• Korean Journal of Labor Studies
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• v.24 no.2
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• pp.409-441
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• 2018

This study is a case study about the Valero Energy Corporation, the largest American independent refinery company, examining the characteristics of human resource management as a union avoidance strategy. The main research questions here are whether union substitution strategy differs clearly from union suppression strategy in the context of Valero Energy. Since the establishment in 1980, the Valero had maintained non-union tradition. The typical examples of human resource management in the non-unionized American companies are easily found in the Valero, such as strong CEO leadership, manpower policy emphasizing corporate culture and teamwork, direct communication between company and individual employees, no lay-off policy and no outsourcing policy of HRM, salary level around average of industry and best level of fringe benefits in the industry, non-union tradition and well-functioned alternative dispute resolution system and so on. Until now, based on tremendous growth and profitability, the company have applied union substitution method adopted by good companies as concrete method of union avoidance strategy instead of union suppression method that marginal enterprise prefers.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.363-364
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• 2020

본 논문은 최근 주목 받고 있는 데이터 기반 인공지능 알고리즘을 사용하는 배터리 충전 상태 추정 기법에 대하여 조사 분석한다. 기존의 배터리 모델링 기법의 단점을 회피할 수 있는 데이터 기반 인공지능 알고리즘의 구조적 특징을 확인하고, 배터리 충전 상태 추정에 데이터 기반 인공지능 알고리즘을 적용 했을 때, 충전 상태 추정 정확도에 영향을 끼치는 요소인 데이터 구성에 대한 분석을 실시하여, 데이터 구성 시 필수적으로 고려해야하는 설계조건을 조사 분석한다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.377-388
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• 2020

In this paper, the autonomous mobile robot whit only LRF sensors proposes an algorithm for avoiding moving obstacles in an environment where a global map containing fixed obstacles. First of all, in oder to avoid moving obstacles, moving obstacles are extracted using LRF distance sensor data and a global map. An ellipse-shaped safety radius is created using the sum of relative vector components between the extracted moving obstacles and of the autonomuos mobile robot. Considering the created safety radius, the autonomous mobile robot can avoid moving obstacles and reach the destination. To verify the proposed algorithm, use quantitative analysis methods to compare and analyze with existing algorithms. The analysis method compares the length and run time of the proposed algorithm with the length of the path of the existing algorithm based on the absence of a moving obstacle. The proposed algorithm can be avoided by taking into account the relative speed and direction of the moving obstacle, so both the route and the driving time show higher performance than the existing algorithm.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.103-111
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• 2021

The purpose of this study is to study a method for preventing collisions of multiple drones in controlled airspace. As a result of the study, it was proved that it is appropriate as a method to control drone collisions after setting accurate information on the ROI (Region of Interest) area estimated based on the expected drone path and time in the control system as a method to avoid drone collision. As a result of the empirical analysis, the diameter of the flight path of the operating drone should be selected to reduce the risk of collision, and the change in the departure time and operating speed of the operating drone did not act as an influencing factor in the collision. In addition, it has been demonstrated that providing flight priority is one of the appropriate methods as a countermeasure to avoid collisions. For collision avoidance methods, not only drone sensor-based collision avoidance, but also collision avoidance can be doubled by monitoring and predicting collisions in the control system and performing real-time control. This study is meaningful in that it provided an idea for a method for preventing collisions of multiple drones in controlled airspace and conducted practical tests. This helps to solve the problem of collisions that occur when multiple drones of different types are operating based on the control system. This study will contribute to the development of related industries by preventing accidents caused by drone collisions and providing a safe drone operation environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.636-637
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• 2018

The electronic shelf label(ESL) system based on wireless communication can reduce waste of disposable paper, reduce labor force and update real time information. However, the environment in which a large number of ESL modules are installed is exposed to interference from radio frequency(RF) communications in the Industry-Science-Medical(ISM) band. In this paper, we propose an ESL system based on visible light communication to avoid congestion of ESL system using ISM band. In the proposed system, the goods information and ID transmitted from the administrator server are transmitted in the ESL Tag, and the ESL Tag identifies the ID and displays the product information. Experiments show that ESL system using visible light communication is possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.300-302
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• 2022

In this paper, We propose a mobility model-based resource collision avoidance technique that can share radio resources without resource collision between UAV in a FANET environment. The proposed technique tries to reduce the occurrence of resource collisions by estimating UAV mobility based on information obtained from GPS devices installed in UAV. Through simulations, The performance was compared with the contention-based protocol, and it was confirmed that the proposed algorithm can reduce resource collisions.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.599-602
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• 2007

Generally, the mobile robot navigation with obstacle avoidance is one of the key issues to be looked into for successful applications of autonomous mobile robots. In this paper, the Univector field based method is proposed for mobile robot to accomplish the obstacle avoidance and the robot orientation at the target position. Univector field method guarantees the desired posture of the robot at the target position. But it is not effective Univector to avoid obstacles. To solve this problem, modified univector field is used. With this proposed method, robot navigation task becomes easier and effectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1104-1111
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• 2009

In the low altitude, mission of the aircraft is restricted by a variety of threats such as anti-air missiles and terrain obstacles. Especially, aircraft have always a risk of ground collision near terrain. In this study, to effectively solve this problem, we developed the flight path generation algorithm that is considered the terrain avoidance. In this flight path generation algorithm, waypoints that should be passed by the UAV are selected first. The waypoints are located in the middle of the terrain obstacles. Then, physically meaningful waypoints sets are classified by Dijkstra algorithm. The optimal waypoint guidance law based on the optimal control theory is applied to produce trajectory candidates. And finally the minimum control energy trajectory is determined.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2937-2943
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• 2013

This paper introduces a real-time flocking simulation framework through radial basis function(RBF). The proposed framework first divides the entire environment into a grid structure and then assign a vector per each cell. These vectors are automatically calculated by using RBF function, which is parameterized from user-input control lines. Once the construction of vector field is done, then, flocks determine their path by following the vector field flow. The collision with static obstacles are modeled as a repulsive vector field, which is ultimately over-layed on the existing vector field and the inter-individual collision is also handled through fast lattice-bin method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2328-2333
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• 2010

A direct boundary element method(DBEM) is widely applied for various acoustic wave problems. But this method has numerically non-unique solutions around the eigenfrequencies of the interior Dirichlet problem for the region enveloped with the acoustic boundary. A CHIEF method had been generally adopted to resolve the non-uniqueness problem and a new technique called ICA-Ring method has been suggested recently. In this paper, the characteristics of two techniques for avoiding the non-uniqueness of DBEM are examined and numerical codes embodying both techniques are developed. Numerical calculations are also carried out for an uniformly pulsating sphere, of which the results are investigated by including the comparisons with theoretical solutions.