• Clinical and Experimental Reproductive Medicine
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• v.43 no.1
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• pp.31-37
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• 2016

Objective: The aim of this study was to investigate associations between the morphology score of blastocysts and blastocoele re-expansion speed after warming with clinical outcomes, which could assist in making correct and cost-effective decisions regarding the appropriate time to vitrify blastocysts and to transfer vitrified-warmed blastocysts. Methods: A total of 327 vitrified-warmed two-blastocyst transfer cycles in women 38 years old and younger were included in this retrospective study. Results: The clinical pregnancy rate (CPR) and implantation rate (IR) of transfers of two good-morphology grade 4 blastocysts vitrified on day 5 (64.1% and 46.8%, respectively) were significantly higher than the CPR and IR associated with the transfers of two good-morphology grade 3 blastocysts vitrified on day 5 (46.7% and 32.2%, respectively). No significant differences were found in the CPR and IR among the transfers of two good-morphology grade 4 blastocysts regardless of the day of cryopreservation. Logistic regression analysis showed that blastocoele reexpansion speed after warming was associated with the CPR. Conclusion: The selection of a good-morphology grade 4 blastocyst to be vitrified could be superior to the choice of a grade 3 blastocyst. Extending the culture of grade 3 blastocysts and freezing grade 4 or higher blastocysts on day 6 could lead to a greater likelihood of pregnancy. Since re-expansion was shown to be a morphological marker of superior blastocyst viability, blastocysts that quickly re-expand after warming should be prioritized for transfer.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.903-908
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• 2007

A retractor is the major component of a seatbelt system that restraints passengers by locking the movement of webbing. Recently, in order to increase the effectiveness of seatbelt systems, motorized retractors that remove slack and correct passenger posture just before airbag expansion when collision is predicted are widely used. Key component of motorized retractors is the one-way clutch that engages and disengages the winding action of webbing according to the direction of motor revolution. Analytical investigation of action of the one-way clutch mechanism has been carried out to figure out conditions for one-way locking, and to study the effect of various kinematic and dynamic design variables of one-way clutch. Using combination of ADAMS and LifeMOD soft-wares, dynamic simulation of operation of motorized retractors including Hybrid-III dummy model has been carried out to evaluate the performance of the motorized retractors in various crash scenarios.

• Journal of the Korean Mathematical Society
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• v.49 no.5
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• pp.993-1015
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• 2012

In this paper, we study the quantum sl($n$) representation category using the web space. Specially, we extend sl($n$) web space for $n{\geq}4$ as generalized Temperley-Lieb algebras. As an application of our study, we find that the HOMFLY polynomial $P_n(q)$ specialized to a one variable polynomial can be computed by a linear expansion with respect to a presentation of the quantum representation category of sl($n$). Moreover, we correct the false conjecture [30] given by Chbili, which addresses the relation between some link polynomials of a periodic link and its factor link such as Alexander polynomial ($n=0$) and Jones polynomial ($n=2$) and prove the corrected conjecture not only for HOMFLY polynomial but also for the colored HOMFLY polynomial specialized to a one variable polynomial.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.257-277
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• 2017

This study was conducted to suggest policy implications of providing public function of organic farming. Define the difficulties of rice farmers to provide public utility of organic farming. We estimated the amount of the farmers would like to receive for the practice of organic agriculture using choice experiment methods. By evaluating individual economic values through WTA estimates, its meaningful to grasp farmers preference for organic farming practice and conversion. These results could be used as useful data for future organic agriculture policy. For the expansion of organic farming, it is required to evaluate correct and accurate economic value and reflect this in policy.

• Advanced Composite Materials
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• v.17 no.3
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• pp.301-317
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• 2008

The energy release rate associated with crack growth in adhesive double cantilever beam (DCB) specimens, including the effect of residual stresses, was formulated using beam theory. Because of the rotation of the asymmetric arms in the adhesive DCB specimens due to temperature change, it is necessary to correct the evaluated fracture toughness of the DCB specimens, specifically in the case of a large temperature change. This study shows that the difference between the true toughness and an apparent toughness due to the consequence of ignoring residual stresses can be calculated for a given specimen geometry and thermo-mechanical properties (e.g. coefficient of thermal expansion). The calculated difference in the energy release rates based on the present correction method is compared with that from FEM in order to verify the present correction method. The residual stress effects on the evaluation of the adhesive fracture toughness are discussed.

