• Journal of electromagnetic engineering and science
• /
• v.8 no.2
• /
• pp.41-46
• /
• 2008

A bandwidth and power efficient high speed ubiquitous sensor network(USN) for realizing a ubiquitous society is a great challenge for researcher community. In this paper we incorporate a cooperative transmission protocol within a special type of multi-code modulation to meet these requirements. Multi-code(Mc) modulation has been developed for high-speed data transmission over wireless channels. We proposed a new class of orthogonal codes for multi-code modulation which is an orthogonal subset of orthogonal codes(OSOC). Our proposed OSOC structure allows us to use only one relay to cooperate M nodes that effectively reduces the bandwidth and power requirement. This protocol is similar to spread-spectrum(SS) technique that can reduce both broad and narrow band jamming.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.8
• /
• pp.948-954
• /
• 1999

In this paper, we propose a cooperative motion planning algorithm for two tightly-coupled mobile robots. Specifically, the considered cooperative work is that two mobile robots should transfer a long rigid object along a predefined path. To resolve the problem, we introduce a master-slave concept for two obile robots having the same structure. According to the velocity of the master robot and the positions of two robots on the path, the velocity of the slave robot is determined. The slave normally tracks the master's motion, but in case that the velocity of the slave exceeds the velocity limit, the roles of the robots should be interchanged. The effectiveness of the proposed algorithm is proved by computer simulations.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.11a
• /
• pp.8-9
• /
• 2020

While non-uniform shapes are appearing as an apparent building style recently, most architects predominantly think structure and construction technology should support the designed shape of non-uniform structures determined by the architect. Within such a governance structure of architect's perception, the role of an engineer is emphasized for technical support only. Especially, in making a decision on a structural design and plan, if various and objective reviews are not conducted, the design is very likely to be left only as a drawing even if the design is appropriate for criteria and norms. With the recognition of such problems, the present study attempted to propose an equal cooperative relationship between architects and engineers in designing non-uniform structures in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.10
• /
• pp.4873-4888
• /
• 2018

A joint blind parameter estimation algorithm based on minimum channel stability function aimed at the non-cooperative high-order modulated paired carrier multiple access (PCMA) signals is proposed. The method, which uses hierarchical search to estimate time delay, amplitude and frequency offset and the estimation of phase offset, including finite ambiguity, is presented simultaneously based on the derivation of the channel stability function. In this work, the structure of hierarchical iterative processing is used to enhance the performance of the algorithm, and the improved algorithm is used to reduce complexity. Compared with existing data-aided algorithms, this algorithm does not require a priori information. Therefore, it has significant advantage in solving the problem of blind parameter estimation of non-cooperative high-order modulated PCMA signals. Simulation results show the performance of the proposed algorithm is similar to the modified Cramer-Rao bound (MCRB) when the signal-to-noise ratio is larger than 16 dB. The simulation results also verify the practicality of the proposed algorithm.

• Journal of Fisheries and Marine Sciences Education
• /
• v.20 no.2
• /
• pp.297-308
• /
• 2008

This study developed career education program applying cooperative learning structures (Kagan, 1993, 1995, 1997), and tested its effect on elementary school children's career development. Sixth grade students of 2 classes were divided into experimental and control group, and 14 sessions of the program were applied to the experimental group for 8 weeks. Career development test(Lee, 2005) were performed before and after the program. Students in both groups were retested 3 months after the post-test to test continuing effects of the program. Score tendencies and their differences between experimental group and control group of children in 3 career development areas - self-awareness, educational and occupational exploration, and career planing - were tested and the results are as follows: development of 3 areas of self-awareness, educational and occupational exploration, and career planing were consistently increasing along the experimental sequence in experimental group, while the development of 3 areas showed no changes or declining tendencies in control group. Self-awareness and educational and occupational exploration did not show the statistically significant differences between the groups. Meanwhile, the career plaining showed statistically significant difference between the groups in post-test, meaning that the career education program with cooperative structure has positive effects on the career planing in 6th grade students.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.9
• /
• pp.4180-4196
• /
• 2017

