• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.91-97
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• 2016

This paper evaluates the equalization algorithm of FC-MMA (Fast Convergence-Multi Modulus Algorithm) and RMMA (Region based Multi Modulus Algorithm) for the compensation of intersymbol interference which is due to the distortion of communication channel. In order to obtain the error signal for adaptive equalization, the FC-MMA use the modified dispersion constant considering the number of signal symbol, the RMMA separates the 4 region which every symbol points are located, then reduce the symbol point based on this region into constant modulus symbol point. By applying the different principle in order to get the error signal for the updating the tap coefficient of adaptive equalizer, it has the different equalization performance by these error signal. The computer simulation was performed in order to compare the different equalization performance in this paper. The performance index includes the output signal constellation, the residual isi and maximum distortion that is for the convergence characteristics, the SER. As a result of computer simulation, RMMA has more good performance in the residual isi, maximum distortion after in steady state and SER performance than FC-MMA, but not in convergence speed to reach the steady state.

• International Commerce and Information Review
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• v.14 no.2
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• pp.201-225
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• 2012

Developing new technologies and launching new products require a huge sum of money for Research and Development, and there is also market uncertainty. Comparing to advanced countries' companies, Korea's exporting companies have less investment cost in size for R&D and insufficient technology assets accumulated. Therefore, through the open innovation, they should use external technology and enhance the efficiency of the relatively little R&D investment. This paper draws the factors influencing the innovations of Korea's exporting companies, and then it analyses how each innovation influences export performance. First, innovations are devided into two; closed and open innovation. Multiple regression analysis has been done, considering influence factors of innovation such as company's characteristics factors, research's characteristics factors and products characteristics factors to be independent variables, and export performance to be a dependent variable. It shows that firm size and new products launching period have positive effects on each innovation, but research capability and research performance have positive effects only on closed innovation. And open innovation has positive effects on export performance, but closed innovation doesn't have.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.3
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• pp.307-316
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• 2016

A multiple radar system is comprised of early warning radar for fast detection of a target and air defense radar for precision intercept. For this reason, target take-over process is required between the two radars. The target take-over should be performed at an appropriate time by consideration of stable tracking and effective fire control. In this paper, operation characteristics of multiple radar system are analyzed and target take-over time determination method using estimation of target tracking performance is proposed for high-velocity targets. The proposed method is validated with ballistic target defense scenarios in the developed integrated simulator.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.379-389
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• 2023

According to the Korea Urban Air Mobility (K-UAM) Concept of Operation (ConOps), the Global Navigation Satellite System (GNSS) is recommended as the primary navigation system and the performance specification will be implemented considering the standard of Performance Based Navigation (PBN). However, by taking into account the characteristics of an urban environment and the concurrent operations of multiple UAM aircraft, the current PBN standards for civil aviation seem difficult to be directly applied to an UAM aircraft. Therefore, by referring to technical documents published in the literature, this paper examines the feasibility of applying the proposed performance requirements to K-UAM, which follows the recommendation of navigation performance requirements for K-UAM. In accordance with the UAM ConOps, the UAM aircraft is anticipated to maintain low altitude during approach and landing phases. Subsequently, the navigation performance degradation could occur in the urban environment, and the primary degradation factor is identified as multipath error. For this reason, to ensure the safety and reliability of the K-UAM aircraft, it is necessary to analyze the degree of performance degradation related to the urban environment and then propose an alternative aid to enhance the navigation performance. To this end, the aim of this paper is to model the multipath effects of the GNSS in an urban environment and to carry out the simulation studies using the real GNSS datasets. Finally, the initial navigation performance requirement is proposed based on the results of the numerical simulation for the K-UAM.

• Journal of Korean Clinical Health Science
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• v.8 no.2
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• pp.1398-1407
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• 2020

Purpose: The purpose of this study is a technical study to understand the relationship between the recognition and performance of core basic nursing skills of nursing college students who are ahead of clinical practice, and satisfaction with their major. Method: The subjects were 208 second-year students enrolled in the four-year nursing department located in J City and C City. General characteristics, characteristics of clinical practice, and recognition of the importance of core basic nursing skills, performance, and satisfaction with majors were investigated. Descriptive statistics, t-test, analysis of variance, multiple regression analysis and IPA are performed for data analysis Results: The results are follows. The results are follows. First, the performance was lower than that of the core basic nursing skills (p<.001). As a result of comparing the importance recognition and performance of the core basic nursing items, the importance recognition was significantly compared to the performance level in all 20 items. It showed high results. Second, it was found that there was a significant positive correlation (r=.40, p<.01) with major satisfaction in core basic nursing performance. Conclusion: These results highlight the need to develop education. It is necessary to establish a learning strategy through various learning guidance methods and self-directed learning that can improve the performance of items with low performance, although recognized as important through the Core Basic Nursing IPA for nursing students who are about to practice clinical practice. It is suggested to do repeated research applied.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1198-1204
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• 2010

