• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1448-1459
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• 2023

A key element of the safety analysis is Loss of Coolant Analysis (LOCA) which must be performed using system thermal-hydraulic codes. These codes are extensively validated against separate effect and integral experiments. RELAP/SCDAPSIM is one such code that may be used to predict LBLOCA response in a CANDU reactor. The RD-14M experiment selected for the Best Estimate Plus Uncertainty study is a 44 mm (22.7%) inlet header break test with no Emergency Coolant Injection. This work has two objectives first is to simulate pipe break with RELAP and compare these results to those available from experiment and from comparable TRACE calculations. The second objective is to quantify uncertainty in the fuel element sheath (FES) temperature arising from model coefficient as well as input parameter uncertainties using Integrated Uncertainty Analysis package. RELAP calculated results are found to be in good agreement with those of TRACE and with those of experiments. The base case maximum FES temperature is 335.5 ℃ while that of 95% confidence 95^th percentile is 407.41 ℃ for the first order Wilk's formula. The experimental measurements fall within the predicted band and the trends and sensitivities are similar to those reported for the TRACE code.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4426-4430
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• 2023

In this article, Exposure Buildup Factor(EBF) and the Energy Absorption Buildup Factor(EABF) have been determined for blood, brain, and muscle using the Monte Carlo method which is represented by MCNP5 codes and compared with geometric progression(G-P) fitting method which is represented by Phy-X/PSD online platform. The novelty of the present work is used an energy source of less than 0.1 MeV to determine buildup factors using MCNP5 and using Phy-X/PSD for some human tissues. thus, the energy range used in this case study was 0.06-3 MeV for penetration depths covered 0.5-3 MFP. Results of MCNP5 and Phy-X/PSD are validated against reference values of water that were reported at ANS-6.4.3. present results of EABFs and EBFs for the previously mentioned human tissues appeared good agreement between MCNP5 in comparison with Phy-X/PSD, whereas, the maximum average relative deviation did not exceed 2.37%. results of our article can be used in different medical applications, such as brachytherapy, radiotherapy, and diagnostics.

• Journal of Preventive Medicine and Public Health
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• 제11권1호
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• pp.110-122
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• 1978

A study on the morbidity of syphilis among 729 workers in Po Hang and Ul San Industiral Complexes at the routine periodical examination was performed. In addition to the morbidity, factors related to the disease infection such as educational level, religion, preventive measures taken by the workers, history of urethritis, and so on were studied and analysed to check significant relation. The results were as follows: 1. VDRL and RPR tests were undertaken to determine the sensitivity and specificity of RPR test which was utilized for all the workers studied. It revealed 86.4% of sensitivity and 87.7% of specificity from RPR test, and 81.8% of sensitivity and 90.1% of specificity from the VDRL test compared with RPCF test. There were 87.4% of agreement rate between RPR and VDRL. Actually, RPR was more sensitive but less specific than VDRL, and found to be a satisfactory screening test for syphilis especially in the fields. 2. Among the workers in Po Hang Area 24.0% of them revealed reactive result, and in Ul San Area 5.2% revealed reactive result showing 4.6 times of risk among workers in Po Hang Area. 3. There were no statistically significant differences between RPR reactive rates and personal characteristics such as educational level, religion, history of urethritis experience, history of coitus with prostitute, and preventive measures of V.D. taken by workers if evaluated by area of Po Hang and Ul Srn separately. 4. V.D. could be encountered as an occupational disease in certain conditions of working places and the psychosocial problems of workers. And so, it is necessary that all the workers working in special estates such as in Po Hang Industrial Complex should be checked to be screened out by RPR test at periodical examinations and part of pre-employment examination also should include RPR test to be compared with. Regardless of the workmen's compensation, establishment of V.D. treatment clinic or system for such industrial workers is urgently needed. Health education regarding V.D. is another subject to be performed.

