• Journal of Korean Academy of Nursing Administration
• /
• v.16 no.4
• /
• pp.488-496
• /
• 2010

Purpose: This study was done to explore the relationship in hospital nurses' of communication competence, communication types, and organizational commitment and to provide basic data for developing programs to improve internal communication and to promote nurses' commitment to their organizations. Methods: The participants included 316 nurses who worked in two general hospitals. The tools used for this study were the Global Interpersonal Communication Competence Scale (GICC) and Communication Satisfaction Questionnaire by Downs & Hazen (1981), revised by Seo (2002) and Mowday's tool (1979) for organizational commitment. Data were analyzed using SPSS/PC+12.0. Results: The mean score for communication competence was 3.46, and for organizational commitment, 3.19. For communication types, the mean score for formal communication was 3.18 and informal communication, 2.59. Communication competence had a positive relationship with formal communication (r=.32) and with informal communication (r=.16). Organizational commitment had a positive relationship with formal communication (r=.53), communication competence (r=.30), and informal communication (r=.27). Conclusion: The results indicate the necessity of developing programs to promote nurses' communication competence and also developing a system that will enrich active communication. Systematic and continuous training in communication is also highly recommended.

• International Journal of Contents
• /
• v.8 no.2
• /
• pp.13-18
• /
• 2012

In wireless sensor networks, an energy efficient data gathering scheme is one of core technologies to process a query. The cluster-based data gathering methods minimize the energy consumption of sensor nodes by maximizing the efficiency of data aggregation. However, since the existing clustering methods consider only uniform network environments, they are not suitable for the real world applications that sensor nodes can be distributed unevenly. To solve such a problem, we propose a balanced multi-hop clustering scheme in non-uniform wireless sensor networks. The proposed scheme constructs a cluster based on the logical distance to the cluster head using a min-distance hop count. To show the superiority of our proposed scheme, we compare it with the existing clustering schemes in sensor networks. Our experimental results show that our proposed scheme prolongs about 48% lifetime over the existing methods on average.

• Journal of Communications and Networks
• /
• v.18 no.5
• /
• pp.818-825
• /
• 2016

Network management and anomaly detection are challenges in high-speed networks due to the high volume of packets that has to be analysed. Flow-based analysis is a scalable method which reduces the high volume of network traffic by dividing it into flows. As sampling methods are extensively used in flow generators such as NetFlow, the impact of sampling on the performance of flow-based analysis needs to be investigated. Monitoring using sampled traffic is a well-studied research area, however, the impact of sampling on flow-based anomaly detection is a poorly researched area. This paper investigates flow sampling methods and shows that these methods have negative impact on flow-based anomaly detection. Therefore, we propose an efficient probabilistic flow sampling method that can preserve flow traffic distribution. The proposed sampling method takes into account two flow features: Destination IP address and octet. The destination IP addresses are sampled based on the number of received bytes. Our method provides efficient sampled traffic which has the required traffic features for both flow-based anomaly detection and monitoring. The proposed sampling method is evaluated using a number of generated flow-based datasets. The results show improvement in preserved malicious flows.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.2
• /
• pp.93-100
• /
• 2014

IEEE 802.11 Wireless LAN Medium Access Control(MAC) supports two transmission methods, a DCF basic and a RTS/CTS in contention-based access. Even though the RTS/CTS method has been optionally introduced to solve the hidden terminal problem, it is able to produce better performance in some network environments than the basic transmission method. In this paper, the collision probability of wireless channel is mathematically analyzed and applied to measure network throughput using real transmission parameters so that a reference value between throughputs of two methods is obtained. We also confirmed that control signal rates affect overall network throughput and evaluated network throughputs considering collision probability, number of stations, and contention window size of Backoff between two methods respectively.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.1
• /
• pp.37-44
• /
• 2013

