• Environmental Analysis Health and Toxicology
• /
• v.21 no.4 s.55
• /
• pp.365-373
• /
• 2006

Emission of methyl bromide (MeBr) from soil was implicated in stratospheric ozone depletion. To determine multi analysis of alternatives fumigants for MeBr, this paper describes the methods of analysis in water and soil. The MeBr, methyl iodide (Mel), propargyl bromide (PBr), cis 1,3-dichloropropene (cis 1,3-D), trans 1,3-dichloropropene (trans 1,3-D) and chloropicrin(CP) are separated on the base line on GC-ECD at three column of AT+DB+DB (90m) with temperature programing of $35^{\circ}C{\rightarrow}110^{\circ}C$ on GC-ECD. The relative retention time for MeBr, Mel, PBr, cis 1,3-D, trans 1,3-D and CP is 1.0, 1.4, 2.3, 3.2, 3.6 and 3.7, respertively. The detection limit for MeBr, Mel, PBr, cis 1,3-D, trans 1,3-D and CP is 469 pg, 5 pg, 21 pg, 79 pg, 101 PE and 5pg, respectively. Recovery of MeBr Mel, PBr, cis 1,3-D, trans 1,3-D and CP in water added 150 ppm fumigants were 81%, 96%, 95%, 97%, 98% and 99%, respectively. Recovery of MeBr, MeI, PBr, cis 1, 3-D, trans 1,3-D and CP in soil added 150ppm fumigants were 56%, 84%), 85%, 81%, 87% and 88%, respectively.

• Nuclear Engineering and Technology
• /
• v.55 no.4
• /
• pp.1350-1364
• /
• 2023

2D/1D coupling method is an important neutron transport calculation method due to its high accuracy and relatively low computation cost. However, 2D/1D coupling method may diverge especially in small axial mesh size. To analyze the convergence behavior of 2D/1D coupling method, a Fourier analysis for k-eigenvalue neutron transport problems is implemented. The analysis results present the divergence problem of 2D/1D coupling method in small axial mesh size. Several common attempts are made to solve the divergence problem, which are to increase the number of inner iterations of the 2D or 1D calculation, and two times 1D calculations per outer iteration. However, these attempts only could improve the convergence rate but cannot deal with the divergence problem of 2D/1D coupling method thoroughly. Moreover, the choice of axial solvers, such as DGFEM SN and traditional SN, and its effect on the convergence behavior are also discussed. The results show that the choice of axial solver is a key point for the convergence of 2D/1D method. The DGFEM SN based 2D/1D method could converge within a wide range of optical thickness region, which is superior to that of traditional SN method.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.2
• /
• pp.161-168
• /
• 2016

CNG engine has been used as a transportation because of higher thermal efficiency and lower CO2 and particulate matter. However its out put power is decreased due to cylinder-to-cylinder variation during the supply of air-fuel mixture to the each cylinder. It also causes noise and vibration. So in this study, 1D engine simulation model was validated by comparison with experiment data and 3D CFD simulation was conducted to steady-state flow analysis about each manifold geometry. Then, the effects of various intake manifold geometries on variation were evaluated by using 1D-3D coupling analysis at engine speed of 2100 rpm range in 12 L CNG engine. As a result, variation was improved about 4 % though 3D CFD analysis and there was a variation within 3 % using 1D-3D coupling analysis.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.3
• /
• pp.67-76
• /
• 2012

In this paper, collision analysis of the full rake for the Next Generation High-speed EMU is conducted using a 3D/1D hybrid model, which combines 3-dimensional (3D) front-end structure of finite element model and 1-dimensional (1D) multi-body dynamics model in order to analyze train collision with a standard 3D deformable obstacle. The crush forces, passengers' accelerations and energy absorptions of a full rake train can be easily obtained through a simulation of a 1D dynamics model composed of nonlinear springs, dampers and masses. Also the obtained simulation results are very similar to those of a 3D model if an overriding behavior does not occur during collision. The standard obstacle in TSI regulation has been changed from a rigid body to a deformable body, and therefore 3D collision simulations should be conducted because their simulation results depends on the front-end structure of a train. According to the obstacle collision analysis of this study, the obstacle collides with the driver's upper structure after overriding over the front-end module. The 3D/1D hybrid model is effective to evaluate a main energy-absorbing module that is frequently changed during design process and reduce the need time of the modeling and analysis when compared to a 3D full car body.

• Nuclear Engineering and Technology
• /
• v.54 no.3
• /
• pp.1109-1114
• /
• 2022

The SMART (System-integrated Modular Advanced ReacTor) is an integral-type small modular reactor developed by KAERI (Korea Atomic Energy Research Institute). This paper discusses the feasibility and applicability of a 3D-based equivalent model using dynamic condensation method for seismic analysis of a SMART control rod drive mechanism. The equivalent model is utilized for complicated seismic analysis during the design of the SMART. While the 1D-based beam-mass equivalent model is widely used in the nuclear industry for its calculation efficiency, the 3D-based equivalent model is suggested for the seismic analysis of SMART to enhance the analysis accuracy of the 1D-based equivalent model while maintaining its analysis efficiency. To verify the suggested model, acceleration response spectra from seismic analysis based on the 3D-based equivalent model are compared to those from the 1D-based beam-mass equivalent model and experiments. The accuracy and efficiency of the dynamic condensation method are investigated by comparison to analysis results based on the conventional modeling methodology used for seismic analysis.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.1
• /
• pp.1-12
• /
• 2003

