• Journal of Auto-vehicle Safety Association
• /
• v.15 no.2
• /
• pp.28-34
• /
• 2023

The Republic of Korea aims to complete the commercialisation of Level 4+ cooperative autonomous driving in 2027. It also plans to include V2X OBU in the K-NCAP evaluation items. Therefore, communication performance safety evaluation criteria for V2X OBU need to be established, and an OBU with necessary functions is needed to develop V2X communication performance safety evaluation technology for vehicles. In this study, we implemented a V2X OBU control board prototype that can be used to develop a V2X communication performance safety evaluation technology for Level 4+ autonomous vehicles, and confirmed that the control board prototype works normally.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10b
• /
• pp.70-75
• /
• 1993

We represent a method of 3-D object recognition using multi images in this paper. The recognition process is executed as follows. Object models as prior knowledgement are generated and stored on a computer. To extract features of a recognized object, three CCD cameras are set at vertices of a regular triangle and take images of an object to be recognized. By comparing extracted features with generated models, the object is recognized. In general, it is difficult to recognize 3-D objects because there are the following problems such as how to make the correspondence to both stereo images, generate and store an object model according to a recognition process, and effectively collate information gotten from input images. We resolve these problems using the method that the collation on the basis of features independent on the viewpoint, the generation of object models as enumerating some candidate models in an early recognition level, the execution a tight cooperative process among results gained by analyzing each image. We have made experiments based on real images in which polyhedral objects are used as objects to be recognized. Some of results reveal the usefulness of the proposed method.

• ETRI Journal
• /
• v.36 no.1
• /
• pp.31-41
• /
• 2014

The heterogeneous network (HetNet) has been discussed in detail in the Long-Term Evolution (LTE) and LTE Advanced standards. However, the standardization of High-Speed Packet Access HetNet (HSPA HetNet) launched by 3GPP is pushing at full steam. Interference coordination (IC), which is responsible for dealing with the interference in the system, remains a subject worthy of investigation in regard to HSPA HetNet. In this paper, considering the network framework of HSPA HetNet, we propose a quasi-distributed IC (QDIC) scheme to lower the interference level in the co-channel HSPA HetNet. Our QDIC scheme is constructed as slightly different energy-efficient non-cooperative games in the downlink (DL) and uplink (UL) scenarios, respectively. The existence and uniqueness of the equilibrium for these games are first revealed. Then, we derive the closed-form best responses of these games. A feasible implementation is finally developed to achieve our QDIC scheme in the practical DL and UL. Simulation results show the notable benefits of our scheme, which can indeed control the interference level and enhance the system performance.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.7
• /
• pp.2354-2370
• /
• 2015

The advantages of employing SCTP-based Concurrent Multipath Transfer (CMT) have been demonstrated to be very useful for data delivery over multi-homed wireless networks. However, there is still significant ongoing work addressing some remaining limitations and challenges. The most important concern when applying CMT to data delivery is related to handling packet reordering and buffer blocking. Another concern on this topic is that current sender-based CMT solutions seldom consider balancing the overhead and sharing the load between the sender and receiver. This paper proposes a novel Receiver-driven Cooperation-based Concurrent Multipath Transfer solution (CMT-Rev) with the following aims: (i) to balance overhead and share load between the sender and receiver, by moving some functions including congestion and flow control from the sender onto receiver; (ii) to mitigate the data reordering and buffer blocking problems, by using an adaptive receiver-cooperative path aggregation model, (iii) to adaptively transmit packets over multiple paths according to their receiver-inspired sending rate values, by employing a new receiver-aware data distribution scheduler. Simulation results show that CMT-Rev outperforms the existing CMT solutions in terms of data delivery performance.

• English Language & Literature Teaching
• /
• v.11 no.3
• /
• pp.89-112
• /
• 2005

This study investigated the effects of collocation-based vocabulary instruction for the experimental group (G2). It was compared to the traditional wordlist-based vocabulary instruction for the control group (G1). This results reflect the development of low level high school EFL learners' vocabulary learning strategy use and the positive change in the affective domain. In the analysis of the survey responses, G1 and G2 did not differ significantly on the first questionnaire. They did, however, differ significantly on the second questionnaire. G2 used more strategies to discover and to consolidate the meaning of the words by means of combining words. In terms of the affective domain, G2 participated more actively in the learning activities, which had a significant effect on vocabulary growth, memory, self-confidence, motivation, and cooperative learning. This is attributable to the fact that G2 was more inquisitive, interested, challenged, participatory, cooperative, and attentive than G1 in performing the vocabulary task activities. Moreover, the data collected from the questionnaire showed that G2 performed more interactive and dynamic activities in solving the given tasks.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.36S no.6
• /
• pp.67-75
• /
• 1999

