• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.58-65
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• 2010

For the improvement of fuel consumption, the study on the use of lightweight material or thinner sheet have been carried out in automotive industry. With the need for the use of thinner sheet, the dent resistance became one of the major concern in th design of exterior panels in automotive industry. Many studies have been carried out for the dent resistance by experiment or quasi-static numerical simulation. In this study, the dent formation behavior is investigated by dynamic finite element analysis using ABAQUS. Dent formation may be affected by many factors such as sheet thickness, material properties, pre-strain, and sheet curvature. The effect of these factors on dent resistance is investigated. From the analysis following three conclusions are derived. First, dent resistance become hard as the sheet curvature radius increases. Second, dynamic dent resistance is mainly affected by bending stress rather than tensile stress. Third, the pre-strain itself do not give any guidance for dynamic dent resistance and dynamic dent resistance have to be decided considering the strain hardening and thickness reduction together. The results are considered to be reliable and useful to improve the dent damage of automotive panels.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.322-325
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• 2007

Dent resistance is an important characteristic to avoid damage on automotive outer panels. From a practical point of view, dents can be caused in a number of ways. Considering doors as an example, denting can occur from stone impacts or from the careless opening of an adjacently parked vehicle door. Denting can occur where the door surface is smooth and may not have sufficient curvature to resist dent. These exterior body parts are designed to improve dent resistance using a combination of work hardening and bake hardening. In brief, dent is affected by the shape of the parts and the material properties such as yield strength, strain and thickness. In this work, forming of door outer panel is investigated by Taguchi method. Main parameters are yield strength, thickness, blank size, blank holding force and so on. For the given value of design parameters, forming analysis of the thirty six cases are carried out according to L18 orthogonal array. After comparing the performance by simple conversion of simulation results into dent resistance, the final suggestion of the forming parameters is verified for the best improvement of dent resistance.

• Transactions of Materials Processing
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• v.16 no.4 s.94
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• pp.254-259
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• 2007

Dent resistance is an important characteristic to avoid damage on automotive outer panels. From a practical point of view, dents can be caused in a number of ways. Considering doors as an example, denting can occur from stone impacts or from the careless opening of an adjacently parked vehicle door. Denting can occur where the door surface is smooth and may not have sufficient curvature to resist dent. These exterior body parts are designed to improve dent resistance using a combination of work hardening and bake hardening. In brief, dent is affected by the shape of the parts and the material properties such as yield strength, strain and thickness. In this work, forming of door outer panel is investigated by Taguchi method. Main parameters are yield strength, thickness, blank size, blank holding force and so on. For the given value of design parameters, forming analysis of the eighteen cases are carried out according to L18 orthogonal array. After comparing the performance by simple conversion of simulation results into dent resistance, the final suggestion of the forming parameters is verified for the optimal improvement of dent resistance.

• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.1-7
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• 2010

Over the past few decades various experimental and theoretical investigations have been performed on offshore tubular members with regard to damage resistance and residual strength. Analysis of damaged tubular members requires a three-dimensional shell analysis for accurate results. Even though various commercial packages are available for this purpose, a beam-column analysis is preferred for offshore structural designs. In this paper, empirical equations are provided for a more accurate beam-column analysis of damaged tubes including the relationships between the lateral denting load and the depth of the dent, the rate of dent deepening due to increasing curvature and the longitudinal variation in the dent depth of damaged tubes. A design equation to predict the ultimate bending capacities of damaged offshore tubular members is also presented.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.337-353
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• 2018

We used Illumina/HiSeq sequencing for analysis of gene expression profiling among four maize seed types (dent, CM3 and CM6; waxy, CM5 and CM19) at 10 DAP (days after pollination). A total of 88,993,000 (CM3), 103,817,340 (CM6), 103,139,640 (CM5), and 66,978,958 (CM19) sequence reads were generated with read lengths of about 0.9, 1.0, 1.0, and 0.7 billion bp, respectively. We obtained 69.1 (CM3), 71.0 (CM6), 71.2 (CM5), and 71.8% (CM19) high quality reads from the raw data and compared them with reference RNA sequences in a public DB (NCBI). It was revealed that mapped reads were 58%, 63%, 62%, and 62% of the EST reference in CM3, CM6, CM5 and CM19, respectively; and more than 51,000 genes were expressed based on RPKM criteria (over 0.25 value) in each CM3, CM6, CM5, and CM19 inbred line. In differentially expressed gene (DEG) analysis, we found that 3,527 genes were differentially expressed by at least two-fold with 1,709 upregulated in the two waxy inbred lines and 1,818 upregulated in the two dent inbred lines. We also detected genes for the sucrose and starch biosynthesis pathways based on BINs, and different expression patterns between waxy and dent inbred lines were shown for the gene set for starch synthesis, such as sh2, bt2, du1, wx1, and ae1. Although some genes were more expressed in dent lines, most genes for starch synthesis were much expressed in waxy lines. Especially, there was greater expression of the sus2 gene in both waxy lines compared with the dent lines.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.2009-2020
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• 2004

