• Journal of the Institute of Electronics and Information Engineers
• /
• 제50권2호
• /
• pp.35-46
• /
• 2013

As a rapid increase of mobile network usage, many studies on solution for network traffic's demand problem have been done. Especially network environment measurement area provides basis for solving network traffic's demand problem by finding causes of problems through accurate network analysis. However, as increase of demand for smartphone, we should consider effects of mobile platform's property measuring mobile network. In this paper, we design a network traffic measurement system considering mobile platform. Through the information from packets, this system calculates packet transmission delay and throughput. We minimize computation cost required for a mobile device that is a client in this system. When fully using network resources, we found that Wi-Fi has shorter transmission delay, higher maximum throughput and lower loss rate than 3G, Android has shorter transmission delay and higher maximum throughput than iOS, and UDP has longer transmission delay and higher maximum throughput through this system.

• The Journal of the Acoustical Society of Korea
• /
• 제20권8호
• /
• pp.12-18
• /
• 2001

In this paper, we propose the Recurrent Neural Predictive HMM (RNPHMM). The RNPHMM is the hybrid network of the recurrent neural network and HMM. The predictive recurrent neural network trained to predict the future vector based on several last feature vectors, and defined every state of HMM. This method uses the prediction value from the predictive recurrent neural network, which is dynamically changing due to the effects of the previous feature vectors instead of the stable average vectors. The models of the RNPHMM are Elman network prediction HMM and Jordan network prediction HMM. In the experiment, we compared the recognition abilities of the RNPHMM as we increased the state number, prediction order, and number of hidden nodes for the isolated digits. As a result of the experiments, Elman network prediction HMM and Jordan network prediction HMM have good recognition ability as 98.5% for test data, respectively.

• Management & Information Systems Review
• /
• 제31권4호
• /
• pp.517-538
• /
• 2012

The purpose of this study is to explore key factors that influence the intention of continuous use of social network service users in the online environment. Since the intention of continuous use is one of the most critical factors in the profit model of social network service, the findings of this study should be useful to the SNS firms. This study use the personal and network aspects as major behavior intention of that influence user's attachment to a social network service. The results are summarized as follows. First, use motivation in self-determination have effects on emotional attachment, information sharing intention, loyalty. The world's most leading social network services now, the social network service has developed very fast as a kind of new online service. During the past few years, the number of Twitter's registered users around the world has already exceeded 170 million. Not only have the United Sates, many countries around the world have also been hit by the wave of SNS, including those in Korea. Since the intention of continuous use is one of the most critical factors in the profit model of social network service, the findings of this study should be useful to the SNS firms. We need to continue the study of social network.

• ETRI Journal
• /
• 제25권1호
• /
• pp.34-40
• /
• 2003

This paper considers a TMN-based management system for the management of public ATM switching networks using a four-level hierarchical structure consisting of one network management system, several element management systems, and several agent-ATM switch pairs. Using Jackson's queuing model, we analyze the effects of one TMN command on the performance of the component ATM switch in processing local calls. The TMN command considered is the permanent virtual call connection. We analyze four performance measures of ATM switches- utilization, mean queue length and mean waiting time for the processor directly interfacing with the subscriber lines and trunks, and the call setup delay of the ATM switch- and compare the results with those from Jackson's queuing model.

• ETRI Journal
• /
• 제30권2호
• /
• pp.255-260
• /
• 2008

We compare the performance of a wavelength remodulated wavelength-division-multiplexed passive optical network implemented using Manchester-coded or inverse-return-to-zero (IRZ)-coded signal downstream and non-return-to-zero remodulated signal upstream. We investigate the effects of varying differences between downstream and upstream bit rates on the two coding schemes. When the bit rate ratio of upstream to downstream is less than or equal to 50%, the performance of Manchester coding is better than that of IRZ coding. However, when the bit rate ratio of upstream to downstream is higher than 50%, Manchester code requires appropriate time delay between upstream and downstream signals, whereas IRZ code needs reduced extinction ratio in the downstream signal.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 한국농공학회 2002년도 학술발표회 발표논문집
• /
• pp.453-456
• /
• 2002

In this study, the effect of DEM resolution (15m, 30m, 50m, 70m, 100m, 200m, 300m) on the hydrological simulation was examined using BASINS (Better Assessment Science Integrating point and Nonpoint Source) for Heukcheon watershed (303.3km2) data from 1998 to 1999. Generally, as the cell size of DEM increased, topographical changes were observed as the original range of elevation decreased. The processing time of watershed delineation and river network needed more time and effort on smaller cell size of DEM. The larger DEM demonstrated had some errors in the junction of river network which might effects on the simulation of water quantity and quality. The area weighted average watershed slope became lower but the length weighted average channel slope became higher as the DEM size increased. DEM resolution affected substantially on the topographical parameter but less on the hydrological simulation. Considering processing time and accuracy on hydrological simulation DEM mesh size of 100m is recommended for this watershed.

• Journal of Digital Contents Society
• /
• 제18권1호
• /
• pp.231-238
• /
• 2017

Today, as a means of online communication, the use of emoticons is activated in SNS. Emoticon is an important element to share impact effects and fun together with various content design attempts. In this paper, we analyze the expression patterns changed through development process of emoticons, and analyze characteristics and effects of emoticons which are combined with traditional culture among the types of emoticons currently used.

• Journal of Families and Better Life
• /
• 제26권5호
• /
• pp.315-332
• /
• 2008

The purpose of this study was to investigate the relative effects of human capital and social capital on the economic well-being of late middle-aged Koreans. The data from the first wave of KLoSA (Korean Longitudinal Study of Aging) aged 50-64 were used (n=4,040). The major findings were as follows: First, human capital and social capital are both resources that can contribute to increasing the economic well-being of the middle-aged. Second, the relative contribution of human capital to the economic well-being of the middle-aged varied by the level of social capital, including formal network and informal network. Third, the relative contribution of social capital to the economic well-being of the middle-aged varied by the level of human capital, including employment type and educational attainment. Based on empirical results, the implications for social investment in human capital and social capital were provided.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• 제50권7호
• /
• pp.333-339
• /
• 2001

The transmission networks are not perfect conductors and a percentage of the power generated is therefore lost before it reaches the loads. This network loss effects to the cost of suppling power to consumers, and must be considered if the most efficient dispatch and location of generators and loads is to be achieved. In this paper, we propose an approximate calculation of marginal loss factors to analyze characteristics of transmission loss of KEPCO power system. These static marginal loss factors are approximately calculated based on the KEPCO's expected summer peak load data of year 2000.

• Journal of the Korea Safety Management & Science
• /
• 제18권3호
• /
• pp.137-145
• /
• 2016

To promote the efficiency of production process of small and medium sized company, government conducts production information business that collects and analyzes information of production field automatically and helps process' controlling and supervising by supporting costs of purchase, installment, etc. of hard-software and network related to middle and small sized company intending e-Manufacturing of production field with computer and information & communication network. As a result, the number of middle and small sized companies that introduce and manage production information system is increased. Therefore, the purposes of this research are to arrange contents of production information system introduced to solve current problems of middle and small sized companies and analyze effects of small and middle sized companies' introduction through example companies.