• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.107-117
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• 1996

This paper proposes a conceptual model for distributed problem solving(DPS), where cooperation and communication among agents are based on virtual shared memory (VSM) In this model, all agents in a DPS system view all the memory in a distributed computer system as a single shared memory in which data, tasks, and results can in a distributed computer system as a single shared memory, in which data, tasks, and results can / be accessed by any of the agents. Several agents cooperatively solve a complex problem, as agents write data, intermediate results of execution, and tasks requested to other agents to VSM and other agents read or execute them. Also, in order to develop DPS systems based on the proposed conceptual model, this paper designs a DPS system development environment(DPS-VSM)using Network Linda. Thi spaper shows utility ofthe proposed model by presenting an example of simulation a VSM-based DPS system, and analyzes the model by comparing the features of DPS- VSM with some other DAI programming shells.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.4
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• pp.420-430
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• 2003

This paper presents an immersive multimodal Gumdo simulation game that allows a user to experience the whole body interaction with an intelligent cyber fencer. The proposed system consists of three modules: (i) a nondistracting multimodal interface with 3D vision and speech (ii) an intelligent cyber fencer and (iii) an immersive feedback by a big screen and sound. First, the multimodal Interface with 3D vision and speech allows a user to move around and to shout without distracting the user. Second, an intelligent cyber fencer provides the user with intelligent interactions by perception and reaction modules that are created by the analysis of real Gumdo game. Finally, an immersive audio-visual feedback by a big screen and sound effects helps a user experience an immersive interaction. The proposed system thus provides the user with an immersive Gumdo experience with the whole body movement. The suggested system can be applied to various applications such as education, exercise, art performance, etc.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.909-915
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• 2014

Terminal voltage of the Automatic Voltage Regulator(AVR) of brushless synchronous generator is generally being controlled by PID Control way in shore and ship field. However, in case of changeable large load on power system, PID control method is deficiency to respond output voltage with settling time. Hence, taking into consideration this situation, it is required new control method. In this thesis, we propose Fuzzy Logic Control(FLC) which has more optimal robust control way in order to respond varying values of terminal voltage to the brushless synchronous generator through simulation of MATLAB/SIMULINK and prove Fuzzy logic control more optimal compared with PID control.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.2
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• pp.88-93
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• 2017

Due to the requirement of the development of the precision manufacturing industry, the accuracy of machine tools has become a key issue in this field. A critical factor that affects the accuracy of machine tools is the feed system, which is generally driven by a ball screw. Basically, to improve the performance of the feed drive system, which will be thermally extended lengthwise by continuous usage, a thermal error compensation system that is highly dependent on the feedback temperature or positioning data is employed in the machine tool system. Due to the overdependence on measuring technology, the cost of the compensation system and low productivity level are inevitable problems in the machine tool industry. This paper presents a novel feed drive thermal error compensation system method that could compensate for thermal error without positioning or temperature feedback. Regarding this thermal error compensation system, the heat generation of components, principal of compensation, thermal model, mathematic model, and calculation method are discussed. As a result, the test data confirm the correctness of the developed feed drive thermal error compensation system very well.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.480-486
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• 2012

There has been an increasing interest in new industry and demand creations by the convergence and integration between IT and infrastructure and BT, NT, and CT and the convergence of IT and spread of cloud computing have changed the IT service environment. Even in the educational field, the convergence and integration of contents with various IT have rapidly emerged and learning equipments for the educational purpose have expanded to the mobile media platform from PCs so that learning without limitations to time, place and equipment has become possible. Contents necessary for the smart education are under way by research development utilizing cyber reality and simulation, and 3D technologies. The purpose of this study is to propose marine contents use and service plans for the educational purpose in order to produce various types of contents for the marine life and environment, to improve the school achievement by stimulating interest and to provide individually customized learning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.16-23
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• 2018

