• Title/Summary/Keyword: The weighting factor

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Optimization of PRISM parameters using the SCEM-UA algorithm for gridded daily time series precipitation (시계열 강수량 공간화를 위한 SCEM-UA 기반의 PRISM 매개변수 최적화)

  • Kim, Yong-Tak;Park, Moonhyung;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.53 no.10
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    • pp.903-915
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    • 2020
  • Long-term high-resolution hydro-meteorological data has been recognized as an essential element in establishing the water resources plan. The increasing demand for spatial precipitation in various areas such as climate, hydrology, geography, ecology, and environment is apparent. However, potential limitations of the existing area-weighted and numerical interpolation methods for interpolating precipitation in high altitude areas remains less explored. The proposed PRISM (Precipitation-Elevation Regressions on Independent Slopes Model) model can produce gridded precipitation that can adequately consider topographic characteristics (e.g., slope and altitude), which are not substantially included in the existing interpolation techniques. In this study, the PRISM model was optimized with SCEM-UA (Shuffled Complex Evolution Metropolis-University of Arizona) to produce daily gridded precipitation. As a result, the minimum impact radius was calculated 9.10 km and the maximum 34.99 km. The altitude of coastal weighted was 681.03 m, the minimum and maximum distances from coastal were 9.85 km and 38.05 km. The distance weighting factor was calculated to be about 0.87, confirming that the PRISM result was very sensitive to distance. The results showed that the proposed PRISM model could reproduce the observed statistical properties reasonably well.

Effect of Polygonatum Odoratum on Lowering Lipid and Antioxidation (옥죽(玉竹)의 지질강하 및 항산화효과)

  • Seo, Yong-Seok;Park, Won-Hyung;Cha, Yun-Yeop
    • Journal of Korean Medicine Rehabilitation
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    • v.21 no.2
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    • pp.49-62
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    • 2011
  • Objectives : This study was designed to examine the effects of Polygonatum odoratum EtOH ext. on lowering lipid and anti-oxidation using hyperlipidemic rat. Methods : Male rats weighting $195.21{\pm}4.93g$ were divided into 4 groups and fed high fat diet for 8 weeks. Each of 7 rats was divided into a control and sample group. We fed a control group of rats a basal diet and administered normal saline(100 mg/kg, 1 time/1 day) for 4 weeks. And we fed each experimental group of rats basal diet and administered an extract of Polygonatum odoratum(100 mg/kg, 200 mg/kg, 300 mg/kg, 1 time/1 day) for 4 weeks. At the end of the experiment, the rats were sacrificed to determine their chemical composition. We measured lipid of plasma and liver, concentration of anti-oxidative activity and tumor necrosis factor-$\alpha$($TNF-{\alpha}$). Results : 1. Concentration of plasma free fatty acid, low density lipoprotein-cholesterol showed a significant decrement in the 200 mg/kg and 300 mg/kg Polygonatum odoratum EtOH ext. groups than that of control group. Concentration of plasma total cholesterol, triglyceride showed a significant decrement in all Polygonatum odoratum EtOH ext. groups than that of control group. However, concentration of plasma high density lipoprotein-cholesterol was not significantly different in all the treatment groups. 2. Concentration of liver total cholesterol showed a significant decrement in the 200 mg/kg and 300 mg/kg Polygonatum odoratum EtOH ext. groups than that of control group. Concentration of liver triglyceride(TG) showed a significant decrement in all Polygonatum odoratum EtOH ext. groups than that of control group. 3. Concentration of plasma thiobarbituric acid reactive substance, and liver thiobarbituric acid reactive substance showed a significant decrement in the 200 mg/kg and 300 mg/kg Polygonatum odoratum EtOH ext. groups than that of control group. 4. The values of glutathione peroxidase activity showed a significant increment in all Polygonatum odoratum EtOH ext. groups than that of control group. The values of superoxide dismutase activity and catalase activity showed a significant increment in the 200 mg/kg and 300 mg/kg Polygonatum odoratum EtOH ext. groups than that of control group. 5. The values of plasma aspartate aminotransferase and alanine aminotransferase activities were not significantly different in all treatment groups. 6. Concentration of liver $TNF-{\alpha}$ showed a significant decrement in the 200 mg/kg and 300 mg/kg Polygonatum odoratum EtOH ext. groups than that of control group. Conclusions : Based on the results in this study, the Polygonatum odoratum EtOH ext. showed a positive effect in lowering lipid and anti-oxidation.

