• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.896-899
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• 1996

A new algorithm for planning a collision free path is developed based on linear parametric curve. A collision-free path is viewed as a connected space curve in which the path consists of two straight curve connecting start to target point. A single intermediate connection point is considered in this paper and is used to manipulate the shape of path by organizing the control point in polar coordinate (.theta.,.rho.). The algorithm checks interference with obstacles, defined as GM (Geometry Mapping), and maps obstacles in Euclidean Space into images in CPS (Connection Point Space). The GM for all obstacles produces overlapping images of obstacle in CPS. The clear area of CPS that is not occupied by obstacle images represents collision-free paths in Euclidean Space. Any points from the clear area of CPS is a candidate for a collision-free path. A simulation of GM for number of cases are carried out and results are presented including mapped images of GM and performances of algorithm.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.135-137
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• 2004

In this paper, a new method which is based on mathematics is proposed for the obstacle-avoidance and path-planning (OAPP) of robotics in unknown environment. The robot just knows the start point and the goal point. The robot is represented by a circle(not a point) whose radius is one. After being sensed, the obstacles are represented by some mathematic functions and when avoiding the obstacles, the robot path will be generated autonomously. Along this path, the robot can get the goal point at last. The simulation results show that the proposed method works very well.

• Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.132-139
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• 2016

In this paper, a minimum time path planning strategy is proposed for multi points manufacturing problems in drilling/spot welding tasks. By optimizing the travelling schedule of the set points and the detailed transfer path between points, the minimum time manufacturing task is realized under fully utilizing the dynamic performance of robotic manipulator. According to the start-stop movement in drilling/spot welding task, the path planning problem can be converted into a traveling salesman problem (TSP) and a series of point to point minimum time transfer path planning problems. Cubic Hermite interpolation polynomial is used to parameterize the transfer path and then the path parameters are optimized to obtain minimum point to point transfer time. A new TSP with minimum time index is constructed by using point-point transfer time as the TSP parameter. The classical genetic algorithm (GA) is applied to obtain the optimal travelling schedule. Several minimum time drilling tasks of a 3-DOF robotic manipulator are used as examples to demonstrate the effectiveness of the proposed approach.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1341-1346
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• 2015

Nowadays, many small businesses have experienced the failure of business or hardship. In this point, specific and integrated information for startup business should be required to decrease the rate of failure and to increase the rate of success. This study is to suggest the integration of various data which various public institutions have separately. For this purpose, it is to classify the data types in constructing big-data for start-up business and to suggest a way of data integration, analysis method, and web or services of information system for supporting startup businesses.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.1
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• pp.38-43
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• 2011

This paper presents the improvement of start-up characteristic of sensorless controlled IPMSM(Interior Permanent Magnet Synchronous Motor) with SMO(Sliding Mode Observer). It is difficult to utilize the rotor position information at starting point for the back EMF estimation based sensorless control. For this reason, open loop control is normally used during start-up period. However, changing from open loop to closed loop control might bring a problem on the transient characteristics for difference load conditions. To solve this problem, we add another rotor angle controller. Simulation results and experimental results are presented to verify proposed method.

• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.5-19
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• 2018

The characteristics of the skin shear stress distribution for the fixed length of the ground anchor are extremely nonlinear and the engineering mechanisms are complex relatively. So it is difficult to design the anchors simulating the actual behavior by considering various soil conditions and nonlinear behavior. Due to these limits, constant skin shear stress distributions for the whole fixed length of the ground anchor are usually assumed in the design for the sake of convenience. In this study, to assess the pull-out behavior of the tension-type ground anchors, the in-situ pull-out tests in weathered-soil conditions were carried out. Based on the test results, the skin shear behaviors for the fixed length of tension-type ground anchors were established and the multi-linear slip shear model predicting this behavior and an analytical technique applying this model were proposed. From the similarity between the results of the in-situ pull-out tests and those of the analytical technique, the applicability and availability of the multi-linear slip shear model and the proposed analytical technique were verified. The maximum shear stress was developed at the start point of the fixed length acting with the smaller load than the maximum pull-out load but the minimum shear stress was developed at the start point of the fixed length and the maximum shear stress was developed at the point apart from the start point of the fixed length after the maximum pull-out load.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1996.11a
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• pp.49-52
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• 1996

This paper reports the development of an electronic starter for fluorescent lamps, which is so smartly designed that can be used directly in existing installations. The key point of the design lies in the protection of lamp filaments by sufficient preheating and at the same time in the control of time constant for start-up circuit. The starter is consisted of three system parts: a rectifier pact, a switching part. and a gate control part. The characteristics of the developed electronic starter is compared with those of a conventional glow starter. As a result, blackening of lamps is almost reduced due to the stable and idealized start-up characteristics. And, furthermore, it is shown that its slaving time is shortened at about half the level of the conventional one and the starting power is also reduced.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.131.4-131
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• 2001

A lot of path planning algorithms have been developed to find the collision-free path with minimum cost. But most of them require complicated computations. In this paper, a thinning method, which is one of the image processing schemes, was adopted to simplify the path planning procedure. In addition, critical points are used to find the shortest-distance path among all possible paths from the start to the goal point. Since the critical points contain the information on the neighboring paths, a new path can be quickly obtained on the map even when the start and goal points change. To investigate the validity of the proposed algorithm, various simulations have been performed for the environment where the obstacles with arbitrary shapes exist. It is shown that the optimal paths can be found with relative easiness.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.711-724
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• 2017

The purpose of this research is to go beyond the policy support of the traditional sixth industry and to build a business model of the farmers' business by establishing the business model of the establishment of the sixth industry utilizing agricultural products of individual farmers. First, we defined the business model of the 6th agricultural industry, and secondly set up two models via FGI based on the 9 block model of BMC (Business Model Canvas), and applied feasibility, cost appropriate, differentiation point Through the establishment of hard-working business, sales consolidation, consumer-centric model set. Third, using the Delphi method in each area of 9 Block, the final 21 components were set. Through this BMC model, it was shown that discrimination and accessibility are important factors in the 6th agricultural field foundation business model.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.228-233
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• 1999

In this paper we develop an electronic starter circuit that is suitable for Neon sign operation of switch-start fluorescent lamps. The developed starter enable single pulse ignition of fluorescent lamp at the peak point of preheating current, irrespective of the position of the Tum-On signal. This is possible due to the sequential operation of two transistors different in their operation characteristics and a diode operation characteristic. The switching endurance test using this starter has been carried for more than 3000 hours for a single switch-start on a severe blinking condition of preheating of 0.1s and of successive lighting interval of 0.1s.