• Journal of Institute of Control, Robotics and Systems
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• v.19 no.12
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• pp.1132-1137
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• 2013

In swarm robot systems, it is vital to maintain network connectivity to ensure cooperative behavior between robots. This paper deals with the behavior control algorithm of the swarm robots for maintaining network connectivity. To do this, we divide swarm robots into search-robots, base-robots, and relay-robots. Using these robots, we propose behavior control algorithm to maintain network connectivity. The behavior control algorithms to maintain network connectivity are proposed for the local path planning using virtual force and global path planning using the Delaunay triangulation, respectively. Finally, we demonstrate the effectiveness and applicability of the proposed method through some simulations.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.4
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• pp.314-320
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• 2006

Navigation in environments that are densely cluttered with obstacles is still a challenge for Autonomous Ground Vehicles (AGVs), especially when the configuration of obstacles is not known a priori. Reactive local navigation schemes that tightly couple the robot actions to the sensor information have proved to be effective in these environments, and because of the environmental uncertainties, STSF(Space and Time Sensor Fusion)-based fuzzy behavior systems have been proposed. Realization of autonomous behavior in mobile robots, using STSF control based on spatial data fusion, requires formulation of rules which are collectively responsible for necessary levels of intelligence. This collection of rules can be conveniently decomposed and efficiently implemented as a hierarchy of fuzzy-behaviors. This paper describes how this can be done using a behavior-based architecture. The approach is motivated by ethological models which suggest hierarchical organizations of behavior. Experimental results show that the proposed method can smoothly and effectively guide a robot through cluttered environments such as dense forests.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.3
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• pp.16-22
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• 2006

The friction and wear of tire determined by frictional behavior of tire tread that translate driving force, cornering force and braking force between automobile and road as a result of frictional behavior of each tread block. The tire tread block is representative case of rubber block doing frictional behavior. In this paper, frictional behavior of rubber block under compressive force and shear force was analytically obtained by using slip starting position parameter instead of friction coefficient which is uncertain to express exact value between rubber and other surfaces yet. And local coefficients of friction were calculated as a function of compressive force, shear force, shear modulus of rubber, shape factor and slip starting position.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.29-37
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• 2015

Nowadays, the user-centric application based web 2.0 has replaced the web 1.0. The users gain and provide information by interactive network applications. As a result, traditional approaches that only extract and analyze users' local document operating behavior and network browsing behavior to build the users' preference profile cannot fully reflect their interests. Therefore this paper proposed a preference analysis and indicating approach based on the users' communication information from MicroBlog, such as reading, forwarding and @ behavior, and using the improved PersonalRank method to analyze the importance of a user to other users in the network and based on the users' communication behavior to update the weight of the items in the user preference. Simulation result shows that our proposed method outperforms the ontology model, TREC model, and the category model in terms of 11SPR value.

• Management & Information Systems Review
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• v.35 no.2
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• pp.137-165
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• 2016

Community enterprise is a type of business that simultaneously pursues public interest and profitability to vitalize the local society and economy and also an alternative endeavor to restore community by local residents using local resources. In rapid changes of business environment and social dynamics of these days, one of the alternatives to provide solutions for problems in persons and organizations is workplace spirituality. Workplace spirituality is not only beneficial to satisfaction, commitment, devotion, and organizational citizenship behavior, but also positively influential to outcome of an organization. Expanding the scope and subjects found in most previous studies on workplace spirituality of general companies, this study tries to contribute to development of community enterprises through empirical analysis of the effect of community enterprise. In result, workplace spirituality showed positively significant influence on job satisfaction, organizational citizenship behavior equally in both of community enterprises and general companies. Job satisfaction presented positively significant effect on organizational citizenship behavior. And job satisfaction mediated the relationship between workplace spirituality and organizational citizenship behavior. In addition, workplace spirituality of community enterprises showed difference from general companies showed greater coefficient and influence. Although workplace spirituality is important for general companies that pursue profit, it is shown that greater significance was found in community enterprises. Workplace spirituality, which is equivalent to A sense of calling, sense of inner life, sense of empathy, sense of community, and sense of transcendence through community enterprise, needs to be promoted and settled in community enterprises.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.63-74
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• 2020

This study investigates the behavior of foreign investors in the Stock Exchange of Thailand (SET) in the time of coronavirus disease 2019 (COVID-19) as to whether trading is abnormal, what strategy is followed, whether herd behavior is present, and whether the actions destabilize the market. Foreign investors' trading behavior is measured by net buying volume divided by market capitalization, whereas the stock market behavior is measured by logged return on the SET index portfolio. The data are daily from Tuesday, August 28, 2018, to Monday, May 18, 2020. The study extends the conditional-regression model in an event-study framework and extracts the unobserved abnormal trading behavior using the Kalman filtering technique. It then applies vector autoregressions and impulse responses to test for the investors' chosen strategy, herd behavior, and market destabilization. The results show that foreign investors' abnormal trading volume is negative and significant. An analysis of the abnormal trading volume with stock returns reveals that foreign investors are not positive-feedback investors, but rather, they self-herd. Although foreign investors' abnormal trading does not destabilize the market, it induces stock-return volatility of a similar size to normal trade. The methodology is new; the findings are useful for researchers, local authorities, and investors.