Chaos is one of the most significant topics in nonlinear science, and has been intensively studied since the Lorenz system was introduced. One characteristic of a chaotic system is that the signals produced by it do not synchronize with any other system. It therefore seems impossible for two chaotic systems to synchronize with each other, but if the two systems exchange information in just the right way, they can synchronize. This paper addresses the problem of synchronization in a modified Lorenz chaotic system based on active control, sliding mode control, and the Lyapunov stability theory. The considered synchronization scheme consists of identical drive and response generalized systems coupled with linear state error variables. For this, a brief overview of the modified Lorenz chaotic system is given. Then, control rules are derived for chaos synchronization via active control and slide mode control theory, with a strategy for solving the chattering problem. The asymptotic stability of the overall feedback system is established using the Lyapunov stability theory. A set of computer simulation works is presented graphically to confirm the validity of the proposed method.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1365-1371
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• 2011

The intensity and duration of sexual behavior in Bos indicus was assessed through the continuous observation of sexual receptivity. Two groups of cows were formed: only synchronized (n = 50) and other group further superovulated (n = 20). An intravaginal implant that released progesterone over 9 d was used. After removing the implant, 25 mg of $PGF_{2{\alpha}}$ was administered. In the superovulated group, the administration of 280 mg (Follicle stimulant hormone) FSH-P1 per cow with a decreasing dosage over 4 d was utilized. In both groups, behavioral observations began at the moment of implant removal. Sexual behavior was analyzed using a Kruskal-Wallis test to compare the mean of hours in estrus, effective mountings and number of mounts/hour during estrus. A nonparametric survival analysis was performed using the time in two ways: i) when an event happened it was placed in a 24 h timeframe and, ii) the time of observation in continuous form (96 h) assessing the difference between curves by the log rank test Chi-square. The only significant difference was the number of mounts/h during receptivity (p<0.05). In the superovulated group three periods of sexual activity during the day were identified, with these events being of greater frequency and duration than the synchronized group (p = 0.02); besides, the superovulated group began estrus before the synchronized group (p = 0.0035) when using the total period. In a simulation study, when the number of observations went from two (06:00-18:00) to three periods (06:00, 12:00 and 18:00) cows detected accurately (<6 h after the onset) increased more than 20%. The results show that superovulated cows presented greater intensity and duration of sexual activity in contrast with only synchronized animals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3644-3649
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• 2013

Automotive seat recliner has the function to control the angle at the back of chair and has the relation close to the safety of seat. Therefore each of parts constituting the recliner is important and the recliner housing to protect these parts from various dynamic loads is also important. In this study, the recliner housing with t=3mm which is made of high tension steel plate(SPFC 980) is applied to actual automotive seat. The deformation is investigated through the durability tester. Deformation and equivalent stress are also analyzed by simulation analysis under the same condition with experiment. After recliners with thicknesses of 1mm and 2mm are modeled by bases of experimental and analysis values, deformation and equivalent stress are investigated through structural analysis.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.63-69
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• 2006

Recently there are increasing needs for Internet and various kinds of contents. These traffics for various contents need more amount of data to provide high-quality information and require various QoS depending on the characteristics of contents. However, current Internet service supports BE (Best Effort) service only, therefore IntServ (Integrated Service) scheme and DiffServ (Differentiated Service) scheme are represented to support QoS in IP layer. Moreover, while wireless Internet is getting popular, MAC(Medium Access Control) is also becoming important. This is due to the fact that wireless access, resource allocation and packet scheduling, which are done in another layers before, are performed in MAC layer in many new wireless systems. This paper describes new scheme that provides QoS taking into account the traffic characteristics over Mobile IPv6 network based on IEEE 802.11e EDCF and evaluates the performance through computer simulation.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.4
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• pp.216-222
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• 2006

Vector field has been commonly used to visualize the data set which is invisible or is hard to explain. For instance, it could be used to visualize scientific data such as the direction and amount of wind and water field, transfer of heat through thermally conductive materials, and electromagnetic field. In this paper, we present a technique to enable intuitive recognition of the data though haptic feedback along with visual feedback. To add tactile information to graphical vector field, we model a haptic vector field and then apply it to the haptic map to guide a user to destination and haptic simulation of water field on 2D images whish can be used ill everyday life. These systems allow one to recognize vector information intuitively through haptic interface. We expect that the haptic rendering technique of vector field can be applied to various applications such as education, training, and entertainment.