• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.4
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• pp.331-340
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• 2004

Deployment of an advanced on-line monitoring of the component integrity offers a prospect of improved performance, enhanced safety, and reduced overall cost for nuclear power plants. Ultrasonic guided waves have been known as one of the promising techniques that could be utilized for on-line monitoring. The present work is aimed at developing a new method for on-line monitoring of the pipes during the operation period of nuclear power plants. For this purpose, the steam generator (S/G) tube was selected as an object of tile experiment. Dispersion corves and the incident angles corresponding to the specific modes were calculated for the S/G tube. The modes of guided waves were identified by the time-frequency diagrams obtained by the short time Fourier transform. It was experimentally confirmed that there was no mode conversion when the ultrasonic guided waves passed over the curved region of the S/G tube. An optimum mode of guided wave for the S/G tube was suggested and verified by the experiment.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.249-259
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• 2018

Radiation technology (RT) has long been applied in various fields for increasing the safety and shelf-life of foods by controlling pathogen-induced poisoning. RT was introduced for the first time in Korea in the 1950s to eliminate harmful microorganisms in food materials. In the 1980s, RT had been scientifically proven to be effective for the sterilization of food and public health products. In recent years, irradiation with gamma rays has also been used for improving physiological properties through the structural modification of natural molecules, which has been proposed to be applicable to various industries. In particular, radiation transformation technology (RTT), which involves the development of new functional compounds through the molecular conversion of natural biomaterials, is becoming a new high-value technology as a fusion technique of RT and biotechnology. The present reports have suggested that RTT can be an effective tool for the development of new functional compounds and improvement of the physiological activity of biomolecules.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.19-24
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• 2021

This paper presents a method to generate three-dimensional AR/VR models using the information in Isogen data files (IDFs). An IDF is an output file produced by ISOGEN that contains piping isometric drawings. A piping isometric drawing is used for pipeline installation in the shipyard; therefore, the drawing describes assembly information with symbolic features, not with detailed geometric features. An IDF specifies relationships between piping routes and components with three-dimensional points and tag information as well as the bill of the materials of a pipeline. The key idea of this paper is that AR/VR models can be generated with the piping route points data and piping components tag information in real time, without any conversion of standard data exchange file formats, such as STP, IGES, and SAT. This paper describes IDF data structure and suggests the geometry generation process with IDF data and parametric functions.

• Journal of Microbiology and Biotechnology
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• v.33 no.3
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• pp.387-397
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• 2023

Cytochrome P450 (CYP) is a heme-containing enzyme that catalyzes hydroxylation reactions with various substrate molecules. Steroid hydroxylases are particularly useful for effectively introducing hydroxyl groups into a wide range of steroids in the pharmaceutical industry. This study reports a newly identified CYP steroid hydroxylase (BaCYP106A6) from the bacterium Bacillus sp. and characterizes it using an in vitro enzyme assay and structural investigation. Bioconversion assays indicated that BaCYP106A1 catalyzes the hydroxylation of progesterone and androstenedione, whereas no or low conversion was observed with 11β-hydroxysteroids such as cortisol, corticosterone, dexamethasone, and prednisolone. In addition, the crystal structure of BaCYP106A6 was determined at a resolution of 2.8 Å to investigate the configuration of the substrate-binding site and understand substrate preference. This structural characterization and comparison with other bacterial steroid hydroxylase CYPs allowed us to identify a unique Arg295 residue that may serve as the key residue for substrate specificity and regioselectivity in BaCYP106A6. This observation provides valuable background for further protein engineering to design commercially useful CYP steroid hydroxylases with different substrate specificities.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.147-154
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• 2023

In the case of river facilities, the management of this information differs depending on national and regional rivers, therefore, there is no integrated management in place. There is concern about the loss of facility information owing to the insufficient accumulation of information during their design and construction stages. Additionally, as a result, the utilization level of facility information during the maintenance and operation stages is insufficient. To ensure effective maintenance and operation of river facilities, it is necessary to secure data consistency and increase efficiency by organizing facility information according to a standardized classification system. This study proposes a strategy for implementing the BIM standard classification system in the river sector, considering facility characteristics. The goal is to introduce a BIM information model for 3D-based river facilities, and enable efficient maintenance and operation conversion.

