• 경영과학
• /
• 제23권3호
• /
• pp.63-75
• /
• 2006

There are many kinds of research on web graph, most of them are focus on the hyperlinked structure of the web graph. Well known results on the web graph are rich-get-richer phenomenon, small-world phenomenon, scale-free network, etc. In this paper, we define 3 new directed web graph, so called the Web Usage Pattern Graph (WUPG), that nodes represent web sites arid arcs between nodes represent a movement between two sites by users' browsing behavior. The data to constructing the WUPG, approximately 56,000 records, are gathered from some users' PCs. The results analysing the data summarized as follows : (i) extremely rich-get-richer phenomenon (ii) average path length between sites is significantly less than the previous one (iii) less external hyperlinks, more internal hyperlinks.

• 한국경영과학회지
• /
• 제27권3호
• /
• pp.59-74
• /
• 2002

This study investigates two basic operations of mobility management of PCNs (Personal Communication Networks), i.e., the location update and the paging of the mobile terminal. From the realistic consideration that a user either moves through several cells consecutively or stays in a cell with long time, we model the mobility pattern by introducing two types of CRT (Cell Residence Time). Mobility patterns of the mobile terminal are classified Into various ways by using the ratios of two types of CRT. Cost analysis is performed for distance-based and movement-based location update schemes combined with blanket polling paging and selective paging scheme. It is demonstrated that in a certain condition of mobility pattern and call arrival pattern, 2-state CRT model produces different optimal threshold and so, is more effective than IID ( Independently-Identically-Distributed) CRT model. An analytical model for the new CRT model is compact and easily extendable to the other location update schemes.

• 한국IT서비스학회지
• /
• 제11권3호
• /
• pp.89-101
• /
• 2012

The study investigated if IT investment in Korean financial markets for the past 18 years has grown following the s-curve pattern based on Nolan's growth model in order to find the correlation between IT investment and management performance in the financial industry. According to the research finding it can be said that the overall financial markets maintain s-curve pattern, and IT investment is related to management performance, particularly increase in total assets and net profit. However, each sector has defining features of growth patterns. The banking industry has grown similarly to the s-curve, and the insurance industry also shows the s-curve but it looks more like linear pattern. In terms of securities industry, its growth patterns can hardly be considered s-curve due to the irregular changes. his research outcome illustrates the analysis of IT growth patterns in the financial industry and thus, it is expected to be a useful reference when deciding the appropriate time for IT investment in the financial industry.

• 수산해양교육연구
• /
• 제24권5호
• /
• pp.653-661
• /
• 2012

The purpose of this research is to analyze teacher's lesson language pattern based on robot class. For this research as an analytical tool AF (Advanced Flanders) was utilized. Actually ClassReport ver 1.0 computer program was used in the process of input data. From the results of the Flanders index, The major instruction sequences were 4-8-3 in elementary school and 4-8 in middle school. The teacher's remarks in robot class in the elementary school rank 'instruction', 'question'. And In the middle school rank 'instruction' and 'positive advice' are very high ratio, but 'indication' is low ratio. The teacher constantly teach and ask question ratio in the middle school was higher than elementary school. But a tendency for non-indication was low ratio in the middle school than elementary school. These results could provide effective cues and information on how to to improve instruction.

• 한국기계가공학회지
• /
• 제3권3호
• /
• pp.32-38
• /
• 2004

Recently, the system of high speed milling(HSM) is widely used for reducing the operation time and maximizing efficiency of work. The most research of high speed milling system is still leaves much to be desired. Specially the research of mass pocket high speed processing with high precision is the first and probably the last. So this paper showed mass pocket processing of high precision with a duralumin and then confirmed a cause of inferior goods through the CAD/CAM pattern simulation and experimentation. And this paper showed high speed processing system reduce the rate of inferior from this optimal pattern.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.589-590
• /
• 2006

Recently, research for the micro printing technology has begun to get into the spotlight. It is due to the superior price competitiveness to existent semi-conductor process for manufacturing some parts of display unit, electronic paper, RF-ID information device, and so on. This paper present screen printing process not for paper publication but for parts of electronics such as PDP wall, LCD CF, and so on. There are two major issues. The first one is how to get a fine and even line pattern. The other one is how to get the same patterns in large area. In this research, we present the design, equipment, and process control of screen printing in order to overcome these issues.

• Applied Microscopy
• /
• 제46권2호
• /
• pp.89-92
• /
• 2016

The bluegill Lepomis macrochirus is an invasive species, not native to Korea, introduced for aquaculture. This species is ranked as a new top predator due to its massive aquatic carnivorous and herbivorous nature by acute vision and the absence of a natural enemy. The visual cells of the retina of L. macrochirus are composed of short single cones and equal double cones and long and bulky rods by light and electron microscopes. In particular, the cones show a regular square mosaic arrangement. This pattern is widely considered as a strong predator. With regard to the visual system, this mosaic pattern may closely be related to a dynamic visual acuity to track and hunt prey.

• 한국자동차공학회논문집
• /
• 제19권3호
• /
• pp.16-22
• /
• 2011

This paper presents the potential of in-vehicle data recorder system for monitoring aggressive driving patterns and providing feedback to drivers on their on road behaviour. This system can detect 10 risky types of drivers' driving patterns such as aggressive lane change, sudden brakes and turns with acceleration etc. Vehicle dynamics simulation and vehicle road test have been performed in order to develop driving pattern recognition algorithms. Recorder systems are installed to 50 buses in a single company. Drivers' driving behaviour are monitored for 1 month. The drivers' risky driving data collected by the system are analyzed. Aggressive lane change in 50km/h below is a cause in overwhelming majority of risky driving pattern.

• International Journal of Reliability and Applications
• /
• 제10권1호
• /
• pp.1-15
• /
• 2009

Even though the impact of manufacturing quality to reliability is not considered much as well as that of design area, a major cause of an early failure of the product is known as manufacturing problem. This research applies two different types of neural network algorithms, the Back propagation (BP) algorithm and Learning Vector Quantization (LVQ) algorithm, to identify and classify the nonrandom variation pattern on the control chart based on knowledge-based diagnosis of dimensional variation. The performance and efficiency of both algorithms are evaluated to choose the better pattern recognition system for auto body assembly process. To analyze hundred percent of the data obtained by Optical Coordinate Measurement Machine (OCMM), this research considers an application in which individual observations rather than subsample means are used. A case study for analysis of OCMM data in underbody assembly process is presented to demonstrate the proposed knowledge-based pattern recognition system.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제11C권2호
• /
• pp.12-17
• /
• 2001

In this work, the correlation between the PD Patterns and the electrical tree propagation has been investigated by use of the specimen removed from the insulation of the real 154 kV XLPE underground power cables. As a result, it could be deduced that the PD pattern regarding electrical trees depends on their type which could be classified into three different distinct groups such as branch-bush mixed. Considering the results of our investigation, if the partial discharge magnitude is only considered for the diagnosis of the cable system, it is possible to draw a wrong decision. Therefore, it is possible to propose that the time characteristics of PD pattern should be taken into account for the diagnosis of the cable system in addition to the conventional $\Phi$-q-n characteristics.