• Proceedings of the KIEE Conference
• /
• 1993.11a
• /
• pp.151-153
• /
• 1993

This paper proposes a novel motor drive system for the electric vehicle. In this paper, four-wheel-direct-drive type electric vehicle system is designed and the theoretical and experimental analysis of the system is investigated. The concept of steering not with steering the wheels but with the difference of the motor torque fives the flexibility of the vehicle design and, allows the omission of the differential gear, transmission gear, and drive axles. Thus the proposed system gives the space between wheels and improves the driver's steering performance.

• Proceedings of the KIEE Conference
• /
• 1992.07a
• /
• pp.245-247
• /
• 1992

We utilize as a processor TMS320C25 (Texas Instrument) in making a driver for a 4 pole PM synchronous servo motor. TMS320C25 has a 32bit ALU and a 16 bit hardware multiplier, and the maximum instruction execution rate is 10MIPS at 40MHz. We adopted a space vector modulation PWM method. An interesting point of this work is that PWM wave is generated by utilizing timer interrupts. Hence, in the rest of time the processor can take care of the other routine such as Park's coordinate transformation and the computation required in the feedback loops. Thus, it mates the hardware circuit very simple. Due to the decrease in the number of components, the motor drive system becomes more fault-tolerant and cost-optimized. Also, more flexibility is gained in changing the control parameters.

• ETRI Journal
• /
• v.22 no.1
• /
• pp.1-11
• /
• 2000

The Satellite Operation System (SOS) has been developed for a low earth orbiting remote sensing satellite, Korea Multipurpose Satellite-I, to monitor and control the spacecraft as well as to perform the mission operation. SOS was designed to operate on UNIX in the HP workstations. In the design of SOS, flexibility, reliability, expandability and interoperability were the main objectives. In order to achieve these objectives, a CASE tool, a database management system, consultative committee for space data systems recommendation, and a real-time distributed processing middle-ware have been integrated into the system. A database driven structure was adopted as the baseline architecture for a generic machine-independent, mission specific database. Also a logical address based inter-process communication scheme was introduced for a distributed allocation of the network resources. Specifically, a hotstandby redundancy scheme was highlighted in the design seeking for higher system reliability and uninterrupted service required in a real-time fashion during the satellite passes. Through various tests, SOS had been verified its functional, performance, and inter-face requirements. Design, implementation, and testing of the SOS for KOMPSAT-I is presented in this paper.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.5
• /
• pp.9-18
• /
• 1998

The components with J-lead. which are more integrated and smaller than ones with Gull-wing. are rapidly being used in electronic board such as the PCB, for they have the advantage of occupying a small space compared to the other components. However, the development of inspection system for these new components is not so rapid as component development. Component-inspection with J-lead using vision system is difficult because they are hidden from camera optical axis. X-ray inspection, which has the advantage of inspecting the inside of solder state, is used to J-lead inspection. However. it is high cost and dangerous by leaking out X-ray compared to vision system. Therefore, in this paper, we design vision system suited to J-lead inspection and then propose algorithm which have flexibility in mount and rand error.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2004.05a
• /
• pp.176-183
• /
• 2004

Deployable structures are space frames consisting of straight bars that are linked together into bundle and can be deployed large, load bearing structures. Deployable structures are easy to set up, to assemble, to disassemble, to transport and to keep for the use. Also, reusability and flexibility are another important advantages for environmental matter. Since deployable structures have various advantages, they offer viable alternatives for a wide range of potential applications in the temporary construction industry as well as in the aerospace industry. The purpose of this thesis is to decide on geometrical parameters of the design through the numerical analysis and create a final configuration of deployable structures using the geometrical parameters. The Multibody Dynamic Analysis that is dealt with mechanics and aeronautics is used for the method of analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1133-1138
• /
• 2000

This paper describes a signal recognition method for diagnosing the rotating machinery using wavelet-aided Self-Organizing Feature Map(SOFM). The SOFM specialized from neural network is a new and effective algorithm for interpreting large and complex data sets. It converts high-dimensional data items into simple order relationships with low dimension. Additionally the Learning Vector Quantization(LVQ) is used for reducing the error from SOFM. Multi-resolution and wavelet transform are used to extract salient features from the primary vibration signals. Since it decomposes the raw timebase signal into two respective parts in the time space and frequency domain, it does not lose either information unlike Fourier transform. This paper is focused on the development of advanced signal classifier in order to automatize vibration signal pattern recognition. This method is verified by the experiment and several abnormal vibrations such as unbalance and rubbing are classified with high flexibility and reliability by the proposed methods.

• Journal of the Korea Concrete Institute
• /
• v.12 no.4
• /
• pp.113-119
• /
• 2000

The R/C flat plate system provides architectural flexibility, clear space, reduced building height, simple formwork, which consequently enhance constructibility. One of the serious problems in the flat plate system is brittle punching shear failure due to transfer of shear force and unbalanced moments in column-slab joint. Recently, the flat plate system accompanied with shear walls to resist the lateral loads is applied to high-rise buidings. Although the flat plate system is not considered in design as part of the lateral load-resisting system, it is required that this system keeps the ductile behavior for the lateral displacement of the building. However, it is unclear whether the column-slab joint possesses ductility enough to survive the lateral deformation. The objective of this paper is to investigate the major parameters that influence the ductility of R/C flat plate system by examining the existing experiments on column-slab joint. The effects of gravity load and shear reinforcement on the ductility of the flat plate system are presented.

• Korean Journal of Child Studies
• /
• v.22 no.2
• /
• pp.219-235
• /
• 2001

The purpose of this study was to provide guidelines for the effective operation of Web-Based Training (WBT) for early childhood teachers. Based on content analysis and questionnaires administered to the 174 current trainees, this research analyzed (1) the educational effectiveness and learner satisfaction, (2) the operation and management, and (3) the system, interface, interaction and communication, motivation and content design of $WBT^{***}$. Results showed that most trainees were very satisfied with the WBT because the program provided plentiful professional information enabling them to pursue their educational objectives along with flexibility of time and space. On the other hand, system stability, communication, motivation, and content design need to be improved. Based on the research results, 8 strategies of effective management of web-based early childhood teacher training were proposed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.18 no.1
• /
• pp.21-27
• /
• 2012

We can efficiently collect crops or minerals by operating multi-robot foraging. As foraging spaces become wider, control algorithms demand scalability and reliability. Swarm robotics is a state-of-the-art algorithm on wide foraging spaces due to its advantages, such as self-organization, robustness, and flexibility. However, high initial and operating costs are main barriers in performing multi-robot foraging system. In this paper, we propose a novel method to improve the energy efficiency of the system to reduce operating costs. The idea is to employ a new behavior model regarding role division in concert with the search space division.

• The KIPS Transactions:PartA
• /
• v.8A no.2
• /
• pp.91-98
• /
• 2001

TCP/IP based remote system using internet presented the method to access and control all the types of resources connected to network system over time and space. In this paper, We studied a resource control method through a mutual communication of a system association composed of service user, provider, and manager of the network system for the web based remote control system. The service users require the resources, and its providers are a variety of devices and digital electronic products which can provide the services in a network system. The service manager who operates the whole system performs the role to interconnect its users with its providers. Through an experiment, an implemented system confirmed flexibility, stability, and extensibility of the method presented in this paper.