• The Journal of Korean Society for Radiation Therapy
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• v.28 no.2
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• pp.109-121
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• 2016

To verify the accuracy of the image guided radiotherapy using ExacTrac 6D couch, the error values in six directions are randomly assigned and corrected and then the corrected values were compared with CBCT image to check the accurateness of ExacTrac. The therapy coordination values in the Rando head Phantom were moved in the directions of X, Y and Z as the translation group and they were moved in the directions of pitch, roll and yaw as the rotation group. The corrected values were moved in 6 directions with the combined and mutual reactions. The Z corrected value ranges from 1mm to 23mm. In the analysis of errors between CBCT image of the phantom which is corrected with therapy coordinate and 3D/3D matching error value, the rotation group showed higher error value than the translation group. In the distribution of dose for the error value of the therapy coordinate corrected with CBCT, the restricted value of dosage for the normal organs in two groups meet the prescription dose. In terms of PHI and PCI values which are the dose homogeneity of the cancerous tissue, the rotation group showed a little higher in the low dose distribution range. This study is designed to verify the accuracy of ExacTrac 6D couch using CBCT. It showed that in terms of the error value in the simple movement, it showed the comparatively accurate correction capability but in the movement when the angle is put in the couch, it showed the inaccurate correction values. So, if the body of the patient is likely to have a lot of changes in the direction of rotation or there is a lot of errors in the pitch, roll and yaw in ExacTrac correction, it is better to conduct the CBCT guided image to correct the therapy coordinate in order to minimize any side effects.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.636-644
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• 2019

The purpose of this study was to investigate the callings of nocturnal birds using bioacoustic recording technology to identify species and to analyze the ecological characteristics of each species. Three sites - Seoraksan National Park, National Institute of Ecology, and Mudeungsan National Park - were investigated. The investigation period was from the middle of April 2018 to early March 2019 for Seoraksan national park, from late February of 2018 to the middle of February 2019 for the National Institute of Ecology, and from the middle of February 2018 to the end of August 2018 for Mudeungsan National Park. The main research results are as follows. Firstly, nocturnal bird species identified by the survey included Caprimulgus indicus, Otus sunia, Zoothera aurea, Bubo bubo, and Strix uralensis, 5 species in total. Secondly, the breeding call period of each species was from early May to early August for C. indicus, from early April to the end of September for O. sunia, from early March to early October for Z. aurea, from late September to early February for B. bubo, and from mid-January to early March for S. uralensis. Thirdly, the mating call rhythm was between 16:00 and 10:00 on the following day for all the observed species in the three regions, and the peak time zone was from 20:00 to 06:00 on the following day. Fourthly, there was no correlation between the cumulative call frequency and the precipitation for each species. Fifthly, the mean temperature during the period when the specific calls of nocturnal birds were detected was -4.00 ℃ for S. uralensis, 2.58 ℃ for B. bubo, 13.66 ℃ for Z. aurea, 19.50 ℃ for O. sunia, and 20.77 ℃ for C. indicus. The ANOVA results showed that there was a significant difference in mean temperature for the calling by species and that the mean temperature was S. uralensis, B. bubo, Z. aurea, and O. sunia-C. indicus, in the ascending order, for 4 groups in total. The period of the specific mating calls confirmed by the study is a period in which the frequency of calls was the highest among the periods when the specific calls were detected. Since it is associated with the known mating period of each species, the period of the high frequency of calls confirmed by the bioacoustic monitoring can be regarded as the mating season. This study is meaningful in that it is the early research that has used the bioacoustic recording technology to identify species and ecological characteristics of species of nocturnal birds in Korea.

