• Clinical and Experimental Reproductive Medicine
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• v.49 no.4
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• pp.225-238
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• 2022

The ultimate goal of human assisted reproductive technology is to achieve a healthy pregnancy and birth, ideally from the selection and transfer of a single competent embryo. Recently, techniques for efficiently evaluating the state and quality of preimplantation embryos using time-lapse imaging systems have been applied. Artificial intelligence programs based on deep learning technology and big data analysis of time-lapse monitoring system during in vitro culture of preimplantation embryos have also been rapidly developed. In addition, several molecular markers of the secretome have been successfully analyzed in spent embryo culture media, which could easily be obtained during in vitro embryo culture. It is also possible to analyze small amounts of cell-free nucleic acids, mitochondrial nucleic acids, miRNA, and long non-coding RNA derived from embryos using real-time polymerase chain reaction (PCR) or digital PCR, as well as next-generation sequencing. Various efforts are being made to use non-invasive evaluation of embryo quality (NiEEQ) to select the embryo with the best developmental competence. However, each NiEEQ method has some limitations that should be evaluated case by case. Therefore, an integrated analysis strategy fusing several NiEEQ methods should be urgently developed and confirmed by proper clinical trials.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.313-316
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• 2007

Ground-penetrating radar (GPR) is an effectiveness tool for imaging spatial distribution of hydrogeologic parameters. An artificial groundwater recharge test has been conducted in Nagaoka City in Japan, and time-lapse crosshole GPR data were collected to monitor infiltration processes in a vadose zone. Since radiowave velocities in a vadose zone are largely controlled by variations in water content, the increase in traveltimes is interpreted as an increase in saturation in the test zone. We use a finite-difference time-domain method in two-dimensional cylindrical coordinates to simulate field results. Numerical modeling successfully reproduces the major feature of velocity changes in the filtration process.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.174-183
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• 2021

Objective: The aim of this study was to compare the pregnancy outcomes of in vitro fertilization with embryo transfer between embryos cultured in a time-lapse monitoring system (TLS) and those cultured in a conventional incubator (CI). Methods: The medical records of 250 fertilized embryos from 141 patients undergoing infertility treatment with assisted reproductive technology at a tertiary hospital from June 2018 to May 2020 were reviewed. The study population was divided into TLS and CI groups at a 1 to 1 ratio (125 embryos per group). The primary outcome was the live birth rate. Results: The TLS group had a significantly higher clinical pregnancy rate (46.4% vs. 27.2%, p=0.002), implantation rate (27.1% vs. 12.0%, p=0.004), and live birth rate (32.0% vs. 18.4%, p=0.013) than the CI group. Furthermore, subgroup analyses of the clinical pregnancy rate and live birth rate in the different age groups favored the TLS group. However, this difference only reached statistical significance in the live birth rate in women aged over 40 years and the clinical pregnancy rate in women aged 35-40 years (p=0.048 and p=0.031, respectively). The miscarriage rate, cleavage rate, and blastocyst rate were comparable. Conclusion: TLS application improved the live birth rate, implantation rate, and clinical pregnancy rate, particularly in the advanced age group in this study, while the other reproductive outcomes were comparable. Large randomized controlled trials are needed to further explore the ramifications of these findings, especially in different age groups.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.12a
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• pp.15-25
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• 2007

Gravity method could be one of the most effective tool for evaluating the soundness of basement which is directly correlated with density and its variations. Moreover, Gravimeter is easy to handle and strong to electromagnetic noises. But, gravity anomaly due to the target structures in engineering and environmemtal applications are too small to detect, comparing to the external changes, such as, elevation, topography, and regional geological variations. Gravity method targeting these kinds of small anomaly sources with high precision usually called microgravity. Microgravimetry with precision and accuracy of few ${\mu}Gal$, can be achieved by the recent high-resolution gravimeter, careful field acquisition, and sophisticated processing, analysis, and interpretation routines. This paper describes the application of the microgravity, such as, density structure of a rock fill dam, detection of abandoned mine-shaft, detection and mapping of karstic cavities in limestone terrains, and time-lapse gravity for grout monitoring. The case studies show how the gravity anomalies detect the location of the targets and reveal the geologic structure by mapping density distributions and their variations.

