• Steel and Composite Structures
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• v.49 no.4
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• pp.381-392
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• 2023

This study experimentally investigates the flexural behavior of steel-UHPC composite slabs composed of an innovative negative Poisson's ratio (NPR) steel plate and Ultra High Performance Concrete (UHPC) slab connected via demountable high-strength bolt shear connectors. Eight demountable composite slab specimens were fabricated and tested under traditional four-point bending method. The effects of loading histories (positive and negative bending moment), types of steel plate (NPR steel plate and Q355 steel plate) and spacings of high-strength bolts (150 mm, 200 mm and 250 mm) on the flexural behavior of demountable composite slab, including failure mode, load-deflection curve, interface relative slip, crack width and sectional strain distribution, were evaluated. The results revealed that under positive bending moment, the failure mode of composite slabs employing NPR steel plate was distinct from that with Q355 steel plate, which exhibited that part of high-strength bolts was cut off, part of pre-embedded padded extension nuts was pulled out, and UHPC collapsed due to instantaneous instability and etc. Besides, under the same spacing of high-strength bolts, NPR steel plate availably delayed and restrained the relative slip between steel plate and UHPC plate, thus significantly enhanced the cooperative deformation capacity, flexural stiffness and load capacity for composite slabs further. While under negative bending moment, NPR steel plate effectively improved the flexural capacity and deformation characteristics of composite slabs, but it has no obvious effect on the initial flexural stiffness of composite slabs. Meanwhile, the excellent crack-width control ability for UHPC endowed composite members with better durability. Furthermore, according to the sectional strain distribution analysis, due to the negative Poisson's ratio effect and high yield strength of NPR steel plate, the tensile strain between NPR steel plate and UHPC layer held strain compatibility during the whole loading process, and the magnitude of upward movement for sectional plastic neutral axis could be ignored with the increase of positive bending moment.

• Journal of the Korean Home Economics Association
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• v.19 no.4
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• pp.85-96
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• 1981

The author aimed at clarifying the background variables that influence on the interpersonal behavior of youth, and getting the data for comprehensive guidance programs of youth in high schools and industries. In this study the author samples academic high school boys and girls, attached high schools boys and girls to industries and laboring youths. the Scale of interpersonal behavior was administered to the youths sampled as above and the data were analysed accounting to groups, sex, and religious. The results of the study are as follows. 1. The most important factor influenced the interpersonal behavior of youth was identified as social environment. That is, the youths in industries or students attached high school to industries showed more prominent characteristics in interpersonal behavior patterns. Then industrial environment effects more on the youth's behavior than school environment. 2. Sex differences were identified is in interpersonal behavior of youths. Boys are more managerial and autocretice, more cooperative, more docile, more self-efacing, more aggressive and more aggressive and more resistant than girls. But in christian group there found no sex differences is interpersonal behavior. 3. Religion was thought to be one of the most important influencing factor to the interpersonal behavior .But in this study there found no realistic effects, of religion on the interpersonal behavior as much as though of. 4. But according to the denominations, christianity was found to influences more on the interpersonal behavior of youths than Buddhism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.11
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• pp.3026-3045
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• 2012

In this paper, diversity-multiplexing tradeoff (DMT) of three-user wireless multiple-antenna cooperative systems is investigated in general fading channels when half-duplex and decode-and-forward relay is employed. Three protocols, i.e., adaptive protocol, receive diversity protocol, and dual-hop relaying protocol, are considered. The general fading channels may include transmit and/or receive correlation and nonzero channel means, and are extensions of independent and identically distributed Rayleigh or Rician fading channels. Firstly, simple DMT expressions are derived for general fading channels with zero channel means and no correlation when users employ arbitrary number of antennas. Explicit DMT expressions are also obtained when all users employ the same number of antennas and the channels between any two users are of the same fading statistics. Finally, the impact of nonzero channel means and/or correlation on DMT is evaluated. It is revealed theoretically that the DMTs depend on the number of antennas at each user, channel means (except for Rayleigh and Rician fading statistics), transmit and/or receive correlation, and the polynomial behavior near zero of the channel gain probability density function. Examples are also provided to illustrate the analysis and results.

• Journal of Korean Elementary Science Education
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• v.24 no.5
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• pp.595-601
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• 2005

In this study, the scientifically gifted students and the general students were compared in terms of the following components in cooperative teaming: whom they interacted with, to/from whom they gave/received help and why, and what kinds of the verbal interaction patterns they engaged in. The subjects were 4th graders. The data were collected through the investigation of the students' perception and videotaping of the small group interactions of each group. The results showed that the gifted students interacted with most students in their groups. They complemented each others' opinions and their discussion was enriched through their interactions. On the other hand, the interactions of the general students occurred mostly around a leader, and more teamed students explained the content to the less teamed students. Predominantly, the gifted students' most verbal behaviors were related with the teaming contents. Most frequent verbal behavior were a giving specific information and an explanation of their opinions. The general students, however, gave simple and short information, and more often they showed the management behaviors, such as encouraging participation and suggesting their directions.