• Journal of Korean Society of Steel Construction
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• v.15 no.4 s.65
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• pp.423-433
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• 2003

Many study have been performed to describe the elastic and inelastic behavior of H-shaped beams with web openings that generally concentrated on the monotonic loading condition and concentric web opening. The findings of the studies led Darwin to propose formulas for the design of beams with web openings considering local buckling. While the formulas are simple and useful in real situation, more studies arc needed on their cyclic loading condition. In this experimental study, 12 H-shaped beams with web openings under cyclic loading condition were investigated. The dimension criteria based on the formulas proposed by Darwin were examined. The suitability of existing design formulas and the effects of plastic hinges on beams with web openings and of local buckling around web openings on the beam strength under cyclic loading were also studied. This was done by observing their behavior with various dimensional openings, eccentric per cent, and stiffeners.

• Steel and Composite Structures
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• v.48 no.1
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• pp.27-41
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• 2023

Under the long-term effect of corrosive environment, many cold-formed steel (CFS) structures have serious corrosion problems. Corrosion leads to the change of surface morphology and the loss of section thickness, which results in the change of instability mode and failure mechanism of CFS structure. This paper mainly investigates the elastic local buckling behavior of corroded CFS columns. The surface morphology scanning test was carried out for eight CFS columns accelerated corrosion by the outdoor periodic spray test. The thin shell finite element (FE) eigen-buckling analysis was also carried out to reveal the influence of corrosion surface characteristics, corrosion depth, corrosion location and corrosion area on the elastic local buckling behaviour of the plates with four simply supported edges. The accuracy of the proposed formulas for calculating the elastic local buckling stress of the corroded plates and columns was assessed through extensive parameter studies. The results indicated that for the plates considering corrosion surface characteristics, the maximum deformation area of local buckling was located at the plates with the minimum average section area. For the plates with localized corrosion, the main buckling shape of the plates changed from one half-wave to two half-wave with the increase in corrosion area length. The elastic local buckling stress decreased gradually with the increase in corrosion area width and length. In addition, the elastic local buckling stress decreased slowly when corrosion area thickness was relatively large, and then tends to accelerate with the reduction in corrosion area thickness. The distance from the corrosion area to the transverse and longitudinal centerline of the plate had little effect on the elastic local buckling stress. Finally, the calculation formula of the elastic local buckling stress of the corroded plates and CFS columns was proposed.

• Culinary science and hospitality research
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• v.17 no.3
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• pp.20-32
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• 2011

The purpose of this study is to analyze customers' behavior in using word-of-mouth(WOM) information about Korean local food restaurants. The questionnaire developed for this study was distributed to 500 customers living in Jeonbuk area and a total of 455 copies (91.0%) were used for analysis. The statistical analysis was conducted using SPSS Win(12.0). The results were summarized as follows. The recommendation of people experienced'($M=3.57{\pm}1.24$) and 'word-of-mouth through people around'($M=3.52{\pm}1.20$) were major word-of-mouth information sources of Korean local foods; 'taste of food'($M=4.16{\pm}1.15$) and 'service quality'($M=3.79{\pm}1.11$) were important attributes in word-of-mouth information. In addition, to the question about the reasons for recommending the restaurant to the people around, the most people replied that 'flavor, nutrition and quality of local foods can be kept only in the specific location' ($3.53{\pm}1.08$), followed by 'to keep the memory of the visit to the areas in mind through local foods'($3.51{\pm}1.03$). These results showed that people usually recommend a restaurant based on the quality of the food itself or local characteristics. As a result, it is deemed that word-of-mouth effect is an important factor for the spread of Korean local foods.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.164-169
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• 1998

Complex "lifelike" behaviors are composed of local interactions of individuals under fundamental rules of artificial life. In this paper, fundamental rules for cooperative group behaviors, "flocking" and "arrangement", of multiple autonomous mobile robots are represented by a small number of fuzzy rules. Fuzzy rules in Sugeno type and their related paramenters are automatically generated from clustering input-output data obtained from the algorithms the group behaviors. Simulations demonstrate the fuzzy rules successfully realize group intelligence of mobile robots.