In this paper, we analyze average capacity of an amplify-and-forward (AF) cooperative communication system model in multi-relay multiuser networks. In contrast to conventional cooperative networks, relays in the considered network have no embedded energy supply. They need to rely on the energy harvested from the signals broadcasted by the source for their cooperative information transmission. Based on this structure, a two-step selection scheme is proposed considering both channel state information (CSI) and battery status of relays. Assuming each relay has infinite or finite energy storage for accumulating the energy, we use the infinite or finite Markov chain to capture the evolution of relay batteries and certain simplified assumptions to reduce computational complexity of the Markov chain analysis. The approximate closed-form expressions for the average capacity of the proposed scheme are derived. All theoretical results are validated by numerical simulations. The impacts of the system parameters, such as relay or user number, energy harvesting threshold and battery size, on the capacity performance are extensively investigated. Results show that although the performance of our scheme is inferior to the optimal joint selection scheme, it is still a practical scheme because its complexity is much lower than that of the optimal scheme.

• Journal of the Korean housing association
• /
• v.14 no.6
• /
• pp.193-204
• /
• 2003

In connection with the plan for improving the residential environment gradually by analyzing the present condition of the reconstruction and parcel form of the housing area in a inner area, the main objective of this research is to develop a cooperative urban housing model based on the neighborhood agreement. The parcel form has a structure that is inappropriate for individual reconstruction； thus, the substantial improvement only through the residential environment improvement project has its limitations. As an alternative plan to resolve such limitations, I proposed a system that enables step-by-step reconstruction within the small-scaled blocks through the annexation of the land based on the neighborhood agreement. Nonetheless, I realized that it is difficult to apply such reconstruction system to individual housing. Therefore, I presented a design concept on the cooperative urban housing project as a residential form for the reconstruction inside blocks. A model plan vouches for its effectiveness. To apply substantially the cooperative urban housing plan based on the neighborhood agreement, we need to supplement the sectional plan system.

• Journal of KIISE
• /
• v.42 no.5
• /
• pp.671-680
• /
• 2015

Numerous clustering schemes have been proposed to increase energy efficiency in wireless sensor networks. Clustering schemes consist of a hierarchical structure in the sensor network to aggregate and transmit data. However, existing clustering schemes are not suitable for use in wireless multimedia sensor networks because they consume a large quantity of energy and have extremely short lifetime. To address this problem, we propose the Energy-Aware Cooperative Communication (EACC) method which is a novel cooperative clustering method that systematically adapts to various types of multimedia data including images and video. An evaluation of its performance shows that the proposed method is up to 2.5 times more energy-efficient than the existing clustering schemes.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.1288-1293
• /
• 2009

Performing 'Mega Project' in which various stakeholders are involved is difficult to control due to the respective conflicting objectives. Urban regeneration which is being challenged issue in various ways can be defined as the mega project. Since the mega project like urban regeneration a long-continued project and includes a lot of participants whose benefits conflict, cooperation among stakeholders is essential. Moreover, as the project goes, diverse decision making situations which require collaboration happen, and if proper decision making cannot be given at that time, the whole project would have critical effects. Also, since each activity concerns numerous stakeholders, prompt decision making is difficult in the mega project. Therefore, the objective of this study is to support stakeholder's cooperative decision making in order for conducting successful project. For the purpose of the paper, the concept of cooperation in mega project is redefined and a cooperative decision making framework is suggested. Also, the term of governance, which means cooperative mechanism based on the mutual trust, information sharing and partnership, is applied to the newly defined cooperation. The suggested cooperative decision making framework contains the structure of stakeholders in urban regeneration project which enables participants to understand the relationship among bodies and checklists for supporting decision making appropriately. The application of the framework proposed in this research is expected to contribute subjects' suitable decision making by providing proper information in a timely manner.

• 한국유가공학회:학술대회논문집
• /
• 1998.11a
• /
• pp.29-36
• /
• 1998