• Title/Summary/Keyword: RW

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Patient-Specific Quality Assurance in a Multileaf Collimator-Based CyberKnife System Using the Planar Ion Chamber Array

  • Yoon, Jeongmin;Lee, Eungman;Park, Kwangwoo;Kim, Jin Sung;Kim, Yong Bae;Lee, Ho
    • Progress in Medical Physics
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    • v.29 no.2
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    • pp.59-65
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    • 2018
  • This paper describes the clinical use of the dose verification of multileaf collimator (MLC)-based CyberKnife plans by combining the Octavius 1000SRS detector and water-equivalent RW3 slab phantom. The slab phantom consists of 14 plates, each with a thickness of 10 mm. One plate was modified to support tracking by inserting 14 custom-made fiducials on surface holes positioned at the outer region of $10{\times}10cm^2$. The fiducial-inserted plate was placed on the 1000SRS detector and three plates were additionally stacked up to build the reference depth. Below the detector, 10 plates were placed to avoid longer delivery times caused by proximity detection program alerts. The cross-calibration factor prior to phantom delivery was obtained by performing with 200 monitor units (MU) on the field size of $95{\times}92.5mm^2$. After irradiation, the measured dose distribution of the coronal plane was compared with the dose distribution calculated by the MultiPlan treatment planning system. The results were assessed by comparing the absolute dose at the center point of 1000SRS and the 3-D Gamma (${\gamma}$) index using 220 patient-specific quality assurance (QA). The discrepancy between measured and calculated doses at the center point of 1000SRS detector ranged from -3.9% to 8.2%. In the dosimetric comparison using 3-D ${\gamma}$-function (3%/3 mm criteria), the mean passing rates with ${\gamma}$-parameter ${\leq}1$ were $97.4%{\pm}2.4%$. The combination of the 1000SRS detector and RW3 slab phantom can be utilized for dosimetry validation of patient-specific QA in the CyberKnife MLC system, which made it possible to measure absolute dose distributions regardless of tracking mode.

The effect of mixture ratios of worm cast and soil on the growth of Orchardgrass seedlings (지렁이 분립(糞粒)과 토양의 혼합비율이 Orchardgrass 유식물체(幼植物體)의 생육에 미치는 영향)

  • Lee, J.S.;Yoo, E.H.
    • Journal of the Korea Organic Resources Recycling Association
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    • v.1 no.2
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    • pp.267-274
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    • 1993
  • This experiment was carried out to determine the effect of mixture ratios of worm cast and soil on the growth orchardgrass seedlings, and estimate the adequate mixture ratio of worm cast for plant growth media. Mixture ratios of worm cast and soil were 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100, respectively. The results were summarized as follows; 1. The value of dry weight of shoot(SW), dry weight of root(RW), number of tillers per plant(NT) and biological yield(BY) were the highest in the mixture with 60% of worm cast. Particularly, the dry weight distribution to root in 20%-60% mixture ratios of worm cast were higher than those grown in 80%-100% mixture ratios of worm cast, it may due to the enhancement of root growth by adquate worm cast mix. 2. The orchardgrass seedlings in the 60% mixture ratio of worm cast grown in favourable soil conditions compared to those grown in other mixtrure ratios of worm cast and soil without worm cast. The soil analysis data showed that 60% mixture ratio of worm cast contained pH 6.16, 13.84% of organic matter, 0.84% of total nitrogen, 1,413.9ppm of available phosphorus and 16.7me/100g of cation exchange capacity, respectively. 3. Biological yield(BY) indicated positive significant correlation with the dry weights of shoot(SW) and root(RW). And, the dry weight of shoot(SW) had positive correlation with the number of tiller per plant(NT) and dry weight of tiller(WT).