• The Mathematical Education
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• v.16 no.2
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• pp.22-26
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• 1978

It is shown that a map having an extension to an open map between the Alex-androff base compactifications of its domain and range has a unique such extension. J.S. Wasileski has introduced the Alexandroff base compactifications of Hausdorff spaces endowed with Alexandroff bases. We introduce a definition of morphism between such spaces to obtain a category which we denote by ABC. We prove that the Alexandroff base compactification on objects can be extended to a functor on ABC and that the compact objects give an epireflective subcategory of ABC. For each topological space X there exists a completely regular space $\alpha$X and a surjective continuous function $\alpha$$_{x}$ : Xlongrightarrow$\alpha$X such that for each completely regular space Z and g$\in$C (X, Z) there exists a unique g$\in$C($\alpha$X, 2) with g=g$^{\circ}$$\beta$$_{x}$. Such a pair ($\alpha$$_{x}$, $\alpha$X) is called a completely regularization of X. Let TOP be the category of topological spaces and continuous functions and let CREG be the category of completely regular spaces and continuous functions. The functor $\alpha$ : TOPlongrightarrowCREG is a completely regular reflection functor. For each topological space X there exists a compact Hausdorff space $\beta$X and a dense continuous function $\beta$x : Xlongrightarrow$\beta$X such that for each compact Hausdorff space K and g$\in$C (X, K) there exists a uniqueg$\in$C($\beta$X, K) with g=g$^{\circ}$$\beta$$_{x}$. Such a pair ($\beta$$_{x}$, $\beta$X) is called a Stone-Cech compactification of X. Let COMPT$_2$ be the category of compact Hausdorff spaces and continuous functions. The functor $\beta$ : TOPlongrightarrowCOMPT$_2$ is a compact reflection functor. For each topological space X there exists a realcompact space (equation omitted) and a dense continuous function (equation omitted) such that for each realcompact space Z and g$\in$C(X, 2) there exists a unique g$\in$C (equation omitted) with g=g$^{\circ}$(equation omitted). Such a pair (equation omitted) is called a Hewitt's realcompactification of X. Let RCOM be the category of realcompact spaces and continuous functions. The functor (equation omitted) : TOPlongrightarrowRCOM is a realcompact refection functor. In [2], D. Harris established the existence of a category of spaces and maps on which the Wallman compactification is an epirefiective functor. H. L. Bentley and S. A. Naimpally [1] generalized the result of Harris concerning the functorial properties of the Wallman compactification of a T$_1$-space. J. S. Wasileski [5] constructed a new compactification called Alexandroff base compactification. In order to fix our notations and for the sake of convenience. we begin with recalling reflection and Alexandroff base compactification.

• Analytical Science and Technology
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• v.15 no.5
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• pp.417-426
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• 2002

Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.581-587
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• 2017

This study was based on the data of total mineral content of about 99% at the age of 16-26 years, we aimed at female university students who are important for bone formation in their early 20s. The purpose of this study was to investigate factors of eating habits affecting their bone density and to provide data to prevent osteoporosis which might occur in the future. It was conducted on 100 female university students in their 20s, the bone mineral density according to BMI was measured by DEAX, and the analysis of 10 eating habits items and the results of BMD measurement on their own results in Excel 2010. As a result, the height was $161.08{\pm}4.70cm$, the weight was $52.43{\pm}6.43kg$, and the BMI was $20.22{\pm}2.48$, which correlated with BMD (p<0.05). According to the BMI classification, 20 had low weight and 80 had normal weight, and BMD was $0.20{\pm}0.41$ at normal weight. In the same sex, the mean T-score of the young adult group was $-0.04{\pm}0.99$ compared with the BMD of the young adult group, and the mean Z-score of the same age group was $0.02{\pm}0.93$ (p<0.001). Eating habits affecting bone mineral density were significantly affected by 3 meals per day, 1-3 cups of coffee per day and p<0.05 for Low salt formula intake. 6-9 dairy product intake was also p<0.05 but not significant. Therefore, it is considered that when 20s female students become middle-aged woman, they should have proper eating habits so that osteogenesis can be improved at young age in order to prevent bone disease.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.4
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• pp.30-40
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• 2021

