• Smart Structures and Systems
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• v.30 no.6
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• pp.627-637
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• 2022

Recent years, direct displacement-based design (DDBD) procedure is proposed for the design of un-bonded posttensioned (UPT) concrete wall systems. In the DDBD procedure, the determination of the equivalent viscous damping (EVD) ratio is critical since it would influence the strength demand of the UPT wall systems. Nevertheless, the influence of EVD ratio determination of the UPT wall systems were not thoroughly evaluated. This study was aimed to investigate the influence of different EVD ratio determinations on the DDBD procedure of UPT wall systems. Case study structures with four, twelve and twenty storeys have been designed with DDBD procedure considering different EVD ratio determinations. Nonlinear time history analysis was performed to validate the design results of those UPT wall systems. And the simulation results showed that the global responses of the case study structures were influenced by the EVD ratio determination.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.642-648
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• 2009

Determining the total duration for a construction project is an integral part of project management in the construction industry. This is to ensure the project and all its associated activities can be carried out and completed within the time frame stipulated. There are several commonly used scheduling methods and techniques in project management, some of which involves manual calculation while others involve computer software. This paper looks into the various time determination methods, extracting out their differences and similarities. It also seeks to draw out the problems when determining time for projects, especially those encountered of case studies. Based on the results from the case studies, there were delays on certain projects even though time determination had been carried out rigorously prior to the commencement of the projects. This paper seeks to develop a time determination model, which incorporates risk management techniques into the calculations in order to improve the method for time estimation to minimize the chances of project delay.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.517-524
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• 2004

Two simple and sensitive spectrophotometric methods were developed for the determination of carbocisteine, penicillamine, ethionamide and thioctic acid in bulk and in their pharmaceutical preparations using alkaline potassium permanganate as an oxidizing agent. The first one involves determination of ethionamide and thioctic acid by spectrophotometric investigation of the oxidation reaction of the two drugs. The second method involves determination of carbocisteine and penicillamine by kinetic studies of the oxidation reaction of these two drugs at room temperature for a fixed time of 20 minutes. The absorbance of the colored manganate ions was measured at 610 nm in both methods. 1-10 ${\mu}$g/mL of ethionamide and thioctic acid could be etermined by the spectrophotometric method with detection limits of 0.11 and 0.089 ${\mu}$g/mL for the two drugs respectively. 2-10 ${\mu}$g/mL of carbocisteine and penicillamine could be determined by the kinetic method with detection limits of 0.14 and 0.21 ${\mu}$g/mL respectively. The two methods were successfully applied for the determination of these drugs in their dosage forms.

• Journal of Astronomy and Space Sciences
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• v.31 no.3
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• pp.247-264
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• 2014

In this paper, a brief but essential development strategy for the lunar orbit determination system is discussed to prepare for the future Korea's lunar missions. Prior to the discussion of this preliminary development strategy, technical models of foreign agencies for the lunar orbit determination system, tracking networks to measure the orbit, and collaborative efforts to verify system performance are reviewed in detail with a short summary of their lunar mission history. Covered foreign agencies are European Space Agency, Japan Aerospace Exploration Agency, Indian Space Research Organization and China National Space Administration. Based on the lessons from their experiences, the preliminary development strategy for Korea's future lunar orbit determination system is discussed with regard to the core technical issues of dynamic modeling, numerical integration, measurement modeling, estimation method, measurement system as well as appropriate data formatting for the interoperability among foreign agencies. Although only the preliminary development strategy has been discussed through this work, the proposed strategy will aid the Korean astronautical society while on the development phase of the future Korea's own lunar orbit determination system. Also, it is expected that further detailed system requirements or technical development strategies could be designed or established based on the current discussions.

• The Korean Journal of Applied Statistics
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• v.18 no.2
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• pp.435-443
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• 2005

Coefficients of determination in logistic regression analysis are defined as various statistics, and their values are relatively smaller than those for linear regression model. These coefficients of determination are not generally used to evaluate and diagnose logistic regression model. Liao and McGee (2003) proposed two adjusted coefficients of determination which are robust at the addition of inappropriate predictors and the variation of sample size. In this work, these adjusted coefficients of determination are applied to variable selection method for logistic regression model and compared with results of other methods such as the forward selection, backward elimination, stepwise selection, and AIC statistic.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.29-32
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• 1999

