• Title/Summary/Keyword: large-scale structure

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Development of the Spatial Indexing Method for the Effective Visualization of BIM data based on GIS (GIS 기반 BIM 데이터의 효과적 가시화를 위한 공간인덱싱 기법 개발)

  • Kim, Ji-Eun;Kang, Tae-Wook;Hong, Chang-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.8
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    • pp.5333-5341
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    • 2014
  • Recently, with the increasing interest in facility management based on indoor spatial information, various studies have been attempted to manage facility conversion between BIM and GIS. Visualization of the geometry data for a large-scale is one of the major issues to the maintenance system. Therefore, this study designed the spatial indexing algorithm through an IFC schema-based scenario for the effective visualization of BIM data based on GIS. A part of the algorithm was developed implementing the OcTree structure and this research has a test for the developed output with IFC sample data. Ultimately, we propose the spatial indexing method for the effective visualization of BIM data based on GIS.

Fabrication of Size-Controlled Hole Array by Surface-Catalyzed Chemical Deposition (표면 촉매 화학 반응을 이용한 크기 조절이 가능한 홀 어레이 제작)

  • Park, Hyung Ju;Park, Jeong Won;Lee, Dae-Sik;Pyo, Hyeon-Bong
    • Journal of Sensor Science and Technology
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    • v.27 no.1
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    • pp.55-58
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    • 2018
  • Low-cost and large-scale fabrication method of nanohole array, which comprises nanoscale voids separated by a few tens to a few hundreds of nanometers, has opened up new possibilities in biomolecular sensing as well as novel frontier optical devices. One of the key aspects of the nanohole array research is how to control the hole size following each specific needs of the hole structure. Here, we report the extensive study on the fine control of the hole size within the range of 500-2500 nm via surface-catalyzed chemical deposition. The initial hole structures were prepared via conventional photo-lithography, and the hole size was decreased to a designed value through the surface-catalyzed chemical reduction of the gold ion on the predefined hole surfaces, by simple dipping of the hole array device into the aqueous solution of gold chloride and hydroxylamine. The final hole size was controlled by adjusting reaction time, and the optimal experimental condition was obtained by doing a series of characterization experiments. The characterization of size-controlled hole array was systematically examined on the image results of optical microscopy, field emission scanning electron microscopy(FESEM), atomic-force microscopy(AFM), and total internal reflection microscopy.

On the Safety and Performance Demonstration Tests of Prototype Gen-IV Sodium-Cooled Fast Reactor and Validation and Verification of Computational Codes

  • Kim, Jong-Bum;Jeong, Ji-Young;Lee, Tae-Ho;Kim, Sungkyun;Euh, Dong-Jin;Joo, Hyung-Kook
    • Nuclear Engineering and Technology
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    • v.48 no.5
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    • pp.1083-1095
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    • 2016
  • The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodiumshowed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

Application of Cost Estimation to Space Launch Vehicle Development Program (우주발사체 개발사업의 비용 추정 현황 및 사례)

  • Yoo, Il-Sang;Seo, Yun-Kyoung;Lee, Joon-Ho;Oh, Bum-Seok
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.30 no.3
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    • pp.165-173
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    • 2007
  • A space launch vehicle system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as mechanical structure, electronics, control, telecommunication, propulsion, material engineering etc. A lot of cost is required to develop the launch vehicle system. A precise planning of R&D cost is very essential to make a success of the launch vehicle development program. Especially in the early development phase of a new space launch vehicle system, cost estimation techniques and analogy from past similar development data are very useful methods to estimate a development cost of the launch vehicle system. Now Korea Aerospace Research Institute is in charge of the KSLV-I (Korea Space Launch Vehicle-I) Program that is a part of Korea National Space program. KSLV-I Program is a national undertaking to develop launch capabilities to deliver science satellites of a 100kg-class into a low earth orbit. It is hereafter, going to plan to develop a new korean space launch vehicle. In this paper, first the development costs of well-known launch vehicles in the world are presented to provide a reference to make a development plan of a new launch vehicle. Second this paper introduces the present status of cost estimation applications at NASA. Finally this paper presents the results from application of a TRANSCOST, a parametric cost model, to derive a cost estimate of a new launch vehicle development, as an example.