Pharmacokinetics of Anticancer Agent SB-31 in Rats & Rabbits and the Cardiovascular Effect on the Isolated Perfused Rat Heart & Blood Coagulation (SB-31의 Glycyrrhizin을 지표로 한 Rat과 Rabbit에서의 약물동태 및 심혈관계에 대한 효과 연구)

  • Kang, Won Ku;Park, Yong Soon;Lee, Dong Heum;Kwon, Kwang Il
    • Korean Journal of Clinical Pharmacy
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    • v.8 no.2
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    • pp.122-132
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    • 1998
  • SB-31 which contains Pursatilla, Licoris and Ginseng extracts was recently proved as an anticancer agent. In a preclinical effort to be applied this drug to human, pharmacokinetics of SB-31 was carried out in rats and rabbits. Glycyrrhizin(GZ), a saponin of Licoris was used as a standard ingradient for the pharmacokinetics of SB-31. The rat's blood, bile and urine samples were serially collected in femoral vein, common bile duct and bladder, respectively, after bolus i.v. injection at a dose of 1 or 1/5 ampul/rat and rabbit's blood samples from the marginal ear vein at a dose of 1 or 3 amp./rabbit. GZ and glycyrrhetic acid(GA), a major metabolite of GZ in the physiological samples were analysed by HPLC with UV detection. The decline of GZ in plasma concentration was generally biexponential at each dose. GZ was almost completely recovered in bile within 18 hour. GA wasn't detected in the samples with UV detector. In the rat, Vss and Kel at a dose of 1 and 1/5 ampul of SB-31 were $98.06\pm6.07\;ml,\;0.33\pm0.05\;hr^{-1}\;and\;65.46\pm11.19\;ml,\;0.68\pm0.25\;hr^{-1}$, respectively. Those in rabbits at a dose of 3 and 1 ampul of SB-31 were $235.24\pm30.72\;ml,\;0.13\pm0.36\;hr^{-1}\;and\;341.32\pm28.58\;ml,\;0.27\pm0.04\;hr^{-1}$, respectively. 'WinNonlin' was utilized for the compartmental analysis. A two-compartment model was chosen as the most appropriate pbarmaco-kinetic model. The data were best described by using a weighting factor of $1/y^2$. To evaluate the effect of SB-31 on cardiovascular system, serially diluted SB-31 was directly injected into coronary artery in the isolated perfused rat heart and the effect of PSF, PSH, saponins of Pursatilla, and SB-31 on PT, APTT of healthy human plasma was examined. Except the positive inotropic effect of ten times diluted solution of SB-31, there was no significant effect on LVDP, (- dp/dt)/(+dp/dt), heart rate and coronary flow in comparision with that of vehicle. SB-31 had no effect on PT but slightly delayed APTT about $6.9{\sim}11.5\%$. There was no significant effect of PSF and PSH on PT & APTT. Conclusively, SB-31 did not show any notable toxic effects on cardiovascular system.

