• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.21-22
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• 2011

Recently, the development of alternative energy technologies has been actively conducted for energy conservation and CO₂ emission reduction. Especially, photovoltaic energy has been applied practically in construction industry, and research on the building-integrated photovoltaic system (BIPV) that can replace fossil fuel for building operation and maintenance has been performed. However, this vibrant research has been limited to the use phase of buildings, and few studies have been carried out in the construction phase. The construction duration and the scale of the sites have increased along with the high-rise trend of buildings, and it is forecasted that the temporary electricity use and CO₂ emission in the construction phase is increasing. In sight of these developments, this research analyzed applicability of the photovoltaic system for the construction phase that can replace the electricity used on the high-rise construction site.

• Journal of the Korean Ceramic Society
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• v.30 no.9
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• pp.723-730
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• 1993

The mechanism of formation of perovskite phase and the dielectric properties of PZMN[Pb(Zn, Mg)1/3Nb2/3O3] ceramics were examined using two different types of the columbite precursors, (Mg, Zn)Nb2O6 (MZN) and MgNb2O6＋ZnNb2O6 (MN＋ZN). The formatin of perovskite phase in PbO＋MN＋ZN system is characterized by an initial rapid formation of Mg-rich perovskite phase, followed by a sluggish formation of Zn-rich perovskite phase. On the other hand, thepyrochlore/perovskite transformation in the PbO＋MZN system proceeded uniformly with a spatial homogeneity. The degree of diffuseness of the rhombohedral/cubic phase transitionis higher in the PbO＋MN＋ZN system than in the PbO＋MZN specimen, indicating a broadened compositional distributjion of the B-site catons (Nb+5, Zn+2, Mg+2) in the PbO＋MN＋ZN system.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.176-181
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• 2010

The evaluation of shear modulus (or shear wave velocity) profile of the site is very important in various fields of geotechnical engineering. In the field, there exist spatial variations of shear modulus that case uncertainty in the geotechnical analysis or design. So it is necessary to evaluate the spatial variation of shear wave velocities of the soil site. In this study, the HWAW method is applied to the determination of a 3-D Vs map of soil site. The HWAW method, which is based on harmonic wavelet transforms, has been developed to determine phase and group velocities of waves. The HWAW method uses only the signal portion of the maximum local signal/noise ratio to evaluate the phase velocity in order to minimize the effect of the noise. The field testing of this method is relatively simple and fast because only one experimental setup, which consists of one pair of receivers on the surface, is needed using a short receiver spacing setup (1~3m). These characteristics make it possible to determine detailed local Vs profile in the site with lateral Vs variation and to evaluate 3-D Vs map by performing a series of tests on the grid. To estimate the applicability of the proposed method, field tests were performed. Through field applications validity and applicability of the proposed method were verified.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_1
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• pp.161-168
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• 2022

This study proposed a new approach to impliment a robusut control of comsumer-friendly flexible manipulator with five joint for untact working in filed work-site. The output redefinition approach was used to overcome the non minimum phase characteristic of the system. The new output is defined so that the zero dynamics related to this output are stable. The control strategy is based on an computed torque method which is applicable to a class of time-invariamt phase linear systems whose uncertainties appear in output loop stable. The controller is composed of a stabilizing joint controller and an output redefinition tracking controller. Experimental results are also presented to verify the effectiveness of the proposed control scheme.

• Smart Structures and Systems
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• v.30 no.3
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• pp.317-325
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• 2022

Among the approaches to the production of "green" energy, geothermal power systems are becoming quite popular in Europe. Their installation in existing buildings requires an extended, external pipes appendix and its laying operation needs a drilling activities nearby structural skeletons often designed to support static loads only, especially when ancient buildings are targeted. This contribution reports and discusses the experimental results achieved within a specific case study within the European project GEOFIT. In particular, standard accelerometric measurements in and nearby a single-story reinforced concrete building are collected and analysed in the absence of drilling (pre-drilling) and during drilling activities (drilling phase) to monitor the structure response to the external source of vibrations related to the excavations phase. The target is to outline automatic guidelines toward installations preventing from any sort of structural damage.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.367-376
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• 2002

As of September 2002, there are more than 60 operational permanent Global Positioning System (GPS) stations in South Korea. Their data are being used for a variety of purposes: geodynamics, geodesy, real-time navigation, atmospheric science, and geography. Especially, many of the sites are reference stations for DGPS (Differential GPS). However, there has been no comprehensive and qualitative analysis published to evaluate the data quality. In this study, we present preliminary results of our assessment of the permanent GPS sites in South Korea. We have analyzed the multi-path characteristics of each station using a quality-checking software package called TEQC. Another multipath analysis tool based on post-fit phase residuals was used to check the repeating patterns and the amount of the multipath at each site. The long-term stability of each station was analyzed using the root-mean-square (RMS) error of the estimated site positions for one year, which enabled us to evaluate the mount stability. In addition, the number of cycle slips at each site was derived by TEQC. Based on these series of tests, we compared the stability and data quality of permanent GPS stations in South Korea.

