• The Korean Journal of Ecology
• /
• v.28 no.5
• /
• pp.295-303
• /
• 2005

The sexual dimorphism and intra sexual dimorphism in males of Rhinogobius brunneus were investigated at Jiam stream, a tributary of the Bukhan river from May, 2005. The frequency distributions in standard length were similar for the females and maleLs, but maleSs were smaller than the females and maleLs. The ratio of MaleL (N=79) to males (N=79) was 1 : 0.46. The comparison between female (N=79) and maleL (N=79) gave significant differences (P<0.05) in 18 morphometric characteristics (SNL, AHD, PHD, ML, DL, MW, AHW, IFW, PHW, ED, HL, FDFL, SDFB, CFL, AFB, VFL, PFL, PFB) and 12 characteristics (SNL, AHD, ML, DL, MW, AHW, IFW, PHW, HL, FDFI, CFL, PFB) (P<0.001). Eight morphometric characteristics (SNL, ML, DL, MW, HL, CFL, VFL, PFL) in female (N=36) and males (N=36) had significant differences (P<0.05) and three characteristics (ML, DL, HL) had very significant differences (P<0.001). Eleven characteristics (SNL, AHD, PHD, ML, DL, MW, AHW, IFW, PHW, HL, FDFL) were significantly different in maleL (N=36) and males (N=36) (P<0.05) and six (ML, DL, MW, AHW, HL, FDFL) were very significantly different (P<0.001).

• Korean Journal of Radiology
• /
• v.22 no.3
• /
• pp.384-394
• /
• 2021

Objective: To quantitatively assess biochemical alterations in the cartilage of the subtalar and midtarsal joints in chronic lateral ankle instability (CLAI) patients with isolated anterior talofibular ligament (ATFL) injuries and combined calcaneofibular ligament (CFL) injuries using MRI T2 mapping. Materials and Methods: This study was performed according to regulations of the Committee for Human Research at our institution, and written informed consent was obtained from all participants. Forty CLAI patients (26 with isolated ATFL injuries and 14 with combined ATFL and CFL injuries) and 25 healthy subjects were recruited for this study. All participants underwent MRI scans with T2 mapping. Patients were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system. The subtalar and midtarsal joints were segmented into 14 cartilage subregions. The T2 value of each subregion was measured from T2 mapping images. Data were analyzed with ANOVA, the Student's t test, and Pearson's correlation coefficient. Results: T2 values of most subregions of the subtalar joint and the calcaneal facet of the calcaneocuboid joint in CLAI patients with combined CFL injuries were higher than those in healthy controls (all p < 0.05). However, there were no significant differences in T2 values in subtalar and midtarsal joints between patients with isolated ATFL injuries and healthy controls (all p > 0.05). Moreover, T2 values of the medial talar subregions of the posterior subtalar joint in patients with combined CFL injuries showed negative correlations with the AOFAS scores (r = -0.687, p = 0.007; r = -0.609, p = 0.021, respectively). Conclusion: CLAI with combined CFL injuries can lead to cartilage degeneration in subtalar and calcaneocuboid joints, while an isolated ATFL injury might not have a significant impact on the cartilage in these joints.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.2
• /
• pp.162-168
• /
• 2014

Use of nonlinear loads, such as power converters, fluorescent lamps and adjustable speed motor drives, is expected to grow rapidly. All of these loads inject harmonic currents. This paper presents the active filtering of the harmonic distortion generated by the compact fluorescent lamps (CFL). The Instantaneous active and reactive power theory (the p-q Theory) is used to design the control of parallel active filter. The control scheme has been verified using Matlab/Simulink with SimPower Systems through a set of simulation tests under different load conditions. Also, the tuning of the active power filter is performed to improve the quality of the electrical power supply.

• Interaction and multiscale mechanics
• /
• v.3 no.2
• /
• pp.111-121
• /
• 2010

Dynamic analysis of nano/micro bio-sensors based on a multiscale atomistic/continuum theory is introduced. We use a generalized atomistic finite element method (GAFEM) to analyze a bio-sensor which has $3{\times}N_a{\times}N_p$ degrees of freedom, where $N_p$ is the number of representative unit cells and $N_a$ is the number of atoms per unit cell. The stiffness matrix is derived from interatomic potential between pairs of atoms. This work contains two studies: (1) the resonance analysis of nano bio-sensors with different amount of target analyte and (2) the dependence of resonance frequency on finite element mesh. We also examine the Courant-Friedrichs-Lewy (CFL) condition based on the highest resonance frequency. The CFL condition is the criterion for the time step used in the dynamic analysis by GAFEM. Our studies can be utilized to predict the performance of micro/nano bio-sensors from atomistic perspective.