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A Study on the Incidence of Side Effects according to the Number of Beams in Intensity-modulated Radiation Therapy for Prostate Cancer using 15 MV (15 MV를 이용한 전립샘암 세기조절 방사선치료 시 빔의 개수에 따른 부작용 발생률에 관한 연구)

  • Joo-Ah Lee
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.481-487
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    • 2023
  • In this study, we analyzed the incidence of side effects of photoneutron dose according to the number of beams during intensity-modulated radiotherapy of prostate cancer using 15 MV. The radiation treatment plan design for intensity-modulated radiation therapy for prostate cancer was established with a prescription dose of 220 cGy per dose and a total of 7260 cGy for 33 treatments. The linear accelerator used in the experiment is Varian's True Beam STx (Varian, USA). Photoneutron dose was generated by using 15 MV energy in the planning target volume (PTV). The treatment plan was designed with IMRT 5, 7, and 9 portals using the Eclipse System (Varian Ver 10.0, USA). An optically stimulated luminescence albedo neutron dosimeter (Landauer Inc., USA) was used to measure photoneutron dose. IMRT 5 portals, 1.7 per 1,000, 7 portals, 1.8 per 1,000, 9 portals, 2.0 per 1,000 were calculated as the probability of experiencing side effects on the thyroid gland due to photoneutron dose. This study studies the risk of secondary radiation exposure dose that can occur during intensity-modulated radiation therapy, and it is considered that it will be used as useful data in relation to stochastic effects in the future.

Single-Channel Seismic Data Processing via Singular Spectrum Analysis (특이 스펙트럼 분석 기반 단일 채널 탄성파 자료처리 연구)

  • Woodon Jeong;Chanhee Lee;Seung-Goo Kang
    • Geophysics and Geophysical Exploration
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    • v.27 no.2
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    • pp.91-107
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    • 2024
  • Single-channel seismic exploration has proven effective in delineating subsurface geological structures using small-scale survey systems. The seismic data acquired through zero- or near-offset methods directly capture subsurface features along the vertical axis, facilitating the construction of corresponding seismic sections. However, substantial noise in single-channel seismic data hampers precise interpretation because of the low signal-to-noise ratio. This study introduces a novel approach that integrate noise reduction and signal enhancement via matrix rank optimization to address this issue. Unlike conventional rank-reduction methods, which retain selected singular values to mitigate random noise, our method optimizes the entire singular value spectrum, thus effectively tackling both random and erratic noises commonly found in environments with low signal-to-noise ratio. Additionally, to enhance the horizontal continuity of seismic events and mitigate signal loss during noise reduction, we introduced an adaptive weighting factor computed from the eigenimage of the seismic section. To access the robustness of the proposed method, we conducted numerical experiments using single-channel Sparker seismic data from the Chukchi Plateau in the Arctic Ocean. The results demonstrated that the seismic sections had significantly improved signal-to-noise ratios and minimal signal loss. These advancements hold promise for enhancing single-channel and high-resolution seismic surveys and aiding in the identification of marine development and submarine geological hazards in domestic coastal areas.

Prediction of Column Axial Force in X-braced Seismic Steel Frames Considering Brace Buckling (가새좌굴을 고려한 X형 내진 가새골조의 기둥축력 산정법)

  • Yoon, Won Soon;Lee, Cheol Ho;Kim, Jeong Jae
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.523-535
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    • 2014
  • According to the capacity design concept underlying current steel seimsic provisions, the braces in concentrically braced frames should dissipate seismic energy through cyclic tension yielding and compression buckling. On the other hand, the beams and the columns in the braced bay should remain elastic for gravity load actions and additional column axial forces resulting from the brace buckling and yielding. However, due to the difficulty in accumulating the yielding and buckling-induced column forces from different stories, empirical and often conservative approaches have been used in design practice. Recently a totally different approach was proposed by Cho, Lee, and Kim (2011) for the prediction of column axial forces in inverted V-braced frames by explicitly considering brace buckling. The idea proposed in their study is extended to X-braced seismic frames which have structural member configurations and load transfer mechanism different from those of inverted V-braced frames. Especially, a more efficient rule is proposed in combining multi-mode effects on the column axial forces by using the modal-mass based weighting factor. The four methods proposed in this study are evaluated based on extensive inelastic dynamic analysis results.