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.3
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• pp.161-170
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• 2012

This paper presents an efficient and robust approach for determining the correspondence between unbalanced stereo images. The disparity vectors were used instead of feature points, such as corners, to calculate a correspondence relationship. For a faster and optimal estimation, the vectors were classified into several regions, and the homography of each region was calculated using the RANSAC algorithm. The correspondence image was calculated from the images transformed by each homography. Although it provided good results under normal conditions, it was difficult to obtain reliable results in an unbalanced stereo pair. Therefore, a balancing method is also proposed to minimize the unbalance effects using the histogram specification and structural similarity index. The experimental results showed that the proposed approach outperformed the baseline algorithms with respect to the speed and peak-signal-to-noise ratio. This work can be applied to practical fields including 3D depth map acquisition, fast stereo coding, 2D-to-3D conversion, etc.

• Solar Energy
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• v.10 no.3
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• pp.46-52
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• 1990

Novel a-Si solar cells with delta-doped(${\delta}x$-doped) P-layer have been fabricated to enhance the hole concentration of the P-layers. The ${\delta}-$doped P-layer consists of very thin B sheets of 0.1-0.5 atomic layers and undoped a-SiC multi-layers. B-layers were prepared by photo-CVD and pyrolysis technique. The structural, optical and electrical characteristics of the delta-doped P-layer films were evaluated by means of FTIR, AES and SIMS. As the results of this study, it was found that the ${\delta}$-doped P-layer showed much superior optical and electrical characteristics than those of conventional uniformly B-doped a-Si layers. 12.5% energy conversion efficiency was achieved for the Cell with ${\delta}$-doped P-layer.

• Korean Institute of Interior Design Journal
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• no.16
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• pp.135-141
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• 1998

The objective of this study is to examine the specific progress in modern architecture with a premise that structure-oriented paradigm, as a primary factor, exerts a strong impacts on 18th and 19th centuries architecture. For this purpose, the concept and meaning backgrounds of structure-oriented paradigm have been checked also intrinsic thought s and critical aspects of modern architecture with the light of structure-oriented paradigm have been studied, This study summarized as follows: 1) The concept of structure-oriented paradigm in accordance with ideologies and technologies is framework of through which is shared as collective consciousness. 2) The backdrops of this consciousness are scientific methodologies stemmed from Renaissance and Enlightenment spiritual absoluteness claimed by German Idealists developed structural engineering with newly introduced material like iron steel and reinforced concrete. 3) The intrinsic through in architectural theories are rational and technological idelolgies which is derived from the backdrops of structure-oriented paradigm. 4)The critical sapects of modern architecture in structure-oriented paradigm point of view are $\circled1$ material alteration and directive imitation of vocabularies in classical architecture with simply using newly introduced building material and structure systems $\circled2$ morphological substitution with abstractly interpreted materials and structure systems $\circled3$ revolutionary conversion into engineering architecture through maximum consideration in compliance with tectonics capabilities

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1712-1714
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• 2004

During the last 20 years organic semiconductors have attracted considerable attention due to their interesting physical properties followed by various technological applications in the area of electronics and opto-electronics. It has been a long time since organic solar cells were expected as a low-cost energy-conversion device. Although practical use of them has not been achieved, technological progress continues. Morphology of the materials, organic/inorganic interface, metal cathodes, molecular packing and structural properties of the donor and acceptor layers are essential for photovoltaic response. We have fabricated solar cell devices based on zinc-phthalocyanine(ZnPc) as donor(D) and fullerine($C_{60}$) as electron acceptor(A) with doped charge transport layers, $Alq_3$ as an electron transport or injection layer. We observed the photovoltaic characteristics of the solar cell devices using the Xe lamp as a light source.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.608-619
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• 1998

The small and the large intestine of swine represent the organs that extract nutrients from feedstuffs through digestion and fermentation and that allow their absorption and incorporation into the blood circulation. Special attention is directed towards the small intestine of young pigs since the transition to a solid diet at weaning exerts major impacts on the structural and functional integrity of the small intestine. Dietary factors involved in postweaning changes of gut morphology and biochemistry such as removal of bioactive compounds in sows milk at weaning, anti-nutritional factors in weaner diets, dietary fiber and the role of voluntary feed intake will be elucidated. The microbial function of the large intestine which is carried out by a diverse population of microorganisms is dependent on substrate availability. Short chain fatty acids as main fermentation products contribute to the energy supply of the host but they are also important for the maintenance of the morphological and functional integrity of the epithelium in the colon. As a result of bacterial nitrogen assimilation in the large intestine, nitrogen is shifted from the urinary to the fecal excretion route thus saving metabolic energy to the pig because less ammonia would become available for conversion to urea.