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Polymorphism of Ghrelin Gene in Twelve Chinese Indigenous Chicken Breeds and Its Relationship with Chicken Growth Traits

  • Li, C.C.;Li, K.;Li, J.;Mo, D.L.;Xu, R.F.;Chen, G.H.;Qiangba, Y.Z.;Ji, S.L.;Tang, X.H.;Fan, B.;Zhu, M.J.;Xiong, T.A.;Guan, X.;Liu, Bang
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.2
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    • pp.153-159
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    • 2006
  • A 2,656 bp fragment of chicken ghrelin gene was cloned and SNPs were detected by PCR-RFLP and Allele Specific PCR (ASP) in 12 Chinese indigenous chicken breeds and a commercial chicken population. The results showed that there were 23 base variations and an amino acid change ($Gln{\rightarrow}Arg$) in cloned chicken ghrelin gene. Three SNPs were confirmed in 13 populations and associations between this gene and growth traits of Tibetan chicken (TC) and Recessive White chicken (RW) were investigated. The results of haplotype analysis revealed that 26 haplotype genotypes were composed of eight haplotypes. The results of $x^2$ tests indicated that there were significant differences between genotypes or haplotype genotype frequencies in some of the breeds or sexes at 0.05 or 0.01 levels. The results of ANOVA revealed that there were significant differences between genotypes or haplotype genotypes on some growth traits of TC and RW chicken breeds at 0.05 or 0.01 levels. Multiple comparisons showed that there were significant associations between genotype CT at site 71 and some growth traits of two chicken breeds and between genotype AG at site 1,215 and body weight at 16 wk of two chicken breeds, and there was a significant association between haplotype genotype CAA/CAG and body weight and shank girth at 16 wk of two chicken breeds.

Growth and Phytochemical Contents of Ice Plant as Affected by Light Quality in a Closed-type Plant Production System (완전제어형 식물생산시스템에서 광질에 따른 아이스플랜트의 생육과 기능성물질 함량)

  • Kim, Young Jin;Kim, Hye Min;Hwang, Seung Jae
    • Horticultural Science & Technology
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    • v.34 no.6
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    • pp.878-885
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    • 2016
  • A study was conducted to examine the effects of light quality on the growth and phytochemical contents of ice plant in a closed-type plant production system. Seeds were sown in a 128-cell plug tray using rockwool. The seedlings were then transplanted into a deep floating technique system with recirculating nutrient solution (EC $1.5dS{\cdot}m^{-1}$, pH 6.5) in a closed-type plant production system. The nutrient solution was supplied at two weeks after transplanting with 2.0 mM NaCl concentration in all treatments for the development of the bladder cells. The three light sources with different light qualities used were as followed; FL (fluorescent lamps), combined RW LED (red:white = 7:3), and combined RBW LED (red:blue:white = 8:1:1) at $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD with a photoperiod of 14/10 hours (light/dark). The results showed that the FL treatment had the greatest growth enhancement effects on the leaf area and the fresh and dry weights of the shoots and roots. The SPAD values were significantly higher under the FL and RBW LED treatments, at 29.8 and 30.6, respectively. No significant difference was observed in salinity under all treatments. Chlorophyll fluorescence was significantly higher under the FL treatment. The total phenol content and antioxidant activity were the highest under the RBW LED treatment. The total flavonoid content was significantly higher under the RBW LED and FL treatments. Hence, the results indicate that the growth of ice plant was maximized under the FL treatment. The phytochemical contents were maximized under the RBW LED treatment.

Polyphenol Contents and Antioxidant Activity of Lepista nuda (민자주방망이버섯의 폴리페놀 함량과 항산화활성)

  • Lee, Yang-Suk;Joo, Eun-Young;Kim, Nam-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.10
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    • pp.1309-1314
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    • 2006
  • This study analyzed the contents of vitamin C, polyphenol compounds, and evaluated the inhibitory activities against xanthine oxidase and tyrosinase of Lepista nuda extract prepared by the reflux and microwave-assisted methods. The vitamin C content of the fresh L. nude was $9.92{\pm}0.02$ mg/100 g. The content of phenolic compounds in the fresh L. nuda was $1.87{\pm}0.02\;mg/g$. The ethanol extracts prepared by reflux method and microwave-assisted method showed the highest phenol contents of $12.06{\pm}0.12\;mg/g\;and\;11.84{\pm}0.17\;mg/g$, respectively. The inhibitory rates on xanthine oxidase and tyrosinase of ethanol extracts prepared by the microwave assisted method showed the highest value of 99.78% and 30.30% at the concentration of $3,000{\mu}g/mL$. The inhibitory activities on xanthine oxidase and tyrosinase were increased depending on the extract concentration.

