• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.765-769
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• 2011

The existing portable reference equipment for ITS systems performance evaluation has several limitations. First, it is difficult to set up and operate the equipment in the road section with the shoulder width equal to or smaller than 1.5m. Secondly, the crash with a car could lead to severe accident since it is big and heavy. Lastly, it cannot collect data from multiple lanes at a time. In this research the characteristics of the USN-based portable reference equipment developed to overcome shortcomings of the existing portable reference equipment were analyzed qualitatively and its performance level was evaluated through the field test. Consequently, the USN-based portable reference equipment turned out to overcome the operational shortcomings and satisfy the performance level required for the portable reference equipment.

• Journal of muscle and joint health
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• v.28 no.2
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• pp.192-199
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• 2021

Purpose: This study aimed to identify the influence of osteoporosis knowledge and health behavior self-efficacy on preventive nursing performance for osteoporosis. Methods: The participants of this study were 150 nurses working in 4 general hospitals. The data were collected during October 2019 using written questionnaires. General characteristics, osteoporosis knowledge, health behavior self-efficacy, and preventive nursing performance for osteoporosis were analyzed using means and standard deviation, t-test, ANOVA, Scheffé test, Pearson's correlation and multiple regression analysis. Results: As a result of multiple regression analysis, the factors affecting preventive nursing performance included osteoporosis prevention education (β=.16, p=.034) and health behavior self-efficacy (β=.51, p<.001). The explanatory power of the model was 31.5%(F=10.94, p<.001). Conclusion: It was found that the experiences of osteoporosis prevention education and health behavior self-efficacy influenced preventive nursing performance for osteoporosis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11A
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• pp.870-877
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• 2011

IEEE 802.11 devices are widely used, and terminals can be equipped with multiple IEEE 802.11 interfaces as low-cost IEEE 802.11 devices are deployed. The off-the-shelf IEEE 802.11 devices provide multiple channels and multiple data rates. In practical multi-channel networks, since there is channel heterogeneity which indicates that channels have different signal characteristics for the same node, channels should be efficiently assigned to improve network capacity. In addition, in multi-rate networks, low-rate links severely degrade the performance of high-rate links on the same channel, which is known as performance anomaly. Therefore, in this paper, we propose a heterogeneity aware channel assignment (HACA) algorithm that improves network performance by reflecting channel heterogeneity and performance anomaly. Through NS-2 simulations, we validate that the HACA algorithm shows improved performance compared with existing channel assignment algorithms that do not reflect channel heterogeneity.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.231-249
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• 2018

The purpose of this study is analyze the factors affecting the standard precaution(SP) performance on the knowledge, awareness, attitude and safety environment for SP of healthcare workers of general hospitals. The research method was a descriptive research study. The subject were 262 of healthcare workers of general hospitals. The data were analyzed using descriptive statistics, t-test, Chi-square test, ANOVA, Person's correlation coefficient and Multiple regression analysis using the SPSS program. As a result of the correlation analysis SP Performance was positively correlated with attitude (r=.18, p=.003), safety environment (r=.42, p<.001) and awareness (r=.63, p<.001). As a result of the stepwise multiple regression analysis on the factors influencing SP performance were SP awareness and safety environment. Therefore, in order to improved performance of SP, it's important to improve a awareness and safety environment of SP. Different and persistent infection management educational programs that consider the occupational characteristics and monitoring are required.

• Journal of Family Resource Management and Policy Review
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• v.6 no.1
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• pp.103-115
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• 2002

The purpose of this study was to analyze which factor, influenced the business and family performance success. Data were obtained from 248 family households. Proxy variable of the business performance was gross business income and of the family performance was the Family AFGAR scores. The multiple regression analysis was conducted for both the business performance equation and family performance equation. The main results of this study were as followings: The results indicated the effects of various business and family characteristics on performance and their contributions to the business and family performance model. Nine explanatory variables such as sex, being home-based, number of hours worked per week, number of family employee, number of nonfamily employee, total asset, the presence of young child under 6, nonbusiness income, and role conflicts were statistically significant in the business performance equation and three explanatory variables such as the hours worked per week, family stress scores, and role conflicts were statistically significant in the family performance equation. The results indicated the need for a more comprehensive view of family business performance.

