for not only unexpected vibration but also well-known vibration. An outbreak of displacement by the said effects brings damages such as over-tension of cables and barriers, fatigue of anchorages and dampers, and additional shear force variation of stiffening girders. This study suggests analytic methodology for dynamic tension variation of cables and shear force variation of stiffening girders. Additionally this study announces with dynamic problems for cable stayed bridge briefly. To realize this subject, we divide restoring force into chord component and normal component and then make up the differential equations which can satisfy physical phenomenon for each component. Finally we apply adequate functions such as sinusoidal and parabola in order to reduce these differential equations. Therefore we can meet with good results through a series of above process. As a remarkable result, CIP recommendations (2002) give inadequate solution with over 10% error. However it gives very good solution if parts of our study are reflected at the said recommendations. The fact means that CIP recommendations (2002) well-known as international standard of stay cables are not even concern about this subject yet. For verification of this study, F.E. analysis using E.C.C. with external forces was fulfilled, and the accuracy and conciseness of this study were shown.

• The KIPS Transactions:PartB
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• v.19B no.2
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• pp.123-126
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• 2012

This paper proposed a method to separate a liver into left and right liver lobes for simple and exact volumetry of the river graft at abdominal MDCT(Multi-Detector Computed Tomography) image before the living donor liver transplantation. A medical team can evaluate an accurate river graft with minimized interaction between the team and a system using this algorithm for ensuring donor's and recipient's safe. On the image of segmented liver, 2 points(PMHV: a point in Middle Hepatic Vein and PPV: a point at the beginning of right branch of Portal Vein) are selected to separate a liver into left and right liver lobes. Middle hepatic vein is automatically segmented using PMHV, and the cutting line is decided on the basis of segmented Middle Hepatic Vein. A liver is separated on connecting the cutting line and PPV. The volume and ratio of the river graft are estimated. The volume estimated using 2 points are compared with a manual volume that diagnostic radiologist processed and estimated and the weight measured during surgery to support proof of exact volume. The mean ${\pm}$ standard deviation of the differences between the actual weights and the estimated volumes was $162.38cm^3{\pm}124.39$ in the case of manual segmentation and $107.69cm^3{\pm}97.24$ in the case of 2 points method. The correlation coefficient between the actual weight and the manually estimated volume is 0.79, and the correlation coefficient between the actual weight and the volume estimated using 2 points is 0.87. After selection the 2 points, the time involved in separation a liver into left and right river lobe and volumetry of them is measured for confirmation that the algorithm can be used on real time during surgery. The mean ${\pm}$ standard deviation of the process time is $57.28sec{\pm}32.81$ per 1 data set ($149.17pages{\pm}55.92$).

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.202-208
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• 2012

A high-performance liquid chromatographic (HPLC) method was developed to determine residues of cyromazine, a triazine insecticide, in agricultural commodities. Cyromazine was extracted with 90% aqueous methanol from representative crops which comprised brown rice, oyster mushroom, oriental melon, watermelon, and Chinese cabbage. Following to evaporation of methanol in the extract, the aqueous concentrate was acidified to form the protonated cyromazine. Dichloromethane partition was then applied to remove nonpolar co-extractives in the aqueous phase. Strong cation-exchange chromatography using Dowex 50W-X4 resin was employed for final purification of the extract. Cyromazine was successfully separated on a Zorbax SB-Aq $C_{18}$ column showing high retention for polar compounds. Cyromazine was sensitively quantitated by ultraviolet absorption at 214 nm. Limit of quantitation (LOQ) of the method was 0.04 mg/kg irrespective of sample types. Each crops were fortified at 3 different concentrations of cyromazine for recovery test. Mean recoveries from samples fortified at LOQ~2.0 mg/kg in triplicate ranged 80.2~103.3% in five agricultural commodities. Relative standard deviations in recoveries were all less than 6%. A selected-ion monitoring LC/MS method with electrospray ionization in positive-ion mode was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to routinely determine and inspect the residue of cyromazine in agricultural commodities.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.2
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• pp.92-96
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• 2018

