• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.136-145
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• 2006

SWAT includes a lot of parameters related with geography, hydrological time series, land management and water pollution, etc. So, it needs many spatial, non-spatial and time series data to run SWAT. If SWAT is operated in conjunction with GIS, we can use database which includes model input data and do all the processes which covers data creation, model input and analysis of simulation results in a system. The objective of this study is to develop HyGIS-SWAT which is the interface system to couple the SWAT model and HyGIS. To achieve this object, system operation process based on HyGIS-SWAT data model is evaluated and databases are designed and established. As a result, HyGIS-SWAT prototype system is developed. HyGIS data model and HyGIS-Model operation process can be applied effectively to the development of HyGIS-SWAT. The technologies from this study can be used as base technology to develop another HyGIS application which connect HyGIS with models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.3
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• pp.327-338
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• 1993

This paper proposes a novel method for deriving the Fourier transform pairs of high order pulses given in a generalized form. Primarily, modifying the PRS system model, we establish a new model which simplifies the process of Fourier analysis of the n-th order pulse signal, resulting in a representative relationship. In succession, we present the Frame Formula which plays a role of substituent for the parameters in table look-up procedures. Each look-up table contains all the parameters needed to obtain the Fourier transform of the corresponding pulse of any order. Regarding the amount of calculations and the complexity of procedures required to derive the transforms of pulse signals, analytically or numerically, this method is more compact and timesaving than conventional methods. When pulse has a much narrow width of equivalently higher the order of several pulses, the method presented here acts to the best of its true merit.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.145-152
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• 2011

Current Bridge Specification for Highway Bridges adopts a simplified method to determine sectional forces of abutment wing by dividing its area into four sections. This simplified method was developed in Japan when numerical analysis was not mature and computer resources were expensive. This simplified method has been with us without modification. This study evaluates the problem of current design practice to improve the design guideline for abutment wing. In this study, a finite element model of abutment wing based on shell elements was developed to obtain accurate sectional force. In addition, foreign design specifications regarding abutment wing were thoroughly examined. It has been observed that sectional forces obtained from the simplified method produce inaccurate results under various geometric shapes. Thus, it is recommended that two dimensional plate analyses should be adopted for future design of abutment wing wall.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.5
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• pp.369-377
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• 1999

Recently, it is gradually raised necessity that thickness of thin film is measured accuracy and managed in industrial circles and medical world. Ultrasonic signal processing method is likely to become a very powerful method for NDE method of detection of microdefects and thickness measurement of thin film below the limit of ultrasonic distance resolution in the opaque materials, provides useful information that cannot be obtained by a conventional measuring system. In the present research. considering a thin film below the limit of ultrasonic distance resolution sandwiched between three substances as acoustical analysis model, demonstrated the usefulness of ultrasonic signal processing technique using information of ultrasonic frequency for NDE of measurements of thin film thickness. Accordingly, for the detection of delamination between the junction condition of boundary microdefect of thin film sandwiched between three substances the results from digital image processing.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.81-93
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• 2012

We propose efficient mobility management schemes based on pointer forwarding for Proxy Mobile IPv6 Networks(PMIPv6) with the objective to reduce the overall network traffic incurred by mobility management and packet delivery. The proposed schemes are per-user-based, i.e., the optimal threshold of the forwarding chain length that minimizes the overall network traffic is dynamically determined for each individual mobile user, based on the user's specific mobility and service patterns. We demonstrate that there exists an optimal threshold of the forwarding chain length, given a set of parameters characterizing the specific mobility and service patterns of a mobile user. We also demonstrate that our schemes yield significantly better performance than schemes that apply a static threshold to all mobile users. A comparative analysis shows that our pointer forwarding schemes outperform routing-based mobility management protocols for PMIPv6.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.67-73
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• 2010

In this paper, a new face detection method that is more accurate than the conventional methods is proposed. This method utilizes a hybrid of Hausdorff distance based on the geometric similarity between the two sets of points and the LBP distance based on the distribution of local micro texture of an image. The parameters for normalization and the optimal blending factor of the two different metrics were calculated from training sample images. Popularly used face database was used to show that the proposed method is more effective and robust to the variation of the pose, illumination, and back ground than the methods based on the Hausdorff distance or LBP distance. In the particular case, the average error distance between the detected and the true face location was reduced to 47.9% of the result of LBP method, and 22.8% of the result of Hausdorff method.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.537-546
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• 1994

The physical characteristics of polymer modified asphalt depend on many parameters, such as, the polymer nature, polymer content and the asphalt properties. The objective of this study is to investigate the temperature susceptibility of polymer modified asphalt. The asphalts employed in this study were two different grades : a soft(200/300) grade and a hard(85/100) grade. And chlorinated polyethylene of two different characteristics were used : plastomer(Tyrin 2552) and elastomer(Tyrin CM0730). Temperature susceptibility of asphalt is a fundamental feature for characterizing asphalt and modified asphalt. It can be quantified by the penetration index(PI) and pen-vis number(PVN). These indices were obtained from the measurements of penetration and viscosity of the asphalt samples. For both of asphalts, the addition of the polymers increases the value of PI and PVN. Plastomer modified asphalt shows higher value of PI and PVN than elastomer modified asphalt. Soft grade shows more temperature susceptibility than hard grade at elevated temperatures.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.3
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• pp.277-289
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• 2011

This study proposes a new testing method for shear bearing capacity of FRP-concrete interface, which could well consider a loading condition corresponding to a tunnel lining undergoing axial compression and could be easily carried out with a simply specified specimen. A parametric study is carried out for capturing an optimized condition of coarse-sand coating of FRP, which governs shear bearing capacity of FRP-concrete interface, by using the proposed testing manner in this study. From the parametric study, it is shown that the proposed testing method is reasonably feasible in comparison with the existing testing methods. An optimum condition of coated sand size and sand density is given for the shearing capacity of FRP-concrete interface.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.427-437
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• 2016

The objective of this study is to develop the regional regression models based on the physiographical and climatological characteristics for estimating flow duration curve (FDC) in ungauged bsisns. To this end, the lower sections with duration from 185 to 355 days of FDCs were constructed from the 16 gauged streamflow data, which were fitted to the two-parameter logarithmic type regression equation. Then, the parameters of the equation were regionalized using the basin characteristics such as basin area, basin slope, drainage density, mean annual precipitation, mean annual streamflow, runoff curve number in order that the proposed regression model can be used for ungauged basin. From the comparison of the estimated by the regional regression model with the observed ones, the model with the combination of basin area, runoff curve number, mean annual precipitation showed the best performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1373-1377
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• 2014

Hot-stamping is a method of obtaining ultrahigh-strength steel by simultaneously forming and cooling boron steel in a press die after it has been heated at $900^{\circ}C$ or above. After heat treatment, boron steel has a strength of 1500 MPa or more. This material ensures a high level of quality because it overcomes the spring-back phenomenon, which is a problem associated with high-strength steel materials, and the degree of dimensional precision is improved by 90 or more because of the good formability compared with existing types of steel. In this study, the welding characteristics were identified through the butt and lap welding of hot-stamped steel using a disk laser. Full penetration was obtained at a faster speed with butt welding compared to lap welding, and a white band was observed in every specimen.