• Journal of Power Electronics
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• v.15 no.4
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• pp.1054-1065
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• 2015

Multi-functional voltage source inverters (VSIs) have attracted increasing attention in recent years for their advantageous auxiliary services for power quality enhancement in autonomous microgrids. These types of VSIs can not only achieve a proper control scheme in autonomous mode but also cope with the prescribed power quality and stability requirements. These functionalities are integrated within the same device, thereby significantly improving the cost-effectiveness of microgrids while decreasing the investment and bulk compared with those of multiple devices with independent functionalities. Control strategies for power quality enhancement in autonomous microgrids using multi-functional VSIs are comprehensively reviewed in this paper. In addition, such VSIs are discussed in detail, and comparisons of which are also provided. Lastly, a number of future research directions for multi-functional VSIs are recommended.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.335-338
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• 2005

In this paper, we propose a downlink power control scheme to apply in the unequal error protection multi-code CDMA mobile medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1376-1379
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• 2004

This study is designed integration and control system of GaAs bonding system consisted of multi-processing using DeviceNet and GEM-Protocol. Developing bonding system is composed of resin coating, pre-baking pre-aligner, bonding, material handler(flip robot), and wafer cassette, etc. This system has process-fluent of each a process and share information using GEM-protocol. This study devised virtual bonding simulator to control and to monitor bonding system efficiently. Also we can verify optimizing of system previously through a virtual bonding simulator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.699-701
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• 2010

For the development of surveillance Multi Sensor and IFOG, development of integrated surveillance camera for day and night time of its system Control Unit design and navigation device interlocking system was made. Control Unit analysis of integrated ship system began with selection of control unit related to feasible navigation device list.After sorting navigation equipment list, applications, features, connection methods, communication methods, data type of control unit and data direction between navigation equipments and the data types of each navigation equipment is sorted to observe its performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.965-966
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• 2009

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3423-3438
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• 2014

In recent years, wearable sensor devices are reshaping the way people live, work, and play. A wearable sensor device is a computer that is subsumed into the personal space of the user, and is always on, and always accessible. Therefore, among the most salient aspects of a wearable sensor device should be a small form factor, long battery lifetime, and real-time characteristics. Thereby, sophisticated applications of a wearable sensor device use real-time operating systems to guarantee real-time deadlines. The deterministic multi-dimensional task scheduling algorithms are implemented on ARC (Actual Remote Control) with relatively limited hardware resources. ARC is a wearable wristwatch-type remote controller; it can also serve as a universal remote control, for various wearable sensor devices. In the proposed algorithms, there is no limit on the maximum number of task priorities, and the memory requirement can be dramatically reduced. Furthermore, regardless of the number of tasks, the complexity of the time and space of the proposed algorithms is O(1). A valuable contribution of this work is to guarantee real-time deadlines for wearable sensor devices.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.3
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• pp.185-190
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• 2022

We propose a high speed data communication method for motor drive systems with fast control cycle in order to collect state variables of motor control without degrading control performance. Ethernet is chosen for communication device, and multi-core DSP architecture is exploited for communication processing load distribution. The communication program including network protocol stack and motor control program are assigned to two separate cores, and data between two cores are exchanged using interrupt-based inter-process communication mechanism, which enables to achieve a high-speed communication performance without degrading the motor control performance. The performance of developed communication method is demonstrated by real experiments using TCP, UDP and Raw Socket protocols in an experimental setup consisting of TI's TMS320F28388D motor control card and MS Windows PC.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.31-40
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• 2021

The multi-channel video streaming system is an essential device for future ground combat vehicles. For the system, the application of digital interfaces is required instead of the direct analog method to support selectable multiple channels. However, due to the characteristics of the digital interfaces that require en/decoding and signal conversion, the system should support the ability to adapt to quality and delay requirements depending on how video data is utilized. To support addressed issue, this study designs and emulates the multi-channel compressed-video streaming system of ground combat vehicle's fire control system based on commercial standards. Using the system, this study analyzes the quality of video according to the rotational speed of the acquisition device and Glass-to-Glass (G2G) delay between video acquisition and display devices according to video compression rates. Through these experiments and analysis, this paper presents the design direction of the system having scalability on the latest technology while providing high-quality video data streaming flexibly.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.69-77
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• 2013

When structural design of a tall building is conducted, reduction of wind-induced lateral displacement is one of the most important problem. For this purpose, additional dampers and vibration control devices are generally considered. In this process, control performance of additional devices are usually investigated for optimal design without variation of characteristics of a structure. In this study, multi-objective integrated optimization of structure-smart control device is conducted and possibility of reduction of structural resources of a tall building with additional smart damping device has been investigated. To this end, a 60-story diagrid building structure is used as an example structure and artificial wind loads are used for evaluation of wind-induced responses. An MR damper is added to the conventional TMD to develop a smart TMD. Because dynamic responses and the amount of structural material and additional smart damping devices are required to be reduced, a multi-objective genetic algorithm is employed in this study. After numerical simulation, various optimal designs that can satisfy control performance requirement can be obtained by appropriately reducing the amount of structural material and additional smart damping device.

• International journal of steel structures
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• v.18 no.5
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• pp.1598-1606
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• 2018

An integrated optimal structural design method for a diagrid structure and control device was developed. A multi-objective genetic algorithm was used and a 60-story diagrid building structure was developed as an example structure. Artificial wind and earthquake loads were generated to assess the wind-induced and seismic responses. A smart tuned mass damper (TMD) was used as a structural control system and an MR (magnetorheological) damper was employed to develop a smart TMD (STMD). The multi-objective genetic algorithm used five objectives including a reduction of the dynamic responses, additional stiffness and damping, mass of STMD, capacity of the MR damper for the integrated optimization of a diagrid structure and a STMD. From the proposed method, integrated optimal designs for the diagrid structure and STMD were obtained. The numerical simulation also showed that the STMD provided good control performance for reducing the wind-induced and seismic responses of a tall diagrid building structure.