Purpose In case of nuclear medical hepatobiliary scan, To quantitatively evaluate contractility of a gallbladder, gallbladder ejection fraction (GBEF%) is calculated from anterior images using fatty meal. However, when a gallbladder and other organs overlap on an anterior image, the gallbladder ejection fraction is not accurately evaluated. In order to reduce this error, the objective of our study was to figure out whether there is a significant difference in GBEF% calculated from the anterior and right lateral images. Materials and Methods After intravenous injection of 99mTc-Mebrofenin 370 MBq to randomly 50 patients who visited our hospital, we started to examine nuclear hepatobiliary scan. Using skylight(Philips, United States), we acquired anterior and right lateral image at 10 minutes, 20 minutes, 30 minutes, 60 minutes, 90minutes after injection. Using images at 60 and 90 minutes, gallbladder ejection fraction (GBEF%) was calculated from the anterior and right lateral images using JETstream workspace. For drawing more accurate ROI, CT images were referenced and 4 radiologists calculated the GBEF% in the same image and calculated the average value. We assessed whether there was a significant difference in GBEF% calculated from the anterior and right lateral images using SPSS program(Statistical Package for the Social Science, SPSS Ver.18 Inc. USA). Results About randomly 50 patients, the average value of the GBEF% calculated from the anterior image was 63.212 and the average value of the GBEF% calculated from the right lateral image was 62.666. GBEF% decreased 0.433% on the right lateral image compared with anterior image. Result of paired sample t-test, p value is over 0.05. So, there was no significant difference in GBEF% calculated from the anterior and right lateral images. Conclusion In the case that a gallbladder and other organs are not separated on an anteior image, Right lateral image would be better to acquire more accurate GBEF% than using anterior image.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.143-144
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• 2003