The sensing and communication abilities of a mobile robot are essential to cooperative behavior in distributed autonomous robotic systems. In general, as the number of robot goes on increasing, the limitation of communication capacity and information overflow occur in global communication capacity and information overflow occur in global communication system. Therefore a local communication is more effective than global one. In this paper, we analyze information propagation mechanism based on local communication. To find an optimal communication radius, we propose three methods with different conditions. Also, to avoid chaotic behavior which occurs when a robot obtains and loses information, we find stable condition of information propagation.

• International Commerce and Information Review
• /
• v.10 no.2
• /
• pp.391-410
• /
• 2008

Emphasis on relationship management might be found out from Williamson (1975), who tried to elucidate why an organization exists. According to his transaction cost theory, an organization is established to evade opportunistic actions of the market and build up a hierarchy of value chain. However, judged from the perspective of exchange relationship in a trade, the transaction cost theory was likely to approach to buyer-seller relationship by the mechanism of competition. Therefore, an organization exists to control the competition of the market. Relationship management suggested by relationship marketing focuses on cooperation between buyers and sellers, rather than competition against each other. Relationship management aims to provide a framework for making a market relationship that might become an asset or a resource of the firm. In the process of maintaining and strengthening long-term and cooperative relationship with all stakeholders included customers, suppliers and staff, they continue to create new values. The purpose of this empirical research, by investigating how relationship management of multinational enterprises influences on their competitive advantages and performances, is to suggest that a cooperative relationship established for a long time in the market, so-called quasi-market relationship, substitutes for an organization.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.11
• /
• pp.1013-1020
• /
• 2011

This paper deals with the tracking problem of a moving target using multiple unmanned aerial vehicles. A decentralized extended information filter is designed to cooperatively estimate the position and the velocity of the moving target. The extended information filter is adopted to consider the range and the line-of-sight angle as measurement data. The decentralized scheme is applied to enhance the estimation performance using the information provided by other vehicles. Numerical simulation is performed to verify the tracking performance of the proposed decentralized filters.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.12
• /
• pp.5212-5230
• /
• 2016

How to determine the right number of small base stations to activate in multi-cell uplinks to match traffic from a fixed quantity of K users is an open question. This paper analyses the uplink cooperative that jointly receives base stations activation to explore this question. This paper is different from existing works only consider transmitting power as optimization objective function. The global objective function is formulated as a summation of two terms: transmitting power for data and coordinated overhead for control. Then, the joint base stations activation and beamforming problem is formulated as a mixed integer second order cone optimization. To solve this problem, we develop two polynomial-time distributed methods. Method one is a two-stage solution which activates no more than K small base stations (SBSs). Method two is a heuristic algorithm by dual decomposition to MI-SOCP that activates more SBSs to obtain multiple-antennae diversity gains. Thanks to the parallel computation for each node, our methods are more computationally efficient. The strengths and weaknesses of these two proposed two algorithms are also compared using numerical results.

• Journal of Agricultural Extension & Community Development
• /
• v.18 no.4
• /
• pp.793-824
• /
• 2011

This study is to explore implications for sustainable development of Yangdong Village in Gyeongju through identifying effect of its designation as a World Cultural Heritage on residents' quality of life. The following are the findings achieved by empirical analysis. First, eight valuable factors of placeness were identified through factor analysis, about which residents were especially conscious in terms of "living condition", "cultural environment", "economic QOL", "natural environment conservation", "sense of community", "cooperative facilities", "control over increasing population", "transport environment". Second, the importance -satisfaction scores of identified 8 factors were found very high in importance showing relatively low level of low level of satisfaction. Especially, what caused residents's low QOL was economic status-concerned factor showing the lowest QOL index, and other factors such as cooperative facilities and transport environment negatively impacted on resident's QOL as well. Also, it was revealed that residents had a positive attitude toward entering of their village into UNESCO world heritage sites with hope that it would improve their economic QOL. Based on these results, implications for sustainability of Yangdong Village and research limitations were discussed, and further research direction was supposed.