Bioequivalency and Pharmacokinetics of Two Clarithromycin Tablets (Clarithromycin 정제의 생물학적 동등성 및 약물동태)

  • Kang, Won Ku;Park, Sun Young;Park, Yong Soon;Woo, Jong Su;Choi, Kyung Eob;Kwon, Kwang Il
    • Korean Journal of Clinical Pharmacy
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    • v.9 no.1
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    • pp.49-54
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    • 1999
  • This study was carried out to compare the bioavailability of Hanmi clarithromycin (250 mg/tablet) with that of $Klaricid^{(R)}$ The bioavailability was examined on 20 volunteers who received a single dose (500 mg) of each drug in the fasting state in a randomized balanced 2-way crossover design. After dosing, blood samples were collected for a period of 12 hours. Plasma samples were analyzed for clarithromycin and roxithromycin(internal standard) by HPLC/Coulometric BCD. The pharmaco-kinetic parameters ($AUC_{0-l2hr}$, Cmax, Tmax, $AUC_{inf}$, Ka, Kel, $t_{1/2}$, Vd/F and Cl/F) were calculated from the plasma clarithromycin concentration-time data of each volunteer. The computer program 'WinNonlin' was used for compartmental analysis. One compartment model with first-order input, from order output with lag time, weighting factor $l/y^2$ was chosen as the appropriate pharmacokinetic model. The major pharmacokinetic parameters ($AUC_{0-l2hr},\;AUC_{inf}$, Cmax and Tmax) of Hanmi clarithromycin were $10.7\pm0.5\;{\mu}g{\cdot}hr{\cdot}ml^{-1},\;12.7\pm0.7\;{\mu}g{\cdot}hr{\cdot}ml^{-1},\;1.7\pm0.1\;{\mu}g/ml\;and\;2.0\pm0.2\;hr$, respectively, and those of $Klaricid^{(R)}\;were\;9.8\pm0.5\;{\mu}g{\cdot}hr{\cdot}ml^{-1},\;11.7\pm0.6\;{\mu}g{\cdot}hr{\cdot}ml^{-1},\;1.6\pm0.1\;{\mu}g/ml\;and\;2.1\pm0.1\;hr$, respectively. The differences in mean values of $AUC_{0-l2hr},\;AUC_{inf}$ and Cmax between two products were $9.88\%,\;8.94%\;and\;6.59\%$, respectively. The least significant differences at $\alpha=0.05$ for $AUC_{0-l2hr},\;AUC_{inf}$ and Cmax were $16.08\%,\;17.81\%\;and\;18.94\%$, respectively. Though the plasma clarithromycin concentrations of Hanmi clarithromycin were higher than those of $Klaricid^{(R)}$ at all observed times, the bioavailability of Hanmi clarithromycin appeared to be bioequivalent with that of $Klaricid^{(R)}$. The Ka, Kel, $t_{1/2}$, Vd/F and Cl/F of the Hanmi clarithromycin were $2.69\pm0.53\;hr^{-1},\;0.18\pm0.01 hr^{-1},\;3.9\;hr,\;248.8\pm11.4\;L\;and\;43.7\pm2.6\;L/hr$, respectively, and those of $Klaricid^{(R)} were 2.19\pm0.51\;hr^{-1},\;0.18\pm0.02\;hr^{-1},\;3.7\;hr,\;266.7\pm22.4\;L\;and\;45.3\pm2.8L/hr$, respectively. There were no statistically significant differences between two drugs in all pharmacokinetic parameters.

