• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.141-152
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• 1992

Four endodontic instruments from different manufacturers(K - file, Hedstrom - file, K - flex - file, Cavi - Endo) were used to shape 80 mesial canals of extracted posterior teeth. The instrument's ability to enlarge and shape the canals as the original canal shape was assessed by superimposing radiographs of canals obtained before and after canal shaping. The results were as follows 1. Hedstrom - file enlarged canals greater than K - file, K - flex - file, and Cavi - Endo(P<0.05). There are no differences in canal enlargement among K - flex, K - flex - file, and Cavi - Endo(P<0.05). 2. All the instruments showed no difference in canal enlargement between convex side and concave side of B point in proximal and clinical radiographic views, but at the concave side of C point canals were enlarged greater than at the convex side(proximal view of K - file: P<0.05, the others: P<0.01). 3. There was no difference m canal enlargement between convex side and concave side in proximal view of A and D points of K - file and K - flex - file(P<0.05). But in clinical view, canal enlargement at convex side of A point and concave side of D point was greater than that at concave side of A point and convex side of D point respectively. 4. Hedstrom - files showed greater canal enlargement at convex side of A points and concave side of D points (P<0.05 or P<0.01). Cavi - Endo showed no difference in canal enlargement between convex side and concave side at A and D points in proximal view(P<0.05). Bur canal enlargement was greater at concave side than at convex side of D point in clinical view. 5. K - file and Cavi - Endo showed no differences in canal enlargement between convex and concave side in proximal and clinical view (P<0.05). K - flex - file showed greater canal enlargement at concave side in proximal and clinical view(P<0.0:5). Hedstrom file showed no difference in canal enlargement between convex side and concave side in proximal view, but showed greater canal enlargement at concave side in clinical view(P<0.05).

• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1135-1142
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• 2008

Collapse of the levee surrounding structure(culvert) accounts for l0 % of collapse factors of the river levees. In particular, in 2002, the levee collapse that happened at "Nakdong River" at flood usually happened around culverts. This levee collapse has mechanism that the cavity expands with internal erosion at flood after the pore and cavity are formed between culvert and levee copula which are heterogeneity material. The study regarding the cavity or flowing detection around a culvert for safety management of a river levee is in the proceeding. In this study, the characteristic of two sensors could be figured out through an experiment about displacement measure of Flex sensor and FBG sensor and the decision of more suitable sensor was possible for safety supervision of river levee. According to an experiment result, several characteristics of FBG sensor could be known in consistency of the measure data and minute displacement measure part regarding displacement measure and this characteristic may supplement a shortcoming of Flex sensor at this time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.49-50
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.569-570
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• 2009

• Advances in aircraft and spacecraft science
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• v.5 no.6
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• pp.653-669
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• 2018

This work has the objective to analyze multibody mechanisms of inflatable structures for manned space applications. The focus is on the evaluation of the main characteristics of MaxFlex, a new module of MSC Adams including the effect of nonlinear flexible bodies. MaxFlex integrates the nonlinear Finite Element Analysis (FEA) of Nastran-SOL400-and the Adams multibody capabilities in one unique solver, providing an improvement concerning the concept and technology based on the co-simulation among solvers. MaxFlex converts the equations of motion of the nonlinear FEA into phase-space form and discretizes them according to the multibody system integrator framework. The numerical results deal with an inflatable manned space module having rigid components and a flexible coating made of Kevlar. This paper is a preliminary assessment of the computational capabilities of the software and does not provide realistic guidelines for the actual design of the structure. The analysis leads to some recommendations related to the main issues to consider in a nonlinear simulation including both rigid and flexible components. The results underline the importance of realistic deployment times and applied forces. Also, a proper structural modeling is necessary, but can lead to excessive computational overheads.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1141-1150
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• 2007

Molecular modeling study has been performed to assist in the design of PTP1B inhibitors using FlexX. FlexX dockings with 19 test ligands, whose structures have been determined by X-ray crystallography, were successful in reproducing the experimental conformations within the protein. An increase in biological activity is observed as hydrophobic character of formylchromone derivatives increases. Most ligands bind to the activesite regions of the protein successfully in two different score runs. The Drug score run gave better results than the FlexX score run based on the score, rank, binding modes and bond distance of docked structures. Consensus values from the CScore scoring function are between 3 and 5, suggesting that the scoring scheme is reliable. All formylchromone inhibitors considered in this work show unidirectional binding modes in the active site pocket, which is contrary to the bidirectional X-ray results by Malamas et al. and amino acid residues responsible for such orientation are identified to help further development of the inhibitors.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.4
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• pp.20-29
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• 2014