• Geophysics and Geophysical Exploration
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• v.8 no.4
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• pp.280-286
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• 2005

Geological sequestration of carbon dioxide ($CO_2$) is one of the most effective strategies far long-term removal of greenhouse gas from atmosphere. This paper reviews three projects for the $CO_2$ sequestration in geological formation. A unique $CO_2$ injection into a marine aquifer has been successfully monitored with repeated surface seismic measurements in the North Sea Sleipner West field. The seismic images reveal the extent and internal shape of the $CO_2$ bubble. Massive miscible $CO_2$ has been injected into a complex fractured carbonate reservoir at the Weyburn oil filed. High-resolution time-lapse P-wave data were successfully obtained to map the features of $CO_2$ movements within the two thin zones of different lithology. From the time-lapse crosswell EM imaging at the Lost Hills oil field in central California, U.S.A., the replacement of brine with $CO_2$ has been confirmed through a decrease of conductivity. The conductivity image was successfully compared with induction logs observed in the two wells.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.94-96
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• 2004

In order to observe the thermal behavior of oil immersed power transformers the temperature rise prediction algorithm and monitoring system were developed. The algorithm is formulated into a computer program based on the TNM (Thermal Network Method) which was divided into several elements, and the temperature of each element was calculated according to each time lapse. A monitoring system can show the real time active part temperatures of the transformer under various electric loads and for any types of thermal environment.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1042-1047
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• 2005

A web-based camera (webcam) is expected to enhance construction operation monitoring. However, webcams are often installed outside a building because their mobility is limited by cable wiring, which makes it difficult to monitor construction operations inside the building. If a webcam is integrated with emerging wireless communication technologies, construction professionals may be able to monitor interior construction operations using webcams without getting network cables wired on a congested and dynamic construction job site. However, one may concern that wireless communication may not be fast enough to transport all webcam images seamlessly. This paper presents an investigation as to the observation error of webcam images when a limited amount of images are delivered.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.252-259
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• 2017

Nowadays, the existing manual method for recording actual progress of the construction site has some drawbacks, such as great reliance on the experience of professional engineers, work-intensive, time consuming and error prone. A method integrating computer vision and BIM(Building Information Modeling) is presented for indoor automatic progress monitoring. The developed method can accurately calculate the engineering quantity of target component in the time-lapse images. Firstly, sample images of on-site target are collected for training the classifier. After the construction images are identified by edge detection and classifier, a voting algorithm based on mathematical geometry and vector operation will divide the target contour. Then, according to the camera calibration principle, the image pixel coordinates are conversed into the real world Coordinate and the real coordinates would be corrected with the help of the geometric information in BIM model. Finally, the actual engineering quantity is calculated.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.12a
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• pp.31-42
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• 2007

Dc resistivity monitoring has been increasingly used in order to understand the changes of subsurface conditions in terms of conductivity. The commonly adopted interpretation approach which separately inverts time-lapse data may generate inversion artifacts due to measurement error. Eventually the contaminated error amplifies the artifacts when reconstructing the difference images to quantitatively estimate the change of ground condition. In order to alleviate the problems, we defined the subsurface structure as four dimensional (4-D) space-time model and developed 4-D inversion algorithm which can calculate the reasonable subsurface structure continuously changing in time even when the material properties change during data measurements. In this paper, we discussed two case histories of resistivity monitoring to study the ground condition change when the properties of the subsurface material were artificially altered by injecting conductive materials into the ground: (1) dye tracer experiment to study the applicability of electrical resistivity tomography to monitoring of water movement in soil profile and (2) the evaluation of cement grouting performed to reinforce the ground. Through these two case histories, we demonstrated that the 4-D resistivity imaging technique is very powerful to precisely delineate the change of ground condition. Particularly owing to the 4-D inversion algorithm, we were able to reconstruct the history of the change of subsurface material property.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.173-178
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• 2007

Time-lapse electrical resistivity measurements have been made in a scale model experiment for geological $CO_2$ sequestration in aquifer. Three types of $CO_2$ injection are tested in a water tank filled with glass beads. These are $CO_2$ dissolved into filtered tap water, $CO_2$ gas, and mineral oil. The mineral oil is a substitute for liquid phase of supercritical $CO_2$. For reconstructing three-dimensional resistivity images, we measure potential differences at 32 potential dipoles on the top surface of the tank due to two current dipoles on the front and back sides. The resultant resistivity images clearly show the movement of injected $CO_2$ in aquifer.