• Journal of the Society of Naval Architects of Korea
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• v.53 no.5
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• pp.380-387
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• 2016

Present research target to develop the procedure of long-term fatigue analysis of the structural details near the upper rolling chock of IMO type B tank by using the time domain modal analysis technique where both the contact and friction behavior can be accurately simulated. In order to perform the time domain analysis focused on the contact and friction, the entire model of the hull and tank was condensed with DOF reduction technique, which is obtained by transforming the global finite element model into its quasi-static modal coordinate. Modal analysis using the quasi-static deformation modes is chosen as a cost effective time domain simulation method and this is based on the fact that the structural response of the tank is quasi-static. Based on the developed cost effective time domain simulation method, the long-term fatigue analysis procedure for the structural details near the rolling chock and key of independent type tank is targeted to be established. The developed fatigue assessment procedure takes into account, wave induced stress and both contact and friction induced stress without loss of accuracy.

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.7-15
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• 2015

This paper attempts to evaluate the accuracy and efficiency of a design optimization procedure by combining wavelets-based multi resolution analysis method and proper orthogonal decomposition (POD) technique. Aerodynamic design procedure calls for high fidelity computational fluid dynamic (CFD) simulations and the consideration of large number of flow conditions and design constraints. Thus, even with significant computing power advancement, current level of integrated design process requires substantial computing time and resources. POD reduces the degree of freedom of full system by conducting singular value decomposition for various field simulations. In this research, POD combined Design Optimization model is proposed and its efficiency and accuracy are to be evaluated. For additional efficiency improvement of the procedure, multi resolution analysis method is also being employed during snapshot constructions (POD training period). The proposed design procedure was applied to the optimization of wing aerodynamic performance. Throughout the research, it was confirmed that the POD/MRA design procedure could significantly reduce the total design turnaround time and also capture all detailed complex flow features as in full order analysis.

• Journal of Chest Surgery
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• v.50 no.3
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• pp.163-170
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• 2017

Background: The absence of atrial contraction (AC) after the maze procedure has been reported to cause subsequent annular dilatation and to increase the risk of embolic stroke. We hypothesized that the lack of AC could increase the risk of permanent pacemaker (PPM) implantation in patients undergoing the maze procedure. Methods: In 376 consecutive patients who had undergone a cryo-maze procedure and combined valve operation, recovery of AC was assessed at baseline and at immediate (${\leq}2$ weeks), early (${\leq}1$ year, $4.6{\pm}3.8$ months), and late (>1 year, $3.5{\pm}1.1$ years) postoperative stages. Results: With a median follow-up of 53 months, 10 patients underwent PPM implantation. Seven PPM implants were for sinus node dysfunction (pauses of $9.6{\pm}2.4$ seconds), one was for marked sinus bradycardia, and two were for advanced/complete atrioventricular block. The median (interquartile range) time to PPM implantation was 13.8 (0.5-68.2) months. Our time-varying covariate Cox models showed that the absence of AC was a risk factor for PPM implantation (hazard ratio, 11.92; 95% confidence interval, 2.52 to 56.45; p=0.002). Conclusion: The absence of AC may be associated with a subsequent risk of PPM implantation.

• Restorative Dentistry and Endodontics
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• v.26 no.5
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• pp.393-398
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• 2001

Polymerization of light-activated restorations results in temperature increase caused by both the exothermic reaction process and the energy absorbed during irradiation. Within composite resin, temperature increases up to 2$0^{\circ}C$ or more during polymerization. But, insulation of hard tissue of tooth lowers this temperature increase in pulp. However, many clinicians are concerned about intrapulpal temperature injury. The purpose of this study was to evaluate temperature changes in the pulp according to various restorative materials and bases during curing procedure. Caries and restoration-free mandibular molars extracted within three months were prepared Class I cavity of 3$\times$6mm with high speed handpiece fissure bur. 1mm depth of dentin was evaluated with micrometer in mesial and distal pulp horns. Pulp chambers were filled with 37.0$\pm$0.1$^{\circ}C$ water to CEJ. Chromium-alumina thermocouple was placed in pulp horn below restorative materials for evaluating of temperature changes. This thermocouple was connected to temperature-recording device(Multiplication analyzer MX, 6.000, JAPAN). Temperature changes was evaluated from initial 37.$0^{\circ}C$ after temperature changes to 37.$0^{\circ}C$. Tip of curing unit was placed in the center of prepared cavity separated 1mm from restorative materials. Curing time was 40s. The restorative materials were used with Z 100, Fuji II LC, Compoglass flow and bases were used with Vitrebond, Dycal. Resrorative materials were placed in 2mm. The depth of bases were formed in 1mm and in this upper portion, resin of 2mm depth was placed. This procedure was performed 10 times. The results were as follows. 1. All the groups showed that the temperature in pulp increased as curing time increased 2. The temperature increase of glass ionomer was significantly higher than that of Resin and Compomer during curing procedure (P<0.05). 3. The temperature increase in glass ionomer base was significantly higher than that of Calcium hydroxide base during Resin curing procedure (P<0.05).

• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.259-269
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• 2020

With the proposal-agreement procedure, RSTP can reduce the network recovery time to 400 ms or less in the case of 40 bridges. While the legacy RSTP reverts the previous agreement at the bridge with the alternate port role in the ring during the fault recovery, a new position based fast fault recovery procedure is proposed in this paper to guarantee a single proposal-agreement transaction which can provide more faster recovery. By knowing the relative position of the faulty link or bridge in hops, the bridge on the middle of the ring can complete the recovery procedure without revert. The performance of proposed procedure is numerically calculated and verified by simulation and the result shows that the recovery time can be reduced up to 100 ms, which is 1/4 times of the legacy RSTP.

• Journal of Korean Foot and Ankle Society
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• v.23 no.2
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• pp.52-57
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• 2019

Purpose: An ingrown nail is common in military trainees who are exposed to highly demanding activities. Although the matrixectomy procedure has been the main treatment modality, several drawbacks may follow after the procedure, such as infection, periostitis, and continued pain that causes a delayed return to duty. This study examined the outcomes of a simple partial nail extraction with the hypothesis that this procedure may bring an earlier return to duty, lower the perioperative complications, and produce a comparable recurrence rate. Materials and Methods: The medical records of patients who had surgical treatment for an ingrown nail in the authors' institution between April 2016 and December 2017 were reviewed retrospectively. Under the inclusion and exclusion criteria, 28 patients with a simple partial nail extraction (group A) and 29 patients with a partial nail extraction with matrixectomy (group B) were investigated. As the clinical outcome, the visual analogue scale (VAS) and satisfaction score, time to return to duty, complications, and recurrence rate were checked and compared between the groups. Results: The VAS scores of group B were significantly higher during the first (p<0.001) and second (p=0.026) follow-up week than group A. The time to return to duty was shorter in group A (7.8 days) than group B (10.1 days), and this difference was significant (p<0.001). Group B had five patients with complications, whereas group A had none (p=0.028). No differences in the recurrence rate (p=0.197) and patient satisfaction (p=0.764) were found between the groups. Conclusion: In this study, simple partial nail extraction in military trainees resulted in lower postoperative pain, lower complication rates, and earlier return to duty than the procedure with matrixectomy. Military trainees are temporarily exposed to highly demanding activities. Thus, a satisfactory outcome would be expected with simple partial nail extraction without performing a radical procedure, such as a matrixectomy.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.96-96
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• 1999

• IE interfaces
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• v.4 no.1
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• pp.47-61
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• 1991

This paper develops MRP system with two-types of lead time(average lead time and emergent lead time). In this proposed MRP system, Material Requirement Planning is scheduled by using average lead time, but the emergent lead time is used only when start date of planned order is past. Btrieve data management technique and Stack structure are used for recalculating procedure of planned order with the TURBO PASCAL Version 5.5. An example is also considered.

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1281-1285
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• 1997

The time-dependent tracking inversion method is developed to extract the potential of the excited state from frequency-domain measurements, such as the absorption profile. Based on the relay of the regularized inversion procedure and time-dependent wave-packet propagation, the algorithm extract the underlying potential piece by piece by tracking the time-dependent data which can be synthesized from frequency-domain measurements. We have demonstrated the algorithm to extract the potential of excited state for a model diatomic molecule. Finally, we describe the merits of the time-dependent tracking inversion method compared to the time-dependent inversion and discuss several extensions of the algorithm.

• Journal of Chest Surgery
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• v.45 no.5
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• pp.308-315
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• 2012

Background: Long-term surveillance comparing satisfaction between the early experience of Nuss procedure vs. Ravitch procedure. Materials and Methods: A total of 100 patients that underwent surgical correction of a pectus excavatum between 2001 and 2004 and were followed for ${\geq}2$ years were included. Surveillance on the degree of satisfaction was performed using five-levels of the Likert scale and self-assessment scoring. Results: Nuss or Ravitch surgery was performed in 63 and 37 patients, respectively. The Nuss procedure required a shorter operation time and shorter hospital stay than the Ravitch procedure (p<0.001). The surveillance demonstrated that 17.6% of the Nuss group and 35.7% of the Ravitch group were not satisfied with the outcome of the surgery (p=0.072). The most common causes of dissatisfaction were redepression in the Nuss group (n=5) and incomplete correction in the Ravitch group (n=7). The multivariate analysis showed that reoperation and a high postoperative pectus index were significant risk factors for a low satisfaction score. Conclusion: The Nuss procedure had several advantages over the Ravitch procedure in the immediate postoperative period. However, the long-term satisfaction was determined by a complete correction without recurrence or need for re-intervention rather than by the operation type.