• Title/Summary/Keyword: 안정성도

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A Survey on Radiation Exposure of Patient in Mammography (유방 X선촬영 시 피폭선량에 대한 조사 연구)

  • Kim, Hyung-Chul;Cho, Pyung-Gon;Kim, Sung-Soo;Choi, Jong-Hak;Kim, You-Hyun
    • Journal of radiological science and technology
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    • v.27 no.4
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    • pp.55-60
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    • 2004
  • The purpose of this study was to examine both patient exposure dose during mammography and the utility status of mammograpy equipments. The data of this study were collected through questionnaire survey for 278 medical facilities registered at Korean Hospital Association and finally 161 medical facilities's data were analyzed. According to data analysis, medical facilities of 14.9% used the average glandular dose of less than 0.5 mGy, $0.51{\sim}1.0\;mGy$ 8.6%, $1.01{\sim}1.5\;mGy$ 14.9%, $1.51{\sim}2.0\;mGy$ 11.1%, $2.01{\sim}2.5\;mGy$ 9.8%, $2.51{\sim}3.0\;mGy$ 33.3%, and 7.4% more than 3.01 mGy. It was found that medical facilities of 92.6% used less than 3 mGy, showing that this figure is similar to the limit value of 3 mGy recommended by Korea Food & Drug Administration(KFDA). Recently, international organizations such as ICRP associated with radiation protection suggests that less than 3 mGy of average mammary gland dose be used during mammography in case of using Mo target+Mo filter, film/screen system and craniocaudal projection with the breast pressed to 4.2 cm. The standard dose is being strictly observed and that of the limits is going down to 2 mGy or 1.5 mGy. The major results of this study indicate that interests and a counterplan to reduce patient dose during mammography should be considered. Based on this study, the authors of this study will continue to measure exposure dose to set a new standard for patient exposure dose during mammography.

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Priority Order of Decisional Factors and Conceptual Construct of Security Martial Arts' Spirit (경호무도 정신특성 요인의 상대적 중요도 평가)

  • Kim, Dong-Hyun
    • Korean Security Journal
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    • no.32
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    • pp.7-32
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    • 2012
  • This study aimed to evaluate the relative status using Analytic Hierarchy Process(AHP) on the spiritual factors of the security martial arts for the guards to perform the best security service. There were 540 participants who were students majored in security martial arts, workers for security and specialists of practical and theoretical security martial arts for this study. The exploratory and confirmatory factor analysis were carried out using the selecting data through literature reviews in the level of the factor-extraction about the spiritual characteristics. The specialists' survey was conducted on the relative status among factors using the spiritual concept structure based on the studied above. Selected data was calculated with SPSS 18.0 for windows, AMOS 5.0, and Expert Choice 2000 software. The conclusion can be made through those process above. First, 4 general factors and 20 detailed factors were found as the result of the factor exploration related to the spiritual characteristics of the security martial arts. The result which was verified on Construction validity of searched factors had stable figures on every standard. In other words, the participants for survey on this study "Spiritual characteristic concepts of the security martial arts" can be evaluated it is valid. The general factors of security martial arts' spirit were conceptualized with Psychological spirit, ethical spirit, martial art spirit, practical spirit through the naming process on the general factors of the security martial arts' spiritual characteristic concepts. The detailed factors of security martial arts' spirit were concentration, self-confidence, self-management, immersion, self-esteem in psychological spirit and sacrifice, justice, royalty, peace, sense of duty in ethical spirit and courtesy, toughness, defense, balance of mind and body, bravery in martial arts and responsibility, cooperation, modesty, determination, professionalism in practical spirit of security martial arts. That is, the conceptualization of security martial arts' spirit was verified that it had validity. Second, the hierarchical model of the security martial arts was composed with 4 superordinate concepts and 20 subordinate concepts. As the result of evaluating relative status based on Spiritual characteristics-hierarchy model, the impotance was proven in order of ethical spirit(.482), martial art spirit(.248), practical spirit(.188), psychological spirit(.083). Also the importance related to spiritual characteristics of security martial arts on subordinate concepts was proven in order of sacrifice(.252), courtesy(.110), sense of duty(.108), responsibility(. 073), royalty(.053), toughness(.052), justice(.049), defense(.038), professionalism(.038), determination(.035), cooperation(.029), self-confidence (.026), bravery(.025), self-esteem(.024), balance of mind and body(.023), peace(.019), concentration(.014), modesty(.013), self-management(.011), flow (.007). To sum up, the spiritual factor related to ethics such as sacrifice, justice, royalty, peace, sense of duty was the most important for the security martial arts.