• The Journal of the Acoustical Society of Korea
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• v.35 no.3
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• pp.167-174
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• 2016

Underwater communication is difficult to increase the communication capacity because the carrier frequency is lower than that of radio communications on land. This is limited to the bandwidth of the signal under the influence of the characteristics of an ocean medium. As the high transmission speed and large transmission capacity have become necessary in the limited frequency range, the studies on MIMO (Multiple Input Multiple Output) communication have been actively carried out. The performance of the MIMO communication is lower than that of the SIMO (Single Input Multiple Output) communication because cross-talk occurs due to multiusers along with inter symbol interference resulting from the channel characteristics such as delay spread and doppler spread. Although the adaptive equalizer considering multi-channels is used to mitigate the influence of the cross-talk, the algorithm is normally complicated. In this paper, time reversal mirror technique with the characteristic of a self-equalization will be applied to simplify the compensation algorithm and relieve the cross-talk in order to improve the communication performance when the signal transmitted from two channels is received over interference on one channel in the same time. In addition, the performance of the MIMO communication based on the time reversal mirror is verified using data from the SAVEX15(Shallow-water Acoustic Variability Experiment 2015) conducted at the northern area of East China Sea in May 2015.

• Journal of Distribution Science
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• v.22 no.3
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• pp.105-112
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• 2024

Purpose: This study analyzed the relationship between corporate capacity and management performance in the Korean distribution industry during the COVID-19 pandemic. Research design, data and methodology: The data for this study used the 2021 KOTRA GCL Test Data, and multiple regression analysis was performed using SPSS 26. As corporate competency, human capital and related capital of intellectual capital theory were utilized, and the global network level of social network theory was also utilized. As an additional analysis, corporate characteristics factors were used. Results: First, the level of global mindset of human capital acted as a positive factor in management performance, and the level of professional manpower did not achieve significant results. Second, related capital acted as a positive factor in corporate performance. Third, from the perspective of social network theory, the global network level of companies acted as a positive factor in management performance. Finally, the relationship between corporate characteristics and management performance was marginally significant. Conclusions: In order to improve the business performance of a company in a market shock such as the COVID-19 pandemic, it is required to strengthen the level of network construction with customers and increase the level of intellectual capital that a company has.

• Journal of computational fluids engineering
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• v.15 no.2
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• pp.79-85
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• 2010

Aerodynamic design optimization of rotor airfoil has been performed with advanced design method for improved aerodynamic characteristics of ONERA airfoils. A multiple response surface method is used to consider various requirements in rotor airfoil design. Shape functions for mean camber line are proposed to extend possible design domain. Numerical simulations are performed using KFLOW, a Navier-Stokes solver with shear stress transport turbulence model. The present design method provides favorable configurations for the high performance rotor airfoil. Resulting optimized airfoils give better aerodynamic performance than the baseline airfoils.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.55-59
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• 2010

Aerodynamic design optimization of rotor airfoil has been performed with advanced design method for improved aerodynamic characteristics of ONERA airfoils as a baseline. A multiple response surface method is used to consider various consider various constraints in rotor airfoil design. Airfoil surface and mean camber line are modified using various shape functions. Numerical simulations are performed using KFLOW, a Navier-Stokes solver with shear stress transport turbulence model. The present design method provides favorable configurations for the high performance rotor airfoil. Resulting optimized air foils give better aerodynamic performance than the baseline airfoils.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.240-245
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• 2010

Jacket matrices, motivated by the complex Hadamard matrix, have played important roles in signal processing, communications, image compression, cryptography, etc. In this paper, we suggest a novel approach to design a simple class of space-time block codes (STBCs) to reduce its peak-to-average power ratio. The proposed code provides coding gain due to the characteristics of the complex Hadamard matrix, which is a special case of Jacket matrices. Also, it can achieve full rate and full diversity with the simple decoding. Simulations show the good performance of the proposed codes in terms of symbol error rate. For generality, a kind of quasi-orthogonal STBC may be similarly designed with the improved performance.