• Journal of Industrial Technology
• /
• v.26 no.B
• /
• pp.191-198
• /
• 2006

In this paper, we focus on a question. Which is better between time-based location update method and movement-based location update method? Or, does any other method combining the two methods show better performance? For the question, we propose a hybrid location update scheme, which integrates the time-based and the movement-based methods. In the proposed scheme, a mobile terminal updates its location after n cell boundary crossing and a time interval of T, or the inverse. We derive an analytical solution for the performance of the hybrid scheme with exponential cell resident time. From the numerical analysis, we conclude that the movement-based method seems to have better performance than the time-based and hybrid methods, that is the optimal costs occur at T=0.

• Journal of Information Technology Services
• /
• v.12 no.4
• /
• pp.349-367
• /
• 2013

In MANET, the AODV routing protocol with on-demand method has a problem in large control packet overhead. In order to improve this, we first need a comprehensive analysis of correlation between performance metrics and factors affecting the performance of AODV. Selected parameters based on this analysis make it enable to be a more accurate and fair performance analysis, as well as to reduce the time and effort when constructing a scenario for performance analysis. In this paper, various scenarios are configured to apply AODV by varying the values of factors affecting the performance with network simulator QualNet 5.0, and then the results are analysed using performance metrics proposed by IETF MANET working group. This paper also founds a correlation between performance metrics and factors affecting the performance for AODV routing protocol, choosing the values of factors that represent many of the most maximum and minimum values of each performance metrics, and proposes optimal simulation parameters for a more accurate performance evaluation of routing protocols with minimal scenario in experiments. Next, performance comparison of AODV, DSR and DYMO routing protocols based on the proposed simulation parameters is shown which provides a comparative analysis on the performance of on-demand routing protocols. Results of this paper could be very useful for the researcher or service provider who wants to find nice simulation environment or select a proper routing protocol.

• Journal of Korean Clinical Health Science
• /
• v.3 no.4
• /
• pp.476-489
• /
• 2015

Purpose. The purpose of this study was to investigate the evidence-based pain management knowledge, performance and Evidence-Based Practice(EBP) attitude of nurses at small-medium sized hospitals. Methods. The sample of this study were 214 nurses. Data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation and stepwise multiple regression using SPSS/Win 21.0 Results. Evidence-based pain management knowledge score averaged $3.95{\pm}0.43$, with significant differences depending on clinical experiences. Performance score averaged $3.77{\pm}0.51$. EBP attitude score averaged $3.21{\pm}0.57$, and significant differences were evident depending on hospital division and clinical setting. Evidence-based pain management knowledge and EBP attitude were significant predictors of evidence-based pain management performance. Conclusions. This result indicates that education and training programs to facilitate evidence-based pain management knowledge, performance, and EBP attitude are needed among nurses.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.5
• /
• pp.49-56
• /
• 2016

Increasing Internet traffic and forwarding table size need high performance IP address lookup engine which is a crucial function of routers. For finding the longest matching prefix, trie-based or its variant schemes have been widely researched in software-based IP lookup. As a software router, we enhance the IP address lookup engine using GPU which is a device widely used in high performance applications. We propose a data structure for multibit trie to exploit GPU hardware efficiently. Also, we devise a novel scheme that the root subtrie is loaded on Shared Memory which is specialized for fast access in GPU. Since the root subtrie is accessed on every IP address lookup, its fast access improves the lookup performance. By means of the performance evaluation, our implemented GPU-based lookup engine shows 17~23 times better performance than CPU-based engine. Also, the fast access technique for the root subtrie gives 10% more improvement.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.25 no.4
• /
• pp.52-60
• /
• 2017

This paper forces on the analysis of the overall outcome regarding Performance Based Logistics(PBL) application for Air Weapon System. We used data from domestically developed aircraft such as KT/A-1 and T-50 as well as data from foreign F-15K aircraft and F100 Engine to analyze the current ROKAF PBL application results. Furthermore, this paper thus suggests various techniques to maximize the outcome of user-based PBL performance such as clarifying the responsibility between customer and the company, developing standardized PBL performance index under TLCSM, PBL related maintenance capacity development, wartime PBL implementation process of domestic/foreign companies and many other schemes based on the analyzed data.

• Steel and Composite Structures
• /
• v.27 no.5
• /
• pp.613-622
• /
• 2018

The requirement to safe and economical buildings caused to the exploitation of nonlinear capacity structures and optimization of them. This requirement leads to forming seismic design method based on performance. In this study, concentrically braced frames (CBFs) have been optimized at the immediate occupancy (IO) and collapse prevention (CP) levels. Minimizing structural weight is taken as objective function subjected to performance constraints on inter-story drift ratios at various performance levels. In order to evaluate the seismic capacity of the CBFs, pushover analysis is conducted, and the process of optimization has been done by using Bee Algorithm. Results indicate that performance based design caused to have minimum structural weight and due to increase capacity of CBFs.

• Journal of Positioning, Navigation, and Timing
• /
• v.8 no.4
• /
• pp.225-232
• /
• 2019

The satellite-based ionospheric model consists of local first-order plane function parameters for individual satellites and provides excellent accuracy in the flat ionospheric environment of the Korean Peninsula. This paper analyzes the performance of such model under the rapid changes in the ionosphere. Rapid changes in the ionosphere were observed in Korea from September to October 2014, and a satellite-based ionosphere model was applied to Wide Area Differential GPS (WADGPS) to analyze the navigation performance and the performance of estimating ionospheric delay errors. After processing the test data, it was confirmed that there was a deterioration in navigation performance and extrapolation performance in low-latitude areas and analyzed the cause.

• Proceeding of KASS Symposium
• /
• 2006.05a
• /
• pp.49-57
• /
• 2006

Performance based seismic design is a very efficient method in evaluating the seismic capacity of building. In this study, the method estimating the performance point of the spatial structures based on capacity spectrum method(CSM) is proposed. And for efficient evaluation for the performance point of the spatial structures, the algorithm to convert spatial structural system to ESDOF system is proposed. Its efficiency is confirmed by comparing with time history analysis of full model. And dynamic behaviors of spatial structures are examined by using this method. At last, evaluation of structural performance according to variation of stiffness after plastic deformation is carried out.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.1
• /
• pp.130-133
• /
• 2020

Smart pig farm which is based on IoT has been widely adopted by many pig farmers. In order to achieve optimal control of smart pig farm, the relation between environmental conditions and performance metric should be characterized. In this study, the relation between multiple environmental conditions including temperature, humidity and various performance metrics, which are daily gain, feed intake, and MSY, is analyzed based on data obtained from 55 real pig farm. Especially, based on preprocessing of data, various regression based machine learning algorithms are considered. Through performance evaluation, we show that the performance can be predicted with high precision, which can improve the efficiency of management.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.1248-1253
• /
• 2009

Although there have been many efforts to reduce accidents on construction sites, such accidents continue to occur. New technologies have recently been developed to improve safety and their performance needs to be evaluated to determine their suitability prior to the application. The assessment for safety performance mainly is conducted depending on qualitative and subjective judgment of supervisors. However, there are rarely proper approaches to assess such qualitative measures. Therefore, we propose a fuzzy-based approach to assessing the performance of a new technology. The assessment of a new technology, called a mobile detector (MD), was carried out as a case study. The output is compared with those by a numerical simulation. As a result, the fuzzy-based performance assessment is shown to be appropriate for this evaluation.