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Stereotactic Target Point Verification in Actual Treatment Position of Radiosurgery (방사선수술시 두개내 표적의 정위적좌표의 치료위치에서의 확인)

  • Yun, Hyong-Geun;Lee, Hyun-Koo
    • Radiation Oncology Journal
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    • v.13 no.4
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    • pp.403-409
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    • 1995
  • Purpose : Authors tried to enhance the safety and accuracy of radiosurgery by verifying stereotacitc target point in actual treatment position prior to irradiation. Materials and Methods : Before the actual treatment, several sections of anthropomorphic head phantom were used to create a condition of unknown coordinates of the target point. A film was sandwitched between the phantom sections and punctured by sharp needle tip. The tip of the needle represented the target point. The head phantom was fixed to the stereotactic ring and CT scan was done with CT localizer attached to the ring. After the CT scanning, the stereotactic coordinates of the target point were determined. The head phantom was secured to accelerator's treatment couch and the movement of laser isocenter to the stereotactic coordinates determined by CT scanning was performed using target positioner. Accelerator's anteroposterior and lateral portal films were taken using angiographic localizers. The stereotactic coordinates determined by analysis of portal films were compared with the stereotactic coordinates previously determined by CT scanning. Following the correction of discrepancy the head phantom was irradiated using a stereotactic technique of several arcs. After the irradiation, the film which was sandwitched between the phantom sections was developed and the degree of coincidence between the center of the radiation distribution with the target point represented by the hole in the film was measured. In the treatment of the actual patients, the way of determining the stereotactic coordinates with CT localizers and angiograuhic localizers was the same as the phantom study. After the correction of the discrepancy between two sets of coordinates, we proceeded to the irradiation of the actual patient. Results : In the phantom study, the agreement between the center of the radiation distribution and the localized target point was very good. By measuring optical density profiles of the sandwitched film along axes that intersected the target point, authors could confirm the discrepancy was 0.3 mm. In the treatment of an actual patient, the discrepancy between the stereotactic coordinates with CT localizers and angiographic localizers was 0.6 mm. Conclusion : By verifying stereotactic target point in actual treatment position prior to irradiation, the accuracy and safety of streotactic radiosurgery procedure were established.

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Evaluation of Future Water Deficit for Anseong River Basin Under Climate Change (기후변화를 고려한 안성천 유역의 미래 물 부족량 평가)

  • Lee, Dae Wung;Jung, Jaewon;Hong, Seung Jin;Han, Daegun;Joo, Hong Jun;Kim, Hung Soo
    • Journal of Wetlands Research
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    • v.19 no.3
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    • pp.345-352
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    • 2017
  • The average global temperature on Earth has increased by about $0.85^{\circ}C$ since 1880 due to the global warming. The temperature increase affects hydrologic phenomenon and so the world has been suffered from natural disasters such as floods and droughts. Therefore, especially, in the aspect of water deficit, we may require the accurate prediction of water demand considering the uncertainty of climate in order to establish water resources planning and to ensure safe water supply for the future. To do this, the study evaluated future water balance and water deficit under the climate change for Anseong river basin in Korea. The future rainfall was simulated using RCP 8.5 climate change scenario and the runoff was estimated through the SLURP model which is a semi-distributed rainfall-runoff model for the basin. Scenario and network for the water balance analysis in sub-basins of Anseong river basin were established through K-WEAP model. And the water demand for the future was estimated by the linear regression equation using amounts of water uses(domestic water use, industrial water use, and agricultural water use) calculated by historical data (1965 to 2011). As the result of water balance analysis, we confirmed that the domestic and industrial water uses will be increased in the future because of population growth, rapid urbanization, and climate change due to global warming. However, the agricultural water use will be gradually decreased. Totally, we had shown that the water deficit problem will be critical in the future in Anseong river basin. Therefore, as the case study, we suggested two alternatives of pumping station construction and restriction of water use for solving the water deficit problem in the basin.