In this paper, the characteristics of portable fuel cell system are introduced and the dynamic response of output voltage of fuel cell stack with internal humidifier is analyzed. When the output of the fuel cell (FC) stack is short-circuited for humidification, the output voltage of the FC stack rapidly drops. In order to maintain the load voltage in the required range, dynamic compensation methods are proposed: 1) installing a capacitor behind the output of the FC stack; 2) utilizing the bi-directional converter. Especially, bi-directional converter is used when short of the FC output is detected or predicted by algorithm using data which is measured during previous three cycles. These methods are simulated by PSIM 9.0, then experimental results from the fuel cell system prototype verify the validity of the proposed methods.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2007.02a
• /
• pp.35-39
• /
• 2007

We applied digital image processing about BitMap file structure in this research and studied about digital communication system. digital record saving devices can express 'High' and 'Low' as all data. Only, digital technique that two expression methods is used into several expenditures. People and communication that are far away by development of digital technology, became smooth. We wished to make communication system taking advantage of digi-tech. This system was made for communication with disabled and normal person specially. To communication method that we are studied such BitMap file handling image communication system. The goal of this contribution is to present the overview of basic algorithms for image processing using BitMap.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2004.05a
• /
• pp.280-281
• /
• 2004

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.11 s.102
• /
• pp.1147-1154
• /
• 2005

In this paper, we propose some PAPR(Peak to Average Power Ratio) reduction methods using WHT(Walsh Hadamard Transform) to reduce high PAPR generated in OFDM system because of multi carrier modulation. These proposed methods are the methods which has additional PAPR reduction performance without a loss of bandwidth efficiency and a large increment of calculation complexity than common PAPR reduction methods by combining the WHT with some common methods. In this paper, we propose two PAPR reduction methods made by combining a SLM(Selective Mapping) and DSI(Dummy Sequence Insertion) with a WHT. From simulation result, we can find that the PAPR reduction methods using a WHT can get about 1 dB additional PAPR reduction performance than common PAPR reduction methods; they are SLM and DSI. And, because our proposed methods have not only PAPR reduction effect, but also frequency diversity effect, more stabile data transmission is possible in nonlinear HPA and multipath fading channel.

• ETRI Journal
• /
• v.38 no.6
• /
• pp.1124-1134
• /
• 2016

The tone reservation method is one of the most effective pre-distortion methods for peak-to-average power ratio reduction in orthogonal frequency division multiplexing (OFDM) systems. Its direct application to OFDM systems with offset quadrature amplitude modulation (OQAM) is, however, not effective. In this paper, two novel TR-based methods are proposed, specifically designed for OFDM/OQAM systems by taking into consideration the overlapping nature of OQAM signals. These two methods have different approaches to the generation of the peak-cancelling signal. The first one (overlapped scaling tone reservation) generates the peak-cancelling signal using a least squares approximation algorithm with possible adjacent symbol overlap; the second one (multi-kernel tone reservation) generates the peak-cancelling signal by using multiple impulse-like time domain kernels. It is shown by simulation that, when used in OFDM/OQAM systems, the proposed methods can provide better performance than the direct application of the existing controlled clipping tone reservation method, and even outperform the multi-block tone reservation method.

• The KIPS Transactions:PartA
• /
• v.12A no.3 s.93
• /
• pp.243-252
• /
• 2005

This paper introduces a noble modeling technique to build data communication prediction models in multiprocessors, using Least-Squares and Robust Estimation methods. A set of sample communication rates are collected by using a few small input data sets into workload programs. By applying estimation methods to these samples, we can build analytic models that precisely estimate communication rates for huge input data sets. The primary advantage is that, since the models depend only on data set size not on the specifications of target systems or workloads, they can be utilized to various systems and applications. In addition, the fact that the algorithmic behavioral characteristics of workloads are reflected into the models entitles them to model diverse other performance metrics. In this paper, we built models for cache miss rates which are the main causes of data communication in shared memory multiprocessor systems. The results present excellent prediction error rates; below $1\%$ for five cases out of 12, and about $3\%$ for the rest cases.