• International Journal of Aeronautical and Space Sciences
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• v.13 no.3
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• pp.377-385
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• 2012

The Automatic Dependent Surveillance Broadcast (ADS-B) system is a key component of CNS/ATM recommended by the International Civil Aviation Organization (ICAO) as the next generation air traffic control system. ADS-B broadcasts identification, positional data, and operation information of an aircraft to other aircraft, ground vehicles and ground stations in the nearby region. This paper explores the ADS-B based trajectory prediction and the conflict detection algorithm. The multiple-model based trajectory prediction algorithm leads accurate predicted conflict probability at a future forecast time. We propose an efficient and accurate algorithm to calculate conflict probability based on approximation of the conflict zone by a set of blocks. The performance of proposed algorithms is demonstrated by a numerical simulation of two aircraft encounter scenarios.

• Journal of Korea Water Resources Association
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• v.37 no.1
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• pp.67-75
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• 2004

In this study, real-time forecasting model(Neural Dam Inflow Forecasting Model; NDIFM) based on neural network to predict the dam inflow which is occurred by flood runoff is developed and applied to check its availability for the operation of multi-purpose reservoir Developed model Is applied to predict the flood Inflow on dam Nam-Gang in Nak-dong river basin where the rate of flood control dependent on reservoir operation is high. The input data for this model are average rainfall data composed of mean areal rainfall of upstream basin from dam location, observed inflow data, and predicted inflow data. As a result of the simulation for flood inflow forecasting, it is found that NDIFM-I is the best predictive model for real-time operation. In addition, the results of forecasting used on NDIFM-II and NDIFM-III are not bad and these models showed wide range of applicability for real-time forecasting. Consequently, if the quality of observed hydrological data is improved, it is expected that the neural network model which is black-box model can be utilized for real-time flood forecasting rather than conceptual models of which physical parameter is complex.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.3
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• pp.96-105
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• 1992

The use of fixed-point digital signal processors, such as the TMS 320C25, requires scaling of data at each arithmetic step to prevent overflows while keeping the accuracy. A software which automatizes this process is developed for TMS 320C25. The programmers use a model of a hypothetical floating-point digital signal processor and a floating-point format for data representation. However, the program and data are automatically translated to a fixed-point version by this software. Thus, the execution speed is not sacrificed. A fixed-point variable has a unique binary-point location, which is dependent on the range of the variable. The range is estimated from the floating-point simulation. The number of shifts needed for arithmetic or data transfer step is determined by the binary-points of the variables associated with the operation. A fixed-point code generator is also developed by using the proposed automatic scaling software. This code generator produces floating-point assembly programs from the specifiations of FIR, IIR, and adaptive transversal filters, then floating-point programs are transformed to fixed-point versions by the automatic scaling software.

• Journal of Distribution Science
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• v.14 no.10
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• pp.93-107
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• 2016

Purpose - This study aims to derive directions and implications for improving performance in operating agrifood export organizations by identifying significant performance impact factors. Research design, data, and methodology - A seemingly unrelated regression (SUR) model was estimated using data from a survey conducted among 120 exporters including 16 leading export organizations. In the SUR estimation, the export volume and price are used as dependent variables and securing the quantity of products ordered and exported, quality management, and marketing activities are considered as explanatory variables for the operation performance. Results - The amount of farmer education, the manpower in charge of marketing, and the interaction terms between whether or not they belong to a leading export organization and the item dummy for mushrooms have a significant impact on the export volume where the export volume is specified as a dependent variable. The export volume is greater with a greater amount of farmer education and greater manpower in charge of marketing from the perspective of quality management. When the export price is estimated as a dependent variable, the manpower in charge of marketing is shown to have a significant impact on the export price. Conclusions - The government needs to strengthen its support of the performance of agrifood export organizations. The analysis indicates that the education of and consulting with farmers, and the manpower number in charge of marketing are key factors in the operation performance of export organizations. Therefore, supporting the export organizations in expanding their human resources in charge of marketing can increase the export volumes for agrifoods. Given, however, that the export volume associated with joint payments, human resources specialized in quality management, and the amount of participation in export exhibitions are not significant factors, it is essential to improve the supporting policies for those areas. The manpower in charge of marketing from the perspective of marketing has a significant impact on both the export volume and export price. Thus, we identify this as the most important category that should be supported to enhance performance in export organizations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.4
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• pp.274-280
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• 2001

