• The Journal of Korean Society for Radiation Therapy
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• v.22 no.1
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• pp.25-32
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• 2010

Purpose: In radiotherapy that takes into account respiration using a RPM (Real time Position Management, Varian, USA) system, which can treat in consideration of the movement of tumor, infrared reflective markers supplied by manufacturers cannot obtain respiratory signal if the couch rotates at a certain angle or larger. In order to solve this problem, the author developed the 3D infrared reflective marker named 'Kw-marker' that can obtain respiratory signal at any angle, and evaluate its usefulness. Materials and Methods: In order to measure the stability of respiratory signal, we put the infrared reflective marker on the 3D moving phantom that can reproduce respiratory movement and acquired respiratory signal for 3 minutes under each of 3 conditions (A: $couch\;0^{\circ}$, a manufacturer's infrared reflective marker B: $couch\;0^{\circ}$, Kw-marker C: $couch\;90^{\circ}$, Kw-marker). By analyzing the respiratory signal using a breath analysis program (Labview Ver. 7.0), we obtained the peak value, valley value, standard deviation, variation value, and amplitude value. In order to examine the rotation error and moving range of the target, we placed a B.B phantom on the 3D moving phantom, and obtained images at a couch angle of $0^{\circ}$ and $90^{\circ}$ using OBI, and then acquired the X, Y and Z values (mm) of the ball bearing at the center of the B.B phantom. Results: According to the results of analyzing the respiratory signal, the standard deviation at the peak value was A: 0.002, B: 0.002 and C: 0.003, and the stability of respiration for amplitude was A: 0.15%, B: 0.14% and C:0.13%, showing that we could get respiratory signal stably by using the Kw-marker. When the couch rotated $couch\;90^{\circ}$, the mean rotation error of the ball bearing, namely, the target was X: -1.25 mm, Y: -0.45 mm and Z: +0.1 mm, which were within 1.3 mm on the average in all directions, and the difference in the moving range of the target was within 0.3 mm. Conclusion: When we obtained respiratory signal using the Kw-marker in non-coplanar treatment where the couch rotated, we could acquire respiratory signal stably and the Kw-marker was effective enough to substitute for the manufacturer's infrared reflective marker. When the rotation error and moving range of the target were measured, there was little difference, indicating that the displacement of the reflector movement in couch rotation is the cause of change in the scale and amplitude of respiratory signal. If the converted value of amplitude height according to couch angle is studied further and applied, it may be possible to perform non-coplanar phase-based gating treatment.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.488-492
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• 2007

In this study, we investigated how to distinguish customer delivered value to re-purchasing in fierce B2C industry. To identify key managerial variables that could distinctively impact re-purchasing, we first identified customer value proposition as per the customer buying decision process. Next, core value propositions of choice efficiency and competitive price are defined to determine vendor satisfaction during the searching stage and purchasing stage. The trust level is also introduced in the sense of reflecting confirmation to guarantee after purchase security. Then, significant managerial variables to impact on core value propositions are extracted. The resulting structural model illustrated that search convenience and quality assurance affect the choice efficiency, and re-purchase intention is strongly explained by both the vendor satisfaction and trust level. The empirical testing results also support that transaction cost reduction is key determinant of shopping at the Internet shopping mall. Furthermore, trust level should be combined to induce re-purchasing in addition to transaction cost savings.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1049-1061
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• 2022

Neutron and gamma-ray shielding properties of Inconel 718 reinforced B₄C (0-25 wt%) were investigated using PSD software. Mean free path (MFP), linear and mass attenuation coefficients (LAC,MAC), tenth-value and half-value layers (TVL,HVL), effective atomic number (Z_eff), exposure buildup factors (EBF), and fast neutron removal cross-sections (FNRC) values were calculated for 0.015-15 MeV. It was found that MAC and LAC increased with the decrease in the content of B₄C compound by weight in Inconel 718. The EBFs were computed using G-P fitting method for 0.015-15 MeV up to the penetration depth of 40 mfp. HVL, TVL, and FNRC values were found to range between 0.018 cm and 3.6 cm, between 2.46 cm and 12.087 cm, and between 0.159 cm^-1 and 0.194 cm^-1, respectively. While Inconel 718 provides the maximum photon shielding property since it offered the highest values of MAC and Z_eff and the lowest value of HVL, Inconel 718 with B₄C(25 wt%) was observed to provide the best shielding material for neutron since it offered the highest FNRC value. The study is original in terms of several aspects; moreover, the results of the study may be used in nuclear technology, as well as other technologies including nano and space technologies.

