• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.8
• /
• pp.122-131
• /
• 2011

In this paper, the design and analysis of a reconfigurable modular structure, which reforms itself according to the change of the environment and realize appropriate forms and motions, are dealt with. This modular is a free structure from the restrictions with constraints about fixed environment and has various forms and motions by combining units. The form of this unit has a shape of a square with 7 centimeters side each, and has a structure which can be combined in a chain-shape or a lattice-shape. Additionally, The structure has a mobility by being equipped with wheels so that it can be combined for itself. In this paper, all the wireless controllers, sensor system, and communicating method between modules according to module structures were suggested and transformation method to be transformed to shape of snakes, caterpillars were presented. Moreover, simulations for each method were performed to show the validity of the motions including motor torque analysis. All the motions suggested were realized and experimented, whereby the availability of the designed mechanism and algorithm was verified with the result of experiments.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.201-202
• /
• 2012

This paper presents a simple and cost-effective stand-alone rapid battery charging system of 30kW for electric vehicles. The proposed system mainly consists of active front-end rectifier of neutral point clamped 3-level type and non-isolated bi-directional dc-dc converter of multi-phase interleaved half-bridge topology. The charging system is designed to operate for both lithium-polymer and lithium-ion batteries. The complete charging sequence is made up of three sub-interval operating modes; pre-charging mode, constant-current mode, and constant-voltage mode. Each mode is operated according to battery states: voltage, current and State of Charging (SOC). The proposed system is able to reach the full-charge state within less than 16min for the battery capacity of 8kWh by supplying the charging current of 67A. The optimal discharging algorithm for Vehicle to the Grid (V2G) operation has been adopted to maintain the discharging current of 1C. Owing to the simple and compact power conversion scheme, the proposed solution has superior module-friendly mechanical structure which is absolutely required to realize flexible power expansion capability in a very high-current rapid charging system. Experiment waveforms confirm the proposed functionality of the charging system.

• Journal of Korea Multimedia Society
• /
• v.19 no.8
• /
• pp.1337-1344
• /
• 2016

As the visual effect frequently used in movies or animations, special effects are well suited for the creation of buildings or materials' destruction and collapse scenes. With the relevant programs developing technologically, the adoption of a real-time physically based-system makes it possible to realistically express dynamic simulations. In the large scale, the visual expression of such effects of destroying is satisfying enough, but most common programs of those effects fail to maximize visual effect generated with the cutting of small materials. Besides, to perform a heavy simulation process needs high-performance hardware and programs, where high costs would become a serious issue. For this reason, this paper suggests a solution optimized for the effect of small materials-cutting. The progress of each step shows technologies which trace movement with the state of the completion of the character's motions and then cut the material in real-time, finally led to the very realistic visual effect. Besides, using vector inner calculation to follow the motions of object and to realize cutting effect, this study provides an experiment that constructs visual effect for visualization from the basis of mathematical algorithm and it would be certainly as an educational material used for further researches.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.9
• /
• pp.4307-4325
• /
• 2016

With the aim of solving the problems of long processing times, high memory consumption and low event throughput in the current processing approaches in out-of-order RFID event streams, an efficient complex event processing method based on INFA-HTS (Improved Nondeterministic Finite Automaton-Hash Table Structure) is presented in this paper. The contribution of this paper lies in the fact that we use INFA and HTS to successfully realize the detection of complex events for out-of-order RFID event streams. Specifically, in our scheme, to detect the disorder of out-of-order event streams, we expand the traditional NFA model into a new INFA model to capture the related RFID primitive events from the out-of-order event stream. To high-efficiently manage the large intermediate capturing results, we use the HTS to store and process them. As a result, these problems in the existing methods can be effectively solved by our scheme. The simulation results of our experiments show that our proposed method in this paper outperforms some of the current general processing approaches used to process out-of-order RFID event streams.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1780-1783
• /
• 2005

In this paper ZMP was considered in order to get a walking stability, so the gait in the stable domain was realized through putting the stability margin in the sole domain of a foot. It is assumed that the robot's legs have 12 joints to operate a open-loop drive and there was no external disturbance under walking phases, additionally, the robot is walking on the flat plane. It was observed that the robot's walking trajectory, locus of COM and ZMP after imposing the motion to each joint. For realizing the simulation considering ZMP and movement of mass center, it was checked if it is stable for the constraint robot model to walk in stability and the feasibility was estimated about its dynamic gait. Eventually it was shown that a constraint gait algorithm is able to realize. To verify the proper walking process, ZMP(Zero Moment Point) theory is applied and the simulation has been done by ADAMS.