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A Study on GA-based Optimized Polynomial Neural Networks and Its Application to Nonlinear Process (유전자 알고리즘 기반 최적 다항식 뉴럴네트워크 연구 및 비선형 공정으로의 응용)

  • Kim Wan-Su;Lee In-Tae;Oh Sung-Kwun;Kim Hyun-Ki
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.7
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    • pp.846-851
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    • 2005
  • In this paper, we propose Genetic Algorithms(GAs)-based Optimized Polynomial Neural Networks(PNN). The proposed algorithm is based on Group Method of Data Handling(GMDH) method and its structure is similar to feedforward Neural Networks. But the structure of PNN is not fixed like in conventional neural networks and can be generated in a dynamic manner. As each node of PNN structure, we use several types of high-order polynomial such as linear, quadratic and modified quadratic, and it is connected as various kinds of multi-variable inputs. The conventional PNN depends on the experience of a designer that select the number of input variables, input variable and polynomial type. Therefore it is very difficult to organize optimized network. The proposed algorithm leads to identify and select the number of input variables, input variable and polynomial type by using Genetic Algorithms(GAs). The aggregate performance index with weighting factor is proposed as well. The study is illustrated with tile NOx omission process data of gas turbine power plant for application to nonlinear process. In the sequel the proposed model shows not only superb predictability but also high accuracy in comparison to the existing intelligent models.

Water Allocation by Estimation of Damage Function in a Water-Deficit Situation (피해함수 산정을 통한 물 부족 상황에서의 용수배분 방안)

  • Yi, Choong-Sung;Park, Kyo;Choi, Seung-An;Shim, Myung-Pil
    • Journal of Korea Water Resources Association
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    • v.39 no.5 s.166
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    • pp.431-440
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    • 2006
  • Recently, water conflicts are rapidly increasing and more serious. So, it needs to establish the reasonable water allocation rules and criteria. This study aims at performing inter-sectoral water allocation with a focus on economic effciency and social utility. To allocate water among the sectoral water uses, water shortage damage functions were estimated and then converged to the utility functions. Finally, each sectoral water uses are allocated by applying 'law equimarginal utility' to maximize social utility. Also weighting factor which reflects scale and characteristic of water demand in a region was estimated to perform the inter-regional water allocation. The water allocation rule was applied to the future water-deficit situation in Han-river basin. As a result, domestic water use was allocated more sufficient agricultural and industrial water use. Also, the water shortage occurs severely in the rural area like Gangwon-do because of its low urbanization and industrialization. This study suggests a alternative view of the economic water allocation which have difficulty under water supply mechanism in Korea.

Developing system of forest habitat quality assessment for endangered species (멸종위기 야생생물 산림 서식지 질적 평가 체계 개발)

  • Kwang Bae Yoon;Sunryoung Kim;Seokwan Cheong;Jinhong Lee;Jae Hwa Tho;Seung Hyun Han
    • Korean Journal of Environmental Biology
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    • v.40 no.3
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    • pp.307-315
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    • 2022
  • In terms of habitat conservation, it is essential to develop a habitat assessment system that can evaluate not only the suitability of the current habitat, but also the health and stability of the habitat. This study aimed to develop a methodology of habitat quality assessment for endangered species by analyzing various existing habitat assessment methods. The habitat quality assessment consisted of selecting targeted species, planning of assessment, selecting targeted sites, assessing performance, calculating grade, and expert verification. Target sites were selected separately from core and potential habitats using a species distribution model or habitat suitability index. Habitat assessment factors were classified into ecological characteristic, landscape characteristic, and species-habitat characteristic. Ecological characteristic consisted of thirteen factors related to health of tree, vegetation, and soil. Landscape characteristic consisted of five factors related to fragment and connectivity of habitat. Species-habitat characteristic consisted of factors for evaluating habitat suitability depending on target species. Since meanings are different depending on characteristics, habitat quality assessment of this study could be used by classifying results for each characteristic according to various assessment purposes, such as designation of alternative habitats, assessment of restoration project, and protected area valuation for endangered species. Forest habitat quality assessment is expected to play an important role in conservation acts of endangered species in the future through continuous supplementation of this system in regard to quantitative assessment criteria and weighting for each factor with an influence.