• Earthquakes and Structures
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• v.17 no.6
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• pp.557-566
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• 2019

The evaluation of the seismic hazard for a given site is to estimate the seismic ground motion at the surface. This is the result of the combination of the action of the seismic source, which generates seismic waves, the propagation of these waves between the source and the site, and site local conditions. The aim of this work is to evaluate the sensitivity of dynamic response of extended structures to spatial variable ground motions (SVGM). All factors of spatial variability of ground motion are considered, especially local site effect. In this paper, a method is presented to simulate spatially varying earthquake ground motions. The scheme for generating spatially varying ground motions is established for spatial locations on the ground surface with varying site conditions. In this proposed method, two steps are necessary. Firstly, the base rock motions are assumed to have the same intensity and are modelled with a filtered Tajimi-Kanai power spectral density function. An empirical coherency loss model is used to define spatial variable seismic ground motions at the base rock. In the second step, power spectral density function of ground motion on surface is derived by considering site amplification effect based on the one dimensional seismic wave propagation theory. Several dynamics analysis of a curved viaduct to various cases of spatially varying seismic ground motions are performed. For comparison, responses to uniform ground motion, to spatial ground motions without considering local site effect, to spatial ground motions with considering coherency loss, phase delay and local site effects are also calculated. The results showed that the generated seismic signals are strongly conditioned by the local site effect. In the same sense, the dynamic response of the viaduct is very sensitive of the variation of local geological conditions of the site. The effect of neglecting local site effect in dynamic analysis gives rise to a significant underestimation of the seismic demand of the structure.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.272-284
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• 1996

The present study has quantitatively assessed the regional production, income and employment impact resulting from the construction and operation of nuclear power plant (NPP) upon the domestic local areas by applying the regional input-output analysis model to the case of Wolsong unit-l site. The conclusions regarding the most likely regional economic impacts upon the wolsong site are summarized as follows: 1. The income multipliers are calculated to be 1.563 for the construction phase and 1.500 for the operation phase. These values are relatively high compared with those of other conventional facilities. 2. The level of total employee's wage induced employment associated with the construction phase has been estimated to be 37,000 while that with the operational phase in 1990 to be 5,610. 3. With relation to the aspect of resident welfare it is found that the industrial sector associated with electricity, gas and water supply have remarkably improved with the construction of the NPP. 4. The NPP siting has induced substantial changes in interindustry (input-output) structures of the Wolsong unit-l site which is one of the rural areas where all the domestic NPPs are sited. Such changes are attributed to the industrial recomposition of the region. 5. With the application of other regional economic analysis models and the use of more sufficient regional data, other detailed studies on the economic impact analysis of domestic NPP-related facility sitings are suggested to be carried out further since the influence of NPP sitings is significant to the national economic impact as well as the regional economic impact.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.109-126
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• 2006

As the national interest in sports has been increased over time, sports facilities and sports complex are considered more than just physical environments for training athletes or watching games. Sports facilities now become symbolic spatial devices to represent the national and cultural pride of any countries. The existing national training camp located in Taenung, Seoul is gotting outdated and degraded. The polluted air in the city risks athletes' health condition. The government planned to construct the second training camp at Jincheon, Chungbuk at the area of $2,171,910m^2$. The Korea Sports Council called for proposals to envision the future training camp, and they held a design competition from August to November, 2005. The first phase was to present the masterplan for the entire site including training buildings, outdoor training facilities, dormitories, a visitor center, a research center, education and administration buildings. Considering the size of the site, the planning process required a strong relationship between landscape and architecture. This study tries to provide general explanations on the winning proposal focused on the landscape-related issues. It also attempts to have reference points for contemporary planning and design issues to situate the project in the stream of continuing design effort to avoid the dichotomy between nature and culture. The landscape proposal for the new national taming camp suggests four main strategies; 1) The camp has two intersecting and interweaving parks which represent the natural and urban order. 2) The entire site is organized and networked by the flow of landscape called landscape ribbon in terms of topography, vegetation, and water flow. 3) The landscape is choreographed through the time and process. 4) The ecological process and the digital contents are juxtaposed in the landscape. This winning proposal is the first step to portray the national vision for the sustainable environment coexisting with sports industry. Landscape in this proposal is an active agent to network various parts of the site which enables landscape to be infrastructure. Landscape design in this proposal should be considered open-ended strategies rather than determined concrete forms and its engaging further development will be tested in following Design-Build phase.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.782-787
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• 2023

Korea augmentation satellite system (KASS) integration, verification, qualification (IVQ) activity is verification of requirements for KASS system and its sub-system that were performed based on the inspection, analysis, review of design, test (IART) method from factory acceptance test (FAT) to test readiness review (TRR) after critical design review (CDR) was closed. In the FAT phase, developed equipment was installed on the test platform and we were verified interfaces between sub-systems and coupling test with the kass control station (KCS). In the site aceeptance test (SAT) phase, on-site verification was conducted by installing equipment verified by FAT such as kass reference station (KRS), kass processing station (KPS), kass uplink station (KUS), KCS. However, considering the developed plan and status, SAT was divided into 3 phases and coupling test was performed. In the TRR phase, the KASS system verification was performed through FAT's test list and additional test list using the satellite based augmentation system (SBAS) broadcast signal from geostationary earth orbit (GEO) 1.