Polyphenol Contents and Physiological Activity of the Lespedeza bicolor Extracts (싸리 추출물의 폴리페놀 함량과 생리활성)

  • Lee, Yang-Suk;Joo, Eun-Young;Kim, Nam-Woo
    • Food Science and Preservation
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    • v.13 no.5
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    • pp.616-622
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    • 2006
  • This study was intended to analyze the contents of polyphenol compounds and vitamin C, and the inhibitory activities of xanthine oxidase and tyrosinase to measure physiological efface of various extract of Lespedeza bicolor. The vitamin C content was $26.42{\pm}0.08mg/100g$. The content of phenolic compounds included in the flesh L bicolor was $1.14{\pm}0.02mg/g$. The ethanol extract by reflux method and water extracts by the microwave-assisted method showed the highest content as 154.95 mg/g and 145.17 mg/g, respectively. The xanthine oxidase inhibitory tate of water extracts was the highest value of 87.85% at the concentration of 1,000 ug/mL. All kinds of extracts showed the highest inhibitory activity for the xanthine oxidase at the concentration of 1,000 ug/mL and a decreasing pattern of the inhibitory race over the concentration of 1,000 ug/mL. The tyrosinase inhibitory rate was increased with an increment of the extract concentrations, and the activity of ethanol extracts was the highest as 55.22% at the concentration of 3,000 ug/mL.

The Crystal Structure of Tris(ethylenediamine)nickel(II)-dichromate, $[Ni(C_2N_2H_8)_3]\cdotCr_2O_7$ ($[Ni(C_2N_2H_8)_3]\cdotCr_2O_7$의 결정구조)

  • Kim, Se-Hwan;Kim, Seung-Bin;Nam, Gung-Hae
    • Korean Journal of Crystallography
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    • v.7 no.1
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    • pp.36-43
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    • 1996
  • The crystal structure Tris(ethylenediamine)nickel(II)Dichromate has been determined by X-ray crystallography. Crystal data: a=8.268(2), b=13.865(2), c=14.921(2)Å, γ=102.04(2)°, V=1672.9(5)Å3, Z=4, Monocline, P21/b (space group No.=14), Dcalc=1.806 gcm-3, μ=24.05 cm-0.1. The intensity data were collected with Mo-Kα radiation(λ=0.7107Å) on an automatic four-circle diffractometer with a graphite monochromator. The structure was solved by Patterson method and refined by full matrix least-square methods using unit weights. The final R and S values were R=0.045, Rw=0.051, Rall=0.059 and S=2.171for 2248 observed reflections. The two carbon atoms of a ring of Ni(en)-ion were split into crossed four atoms. In consideration of α- and β-angles of two rings of a disordered ethylenediamine of Nien3-ion and the hydrogen bonds between Ni(en)3-cation and Cr2O7-anion, the configuration of Ni(en)3-ion is assumed to be disordered with Λδδδ and Λδδλ.

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Improving Moisture Retention Capacity of Pine Bark by Grinding and Blending with Recycled Rockwool (분쇄와 폐암면의 혼합에 의한 소나무 수피의 보수성 증진)

  • Choi, Jong-Myung;Chung, Hae-Joon;Choi, Jong-Seung
    • The Journal of Natural Sciences
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    • v.11 no.1
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    • pp.131-135
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    • 1999
  • The objective of this research was to improve moisture retention capacity of pine bark. To achieve this, barks were ground with Wiley mill of hammer mill and were blended with recycled rockwool. Then, changes of soil physical properties were determined. The percentage of particles larger than 5.6 mm was 86.5% in raw materials. The percentage of particles larger than 1 mm decreased and those of particles smaller than 1 mm increased by grinding with Wiley mill or hammer mill. Grinding with Wiley mill showed better effect than those of hammer mill in decreasing particle size distribution. Grinding resulted in decreased total porosity (TP) and air space (AS) and increased container capacity (CC) and residual water content (RW), indication improved moisture retention capacity. The material ground with Wiley mill, than blended with 50% recycled rockwool had 81.1%, 67.7%, 13.5% and 235 ml in TP, CC, AS and RW, respectively. These results indicated that moisture retention capacity was improved by blending with recycled rockwood, but aeration of root media was much better than those of peat+vermiculite(1:1, v/v), which is commonly used in commercial production.

