• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1185-1186
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• 2007

The UTM-01 developed in 1998 was the first maglev vehicle in Korea for the urban transit maglev (UTM) system. Through the improvement of UTM-01 and development of UTM02, the commercialization of the UTM system is being prepared now. In order to prepare for the commercialization of maglev, it is necessary that an optimal design of the levitation magnet should be provided for the safe operation of the vehicle. The levitation force is formed through the function of magnetic flux density on the top of magnet poles and gap between magnet pole and guide rail. To generate a magnetic field that is high enough to levitate the vehicle, ferromagnetic materials, such as pure iron for magnet pole and SS400 for guide rail, were used. The heat generated by $I^2R$ loss of magnet conductor makes the thermal convection on the surface of magnet including coil and poles. As these two characteristics are nonlinear phenomena, this paper deals with the nonlinear analysis on the magnetic and thermal properties of the U-type levitation magnet by using 3-D finite element method (FEM). Base on the analysis results, a small scale U-type magnet was designed, manufactured, and tested and it was verified that the magnet manufactured was satisfactory to all the design specifications.

• Journal of Internet Computing and Services
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• v.17 no.5
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• pp.67-74
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• 2016

Distributed agile software development faces difficulties for instance lack of visibility across development and delivery processes, complex and disjointed development processes, inability to capitalize on business opportunities, lack of communication agility between disconnected owners, development teams, and users or clients. However these difficulties are solved with the help of cloud computing services. This study proposes a framework to provide a skeletal or structural environment for distributed agile software development in cloud computing environment. The framework guide towards the best tooling to deliver a consistent, automated, governed, and unified agile software development process with reduced technical debt, and minimized project backlog. In addition to this, the study highlights the benefits of cloud computing in agile software development.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.173-181
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• 2020

This study examines whether unmanned aircraft systems (UAS) operated in the context of UAS traffic management (UTM) can be properly operated in its flight environment. In detail, this study examines the influencing navigation factors affecting UASs during flight and examines factors affecting the navigation of UASs under UTM. After deriving various factors affecting navigation, their importance are determined by applying the analytic hierarchy process technique, and the important influencing factors are examined. For low-altitude UAS navigation, errors are classified into navigation-system and flight-technical errors, and a hierarchy is constructed for their sub-factors affecting the influencers. Through this, influencing factors for precise navigation of low-altitude UAS are analyzed, and high importance items are identified.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1569-1584
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• 2013

Ubiquitous interaction in a pervasive environment is the main attribute of smart spaces. Pervasive systems are weaving themselves in our daily life, making it possible to collect user information invisibly, in an unobtrusive manner by known and even unknown parties. Huge number of interactions between users and pervasive devices necessitate a comprehensive trust model which unifies different trust factors like context, recommendation, and history to calculate the trust level of each party precisely. Trusted computing enables effective solutions to verify the trustworthiness of computing platforms. In this paper, we elaborate Unified Trust Model (UTM) which calculates entity's trustworthiness based on history, recommendation, context and platform integrity measurement, and formally use these factors in trustworthiness calculation. We evaluate UTM behaviour by simulating in different scenario experiments using a Trust and Reputation Models Simulator for Wireless Sensor Networks. We show that UTM offers responsive behaviour and can be used effectively in the low interaction environments.

• 연구논문집
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• s.27
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• pp.5-13
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• 1997

Test results of urban transit maglev system(UTM-01) are reported. Maglev project team in KIMM, in cooperation with Hyundai Precision Company and the Korea Electric Research Institute(KERI), has been developing a prototype urban transit vehicle since 1995. Since last May, we have been trying to improve performance of the first vehicle UTM-01 both in levitation and propulsion systems. In this paper, we report various test results of the vehicle UTM-01, present status and future prospect, and what have been done so far to assure its required performance.

• 기계와재료
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• v.11 no.2 s.40
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• pp.111-118
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• 1999

Test Results and Status of development of the urban transit maglev system(UTM-O1) are reported. Maglev Project Team in KIMM, in cooperation with Hyundai Precision Company and the Korea Electrotechnology Research Institute(KERI), has successfully finished the second stage development project (1995. 5-1998. 8) and demonstrated a prototype two vehicle consisted urban maglev train operating in the speed range of 50km/h. In this paper, we report various test results of the UTM-01 system, present status of quo and future prospect, and what have been done so far to improve the performance of the maglev system overall.

• Proceedings of the KSR Conference
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• 2006.11a
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• pp.219-227
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• 2006

Since the Maglew ehicle is run over an elevated guideway, the types of guideways affect the running behavior of the vehicle and guideway. The design of a guideway has a strong effect on the costs of constructing guideways, the optimized design of a guideway satisfying running performance is needed for the commercialization of the Maglew vehicle. With an analysis program for dynamics of Maglew vehicles, the dynamic responses of the UTM01 and guideway are numerically analyzed according to types of guideway.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.802-809
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• 2010

KIMM(Korea Institute of Machinery and Materials ) and ROTEM have been leading development of the low to medium speed urban transit maglev for the past 20 years. The result of this long term national project is UTM-01 ( Urban Transit Maglev -01 ) in 1998 and UTM-02 in 2006 and the 6.1 km long double track maglev commercialization project in Inchon international airport from 2006 to 2012. In this paper the status of the maglev development for the past 20 years is reported. Design changes in key technologies - maglev bogies, secondary suspension system, levitation system, propulsion system, major power suppling equipments from UTM-01 system to that of commercialization project - are described.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.291-295
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• 2007

The irregularities in the guideways used in the Maglev transportation system that result from surface roughness and deflection of guideway have strong effects on the dynamic characteristics of Maglev vehicles, because the electromagnetic suspension of Maglev vehicles strongly interacts with the guideway. For this reason, a numerical prediction of air gap responses to these irregularities is desirable to improve aspects of running performance, such as stability and passenger comfort, while minimizing aesthetic impact and construction cost. This paper presents a procedure to predict the air gap response which is a criteria for stability, and investigates the responses with the goal of attaining higher travel speeds in the urban Maglev vehicle UTM-01 utilizing electromagnetic suspension.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.118-126
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• 2008

The levitation stability of a Maglev vehicle utilizing electromagnetic suspension is primarily influenced by the deformation, roughness, and vibration of the guideway. Optimum design for both the vehicle and the guideway is desirable in order to reduce guideway construction cost, while meeting requirements for stability and ride quality. This paper presents an analysis of the levitation stability of the UTM-01, an urban Maglev vehicle, using a numerical simulation. The ODYN/Maglev, a dynamics analysis program, is used to simulate dynamics to evaluate the stability. A running test of the UTM-01 is also carried out to verify the results of the simulation. Using the simulation results, the levitation stability of the UTM-01 can be numerically analyzed at a variety of vehicle speeds.