Meat Quality Comparison of Beef from Hanwoo Supplemented with Dietary Rhus verniciflua Stokes Meal, Silicate, and Chromium-Methionine during Refrigerated Storage (옻나무 분말, 규산염 및 크롬메티오닌을 급여한 한우육의 냉장저장 중 육질 비교)

  • Kang, Sun-Moon;Lee, Ik-Sun;Song, Young-Han;Lee, Sung-Ki
    • Food Science of Animal Resources
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    • v.28 no.2
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    • pp.138-145
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    • 2008
  • This study was carried out to compare the meat quality of beef from Hanwoo supplemented with dietary Rhus verniciflua Stokes (RVS) meal, silicate (Si), and chromium-methionine (Cr-Met) during refrigerated storage. The 26 mon-aged Hanwoo steers were fed basal diets containing 4% RVS, 4% RVS+400 ppm Cr-Met, 1.4% $SiO_2$, or 0.14% $SiO_2+400 ppm$ Cr-Met for 4 mon prior to slaughter. The M. longissimus from carcasses were then stored at $4{\pm}0.2^{\circ}C$ for 7 d. The crude fat content was higher in the Si and Si+Cr-Met groups (p<0.05). The water-holding capacity (WHC) and tenderness were highest in the Si+Cr-Met group (p<0.05). With regard to fatty acids, the polyunsaturated fatty acid (PUFA) content was lower in the Si and Si+Cr-Met groups (p<0.05), and the monounsaturated fatty acid (MUFA) content was lowest in the Si+Cr-Met group (p<0.05). The TBARS and MetMb contents were decreased in the Si, Si+Cr-Met, and RVS+Cr-Met groups. Regarding meat color during storage, the Si+Cr-Met group showed the highest L, a, b, C values and total color, and those of the Si and RVS+Cr-Met groups were higher than the RVS group (p<0.05). Consequently, beef from Si-fed Hanwoo had higher fat content, color and oxidation stability, and lower PUFA content than RVS-fed beef. And beef from Si+Cr-Met-fed Hanwoo had higher WHC, tenderness and color stability, and lower MUFA content than Si-fed beef.

X-ray Absorption Spectroscopy Study on Surface Interaction of Arsenite onto Two-Line Ferrihydrite at pHs 4 and 10 (pH 4와 10에서의 3가 비소와 Two-Line Ferrihydrite의 표면반응에 대한 X선 흡수 분광 연구)

  • Lee, Woo-Chun;Choi, Sun-Hee;Cho, Hyen-Goo;Kim, Soon-Oh
    • Journal of the Mineralogical Society of Korea
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    • v.24 no.2
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    • pp.73-82
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    • 2011
  • X-ray absorption spectroscopy (XAS) study was conducted using arsenite-sorbed two-line ferrihydrite to investigate the mechanism of surface interactions between two-line ferrihydrite and As(III) (arsenite) which are ubiquitous in nature. The two-line ferrihydrite used was synthesized in the laboratory and the study was undertaken at pHs 4 and 10 to compare the difference in mechanisms of surface interaction between acidic and alkaline environments. The effect of arsenite-adsorbed concentrations on surface complexation was investigated at each pH condition as well. From the results of XAS analyses, the structural parameters of arsenite in the EXAFS revealed that the coordination number and distanceof As-O were 3.1~3.3 and 1.74~1.79 ${\AA}$, respectively, which indicate that the unit structure of arsenite complex formed on the surface of two-line ferrihydrite is $AsO_3$. The dominant structures of As(III)-Fe complex were examined to be bidentate binuclear comer-sharing ($^2C$) and the mixture of bidentate mononuclear edge sharing ($^2E$) and $^2C$ appeared as well. At pH 4, arsenite complex showed different structures on the surface of two-line ferrihydrite, depending on the adsorbed concentrations. At pH 10, on the contrary, the surface structures of arsenite complexes were interpreted to be almost identical, irrespective of the adsorbed concentrations of arsenite. Consequently, this microscopic XAS results support the results of macroscopic adsorption experiments in which the surface interaction between arsenite and two-line ferrihydrite is significantly influenced by pH conditions as well as arsenite concentrations.

