• Current Optics and Photonics
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• v.6 no.3
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• pp.337-343
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• 2022

Microfluidic chips are new devices that can manipulate liquids at the micrometer level, and terahertz (THz) time-domain spectroscopy has good applicability in biochemical detection. The combination of these two technologies can shorten the distance between sample and THz wave, reduce THz wave absorption by water, and more effectively analyze the kinetics of biochemical reactions in aqueous solutions. This study investigates the effects of different external magnetic field intensities on the THz transmission characteristics of deionized water, CuSO₄, CuCl₂, (CH₃COO)₂Cu, Na₂SO₄, NaCl, and CH₃COONa; the THz spectral intensity of the sample solutions decrease with increasing intensity of the applied magnetic field. Analysis shows that the magnetic field leads to a change in the dipole moment of water molecules in water and electrolyte solutions, which enhances not only the hydrogen-bond networking ability of water but also the hydration around ions in electrolyte solutions, increasing the number of hydrogen bonds. Increasing the intensity of this magnetic field further promotes the hydrogen-bond association between water molecules, weakening the THz transmission intensity of the solution.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.72-78
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• 2020

The present study developed shotcrete for fiber-net integrated tunnel support system, which consists of fiber-net support materials including netlike fiber and shotcrete and integration technology between support materials. In addition, in order to evaluate the field applicability of the developed tunnel support system and compare with the performance of steel fiber reinforced shotcrete, mock -up test was conducted on the mock -up structure. The test results show that in the case of shotcrete containing coarse aggregate(S20A5RP10-C), the excessive rebound rate occurred as the secondary shotcrete was dropped during construction due to the degradation in bond performance with fiber-net. Also, in the case of steel fiber reinforced shotcrete, the amount of cast shotcrete fell short of target value due to the fiber ball and the degradation of pumpability. On the other hand, the amount of cast mortar shotcrete(S20A5RP10-M) and the installation position of fiber-net were almost close to the target values, and the lower rebound rate occurred compared to the steel fiber reinforced shotcrete.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.12-18
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• 2024

High-rise, large-scale, and diversification of buildings are possible, and the reduction of concrete cross-sections reduces the weight of the structure, thereby increasing or decreasing the height of the floor, securing a large number of floors at the same height, securing a large effective space, and reducing the amount of materials, rebar, and concrete used for designating the foundation floor. In terms of site construction and quality, a low water binder ratio can reduce the occurrence of dry shrinkage and minimize bleeding on the concrete surface. It has the advantage of securing self-fulfilling properties by improving fluidity by using high-performance sensitizers, making it easier to construct the site, and shortening the mold removal period by expressing early strength of concrete. In particular, with the rapid development of concrete-related construction technology in recent years, the application of ultra-high-strength concrete with a design standard strength of 100 MPa or higher is expanding in high-rise buildings. However, although high-rise buildings with more than 120 stories have recently been ordered or scheduled in Korea, the research results of developing ultra-high-strength concrete with more than 130 MPa class considering field applicability and testing and evaluating the actual applicability in the field are insufficient. In this study, in order to confirm the applicability of ultra-high-strength concrete in the field, a preliminary experiment for the member of a reduced simulation was conducted to find the optimal mixing ratio studied through various indoor basic experiments. After that, 130 MPa-class ultra-high-strength concrete was produced in a ready-mixed concrete factory in a mock member similar to the life size, and the flow characteristics, strength characteristics, and hydration heat of concrete were experimentally studied through on-site pump pressing.

• Korean Journal of Environmental Biology
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• v.35 no.1
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• pp.13-20
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• 2017

Greenhouse gas emission from agricultural land is recognized as an important factor influencing climatic change. In this study, the national $CO_2$ emission was estimated for paddy soils, using soil GHG emission model (DNDC) with $1km^2$ scale. To evaluate the applicability of the model in Korea, verification was carried out based on field measurement data using a closed chamber. The total national $CO_2$ emission in 2015 was estimated at $5,314kt\;CO_2-eq$, with the emission per unit area ranging from $2.2{\sim}10.0t\;CO_2-eq\;ha^{-1}$. Geographically, the emission of Jeju province was particularly high, and the emission from the southern region was generally high. The result of the model verification analysis with the field data collected in this study (n=16) indicates that the relation between the field measurement and the model prediction was statistically similar (RMSE=22.2, ME=0.28, and $r^2=0.53$). More field measurements under various climate conditions, and subsequent model verification with extended data sets, are further required.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.300-307
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• 1998

It is not an easy task for forest managers to make sound decisions on forest management and operations planning because of huge sets of spatial and temporal data and complex decision-making processes involved. However, as an efficient tool, GIS techniques enable them to enhance broad understandings on forest inventory and management conditions. In this study, we developed a GIS model for field use in forest management. In building the model, we have chosen MapInfo version 4.0 as the basic engine of the model. The model also includes an interface module to help forest managers use MapInfo functions easily. It handles MapInfo functions required to manage inventory data and analyze spatial distributions of forest stands. For testing field applicability of the model, we have build field data sets for a district of Chunchun National Forest. Then, we tested functions through quarrying stand attributes and constructing thematic maps. In this paper, the structures and functions of the model as well as the results of field applications are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.612-616
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• 1997

In this paper, two kinds of controller are proposed for a soccer robot system.. One for Supervisor and defense mode, and the other for attack mode. Robot soccer game has very dynamic characteristics. Furthermore, there exist competitions between agents. The soccer-playing robot should take an appropriate action according to its surroundings. Initially, an attack mode controller using a vector field concept is designed, then a supervisor and a defense mode controller are designed with a Petri-net. The efficiency and applicability of the proposed controllers are demonstrated through a real robot soccer game(MiroSot 97).

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.489-495
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• 2000

When microorganisms such as bacteria and fungi are injected into porous medium such as soils along with appropriate substrate and nutrients, biomass retained in the soil pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrates and nutrients. Biomass-soil mixture was evaluated its applicability to the field condition as an alternative liner material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.370-375
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• 1998

The objectives of this study are to evaluate the applicability of SCS TR-20 model for small ungauged watershed, to show the behavior of the model with variation of topography in watershed, and to evaluate the storage effect of paddy field for flood flow. For this purpose, simulated data from the model were compared with the observed flood data at two sites (HS#3, HS#4) in Balan watershed. From the comparison between simulated and observed data, it was found that the model is applicable to this watershed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.7
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• pp.339-342
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• 2005

We present a new high-frequency equivalent circuit model for 52pin QFP used in typical IC's and extract R, L, and C values of this circuit model using a 3-D E & M field simulator. Futhermore, L and C value variations as a function of Pin number due to the shape differences of the leads have been fitted to 2nd order polynomials in order to extend the applicability of this model.

• Journal of Korean Society for Quality Management
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• v.27 no.4
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• pp.216-228
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• 1999

This study investigates the applicability of total quality management in the field of education, called the total quality education (TQE) It, first, reviews a few case studies in order to observe the characteristics of TQE and the feedbacks from practitioners. The key factors of TQE are then analyzed in terms of both the education concepts and the responsibilities of stakeholders. Finally, the relevancy of various TQE approaches and tools to the stakeholdership is studied.