• Journal of the Korean Society of Radiology
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• v.5 no.2
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• pp.59-66
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• 2011

There is a difficulty because of classifying the anatomical structure in the neck CT scan by the beam hardening artifact no more than disease and it including the 6, 7 number cervical spine and intervertebral disk. In case of enforcing the neck CT scan cause of the inner diameter of beam artifact tried to be inquired by the image evaluation according to the change of the image evaluation according to the direction of the shoulder joint applying the variation method of a posture and location and Kernel value and it was most appropriate, the lion tax and Kernel value try to be searched for through an experiment. Somatom Sensation 16 (Siemens, Enlarge, Germany) equipment was used in a patient 30 people coming to the hospital for the neck CT scan. A workstation used the AW 4.4 version (GE, USA). According to a direction and location of the shoulder joint, the patient posture gave a change to the direction of the shoulder joint as the group S it gave a change as three postures and placed the both arms comfortably and helps a group N and augmented unipolar left in the wealthy merchant and group P it memorized the both hands and ordered the eversion and drops below to the utmost and enforced a scan. By using a reconstructing method as the second opinion, it gave and reconstructed the Kernel value a change based on scan data with B 10 (very smooth), B 20 (smooth), B 30 (medium smooth), B 40 (medium), B 50 (medium sharp), B 60 (sharp), and B 70 (very sharp). By using image data which gave the change of the examination posture and change of the Kernel value and are obtained, we analyzed through the noise value measurement and image evaluation of. The outside wire eversion orders the both hands and the examination posture is cost in the neck CT scan with the group P it drops below to the utmost. And in case of when reconstructing with B 40 (medium) or B 50 (medium sharp) being most analyzed into the inappropriate posture and Kernel value and applying the Kernel value to a clinical, it is considered to be very useful.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.396-405
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• 2019

The speech privacy of closed office rooms located in a university campus was measured and assessed in terms of SPC (Speech Privacy Class) values. The measurements of two quantities, the LD (Level Difference) between a source and a receiving room, and the background noise level ($L_b$) at the receiving room were carried out in 5 rooms located in 3 different buildings in the university campus. Each of the 5 rooms was adjacent to both offices and corridors through walls. The TL (Transmission Loss) between the source and the receiver room was also measured to compare the difference of two standard methods, ASTM E2836-10 and KS F 2809. The present results show that the speech privacy of the 5 office rooms is not met the requirement for a minimum SPC values of 70. A minimum LD value of 41 dB between the source and the receiver room should be achieved for having a SPC value of 70 when the mean measured value of $L_b$ at the receiving room is 29.2 dB. That is, the TL(avg) value averaged over the octave bands from 160 Hz to 5000 Hz between the source and the receiver room should be or greater than 40 dB. The most important architectural factor influencing the LD value is the presence of openings, such as doors, and windows, on the adjacent walls between the source and receiving room. Therefore, if the opening of the adjacent wall is replaced by an opening with high sound insulation, the appropriate SPC value of the research and office rooms can be achieved.

• The Korean Journal of Food And Nutrition
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• v.22 no.3
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• pp.402-408
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• 2009

The study assessed the quality characteristics of Sulgiddeok with self-made and commercially-available rice flours during a 1-day storage at ambient temperature($20\sim22^{\circ}C$). The nutritional components, color value, physical tests, internal structure as revealed by scanning electron microscopy SEM, and sensory evaluation of Sulgiddeok were determined. Sulgiddeok prepared with self-made rice flour and two commercial rice flour were designated as sample A, B, and C, respectively. Moisture content, crude protein, crude lipid, and pH did not differ significantly among the preparations. Sweetness was highest in sample B(p<0.01) and crude ash was highest in sample A(p<0.001). L color, a value, and b value was highest in sample B, C, and C, respectively. Texture property analysis showed that hardness, gumminess, and chewiness tended to decrease during the 1-day storage, while adhesiveness, springiness, and cohesiveness tended to increase. Sensory characteristics of color, flavor, chewiness, gumminess, externals, and overall quality of sample A were superior to samples B and C. However, softness was highest in sample B. The internal structure of Sulgiddeok was preserved in sample A. It is concluded that rice flour B can make Sulgiddeok comparable to that prepared using self-made rice flour.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.2
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• pp.35-41
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• 2009

The impacts of climate change on paddy irrigation requirements for Nakdong river basin in Korea have been analyzed. The HadCM3 model outputs for SRES A2 and B2 scenarios and International Water Management Institute $10'{\times}10'$ pixels observed data were used with kriging method. Maps showing the predicted spatial variations of changes in climate parameters and paddy irrigation requirements have been produced using the GIS. The results showed that the average growing season temperature was projected to increase by $2.2^{\circ}C$ (2050s A2), $0.0^{\circ}C$ (2050s B2), $3.7^{\circ}C$ (2080s A2) and $2.9^{\circ}C$ (2080s B2) from the baseline (1961-1990) value of $21{\circ}C$. The average growing season rainfall was projected to increase by 15.2% (2050s A2), 24.2% (2050s B2), 41.4% (2080s A2) and 16.7% (2080s B2) from the baseline value of 900 mm. Average volumetric irrigation demands were projected to decrease by 3.7% (2050s A2), 7.0% (2050s B2), 10.2% (2080s A2) and 1.4% (2080s B2) from the baseline value of $1.25{\times}10^9\;m^3$. These results can be used for the agricultural water resources development planning in the Nakdong river basin for the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.263-267
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• 2002