Activities of IEA SolarPACES & Task Programs (IEA SolarPACES 및 Task 활동)

  • Kang, Yong-Heack;Kim, Jong-Kyu;Lee, Hyun-Jin
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.246-249
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    • 2011
  • SolarPACES is an international cooperative network bringing together teams of national exports from around the world to focus on the development and marketing of concentrating solar power systems (also known as solar thermal power systems). It is one of a number of collaborative programs, called Implementing Agreements, managed under the umbrella of the International Energy Agency to help find solutions to worldwide energy problems. Technology development is at the core of the work of SolarPACES. Member countries work together on activities aimed at solving the wide range of technical problems associated with commercialization of concentrating solar technology, including large-scale system tests and the development of advanced technologies, components, instrumentation, and systems analysis techniques. In addition to technology development, market development and building of awareness of the potential of concentrating solar technologies are key elements of the SolarPACES program The Implementing Agreement specifies broad "Tasks," or thematic areas of work SolarPACES currently has three ongoing tasks, focusing on concentrating solar electric power systems (Task I), solar chemistry research (Task II), and solar technology and applications (Task III). An Operating Agent, nominated by the ExCo, is responsible for overseeing the work of each task Each task maintains a detailed program of work that defines all task activities, including their objectives, participants, plans, and budgets. In addition to technical reports of the activities and their participants, accomplishments and progress are summarized in the SolarPACES annual report. Many SolarPACES activities involve close cooperation among member countries (either through sharing of task activities or, occasionally, cost-sharing), although some cooperation is limited to sharing of information and results with other participants. In this paper, structure, works, and members of SolarPACES and Korean activies in the SolarPACES are introduced.

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A Study on Implementation of Monitoring System of Distributed Simulation for Underwater Warfare (수중 교전 모의를 위한 HLA/RTI 기반 시뮬레이션의 모니터링 시스템 구축 연구)

  • Hwam, Won K.;Chung, Yongho;Choi, Jong-Yeob;Park, Sang C.
    • Journal of the Korea Society for Simulation
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    • v.22 no.2
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    • pp.73-83
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    • 2013
  • This paper presents design and implementation of the monitoring system for the distributed simulation of underwater warfare. As importance of defense modeling and simulation(M&S) has raised, Simulation-Based Acquisition(SBA) was authorized for an obligatory process in the development process of weapon systems. Yet, it requires tremendous resources to develop a large-scale simulation system that describes complex and broad battlefields. Therefore, an approach of the distributed system was devised to develop a new simulation system combining legacy simulators that were developed for confined purpose and sole operations. High-Level Architecture(HLA) of distributed systems is a standardized protocol by IEEE for the distributed simulation system and Run-Time Infrastructure(RTI) is an implementation of HLA to structure efficient distributed systems. The main objective of this paper is to derive appropriate monitoring factors for underwater warfare simulation, design and implementation of the monitoring system to analyze the factors based on HLA/RTI.

Activities of IEA SolarPACES & Task Programs (IEA SolarPACES 및 Task 활동)

  • Kang, Yong-Heack;Kim, Jong-Kyu;Lee, Hyun-Jin
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.320-323
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    • 2011
  • SolarPACES is an international cooperative network bringing together teams of national experts from around the world to focus on the development and marketing of concentrating solar power systems (also known as solar thermal power systems). It is one of a number of collaborative programs, called Implementing Agreements, managed under the umbrella of the International Energy Agency to help find solutions to worldwide energy problems. Technology development is at the core of the work of Solar PACES. Member countries work together on activities aimed at solving the wide range of technical problems associated with commercialization of concentrating solar technology, including large-scale system tests and the development of advanced technologies, components, instrumentation, and systems analysis techniques. In addition to technology development, market development and building of awareness of the potential of concentrating solar technologies are key elements of the Solar PACES program. The Implementing Agreement specifies broad "Tasks," or thematic areas of work. SolarPACES currently has three ongoing tasks, focusing on concentrating solar electric power systems (Task I), solar chemistry research (Task II), and solar technology and applications (Task III). An Operating Agent, nominated by the ExCo, is responsible for overseeing the work of each task. Each task maintains a detailed program of work that defines all task activities, including their objectives, participants, plans, and budgets. In addition to technical reports of the activities and their participants, accomplishments and progress are summarized in the SolarPACES annual report. Many SolarPACES activities involve close cooperation among member countries (either through sharing of task activities or, occasionally, cost-sharing), although some cooperation is limited to sharing of information and results with other participants. In this paper, structure, works, and members of SolarPACES and Korean activies in the SolarPACES are introduced.

