• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.5
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• pp.358-364
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• 1998

Retrograde well is a new process for ULSI fabrication. High energy ion implantation has been used for retrograde well formation. In this paper the forming condition for retrograde well using high energy ion implantation is compared with that for conventional well. TW signals for retrograde p-,n-well($900^{\circ}C$),after annealing are similar trends to those of conventional ones($1150^{\circ}C$), however the signals for RTA have the highest value because of small thermal budget. Junction depths of retrograde well are varied from about 1.2 to $3.0\{mu}m$ as for conventional well. The peak concentrations of retrograde well, however, are about 10 times higher in values than those of conventional ones so that they can be used as any types of potential barriers or gettering sites. The critical dose for phosphorus implantation in our experiments is between $3\times10^{13} and 1\times10^{14}/cm^2$. Under the above critical dose, there are many secondary defects near projected range such as dislocation lines and dislocation loops.

• Archives of Plastic Surgery
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• v.46 no.3
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• pp.255-261
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• 2019

Cross-leg flaps are a useful reconstructive option for complex lower limb defects when free flaps cannot be performed owing to vessel damage. We describe the use of the extended distally based sural artery flap in a cross-leg fashion for lower extremity coverage in three patients. To maximise the viability of these extended flaps, a delay was performed by raising them in a bipedicled fashion before gradual division of the tip over 5 to 7 days for cross-leg transfer. Rigid coupling of the lower limbs with external fixators was critical in preventing flap avulsion and to promote neovascular takeover. The pedicle was gradually divided over the ensuing 7 to 14 days before full flap inset and removal of the external fixators. In all three patients, the flaps survived with no complications and successful coverage of the critical defect was achieved. One patient developed a grade 2 pressure injury on his heel that resolved with conservative dressings. The donor sites and external fixator pin wounds healed well, with no functional morbidity. The cross-leg extended distally based sural artery flap is a reliable reconstructive option in challenging scenarios. Adequate flap delay, manoeuvres to reduce congestion, and postoperative rigid immobilization are key to a successful outcome.

• Structural Monitoring and Maintenance
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• v.10 no.3
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• pp.221-242
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• 2023

Internal and external corrosion are common in pressure pipes used in a variety of industries, often resulting in defects that compromise their integrity. This economically and industrially significant problem calls for both preventive and curative technical solutions to guarantee the reliability of these structures. With this in mind, our study focuses on the influence of composite and metallic patch repairs on the limit loads of pipes, particularly elbows, the critical component of piping systems. To this end, we used the nonlinear extended finite element method (X-FEM) to study elbows, a priori corroded on the internal surface of the extrados section, then repaired with composite and metallic patches. In addition, the effect of the geometry of composite materials and metal patches was examined, in particular the effect of their thickness and material on the increase in limit loads of repaired structures. The results obtained provide information on the effectiveness and optimization of patch repair of corroded elbows, with the aim of increasing their service life.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.65-70
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• 2024

Using a computational fluid dynamics(CFD) simulation tool, we have provided a coating guideline for slot-die coating with a double layer slot die head. We have analyzed the fluid dynamics in terms of the coating speed, flow rate ratio, and viscosity ratio, which are critical for the stability of coating meniscus. We have identified the common coating defects such as break-up, air entrainment, and leakage by varying the coating speeds. The flow rate ratio is the critical parameter determining the wet film thickness of the top and bottom layers. It is shown that when the flow rate ratio exceeds or equals 1.8, air entrainment occurs due to insufficient hydraulic pressure in the bottom layer, even though the total flow rate remains constant. Furthermore, we have found that the flow of the bottom layer is significantly affected by the viscosity of top layer. The viscosity ratio of 4 or higher obstructs the flow of the bottom layer due to the increased hydraulic resistance, resulting in leakage. Finally, we have demonstrated that as the viscosity ratio increases from 0.1 to 10, the maximum coating speed rises from 0.4 mm/s to 1.6 mm/s, and the minimum wet film thickness decreases from 800 ㎛ to 200 ㎛.

• Journal of Life Science
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• v.21 no.5
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• pp.621-626
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• 2011

AMP-activated protein kinase (AMPK), a heterotrimeric complex comprising a catalytic ${\alpha}$ subunit and regulatory ${\beta}$ and ${\gamma}$ subunits, has been primarily studied as a major metabolic regulator in various organisms, but recent genetic studies discover its novel physiological functions. The first animal model with no functional AMPK ${\gamma}$ subunit gene was generated by using Drosophila genetics. AMPK ${\gamma}$ flies demonstrated lethality with severe defects in cuticle formation. Further histological analysis found that deletion of AMPK ${\gamma}$ causes severe defects in cell polarity in embryo epithelia. The phosphorylation of nonmuscle myosin regulatory light chain (MRLC), a critical regulator of epithelial cell polarity, was also diminished in AMPK ${\gamma}$ embryo epithelia. These defects in AMPK ${\gamma}$ mutant epithelia were successfully restored by over-expression of AMPK ${\gamma}$. Collectively, these results suggested that AMPK ${\gamma}$ is a critical cell polarity regulator in metazoan development.