Adsorption of Arsenic on Goethite (침철석(goethite)과 비소의 흡착반응)

  • Kim, Soon-Oh;Lee, Woo-Chun;Jeong, Hyeon-Su;Cho, Hyen-Goo
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.3
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    • pp.177-189
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    • 2009
  • Iron (oxyhydr)oxides commonly form as secondary minerals of high reactivity and large surface area resulting from alteration and weathering of primary minerals, and they are efficient sorbents for inorganic and organic contaminants. Accordingly, they have a great potential in industrial applications and are also of substantial interest in environmental sciences. Goethite (${\alpha}$-FeOOH) is one of the most ubiquitous and stable forms of iron (oxyhydr)oxides in terrestrial soils, sediments, and ore deposits, as well as a common weathering product in rocks of all types. This study focused on adsorption reaction as a main mechanism in scavenging arsenic using goethite. Goethite was synthesized in the laboratory to get high purity, and a variety of mineralogical and physicochemical features of goethite were measured and related to adsorption characteristics of arsenic. To compare differences in adsorption reactions between arsenic species, in addition, a variety of experiments to acquire adsorption isotherm, adsorption edges, and adsorption kinetics were accomplished. The point of zero charge (PZC) of the laboratory-synthesized goethite was measured to be 7.6, which value seems to be relatively higher, compared to those of other iron (oxyhydr)oxides. Its specific surface area appeared to be $29.2\;m^2/g$ and it is relatively smaller than those of other (oxyhydr)oxides. As a result, it was speculated that goethite shows a smaller adsorption capacity. It is likely that the affinity of goethite is much more larger for As(III) (arsenite) than for As(V) (arsenate), because As(III) was observed to be much more adsorbed on goethite than As(V) in equivalent pH conditions. When the adsorption of each arsenic species onto goethite was characterized in various of pH, the adsorption of As(III) was largest in neutral pH range (7.0~9.0) and decreased in both acidic and alkaline pH conditions. In the case of As(V), the adsorption appeared to be highest in the lowest pH condition, and then decreased with an increase of pH. This peculiarity of arsenic adsorption onto goethite might be caused by macroscopic electrostatic interactions due to variation in chemical speciation of arsenic and surface charge of goethite, and also it is significantly affected by change in pH. Parabolic diffusion model was adequate to effectively evaluate arsenic adsorption on goethite, and the regression results show that the kinetic constant of As(V) is larger than that of As(III).

Studies on the Selective Separation and Preconcentration of Cr(VI) Ion by XAD-16-Chromotropic Acid Chelating Resin (XAD-16-Chromotropic Acid 킬레이트 수지에 의한 몇 가지 금속이온의 선택적 분리 및 농축에 관한 연구)

