• Geomechanics and Engineering
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• v.17 no.6
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• pp.507-513
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• 2019

Reinforced soil and Expanded Polystyrenes (EPS) mixture (RSEM) is a geomaterial which has many merits, such as light weight, wide strength range, easy for construction, and economic feasibility. It has been widely applied to improve soft ground, solve bridge head jump, fill cavity in pipeline and widen highway. Reutilizing dredged sediment to produce RSEM as earthfill can not only consume a large amount of waste sediment but also significantly reduce the construction cost. Therefore, there is an urgent need understand the basic stress-strain characteristics of reinforced dredged sediment-EPS mixture (RDSEM). A series of cyclic triaxial tests were then carried out on the RDSEM and control clay. The effects of cement content, EPS beads content and confining pressure on the cyclic stress-strain behaviour of RDSEM were analyzed. It is found that the three stages of dynamic stress-strain relationship of ordinary soil, vibration compaction stage, vibration shear stage and vibration failure stage are also applicative for RDSEM. The cyclic stress-strain curves of RDSEM are lower than that of control clay in the vibration compaction stage because of its high moisture content. The slopes of backbone curves of RDSEMs in the vibration shear stage are larger than that of control clay, indicating that the existence of EPS beads provides plastic resistance. With the increase of cement content, the cyclic stress-strain relationship tends to be steeper. Increasing cement content and confining pressure could improve the cyclic strength and cyclic stiffness of RDSEM.

• Journal of the Korean Institute of Gas
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• v.23 no.2
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• pp.28-34
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• 2019

A large number of underground pipelines in the Ulsan National Industrial Complex has been constructed to improve the productivity of chemical products and tackle transportation problems. Now, the total of 1,293km of underground pipelines around 62 companies has been installed and operated. Many of underground pipelines have been installed outside of factories. For a past three years, five gas leakage accidents have occurred and the emergency response took up to 8 hours or more. Due to these delay in accidents, second serious accidents might occur and lead to occur damages to adjacent residents. In this study, it is assumed that emergency valve systems are installed under a ground and the efficacy of these is verified. Consequence analysis program was employed to evaluate the mitigation impact of emergency valve systems. The results show that these valve systems are economical and their performances for a mitigation are excellent. The results indicate that the installation of emergency valve systems for underground pipelines should be urgently legislated and performed.

• Journal of the Korea Computer Graphics Society
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• v.25 no.3
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• pp.55-63
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• 2019

Recently, the GPU computing method has been utilized to improve the performance of the physics simulation field. In particular, in the case of a deformed object simulation requiring a large amount of computation, a GPU-based parallel processing algorithm is required to guarantee real-time performance. We have studied the parallel structure design method to improve the performance of the mass spring simulation method which is one of the methods of implementing the deformation object simulation. We used OpenGL's GLSL, a graphics library that allows direct access to the GPU, and implemented the GPGPU environment using an independent pipeline, the compute shader. In order to verify the effectiveness of the parallel structure design method, the mass - spring system was implemented based on CPU and GPU. Experimental results show that the proposed method improves computation speed by about 6,000% compared to the CPU Environment. It is expected that the lightweight simulation technology can be effectively applied to the augmented reality and the virtual reality field by using the design method proposed later in this research.

• Plant Breeding and Biotechnology
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• v.5 no.2
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• pp.134-142
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• 2017

Resource plants are important and have strong potential for a variety of utilities as crops or pharmaceutical materials. However, most resource plants remain wild and thus their utility for breeding and biotechnology is limited. Molecular markers are useful to initiate genetic study and molecular breeding for these understudied resource plants. We collected various wild collections of Peucedanum japonicum which is indigenous resource plants utilized as oriental medicine and leafy vegetables in Korea. In this study, we produced two independent whole genome sequences (WGSs) from two collections and identified large scale polymorphic simple sequence repeat (pSSR) based on our pipeline to develop SSR markers based on comparison of two WGSs. We identified a total of 452 candidate pSSR contigs. To confirm the accuracy and utility of pSSR, we designed ten SSR primer pairs and successfully applied those to seven collections of P. japonicum. The WGS and pSSR candidates identified in this study will be useful resource for genetic research and breeding purpose for the valuable resource plant, P. japonicum.

• Journal of The Korean Astronomical Society
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• v.55 no.4
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• pp.111-121
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• 2022

Based on the light an exoplanet blocks from its host star as it passes in front of it during a transit, the mid-transit time can be determined. Periodic variations in mid-transit times can indicate another planet's gravitational influence. We investigate 83 transits of TrES-1 b as observed from 6-inch telescopes in the MicroObservatory robotic telescope network. The EXOTIC data reduction pipeline is used to process these transits, fit transit models to light curves, and calculate transit midpoints. This paper details the methodology for analyzing transit timing variations (TTVs) and using transit measurements to maintain ephemerides. The application of Lomb-Scargle period analysis for studying the plausibility of TTVs is explained. The analysis of the resultant TTVs from 46 transits from MicroObservatory and 47 transits from archival data in the Exoplanet Transit Database indicated the possible existence of other planets affecting the orbit of TrES-1 and improved the precision of the ephemeris by one order of magnitude. We now estimate the ephemeris to be (2 455 489.66026 BJD_TDB ± 0.00044 d) + (3.0300689 ± 0.0000007) d × epoch. This analysis also demonstrates the role of small telescopes in making precise midtransit time measurements, which can be used to help maintain ephemerides and perform TTV analysis. The maintenance of ephemerides allows for an increased ability to optimize telescope time on large ground-based telescopes and space telescope missions.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.279-286
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• 2013

