• 한국기계연구소 소보
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• s.18
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• pp.55-66
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• 1988

Many direct integration methods are used for numerical analyses of dynamic motion. In these methods, the governing equations of a dynamic system are integrated successively using a step-by-step numerical integration procedure. Time derivatives in the equations are generally approximated using difference formulas involving one or more increments of the time. Time increment has closely relationship with the accuracy of the motion analysis. In this paper, a 4th order Houbolt direct integration method is derived. For a spring-mass system, the motion of the system are analyzed from the 3rd order Houbolt and the 4th order Houbolt approaches respectively. Finally the paper proposes the optimal time-increment based on the accuracy of numerical analyses.

• Korean Management Science Review
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• v.26 no.3
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• pp.157-167
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• 2009

Technology transition from defense technology to weapon system is an important process for defense acquisition program. Many countries such as USA, UK, Australia and Republic of Korea use technology readiness level (TRL) as a tool for technology transition by identifying critical technology elements (CTEs) and assessing the technology maturity. In this paper we review a transition process for the defense acquisition. Then we suggest a method to evaluate system's TRL using each component TRL and integration readiness level (IRL) between each technologies. We apply the method to an ACTD project. A result show that technology maturity is influenced by integration between technologies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.225-231
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• 2010

As growth of operational complexity in power systems, necessity of information integration between automation systems such as EMS, SAS, DAS and renewable energy sources has been increased. This paper proposes a new information integration architecture between power automation systems based on web service technique. Loosely coupled feature of web service system can provide more flexible and reliable way to exchange information. Communication testing on the demonstration system has been performed to establish the feasibility of the proposed architecture.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.11
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• pp.2804-2811
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• 2000

A Nordsick form opf the multirate integration scheme has been proposed for flexible multibody dynamic systems. It is assumed that vibrational modal coordinates in the equations of motion are treated as fast variables, whereas the relative joint coordinates are treated as slow variables. In the multirate integration, the fast variables are integrated with small step-size, and the slow variables are integrated with larger step-size. The proposed multirate integration method is based on the Adams-Bashforth-Moulton predictor-corrector method and implemented in the Nordsieck vector form. The Nordsieck form of multrate integration method provides effective step-size control and at the same time, inherits the efficiency from the Adams integration method. Simulations of a flexible gun and turret system of the military tank have been carried out to show the effectiveness and efficiency of the proposed method.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.2
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• pp.139-144
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• 2021

In this paper, we described configuration and construction of infrastructure for the KASS Reference Station (KRS), subsystem of Korea Augmentation Satellite System (KASS). KASS system consists of three subsystems(KRS, Mission Control Center (MCC), KASS Uplink Station (KUS)). One of these subsystems, KRS receives GNSS data for generating range error and integrity verification and sends to MCC. It is needed to antenna facilities for mounting GNSS antenna and shelter for operating KRS and infra equipment(power and network system, lightning and grounding system, fire extinguish) for operating KRS. For this reason, we have established the requirements for KRS infrastructure and constructed infrastructure for KRS to meet the requirements of KRS infrastructure.

• The KIPS Transactions:PartD
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• v.18D no.1
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• pp.57-66
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• 2011

Recently, the necessity of new methods of spatial data integration and analysis in CRM has been increased since it is acknowledged that about eighty percent of all data stored in corporate databases has a spatial component. But conventional CRM systems are either incapable of managing spatial data or are not user-friendly when doing so. This paper has designed and implemented spatially-enabled integration management system that can manage consistently both enterprise and spatial data through a legacy CRM system and object-oriented database and additionally support spatial analysis and map visualization for a gCRM. Through implementation, it is demonstrated that the proposed system can facilitate effectively spatial data management and analysis in a legacy CRM system.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.2
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• pp.117-124
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• 2020

In this paper, the symmetric position drift of the integration approach in pedestrian dead reckoning (PDR) system with dual foot-mounted IMU is analyzed. The PDR system that uses the inertial sensor attached to the shoe is called the IA-based PDR system. Since this system is designed based on the inertial navigation system (INS), it has the same characteristics as the error of the INS, then zero-velocity update (ZUPT) is used to correct this error. However, an error that cannot be compensated perfectly by ZUPT exists, and the trend of the position error is the symmetric direction along the side of the shoe(left, right foot) with the IMU attached. The symmetric position error along the side of the shoe gradually increases with walking. In this paper, we analyze the causes of symmetric position drift and show the results. It suggests the possibility of factors other than the error factors that are generally considered in the PDR system based on the integration approach.

• Korean Journal of Remote Sensing
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• v.19 no.1
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• pp.91-97
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• 2003

The design of Graphic Information System(GIS) in various applications is suffering from the difficulty of data acquisition, which is labor-intensive and time consuming. In order to provide the spatial data rapidly and accurately, 4S-Van, a prototype mobile mapping system, has been developed. The 4S-Van consists of 1)Global Positioning System(GPS), Inertial Navigation System(INS) for estimating the geographic position and attitude of the moving van, i.e.,(x, y, z) and the direction of the Van, 2) Charge Coupled Device(CCD) camera and laser scanner for capturing images and for measuring depth from geographic objects, and 3) External Synchronization Device(ESD) and industrial PC for synchronizing data from GPS/INS/CCD camera and for storing the data. In this paper, we present the design and implementation of the proto-Dpe 4S-Van system for spatial data acquisition for various GIS applications.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.103-112
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• 2000

Numerical simulations of unsteady opposed-flow flames are performed using an adaptive time integration method designed for differential-algebraic systems. The compressibility effect is considered in deriving the system of equations, such that the numerical difficulties associated with a high-index system are alleviated. The numerical method is implemented for systems with detailed chemical mechanisms and transport properties by utilizing the Chemkin software. Two test simulations are performeds hydrogen/air diffusion flames with an oscillatory strain rate and transient ignition of methane against heated air. Both results show that the rapid transient behavior is successfully captured by the numerical method.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.247-256
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• 2004

Recently, International Standardization is an important issue in competitive world market because of integration of standard, liberalization of international trade and globalization. Consequently, Korean companies need a strategy about corresponding to market circumstance and global standard. In this study, we examine Intellectual Property, Patent and Antitrust Law which are related to standardization. This study suggests company strategy and system integration model to dispose the global standard.