• Computational Structural Engineering
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• v.4 no.4
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• pp.79-89
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• 1991

New design method of R/C slab system based on finite element method has been presented. The proposed method can substitute inaccurate existing method, which has limitation in its application, and provide accurate and efficient design results for any type of slab system. Isoparametric plate element used in the slab design has been efficiently formulated to save computational time. Reinforcement has been determined by strength design method and compared with code minimum values. Graphical output through comprehensive contour map for resulting moments and designed steel areas has considerably facilitated design process. Accurate shear results from isoparametric plate element enabled to check punching shear in a proper manner. In addition to strength design criteria, serviceability has also been checked by utilizing newly developed inelastic deflection multiplier method. An example for circular slab with opening showed that the proposed method could be applied to design of irregular slab without any difficulty.

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.145-152
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• 2017

The powdery mildew on Castanea crenata in South Korea was first recorded as Microsphaera alni in 1958. On the basis of its morphological characteristics and host range, the mildew was determined as Microsphaera sinensis in 1988. According to the rules of The International Code of Botanical Nomenclature, M. sinensis was renamed Erysiphe castaneigena in 2006. Nevertheless, taxonomic re-consideration of the morphological and molecular characteristics for the Castanea powdery mildew in Korea has not been performed. In the present study, we studied 34 powdery mildew samples collected from C. crenata in the Korea University Herbarium. On the basis of microscopic examinations of the holomorph and phylogenetic analysis of the internal transcribed spacer regions, we confirmed the powdery mildew fungus as E. castaneigena. In addition, sequence comparison between E. castaneigena and E. alphitoides ex Castanea sp. suggested a close phylogenetic affinity.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.27.1-27.1
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• 2011

We obtained the spectra of 93 Planet host stars and 73 normal field stars in F, G, K type using BOES at BOAO. We measured the equivalent width of Fe and 25 elements lines using the automatic EW measurement program, TAME(Tools for Automatic Measurement of Equivalent-widths) and estimated the elemental abundances by synth and abfind driver of MOOG code. Since the absence of planets in the normal field stars cannot be "completely" proved, this work focused on the chemical abundances and planet properties of planet host stars, which have the massive planets close to the parent star relatively. We carried out an investigation for the difference of abundances between stars with "Hot Jupiter" and normal field stars with no known planets. We examined the chemical composition of 25 elements, such as C, N, O, S, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu by EW measurements, and the S abundances were estimated using synthetic spectrum. We have found that [Mg/Fe] and [Al/Fe] for planet host stars have lower limit comparing with those of comparison stars, and [Ca/Fe] of host star with Neptunian planets is relatively lower than the other host stars with massive planets. We have performed the Kolmogorov-Smirnov test, and examined the ratio of planet host stars to all stars for each bin of [X/H]. As a result, we noted that the O, Si, and Ca abfor undances are strongly related with the presence of planets.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.695-705
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• 2014

Precast concrete (PC) beam-column connections using ductile rods are proposed for earthquake zone. An existing beam-column connection, two PC specimens designed by considering failure modes and a conventional RC specimen were tested under cyclic loading to evaluate the seismic performance. The specimens were designed to satisfy the requirements of current design code. The variables are the yield strength of longitudinal reinforcing bars of PC beams. The test results showed that the proposed system applying smaller yield strength of the longitudinal reinforcing bars at the PC beams than the ductile rods was satisfied with seismic criteria. The deformation capacity and energy dissipation capacity of the proposed PC beam-column connections were greater than those of the existing DDC system.

• The KSFM Journal of Fluid Machinery
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• v.18 no.2
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• pp.60-66
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• 2015

Conjugate heat transfer analysis was performed to investigate the flow and cooling performance of the high pressure turbine nozzle of gas turbine engine. The CHT code was verified by comparison between CFD results and experimental results of C3X vane. The combination of k-${\omega}$ based SST turbulence model and transition model was used to solve the flow and thermal field of the fluid zone and the material property of CMSX-4 was applied to the solid zone. The turbine nozzle has two internal cooling channels and each channel has a complex cooling configurations, such as the film cooling, jet impingement, pedestal and rib turbulator. The parabolic temperature profile was given to the inlet condition of the nozzle to simulate the combustor exit condition. The flow characteristics were analyzed by comparing with uncooled nozzle vane. The Mach number around the vane increased due to the increase of coolant mass flow flowed in the main flow passage. The maximum cooling effectiveness (91 %) at the vane surface is located in the middle of pressure side which is effected by the film cooling and the rib turbulrator. The region of the minimum cooling effectiveness (44.8 %) was positioned at the leading edge. And the results show that the TBC layer increases the average cooling effectiveness up to 18 %.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1395-1401
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• 2004