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Geant4 Code Based Simulation of 6 MV Photon Beam for Analysis of Dose Distribution (Geant4 코드를 이용한 선형가속기 6 MV 광자선의 선량분포에 관한 연구)

  • Lee, Jun-Seong;Kim, Yang-Soo;Lee, Sun-Young
    • Journal of radiological science and technology
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    • v.45 no.5
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    • pp.449-455
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    • 2022
  • This study is to present a Geant4 code for the simulation of the absorbed dose distribution given by a medical linac for 6 MV photon beam. The dose distribution was verified by comparison with calculated beam data and beam data measured in water phantom. They were performed for percentage depth dose(PDD) and beam profile of cross-plane for two field sizes of 10 × 10 and 15 × 15 cm2. Deviations of a percentage and distance were obtained. In energy spectrum, the mean energy was 1.69 MeV. Results were in agreement with PDD and beam profile of the phantom with a tolerance limit. The differences in the central beam axis data 𝜹1 for PDD had been less than 2% and in the build up region, these differences increased up to 4.40% for 10 cm square field. The maximum differences of 𝜹2 for beam profile were calculated with a result of 4.35% and 5.32% for 10 cm, 15 cm square fields, respectively. It can be observed that the difference was below 4% in 𝜹3 and 𝜹4. For two field sizes of 𝜹50-90 and RW50, the results agreed to within 2 mm. The results of the t-test showed that no statistically significant differences were found between the data for PDD of 𝜹1, p>0.05. A significant difference on PDD was observed for field sizes of 10 × 10 cm2, p=0.041. No significant differences were found in the beam profile of 𝜹3, 𝜹4, RW50, and 𝜹50-90. Significant differences on beam profile of 𝜹2 were observed for field sizes of 10 × 10 cm2, p=0.025 and for 15 × 15 cm2, p=0.037. This work described the development and reproducibility of Geant4 code for verification of dose distribution.

Analysis of Regional Economic Ripple Effects of Port Logistics Industry in Gwangyang City - Focusing on Exogenous Specified Input-Output Model - (광양시 항만물류산업의 지역경제 파급효과 분석 - 외생화 산업연관모형을 중심으로 -)

  • Kim, Min-Seong;Na, Ju-Mong
    • Journal of Korea Port Economic Association
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    • v.39 no.2
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    • pp.77-95
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    • 2023
  • The regional infrastructure industries of Gwangyang City, the subject of this study, are Gwangyang Port and Gwangyang Steel Mill. Therefore, it is necessary to analyze the regional economic ripple effects of the port logistics industry in Gwangyang City. In this study, a multi-stage approach using the RW and the LQ methodology using the national input-output tables in 2015 and 2019 is used to prepare the regional interindustry analysis chart in Gwangyang City, and an exogenous demand induction model that reclassified the port logistics industry was applied. Through this, the purpose of this study was to provide policy implications by figuring out the regional economic ripple effects of the port logistics industry quantitatively in Gwangyang City. As a result of the analysis, the industries with high production inducement effect and forward/backward linkage effect of the port logistics industry in Gwangyang City were analyzed as manufacturing, transportation, land and air logistics sectors. And the industries in which the added value inducement effect and the employment inducement effect were analyzed as an industry related to the service industry. Therefore, it is necessary to prepare support measures to foster the port logistics industry as a way to promote these industries and revitalize the local economy of Gwangyang City. To this end, it is desirable to improve policies and systems for the vitalization of the Gwangyang port maritime cluster and provide various policy support for the port logistics industry in Gwangyang City. This study is meaningful in suggesting policy implications for the regional economy of Gwangyang City based on the results of exogenous analysis of the port logistics industry in small and medium-sized cities. However, It seems that further studies related to this will be needed in the future.