봄철 해역에 따른 부착미세조류의 영양성분 변화를 알아보기 위하여 본 실험을 수행하였다. 실험은 울진, 부안, 완도, 부산 지역에서 봄철인 2~4월 동안 실시되었으며 실험간의 오차를 줄이기 위해 실험 시작일의 차이는 최대 10일 이내로 하였다. 배양을 위한 실험해역의 기초 조사로 배양지역 연안해수의 수온, 염분, pH, 총질소, 총인, Chlorophyll-a의 측정을 하였고 각 지역의 부착미세조류를 수확하여 영양분석을 하였다. 실험에 사용된 파판은 전복 종묘생산에 이용되는 규조배양용 파판과 틀을 이용하였고 실험기간은 총 8주 동안 실시하였다. 2주마다 파판을 수거한 뒤 부착된 미세조류를 부드러운 솔로 분리하여 원심 분리한 후 지방산과 아미노산의 측정을 하였다. 또 각 시료의 일정량을 Sedwick-rafter counting chamber를 이용하여 검경ㆍ계수한 후 이를 단위면적당 개체수(cells/$\textrm{cm}^2$)로 환산하여 biomass를 구하였다. 봄철 지역간의 수온의 범위는 13.9~16.6$^{\circ}C$를 보였으며 울진이 가장 높고 부안지역이 가장 낮았다. 염분은 부안지역의 염분이 평균 2$\textperthousand$ 이상 낮았으며 그 외의 지역은 큰 차이가 없었다. pH는 7.77~8.21의 범위를 보이고 있었으며 질산염 농토는 부산이 0.265mg/$\ell$로 최대값을 보였고 울진이 0.032mg/$\ell$로 제일 낮았다. 인산염 농도는 완도지역이 0.018mg/$\ell$로 최대치를 보였고 부안은 검출되지 않았다. Chlorophyll-a의 농도는 울진지역이 0.66mg/$\ell$으로 제일 낮았으며 부산이 2.69mg/$\ell$, 부안지역이 2.27mg/$\ell$ 로 높은 값을 보였다. 봄철 지역에 따른 부착미세조류의 아미노산 분석결과는 울진이 실험지역 중 제일 높은 총 아미노산과 필수아미노산의 함량을 나타냈으며 각 지역별로 울진은 4주에 20.3%, 부안은 8주째 8.1%, 완도는 8주째 4.7%, 부산은 6주째 10.4%로 서로다른 시기에 높은 아미노산의 함량을 나타냈다. 실험지역 부착미세조류의 지방산 결과를 보면 전 실험기간동안 지방산 중 대부분은 $C_{18}$이하의 포화 또는 불포화 지방산이 주를 이루고 있었으며 palmitic acid( $C_{16:0}$)와 palmitoleic acid( $C_{16:0}$)의 양이 전체 지방산 함량중 37.47~75.94%로 대부분을 차지하고 있었다. 그리고 n-3HUFA(high unsaturated fat쇼 acids)인 EPA는 부안지역이 2주째 20.85%로 전체 지역중 함량이 제일 높았고, 울진은 실험기간중 6주가 14.76%로 제일 높은 함량을 보였다. 완도는 6주에만 10.97%의 함량을 보였으며 부산지역의 시료에서는 EPA의 검출이 없었다. 봄철 각지역에 설치된 파판에서의 부착미세조류 출현량을 보면 2주째의 부착미세조류량은 부안이 8.3$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 높았고 부산이 0.6$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 낮았다. 울진의 경우 0.7$\times$$10^3$ cells/$\textrm{cm}^2$로 부산과 비슷하게 낮은 출현량을 보였고 완도는 2.4$\times$$10^3$ cells/$\textrm{cm}^2$였다. 4주째의 출현량은 울진지역이 471.1$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 높았으며 부안, 완도, 부산 순으로 출현량이 낮았고 특히 부산은 1.2$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 낮았다. 6주째의 출현량은 울진 지역이 368.6$\times$$10^3$ cells/$\textrm{cm}^2$로 가장 높았으며 부안 89.8$\times$$10^3$ cells/$\textrm{cm}^2$, 완도 25.1$\times$$10^3$ cells/$\textrm{cm}^2$, 부산 5.9$\times$$10^3$ cells/$\textrm{cm}^2$ 순이었다. 8주째의 경우에도 울진, 부안, 완도, 부산이 각각 255.8$\times$$10^3$ cells/$\textrm{cm}^2$, 157.8$\times$$10^3$ cells/$\textrm{cm}^2$, 44.3$\times$$10^3$ cells/$\textrm{cm}^2$, 1.1$\times$$10^3$ cells/$\textrm{cm}^2$로 4주, 6주의 경우와 같은 경향을 보였다.보였다.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.2
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• pp.19-24
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• 2004

Introduction : The Vaginal, the urethra, the vulva and anal cancer avoid the many dose to femur head and the additional treatment is necessary in inguinal LN. The partial transmission block to use inguinal LN addition there is to a method which it treats and produce partial transmission block a method and the MLC which to it analyzes. Material & Methode : The Inguinal the LN treatment patient partial transmission it used block and the MLC in the object and with solid water phantom with the patient it reappeared the same depth. In order to analyze the error of the junction the EDR2 (Extended dose range, the Kodak and the U.S) it used the Film and it got film scanner it got the beam profile. The partial transmission block and the MLC bias characteristic, accuracy and stability of production for, it shared at hour and comparison it analyzed. Result : The partial the transmission block compares in the MLC and the block production is difficult and production hour also above 1 hours. The custom the block the place where it revises the error of the junction is a difficult problem. If use of the MLC the fabrication will be break and only the periodical calibration of the MLC it will do and it will be able to use easily. Conclusion : The Inguinal there is to LN treatment and partial transmission block and the MLC there is efficiency of each one but there is a place where the junction of block for partial transmission block the production hour is caught long and it fixes and a point where the control of the block is difficult. like this problem it transfers with the MLC and if it treats, it means the effective treatment will be possible.