In The objective of this paper is to apply blind minimum output energy multiuser detection method to multicarrier direct sequence code division multiple access system. The performance of MC/DS-CDMA is reduced due to multiple access. To increase the performance of system, we need to cancel multiple user components. Blind interference canceller is able to detect the desired's information with the only minimal information of the desired user. We evaluate the performance of the proposed receiver under Gaussian channel. Simulation results show that the proposed receiver has about 6［dB］ gain of signal to noise ratio without multiple user interference and has about 3［dB］ gain of SNR with multiple user interference. Also, the result of comparing the capacity of the active users shows that the proposed method has about 2 times capacity more than conventional method. As a conclusion, simulation results show that the proposed method has better performs better than conventional method.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.29-35
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• 2013

In this paper, we investigate the type and detection methode of spoofing attack, and then analyze the performance of spoofing detection algorithm in GPS L1 signal through the simulation. Generally spoofer is different from the jammer, because the receiver can be operated and not. In case of spoofing the GPS receiver is hard to recognize the spoofing attack and can be operated normally without stopping because the spoofing signal is the mimic GPS signal. To evaluate the performance of spoofing detection algorithm, both the software based spoofing and GPS signal generator and the software based GPS receiver are implemented. In paper, we can check that spoofing signal can affect to the DLL and PLL tracking loop because code delay and doppler frequency of spoofing. The spoofing detection algorithm has been implemented using the pseudorange, signal strength and navigation solution of GPS receiver and proposed algorithm can effectively detect the spoofing signal.

• Korean Journal of Clinical Pharmacy
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• v.31 no.2
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• pp.153-159
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• 2021

Background: With increasing economic evaluation studies on the treatment of or screening tools for liver diseases that cause hepatocellular carcinoma (HCC), interest in the analysis of the medical utilization and costs of HCC treatment is increasing. Therefore, we aimed to estimate the medical utilization and costs of HCC patients, and calculate the cost of main procedures for HCC treatment, including liver transplant (LT), hepatic resection (HR), radiofrequency ablation (RFA), and transarterial chemoembolization (TACE). Methods: We analyzed claim data from January to December 2018 from the Health Insurance and Review and Assessment Service-National Patient Sample (HIRA-NPS-2018) dataset, including data of patients diagnosed with HCC (Korean Standard Classification of Diseases code C22.0) who had at least one inpatient claim for HCC. Results: A total of 715 HCC patients were identified. In 2018, the yearly average medical cost per HCC patient was ₩18,460K (thousand), of which ₩14,870K was attributed to HCC. Among the total medical costs of HCC patients, the inpatient cost accounted for the largest portion of both the total medical and HCC-related costs. The major procedures of HCC treatment occurred most frequently in the order of TACE, RFA, HR, and LT. The average medical cost per treatment episode was the highest for LT (₩87,280K), followed by HR (₩10,026K), TACE (₩4,047K), and RFA (₩2,927K). Conclusion: By identifying the medical costs of HCC patients and the costs of the main procedures of HCC treatment, our results provide basic information that could be utilized for cost estimation in liver disease-related economic evaluation studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.107-114
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• 2020

Technologies related scan-to-BIM for BIM-based reverse engineering techniques are beginning to be actively introduced in the A.E.C. industry, and the scalability of the technology is growing considerably. This study uses patent analysis based on objective data to find the right direction for Korean Scan-to-BIM technology by identifying the trends in Korea, the United States, Europe, and Japan. This was done using the WIPSON patent search system to find previous research on patent analysis related to building technology, theoretical consideration of scan-to-BIM technology, and published patents. We collected information, verified the process, and extracted valid patents. We used the effective patent data to analyze the annual trend of patent applications, national trends, and technological trends through the International Patent Classification (IPC) code, the types of the top 20 major applicants, and family patent trends.

• Journal of Radiation Protection and Research
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• v.46 no.2
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• pp.58-65
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• 2021

Background: The evaluation of skyshine distribution, release of airborne radioactive nuclides, and soil activation and groundwater migration were required for radiological assessment of the impact on the environment surrounding In-Flight (IF)-system facility of the RAON (Rare isotope Accelerator complex for ON-line experiment) accelerator complex. Materials and Methods: Monte Carlo simulation by MCNPX code was used for evaluation of skyshine and activation analysis for air and soil. The concentration model was applied in the estimation of the groundwater migration of radionuclides in soil. Results and Discussion: The skyshine dose rates at 1 km from the facility were evaluated as 1.62 × 10^-3 μSv·hr^-1. The annual releases of ³H and ¹⁴C were calculated as 9.62 × 10^-5 mg and 1.19 × 10^-1 mg, respectively. The concentrations of ³H and ²²Na in drinking water were estimated as 1.22 × 10^-1 Bq·cm^-3 and 8.25 × 10^-3 Bq·cm^-3, respectively. Conclusion: Radiological assessment of environmental impact on the IF-facility of RAON was performed through evaluation of skyshine dose distribution, evaluation of annual emission of long-lived radionuclides in the air and estimation of soil activation and groundwater migration of radionuclides. As a result, much lower exposure than the limit value for the public, 1 mSv·yr^-1, is expected during operation of the IF-facility.