• Wind and Structures
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• 제13권6호
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• pp.487-498
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• 2010

When designing structures to the wind action, the variation of the mean wind velocity and turbulence parameters with the height above the ground must be taken into account. This paper presents the numerical simulation results of atmospheric boundary layer (ABL) airflows, in a numerical domain with no obstacles and with a cubic building. The results of the flow characterization, obtained with the FLUENT CFD code were performed using the ${\kappa}-{\varepsilon}$ turbulence model with the MMK modification. The mean velocity and turbulence intensity profiles in the inflow boundary were defined in accordance with the Eurocode 1.4, for different conditions of aerodynamic roughness. The maintenance of the velocity and turbulence characteristics along the domain were evaluated in an empty domain for uniform incident flow and the ABL Eurocode velocity profiles. The pressure coefficients on a cubic building were calculated using these inflow conditions.

• 설비공학논문집
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• 제1권3호
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• pp.252-263
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• 1989

A system of conservation equations for steady, oscillatory and pulsating duct flows are solved analytically by linearizing non-linear convective terms. Analytical solutions of velocity profiles for these flows are obtained in the form of infinite series. The experimental study for the air flow in a square duct ($40mm{\times}40mm$ and 400 mm long) is carried out to measure velocity profiles and other parameters by using a hot-wire anemometer with data acquisition and processing system. Major characteristics of the flows such as the classification of flow patterns, determination of critical Reynolds number and velocity profiles is accomplished from the experismental results.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2013년도 춘계학술대회
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• pp.275-276
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• 2013

This analysis method is based on the wave pressure function with the continuity in the analytical region including fluid and porous structures. Wave profiles coming with oblique angle to permeable submerged breakwater on the porous seabed are computed numerically by using boundary element method. When compared with the existing results for the oblique incident wave, the results of this study show good agreement. The results indicate that wave profiles own high dependability regarding the change of oblique incident waves and permeable submerged breakwater on the porous seabed. Therefore, the analysis method of this study are estimated to be applied as an accurate numerical analysis referring to oblique incident waves and permeable submerged breakwater on the porous seabed in real sea environment.

• Transactions on Electrical and Electronic Materials
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• 제14권2호
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• pp.94-100
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• 2013

The elements B, P and As can each be implanted in silicon; for the fabrication of integrated semiconductor devices and the wells in CMOS (complementary metal oxide semiconductor). The implanted range due to different implanted species calculated using TRIM (Transport of Ions in Matter) simulation results was considered. The profiles of implanted samples could be measured using SIMS (secondary ion mass spectrometry). In the comparison between the measured and simulated data, some deviations were shown in the profiles of MeV implanted silicon. The Moliere, C-Kr, and ZBL potentials were used for the range calculations, and the results showed almost no change in the MeV energy region. However, the calculations showed remarkably improved results through the modification of the electronic stopping power. The results also matched very well with SIMS data. The calculated tolerances of $R_p$ and ${\Delta}R_p$ between the modified $S_e$ of TRIM and SIMS data were remarkably better than the tolerances between the TRIM and SIMS data.

• 한국식물병리학회지
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• 제14권2호
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• pp.171-176
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• 1998

Gentic diversity of 42 isolates of Phomopsis citri was analyzed with random amplified polymorphic DNA(RAPD) and fungicide resistance. RAPD profiles of genomic DNA of the isolates of P. citri and the degrees of their resistance to the fungicides mancozeb and propineb suggested the occurrence of genetic differentiation of P. citri distributed in Cheju. The isolates showed genetically diverse RAPD profiles according to the host species collected even from the same collection site and also according to the geographic origin collected even from the same host species. High levels of resistance to fungicides mancozeb and propineb were observed among the isolates of P. citri. However, there was no correlation between RAPD profiles of genomic DNA and levels of fungicide resistance of the isolates, suggesting that fungicide resistance of P. citri occurred irrespective of the host and geographic origin.

