• Proceedings of the KSME Conference
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• 2001.06e
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• pp.386-391
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• 2001

A finite element code based on P2P1 tetra element has been developed for the large eddy simulation (LES) of turbulent flows around a complex geometry. Fractional 4-step algorithm is employed to obtain time accurate solution since it is less expensive than the integrated formulation, in which the velocity and pressure fields are solved at the same time. Crank-Nicolson method is used for second order temporal discretization and Galerkin method is adopted for spatial discretization. For very high Reynolds number flows, which would require a formidable number of nodes to resolve the flow field, SUPG (Streamline Upwind Petrov-Galerkin) method is applied to the quadratic interpolation function for velocity variables, Noting that the calculation of intrinsic time scale is very complicated when using SUPG for quadratic tetra element of velocity variables, the present study uses a unique intrinsic time scale proposed by Codina et al. since it makes the present three-dimensional unstructured code much simpler in terms of implementing SUPG. In order to see the effect of numerical diffusion caused by using an upwind scheme (SUPG), those obtained from P2P1 Galerkin method and P2P1 Petrov-Galerkin approach are compared for the flow around a sphere at some Reynolds number. Smagorinsky model is adopted as subgrid scale models in the context of P2P1 finite element method. As a benchmark problem for code validation, turbulent flows around a sphere and a MIRA model have been studied at various Reynolds numbers.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1129-1134
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• 2001

In the point of the Eco-concrete(Environmentally Friendly Concrete), it is very important to reduce the pH of high porous concrete by the pH to be able to grow plants, because the pH of concrete is l1~13. But the method of measuring the pH of high porous concrete is not well-defined, yet. Therefore, first, this paper report the method of measuring the pH of high porous concrete. Secondly this paper reports the pH reduction of high porous concrete to grow plants.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.290-295
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• 1992

Tendon driven method to drive one joint using two actuators is developed and implemented. While the method has advantages over conventional transmissions, it also has several drawbacks like tendon slack, elongation and endurability. In this paper, a compensation method of the intrinsic non-linearities of tendon is proposed to improve the performance of antagonistic tendon driven method. In this method, tendon tension measurement is prerequisite which is measured with strain gauge type tension sensor. The developed method is implemented on one link test bed with colocated and non-colocated position sensor.

• Child Health Nursing Research
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• v.10 no.3
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• pp.251-261
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• 2004

Purpose: To investigate the degree and sources of stress which fathers of infants in NICU experience. Method: Eighty-five fathers of NICU infants at 5 university hospitals in Seoul volunteered to complete the Parental Stressor Scale for NICU (PSS: NICU) from September 1, to October 15, 2002. Result: Total perceived stress was 3.50±0.76. The highest score were in Parental Role Alteration (3.76±0.83) and Appearance and Behavior (3.65±1.04). The total perceived stress score (PSS), correlated significantly with method (t=3.50, p=.01), and route (F=5.30, p=.00) of feeding. Light & Sound correlated significantly with birth weight (F=3.39, p=.02), medical diagnosis(F=2.30, p=.03), plan of operation(t=2.50, p=.01), operation (t=3.80, p=.02), method (F=4.90, p=.003), and route (F=4.70, p=.00) of feeding. Infant Appearance and Behavior correlated significantly with birth weight (F=5.12, p=.01), plan of operation (t=2.50, p=.01), method (F=3.50, p=.01), and route (F=7.80, p=.00) of feeding. Parental Role Alteration correlated significantly with care of incubator (t=-.68, p=.03), method of feeding (F=2.80, p=.04) and education level of father (F=3.00, p=.05). Conclusion: Father with NICU infants were concerned mostly with parental role alteration and infant appearance. Nursing intervention should include fathers of NICU infants.

• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.1-6
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• 2023

Sound radiated from a structure in vibration is an important physical characteristic to evaluate vibro-acoustic problem. Although sound radiation power can be typically obtained by intensity measurement, long measuring time and strict measuring condition remain difficult. As an alternative method, simulation-based estimation can be taken into account and its accuracy is known to be acceptable. However, difficulty still lies in that specialized softwares may be necessary to obtain sound radiation power and radiation efficiency. In this context, this study suggests two methods using an ordinary FE method to calculate sound radiation power. They are well-known reciprocity technique and p-p method, which are basically test methods. It is shown that either method can practically estimate sound radiation in the frame of conventional Finite Element Method (FEM). The methods and their corresponding limit are discussed with some results.

