• The Journal of Korea Robotics Society
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• v.7 no.2
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• pp.120-128
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• 2012

The loop closure problem is one of the most challenging issues in the vision-based simultaneous localization and mapping community. It requires the robot to recognize a previously visited place from current camera measurements. While the loop closure often relies on visual bag-of-words based on point features in the previous works, however, in this paper we propose a line-based method to solve the loop closure in the corridor environments. We used both the floor line and the anchored vanishing point as the loop closing feature, and a two-step loop closure algorithm was devised to detect a known place and perform the global pose correction. We propose an anchored vanishing point as a novel loop closure feature, as it includes position information and represents the vanishing points in bi-direction. In our system, the accumulated heading error is reduced using an observation of a previously registered anchored vanishing points firstly, and the observation of known floor lines allows for further pose correction. Experimental results show that our method is very efficient in a structured indoor environment as a suitable loop closure solution.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.496-500
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• 2001

There are two ways in the output voltage control method in PWM inverter. One is the double loop voltage control composed of inner current control loop and outer voltage control loop. Because it shows fast response and low steady state error, utilized in many application. The Other is single loop voltage control method composed of voltage control loop only. It's characteristics shows lower performance in case of high output impedance than double loop voltage control. But in low output impedance, it shows good control performance in all load range than double loop control. In this paper, single loop voltage control rule and gain was developed analytically, and these were verified through computer simulation and experiment.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.565-569
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• 2006

This paper reviews some loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.644-646
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• 2004

The closed loop identification(CLID) is a very useful method for on-line applications since it can identify the plant in the closed-loop system composed of the plant and the controller. There are some literatures on CLID, but they and mainly focused on SISO(Single-Input/Single-Output) problem. In this paper, a CLID method is proposed for MIMO(Multi-Input/Multi-Output) systems. The CLID method is applied to a MIMO benchmark plant, TRMS(Twin-Rotor MIMO System). To illustrate the performance of the closed-loop system identification., unit step responses in the TRMS are represented and compared with the open-loop identification via some simulation.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.353-356
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• 2005

A loop RFID tag antenna and a dipole RFID antenna with a T-matching method have been designed. The characteristic of loop and dipole with T-matching antenna structures of RFID tag antennas have been studied. The impedance of different sizes of loop and dipole antenna structures are found. This paper shows parametric research of loop RFID antenna structure and RFID dipole antenna with T-matching method to match the impedance of commercially available RFID chips.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1700-1708
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• 2006

Since the most program execution time is consumed in a loop structure, extracting parallelism from loop programs is critical for the taster program execution. In this paper, we proposed data dependency removal method for a single loop. The data dependency removal method can be applied to uniform and non-uniform data dependency distance in the single loop. Procedure calls parallelisms with only a single loop structure or procedure call most of other methods are concerned with the uniform code within the uniform data dependency distance. We also propose an algorithm, which can be applied to uniform, non-uniform, and complex data dependency distance among the multiple procedures. We compared our method with conventional methods using CRAY-T3E for the performance evaluation. The results show that the proposed algorithm is effective.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.2
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• pp.59-61
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• 2006

In our country most of transmission lines are double-circuit lines. In these lines, the combining method of increasing conductor height and installation of passive shield-loop to mitigate magnetic field near a transmission line, is a good and feasible method. The basic principle of passive shield loop is that the field from the current induced in the shield loop conductors counteracts the field from the phase conductors. This method applied to domestic transmission lines to meet the magnetic field level, 100, 30, 10 and 4 mG, respectively. In each magnetic field level, the minimum conductor height and passive loop height are presented for the implementation of the practical design.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1068-1070
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• 2000

This paper presents a method of designing the control loop for dc-to-dc converters when at characteristics of the converter's load are unknown. In the proposed method, a converter is considered as a stand-alone module that feeds a current sink load, and the control loop is designed in order to maximize the robustness of the converter's closed-loop performance. The proposed method yields a control design that provides predictable and controllable closed-loop performance for the converter loaded with an actual load.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.11-16
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• 2005

This paper proposed a new IMC-PID controller design method using the loop shaping method. By the application of the loop shaping method for IMC-PID controller which has only one design parameter and guarantees internal stability, we can not only consider such design specifications as gain margin, phases margin, and sensitivity functions but also obtain the loop gain by setting up the relationships between design specifications and design parameters. A systematic method to select design parameters of IMC-PID controller in order to meet the design specifications is suggested and its effectiveness is examined by the case study and analysis.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.17-22
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• 2007

Recent new packages such as MCP(Multi-Chip Package), QDP(Quadratic Die Package) and DDP(Dual Die Package) have stack type configuration. This kind of multi-layer package is thicker than single layer package. So there is need for the low height looping technology in wirebonder to make these packages thinner. There is stiff zone above ball in wirebonder wire which is called HAZ(Heat Affect Zone). When making low height loop (below $80\;{\mu}m$) with traditional forward loop, stiff wire in HAZ(Heat Affected Zone) above ball is bended and weakened. So the traditional forward looping method cannot be applied to low height loop. SSB(stand-off stitch) wire bonding method was applied to many packages which require very low loops. The drawback of SSB method is making frequent errors at making ball, neck damage above ball on lead and the weakness of ball bonding on lead. The alternative looping method is BNL(ball neckless) looping technology which is already applied to some package(DDP, QDP). The advantage of this method is faster in bonding process and making little errors in wire bonding compared with SSB method. This paper presents the result of BNL looping technology applied in assembly house and several issues related to low loop height consistence and BNL zone weakness.