Korea Multi-Purpose SATellite(KOMPSAT) is scheduled to be launched by TAURUS launch vehicle in November, 1999. Tracking, Telemetry and Command(TT&C) operation and the flight dynamics support should be performed for the successful Launch and Early Orbit Phase(LEOP) operation. After the first contact of the KOMPSAT spacecraft, initial orbit determination using ground based tracking data should be performed for the acquisition of the orbit. Although the KOMPSAT is planned to be directly inserted into the Sun- synchronous orbit of 685 km altitude, the orbit maneuvers are required fur the correction of the launch vehicle dispersion. Flight dynamics support such as orbit determination and maneuver planning will be performed by using KOMPSAT Mission Analysis and Planning Subsystem(MAPS) in KOMPSAT Mission Control Element(MCE). The KOMPSAT MAPS have been jointly developed by Electronics and Telecommunications Research Institute(ETRI) and Hyundai Space & Aircraft Company(HYSA). The KOMPSAT MCE was installed in Korea Aerospace Research Institute(KARI) site for the KOMPSAT operation. In this paper, the orbit determination and maneuver planning are introduced and simulated for the KOMPSAT spacecraft in LEOP operation. Initial orbit determination using short arc tracking data and definitive orbit determination using multiple passes tracking data are performed. Orbit maneuvers for the altitude correction and inclination correction are planned for achieving the final mission orbit of the KOMPSAT.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.422-429
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• 1997

For the complete and accurate amino acid determination of protein and food samples, 3 different hydrolysis procedures have been conducted in parallel for each sample, which include the alkaline hydrolysis for tryptophan determination, performic acid oxidation prior to the acid hydrolysis for the determination of cysteine and cystine, and the 6N HCl hydrolysis for the determination of the rest of amino acids. In the present study, amino acid concentrations obtained from the modified single hydrolysis procedure were compared with the values from the conventional hydrolysis procedures in casein and nine food and composite dish samples. In most of the samples tested, the modified single hydrolysis procedure gave significantly higher values of cysteins and cystein compared to the performic acid oxidation method, but resulted in a considerable destruction of tryptophan in food and composited dish samples. There was no consistent difference in the rest of amino acid concentrations between the two hydrolysis systems. Therefore, for complete amino acid determination of various foods and composite dishes, the single hydrolysis method may replace the 6N HCl hydrolysis and performic acid oxidation methods, and thereby reduces 3 hydrolyses to 2 steps with much higher recoveries of the sulfur containing amino acids.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.305-311
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• 2014

Recently, though it was developed several services using the context-awareness technology of IoT, there exist also obstacles for high quality service. Specifically it is short the study for uncertainty of context-awareness. This study focused on understanding the effect of frequency interference among several environmental factors for location determination to increase precision of location determination. It was found that frequency interference between devices using 2.4Ghz frequency effect on the location determination precision. It was resulted that frequency interference increase the error of location determination precision. Then, we confirmed that it was required the suitable compensation method corresponding to frequency interference.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.170-176
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• 2011

This paper analyzes the orbit determination results using azimuth and elevation angle from ground tracking data, which has the standard data interface format, GEOS-C. The ground tracking data is very useful for initial orbit determination after a satellite launch. In this paper, the quality of the measurement data has been investigated using a variety of real tracking passes, compared with the high precision orbit data of KOMPSAT-2. The accumulated tracking data from consecutive satellite-ground passes is processed for orbit determination using least square method. The accuracy of orbit determination result is also presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.251-256
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• 2006

In the work package 'Integrated Positioning' of the research project NAVIO (Pedestrian Navigation Systems in Combined Indoor/Outdoor Environements) we are dealing with the navigation and guidance of visitors of our University. Thereby start points are public transport stops in the surroundings of the Vienna University of Technology and the user of the system should be guided to certain office rooms or persons. For the position determination of the user different location sensors are employed, i.e., for outdoor positioning GPS and dead reckoning sensors such as a digital compass and gyro for heading determination and accelerometers for the determination of the travelled distance as well as a barometric pressure sensor for altitude determination and for indoor areas location determination using WiFi fingerprinting. All sensors and positioning methods are combined and integrated using a Kalman filter approach. Then an optimal estimate of the current location of the user is obtained using the filter. To perform an adequate weighting of the sensors in the stochastic filter model, the sensor characteristics and their performance was investigated in several tests. The tests were performed in different environments either with free satellite visibility or in urban canyons as well as inside of buildings. The tests have shown that it is possible to determine the user's location continuously with the required precision and that the selected sensors provide a good performance and high reliability. Selected tests results and our approach will be presented in the paper.