• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.3134-3155
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• 2020

In this paper, we study the joint radio and computational resource allocation in the ultra-dense mobile-edge computing networks. In which, the scenario which including both computation offloading and communication service is discussed. That is, some mobile users ask for computation offloading, while the others ask for communication with the minimum communication rate requirements. We formulate the problem as a joint channel assignment, power control and computational resource allocation to minimize the offloading cost of computing offloading, with the precondition that the transmission rate of communication nodes are satisfied. Since the formulated problem is a mixed-integer nonlinear programming (MINLP), which is NP-hard. By leveraging the particular mathematical structure of the problem, i.e., the computational resource allocation variable is independent with other variables in the objective function and constraints, and then the original problem is decomposed into a computational resource allocation subproblem and a joint channel assignment and power allocation subproblem. Since the former is a convex programming, the KKT (Karush-Kuhn-Tucker) conditions can be used to find the closed optimal solution. For the latter, which is still NP-hard, is further decomposed into two subproblems, i.e., the power allocation and the channel assignment, to optimize alternatively. Finally, two heuristic algorithms are proposed, i.e., the Co-channel Equal Power allocation algorithm (CEP) and the Enhanced CEP (ECEP) algorithm to obtain the suboptimal solutions. Numerical results are presented at last to verify the performance of the proposed algorithms.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.9
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• pp.1216-1223
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• 2018

As field of application of AMI, AMR uses the power line as the primary means of communication. PLC has a big merit without installation of the new network for communication in a field using the power line which is the existing equipment. However, there is a serious obstacle in commercialization for the instability by noise and communication environment. Therefore, the technical method for maintaining the communication state which overcome such demerit and was stabilized is required essentially. PLC routing technology is applied with the alternative plan now. The routing technology currently managed by field includes many problems by applying the algorithm of an elementary level. PLC routing path search problem can be modeled with the problem of searching for optimal solution as similar to such as optimal routing problem and TSP(Travelling salesman problem). In this paper, in order to search for a PLC routing path efficiently and to choose the optimal path, GA(Genetic Algorithm) was applied. Although PLC was similar in optimal solution search as compared with typical GA, it also has a difference point by the characteristic of communication, and presented the new methodology over this. Moreover, the validity of application technology was verified by showing the experimental result to which GA is applied and analyzing as compared with the existing algorithm.

• Journal of the Korean Graphic Arts Communication Society
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• v.8 no.1
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• pp.71-87
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• 1990

This paper presents a simple algorithm to obtain three dimensional information of an object. In the preprocessing of the stereo matching,feature point informations of stero image must be less sensitive to noise and well liked the correspondance problem. This paper described a simple technique of struture feature extraction of 3-D object and used edge-end point expanding method for unconnected line instade of Hough transform. The feature such as corner point and their angles are used for matching problem. The experimental results show that the described algorithm is a useful method for stereo correspondence problem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.389-398
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• 2018

This study examined the influence of problem solving ability, communication skill and self-efficacy on clinical competence of nursing students. The research subjects were 184 grade 4 nursing students in D and G city. Data were collected from September 1 to September 10, 2016 and analyzed by independent t-test, one-way ANOVA, Pearson's correlation, and stepwise multiple regression using the IBM SPSS/WIN 20.0 program. The results showed that the problem solving ability was 3.60, communication skill was 3.79, and self-efficacy was 3.45. The clinical competence was positively correlated with problem solving ability, communication skill and self-efficacy. Problem solving ability (${\beta}=0.283$, p<0.001), self-efficacy (${\beta}=0.249$, p<0.001), motivation for nursing (${\beta}=0.182$, p=0.002), communication skills (${\beta}=0.176$, p=0.016), and interpersonal relationships (${\beta}=0.101$, p=0.082) explained 42.8% of the total variance in clinical competence of nursing students. The most significant predictors of clinical competence were problem solving ability, followed by self-efficacy and communication skills. Therefore, it is necessary to develop an empowerment program to improve problem solving ability, self-efficacy and communication skills of nursing students.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.155-166
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• 2021