This study developed quantitative models to estimate the rainfall interception by seven native landscape tree species based on throughfall measurements. The tree species considered in this study were Abies holophylla, Acer palmatum, Ginkgo biloba, Pinus densiflora, Pinus koraiensis, Prunus yedoensis, and Zelkova serrata, which are frequently planted in the Korea. Among these species, 35.8% of the annual precipitation was intercepted by P. koraiensis, 34.1% by A. holophylla, 31.0% by Z. serrata, 27.6% by P. densiflora, 26.9% by G. biloba, 18.6% by A. palmatum, and 18.4% by P. yedoensis. All the quantitative models showed high fitness with r² values of 0.90-0.99. The annual rainfall interception from a tree with DBH of 20 cm were greatest with Z. serrata (5.1 m³/yr), followed by P. koraiensis (4.1 m³/yr), A. holophylla (3.1 m³/yr), G. biloba (2.8 m³/yr), P. densiflora (2.1 m³/yr), P. yedoensis (1.9 m³/yr), and A. palmatum (1.8 m³/yr) in order. Thus, evergreen tree species or those with a relatively high crown density were more effective in intercepting rainfall. In particular, the annual rainfall interception by Z. serrata was the greatest because its crown area, volume, and density were higher than those of the other species. This study pioneers in quantifying annual rainfall interception for landscape tree species in Korea. The study results can be useful for evaluating rainfall interception by landscape trees in urban greenspace design for governments and corporations.

• Journal of Life Science
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• v.30 no.12
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• pp.1109-1117
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• 2020

In order to verify whether Zophobas atratus is an edible insect, the nutrients and harmful substances of Z. atratus larvae reared with an artificial diet (AD) and wheat bran (WB) were compared and analyzed. Based on dry weight, the crude protein content of Z. atratus larvae reared with an AD was 62.4%, 1.4 times higher than that of those reared with WB (45.2%). The crude fat content was 20.5% in the AD group, 2.3 times less than in the WB group (46.3%). The leucine content was 1.4 times higher in the AD group (4.2%) than in the WB group (3.0%). The glutamic acid content of nonessential amino acids was 1.3 times higher in the AD group (7.0%) than in the WB group (5.3%). The oleic acid content was 1.4 times higher in the WB group (37.0%) than in the AD group (26.7%). The potassium content was 1.1 times higher in the AD group (975.9 mg/100 g) than in the WB group (872.9 mg/100 g). According to the results of the toxic substances analysis, the lead and cadmium levels of the WB and AD groups were standard for edible insects. Pathogenic microorganisms, such as E. coli and salmonella, were not detected in either group. According to the results of the present analysis of nutrition and harmful substances, Z. atratus larvae raised on an AD are safe and contain various nutrients. Therefore, such larvae could be useful sources of food and feed.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.87-96
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• 1995

We examined the effects of seed treatment on field germination rate and seedling growth for four woody species, Euonymus alatus, Thea sinensis, Zanthoxylum piperitum, Nandina domestia which are economically useful in Korea. The seeds of each species were purified carefully after collection during Oct. and Nov.. E. alatus, T. sinensis, and Z. piperitum were sowed in the experimental field after stored in open ground with treatment of Pon-Pon. $H_2O_2$, $GA_3$, scarification. and N. domestica was sowed in container within green house after treatment of three different periods(7, 15, 21days) in growth chamber(4, 25, $32^{\circ}C$). Germination rate and seedling growth were measured in mid-Oct.. In E. alatus germination rate was higher in storaging in open ground after soaking in $GA_3$(67.1%) than in only storaging in open ground(18.4%). But the rate in T. sinensis showed no differences between storage in open ground after treatment of $GA_3$, and scarification, and only storage in open ground, Germination rate of Z. piperitum was much higher in storaging in open ground after treatment of Pon-Pon(80.3%) than in only storaging in open ground(12.4%). In N. domestica. seeds stored for 7 days at $32^{\circ}C$ were germinated faster than those stored for 7 days at $4^{\circ}C$, and germination rate of the former was also higher than that of the latter. Peak Times of seed germination in field were order of E. alatus (32 days). Z. piperitum (49 days). T. sinensis (83 days), N. domestica (87 days). The growth of seedling germinated in field showed a good result because of early germination following the effect of seed treatment. The periods of highest growth performances of the seedlings were 72 days in late Jun.-mid Jul. in E. alatus. 59 days in late Jun.- mid Jul. in Z. Piperitum, and 45 days in mid Aug.- mid Sep. in T. sinensis.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.25-32
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• 2019