• Nuclear Engineering and Technology
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• 제12권3호
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• pp.171-179
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• 1980

중성자 및 감마선에 대한 선량율 환산인자(flux-to-dose-rate conversion factors)를 최대흡수선량 개념을 근거로 하여 계산하였다. 중성자 및 감자선에 대한 선량율 군산인자는 에너지 범위가 각각 2.5$\times$$10^{-8}$ 20MeV 및 0.01-15MeV에 대하여 계산하였다. 이제까지 선량율 환산인자는 단일에너지에 대한 값이 였었는데 본 연구에서는 유사인체조직 (phantom)내에서 방사선의 에너지 분포가 직선적이 아니라고 가정하여 계산되었다. 특히 DLC-23, DLC-27, DLC-31 등 핵정수 자료의 각 근에 적합한 선량율 환산인자를 결정하였다는 점이 특색이다. 결과적으로 ANSI N666에 있는 값과 본 연구에서 계산된 값이 잘 일치된다는 것을 확인하였고, 본 결과는 어떤 방사선장에서도 중성자나 감마선 선량율 분포를 계산하는데 이용될 수 있고, 방사선 차폐해석, 방사선방어, radiation dosimetry 등에 필요한 값이 될 것이다.

• 한국중재학회지:중재연구
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• 제28권2호
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• pp.91-110
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• 2018

Consumers repeatedly make small sum purchases through business-to-consumer contracts, usually without incident. Consumer areas have been increasing; therefore, consumer disputes have been occurring frequently as well. In international consumer transactions, it is not easy to solve consumer disputes by applying the laws of different countries. Resolving disputes by using the consumer arbitration system can be a measure to protect consumers. In the U.S., a class arbitration is being operated as a mixed dispute resolution system of class action and arbitration. Consumer Arbitration has long been a controversial issue in the U.S. It is therefore a lesson for us to examine related cases. A recent U.S. Supreme Court decision, DIRECTV v. Imburgia, was looked into and after a summary of the facts, issues, and opinions and opposing opinions that had a tight controversy, a close analysis was done. The analysis through this judgment is as follows: first, the contraction of consumer protection; second, the expansion of the Federal Arbitration Act scope; third, the class arbitration's restriction; and fourth, the submission of the arbitration fairness act.

• 한국정보통신학회논문지
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• 제13권7호
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• pp.1261-1266
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• 2009

본 논문에서는 이동통신용 단말기 PCB Layout 위에 내장형 칩 안테나를 직접 설계하여 DCS(1.71${\sim}$1.88GHz) 대역, PCS(1.75${\sim}$1.87GHz) 대역 및 UPCS(1.85${\sim}$1.99GHz)대역에서 공통으로 사용할 수 있는 이동통신용 트리플밴드 칩 안테나를 설계하였다. 안테나의 특성 해석을 위해서 상용 고주파 시뮬레이션인 HFSS를 이용하였다. 트리플 광대역 특성은 1.71GHz${\sim}$1.99GHz의 대역에서 동작하는 설계된 안테나의 측정된 대역폭(V.S.W.R<2.0)을 실현시켰다. 이 안테나의 크기는 19mm${\times}$4mm${\times}$1.6mm로 설계하여 소형화시켰으며, 칩 안테나의 단점인 좁은 대역폭을 크게 개선시켰다. 그리고 실험 측정 결과들은 시뮬레이션 결과들과 매우 유사함을 보여 주었다.

• Korean Journal of Radiology
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• 제25권7호
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• pp.634-643
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• 2024

Objective: This study aimed to evaluate the diagnostic efficacy and safety of low-contrast-dose, dual-source dual-energy CT before transcatheter aortic valve replacement (TAVR) in patients with compromised renal function. Materials and Methods: A total of 54 consecutive patients (female:male, 26:38; 81.9 ± 7.3 years) with reduced renal function underwent pre-TAVR dual-energy CT with a 30-mL contrast agent between June 2022 and March 2023. Monochromatic (40- and 50-keV) and conventional (120-kVp) images were reconstructed and analyzed. The subjective quality score, vascular attenuation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were compared among the imaging techniques using the Friedman test and post-hoc analysis. Interobserver reliability for aortic annular measurement was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. The procedural outcomes and incidence of post-contrast acute kidney injury (AKI) were assessed. Results: Monochromatic images achieved diagnostic quality in all patients. The 50-keV images achieved superior vascular attenuation and CNR (P < 0.001 in all) while maintaining a similar SNR compared to conventional CT. For aortic annular measurement, the 50-keV images showed higher interobserver reliability compared to conventional CT: ICC, 0.98 vs. 0.90 for area and 0.97 vs. 0.95 for perimeter; 95% limits of agreement width, 0.63 cm² vs. 0.92 cm² for area and 5.78 mm vs. 8.50 mm for perimeter. The size of the implanted device matched CT-measured values in all patients, achieving a procedural success rate of 92.6%. No patient experienced a serum creatinine increase of ≥ 1.5 times baseline in the 48-72 hours following CT. However, one patient had a procedural delay due to gradual renal function deterioration. Conclusion: Low-contrast-dose imaging with 50-keV reconstruction enables precise pre-TAVR evaluation with improved image quality and minimal risk of post-contrast AKI. This approach may be an effective and safe option for pre-TAVR evaluation in patients with compromised renal function.