• 한국진공학회지
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• 제14권4호
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• pp.245-251
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• 2005

A high performance dual rocking magnet sputtering gun has been developed. The rocking magnet sputtering gun introduces full-face erosion by rapidly rocking the magnet in the region where the high plasma density is maintained. The newly developed dual rocking magnet sputtering gun whose target utilization was 77 percent achieved high performance in quality in the view of target utilization and target life-time comparing to the existing magnetron sputtering gun. The PIC-MCC target erosion simulation has been performed simultaneously. Comparing experimental target erosion profiles with simulated target erosion profiles, the simulation could estimate the tendency of the target erosion profiles but could not estimate an exact target erosion profile. If the simulation were improved more precisely, the cost reduction for the development of the multiple rocking magnet sputtering gun would be expected.

• 대한기계학회논문집A
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• 제28권5호
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• pp.511-516
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• 2004

The dynamic behavior of an automatic ball balancer (ABB) is studied considering the effects of gravity and angular velocity profiles. In this study, a physical model for an ABB installed on the Jeffcott rotor is adopted in order to investigate the effects of gravity and angular acceleration. The equations of motion for the rotor with ABB are derived by using Lagrange's equation. Based on derived equations, dynamic responses for the rotor are computed by using the generalized-o method. From the computed responses, the effects of gravity and angular velocity profiles on the dynamic behavior are investigated. It is found that the balancing of the rotor with ABB can be achieved regardless of gravity. It Is also shown that a smooth velocity profile yields relatively smaller vibration amplitude than a non-smooth velocity profile.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 봄 학술발표논문집 Vol.31 No.1 (B)
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• pp.7-9
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• 2004

With the development of e-commerce and information access, recommender systems have become a popular technique to prune large information spaces so that users are directed toward those items that best meet their needs and preferences. In this paper, clustering technique is applied in the collaborative recommender framework to consider semantic contents available from the user profiles. We also suggest methods to construct user profiles from rating information and attributes of items to accommodate user preferences. Further, we show that the correct application of the semantic content information obtained from user profiles does enhance the effectiveness of collaborative recommendation.

• 천문학회지
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• 제35권3호
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• pp.123-130
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• 2002

An elliptical accretion disk may be formed by tidally disrupted debris of a flying-by star in an active galactic nucleus (AGN) or by tidal perturbation due to a companion in a binary black hole system. We investigate the iron K$\alpha$ line profiles expecting from a geometrically thin, relativistic, elliptical disk in terms of model parameters, and find that a broad and skewed line profile can be reproduced well. Its shape is variable to the model parameters, such as, the emissivity power-law index, the ellipticity of the disk, and the major axis orientation of the elliptical accretion disk. We suggest that our results may be useful to search for such an elliptical disk and consequently the tidal disruption event.

• Bulletin of the Korean Chemical Society
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• 제18권7호
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• pp.695-702
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• 1997

The objective of this work is to determine the sugar profiles in commercial fruit juices, and to obtain chemometric characteristics. Sugar compositions of fruit juices were determined by HPLC-RID and GC-FID via methoxymation and trimethylsilylation with BSTFA. The appearance of multiple peaks in GC analysis for carbohydrates was disadvantageous as described in earlier literatures. Fructose, glucose, and sucrose were major carbohydrates in most fruit juices. Glucose/fructose ratios obtained by GC were lower than those by HPLC. Orange juices are similar to pineapple juices in the sugar profiles. However, grape juices are characterized by its lower or no detectable sucrose content. In addition, it was also found that unsweeten juices contained considerable level of sucrose. Chemometric technique such as principal components analysis was applied to provide an overview of the distinguishability of fruit juices based on HPLC or GC data. Principal components plot showed that different fruit juices grouped into distinct cluster. Principal components analysis was very useful in fruit juices industry for many aspects such as pattern recognition, detection of adulterants, and quality evaluation.