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Origin of Dark-Energy and Accelerating Universe

  • Keum, Yong-Yeon
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.34.1-34.1
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    • 2009
  • After SNIa and WMAP observations during the last decade, the discovery of the accelerated expansion of the universe is a major challenge to particle physics and cosmology. There are currently three candidates for the dark energy which results in this accelerated expansion: $\cdot$ a non-zero cosmological constant, $\cdot$ a dynamical cosmological constant (quintessence scalar field), $\cdot$ modifications of Einstein's theory of gravity. The scalar field model like quintessence is a simple model with time-dependent w, which is generally larger than -w1. Because the different w lead to a different expansion history of the universe, the geometrical measurements of cosmic expansion through observations of SNIa, CMB and baryon acoustic oscillations (BAO) can give us tight constraints on w. One of the interesting ways to study the scalar field dark-energy models is to investigate the coupling between the dark energy and the other matter fields. In fact, a number of models which realize the interaction between dark energy and dark matter, or even visible matter, have been proposed so far. Observations of the effects of these interactions will offer an unique opportunity to detect a cosmological scalar field. In this talk, after briefly reviewing the main idea of the three possible candidates for dark energy and their cosmological phenomena, we discuss the interactinng dark-energy model, paying particular attention to the interacting mechanism between dark energy with a hot dark matter (neutrinos). In this so-called mass-varying neutrino (MVN) model, we calculate explicitly the cosmic microwave background (CMB) radiation and large-scale structure (LSS) within cosmological perturbation theory. The evolution of the mass of neutrinos is determined by the quintessence scalar field, which is responsible for the cosmic acceleration today.

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Heterologous Expression and Characterization of a Thermostable Exo-β-D-Glucosaminidase from Aspergillus oryzae

  • Wu, Dingxin;Wang, Linchun;Li, Yuwei;Zhao, Shumiao;Peng, Nan;Liang, Yunxiang
    • Journal of Microbiology and Biotechnology
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    • v.26 no.2
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    • pp.347-355
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    • 2016
  • An exo-β-D-glucosaminidase (AorCsxA) from Aspergillus oryzae FL402 was heterologously expressed and purified. The deduced amino acid sequence indicated that AorCsxA belonged to glycoside hydrolase family 2. AorCsxA digested colloid chitosan into glucosamine but not into chitosan oligosaccharides, demonstrating exo-β-D-glucosaminidase (CsxA) activity. AorCsxA exhibited optimal activity at pH 5.5 and 50℃; however, the enzyme expressed in Pichia pastoris (PpAorCsxA) showed much stronger thermostability at 50℃ than that expressed in Escherichia coli (EcAorCsxA), which may be related to glycosylation. AorCsxA activity was inhibited by EDTA and most of the tested metal ions. A single amino acid mutation (F769W) in AorCsxA significantly enhanced the specific activity and hydrolysis velocity as revealed by comparison of Vmax and kcat values with those of the wild-type enzyme. The three-dimensional structure suggested the tightened pocket at the active site of F769W enabled efficient substrate binding. The AorCsxA gene was heterologously expressed in P. pastoris, and one transformant was found to produce 222 U/ml activity during the high-cell-density fermentation. This AorCsxA-overexpressing P. pastoris strain is feasible for large-scale production of AorCsxA.

Numerical Model Experiments on the Tidal Current Variations Due to the Bridge Piers Construction near the Straits of Narodo Islands (교각건설로 인한 나로도 협수로 부근해역에서의 조류변화 수치모형 실험)

  • LEE Moon-Ock
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.1
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    • pp.47-58
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    • 1994
  • Field observation and numerical experiments with a two-dimensional depth-integrated model were undertaken in order to investigate some of the effects on the flow structure resulting from the construction of a bridge connecting Kohung Peninsula and the Narodo Islands on the southern coast of Korea. Tidal currents passing through the straits between the Narodo Islands showed that, although the phase lagged one hour behind that passing through the strait between Kohung Peninsula and Naenarodo Island, it still kept strong flows of more than 80cm/sec near the bottom. The seawater temperature and salinity within the study area seemed to be higher southward but uniform vertically. The results of the drogue experiments in the straits between the Narodo Islands showed that the drogues moved northward of Sayangdo in the early part of the flood tide, but southward in the late part of the flood tide and finally stopped a mile from the east coast of Surakdo. On the other hand, the numerical computation showed that the flow structures after construction of the bridge piers were basically in line with those before construction of the bridge piers, except for the slight variations of velocities in the vicinity of the bridge piers. A large scale clockwise circulation has been confirmed in the south area of Namsungri of Kohung Peninsula from the computational results of tide-induced residual currents. Referring to these computational results, the impact category on the flow structures due to the bridge piers construction has been estimated to be within around 2km. The results were in good agreement with the field observations.

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