This paper introduces a new method for identification of building energy performance problems. The presented method is based on automated analysis and visualization of deviations between actual and expected energy performance of the building using EPAR (Energy Performance Augmented Reality) models. For generating EPAR models, during building inspections, energy auditors collect a large number of digital and thermal imagery using a consumer-level single thermal camera that has a built-in digital lens. Based on a pipeline of image-based 3D reconstruction algorithms built on GPU and multi-core CPU architecture, 3D geometrical and thermal point cloud models of the building under inspection are automatically generated and integrated. Then, the resulting actual 3D spatio-thermal model and the expected energy performance model simulated using computational fluid dynamics (CFD) analysis are superimposed within an augmented reality environment. Based on the resulting EPAR models which jointly visualize the actual and expected energy performance of the building under inspection, two new algorithms are introduced for quick and reliable identification of potential performance problems: 1) 3D thermal mesh modeling using k-d trees and nearest neighbor searching to automate calculation of temperature deviations; and 2) automated visualization of performance deviations using a metaphor based on traffic light colors. The proposed EPAR v2.0 modeling method is validated on several interior locations of a residential building and an instructional facility. Our empirical observations show that the automated energy performance analysis using EPAR models enables performance deviations to be rapidly and accurately identified. The visualization of performance deviations in 3D enables auditors to easily identify potential building performance problems. Rather than manually analyzing thermal imagery, auditors can focus on other important tasks such as evaluating possible remedial alternatives.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.152-160
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• 2009

The pipe jacking method which is a non-excavation method is frequently used due to constructability and economical efficiency in a medium or small-sized pipeline construction. However, jacking process of the method still causes problems that the base ground is disturbed and loosen. These lead to surface settlement, strength decrease and leakage of water. Therefore, this study presents in-situ application of the steel pipe jacking with grouting, and it is that jacking and grouting are progressed simultaneously. To verify this, the steel pipe jacking with grouting and the existing steel pipe jacking have been constructed on the same ground condition. It has been proved that the steel pipe jacking with grouting is in-situ applicable according to results of monitoring surface settlement, in-situ density, GPR geophysical prospecting and large scale direct shear test.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2352-2366
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• 2024

Reinforced concrete (RC) shear walls with precast steel-concrete composite modular (PSCCM) are strongly recommended in the structural design of nuclear power plants due to the need for a large number of process pipeline crossings and industrial construction. However, the effect of the PSCCM on the mechanical behavior of the whole RC shear wall is still unknown and has received little attention. In this study, three 1:3 scaled specimens, one traditional shear wall specimen (TW) and two shear wall specimens with the PSCCM (PW1, PW2), were designed and investigated under cyclic loadings. The failure mode, hysteretic curve, energy dissipation, stiffness and strength degradations were then comparatively investigated to reveal the effect of the PSCCM. Furthermore, numerical models of the RC shear wall with different PSCCM distributions were analyzed. The results show that the shear wall with the PSCCM has comparable mechanical properties with the traditional shear wall, which can be further improved by adding reinforced concrete constraints on both sides of the shear wall. The accumulated energy dissipation of the PW2 is higher than that of the TW and PW1 by 98.7 % and 60.0 %. The failure of the shear wall with the PSCCM is mainly concentrated in the reinforced concrete wall below the PSCCM, while the PSCCM maintains an elastic working state as a whole. Shear walls with the PSCCM arranged in the high stress zone will have a higher load-bearing capacity and lateral stiffness, but will suffer a higher risk of failure. The PSCCM in the low stress zone is always in an elastic working state.

• The Journal of Bigdata
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• v.8 no.2
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• pp.83-95
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• 2023

Big data analytics and AI play a critical role in the development of smart plants. This study presents a big data platform for plant data and an 'AutoML platform' for AI-based plant O&M(Operation and Maintenance). The big data platform collects, processes and stores large volumes of data generated in plants using Hadoop, Spark, and Kafka. The AutoML platform is a machine learning automation system aimed at constructing predictive models for equipment prognostics and process optimization in plants. The developed platforms configures a data pipeline considering compatibility with existing plant OISs(Operation Information Systems) and employs a web-based GUI to enhance both accessibility and convenience for users. Also, it has functions to load user-customizable modules into data processing and learning algorithms, which increases process flexibility. This paper demonstrates the operation of the platforms for a specific process of an oil company in Korea and presents an example of an effective data utilization platform for smart plants.

• Journal of Korean Society of Disaster and Security
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• v.17 no.3
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• pp.1-11
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• 2024

The purpose of this study is to develop a fluidity-improved refilling material that satisfies smooth construction and long-term durability in a low-temperature environment using special materials and field soil as a refilling material to develop technology for high-speed installation of long-term non-traditional pipelines on poor ground containing a large amount of organic soil in a low-temperature environment. To this end, a special cement material was developed, and an indoor test was conducted to determine the construction performance and durability of the fluidity improved refilling material mixed with the developed special material and field soil to meet the quality standards for field construction. The construction quality standard items of fluidity improved refill materials were set to meet the CLSM (ACI 229R-13) standard suggested by the American ACI (America Concrete Institute). In addition, in order to understand the applicability in a low-temperature environment, the test was performed with the same items at low temperature and compared with the indoor test results at room temperature.