Purpose: The size, shape, and volume of prosthetic appliance depend on the metal artifacts resulting from dental implant during head and neck treatment with radiation. This reduced the accuracy of contouring targets and surrounding normal tissues in radiation treatment plan. Therefore, the purpose of this study is to obtain the images of metal representing the size of tooth through MVCT, SMART-MAR CT and KVCT, evaluate the volumes, apply them into the proton therapy plan, and analyze the difference of dose distribution. Materials and Methods : Metal A ($0.5{\times}0.5{\times}0.5cm$), Metal B ($1{\times}1{\times}1cm$), and Metal C ($1{\times}2{\times}1cm$) similar in size to inlay, crown, and bridge taking the treatments used at the dentist's into account were made with Cerrobend ($9.64g/cm^3$). Metal was placed into the In House Head & Neck Phantom and by using CT Simulator (Discovery CT 590RT, GE, USA) the images of KVCT and SMART-MAR were obtained with slice thickness 1.25 mm. The images of MVCT were obtained in the same way with $RADIXACT^{(R)}$ Series (Accuracy $Precision^{(R)}$, USA). The images of metal obtained through MVCT, SMART-MAR CT, and KVCT were compared in both size of axis X, Y, and Z and volume based on the Autocontour Thresholds Raw Values from the computerized treatment planning equipment Pinnacle (Ver 9.10, Philips, Palo Alto, USA). The proton treatment plan (Ray station 5.1, RaySearch, USA) was set by fusing the contour of metal B ($1{\times}1{\times}1cm$) obtained from the above experiment by each CT into KVCT in order to compare the difference of dose distribution. Result: Referencing the actual sizes, it was appeared: Metal A (MVCT: 1.0 times, SMART-MAR CT: 1.84 times, and KVCT: 1.92 times), Metal B (MVCT: 1.02 times, SMART-MAR CT: 1.47 times, and KVCT: 1.82 times), and Metal C (MVCT: 1.0 times, SMART-MAR CT: 1.46 times, and KVCT: 1.66 times). MVCT was measured most similarly to the actual metal volume. As a result of measurement by applying the volume of metal B into proton treatment plan, the dose of $D_{99%}$ volume was measured as: MVCT: 3094 CcGE, SMART-MAR CT: 2902 CcGE, and KVCT: 2880 CcGE, against the reference 3082 CcGE Conclusion: Overall volume and axes X and Z were most identical to the actual sizes in MVCT and axis Y, which is in the superior-Inferior direction, was regular in length without differences in CT. The best dose distribution was shown in MVCT having similar size, shape, and volume of metal when treating head and neck protons. Thus it is thought that it would be very useful if the contour of prosthetic appliance using MVCT is applied into KVCT for proton treatment plan.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.15-21
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• 2005

The purpose of this paper is to experimentally investigate the engine pollutant emissions and combustion characteristics of diesel engine fueled with ethanol-diesel blended fuel (bio-diesohol). The experiments were performed on a single-cylinder DI diesel engine. Two blend fuels were consisted of $15\%$ ethanol, $83.5\%$ diesel and $1.5\%$ solublizer (by volume) were evaluated: one without cetane improver (E15-D) and one with a cetane improver (E15-D+CN improver). The engine performance parameters and emissions including fuel consumption, exhaust temperature, lubricating oil temperature, Bosch smoke number, CO, NOx, and THC were measured, and compared to the baseline diesel fuel. In order to gain insight into the combustion characteristics of bio-diesohol blends, the engine combustion processes for blended fuels and diesel fuel were observed using an Engine Video System (AVL 513). The results showed that the brake specific fuel consumption (BSFC) increased at overall engine operating conditions, but it is worth noting that the brake thermal efficiency (BTE) increased by up to $1-2.3\%$ with two blends when compared to diesel fuel. It is found that the engine fueled with ethanol-diesel blend fuels has higher emissions of THC, lower emissions of CO, NOx, and smoke. And the results also indicated that the cetane improver has positive effects on CO and NOx emissions, but negative effect on THC emission. Based on engine combustion visualization, it is found that ignition delay increased, combustion duration and the luminosity of flame decreased for the diesohol blends. The combustion is improved when the CN improver was added to the blend fuel.