This research aims to study the new paradigm of NDE measurement which allows the identification of defect locations and sizes of a certain structure by measuring its surface temperature after applying heat. STS which has a certain defect is applied by the heat of 70000W by a heater. Its difference of STS surface temperature is measured by using Infrared thermography. The estimated result of STS experiment and that of theoretical analysis of Flex-PDE are compared and analyzed to diagnose STS defect. Moreover, this study can save time and money and improve accuracy in contrast to the existing ultrasonic NDE experiment. In addition, the new paradigm of NDT/NDE by reverse-engineering will be valid if the data of thermal analysis and temperature distribution from the specifications of many materials is accumulated and verified.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.87-96
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• 2013

This paper shows how the performance of an ESC(Electronic Stability Control) system can be affected by the selection of in-vehicle network protocols such as CAN or FlexRay. The vehicle control performance under ESC operation is analyzed by EILS(ECU-In-the-Loop Simulation). The experimental set-up for the EILS of the ESC system consists of two 32-bit microcontroller boards communicated with CAN or FlexRay protocols. A 7-DOF vehicle model and an ESC algorithm with 2-DOF reference vehicle model are implemented on each microcontroller respectively. It is shown by experimental results that the ESC system using the FlexRay protocol can achieve better performance than that using the CAN protocol for a fast and accurate lane changing.

• ETRI Journal
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• v.38 no.6
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• pp.1163-1171
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• 2016

Integration technologies involving flexible substrates are receiving significant attention owing the appearance of new products regarding wearable and Internet of Things technologies. There has been a continuous demand from the industry for a reliable bonding method applicable to a low-temperature process and flexible substrates. Up to now, however, an anisotropic conductive film (ACF) has been predominantly used in applications involving flexible substrates; we therefore suggest low-temperature lead-free soldering and bonding processes as a possible alternative for flex-on-flex applications. Test vehicles were designed on polyimide flexible substrates (FPCBs) to measure the contact resistances. Solder bumping was carried out using a solder-on-pad process with Solder Bump Maker based on Sn58Bi for low-temperature applications. In addition, thermocompression bonding of FPCBs was successfully demonstrated within the temperature of $150^{\circ}C$ using a newly developed fluxing underfill material with fluxing and curing capabilities at low temperature. The same FPCBs were bonded using commercially available ACFs in order to compare the joint properties with those of a joint formed using solder and an underfill. Both of the interconnections formed with Sn58Bi and ACF were examined through a contact resistance measurement, an $85^{\circ}C$ and 85% reliability test, and an SEM cross-sectional analysis.

• Progress in Medical Physics
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• v.32 no.4
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• pp.159-164
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• 2021

Purpose: We investigated the properties of CLEANBOLUS based on silicone with suitable characteristics for clinical use. Methods: We evaluated the characteristics of CLEANBOLUS and compared the results with the commercial product (Super-Flex bolus). Also, we conducted physical evaluations, including shore hardness, element composition, and elongation break. Transparency was investigated through the measured absorbance within the visible region (400-700 nm). Also, dosimetric characteristics were investigated with surface dose and beam quality. Finally, the volume of unwanted air gap was investigated based on computed tomography images for breast, chin, and nose using Super-Flex bolus and CELANBOLUS. Results: CLEANBOLUS showed excellent physical properties for a low shore hardness (000-35) and elongation break (>1,000%). Additionally, it was shown that CLEANBOLUS is more transparent than Super-Flex bolus. Dosimetric results obtained through measurement and calculation have an electron density similar to water in CLEANBOLUS. Finally, CLEANBOLUS showed that the volume of unwanted air gap between the phantom and each bolus is smaller than Super-Flex bolus for breast, chin, and nose. Conclusions: The physical properties of CLEANBOLUS, including excellent adhesive strength and lower shore hardness, reduce unwanted air gaps and ensure accurate dose distribution. Therefore, it would be an alternative to other boluses, thus improving clinical use efficiency.