• Journal of Astronomy and Space Sciences
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• 제23권1호
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• pp.1-10
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• 2006

We report the photometric properties in BVR bands for the resolved bright supergiant stars in the dwarf galaxy Holmberg II. The color-magnitude diagrams and color-color diagram of 374 resolved stars indicate that the majority of the member stars are supergiant stars with a wide range of spectral type between B-K. A comparison with theoretical evolutionary tracks indicates that the supergiant stars in the observed field have progenitor masses between ${\sim}10M_{\bigodot}\;and\;20M_{\bigodot}$. The exponent of luminosity function in V is in good agreement with those of the Small and Large Magellanic Clouds.

• 전기의세계
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• 제28권4호
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• pp.53-63
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• 1979

Interface recombination velocity in $Al_{x}$G $a_{1-x}$ As-GaAs and $Al_{0.85}$, G $a_{0.15}$ As-GaA $s_{1-y}$S $b_{y}$ heterojunction systems is studied as a function of lattice mismatch. The results are applied to the design of highly efficient III-V heterojunction solar cells. A horizontal liquid-phase epitaxial growth system was used to prepare p-p-p and p-p-n $Al_{x}$G $a_{1-x}$ As-GaA $s_{1-y}$S $b_{y}$-A $l_{x}$G $a_{1-x}$ As double heterojunction test samples with specified values of x and y. Samples were grown at each composition, with different GaAs and GaAs Sb layer thicknesses. A method was developed to obtain the lattice mismatch and lattice constants in mixed single crystals grown on (100) and (111)B oriented GaAs substrates. In the AlGaAs system, elastic lattice deformation with effective Poisson ratios .mu.$_{eff}$ (100=0.312 and .mu.$_{eff}$ (111B) =0.190 was observed. The lattice constant $a_{0}$ (A $l_{x}$G $a_{1-x}$ As)=5.6532+0.0084x.angs. was obtained at 300K which is in good Agreement with Vegard's law. In the GaAsSb system, although elastic lattice deformation was observed in (111) B-oriented crystals, misfit dislocations reduced the Poisson ratio to zero in (100)-oriented samples. When $a_{0}$ (GaSb)=6.0959 .angs. was assumed at 300K, both (100) and (111)B oriented GaAsSb layers deviated only slightly from Vegard's law. Both (100) and (111)B zero-mismatch $Al_{0.85}$ G $a_{0.15}$As-GaA $s_{1-y}$S $b_{y}$ layers were grown from melts with a weight ratio of $W_{sb}$ / $W_{Ga}$ =0.13 and a growth temperature of 840 to 820 .deg.C. The corresponding Sb compositions were y=0.015 and 0.024 on (100) and (111)B orientations, respectively. This occurs because of a fortuitous in the Sb distribution coefficient with orientation. Interface recombination velocity was estimated from the dependence of the effective minority carrier lifetime on double-heterojunction spacing, using either optical phase-shift or electroluminescence timedecay techniques. The recombination velocity at a (100) interface was reduced from (2 to 3)*10$^{4}$ for y=0 to (6 to 7)*10$^{3}$ cm/sec for lattice-matched $Al_{0.85}$G $a_{0.15}$As-GaA $s_{0.985}$S $b_{0.015}$ Although this reduction is slightly less than that expected from the exponential relationship between interface recombination velocity and lattice mismatch as found in the AlGaAs-GaAs system, solar cells constructed from such a combination of materials should have an excellent spectral response to photons with energies over the full range from 1.4 to 2.6 eV. Similar measurements on a (111) B oriented lattice-matched heterojunction produced some-what larger interface recombination velocities.ities.ities.s.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.225-232
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• 2009

An analytical compact model for the asymmetric lightly doped Double Gate (DG) MOSFET is presented. The model is developed using the Lambert Function and a 2-dimensional (2-D) parabolic electrostatic potential approximation. Compact models of the net charge and channel current of the DG-MOSFET are derived in section 2. Results for the channel potential and current are compared with 2-D numerical data for a lightly doped DG MOSFET in section 3, showing very good agreement.