• Research in Plant Disease
• /
• v.9 no.3
• /
• pp.116-120
• /
• 2003

A PCR method that combines biological and enzymatic amplification of PCR targets was developed for the detection of Pseudomonas syringae pv. actinidiae on kiwifruit leaves. A nested PCR was performed with primers designes from the coding sequence of the cfl gene, which is involved in production of the phytotoxin coronatine. The first and second primer sets efficiently amplified expected 665 and 310-bp fragments, respectively. With two successive amplifications, as few as 20 CFU/ml of P. syringae pv. actinidiae could be detected on ethidium bromide-stained agarose gel. Leaf samples were collected from 4 kiwifruit trees showing yellow halo spots on leaves and incubated in pepton-sucrose broth for 12 h at $16^{\circ}$C before PCR amplification. Positive detection was obtained with one sample, which was proved as a diseased plant in the next spring.

• Atmosphere
• /
• v.33 no.4
• /
• pp.331-341
• /
• 2023

A numerical forecasting models usually predict future states by performing time integration considering fixed static time-steps. A time-step that is too long can cause model instability and failure of forecast simulation, and a time-step that is too short can cause unnecessary time integration calculations. Thus, in numerical models, the time-step size can be determined by the CFL (Courant-Friedrichs-Lewy)-condition, and this condition acts as a necessary condition for finding a numerical solution. A static time-step is defined as using the same fixed time-step for time integration. On the other hand, applying a different time-step for each integration while guaranteeing the stability of the solution in time advancement is called an adaptive time-step. The adaptive time-step algorithm is a method of presenting the maximum usable time-step suitable for each integration based on the CFL-condition for the adaptive time-step. In this paper, the adaptive time-step algorithm is applied for the Korean Integrated Model (KIM) to determine suitable parameters used for the adaptive time-step algorithm through the monthly verifications of 10-day simulations (during January and July 2017) at about 12 km resolution. By comparing the numerical results obtained by applying the 25 second static time-step to KIM in Supercomputer 5 (Nurion), it shows similar results in terms of forecast quality, presents the maximum available time-step for each integration, and improves the calculation efficiency by reducing the number of total time integrations by 19%.

• Environmental Engineering Research
• /
• v.21 no.2
• /
• pp.171-179
• /
• 2016

This study analyzes guidelines to select optimum number of grids to represent behavior of a given water system appropriately. The EFDC model was chosen as a 3-D hydrodynamic and water quality model and salt was chosen as a surrogate variable of pollutant. The model is applied to an artificial canal that receives salt water from coastal area and fresh water from a river from respective gate according to previously developed gate operation rule. Grids are subdivided in vertical and horizontal (longitudinal) directions, respectively until no significant changes are found in salinity concentrations. The optimum grid size was determined by comparing errors in average salt concentrations between a test grid systems against the most complicated grid system. MSE (mean squared error) and MAE (mean absolute error) are used to compare errors. The CFL (Courant-Friedrichs-Lewy) number was used to determine the optimum number of grid systems for the study site though it can be used when explicit numerical method is applied only. This study suggests errors seem acceptable when both MSE and MAE are less than unity approximately.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.44 no.10
• /
• pp.178-184
• /
• 2007

A new adaptive alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method is proposed to obtain isotropic wave propagation for all directional angles. We add the square terms of time-step multiplied by the spatial derivatives of x and y as a perturbed term to the conventional ADI-FDTD and can find the optimization coefficient of square terms of time-step to generate the minimum anisotropy. The new ADI-FDTD is also stable, even when its time-step is greater than the Courant-Friedrich-Levy (CFL) limit. The characteristic equation of the dispersion relation governing the new method is derived and compared with the theoretical and numerical results for the conventional ADI-FDTD and perturbed ADI-FDTD methods.

• Journal of Ocean Engineering and Technology
• /
• v.32 no.3
• /
• pp.166-176
• /
• 2018

This paper presents a numerical sensitivity analysis for the simulation of the motion performance of an offshore structure in waves using computational fluid dynamics (CFD). Starting with 2D wave simulations with varying numerical parameters such as grid spacing and CFL value, proper numerical conditions were found for accurate wave propagation that avoids numerical diffusion problems. These results were mapped on 2D error distributions of wave amplitude and wave length against the numbers of grids per wave length and per wave height under a given CFL condition. Finally, the 2D numerical sensitivity result was validated through CFD simulation of the motion of a FPSO in waves showing good accuracy in motion RAOs compared with existing potential flow solutions.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.12 no.2
• /
• pp.151-159
• /
• 1992

In close-range photogrammetry, to employ non-metric camera especially for the purpose of precise measurement, systematic errors must, first of all, be corrected as they have a great influence on accuracies of results. For it, fiducial marks was built in non-metric camera and the factors such as PPS, PPA, EFL, CFL, and radial lens distortion coefficients for each quadrant were calibrated through collimator test. Also, the coefficients of both radial and tangential lens distortion were calibrated from analytical plumb line method and therefore main systematic errors could be effectively corrected. Using the calibrated non-metric camera, close-range photogrammetry could be successfully accomplished and accuracies could be improved sharply.