The purpose of this study was to investigate the effects of empathy and communication skills on nursing problem-solving skills of nursing students who received simulation classes. The subjects of this study were composed of 234 students in the 3rd and 4th grades who already took simulation classes. The data was collected from April 26th to May 10th, 2021. The data was analyzed with the SPSS WIN 25.0 program. Descriptive statistics and mean differences were analyzed using an independent t-test, one-way ANOVA, Pearson's correlation coefficient, and multiple regression. As a result, the average points of empathy skills were 5.29 out of 7, communication skills were 3.30 out of 5, and problem-solving skills were 3.51 out of 5. Empathy skills and communication skills were positively correlated with problem-solving skills. The predicting factors on problem-solving skills were empathy and communication skills, on-campus practice period, and gender in order. The explanatory power of these factors was 64.6%. In conclusion, in order to improve the problem-solving ability of nursing students, a strategy is needed to enhance empathy and communication skills through continuous simulation classes.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.417-427
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• 2017

Power allocation is an important factor for cognitive radio networks to achieve higher communication capacity and faster equilibrium. This paper considers power allocation problem to each cognitive user to maximize capacity of the cognitive systems subject to the constraints on the total power of each cognitive user and the interference levels of the primary user. Since this power control problem can be formulated as a mixed-integer nonlinear programming (NP) equivalent to variational inequality (VI) problem in convex polyhedron which can be transformed into complementary problem (CP), we utilize modified projection method to solve this CP problem instead of finding NP solution and give a power control allocation algorithm with a subcarrier allocation scheme. Simulation results show that the proposed algorithm performs well and effectively reduces the system power consumption with almost maximum capacity while achieve Nash equilibrium.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.480-489
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• 2016

Hidden station problem can occur in power-line communication (PLC) networks. A simple solution to the problem has been proposed to use request-to-send (RTS)/clear-to-send (CTS) exchange, but this approach cannot solve the hidden station problem perfectly. This paper revisits the problem for PLC networks and designs a protocol to solve it. We first analyze the throughput performance degradation when the hidden station problem occurs in PLC networks. Then, we propose an interferer aware multiple access (IAMA) protocol to enhance throughput and fairness performances, which uses unique characteristics of PLC networks. Using the RTS/CTS exchange adaptively, the IAMA protocol protects receiving stations from being interfered with neighboring networks. Through extensive simulations, we show that our proposed protocol outperforms conventional random access protocols in terms of throughput and fairness.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.243-247
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• 2009

For obtaining high speed data rate, underwater acoustic communication has several problems by the different environmental problem compared to wireless communication. To overcome this problem, the research is going steadily. In this paper, the property of underwater acoustic channel is considered, and the explanation of recently various method of transmitting and receiving and the domestic and foreign trend of underwater acoustic communication are taken into account.

• International Journal of Contents
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• v.10 no.4
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• pp.69-74
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• 2014

General location aware systems are only applied to indoor and outdoor environments using more than three transmitters to estimate a fixed object location. Those kinds of systems have environmental restrictions that require an already established infrastructure. To solve this problem, an Object Location Estimation (OLE) algorithm based on PTP (Point To Point) communication has been proposed. However, the problem with this method is that deduction of performance parameters is not enough and location estimation is very difficult because of unknown restriction conditions. From experimental tests in this research, we determined that the performance parameters for restriction conditions are a maximum transmission distance of CSS communication and an optimum moving distance interval between personal locations. In this paper, a system applied OLE algorithm based on PTP communication is implemented using a CSS (Chirp Spread Spectrum) communication module. A maximum transmission distance for CSS communication and an optimum moving distance interval between personal locations are then deducted and studied to estimate a fixed object location for generalization.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.3
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• pp.173-181
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• 2016

Several falling-sensing terminals have been developed which are able to detect the fall/upset accident of the elderly and transmit the collapsing signals to the administrative server via RF communication using 400MHz bandwidth. Supposing there might be no communication problem within a sanatorium, just single terminal without relay function had been made as a prototype in the first stage of development. However some communication problems have discovered at the coner of the floor apart from the other floor diagonally in the same building. Same kind of problems have been happened in the area behind a steel fence or a car. To solve these kinds of communication problems, we have developed several terminals and added up relay function to them. In this paper we represented that the success ratio of the communication has been improved by using relay function among several terminals.