The purpose of this study was to design the method of 3D space calibration to reduce RMSE by statistical analysis when using the DLT algorithm and control frame. Control frame for 3D space calibration was consist of $1{\times}3{\times}2m$ and 162 contort points adhere to it. For calculate of 3D coordination used two methods about 2D coordination on image frame, 2D coordinate on each image frame and mean coordination. The methods of statistical analysis used one-way ANOVA and T-test. Significant level was ${\alpha}=.05$. The compose of methods for reduce RMSE were as follow. 1. Use the control frame composed of 24-44 control points arranged equally. 2. When photographing, locate control frame to center of image plane(image frame) o. use the lens of a few distortion. 3. When calculate of 3D coordination, use mean of 2D coordinate obtainable from all image frames.

• Nutrition Research and Practice
• /
• v.5 no.5
• /
• pp.464-470
• /
• 2011

Growing evidence suggests an elevated risk for colorectal neoplasia among individuals with low levels of vitamin D, the biological actions of which are mediated by the vitamin D receptor (VDR). To investigate the association among vitamin D status, VDR polymorphisms (FokI, and BsmI), and colorectal adenoma, we conducted a meta-analysis of nine studies of circulating levels of 25-hydroxyvitamin D (25(OH)D) and five studies of FokI or BsmI polymorphisms in relation to colorectal adenomas. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were pooled using a random-effects model. A total of 3398 coloreetal adenomas for 25(OH)D and 1754 colorectal adenomas for VDR were included in the meta-analysis. We identified a significant inverse association between colorectal adenoma (combined RR, 0.93; 95% CI, 0.87-0.98 per 10 ng/mL increase in 25(OH)D levels). When we examined FokI and BsmI polymorphisms in the meta-analysis, we found no association for either FokI (combined RR, 1.00; 95% CI, 0.95-1.06) or BsmI (combined RR, 0.99; 95% CI, 0.93-1.05) in the additive model. These data suggest an inverse association between circulating 25(OH)D levels and colorectal adenoma risk.

• Korea Trade Review
• /
• v.45 no.1
• /
• pp.47-64
• /
• 2020

For the past few years, the Korean government has been consistently expanding its national research & development budget to accelerate economic growth through technology innovation and the enhancement of international competitiveness in global markets. The objective of this paper is to define the concept and analyze the current status of national R&D programs by measuring R&D efficiencies. We determine R&D efficiency by reflecting inputs and outcomes of the five main agricultural R&D programs between 2010 to 2015, and by categorizing and regrouping figures that may affect R&D performance. Among 1,128 targeted projects, 832 projects with patents and thesis were selected for analysis in terms of measuring technology efficiency, pure technology efficiency, and efficiency of scale. Also, the Kruskal-Wallis test was also utilized as well. As a result of empirical analysis, figures that affected the efficiency level of national R&D programs included differences in research resources, research management levels and skills, and research field. This study can be utilized as a reference for re-establishing national agricultural R&D policies, such as enhancement of national technology competitiveness in the global market environment, improving and adapting to new agricultural conditions, market expansion, national agricultural R&D efficiency, aging rural population, agricultural management cost increase, and climate change mitigation.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.7
• /
• pp.3615-3617
• /
• 2016

Background: Breast cancer molecular analysis by linkage analysis has the advantage of facilitating early diagnosis in asymptomatic genetic carriers, with a view to the preventive follow-up of these subjects and genetic counseling. The aim of this study was to evaluate BRCA1 gene D17S855 and D17S1322 markers in breast cancer patients. Materials and Methods: A series of 85 BC patients and 85 unrelated healthy women were recruited for haplotype analysis performed using two short tandem repeat markers located within the BRCA1 gene locus. Each marker was amplified with PCR genomic DNA from each individual and fluorescently end-labeled primers. Results: Both D17S855 and D17S1322 markers included 12 kinds of alleles. Results indicate that most of the BC patients shared two common 121-150 (11.2%, RR=1.56 and p=0.02) and 121-146 (5.6%, RR=1.9 and p=0.02) haplotypes. Conclusions: Our results should be helpful to understand the haplotype phase in the BRCA1 gene and establish a genetic screening strategy in the Iranian population.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.6 s.144
• /
• pp.631-636
• /
• 2005

One and three dimensional whipping response analyses of a naval surface combatant subjected to an underwater explosion bubble pulse were carried out to compare the efficiency and accuracy according to the modeling methods. In 1-D analysis, program UNDEXWHIP developed by KIMM was used, which is based on the thin-walled Timoshenko's beam theory and on the modal analysis method using wetted vibratory modes of the hull girder. In 3-D analysis, three finite element models were suggested using LS-DYNA/USA code, such as 3-D beam model considering geometric shape of wetted side shell, coarse and fine 3-D F.E. models. Through the comparison of results from the 1-D and 3-D analyses, it could be confirmed that 1-D analysis result is in good agreement with 3-D analysis ones, and that fine 3-D F.E. model, shock analysis one, is also used both in the shock response and whipping response analyses for the analyst effort and time savings.