• Journal of Korean Academy of Nursing
• /
• v.31 no.4
• /
• pp.571-583
• /
• 2001

Purpose: The purpose of this study was to examine the levels of burnout experienced by Korean hospital nurses (N=198), and to identify predictors of their nursing outcomes such as job performance, work satisfaction, and productivity. Method: Hierarchical multiple regression was used to identify predictors of each nursing outcomes. Included predictors were nurses' general characteristics, work- related characteristics (role stress and perceived control), and burnout. Results: Korean nurses experienced higher levels of burnout compared to the cutoffs suggested by Maslach and Jackson (1986) and to those in the USA. For each nursing outcome, predictor variables explained 39% of the variance in role performance, 30% of the variance in work satisfaction, and 38% of variance in productivity. Higher personal accomplishment, lower role ambiguity, being staff nurses, and lower emotional exhaustion were related to higher job performance, and higher productivity. Lower role conflict and role ambiguity were also related to higher work satisfaction. Conclusion: Based on the findings of this study, managemental interventions for nurses to reduce their burnout experience are needed. Further study in this area is warranted.

• Journal of electromagnetic engineering and science
• /
• v.15 no.4
• /
• pp.219-223
• /
• 2015

In this paper, a miniaturized radio frequency choke (RFC) using modified stubs is proposed to improve isolation characteristics in a multiple-input-multiple-output (MIMO) antenna system. The proposed RFC, based on the LC resonance, is designed to suppress the leakage current that leads to the degradation of antenna diversity performances in the MIMO antenna configuration. The proposed RFC is composed of two open stubs that are implemented on the top of the ground plane and miniaturized by adding a slit structure on the ground plane. The MIMO antennas are also designed to verify isolation performance in the LTE 2300 band (2,300-2,400 MHz). The MIMO antennas perform well with low reflection coefficient characteristics and high isolation characteristics in the whole LTE 2300 band. To evaluate the isolation in the MIMO system, the envelope correlation coefficient (ECC) is calculated, and the value is less than 0.08. The achieved ECC is regarded as a reasonable result for improving isolation performance in the frequency range of 2,300-2,400 MHz; also, radiation patterns of antenna elements are maintained regardless of the presence of RFC.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.5C
• /
• pp.355-363
• /
• 2005

This paper is discussed about the technology of the performance enhancement in the wireless communication between indoor and outdoor environments. In the outdoor wireless communication, the signal has mainly a severe degradation by the fading effect of channel, but that problem may be overcome by using ordinary multiple antenna technology and array signal processing algorithm. Hence, since the channel has the characteristics of both fading and angle spread in the wireless communication between indoor and outdoor, the ordinary technology cannot solve the signal degradation due to the angle spread. In order to solve the problem, in this paper, the characteristic of the wireless channel between indoor and outdoor is first analyzed and considered the channel models fit to that case. We propose the new multiple antenna algorithm by use of mean steering vector concept, and obtained the results of the performance enhancement. With the results of the performance analyses through of the numerical study and computer simulation, we show that the proposed algorithm has more enhanced signal to noise ratio than the previous algorithm.

• Korean Journal of Health Education and Promotion
• /
• v.23 no.4
• /
• pp.89-104
• /
• 2006

Objectives: This study was done to find factors related with performance of hepatitis B Vaccination among some aged persons through health belief model. Methods: A questionnaire survey was made during September 2004 toward 230 elderly persons using institutions for the elderly of Gwangju City. The relations between subjects characteristics including health belief, mass media contact, hepatitis B experience and performance of hepatitis B vaccination were tested by t test or X2 test. Multiple logistic regression analysis was done to find final significantly related variables. Results: 24.8% of the subjects were vaccinated against hepatitis B. By simple analysis of relation between performance of hepatitis B vaccination and subjects characteristics including health belief, significant variables were chosen as 6 variables including perceived susceptibility, perceived seriousness, perception of benefits, knowledge on hepatitis B, age, experience of hepatitis through family or friend. After adjusting for confounding variables by multiple logistic regression analysis, hepatitis B vaccine performance showed significantly higher rate as the perception of disease seriousness increased(OR: 1.08, 95% CI: $1.03{\sim}1.14$) and in the group contacted with TV or radio information about hepatitis compared with non-contact. The group who experienced hepatitis among family or friends showed significantly higher hepatitis B vaccination performance rate compared with non-experienced. Conclusion: These results suggested that hepatitis B vaccine performance was related with health belief including hepatitis susceptibility, disease seriousness perception, acquisition of information through TV or radio and indirect hepatitis experience from family or friends.

