• Journal of Embryo Transfer
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• v.19 no.2
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• pp.133-145
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• 2004

Serum-contain is commoly used for the production of in vitro-derived bovine embryos. However, were biological activity of serum varies from lot to lot, time consuming to choose better serum with good quality and risks of virus, bacteria and mycoplasma infection. This study established serum-free culture systems of in vitro embryo development to efficiently obtain a large number of blastocysts from ovaries of Hanwoo and oocytes maturation, cell number, tlerance of cryopreservation. Secondly, serum-contain medium is suspected of contributing to the large calf size, dystocia, cersarean sections, calf mortality and confirmed these blastocysts are high quality in terms of cyotolerance, high rates of pregancy and normal birth. For these reasons, Culture media (IVMD101 and IVD101) designed specifically for the preimplantation bovine embryo are rather simplistic, being based on salt solutions with additional energy substrates and growth factors. An improved serum-free medium (IVMD101) was developed for bovine oocytes maturation in vitro. Proportions of embryos developing to the blastocyst stage cultured in both IVD101(32.4%) and IVD101(34.5%) serum-free media were higher than in TCM199+10% FBS(12.4%) serumcontaining medium. Futhermore, the cell numbers per blastosyst obtained in the serum-free media were superior to those of blastocysts developed in serum-supplemented medium. Also, cell numbers of blastocysts obtained in the serum-free media were similar with blastocysts derived in vivo. Survival rate blastocysts after 24 hr incubation after thawing, the blastocysts cultured in both IVD101(94.5%) and IVD101(95.8%) serum-free media were higher than in TCM199+10% FBS (52.5%) serum-containing medium. After 72 hr incubation after thawing, hatching rates of blastocysts developed in IVD101(78.4%) and IVMD101(83.7%) were sighnificantly higher than that developed in the serum-supplemented medium(32.0%). The pregnancy rates almost not different between fresh blastocysts(38.2%) and frozen blastocysts(34.9%). The results suggested that the improved serum-free media(IVMD101 and IVD101) offer several advantages over culture in serum-cotaining medium, including increased rates of blastocyst formation and high cel numbers. Additionally, the survival and hatching rates of embryos product in serum-free media after post-thaw culture were superior to those of embryos produced in the serum-containg medium and useful for the production of high quality bovine embryos for cryo-preservation. These improved serum-free media are beneficial not only for the study of the mechanisms of early embryogenesis but also for mass production of good quality embryos for embryo transfer, cloning and transgenesis.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.307-317
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• 2002

In this paper we propose a new mesh reconstruction scheme that produces a displaced subdivision surface directly from unorganized points. The displaced subdivision surface is a new mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface, but original displaced subdivision surface algorithm needs an explicit polygonal mesh since it is not a mesh reconstruction algorithm but a mesh conversion (remeshing) algorithm. The main idea of our approach is that we sample surface detail from unorganized points without any topological information. For this, we predict a virtual triangular face from unorganized points for each sampling ray from a parameteric domain surface. Direct displaced subdivision surface reconstruction from unorganized points has much importance since the output of this algorithm has several important properties: It has compact mesh representation since most vertices can be represented by only a scalar value. Underlying structure of it is piecewise regular so it ran be easily transformed into a multiresolution mesh. Smoothness after mesh deformation is automatically preserved. We avoid time-consuming global energy optimization by employing the input data dependant mesh smoothing, so we can get a good quality displaced subdivision surface quickly.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.249-254
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• 2022

With the rapid advance of the semiconductor and Information and communication technologies, remote environment monitoring technology, which can detect and analyze surrounding environmental conditions with various types of sensors and wireless communication technologies, is also drawing attention. However, since the conventional remote environmental monitoring systems require external power supplies, it causes time and space limitations on comfortable usage. In this study, we proposed the concept of the self-powered remote environmental monitoring system by supplying the power with the levitation-electromagnetic generator (L-EMG), which is rationally designed to effectively harvest biomechanical energy in consideration of the mechanical characteristics of biomechanical energy. In this regard, the proposed L-EMG is designed to effectively respond to the external vibration with the movable center magnet considering the mechanical characteristics of the biomechanical energy, such as relatively low-frequency and high amplitude of vibration. Hence the L-EMG based on the fragile force equilibrium can generate high-quality electrical energy to supply power. Additionally, the environmental detective sensor and wireless transmission module are composed of the micro control unit (MCU) to minimize the required power for electronic device operation by applying the sleep mode, resulting in the extension of operation time. Finally, in order to maximize user convenience, a mobile phone application was built to enable easy monitoring of the surrounding environment. Thus, the proposed concept not only verifies the possibility of establishing the self-powered remote environmental monitoring system using biomechanical energy but further suggests a design guideline.

• Korean Journal of Remote Sensing
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• v.39 no.2
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• pp.193-205
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• 2023

A large amount of floating debris from land-based sources during heavy rainfall has negative social, economic, and environmental impacts, but there is a lack of monitoring systems for floating debris accumulation areas and amounts. With the recent development of artificial intelligence technology, there is a need to quickly and efficiently study large areas of water systems using drone imagery and deep learning-based object detection models. In this study, we acquired various images as well as drone images and trained with You Only Look Once (YOLO)v5s and the recently developed YOLO7 and YOLOv8s to compare the performance of each model to propose an efficient detection technique for land-based floating debris. The qualitative performance evaluation of each model showed that all three models are good at detecting floating debris under normal circumstances, but the YOLOv8s model missed or duplicated objects when the image was overexposed or the water surface was highly reflective of sunlight. The quantitative performance evaluation showed that YOLOv7 had the best performance with a mean Average Precision (intersection over union, IoU 0.5) of 0.940, which was better than YOLOv5s (0.922) and YOLOv8s (0.922). As a result of generating distortion in the color and high-frequency components to compare the performance of models according to data quality, the performance degradation of the YOLOv8s model was the most obvious, and the YOLOv7 model showed the lowest performance degradation. This study confirms that the YOLOv7 model is more robust than the YOLOv5s and YOLOv8s models in detecting land-based floating debris. The deep learning-based floating debris detection technique proposed in this study can identify the spatial distribution of floating debris by category, which can contribute to the planning of future cleanup work.