This study was conducted to investigate the effects of dietary supplementation with multiple enzymes composed of phytase plus carbohydrolases (ROVABIO$^{(R)}$ Max, RM) on growth performance, nutritional availability and intestinal viscosity in broiler chicks. A total of one thousand, one-day-old male broiler chicks were randomly allotted into treatment groups that received one of five experimental diets for 32 days. Each group consisted of 40 birds and all experiments included five replicates. The dietary treatments included PC (a positive control diet), NC1 (65 kcal/kg, 0.15% and 0.10% less ME, available phosphorus and calcium levels, respectively, than the PC diet), NC2 (85 kcal/kg, 0.20% and 0.10% less ME, available phosphorus and calcium levels, respectively, than the PC diet), NC1+RM (NC1 plus ROVABIO$^{(R)}$ Max) and NC2+RM (NC2 plus ROVABIO$^{(R)}$ Max). The average body weights, daily body weight gains and feed conversion rates of the chicks fed a diet containing RM improved significantly or tended to improve. The treatments also had no effect on the carcass characteristics or blood parameters, but the viscosity of the intestinal contents of the chicks fed the diet containing RM was significantly lower than that of chicks in the NC without RM groups. Additionally, chicks fed the dietary RM showed increased breaking strength and ash content of the tibia when compared to chicks that received the non-RM diets. Taken together, the results of the present study indicated that the addition of multiple enzymes consisting of phytase plus NSP enzymes improved the growth performance and mineral status of the tibia in broiler chickens fed corn-wheat-soybean meal-based diets with reduced levels of nutrients. Further, these findings suggest that the improved animal performance is associated with reduced intestinal viscosity by the dietary enzyme complex.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.1
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• pp.39-58
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• 2024

Tunnel Boring Machines (TBM) use multiple disc cutters to excavate tunnels through rock. These cutters wear out due to continuous contact and friction with the rock, leading to decreased cutting efficiency and reduced excavation performance. The rock's abrasivity significantly affects cutter wear, with highly abrasive rocks causing more wear and reducing the cutter's lifespan. The Cerchar Abrasivity Index (CAI) is a key indicator for assessing rock abrasivity, essential for predicting disc cutter life and performance. This study aims to develop a new method for effectively estimating CAI using rock strength, petrological characteristics, linear regression, and machine learning. A database including CAI, uniaxial compressive strength, Brazilian tensile strength, and equivalent quartz content was created, with additional derived variables. Variables for multiple linear regression were selected considering statistical significance and multicollinearity, while machine learning model inputs were chosen based on variable importance. Among the machine learning prediction models, the Gradient Boosting model showed the highest predictive performance. Finally, the predictive performance of the multiple linear regression analysis and the Gradient Boosting model derived in this study were compared with the CAI prediction models of previous studies to validate the results of this research.

• Journal of Korean Academy of Nursing Administration
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• v.22 no.5
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• pp.471-479
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• 2016

Purpose: This study was conducted to evaluate the level of safety climate, fatigue, and safety performance and to identify the impact of safety climate and fatigue on the safety performance of operating room nurses. Methods: The study design was a descriptive survey. Participants were 174 operating room nurses from two general hospitals and two university hospitals in S and D cities. Three structurally designed questionnaires were used to evaluate their safety climate, fatigue, and safety performance. Collected data were analyzed using descriptive analysis, t-tests, ANOVAs, Pearson correlation coefficient, and stepwise multiple regression. Results: Safety performance of operating room nurses had a mean of 3.26 on a 5-point scale. 'Current department career'(${\beta}=.17$, p=.006) and 'safety climate (work-unit contribution) (${\beta}=.63$, p<.001) accounted for 39% of the variance in operating room nurses' safety performance. Conclusion: Findings indicate that work-unit contribution towards safety climate is an important factor in increasing operating room nurses' safety performance. Therefore, it is essential to find motivational properties consistent with the characteristics of the operating room environment.

• KIISE Transactions on Computing Practices
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• v.22 no.4
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• pp.163-169
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• 2016

Lustre is a scalable, distributed file system, which is popular in the field of high-performance computing. Recently, the advent of SSD has enabled high-performance storage hardware, but software development requires further improvement. In this paper, we analyzed performance of the Lustre system using SSD via extensive experimentation. We compared performance of Lustre on SSDs and HDDs in terms of file read/write throughputs and metadata access latencies. Our experimental results showed that 1) SSDs improve metadata access performance due to fast random read/write access of SSD characteristics, and 2) SSD are benefited to a greater extent under multiple threads and large numbers of small sized files.

• Journal of Korean Academy of Nursing Administration
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• v.20 no.4
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• pp.426-436
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• 2014

Purpose: This study was conducted to identify factors that affect nursing performance; Those factors are personal characteristics, sub-categories of empowerment and job satisfaction of clinical nurses. Methods: Data were collected from November 24, 2012 to March 11, 2013, and participants were 451 hospital nurses in 6 hospitals. Descriptive statistics, t-test, one-way ANOVA, Pearson correlation coefficient, and stepwise multiple regression were used for data analysis. Results: Nurses who were older, married, highly educated, in the position of charge nurse, and with longer clinical careers showed relatively higher empowerment, higher job satisfaction, and higher nursing performance than others. Also, there were strong correlations between nursing performance and empowerment (r=.576)/job satisfaction (r=.617). Factors predicted nursing performance were relationship with coworkers (${\beta}=.398$), duty (${\beta}=.181$), promotion system (${\beta}=.134$), and turnover intention (${\beta}=-.109$). Factors predicting job satisfaction were competency of empowerment (${\beta}=.249$), and clinical career (${\beta}=.151$). These 6 factors explained 55.2% of the variance in nursing performance (F=93.37, <.001). Conclusion: Regarding human resource management, relationship with co-workers is a changeable factor. Therefore nursing organizations should apply these factors in human resource management to enhance nursing performance and achieve organizational goals.