• Journal of the Korean Society of Costume
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• v.33
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• pp.217-228
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• 1997

The purpose of this study was to investigate influence of the construction method of the circular skirt on drapability and shape of static silhouette and length variation. In made 24 types of skirts giving the variations (six kinds of peach skin-like finished fabrics two types of cutting method two types of machine stitch method of hem), The results were as follows: 1. Analysis of drapability In the cutting method thre was similarity between warp direction and true bias direc-tion. In the machine stitch method of hem there was similarity between blind stitch and blind stitch machine. According to the fabrics analysis of drapability was excellent in the order N/P 80/20(fabric 1)>P 100(fabric 5)>P 100(fabric 6)>P 100 (fabric 2)>P 100 (fabric 4)>N/C 50/50(fabric 3). 2. Analysis of the characteristics values of static silhouette shape In the cutting method shape of static sil-houette became wide in the warp direction. In the machine stitch method of hem shape of static silhouette became wide in the blind stitch. According to the fabrics shape of static silhouette became most wide in the N/C 50/50(fabric 3) and shape of static sil-houette become most narrow in the P 100(fabric 2,5) 3. Analysis of the length variation In the cutting method the true bias direc-tion was longer than the warp direction. In the machine stitch method of hem there was simi-machine stitch method of hem there was simi-larity between blind stitch and blind stitch ma-chine. In fabrics the P 100(fabric 6) showed the longest the N/C 50/50(fabric 3) showed most slight. Interaction between the cutting and messure-ment part of skirt lengh. In the warp diretion parts that showed longest length variation were C. G, K, O in the true bias diretion parts that showed most slight length variation were A, E, M, I.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.55-62
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• 2014

Objectives: $^{32}P$-postlabeling assay is the most sensitive method of detecting DNA adduct formation. However, it is limited by a low sample throughput and use of radioisotopes (RI). In this study, we modified it to minimize these limitations and applied it to Z. platypus exposed to Benzo(a)pyrene (BaP) in order to investigate DNA adduct formation (effect biomarker for pollutants) in Z. platypus for assessing risk of waterborne BaP exposure. Methods: DNA hydrolysis was performed only with Micrococcal nuclease (MNase), RI reduction test was performed and the overlapping steps between thin layer chromatography (TLC) and radioisotope high-performance liquid chromatography (RI-HPLC) were omitted. The application of a modified method to Z. platypus exposed to BaP was performed. Results: The results revealed that the amount of RIs used can be reduced roughly 10-fold. Because the analysis time was shortened by 8.5 hours, the sample throughput per hour was increased compared with the previous method. The results of applying modified $^{32}P$-postlabeling assay to Z. platypus, DNA adduct formation in Z. platypus showed dose-dependency with the BaP concentration. Only BPDE-dGMP was detected as a DNA adduct. Conclusion: These results demonstrate that the modified $^{32}P$-postlabeling assay is a suitable method for detecting DNA adduct formation in Z. platypus exposed to waterborne BaP and will be useful in risk assessment of carcinogenic effect in aquatic environment due to BaP.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.99-108
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• 2001

A framework of using and integrating GIS and OR tools for determining the best site selection has been provided. In this research, we demonstrated that both the P-Median heuristic method and MIP method can be successfully applied to the optimum site selection problem of oil tank location selection. Furthermore, the results identified by both approaches are identical. To accomplish this, both GIS road and maritime networks have been constructed and combined to calculated the minimum distance matrix, which is required by both approaches. After the application to the Korean peninsula, the facility locations chosen are Kunsan, Yosu, Busan, and Okgye for each district. As has been shown, the power of GIS and both algorithm have been demonstrated throughout the research and further similar research can also be conducted using the power of GIS and Operations Research tools.

• Journal of the Korean Mathematical Society
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• v.60 no.1
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• pp.1-32
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• 2023

In this paper, we present a method of characterizing minimal polynomials on the ring 𝐙_p of p-adic integers in terms of their coefficients for an arbitrary prime p. We first revisit and provide alternative proofs of the known minimality criteria given by Larin [11] for p = 2 and Durand and Paccaut [6] for p = 3, and then we show that for any prime p ≥ 5, the proposed method enables us to classify all possible minimal polynomials on 𝐙_p in terms of their coefficients, provided that two prescribed prerequisites for minimality are satisfied.

• The Korean Journal of Applied Statistics
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• v.26 no.5
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• pp.797-806
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• 2013

Meta-analysis is used in variety of areas to synthesize the results of previous studies. Among the methods for Meta-analysis, combining p-values is the simplest method; in addition Tippett (1931), Fisher (1932), Stuoffer at al. (1949), proposed various methods to combine p-values. We propose a new method to combine p-values based on exponential distribution. A Monte Carlo simulation study compares the power of the proposed methods with previous methods.