This paper presents transconductance (g$\_$m/( characteristics of GaAs MESFET's at high temperatures ranging from room temperature to 350$\^{C}$. GaAs MESFET of 0.3x750[㎛] gate dimension has been used to obtain the experimental data. Gate to source voltage(V$\_$GS/) has been controlled to obtain the temperature dependent characteristics for maximum transconductance g$\_$mmax/ of the device. Furthermore g$\_$mmax/ and expected g$\_$m/ have been traced with temperatures ranging from room temperature to 350$\^{C}$ also by compensating for C$\_$GS/ to maintain the optimum operation of the device. From the results, V$\_$GS/decreases as the operating temperature increases for optimum operation of the transconductance. Finally V$\_$GS/ has been optimized to trace g$\_$mmax/ and enhances the decreased g$\_$m/ with different temperatures.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.2
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• pp.26-31
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• 2012

A new operational concept for the CNS/ATM using the digital data communication technology and satellite navigation system is being implemented globally and the United States is the first country to apply UAT ADS-B system for general aviation. Korea also has plan to build ADS-B system for aeronautical surveillance to monitor low altitude flight of light aircraft and ultra-light flying device and the research to develop UAT ADS-B equipment is being carried out. This paper presents the application method of UAT ADS-B to support test operation with case study of foreign UAT ADS-B operation and survey of domestic environment.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.505-508
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• 2000

The success of target reconstruction in SAR(Synthetic Aperture Radar) imaging system is greatly dependent on the coherent detection. Primary causes of incoherent detection are uncompensated target or sensor motion, random turbulence in propagation media, wrong path in radar platform, and etc. And these appear as multiplicative phase error to the echoed signal, which consequently, causes fatal degradations such as fading or dislocation of target image. In this paper, we present iterative phase error estimation scheme which uses echoed data in all temporal frequencies. We started with analyzing wave equation for one point target and extend to overall echoed data from the target scene - The two wave equations governing the SAR signal at two temporal frequencies of the radar signal are combined to derive a method to reconstruct the complex phase error function. Eventually, this operation attains phase error correction algorithm from the total received SAR signal. We verify the success of the proposed algorithm by applying it to the simulated spotlight-mode SAR data.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.2027-2032
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• 2005

This paper demonstrates details of thermal behavior of Langmuir-Blodgett (LB) film of poly(tert-butyl methacrylate) (PtBMA) by using the principal component analysis based two-dimensional correlation spectroscopy (PCA2D) through eigenvalue manipulating transformation (EMT). By uniformly lowering the power of a set of eigenvalues associated with the original data, the smaller eigenvalues becomes more prominent and the subtle contribution from minor components is now highlighted much more strongly than the original data. Thus, the subtle difference of thermal behavior of LB film of PtBMA from minor components, which is not readily detectable in the conventional 2D correlation analysis, is much more noticeable than the original data. PCA2D correlation spectra with EMT operation for the temperature-dependent IR spectra of LB film of PtBMA reveal the hidden property of phase transition processes during heating.

• Corrosion Science and Technology
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• v.5 no.3
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• pp.99-105
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• 2006

This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.343-352
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• 2020

Purpose: This study identifies the impact on composition of the firefighting organization, fire command ability, and public opinion operation on organizational citizenship behavior for fire officials to respond to the earthquake disaster, and provides practical implications as basic data for firefighting organizations to cope with the earthquake disaster. Method: Questionnaire survey was performed for 159 fire officials, and the surveyed data was statistically analyzed by using SPSS 22.0 program. Result: First, the results of the verification of the hypothesis showed that the composition of the fire organization, firefield command ability and public opinion operation have a positive impact on organizational citizenship behavior. Second, the relative contribution of independent variables to the dependent variables was identified in the order of composition of fire organization, fire command ability and public opinion operation. Conclusion: The implications of this study suggested from a practical perspective that the government needs to organize firefighting organizations, develop firefield command ability and operate public opinion in advance in order to respond to earthquakes.