• ETRI Journal
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• v.37 no.5
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• pp.1032-1043
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• 2015

ETRI's Co-Pilot project is aimed at the development of an automated vehicle that cooperates with a driver and interacts with other vehicles on the road while obeying traffic rules without collisions. This paper presents a core block within the Co-Pilot system; the block is named "Co-Pilot agent" and consists of several main modules, such as road map generation, decision-making, and trajectory generation. The road map generation builds road map data to provide enhanced and detailed map data. The decision-making, designed to serve situation assessment and behavior planning, evaluates a collision risk of traffic situations and determines maneuvers to follow a global path as well as to avoid collisions. The trajectory generation generates a trajectory to achieve the given maneuver by the decision-making module. The system is implemented in an open-source robot operating system to provide a reusable, hardware-independent software platform; it is then tested on a closed road with other vehicles in several scenarios similar to real road environments to verify that it works properly for cooperative driving with a driver and automated driving.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.170-175
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• 1998

Transporting a large table using multiple robotic agents requires at least two group behaviors of homing and herding which are to bo coordinated in a proper sequence. Existing GP methods for multi-agent learning are not practical enough to find an optimal solution in this domain. To evolve this kind of complex cooperative behavior we use a novel method called fitness switching. This method maintains a pool of basis fitness functions each of which corresponds to a primitive group behavior. The basis functions are then progressively combined into more complex fitness functions to co-evolve more complex behavior. The performance of the presented method is compared with that of two conventional methods. Experimental results show that coevolutionary fitness switching provides an effective mechanism for evolving complex emergent behavior which may not be solved by simple genetic programming.

• Journal of The Korean Association For Science Education
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• v.34 no.3
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• pp.221-233
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• 2014

In this study, we analyzed verbal interactions among 32 students in 7th graders' science cooperative learning at the levels of turns, interaction units, and conflict behavior units, and compared their verbal interaction patterns between the heterogeneous and homogeneous groups by students' collectivism. The relationships of verbal interactions with the achievement test scores and the increase of the achievement test scores were also investigated. In the analyses of turns, the distributions of the subcategories of the statements related to the task were found to be similar in both groups, and the frequency of 'explain' was highest. The frequencies of interaction units were higher in the homogeneous groups than the heterogeneous groups, and the frequency of 'symmetric interaction' was highest. In the heterogeneous groups, the frequencies of turns and interaction units for the students of high collectivism were higher than those of low collectivism. The frequencies of conflict behavior units were generally low, but the rates were similar in both groups. In the case of the homogeneous groups, the frequencies of 'avoiding' and 'competing' for the students of low collectivism were high, and the frequency of 'cooperating' for the students of high collectivism was high. In addition, the qualitative differences between the two groups were found in the interaction units and conflict behavior units. The achievement test scores and the increase of the achievement test scores were positively related with the sum of the frequencies of the statements related to the task.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.6
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• pp.173-180
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• 2021

Non Orthogonal Multiple Access (NOMA) is a technology to guarantee the explosively increased Quality of Service(QoS) of users in 5G networks. NOMA can remove the frequent orthogonality in Orthogonal Multiple Access (OMA) while allocating the power differentially to classify user signals. NOMA can guarantee higher communication speed than OMA. However, the NOMA has one disadvantage; it consumes a more energy power when the distance increases. To solve this problem, relay nodes are employed to implement the cooperative NOMA control idea. In a cooperative NOMA network, relay node participations for cooperative communications are essential. In this paper, a new bandwidth allocation scheme is proposed for cooperative NOMA platform. By employing the idea of Vickrey-Clarke-Groves (VCG) mechanism, the proposed scheme can effectively prevent selfishly actions of relay nodes in the cooperative NOMA network. Especially, base stations can pay incentives to relay nodes as much as the contributes of relay nodes. Therefore, the proposed scheme can control the selfish behavior of relay nodes to improve the overall system performance.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.149.1-149
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• 2001

In multi robot environment, the action selection strategy is important for the cooperation and coordination of multi agents. However the overlap of actions selected individually by each robot makes the acquisition of cooperation behaviors less efficient. In addition to that, a complex and dynamic environment makes cooperation even more difficult. So in this paper, we propose a control algorithm which enables each robot to determine the action for the effective cooperation in multi-robot system. Here, we propose cooperative algorithm with reinforcement learning to determine the action selection In this paper, when the environment changes, each robot selects an appropriate behavior strategy intelligently. We employ ...

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.1
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• pp.21-27
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• 2012

We can efficiently collect crops or minerals by operating multi-robot foraging. As foraging spaces become wider, control algorithms demand scalability and reliability. Swarm robotics is a state-of-the-art algorithm on wide foraging spaces due to its advantages, such as self-organization, robustness, and flexibility. However, high initial and operating costs are main barriers in performing multi-robot foraging system. In this paper, we propose a novel method to improve the energy efficiency of the system to reduce operating costs. The idea is to employ a new behavior model regarding role division in concert with the search space division.