  • Lee, Won;Lee, Chang-Youl;Kim, Mi-Kyoung;Kim, In-Whan
    • Analytical Science and Technology
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    • v.17 no.3
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    • pp.199-210
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    • 2004
  • A new polystyrene-divinylbenzene chelating resin containing 4,5-dihydroxy-naphthalene-2,7-disulfonic acid (chromotropic acid : CTA) as functional group has been synthesized and characterized. The sorption and desorption properties of this chelating resin for Cr(III) ion and Cr(VI) ion including nine metal bloodstain. As a results, FOB test kit could be effectively applied to identification of human blood at chelating resin was stable in acidic and alkaline solution. The Cr(VI) ion is selectively separated from Cr (III) ion at pH 2 and the maximum sorption capacity of Cr(VI) ion is 1.2 mmol/g. In the presence of anions such as $F^-$, $SO{_4}^{2-}$, $CN^-$, $CH_3COO^-$, $NO{_3}^-$, the sorption of Cr(VI) ion was reduced but anions such as $PO{_4}^{3-}$ and $Cl^-$ revealed no interference effect. The elution order of metal ions obtained from breakthrough capacity and overall capacity at pH 2 was Cr(VI)>Sn(II)>Fe(III)>Cu(II)>Cd(II)${\simeq}Pb(II){\simeq}Cr(III){\simeq}Mn(II){\simeq}Ni(II){\simeq}Al(III)$. Desorption characteristics for Cr(VI) ion was investigated with desorption agents such as $HNO_3$, HCl, and $H_2SO_4$. It was found that the ion showed high desorption efficiency with 3 M HCl. As the result, the chelating resin, XAD-16-CTA was successfully applied to separation and preconcentration of Cr (VI) ion from several metal ions in metal finishing works.

Development of Optimal Culture Media for the Stable Production of Mushroom (버섯의 안정적 생산을 위한 최적배지의 개발)

  • Gal, Sang-Wan;Lee, Sang-Won
    • Applied Biological Chemistry
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    • v.45 no.2
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    • pp.71-76
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    • 2002
  • Several antagonistic bacteria, SD-1, 4, 10, 11, 14, 15, and 16, which have strong CMCase and amylase activities, were isolated from the fermented mushroom media. Among them, SD-1, 10, 11, and 15 have strong antibacterial activities against the mushroom pathogenic bacteria Pseudomonas sp., and SD-1, 10, 11, 14, and 16 have strong antifungal activities against the mushroom pathogenic fungi, Trichoderma sp. SD-14, 15, and 16 did not inhibit the growth of mushroom Pleurotus eryngii ASI-2302, and Pleurotus ostreatus ASI-2042 and ASI-2180. When the culture broth mixture of the seven bacterial strains was applied to the mushroom media, the growths of pathogens, Pseudomonas sp. and Trichoderma sp., were inhibited.

Mineral Identification and Field Application by Short Wave Infrared (SWIR) Spectroscopy (단파장적외선 분광분석법을 이용한 광물동정과 현장적용성)

  • Kim, Chang Seong;Kim, Yong-Hwi;Choi, Seon-Gyu;Ko, Kwang-Beom;Han, Kyeong-Soo
    • Economic and Environmental Geology
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    • v.50 no.1
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    • pp.1-14
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    • 2017
  • The analytical conditions including surface state, moisture effect, and device condition were investigated for applying Short Wave Infrared(SWIR) spectroscopy to the field survey. Among the three surface state of samples (exposed surface, cutting face and powder), both spectra from the exposed surface and cutting face are almost identical whereas spectral variation was detected in powder sample. Over 24-hours-dryring of the wet sample at room temperature, the samples show a similar spectrum with that of dry condition. The result suggests that outcrop samples mighty be dried for 24 ~ 48 hours depending on the wetness of outcrop. The bright minerals could produce stable spectra with 10 times measurements as default value of the device under SWIR spectroscopy but the dark minerals would require about 10 seconds, which corresponds to 100 times measurements to get the reliable spectra. The position and shape 2,160 ~ 2,330 nm and/or other spectral features of hydrothermal alteration minerals by SWIR spectroscopy could be used for a classification of hydrothermal alteration zone in the field. Absorption peaks in 2,160 ~ 2180 nm are useful for identifying (advanced) argillic zone by spectral characteristics of kaoline, dickite, pyrophyllite, and alunite. Absorption peaks in 2,180 ~ 2,230 nm are able to define muscovite, sericite, and smectite, which are key alteration minerals in phyllic zone. Absorption peaks in 2,230 ~ 2,270 nm can be used to recognize prophylitic zone where chlorite and epidote occur. Absorption peaks of other principle minerals such as talc, serpentine, amphibole, and carbonate group are mainly detected within the wave length of 2,270 ~ 2,330 nm. This result indicates that the spectra of these minerals need to be carefully interpreted.