• Journal of the Optical Society of Korea
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• v.16 no.3
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• pp.228-235
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• 2012

It is very important to analyze effectively the tolerance of an optical system with high resolution as the projection lens of photolithography or as the objective lens of a microscope. We would like to find an effective assembly structure and compensators to correct aberrations through global wavefront sensitivity analysis using Zernike polynomial expansion from the field and pupil coordinates rather than from only pupil coordinates. In this paper, we introduce global wavefront coefficients by small perturbations of the optical system, and analyze the optical performance with these coefficients. From this analysis, it is possible to see how we can enlarge the tolerance through the proper assembly structure and compensators.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.7-16
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• 2019

According to KGS FS551, the safety of an exposure pipe system should be calculated quantitatively by calculating the stress of exposed piping for thermal expansion. However, many pipe system designs and installation sites are not equipped for this. Therefore, KGS FS551 suggested the use of safe gas by presenting the recommended pipe shape. The shapes of various pipe systems have been derived. However, the recommended shape could not be an absolute evaluation standard. Furthermore, the ongoing debate over standards between a plumbing installer and an inspector is an obstacle to the efficient and safe use of gas. Therefore, the correct pipe system evaluation method is examined in this study, and the safety of the existing exposed pipe system is verified.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.39-46
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• 2019

This paper proposes an adaptive threshold watershed algorithm, which is the method used for image segmentation and boundary detection, which extends the region on the basis of regional minimum point. First, apply adaptive thresholds to determine regional minimum points. Second, it extends the region by applying adaptive thresholds based on determined regional minimum points. Traditional watershed algorithms create over-segmentation, resulting in the disadvantages of breaking boundaries between regions. These segmentation results mainly from the boundary of the object, creating an inaccurate region. To solve these problems, this paper applies an improved watershed algorithm applied with adaptive threshold in regional minimum point search and region expansion in order to reduce over-segmentation and breaking the boundary of region. This resulted in over-segmentation suppression and the result of having the boundary of precisely divided regions. The experimental results show that the proposed algorithm can apply adaptive thresholds to reduce the number of segmented regions and see that the segmented boundary parts are correct.

• Archives of Plastic Surgery
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• v.39 no.4
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• pp.333-337
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• 2012

Background Patients who have undergone enucleation during infancy due to retinoblastoma can develop microorbitalism due to the decreased growth stimulation from the eyeball and the surrounding soft tissues. Anatomically, the orbit consist of parts of the frontal bone superiorly, the maxilla inferiorly, the ethmoid bone medially, and the zygoma laterally. Considering the possibility of surgically expanding the orbit using tripod osteotomy, in this study we conducted tripod osteotomy on adult patients with microorbitalism of retinoblastoma. Methods Tripod osteotomy was conducted to expand the orbital volume in adult patients with microorbitalism due to enucleation in infancy for retinoblastoma. The orbital volume was measured using the Aquarius Workstation ver. 4.3.6 and the orbit width was measured with preoperative and postoperative 3-dimensional facial bone computed tomography (CT) imaging. Preoperative and postoperative photographs were used to visualize the difference produced by the surgery. Results The orbital volume of the affected side was 10.3 $cm^3$ before and 12.5 $cm^3$ after the surgery, showing an average increase in volume of 2.2 $cm^3$ (21.4%). The increase in the obital width was confirmed by the preoperative and postoperative 3-dimensional facial CT images and aesthetic improvement was observed by the preoperative and postoperative photographs. Conclusions Tripod osteotomy, which realigns the orbital bone, zygoma, and maxilla, is used to correct posttraumatic malunion as well as non-traumatic congenital abnormalities such as that seen in facial cleft. We applied this procedure in microorbitalism secondary to enucleation for retinoblastoma to allow orbital expansion and correct asymmetry.

• Journal of The Korean Association of Information Education
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• v.23 no.1
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• pp.65-72
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• 2019

As the importance of SW education grows, researches are actively being conducted to improve students' thinking skills. We conducted the group III tasks, which are experiencing and challenging in Beaver Challenge 2018, on 55 students of 5th grade in elementary school. Based on the result, we analyzed their average scores and defined whether each test has a correlation with possession of smartphone, computer familiarity, patience, concentration, and academic ability. The result indicated challenging task boosted the average score, the percentage of correct answers, and the percentage of correct answers for each level of difficulty. Moreover, the challenge task scores were higher as they higher computer familiarity, patience and concentration level. However, possession of smartphones and academic ability did not affect the score. Lastly, the scores were affected by different factors in different level of difficulty that patience factor in advanced level, computer familiarity factor in intermediate level, and concentration factor in beginner level. Thus, further researches are necessary to be conducted to expand the scope of the analysis through the diversification of test subject group and expansion of an evaluation area.