• Journal of KIISE
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• v.44 no.9
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• pp.893-907
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• 2017

In safety-critical systems, software defects may have serious consequences. Therefore, defects should be considered during the requirements specification process, which is the first step of a software development lifecycle. Stakeholder requirements that are usually written in natural language are difficult to derived, and there may also be defects due to ambiguity and inaccuracy. To address these issues, we propose a requirement specification method using a standardized Boilerplate and a GSN Model. The Boilerplate is a semi-standard language that follows a predefined format. Due to its ability to provide a consistent representation of the requirements, boilerplate helps stakeholders avoid ambiguities about what they mean and to define the exact meaning of the requirement. Meanwhile, GSN is recognized notation to prepare a Safety Case to prove to authorities that a system is safe. It can be expressed as a functional goal, e.g., Safety Evidence, etc. The proposed study allows an analyst to easily identify a fault from the early stage of the software development lifecycle. The Boilerplate and GSN Model are designed to specify the requirements of safety critical systems and to prove safety conformity through a connection with Safety Evidence. In addition, the proposed approach is also useful to develop secure software by correcting deficiencies in the requirements found during this process.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.1
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• pp.51-56
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• 1989

This study was performed to investigate the effect of defect on fatigue strength under the stress of rotary bending. The specimens were made of low carbon steel having artificial microholes, namely, single micro-hole and two adjacent micro-holes as natural defects, and the effects of the diameter of hole and the distance between the holes on fatigue strength have been investigated. The obtained result can be summarized as follows: 1, The critical defect means the largest size of defect that does not affect fatigue limit, and correspondes to the size of defect leading to final fracture under fatigue limit of smooth specimen. The size of defect which has an effect on fatigue limit is larger than that of critical defect. 2, The defect larger than the critical defect affects fatigue strength for as a kind of size effect, and the physical meaning of size effect of defect is considered same as the one of notch effect.

• Journal of Korea Foundry Society
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• v.18 no.6
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• pp.555-562
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• 1998

Modified fluid critical solid fraction method was utilized as a prediction parameter to describe the shrinkage formation including the position, shape and amount of shrinkage cavities. A numerical scheme was implemented adapting this method for the evaluation of solidification defects in various casting processes. In the present numerical code, the form of shrinkage cavity can be simultaneously determined when an isolated loop is predicted to occur by the fluid critical solid fraction method. An auxiliary parameter, shrinkage potential, was also used in order to calculate the amount of residual liquid during solidification. Solidification analysis was carried out for the validation of the present scheme. It was shown that the calculated results were in good agreement with those of practical casting runs in all of the casting processes envolved in the present research. It may be concluded that the present program successfully predicts the detailed shrinkage formation behavior without the consideration of interdendritic fluid flow analysis.

• Progress in Superconductivity and Cryogenics
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• v.21 no.3
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• pp.18-21
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• 2019

We studied the effect of Fe ion irradiation on the upper critical field ($H_{c2}$) of 410 nm single-crystalline $MgB_2$ thin films. The irradiation energy was fixed at 140 keV when we increased the irradiation doses from $1{\times}10^{14}ion/cm^2$ to $4{\times}10^{14}ion/cm^2$. We found that $H_{c2}$ significantly increase with increasing irradiation dose, despite the low irradiation energy. The enhancement of $H_{c2}$ could be explained by the reduction of electron mean free path caused by defects induced from irradiation, leading to a decrease of coherence length (${\xi}$). We also discussed the effect of irradiation on temperature-dependent resistivity in details.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.100-107
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• 2010

Introduction: A cyst is a closed pathologic sac containing fluid or semi-solid material in central region. The most common conventional treatment for a cyst is enucleation. It was reported that spontaneous bone healing could be accomplished without bone grafting. We are trying to evaluate bone reconstruction ability by analyzing panorama radiograph and computed tomography (CT) scan with retrograde studying after cyst enucleation. In this way we are estimating critical size defect for spontaneous healing without bone graft. Materials and Methods: The study comprised of 45 patients who were diagnosed as cysts and implemented enucleation treatment without bone graft. After radiograph photo taking ante and post surgery for 6, 12, 18, 24 months, the healing surface and volumetric changes were calculated. Results: 1. Spontaneous bone healing was accomplished clinically satisfying 12 months later after surgery. But analyzing CT scan, defect volume changes indicate 79.24% which imply incomplete bone healing of defect area. 2. Comparing volume changes of defect area of CT scan, there are statistical significance between under $5,000mm^{3}$ and over $5,000mm^{3}$. The defect volume of $5,000mm^{3}$ shows $2.79{\times}1.91$cm in panoramic view. Conclusion: Bone defects, which are determined by a healed section using a panoramic view, compared to CT scans which do not show up. Also we can estimate the critical size of defects for complete healing.