A parametric study of the factors controlling static and dynamic denting, as well as local stiffness, has been made on simplified panels of different sizes, curvatures, thicknesses and strengths. Analyses have been performed using the finite element method to predict dent resistance and panel stiffness. A parametric approach is used with finite element models of simplified panels. Two sizes of panels with square plan dimensions and a wide range of curvatures are analysed for several combinations of material thickness and strength, all representative of auto-motive closure panels. Analysis was performed using the implicit finite element code, LS-NIKE, and the explicit dynamic code, LS-DYNA for the static and dynamic cases, respectively. Panel dent resistance and stiffness behaviour are shown to be complex phenomena and strongly interrelated. Factors favouring improved dent resistance include increased yield strength and panel thickness. Panel stiffness also increases with thickness and with higher curvatures but decreases with size and very low curvatures. Conditions for best dynamic and static dent performance are shown to be inherently in conflict ; that is, panels with low stiffness tend to perform well under impact loading but demonstrate inferior static dent performance. Stiffer panels are prone to larger dynamic dents due to higher contact forces but exhibit good static performance through increased resistance to oil canning.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.85-101
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• 2022

Objective: To classify facial asymmetry (FA) phenotypes in adult patients with skeletal Class III (C-III) malocclusion. Methods: A total of 120 C-III patients who underwent orthognathic surgery (OGS) and whose three-dimensional computed tomography images were taken one month prior to OGS were evaluated. Thirty hard tissue landmarks were identified. After measurement of 22 variables, including cant (°, mm), shift (mm), and yaw (°) of the maxilla, maxillary dentition (Max-dent), mandibular dentition, mandible, and mandibular border (Man-border) and differences in the frontal ramus angle (FRA, °) and ramus height (RH, mm), K-means cluster analysis was conducted using three variables (cant in the Max-dent [mm] and shift [mm] and yaw [°] in the Manborder). Statistical analyses were conducted to characterize the differences in the FA variables among the clusters. Results: The FA phenotypes were classified into five types: 1) non-asymmetry type (35.8%); 2) maxillary-cant type (14.2%; severe cant of the Max-dent, mild shift of the Man-border); 3) mandibular-shift and yaw type (16.7%; moderate shift and yaw of the Man-border, mild RH-difference); 4) complex type (9.2%; severe cant of the Max-dent, moderate cant, severe shift, and severe yaw of the Man-border, moderate differences in FRA and RH); and 5) maxillary reverse-cant type (24.2%; reverse-cant of the Max-dent). Strategic decompensation by pre-surgical orthodontic treatment and considerations for OGS planning were proposed according to the FA phenotypes. Conclusions: This FA phenotype classification may be an effective tool for differential diagnosis and surgical planning for Class III patients with FA.

• Childhood Kidney Diseases
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• v.19 no.2
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• pp.65-70
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• 2015

It is well known that proteins present in the primary urine are reabsorbed in the renal proximal tubules, and that this reabsorption is mediated via the megalin-cubilin complex and the neonatal $Fc{\gamma}$ receptor. However, the reabsorption is also thought to be influenced by an electrostatic interaction between protein molecules and the microvilli of the renal proximal tubules. By analyzing the charge diversity of urinary IgG, we showed that this reabsorption process occurs in a cationic charge-preferential manner. The charge-selective molecular sieving function of the glomerular capillary walls has long been a target of research since Brenner et al. demonstrated the existence of this function by a differential clearance study by using the anionic dextran sulfate polymer. However, conclusive evidence was not obtained when the study was performed using differential clearance of serum proteins. We noted that immunoglobulin (Ig) A and IgG have similar molecular sizes but distinct molecular isoelectric points. Therefore, we studied the differential clearance of these serum proteins (clearance IgA/clearance IgG) in podocyte diseases and glomerulonephritis. In addition, we studied this differential clearance in patients with Dent disease rather than in normal subjects because the glomerular sieving function is considered to be normal in subjects with Dent disease. Our results clearly showed that the charge-selective barrier is operational in Dent disease, impaired in podocyte disease, and lacking in glomerulonephritis.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.201-203
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• 2006

This paper presents a graphical windows-based software for the education and training of the transmission network use of system charge. The developed simulator consist of the main module(MMI,GUI), the power flow module(PF), the power flow tracing module(PFT) and management of usage cost DB module(UCD). Each module has a separate graphical and interactive interfacing window. To have effective education for transmission network use of system charge, the developed simulator are provided with two power system analysis methods. Input data of power system can use the format of PSS/E input data. Also calculation of power flow tracing are provided with four methods such as "Felix Wu","Modified Felix Wu", "DCLF ICRP" and "Reverse MW mile". Results of calculation for usage cost are shown on the window through the table or chart. Therefore user can confirm the detailed differences of results from each calculation method.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.8 no.3
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• pp.7-12
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• 2012

Steam generator tubes are critical boundary of the primary and secondary side in nuclear power plants. Eddy current testing is commonly used as the method of non-destructive testing for the safety and integrity of steam generator tubes in the nuclear power plants. Changes in the geometric shape act as a stress concentration factor likely to cause a defect during the steam generator operation. The mixed-signals with the geometric shape are distorted and attributes that are difficult to detect signals. An example is bending stress due to compression process at a U-bend occurring in the intrados region which has a small radius of curvature. The resulting change in the geometric shape may lead to a dent like occurrences. The dent can cause stress concentration and generates stress corrosion cracks. In this study, the steam generator tubes of nuclear power plant were selected to study for analysis of mixed-signal containing dent and stress corrosion cracks.