• Journal of the Korea Society of Computer and Information
• /
• v.23 no.3
• /
• pp.25-31
• /
• 2018

In this paper, we consider the game theoretic approach to investigate the transmit power optimization problem where D2D users share the uplink of the cellular system. Especially, we formulate the transmit power optimization problem as a non cooperative power control game. In the user wide sense, each user may try to select its transmit power level so as to maximize its utility in a selfish way. In the system wide, the transmit power levels of all users eventually converge to the unique point, called Nash Equilibrium. We first formulate the transmit power optimization problem as a non cooperative power control game. Next, we examine the existence of Nash Equilibrium. Finally, we present the numerical example that shows the convergence to the unique transmit power level.

• Proceedings of the KIEE Conference
• /
• 2001.11c
• /
• pp.95-98
• /
• 2001

A hierarchical structure for the cooperative control of multiple mobile robots using coordinates of objects obtained from vision system is proposed. The order-level perceives environments represented by workspace sets. The algorithm selects an object to be moved using an object discrimination part and determines the robot actions. The action-level generates a trajectory of each wheel velocity of robot. The simulation results show the effectiveness of the proposed algorithm.

• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2411-2413
• /
• 2004

In this paer, we propose a method to apply a decentralized control algorithm for passive velocity field control using virtual flywheel system to cooperative mobile robots. The considered system convey a common rigid object in a horizontal plain. The effectiveness of proposed control algorithm is examined by numerical simulation for cooperative tasks.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.1 no.2
• /
• pp.17-37
• /
• 1995

Since the inception of the Paris Memorandum of Understanding 1982, Port State Control has been recognised as one of the most effective measures available to eradicate substandard shipping from the oceans of the world. This paper explains the basis, genesis and developmt of cooperative arrangements in Port State Control, and aims to suggest that Korea government and shipwoners should be ready to response to the adoption of cooperative arrangement in Port State Control of Asia-Pacific region.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.12
• /
• pp.2078-2090
• /
• 2001

This paper deals with a precise position synchronous control by a cooperative control method of two axes rotating systems. First, the system's dynamics including motor drives described by a motor circuit equation and Newton's kinetic formulation about rotating system. Next, based on conventional PID(Proportional, Integral, Derivative) control law, current and speed controller are designed very simply to follow up reference speed correctly under some disturbances. Also, position synchronous controller designed to minimize position errors according to integration of speed errors between two motors. Then, the proposed control enables the distributed drives by a software control algorithm to behave in a way as if they are mechanically hard coupled in axes. Further, the stabilities and robustness or the proposed system are investigated. Finally, the proposed system presented here is shown to be more precise position synchronous motion than conventional systems through some simulations and experiments.

• The Journal of Fisheries Business Administration
• /
• v.22 no.2
• /
• pp.101-148
• /
• 1991

The fisheries cooperative (FC) performs the economic and nonprofitable activity to get the fundamental objective of enhancing cooperative members' economic and social position. The internal control system fitted for a local FC should be required for not only solving the resulting problem from the complexity of FC environment nowaday but also delegating authorities and performance from FC Federation to a local FC by implementing the local autonomy. The methodology of this study is to empirically test and to analyze the condition of FC internal control system (FCICS) by the questionnaire survey. The actual condition of FCICS in Korea is analyzed by the questionnaire and the detailed contents are as follows : (1) sending 208 questionnaire consisting of 162 questions, and receiving 92 replies from 39 manufactures (business firms) and 15 banks in Gyungnam and Pusan area and 25 FC and 13 agricultural cooperative (AC) in Korea, (2) the analyzed results of FC and AC are treated simultaneously. In the fundamentals of above analyzed results, the evaluation model of FCICS is tried to construct from the relationship between the financial condition of FC and the internal control elements through the stepwise regression method. (1) By the stepwise regression method, the number of FC officials $(X_1)$, the experimental number of regular auditing $(X_7)$, and auditing duty years $(X_8)$ are finally accepted as independent variables, (2) and the final model becomes $Y=-1.53526+0.34455X_1+0.24513X_7+0.16585X_8$/ and this model explains to the extent of 47.826%. From the above study, following proposals are to be suggested: (1) The function and problem of internal control in FCICS is able to be improved by enforcing the function of FCICS and enriching the management's recognition of FCICS (2) The cooperative president can bring up good FC by the rational operation of FCICS according to the size and the performance pattern of FC, adding up to enhance members' economic and social position.

• Journal of Korean Public Health Nursing
• /
• v.27 no.3
• /
• pp.513-526
• /
• 2013

Purpose: The purpose of this study was to determine the effects of the Traditional Play-centered Obesity Control Cooperative Learning Program based on the cooperative learning theory on obesity rate, physical fitness, self-esteem, and body image specifically in obese elementary school children. Methods: The research design for this study was based on a non- equivalent control group pretest-posttest design. The study was conducted from September, 5 to November 30, 2012. The subjects included 74 obese children ($Exp.=25^{(a)}$, $Com.=24^{(b)}$, $Cont.=25^{(c)}$) with an obesity rate above 20% at an elementary school in G City. Data analysis was performed using SPSS/WIN 18.0, using Chi-square test, one-way ANOVA, and Scheffe test. Results: The obesity rate (F=4.033, p<.022) in the experimental group was significantly lower than that in the group (Com, Cont), in which the Traditional Play-Centered Obesity Control Cooperative Learning Program was not implemented. Self-esteem (F=4.310, p<.017) also caused significant differences. However, physical fitness (Muscular endurance F=1.545, p=.220; Flexibility F=.671, p=.514; Agility F=1.594, p=.210; Speed F=5.386, p<.007, scheffe (a,b

• Journal of Korea Multimedia Society
• /
• v.17 no.6
• /
• pp.687-696
• /
• 2014

An integrated ship area network has functionality of remote control and autonomous management of various sensors and instruments embedded or boarded in a ship. For such environment, an wireless bridge is essential to transmit control and/or managing information to sensors or instruments from a central integrated ship area network station. In this paper, one of reliable schemes of WiMedia based wireless bridge using relay cooperative transmission using WiMedia distributed MAC protocol is proposed to increase a communication reliability between cluster headers, irrespective of channel variation. Simulation results show that the proposed wireless bridge using relay cooperative transmission scheme increases communication reliability.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.3
• /
• pp.460-469
• /
• 2012

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC) protocol based on UWB for high speed wireless home networks and WPANs. In this paper, we propose a novel cooperative communication protocol adaptive to current UWB link transmission rate. The proposed cooperative communication protocol has compatibility with current WiMedia D-MAC and Wireless USB standard and is executed at each device according to a Relay Node Selection (RNS) criterion.

• International Journal of Control, Automation, and Systems
• /
• v.3 no.1
• /
• pp.1-14
• /
• 2005

This paper presents an obstacle detection algorithm based on the consecutive and the cooperative range sensor scanning schemes. For a known environment, a mobile robot scans the surroundings using a range sensor that can rotate 3600°. The environment is rebuilt using nodes of two adjacent walls. The robot configuration is then estimated and an obstacle is detected by comparing characteristic points of the sensor readings. In order to extract edges from noisy and inaccurate sensor readings, a filtering algorithm is developed. For multiple robot localization, a cooperative scanning method with sensor range limit is developed. Both are verified with simulation and experiments.