This experiment was conducted to find out the varietal differences in the relationships of chlorophyll and nitrogen concentration with leaf greenness value (SPAD value). We used two rice varieties with different leaf color type: Hwaseongbyeo has pale green leaves, and Gwanganbyeo has dark green leaves. SPAD value was correlated with chlorophyll a concentration significantly in both varieties, but not with chlorophyll b in Hwaseongbyeo. The correlation coefficients between SPAD value and nitrogen concentration of rice flag leaves were highly significant. However, the regression analysis between SPAD value and nitrogen concentration of rice flag leaves showed different relation among varieties. The slope of the regression line in Gwanganbyeo was steeper than that in Hwaseongbyeo. In conclusion, SPAD value can be applied to estimate the chlorophyll a concentration without consideration of varietal differences. Chlorophyll b and nitrogen concentration in the leaf were regressed to the SPAD values differently with varieties. This implies that the SPAD value can not be used directly to estimate chlorophyll b and nitrogen concentration without consideration of varietal differences.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.165-170
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• 2023

Isolation of the culture broth of a marine-derived Acremonium sp. CNQ-049 guided by HPLC-UV yielded compound 1 (3-phenethyl-2-phenylquinazolin-4(3H)-one), and its inhibitory activities against monoamine oxidases (MAOs), cholinesterases (ChEs), and β-secretase 1 (BACE1) were evaluated. Compound 1 was an effective selective MAO-B inhibitor with an IC₅₀ value of 9.39 µM and a selectivity index (SI) value of 4.26 versus MAO-A. In addition, compound 1 showed a potent selective butyrylcholinesterase (BChE) inhibition with an IC₅₀ value of 7.99 µM and an SI value of 5.01 versus acetylcholinesterase (AChE). However, compound 1 showed weak inhibitions against MAO-A, AChE, and BACE1. The Ki value of compound 1 for MAO-B was 5.22±1.73 µM with competitive inhibition, and the Ki value of compound 1 for BChE was 3.00±1.81 µM with mixed-type inhibition. Inhibitions of MAO-B and BChE by compound 1 were recovered by dialysis experiments. These results suggest that compound 1 is a dual-functional reversible inhibitor of MAO-B and BChE, that can be used as a treatment agent for neurological disorders.

• The Korean Journal of Nuclear Medicine
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• v.3 no.1
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• pp.19-32
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• 1969

Radioisotope renography was carried out in 564 cases consisting of 150 normal controls, 140 hypertensives, 102 hypertensive nephropathys, 62 chronic renal diseases, non-functioning kidneys. It was aimed to study which parameter of the renogram is most applicable to any definite disease of the kidney. The analytical methods adopted were; Tobe, Spencer, Krueger, Matchida and Takeuchi. In the non-functioning kidney groups, the hemograms and serum nitrogen series were also studied to evaluate the relationships between the renograms and renal anemia. The parameters were; time of maximum amplitude (Tmax), half-time of maximum amplitude ($T\frac{1}{2}$), Kac value calculated from these two parameters in Tobe's method, slopes of Band C phase, B/A and B/C values in Spencer's method, total concentration (T.C.), minute concentration (M.C.) and minute excretion (M.E.) in Krueger's method, Matchida's K value and Takeuchi's renal function Index (R.F.I.). Following were the results: 1. In general, marked differences in the patterns of the renogram were observed between the normal controls and nephropathys. In Tobe's method, each parameter showed statistically significant delay or decrease in patients with hypertensive nephropathys and chronic renal diseases. In Spencer's method, slopes of B and C phase and B/C, also showed the statistically significant decrease in patients with hypertension, hypertensive nephropathys and chronic renal diseases. In Krueger's method, M.C. and ME showed the statistically significant differences between the control and patients with hypertension, hypertensive nephropathys and chronic renal diseases, In Matchida's method, K value showed the statistically significant differences between the control and patients with hypertensive nephropathys and chronic renal diseases. 2. It appeared, therefore, that Tobe's $T\frac{1}{2}$, Kac value, Spencer's slopes of Band C phase, B/A, B/C values, Krueger's T.C., M.C., and M.E. values, Matchida's K value are useful for the differentiation of various renal diseases, however, qualitative analysis of the renogram with one or two parameters is not accurate. 3. In bilateral non-functioning kidney groups, a positive correlation between anemia and nitrogen retention was observed, although the quantitative assessment of the degree of non-functioning was impossible.