• Journal of information and communication convergence engineering
• /
• v.1 no.1
• /
• pp.1-5
• /
• 2003

This paper discusses the spectral efficiency and performance of asynchronous direct sequency spread spectrum multiple access systems strict bandwidth limitation by Nyquist filtering. The signal to noise plus interference ratio(SNIR) at the output from the correlation receiver is derived analytically taking the cross correlation characteristics of spreading sequences into account, and also an approximated SNIR of a simple form is presented for the systems employing Gold sequences. Based on the analyzed result of SNIR, bit error rate performance and spectral efficiency are also estimated. and at last, we analyzed improvement rate using RS, convolution as a method for improving functions.

• Journal of Information Technology Applications and Management
• /
• v.24 no.4
• /
• pp.215-227
• /
• 2017

The development of information technology are leading to the rapid evolution of SNS (Social Networking Services) in various directions and industries. Initially, SNS have been used as the form of networking between user's groups. Currently SNS has been developed towards multiple purposes and platforms such as the promotion and the advertising of a company. There are many SNSs including QQ, Weibo, and Wechat and so on in China. However, the use of companies in terms of advertising and information sharing with the customers do not meet the trend in China. Especially, there were little researches for Chinese travel agencies how to utilize SNS for attracting new customers and making them contribute to the firm's performance. In this study, we try to investigate the impact of the firm's characteristics and the usage of SNS on the performance of Chinese travel agencies. Based on Top 100 China travel agencies in 2009, we analyzed the relationships between firm's characteristics and the usage of SNS, and firm's performances in 2013. We expect that our study can contribute to the increasing academic and practical needs on the empirical evidence of the impacts of the SNS utilizations on the firm's performance.

• International Journal of Contents
• /
• v.7 no.4
• /
• pp.44-49
• /
• 2011

The scattering solutions for multiple rectangular metallic gratings in a perfectly conducting plane excited by the TE and TM delta sources are presented using an overlapping T-block method. A reflectarray composed of rectangular metallic gratings shows fanbeam radiation patterns that are useful for an electromagnetic fence. The scattering characteristics of multiple rectangular gratings were computed in terms of total radiated power and antenna directivity. The design method of a fan-beam reflectarray to obtain high directivity was also compared with superdirective radiation and parabolic reflector phase.

• ETRI Journal
• /
• v.31 no.1
• /
• pp.83-85
• /
• 2009

Compared with unicast, multicast over wireless ad-hoc networks do not support reliability due to their inability to exchange request-to-send/clear-to-send (RTS/CTS) and ACK packets with multiple recipients. Although several media access control (MAC) layer protocols have been proposed to provide reliable multicast, these introduce additional overhead, which degrades system performance. A novel MAC protocol for reliable wireless multicast is proposed in this paper. By adapting orthogonal frequency division multiple access characteristics in CTS and ACK packets, the protocol achieves reliability over wireless multicast with minimized overhead.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.33 no.12
• /
• pp.480-484
• /
• 1984

A speed control system of multiple induction motors is presented in this paper. The system consists of a single CSI, several wound retor type induction motors, and the choppers which control the rotor current of motors. Some performance characteristics are studied, and the closed control loop is suggested.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.5 s.120
• /
• pp.471-477
• /
• 2007

This paper presents the characteristics of electromagnetic field uniformity in a reverberation chamber with flat diffusers composed of multiple dielectric materials that can be used as an alternative facility for the analysis, test and evaluation of electromagnetic interference and immunity. The field characteristics and the size of the test volume inside the reverberation chamber with the new diffuser of multiple dielectric materials are simulated and analyzed at $2.5{\sim}3$ GHz band. The FDTD method is used to analyze the field characteristics. The field uniformity, polarization characteristics and tolerance are improved by the new diffuser with smaller physical size. The reverberation chamber with flat diffusers composed of multiple dielectric materials shows better electromagnetic performance and larger test volume than normal chamber.