• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.4
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• pp.364-371
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• 2003

In this paper, a review of the current status, on the use of long range cylindrically guided wave modes, and their interaction with cracks and corrosion damage in pipe-like structures will be discussed. Applications of cylindrically guided ultrasonic wave modes have been developed for inspection of corrosion damage in pipelines at chemical plants, flow-accelerated corrosion damage (wall thinning) in feedwater piping, and circumferential stress corrosion cracks in PWR steam generator tubes. It has been demonstrated that this inspection technique can be employed on a variety of piping geometries (diameters from 1 in. to 3 ft, and wall thickness from 0.1 to 6 in.) and a propagation distance of 100 meters or more is sometimes feasible. This technique can also be used in the inspection of inaccessible or buried regions of pipes and tubes.

• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.83-87
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• 1992

Rencently, angle-resolved ultraviolet photoemission measurements of the Fermi surface contours for Mo(011) and W(011) are reported. The electron contour of W(011) is expanded upon hydrogen adsorption, which implies that the surface states consisting of electron pockets are shifted to higher binding energy. This phenomena can be explained by the band flattening. We explained here the reconstruction of W(011) surface induced by adsorption of hydrogen in terms of band flattening of surface states with a combination of S. E. Trullinger long range dipole-dipole interaction force and Kohn anomaly.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.50-51
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• 2001

We investigate the effect of resonantly excited excitons on the optical-absorption of the n=1hh and n=2hh exciton resonances in GaAs quantum wells. Under quasistationary excitation condition using the pump and probe beam at tow temperature, we report the first observation of long range Coulomb screening by two dimensional exciton-exciton interaction, and discriminate unambiguously exciton bleaching between by long range Coulomb screening and the Pauli exclusion principle. (omitted)

• Genomics & Informatics
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• v.19 no.1
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• pp.3.1-3.12
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• 2021

Functional interpretation of noncoding genetic variants associated with complex human diseases and traits remains a challenge. In an effort to enhance our understanding of common germline variants associated with lung cancer, we categorize regulatory elements based on eight major cell types of human lung tissue. Our results show that 21.68% of lung cancer-associated risk variants are linked to noncoding regulatory elements, nearly half of which are cell type-specific. Integrative analysis of high-resolution long-range chromatin interactome maps and single-cell RNA-sequencing data of lung tumors uncovers number of putative target genes of these variants and functionally relevant cell types, which display a potential biological link to cancer susceptibility. The present study greatly expands the scope of functional annotation of lung cancer-associated genetic risk factors and dictates probable cell types involved in lung carcinogenesis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1191-1195
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• 2007

Many approximate models for interaction between a flexible structure and an infinite external acoustic medium have been developed for a long time. Among them, Doubly Asymptotic Approximations (DAAs) are very well known approximations. But, it has shortcomings in intermediate frequency range and can't fully describe the acoustic medium. So, this paper presents the modified approximation by applying the retarded and advanced potentials to Kirchhoff's formula. It describes the external acoustic medium more in detail and shows a good result in early time transient responses when it was applied to a spherical shell. Through a spherical shell interacting with external acoustic medium, the transient responses for the proposed model is compared to Huang's exact solution and DAA2.

• Journal of Welding and Joining
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• v.14 no.1
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• pp.38-46
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• 1996

High temperature low cycle fatigue crack growth behavior is investigated over a range of two temperatures and various frequencies in SUS 304 stainless steel. It is found that low frequency and temperature can enhance time-dependent crack growth. With high temperature, low frequency and long crack length, ${\Delta}J_c/{\Delta}J_ f$, the ratio of creep J integral range to fatigue J integral range is increased and time-dependent crack growth is accelerated. Interaction between ${\Delta}J_f$ and ${\Delta}J_c$ is occured at high frequency and low temparature and ${\Delta}J_c$, creep J integral range is fracture mechanical parameter on transition from cycle-dependent to time dependent crack growth in creep temperature region.

• Magazine of the Korean Society of Agricultural Engineers
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• v.35 no.3
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• pp.130-139
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• 1993

In order to evaluate the long-term permeability performace of the geotextiles, for five different combination of geotextiles and soils the long-term column test method The results obtained are as follows; 1.The gradient range of the initial stage of the long-term permeability curves varied with respect to the soil types, while that of the final stage varied according to the interaction of the soil/geotextile system. 2.The time required for a given soil/geotextile system to reach a interactive stable stage was measured ahout 100 hours for the standard sand and 150 to 600 hours for the silty content soils, respectively. 3.There were no differences between the plain woven geotextile and the non-geotextile in the long-term permeability performance. 4.As the silt content increased, the long-term performance of the geotextiles decreased, and the limiting silt content was about 15%. 5.The thickness and area density of the geotextiles did not influence on the variation of the seepage quantities. 6.The ayerage slope and the transition time of the long-time flow curve were calculated. 7.In order to evaluate the mechanism of soil/geotextile system more perfectly, the gradient ratio test or the hydraulic conductivity test is required.

• BMB Reports
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• v.45 no.11
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• pp.604-611
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• 2012

Recent advances in genome and transcriptome analysis have enabled identification of numerous members of a new class of noncoding RNA, long noncoding RNA (lncRNA). lncRNAs are broadly defined as RNA molecules greater than 200 nt in length and lacking an open reading frame. Recent studies provide evidence that lncRNAs play central roles in a wide range of cellular processes through interaction with key component proteins in the gene regulatory system, and that alteration of their cell- or tissue-specific expression and/or their primary or secondary structures is thought to promote cell proliferation, invasion and metastasis. The biological and molecular characteristics of the large majority of lncRNAs remains unknown, and it is anticipated that improved understanding of the roles played by lncRNAs in cancer will lead to the development of novel biomarkers and effective therapeutic strategies.

• Structural Engineering and Mechanics
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• v.57 no.3
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• pp.529-541
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• 2016

Under the interaction between dam body, dam foundation and external environment, the dam structural behavior presents the time-varying nonlinear characteristics. According to the prototypical observations, the correct identification on above nonlinear characteristics is very important for dam safety control. It is difficult to implement the description, analysis and diagnosis for dam structural behavior by use of any linear method. Based on the rescaled range analysis approach, the algorithm is proposed to identify and extract the fractal feature on observed dam structural behavior. The displacement behavior of one actual dam is taken as an example. The fractal long-range correlation for observed displacement behavior is analyzed and revealed. The feasibility and validity of the proposed method is verified. It is indicated that the mechanism evidence can be provided for the prediction and diagnosis of dam structural behavior by using the fractal identification method. The proposed approach has a high potential for other similar applications.

• English Language & Literature Teaching
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• v.16 no.3
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• pp.119-139
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• 2010

The purpose of this paper was to examine various aspects of meaning negotiation process in online chatting. Korean college students were asked to engage in chatting on the Internet over the course of a semester-long period, and chatting transcripts were analyzed in terms of sources of communication breakdown, signals to indicate communication breakdown, strategies to overcome communication breakdown, and ways of closing meaning negotiation. According to the findings of the study, lack of background knowledge and incoherent string of sentences in text were two major barriers creating communication problems. Subjects were able to use signals to indicate their communication difficulties, and overcome them by using different strategies. In doing so, however, they were found to suffer a narrow range of signals and strategies, which showed their limited communicative ability in the management of interaction, and indicated a clear, strong need for an extension of discourse and strategic competences of Korean students for more effective and smoother transition of message in everyday interaction.