• International Journal of Control, Automation, and Systems
• /
• v.4 no.4
• /
• pp.405-413
• /
• 2006

A novel approach based on genetic algorithms (GA) is developed to find a global minimum-jerk trajectory of a space robotic manipulator in joint space. The jerk, the third derivative of position of desired joint trajectory, adversely affects the efficiency of the control algorithms and stabilization of whole space robot system and therefore should be minimized. On the other hand, the importance of minimizing the jerk is to reduce the vibrations of manipulator. In this formulation, a global genetic-approach determines the trajectory by minimizing the maximum jerk in joint space. The planning procedure is performed with respect to all constraints, such as joint angle constraints, joint velocity constraints, joint angular acceleration and torque constraints, and so on. We use an genetic algorithm to search the optimal joint inter-knot parameters in order to realize the minimum jerk. These joint inter-knot parameters mainly include joint angle and joint angular velocities. The simulation result shows that GA-based minimum-jerk trajectory planning method has satisfactory performance and real significance in engineering.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.583-585
• /
• 2016

The recent advances in wireless networks area have led to new techniques, such as small cells or full-duplex (FD) transmission, have also been developed to further increase the network capacity. Particularly, full-duplex communication promises expected throughput gain by doubling the spectrum compared to half-duplex (HD) communication. Because this technique permits one set of frequencies to simultaneously transmit and receive signals. In this paper, we focus on the binary power control for the users and the base stations in full-duplex multiple cellulars wireless networks to obtain optimal sum-rate under the effect interference and noise. We investigate with a scenario in there one carrier is assigned to only one user in each cell and construct a model for this problem. In this work, we apply the binary power control by the its simplification in the implemented algorithm for both uplink and downlink simultaneously to maximize sum data rate of the system. At first, we realize the 2-cells case separately to check the optimal power allocation whether being binary. Then, we carry on with N-cells case in general through properties of binary power control.

• Journal of Mechanical Science and Technology
• /
• v.19 no.12
• /
• pp.2213-2223
• /
• 2005

In order to reconstruct a full 3D human model in reverse engineering (RE), a 3D scanner needs to be placed arbitrarily around the target model to capture all part of the scanned surface. Then, acquired multiple scans must be registered and merged since each scanned data set taken from different position is just given in its own local co-ordinate system. The goal of the registration is to create a single model by aligning all individual scans. It usually consists of two sub-steps: rough and fine registration. The fine registration process can only be performed after an initial position is approximated through the rough registration. Hence an automated rough registration process is crucial to realize a completely automatic RE system. In this paper an automated rough registration method for aligning multiple scans of complex human face is presented. The proposed method automatically aligns the meshes of different scans with the information of features that are extracted from the estimated principal curvatures of triangular meshes of the human face. Then the roughly aligned scanned data sets are further precisely enhanced with a fine registration step with the recently popular Iterative Closest Point (ICP) algorithm. Some typical examples are presented and discussed to validate the proposed system.

• Journal of the Korean Institute of Telematics and Electronics T
• /
• v.36T no.3
• /
• pp.64-71
• /
• 1999

In this paper, two degree of freedom parallelogram link mechanism is used as DD(Direct-drive) robot mechanism. In parallelogram link mechanism, two motors being established in each base frame, the mass of motor itself is not loaded to anther motor; the number of links are increased, the mass of arm being lighter; with the estabilishment of link parameter, nonlinearity such as the centrifugal force disappears; at the same time anti-interference between motors can be realized. And to realize highy-accurate drive of parallelogram link DD robot manipulator, to improve the learning speed through the design of leaning control system using neural network, to raise adapting power to the varied work objects; the learning control algorithm is composed of neural network and feedback controller in this paper.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.1
• /
• pp.75-82
• /
• 2014

For accurate gain tuning of the lab-manufactured six-axis articulated robot RS2 with less noise, in this study, a program routine using dynamic signal analyzer, which is a realization of a controller design algorithm in the frequency domain, is programmed using LabVIEW$^{(R)}$. The contribution of this paper is the proposal of a simulation technique based on SolidWorks$^{(R)}$ and LabVIEW$^{(R)}$ for the gain tuning of a six-axis articulated robot. To realize the simulation, the LabVIEW$^{(R)}$ program used for experimental gain tuning is incorporated in to SolidWorks$^{(R)}$. A comparison shows that the results of simulation-based gain tuning and experimental gain tuning are almost the same within a 5% error bound. On the basis of the comparison, it can be suggested that the simulation-based technique for gain tuning can be applied instead of experimental gain tuning to a six-axis articulated robot by interlocking SolidWorks$^{(R)}$ and LabVIEW$^{(R)}$.